TY - JOUR TI - High-power III-nitride emitters for solid-state lighting AU - Krames, M. R. AU - Collins, J. B. D. AU - Gardner, N. F. AU - Gotz, W. AU - Lowery, C. H. AU - Ludowise, M. AU - Martin, P. S. AU - Mueller, G. AU - Mueller-Mach, R. AU - Rudaz, S. AU - Steigerwald, D. A. AU - Stockman, S. A. AU - Wierer, J. J. T2 - Physica Status Solidi a-Applied Research AB - High-power, large-area InGaN/GaN quantum-well heterostructure light-emitting diodes based on an inverted, or “flip-chip”, configuration are described. These devices are mounted in specially designed high-power (≈1–5 W) packages and exhibit high extraction efficiency and low operating voltage. In the blue wavelength regime, output powers greater than 250 mW (1 × 1 mm2 device) and 1 W (2 × 2 mm2 device) are delivered at standard operating current densities (≈50 A/cm2), corresponding to “wall-plug” efficiencies of 22%–23%. Employing phosphors for the generation of white light, these same devices achieve luminous efficiencies greater than 30 lm/W. DA - 2002/// PY - 2002/// DO - 10.1002/1521-396x(200208)192:2<237::aid-pssa237>3.0.co;2-i VL - 192 IS - 2 SP - 237-245 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000177750700001&KeyUID=WOS:000177750700001 ER - TY - JOUR TI - High power LEDs - Technology status and market applications AU - Steranka, F. M. AU - Bhat, J. AU - Collins, D. AU - Cook, L. AU - Craford, M. G. AU - Fletcher, R. AU - Gardner, N. AU - Grillot, P. AU - Goetz, W. AU - Keuper, M. AU - Khare, R. AU - Kim, A. AU - Krames, M. AU - Harbers, G. AU - Ludowise, M. AU - Martin, P. S. AU - Misra, M. AU - Mueller, G. AU - Mueller-Mach, R. AU - Rudaz, S. AU - Shen, Y. C. AU - Steigerwald, D. AU - Stockman, S. AU - Subramanya, S. AU - Trotter, T. AU - Wierer, J. J. T2 - Physica Status Solidi a-Applied Research AB - High power light emitting diodes (LEDs) continue to increase in output flux with the best III-nitride based devices today emitting over 150 lm of white, cyan, or green light. The key design features of such products will be covered with special emphasis on power packaging, flip-chip device design, and phosphor coating technology. The high-flux performance of these devices is enabling many new applications for LEDs. Two of the most interesting of these applications are LCD display backlighting and vehicle forward lighting. The advantages of LEDs over competing lighting technologies will be covered in detail. DA - 2002/// PY - 2002/// DO - 10.1002/1521-396x(200212)194:2<380::aid-pssa380>3.0.co;2-n VL - 194 IS - 2 SP - 380-388 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000180101800004&KeyUID=WOS:000180101800004 ER - TY - CONF TI - Measuring odor intensity with E-noses and other sensor types AU - Schiffman, S. AU - Gutierrez-Osuna, R. AU - Nagle, H.T. T2 - 9th International Symposium on Olfaction and Electronic Nose (ISOEN ‘02) A2 - D’Amico, A. A2 - Di Natale, C. C2 - 2002/// C3 - 9th International Symposium on Olfaction and Electronic Nose (ISOEN ‘02) DA - 2002/// PY - 2002/// SP - 68–72 PB - Aracne Editrice ER - TY - CONF TI - Measuring odor intensity with a photoionization detector (PID AU - Schiffman, S.S. AU - Graham, B.G. AU - Nagle, H.T. T2 - 9th international symposium on olfaction and electronic nose (ISOEN ‘02) A2 - D’Amico, A. A2 - Di Natale, C. C2 - 2002/// C3 - Technical digest. 9th international symposium on olfaction and electronic nose (ISOEN ‘02) DA - 2002/// PY - 2002/// SP - 33-34 PB - Aracne ER - TY - CHAP TI - Health effects of aerial emissions from animal production waste management systems AU - Schiffman, S.S. AU - Auvermann, B.W. AU - Bottcher, R.W. T2 - Animal Agriculture and the Environment: National Center for Manure and Animal Waste Management White Papers A2 - Rice, J. M. A2 - Caldwell, D. F. A2 - Humenik, F. J. AB - The rapid proliferation of concentrated animal feeding operations (CAFOs) over the last decadehas raised concerns about health effects of aerial emissions from animal production and waste managementsystems. These aerial emissions are predominantly a mixture of hydrogen sulfide (H2S),ammonia (NH3), volatile organic compounds (VOCs), and particulate matter (PM) (includingbioaerosols). The purpose of this paper is to review the known health effects of each of these componentsof aerial emissions from CAFOs. The potential health effects of malodors associated withthese emissions will be addressed as well. PY - 2002/// DO - 10.13031/2013.20255 SP - 225–262 PB - American Society of Agricultural and Biological Engineers ER - TY - JOUR TI - Adverse taste side effects of cardiovascular medications AU - Zervakis, J. AU - Schiffman, S.S. T2 - Geriatric Times DA - 2002/// PY - 2002/// VL - 3 IS - 1 SP - 19–23 ER - TY - JOUR TI - Chemosensory perception in elderly lung cancer patients on chemotherapy AU - Schiffman, S.S. AU - Zervakis, J. AU - Campagna, L.K. AU - Garst, J.L. T2 - Chemical Senses DA - 2002/// PY - 2002/// VL - 27 IS - 7 SP - A21 ER - TY - JOUR TI - Flavor enhancement and its positive health benefits AU - Schiffman, S.S. T2 - Aroma-Chology Review DA - 2002/// PY - 2002/// VL - 10 SP - 1–5 ER - TY - CONF TI - Power Packaging Techniques for Low and Higher Voltage Systems AU - Hopkins, Douglas C. AU - Bowers, John S. T2 - 17th Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC) C2 - 2002/3/11/ C3 - 17th Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC) CY - Dallas, Tx DA - 2002/3/11/ PY - 2002/3/11/ ER - TY - CONF TI - 52nd Electronic Components and Technology Conference 2002. (Cat. No.02CH37345) T2 - Proceedings of 52nd Electronic Components and Technology Conference C2 - 2002/// C3 - 52nd Electronic Components and Technology Conference 2002 (Cat No 02CH37345) ECTC-02 DA - 2002/// DO - 10.1109/ECTC.2002.1008063 PB - IEEE UR - http://dx.doi.org/10.1109/ECTC.2002.1008063 ER - TY - JOUR TI - Aspartame: Review of Safety AU - Butchko, Harriett H. AU - Stargel, W.Wayne AU - Comer, C.Phil AU - Mayhew, Dale A. AU - Benninger, Christian AU - Blackburn, George L. AU - de Sonneville, Leo M.J. AU - Geha, Raif S., (Allergy) AU - Hertelendy, Zsolt AU - Koestner, Adalbert AU - Leon, Arthur S. AU - Liepa, George U. AU - McMartin, Kenneth E., (Methanol) AU - Mendenhall, Charles L. AU - Munro, Ian C., (Preface) AU - Novotny, Edward J. AU - Renwick, Andrew G., (Preface) AU - Schiffman, Susan S. AU - Schomer, Donald L. AU - Shaywitz, Bennett A. AU - Spiers, Paul A. AU - Tephly, Thomas R., (Methanol) AU - Thomas, John A. AU - Trefz, Friedrich K. T2 - Regulatory Toxicology and Pharmacology AB - Over 20 years have elapsed since aspartame was approved by regulatory agencies as a sweetener and flavor enhancer. The safety of aspartame and its metabolic constituents was established through extensive toxicology studies in laboratory animals, using much greater doses than people could possibly consume. Its safety was further confirmed through studies in several human subpopulations, including healthy infants, children, adolescents, and adults; obese individuals; diabetics; lactating women; and individuals heterozygous (PKUH) for the genetic disease phenylketonuria (PKU) who have a decreased ability to metabolize the essential amino acid, phenylalanine. Several scientific issues continued to be raised after approval, largely as a concern for theoretical toxicity from its metabolic components--the amino acids, aspartate and phenylalanine, and methanol--even though dietary exposure to these components is much greater than from aspartame. Nonetheless, additional research, including evaluations of possible associations between aspartame and headaches, seizures, behavior, cognition, and mood as well as allergic-type reactions and use by potentially sensitive subpopulations, has continued after approval. These findings are reviewed here. The safety testing of aspartame has gone well beyond that required to evaluate the safety of a food additive. When all the research on aspartame, including evaluations in both the premarketing and postmarketing periods, is examined as a whole, it is clear that aspartame is safe, and there are no unresolved questions regarding its safety under conditions of intended use. DA - 2002/4// PY - 2002/4// DO - 10.1006/rtph.2002.1542 VL - 35 IS - 2 SP - S1-S93 J2 - Regulatory Toxicology and Pharmacology LA - en OP - SN - 0273-2300 UR - http://dx.doi.org/10.1006/rtph.2002.1542 DB - Crossref ER - TY - CHAP TI - Age-Related Chemosensory Losses: Effect of Medications AU - Schiffman, Susan S. AU - Zervakis, Jennifer AU - Graham, Brevick G. AU - Westall, Holly L. T2 - Chemistry of Taste T3 - ACS Symposium Series AB - Significant losses in taste perception can occur with advancing age, and these losses can contribute to inadequate food intake leading to malnutrition and weight loss. Both experimental data and clinical reports suggest that medications play a major role in age-related chemosensory changes. Over 250 drugs have been reported clinically to affect the sense of taste. Taste impairments from medications include: ageusia (absence of taste), hypogeusia (diminished sensitivity of taste), and dysgeusia (distortion of normal taste). The sites of action for most pharmaceutical compounds that induce taste losses are not known, but medications can act at several levels including peripheral receptors, chemosensory neural pathways, and/or the brain. Extensive research has shown that drugs are secreted into the saliva, and salivary levels of many drugs are high enough to exert adverse effects on taste sensations either by modifying taste transduction mechanisms or by producing a taste of their own. PY - 2002/7/19/ DO - 10.1021/bk-2002-0825.ch008 SP - 94–108 PB - American Chemical Society SN - 9780841237346 9780841219267 SV - 825 UR - http://dx.doi.org/10.1021/bk-2002-0825.ch008 ER - TY - JOUR TI - Sensory acuity and reasoning in delusional disorder AU - Conway, Charles R. AU - Bollini, Anna M. AU - Graham, Brevick G. AU - Keefe, Richard S.E. AU - Schiffman, Susan S. AU - McEvoy, Joseph P. T2 - Comprehensive Psychiatry AB - Systematic research on delusional disorder (DD) is limited. The goal of this study was to assess DD patients in the following areas: sensory capacities, decision-making style, and complex reasoning. Ten DD patients and 10 matched normal controls completed the following (1) smell, taste, and vision testing; (2) a probabilistic inference test in which subjects made probability decisions; and (3) a gambling task assessing complex reasoning. No significant difference was found between DD subjects and normals for taste acuity, olfactory acuity, or olfactory discrimination. No difference in visual acuity was noted, but sample size was limited. In addition, DD subjects required significantly less data to make probability decisions than normal controls. Despite using less data, DD subjects were as certain as controls regarding the accuracy of their decisions. As for complex reasoning, DD subjects performed as well as normal controls, but tended to surmise the purpose of the task sooner than normals, a difference that approached significance. In conclusion, these results suggest no differences between DD and normal subjects regarding olfaction, taste, and vision. The reasoning studies suggest that DD subjects may have a “cognitive set” that predisposes them to make conclusions with significantly less data than normals. Further, the study suggests that this reasoning difference generalizes to events outside the DD subjects' delusional realm and can be evoked in an experimental environment. DA - 2002/5// PY - 2002/5// DO - 10.1053/comp.2002.32358 VL - 43 IS - 3 SP - 175-178 J2 - Comprehensive Psychiatry LA - en OP - SN - 0010-440X UR - http://dx.doi.org/10.1053/comp.2002.32358 DB - Crossref ER - TY - ER - TY - JOUR TI - Taste, smell and neuropsychological performance of individuals at familial risk for Alzheimer's disease AU - Schiffman, S T2 - Neurobiology of Aging AB - The purpose of the study was to determine whether there are chemosensory and neuropsychological changes that predate the onset of Alzheimer's disease in individuals at enhanced risk of developing the condition. To study this question, a unique sample of individuals (n = 33) was studied who were genetically at-risk for AD by virtue of documented multigenerational evidence of the disease (so-called multiplex families). The performance of at-risk individuals was evaluated on various smell, taste, and neuropsychological measures at baseline and 18 months later. Their performance was compared to a control group (n = 32) that was matched in age, gender, education, and race. At baseline the at-risk group performed worse than the control group on the chemosensory measures of phenethyl alcohol smell detection, smell memory, and taste memory, and on a memory measure involving recall of narrative information (Logical Memory I from the Wechsler Memory Scale- Revised). Across both sessions, the at-risk group had lower smell memory scores than the control group. At-risk status was not significantly associated with APOE status. The results of this and other studies suggest that individuals who are genetically at risk for developing AD may perform more poorly on memory and smell measures compared to those not at risk. This effect may be separate from one known genetic risk factor of AD, APOE, and supports that multiple genes are likely responsible for the disease and its associated memory and other neurocognitive symptoms. DA - 2002/6// PY - 2002/6// DO - 10.1016/s0197-4580(01)00337-2 VL - 23 IS - 3 SP - 397-404 OP - SN - 0197-4580 UR - http://dx.doi.org/10.1016/s0197-4580(01)00337-2 DB - Crossref ER - TY - ER - TY - CONF TI - Implementation of high throughput soft output viterbi decoders AU - Yeo, E. AU - Augsburger, S. AU - Davis, W.R. AU - Nikolić, B. T2 - IEEE Workshop on Signal Processing Systems AB - The architectural considerations for VLSI implementations of soft output Viterbi decoders are presented. Structural transformation of the add-compare-select structures provides high throughput with small area overhead. Modifications to the survivor memory unit and a comparison between the register exchange and memory traceback methods are highlighted. A 4 mm/sup 2/ demonstration chip, consisting of two parallel, 8-state, 7-bit soft output Viterbi decoders, has been implemented in 0.18 /spl mu/m CMOS technology, and decodes at 500 Mb/s with 1.8 V supply. These decoders are used with turbo codes, which have been demonstrated to achieve information rates close to the Shannon limit. C2 - 2002/10// C3 - IEEE Workshop on Signal Processing Systems CY - San Diego, CA DA - 2002/10// PY - 2002/10/16/ DO - 10.1109/SIPS.2002.1049700 SP - 146–151 ER - TY - JOUR TI - A Design Environment for High-Throughput, Low-Power Dedicated Signal Processing Systems AU - Davis, W.R. AU - Zhang, N. AU - Camera, K. AU - Marković, D. AU - Smilkstein, T. AU - Ammer, M.J. AU - Yeo, E. AU - Augsburger, S. AU - Nikolić, B. AU - Brodersen, R.W. T2 - IEEE Journal of Solid State Circuits AB - A hierarchical automated design flow for low-energy direct-mapped signal processing integrated circuits is presented. A modular framework based on a combined dataflow graph and floorplan description drives automatic layout generation with commercial CAD tools. Automatic characterization of layout improves system-level estimates. Simplified physical design methodologies for low supply voltages are discussed. The flow is demonstrated on a 300-k transistor test-chip, a time-division multiple-access baseband receiver, and a soft-output Viterbi decoder. An example of architectural comparison of energy efficiency is presented. DA - 2002/3// PY - 2002/3// DO - 10.1109/4.987095 VL - 37 IS - 3 SP - 420–431 KW - application specific integrated circuits KW - design automation KW - design methodology KW - integrated circuit design KW - parallel architectures KW - system analysis and design ER - TY - THES TI - A Hierarchical, Automated Design Flow for Low-Power, High-Throughput Digital Signal Processing IC’s AU - Davis, W.R. DA - 2002/// PY - 2002/// M3 - PhD Thesis PB - Electrical Engineering Department, University of California ER - TY - CONF TI - 500 Mb/s Soft Output Viterbi Decoder AU - Yeo, E. AU - Augsburger, S. AU - Davis, W.R. AU - Nikolić, B. T2 - European Solid-State Circuits Conference (ESSCIRC) C2 - 2002/9// C3 - European Solid-State Circuits Conference (ESSCIRC) DA - 2002/9// PY - 2002/9// SP - 523–526, ER - TY - CONF TI - Jitter in a wireless clock distribution system AU - Dickson, T. AU - Floyd, B. AU - O, K. AB - The jitter of a transmitted wireless clock signal has been measured and found to behave much like jitter of conventionally distributed clock signals. Noise from nearby digital circuits can degrade receiver sensitivity by reducing LNA gain and shifting the divider self-oscillation frequency. This increases clock jitter and, in extreme conditions, can cause failure in the clock receiver circuits to lock on to the transmitted clock signal. The clock can be re-locked by increasing the transmitted power. C2 - 2002/// C3 - Proceedings of the IEEE 2002 International Interconnect Technology Conference, IITC 2002 DA - 2002/// DO - 10.1109/IITC.2002.1014917 SP - 154-156 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84961695926&partnerID=MN8TOARS ER - TY - CONF TI - Wireless Interconnects for Clock Distribution AU - Floyd, B.A. AU - Guo, X. AU - Caserta, J. AU - Dickson, T. AU - Hung, C.-M. AU - Kim, K. AU - O, K.K. AB - A wireless interconnect system for clock distribution which transmits and receives microwave signals across a chip using integrated antennas, receivers, and transmitters is presented. All of the com-ponents of the system are demonstrated at 15 GHz in a 0.18-m CMOS technology. Wireless interconnection is achieved over a distance of 5.6 mm. C2 - 2002/// C3 - ACM/IEEE International Workshop on Timing Issues in the Specification and Synthesis of Digital Systems DA - 2002/// DO - 10.1145/589411.589433 SP - 105-108 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0141989608&partnerID=MN8TOARS ER - TY - CONF TI - Propagation layers for intra-chip wireless interconnection compatible with packaging and heat removal AU - Guo, X. AU - Caserta, J. AU - Li, R. AU - Floyd, B. AU - O, K.K. C2 - 2002/// C3 - IEEE Symposium on VLSI Circuits, Digest of Technical Papers DA - 2002/// SP - 36-37 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036057339&partnerID=MN8TOARS ER - TY - CONF TI - A direct-conversion receiver IC for WCDMA mobile systems AU - Reynolds, S. AU - Floyd, B. AU - Beukema, T. AU - Zwick, T. AU - Pfeiffer, U. AU - Ainspan, H. C2 - 2002/// C3 - Proceedings of the IEEE Bipolar/BiCMOS Circuits and Technology Meeting DA - 2002/// SP - 61-64 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036437922&partnerID=MN8TOARS ER - TY - CONF TI - Experimental Study on Reliability of Solder Joints under Electrical Stressing -Nano-indentation, Atomic Flux Measurement AU - Ye, H. AU - Basaran, C. AU - Hopkins, D. T2 - 2002 International Microelectronics Assembly and Packaging Society (IMAPS) International Conference on Advanced Packaging and Systems C2 - 2002/// C3 - SPIE proceedings series CY - Reno, Nevada DA - 2002/// PY - 2002/3/10/ VL - 4828 SP - 231–236 PB - Bellingham, Washington ER - TY - CONF TI - Measurement and Effects of High Electrical Current Stress in Solder Joints AU - Ye, H. AU - Hopkins, D.C. AU - Basaran, C. T2 - 35th International Symposium on Microelectronics C2 - 2002/// C3 - Proceedings of the 35th International Symposium on Microelectronics CY - Denver, Colorado DA - 2002/// PY - 2002/9/4/ SP - 427–432 ER - TY - CONF TI - Synthesis of a new class of converters that utilize energy recirculation AU - Hopkins, D.C. AU - Root, D.W. T2 - 1994 Power Electronics Specialist Conference - PESC'94 AB - A new class of switchmode power electronic circuit topologies, named energy recirculation and storage circuits (ERSCs), are described which have the characteristic of storing and recirculating energy in a return path to augment the source. A port reduction technique is developed which connects output to input and is applied to buck and boost derived converters. A description of circuit operation is given for an ideal boost/buck ERSC. Two possible applications for ERSCs are for in-situ testing of power devices and for power factor correction. The second utilizes a cascaded boost/buck ERSC as an output-regulated power-factor correction (PFC) circuit. The PFC-ERSC is evaluated and a detailed description with key equations included.< > C2 - 2002/12/17/ C3 - Proceedings of 1994 Power Electronics Specialist Conference - PESC'94 CY - Taipei, Taiwan DA - 2002/12/17/ PY - 1994/6/20/ DO - 10.1109/pesc.1994.373830 PB - IEEE SN - 0780318595 UR - http://dx.doi.org/10.1109/pesc.1994.373830 ER - TY - CONF TI - Packaging issues for next generation high voltage, high temperature power electronic modules AU - Bowers, J.S. AU - Hopkins, D.C. AU - Sarjeant, W.J. T2 - APEC 97 - Applied Power Electronics Conference AB - This paper describes packaging issues related to the next generation of high voltage (>2 kV), high temperature (200/spl deg/C to 400/spl deg/C) power electronic modules that are being developed for military, commercial and industrial applications. These applications include space, nuclear power and down-hole systems. Components, materials and processes are considered. Effects due to variations in thickness of the copper interconnect, ceramic substrate and heat spreader (baseplate) are investigated to predict the effects of thermally induced stresses. Thinner ceramic layers provide a significant increase in the thermal conductance and lower thermally induced stresses during system operation. C2 - 2002/11/22/ C3 - Proceedings of APEC 97 - Applied Power Electronics Conference CY - Atlanta, GA DA - 2002/11/22/ PY - 1997/2/27/ DO - 10.1109/apec.1997.581483 PB - IEEE SN - 0780337042 UR - http://dx.doi.org/10.1109/apec.1997.581483 ER - TY - CONF TI - A framework for developing power electronics packaging AU - Hopkins, D.C. AU - Mathuna, S.C.O. AU - Alderman, A.N. AU - Flannery, J. T2 - APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition AB - As the integration of electro-physical circuits increases, many physical components and topologies are either directly or indirectly determined by the electrical designer. This paper presents a packaging technology framework for designers to better understand, evaluate and communicate the technical needs for a 'physical circuit'. The framework goes further in proposing a systematic method to link technical power packaging issues to user requirements as the basis for developing a power electronics technology roadmap. This paper presents the framework as a three-dimensional coordinate of user requirements, levels of packaging and interfaces and pathways, cross-cut by a fourth dimension of energy forms. Examples assist the reader in understanding the framework and appreciating the potential for application of the framework in the future developments of power electronics packaging. C2 - 2002/11/27/ C3 - APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition CY - Anaheim, CA DA - 2002/11/27/ PY - 1998/2/15/ DO - 10.1109/apec.1998.647663 PB - IEEE SN - 0780343409 UR - http://dx.doi.org/10.1109/apec.1998.647663 ER - TY - CONF TI - Power packaging of a 12 kV, 240°C passive electronic module AU - Bowers, J.S. AU - Hopkins, D.C. AU - Sarjeant, W.J. T2 - APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition AB - This paper describes packaging design issues related to a high voltage (12 kV), high temperature (240/spl deg/C) power electronic module developed for military, commercial, and industrial applications. Designs guides are given for materials and qualification of components. C2 - 2002/11/27/ C3 - APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition CY - Anaheim, CA DA - 2002/11/27/ PY - 1998/2/15/ DO - 10.1109/apec.1998.647736 PB - IEEE SN - 0780343409 UR - http://dx.doi.org/10.1109/apec.1998.647736 ER - TY - CONF TI - A high speed pulser thyristor AU - Craig, A.H. AU - Hopkins, D.C. AU - Driscoll, J.C. T2 - APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition AB - A pulse power thyristor (PPT), has features optimized for pulse power applications: high di/dt, compact size and high current densities >10/sup 4/ A/cm/sup 2/. These features are enabled by enhancing the turn-on mechanism through field aided drift and a very high level of gate-cathode interdigitation. The technology allows high blocking voltage >5 kV in small, low cost packages. The device described in this paper is optimized for turn-on and, as such, is labeled a pulse power closing switch thyristor (PPCST). The device structure is briefly discussed along with details of field aided drift as a critical dynamic mechanism. A trade-off for fast turn-on shows that the dynamic resistance and leakage currents are higher than typical thyristors. A major attribute of the device design is to self limit the anode di/dt without self-destruction or having the requirement for series inductors. A dynamic test circuit was developed with the potential of greater than 110 kA//spl mu/s. Test results show that the di/dt is limited by the PPCST and not inductance. The current rise from 10% to 90% occurs within 260 ns to a peak current of 4.85 kA to yield a di/dt of 14.9 kA//spl mu/s. The 10% to 70% rise yields better than 20 kA//spl mu/s. During rapid di/dt of anode current the gate-to-cathode voltage became excessive. There, also, was an indication of possible current flow out of the gate during the same interval. Thus, an ultra-fast constant-current gate drive circuit was developed. The drive delivered 0 to 30 A in <400 ns and maintained the 30 A during the entire turn on interval. The excessive voltage was due to 5 nH of internal package inductance. C2 - 2002/11/27/ C3 - APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition CY - Anaheim, CA DA - 2002/11/27/ PY - 1998/2/15/ DO - 10.1109/apec.1998.653980 PB - IEEE SN - 0780343409 UR - http://dx.doi.org/10.1109/apec.1998.653980 ER - TY - CONF TI - Optimally selecting packaging technologies and circuit partitions based on cost and performance AU - Jacobsen, J.B. AU - Hopkins, D.C. T2 - APEC 2000 - Applied Power Electronics Conference AB - Most power electronics circuits are packaged using two or more power electronics packaging technologies. To optimally select and use several technologies that meet performance requirements at minimum cost requires a strategic partitioning of the circuit. Presented is a structured technique for optimally selecting technologies based on a relative cost diagram. Other factors, such as performance, product volume and modularity are included. C2 - 2002/11/7/ C3 - APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.00CH37058) CY - New Orleans, LA DA - 2002/11/7/ PY - 2000/2/6/ DO - 10.1109/apec.2000.826079 PB - IEEE SN - 0780358643 UR - http://dx.doi.org/10.1109/apec.2000.826079 ER - TY - CONF TI - Characterization of advanced materials for high voltage/high temperature power electronics packaging AU - Hopkins, D.C. AU - Bowers, J.S. T2 - 16th Annual Applied Power Electronics Conference - APEC 2001 AB - To achieve high reliability in next generation dense, high voltage (>1 kV DC), high temperature (200/spl deg/C to 400/spl deg/C) power electronic circuits, packaging techniques from higher voltage systems (5 kV-50 kV) need to be introduced. This paper describes advanced materials, measurement and characterization techniques for this class of systems. These systems are being developed for commercial, industrial and military applications that include supplies, drives and actuators. The results are applicable to 1200 V+IGBT based module designs. C2 - 2002/11/13/ C3 - APEC 2001. Sixteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.01CH37181) CY - Anaheim, CA DA - 2002/11/13/ PY - 2001/3/4/ DO - 10.1109/apec.2001.912498 PB - IEEE SN - 0780366182 UR - http://dx.doi.org/10.1109/apec.2001.912498 ER - TY - CONF TI - Mechanical Implications of High Current Densities in Flip Chip Solder Joints AU - Ye, Hua AU - Basaran, Cemal AU - Hopkins, Douglas T2 - ASME 2002 International Mechanical Engineering Congress and Exposition AB - The electromigration damage in flip chip solder joints of eutectic SnPb was studied under current stressing at room temperature with the current density about 1.3×104A/cm2. The diameter of the solder joints was about 140μm. The mass accumulation near anode side and void nucleation near cathode were observed during current stressing. The nano-indentation test was first time done on solder joints for electromigration test. Surface marker movement was used to measure the atomic flux driven by electromigration and to calculate the product of effective charge number and diffusivity, DxZ*, of the solder at room temperature. The effective charge number can be extracted with the solder diffusivity at room temperature known. C2 - 2002/1/1/ C3 - Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology DA - 2002/1/1/ DO - 10.1115/imece2002-33650 PB - ASMEDC SN - 0791836487 UR - http://dx.doi.org/10.1115/imece2002-33650 DB - Crossref ER - TY - JOUR TI - Sphinx parallelization AU - Baugh, Lee AU - Renau, Jose AU - Tuck, James AU - Torrellas, Josep T2 - Dept. of Computer Science, University of Illinois, Tech. Rep. UIUCDCS DA - 2002/// PY - 2002/// ER - TY - JOUR TI - Morphable multithreaded memory tiles (M3T) architecture AU - Renau, Jose AU - Tuck, James AU - Liu, Wei AU - Torrellas, Josep T2 - University of Illinois UIUC-CS Technical Report DA - 2002/// PY - 2002/// ER - TY - RPRT TI - Sphinx Parallelization AU - Tuck, James M AU - Baugh, Lee W AU - Renau, Jose AU - Torrellas, Josep DA - 2002/// PY - 2002/// ER - TY - RPRT TI - Using Performance Bounds to Guide Pre-scheduling Code Optimizations AU - Zhou, H. AU - Conte, T.M. A3 - Department of Electrical and Computer Engineering, North Carolina State University DA - 2002/9// PY - 2002/9// M3 - Technical Report, PB - Department of Electrical and Computer Engineering, North Carolina State University ER - TY - CONF TI - Smooth orthogonal signal extensions for paraunitary tree-structured filter banks AU - Jiménez, M.E.D. AU - Prelcic, N.G. C2 - 2002/// C3 - ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings DA - 2002/// VL - 2 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036297198&partnerID=MN8TOARS ER - TY - CONF TI - Polynomial extension method for size-limited paraunitary filter banks AU - Jimenez, M.E.D. AU - Prelcic, N.G. C2 - 2002/// C3 - European Signal Processing Conference DA - 2002/// VL - 2002-March UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84960896268&partnerID=MN8TOARS ER - TY - CONF TI - Semiconductor devices for fiber optic communication systems AU - Lunardi, L.M. AB - We review the state-of-the-art of heterojunction-based integrated circuit technologies that have potential applications for time division multiplexing (TDM) and wavelength division multiplexing (WDM) fiber optic communication systems. C2 - 2002/// C3 - 2002 23rd International Conference on Microelectronics, MIEL 2002 - Proceedings DA - 2002/// DO - 10.1109/MIEL.2002.1003154 VL - 1 SP - 99-102 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84906688594&partnerID=MN8TOARS ER - TY - CONF TI - 40 nm broadband SOA-Raman hybrid amplifier AU - Chen, Y. AU - Pavlik, R. AU - Visone, C. AU - Pan, F. AU - Gonzales, E. AU - Turukhin, A. AU - Lunardi, L. AU - Al-Salameh, D. AU - Lumish, S. C2 - 2002/// C3 - Conference on Optical Fiber Communication, Technical Digest Series DA - 2002/// VL - 70 SP - 390-391 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036438676&partnerID=MN8TOARS ER - TY - CONF TI - SOA characteristics for L-BAND system applications AU - Turukhin, A. AU - Lunardi, L. AU - Gonzales, E. AU - Vreeburg, K. C2 - 2002/// C3 - European Conference on Optical Communication, ECOC DA - 2002/// VL - 3 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84949009348&partnerID=MN8TOARS ER - TY - CONF TI - Statistical antenna selection for spatial multiplexing systems AU - Gore, D. AU - Heath, R. AU - Paulraj, A. C2 - 2002/// C3 - IEEE International Conference on Communications DA - 2002/// VL - 1 SP - 450-454 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036279597&partnerID=MN8TOARS ER - TY - JOUR TI - Transmit selection in spatial multiplexing systems T2 - IEEE Communications Letters AB - In this letter we solve the transmit antenna selection problem for a zero forcing spatial multiplexing system with knowledge of the channel statistics at the transmitter. We show through Wishart matrix analysis that the signal-to-noise ratio on the kth stream is a weighted Chi-squared variable with the weight equal to-the kth diagonal entry of the inverted transmit correlation matrix. We use this result to develop selection algorithms for two cases-maximizing ergodic capacity and minimizing the average probability of error. Monte Carlo simulations illustrate potential performance improvements. DA - 2002/// PY - 2002/// DO - 10.1109/LCOMM.2002.805517 VL - 6 IS - 11 SP - 491-493 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036864743&partnerID=MN8TOARS ER - TY - CONF TI - Quantized maximum ratio transmission for multiple-input multiple-output wireless systems C2 - 2002/// C3 - Conference Record of the Asilomar Conference on Signals, Systems and Computers DA - 2002/// VL - 1 SP - 531-535 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0037628394&partnerID=MN8TOARS ER - TY - CONF TI - On the design of optimal spreading sequences for CDMA systems C2 - 2002/// C3 - Conference Record of the Asilomar Conference on Signals, Systems and Computers DA - 2002/// VL - 2 SP - 1434-1438 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0037967846&partnerID=MN8TOARS ER - TY - JOUR TI - Capacity maximizing linear space-time codes T2 - IEICE Transactions on Electronics DA - 2002/// PY - 2002/// VL - E85-C IS - 3 SP - 428-435 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036504868&partnerID=MN8TOARS ER - TY - JOUR TI - Blind channel identification and equalization in OFDM-based multiantenna systems T2 - IEEE Transactions on Signal Processing AB - Wireless systems employing multiple antennas at the transmitter and the receiver have been shown to have the potential of achieving extraordinary bit rates. Orthogonal frequency division multiplexing (OFDM) significantly reduces the receiver complexity in multiantenna broadband systems. We introduce an algorithm for blind channel identification and equalization in OFDM-based multiantenna systems. Our approach uses second-order cyclostationary statistics, employs antenna precoding, and yields unique channel estimates (up to a phase rotation for each transmit antenna). Furthermore, it requires only an upper bound on the channel order, it does not impose restrictions on channel zeros, and it exhibits low sensitivity to stationary noise. We present simulation results demonstrating the channel estimator and the corresponding multichannel equalizer performance. DA - 2002/// PY - 2002/// DO - 10.1109/78.972486 VL - 50 IS - 1 SP - 96-109 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036173819&partnerID=MN8TOARS KW - blind equalization KW - cyclostationarity KW - MIMO KW - multiantenna systems KW - OFDM ER - TY - JOUR TI - Adaptive modulation and MIMO coding for broadband wireless data networks T2 - IEEE Communications Magazine AB - Link adaptation techniques, where the modulation, coding rate, and/or other signal transmission parameters are dynamically adapted to the changing channel conditions, have emerged as powerful tools for increasing the data rate and spectral efficiency of wireless data-centric networks. While there has been significant progress on understanding the theoretical aspects of time adaptation in LA protocols, new challenges surface when dynamic transmission techniques are employed in broadband wireless networks with multiple signaling dimensions. Those additional dimensions are mainly frequency, especially in multicarrier systems, and space in multiple-antenna systems, particularly multiarray multiple-input multiple-output communication systems. We give an overview of the challenges and promises of link adaptation in future broadband wireless networks. We suggest guidelines to help in the design of robust, complexity/cost-effective algorithms for these future wireless networks. DA - 2002/// PY - 2002/// DO - 10.1109/MCOM.2002.1007416 VL - 40 IS - 6 SP - 108-115 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036610014&partnerID=MN8TOARS ER - TY - CONF TI - On performance of the zero forcing receiver in presence of transmit correlation C2 - 2002/// C3 - IEEE International Symposium on Information Theory - Proceedings DA - 2002/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036350972&partnerID=MN8TOARS ER - TY - CONF TI - Multiple-input multiple-output wireless communication systems using antenna pattern diversity C2 - 2002/// C3 - Conference Record / IEEE Global Telecommunications Conference DA - 2002/// VL - 1 SP - 997-1001 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036969611&partnerID=MN8TOARS ER - TY - CONF TI - Link adaptation and channel prediction in wireless OFDM systems C2 - 2002/// C3 - Midwest Symposium on Circuits and Systems DA - 2002/// VL - 3 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036979356&partnerID=MN8TOARS ER - TY - JOUR TI - Linear dispersion codes for MIMO systems based on frame theory T2 - IEEE Transactions on Signal Processing AB - Multiple-input multiple-output (MIMO) wireless communication systems provide high capacity due to the plurality of modes available in the channel. Existing signaling techniques for MIMO systems have focused primarily on multiplexing for high data rate or diversity for high link reliability. In this paper, we present a new linear dispersion code design for MIMO Rayleigh fading channels. The proposed design bridges the gap between multiplexing and diversity and yields codes that typically perform well both in terms of ergodic capacity as well as error probability. This is important because, as we show, designs performing well from an ergodic capacity point of view do not necessarily perform well from an error probability point of view. Various techniques are presented for finding codes with good error probability performance. Monte Carlo simulations illustrate performance of some example code designs in terms of ergodic capacity, codeword error probability, and bit error probability. DA - 2002/// PY - 2002/// DO - 10.1109/TSP.2002.803325 VL - 50 IS - 10 SP - 2429-2441 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036794286&partnerID=MN8TOARS KW - diversity methods KW - MIMO systems KW - smart antennas KW - space-time codes ER - TY - JOUR TI - Modelling realistic electromagnetic effects on MIMO system capacity T2 - Electronics Letters AB - Computational electromagnetics is used to characterise the effect of realistic propagation on the capacity of multiple-input, multiple-output (MIMO) communication systems. Mutual information results for a MIMO system operating at 1.8 GHz in an urban micro-cellular environment are presented. DA - 2002/// PY - 2002/// DO - 10.1049/el:20021147 VL - 38 IS - 25 SP - 1624-1625 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0037028299&partnerID=MN8TOARS ER - TY - CONF TI - Equal gain transmission in multiple-input multiple-output wireless systems C2 - 2002/// C3 - Conference Record / IEEE Global Telecommunications Conference DA - 2002/// VL - 2 SP - 1124-1128 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036970266&partnerID=MN8TOARS ER - TY - CONF TI - An unequal error protection scheme for multiple input multiple output systems AU - Farooq Sabir, M. AU - Heath, R.W. AU - Bovik, A.C. C2 - 2002/// C3 - Conference Record of the Asilomar Conference on Signals, Systems and Computers DA - 2002/// VL - 1 SP - 575-579 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0037628345&partnerID=MN8TOARS ER - TY - CONF TI - Design and implementation of a series voltage sag compensator under practical utility conditions AU - Cheng, P.-T. AU - Huang, C.-C. AU - Pan, C.-C. AU - Bhattacharya, S. C2 - 2002/// C3 - Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC DA - 2002/// VL - 2 SP - 1061-1067 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036078253&partnerID=MN8TOARS ER - TY - CONF TI - Reliable adaptive modulation using long-range prediction at a different carrier frequency AU - Yang, Tung-Sheng AU - Duel-Hallen, A. AU - Hallen, H. AB - For fast vehicle speeds, reliable adaptive transmission requires prediction of future channel state information (CSI) since the channel conditions are rapidly time-variant. We propose to use past channel observations of one carrier to predict future CSI and perform adaptive modulation for another correlated carrier. A statistical model of the prediction error that depends on the frequency and time correlation is developed and is used in the design of reliable adaptive modulation methods. Significant gains relative to nonadaptive techniques are demonstrated for sufficiently correlated channels and realistic prediction range. Both Jakes (1974) fading model and a novel realistic physical model of frequency selective fading are used to validate performance of the proposed method. C2 - 2002/// C3 - Proceedings 2002 IEEE International Symposium on Information Theory (Cat. No.02CH37371) CY - Piscataway, NJ, USA DA - 2002/// DO - 10.1109/ISIT.2002.1023631 SP - 359 - UR - http://dx.doi.org/10.1109/ISIT.2002.1023631 ER - TY - CONF TI - Adaptive modulation using outdated samples of another fading channel AU - Yang, Tung-Sheng AU - Duel-Hallen, A. AB - Adaptive transmission techniques, such as adaptive modulation and coding, adaptive power control, adaptive transmitter antenna diversity, etc., generally require precise channel estimation and channel state information (CSI) feedback. For fast vehicle speeds, reliable adaptive transmission also requires prediction of future CSI since the channel conditions are rapidly time-variant. We propose to use past channel observations of one carrier to predict future CSI and perform adaptive modulation without feedback for another correlated carrier. A statistical model of the prediction error that depends on the frequency and time correlation is developed and is used in the design of reliable adaptive modulation methods. Significant gains relative to non-adaptive techniques are demonstrated for sufficiently correlated channels and realistic prediction range. C2 - 2002/// C3 - 2002 IEEE Wireless Communications and Networking Conference Record. WCNC 2002 (Cat. No.02TH8609) CY - Piscataway, NJ, USA DA - 2002/// DO - 10.1109/WCNC.2002.993542 VL - vol.1 SP - 477 - 81 UR - http://dx.doi.org/10.1109/WCNC.2002.993542 ER - TY - CONF TI - Adaptive modulation for transmitter antenna diversity mobile radio systems AU - Hu, Shengquan AU - Duel-Hallen, A. AU - Hallen, H. AB - Adaptive transmission techniques such as adaptive modulation and transmitter antenna diversity have been proposed for mobile wireless systems to satisfy high data-rate service requirements. In rapidly time variant channels, these methods need the knowledge of future fading conditions and therefore require accurate long range fading prediction. We investigate three combined adaptive modulation and transmitter diversity schemes in conjunction with our previously proposed long-range fading channel prediction (LRP) algorithm. It is demonstrated that the novel combined schemes achieve significantly higher data rates than conventional adaptive modulation methods when aided by the LRP. Performance-complexity trade-off for several combined adaptive methods is examined. In addition to utilizing the Jakes fading model to test the proposed methods, we validate the LRP for antenna diversity systems using a novel realistic fading channel model. C2 - 2002/// C3 - Proceedings 2002 IEEE International Symposium on Information Theory (Cat. No.02CH37371) CY - Piscataway, NJ, USA DA - 2002/// DO - 10.1109/ISIT.2002.1023377 SP - 105 - UR - http://dx.doi.org/10.1109/ISIT.2002.1023377 ER - TY - CONF TI - A physical model for wireless channels to provide insights for long range prediction AU - Hallen, H. AU - Duel-Hallen, A. AU - Hu, Shengquan AU - Yang, Tung-Shen AU - Lei, Ming C2 - 2002/// C3 - 2002 Military Communications Conference. Proceedings (Cat. No.02CH37397) CY - Piscataway, NJ, USA DA - 2002/// VL - vol.1 SP - 627 - 31 ER - TY - CONF TI - Raman tilt and nonideal tilt control function of C-band erbium-doped fiber amplifiers AU - Chen, Y. AU - Lunardi, L. AU - Al-Salameh, D. AU - Lumish, S. AB - Due to stimulated Raman scattering, shorter wavelength channels will pump longer wavelength channels, and so transfer their energy to longer wavelength channels. A tilt occurs when a flat DWDM signals travel through transmission fiber. We characterized the Raman tilt for 100 km SSMF and LEAF fiber at composite input powers ranging from 13 dBm to 22 dBm with a 40-channel laser source with 100 GHz spacing. Raman tilt with different fiber length at different composite launch power for SSMF is fully studied. In order to compensate the positive Raman gain tilt generated in the transmission fiber, a negative tilt is required. A tilt control function is available in some EDFAs. The mechanism of this tilt control is to use a tunable attenuator to change the internal loss of the amplifier. Unfortunately, the negatively tilted gain spectrum achieved by this mechanism is not a straight line. From the simulation result, the tilted gain curve actually can be regarded as two straight lines with a junction at about 1538 nm in good approximation. By combining the Raman output spectrum with the EDFA output spectrum, tilt is eliminated, but a non-flat spectral shape is generated with a dip at 1538 nm. This combined spectral shape agrees quite well with the measured spectral shape in actual system. This study reveals imperfection with this tilt compensation mechanism. A new tilt compensation solution is proposed and tested. Test results shown significant flatness improvement. C2 - 2002/8/23/ C3 - Optical Components and Transmission Systems DA - 2002/8/23/ DO - 10.1117/12.480569 VL - 4906 SP - 185-192 UR - http://dx.doi.org/10.1117/12.480569 KW - Erbium doped fiber amplifier KW - stimulated Raman scattering KW - WDM transmission KW - optical fiber ER - TY - JOUR TI - Advanced components and sub-system solutions for 40 Gb/s transmission AU - DeSalvo, R. AU - Wilson, A.G. AU - Rollman, J. AU - Schneider, D.F. AU - Lunardi, L.M. AU - Lumish, S. AU - Agrawal, N. AU - Steinbach, A.H. AU - Baun, W. AU - Wall, T. AU - Ben-Michael, R. AU - Itzler, M.A. AU - Fejzuli, A. AU - Chipman, R.A. AU - Kiehne, G.T. AU - Kissa, K.M. T2 - Journal of Lightwave Technology AB - With the commissioning of the latest 10-Gb/s systems, vendors are now in the process of developing architectures for their next-generation products. 40-Gb/s components and subsystems are currently in development to address the necessities of these next-generation systems. The top three challenges associated with 40-Gb/s transmission are optical signal-to-noise ratio, dispersion, and high-speed components. In order to realize 40-Gb/s transmission, new component and subsystem developments are crucial. This paper reviews the latest transmission technologies and dispersion compensation techniques developed to fulfill 40-Gb/s transmission system requirements. DA - 2002/12// PY - 2002/12// DO - 10.1109/jlt.2002.806782 VL - 20 IS - 12 SP - 2154-2181 UR - http://dx.doi.org/10.1109/jlt.2002.806782 KW - high speed KW - modulator KW - multiplexing KW - optical devices KW - optical fiber transmission KW - polarization-mode dispersion (PMD) emulator transponders KW - tunable dispersion compensator ER - TY - JOUR TI - Tunable dispersion compensation at 40-Gb/s using a multicavity etalon all-pass filter with NRZ, RZ, and CS-RZ modulation AU - Lunardi, L.M. AU - Moss, D.J. AU - Chandrasekhar, S. AU - Buhl, L.L. AU - Lamont, M. AU - McLaughlin, S. AU - Randall, G. AU - Colbourne, P. AU - Kiran, S. AU - Hulse, C.A. T2 - Journal of Lightwave Technology AB - We present a multichannel tunable dispersion compensator (TDC) based on multicavity all-pass etalons that is capable of operation at 40 Gb/s. The device has a tuning range of +200/-220 ps/nm with a group delay ripple < /spl plusmn/5 ps over a channel bandwidth of 80 GHz, an overall loss of < 5.2 dB, very low insertion loss ripple, and can operate on any channel on a 200-GHz grid over the C-band. In addition, we present system performance results at 40 Gb/s using NRZ, RZ, and CS-RZ modulation, compensating up to 45 km of nonzero dispersion shifted fiber (NZDSF). Our results show that this device introduces very little excess system penalty with signal frequency drifts of up to 20 GHz when operated near the center of its tuning range. For single channel experiments with fiber, the system penalty increase versus signal detuning is more significant, but can be reduced by dynamically optimizing the device dispersion during detuning. Finally, we demonstrate simultaneous compensation of 4 channels across the C-band over 25 km of NZDSF. DA - 2002/12// PY - 2002/12// DO - 10.1109/jlt.2002.806768 VL - 20 IS - 12 SP - 2136-2144 UR - http://dx.doi.org/10.1109/jlt.2002.806768 KW - chromatic dispersion KW - fiber optics communications KW - integrated optics devices KW - modulation formats ER - TY - CONF TI - Improved control of capacitor bank switching to minimize distribution systems losses AU - Coughlan, B.W. AU - Lubkeman, D.L. AU - Sutton, J. T2 - Twenty-Second Annual North American Power Symposium AB - The authors review the problem of controlling the switching of capacitor banks to minimize losses on distribution systems. A novel class of controls is available that allows capacitor switching to much more closely follow the actual loading on the distribution feeder. This allows for much better control of reactive loading throughout the distribution system, reduced line losses, improved voltage regulation, and reduced facility loading. The operating characteristics and performance of several of the controls are reviewed and compared. To effectively use the controls, distribution systems engineers must have a methodology to determine appropriate switching set points. The development of an appropriate methodology and its implementation in the form of a computer program called VDXTCAP are described.< > C2 - 2002/12/4/ C3 - Proceedings of the Twenty-Second Annual North American Power Symposium DA - 2002/12/4/ DO - 10.1109/naps.1990.151388 PB - IEEE Comput. Soc. Press SN - 081862115X UR - http://dx.doi.org/10.1109/naps.1990.151388 DB - Crossref ER - TY - JOUR TI - Turbo multiuser detection for coded DMT VDSL systems AU - Dai, H. AU - Poor, V. T2 - IEEE Journal on Selected Areas in Communications AB - In recent years, iterative processing techniques with soft-in/soft-out components have received considerable attention. Such techniques, based on the so-called turbo principle, are exemplified through turbo decoding, turbo equalization, and turbo multiuser detection. Turbo multiuser detection is applied to a discrete multitone (DMT) very-high-rate digital subscriber line system to combat crosstalk signals and to obtain substantial coding gain. The proposed iterative DMT receiver is shown to achieve an overall 7.0 dB gain over the uncoded optimum receiver at a bit error rate of 10/sup -7/ for a channel with severe intersymbol interference and additive white Gaussian noise and with one dominant crosstalk signal. Impulse noise is detrimental to the proposed scheme but can be overcome through erasure decoding techniques, as is shown by example. DA - 2002/// PY - 2002/// DO - 10.1109/49.983354 VL - 20 IS - 2 SP - 351-362 J2 - IEEE J. Select. Areas Commun. OP - SN - 0733-8716 UR - http://dx.doi.org/10.1109/49.983354 DB - Crossref KW - coded discrete multitone KW - crosstalk KW - gray coding KW - impulse noise KW - multiuser detection KW - turbo decoding KW - very-high-rate digital subscriber line ER - TY - JOUR TI - Iterative space-time processing for multiuser detection in multipath CDMA channels AU - Dai, Huaiyu AU - Poor, H.V. T2 - IEEE Transactions on Signal Processing AB - Space-time processing and multiuser detection are two promising techniques for combating multipath distortion and multiple-access interference in code division multiple access (CDMA) systems. To overcome the computational burden that rises very quickly with increasing numbers of users and receive antennas in applying such techniques, iterative implementations of several space-time multiuser detection algorithms are considered here. These algorithms include iterative linear space-time multiuser detection, Cholesky iterative decorrelating decision-feedback space-time multiuser detection, multistage interference canceling space-time multiuser detection, and expectation-maximization (EM)-based iterative space-time multiuser detection. A new space-time multiuser receiver structure that allows for efficient implementation of iterative processing is also introduced. Fully exploiting various types of diversity through joint space-time processing and multiuser detection brings substantial gain over single-receiver-antenna or single-user-based methods. It is shown that iterative implementation of linear and nonlinear space-time multiuser detection schemes discussed in this paper realizes this substantial gain and approaches the optimum performance with reasonable complexity. Among the iterative space-time multiuser receivers considered in this paper, the EM-based (SAGE) iterative space-time multiuser receiver introduced here achieves the best performance with excellent convergence properties. DA - 2002/9// PY - 2002/9// DO - 10.1109/tsp.2002.801923 VL - 50 IS - 9 SP - 2116-2127 J2 - IEEE Trans. Signal Process. LA - en OP - SN - 1053-587X UR - http://dx.doi.org/10.1109/tsp.2002.801923 DB - Crossref KW - antenna arrays KW - CDMA KW - iterative processing KW - multiuser detection KW - SAGE KW - space-time processing ER - TY - CONF TI - Generator Bidding Strategies in a Competitive Deregulated Market Accounting for Availability and Bid Segments AU - Lu, N. AU - Chow, J.H. AU - Desrochers, A.A. C2 - 2002/// C3 - Proc. of VIII Symposium of Specialists in Electric Operational and Expansion Planning CY - Brasilia, Brazil DA - 2002/// ER - TY - CONF TI - Network Processor Design for Optical Burst Switched Networks AU - Mehrotra, P. AU - Baldine, I. AU - Stevenson, D. AU - Franzon, P. T2 - 14th Annual IEEE International ASIC/SOC Conference AB - Scalable hardware, architectures are required for optical burst switched (OBS) networks where future fibers may be handling 4Tbps or more. Issues investigated include centralized vs. distributed architectures, sealing issues related to performance, and the hardware impact of just-in-time (JIT) vs. just-enough-time (JET) signaling. C2 - 2002/// C3 - Proceedings of the 14th Annual IEEE International ASIC/SOC Conference CY - Arlington, VA, USA DA - 2002/// PY - 2001/9/12/ DO - 10.1109/ASIC.2001.954715 SP - 296–300 PB - IEEE SN - 0-7803-6741-3 ER - TY - CONF TI - Novel Hardware Implementation for Fast Address Lookups AU - Mehortra, P. AU - Franzon, P. T2 - 2002 Workshop on High Performance Switching and Routing AB - The most time critical part in packet forwarding is the route lookup which determines the next hop address of the packet. The problem of searching for routes in large databases is compounded by the fact that routing tables store variable length prefixes and their corresponding next hop addresses. In order to forward a packet, routers need to find the longest matching prefix for the destination address. The work presented describes a new fast and efficient algorithm for searching a large database. The scheme described requires several accesses to a small, fast on-chip SRAM and only one access to a slower DRAM in order to determine the next hop address. The paper discusses some of the related work and approaches in performing route lookups. It describes the proposed algorithm where only a single off-chip DRAM access is required to determine the next hop address. It discusses some of the details of the hardware implementation and lists some of the results of the scheme. Some of the design issues are also discussed. C2 - 2002/// C3 - Proceedings of 2002 Workshop on High Performance Switching and Routing CY - Kobe, Japan DA - 2002/// PY - 2002/5/26/ DO - 10.1109/HPSR.2002.1024217 PB - IEEE SN - 4-88552-184-X ER - TY - CONF TI - 4 Gbps AC Coupled Interconnection AU - Mick, S.E. AU - Wilson, J.M. AU - Franzon, P. T2 - IEEE 2002 Custom Integrated Circuits Conference AB - AC coupled interconnects enable multi-gigabit-persecond communication data rates between integrated circuits with very high pin counts and low power consumption. AC coupling can be realized with either series capacitive or inductive coupling elements. Capacitive AC coupling offers better performance when low power I/O buffers are required and when there is sufficient area to dedicate to coupling capacitors in the top-level metal of each IC. At a slight expense of circuit complexity, inductive AC coupling can be used to bring I/O pad pitches down to 75 /spl mu/m and maintain a controlled impedance connection. A novel physical structure, buried solder bumps, are used as a solution for providing DC power and ground connections across the same surface as the AC connections. When used in conjunction with NRZ-tolerant receivers, and current-mode signaling, highly effective interconnect structures can be built. As well as presenting both physical and circuit aspects of this work, experimental results are shown. C2 - 2002/// C3 - Proceedings of the IEEE Custom Integrated Circuits Conference CY - Orlando, FL, USA DA - 2002/// PY - 2002/5/12/ DO - 10.1109/CICC.2002.1012783 SP - 133–140 PB - IEEE SN - 0-7803-7250-6 ER - TY - CONF TI - Binary Search Schemes for Fast IP Lookups AU - Mehortra, P. AU - Franzon, P. T2 - Global Telecommunications Conference, 2002 AB - Route lookup is becoming a very challenging problem due to the increasing size of routing tables. To determine the outgoing port for a given address, the longest matching prefix among all the prefixes, needs to be determined. This makes the task of searching in a large database quite difficult. Our paper describes binary search schemes that allow fast address lookups. Binary search can be performed on the number of entries or on the number of mutually disjoint prefixes. Lookups can be performed in O(N) time, where N is number of entries and the amount of memory required to store the binary database is also O(N). These schemes scale very well with both large databases and for longer addresses (as in IPv6). C2 - 2002/11/17/ C3 - Proceedings of the IEEE Globecom CY - Taipei, Taiwan DA - 2002/11/17/ PY - 2002/11/17/ DO - 10.1109/GLOCOM.2002.1188551 SP - 2005–2009 PB - IEEE SN - 0-7803-7632-3 ER - TY - CONF TI - Buried solder bump connections for high- density capacitive coupling AU - Mick, S. AU - Luo, L. AU - Wilson, J. AU - Franzon, P. T2 - 2002 IEEE 11th Topical Meeting on Electrical Performance of Electronic Packaging AB - AC coupled interconnects enable reliable, multi-gigabit-per-second communication data rates between integrated circuits with very high pin counts and low power consumption. When used in conjunction with NRZ-tolerant receivers, interconnect arrays with pitches below 100 /spl mu/m and data rates of 6 Gbps/per pin can be built. C2 - 2002/10/21/ C3 - Proceedings of the IEEE Electrical Performance of Electronic Packaging CY - Monterey, CA, USA DA - 2002/10/21/ PY - 2002/10/21/ DO - 10.1109/EPEP.2002.1057916 SP - 205–208 PB - IEEE SN - 0-7803-7451-7 ER - TY - CONF TI - Low power logical element for FPGA fabric AU - Nakkar, M. AU - Franzon, P. T2 - The 14th International Conference on Microelectronics AB - Logical Element (LE) is the basic building block of FPGA fabric or any re-configurable computing machines. Logical Element basically consists of look-up tables according to A.B. Smith et al. (2000). This paper shows a low power LE. The low power is achieved by taking advantage of the commutative property of operations. This property will allow the data to be reorganized such that there will be separate paths for logic state 0 and logic state 1. The approach is targeted to reduce switching activity when possible. This paper shows 28% increase in power savings. C2 - 2002/12/13/ C3 - Proceedings of the IEEE International Conference on Microelectronics CY - Beirut, Lebanon DA - 2002/12/13/ PY - 2002/12/13/ DO - 10.1109/ICM-02.2002.1161495 SP - 55–57 PB - IEEE SN - 0-7803-7573-4 ER - TY - CONF TI - A multichannel, pipeline analog-to- digital converter for an integrated 3-D ultrasound imaging system AU - Kaviani, K. AU - Oralkan, Ö. AU - Khuri-Yakub, B.T. AU - Wooley, B.A. C2 - 2002/// C3 - Proceedings of the European SolidState Circuits Conference (ESSCIRC) DA - 2002/// SP - 263–266 ER - TY - CONF TI - Scalable Molecular Circuit Architectures AU - Franzon, P. AU - Amsinck, C.J. AU - Nackashi, D.P. AU - DeSpagna, N. C2 - 2002/12// C3 - 2002 Engineering Foundation Conference on Molecular Computing CY - Key West DA - 2002/12// ER - TY - CONF TI - Packaging Technology for AC Coupled Interconnection AU - Mick, S. AU - Franzon, P. AU - Huffman, A. C2 - 2002/7// C3 - IMAPS Flip-Chip Conference DA - 2002/7// ER - TY - CONF TI - Design of all-pole low-pass ladder filters using current-mode damped integrators AU - Oralkan, O. AU - Ilker Karsilayan, A. AU - Ali Tan, M. T2 - 1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96 AB - A method for operational simulation of all-pole low-pass LC ladders filters by using current-mode damped integrators is introduced. The circuits obtained by this method need only current mirrors and capacitors and are convenient for realization in CMOS technology as well as can be used in other technologies. C2 - 2002/12/24/ C3 - 1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96 DA - 2002/12/24/ DO - 10.1109/iscas.1996.539880 PB - IEEE SN - 0780330730 UR - http://dx.doi.org/10.1109/iscas.1996.539880 DB - Crossref ER - TY - CONF TI - Differentiation between electric breakdowns and dielectric breakdown in thin silicon oxides AU - Jackson, J.C. AU - Robinson, T. AU - Oralkan, O. AU - Dumin, D.J. AU - Brown, G.A. T2 - 1997 6th International Symposium on the Physical and Failure Analysis of Integrated Circuits AB - It has been known for some time that non-destructive electric breakdowns precede destructive thermal dielectric breakdown. We have been studying both processes in oxides between 5 nm and 80 nm in thickness. We have shown that the electric breakdowns can trigger dielectric breakdown under certain conditions. This triggering of dielectric breakdown causes TDDB distributions to be non-unique. The TDDB distributions could be shifted to shorter times if (a) the impedance of the test equipment was lowered and/or (b) the capacitance of the test equipment was raised. The implications of this work are discussed in terms of electric/dielectric breakdown models and practical circuit and device operation. C2 - 2002/11/23/ C3 - Proceedings of the 1997 6th International Symposium on the Physical and Failure Analysis of Integrated Circuits DA - 2002/11/23/ DO - 10.1109/ipfa.1997.638180 PB - IEEE SN - 0780339851 UR - http://dx.doi.org/10.1109/ipfa.1997.638180 DB - Crossref ER - TY - CONF TI - The non-uniqueness of breakdown distributions in silicon oxides AU - Jackson, J.C. AU - Oralkan, O. AU - Robinson, T. AU - Dumin, D.J. AU - Brown, G.A. T2 - 1997 IEEE International Integrated Reliability Workshop Final Report AB - Time-dependent-dielectric-breakdown (TDDB) distributions obtained from oxides of the same physical geometry and stressed at the same electric field were found to shift to shorter times when the amount of energy available to flow through electric breakdowns was increased. This paper shows that TDDB distributions are nonunique and that for a breakdown model to accurately describe the reliability of an oxide during actual use conditions, the oxide thermal geometry must be taken into account. An accurate method of obtaining electric breakdown distributions is also presented which allows the use of smaller sample sizes to obtain time-dependent-electric-breakdown (TDEB) distributions which are similar to TDDB distributions. C2 - 2002/11/23/ C3 - 1997 IEEE International Integrated Reliability Workshop Final Report (Cat. No.97TH8319) DA - 2002/11/23/ DO - 10.1109/irws.1997.661871 PB - IEEE SN - 0780342054 UR - http://dx.doi.org/10.1109/irws.1997.661871 DB - Crossref ER - TY - CONF TI - Capacitive micromachined ultrasonic transducer arrays for medical imaging: experimental results AU - Denmirci, U. AU - Oralkan, O. AU - Johnson, J.A. AU - Ergun, A.S. AU - Karaman, M. AU - Khuri-Yakub, B.T. T2 - 2001 IEEE Ultrasonics Symposium. Proceedings. An International Symposium AB - Capacitive micromachined ultrasonic transducer (cMUT) arrays provide broad bandwidth, high sensitivity, low mechanical impedance, and potential for electronic integration, and thus are promising for medical imaging applications. We have designed and fabricated 1D and 2D MUT arrays of various sizes using standard integrated circuit fabrication processes. We improved the device parameters for medical imaging applications to achieve fully functional 64- and 128-element linear 1D cMUT arrays. We have also built a computer controlled experimental setup for collecting pulse-echo data from the test phantoms using MUT arrays. In this paper the design and optimization of the immersion cMUTs for medical imaging system are discussed, and the phased array B-scan sector images taken by 1D MUT arrays are presented. C2 - 2002/11/14/ C3 - 2001 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.01CH37263) DA - 2002/11/14/ DO - 10.1109/ultsym.2001.991878 PB - IEEE SN - 0780371771 UR - http://dx.doi.org/10.1109/ultsym.2001.991878 DB - Crossref ER - TY - CONF TI - Assessment of animal odors: comparison of electronic nose and human panel AU - Schiffman, S.S. AU - Graham, B.G. AU - Gutierrez-Osuna, R. AU - Zervakis, J. AU - Nagle, H.T. T2 - ISOEN’02 A2 - D’Amico, A. A2 - Di Natale, C. C2 - 2002/// C3 - Ninth International Symposium on Olfaction and the Electronic Nose DA - 2002/// PY - 2002/// SP - 224–225 PB - Aracne ER - TY - CONF TI - Measuring odor intensity with photoionization detector (PID) AU - Schiffman, S.S. AU - Graham, B.G. AU - Nagle, H.T. T2 - ISOEN’02 C2 - 2002/// C3 - Ninth International Symposium on Olfaction and the Electronic Nose DA - 2002/// ER - TY - CONF TI - Defect tolerant implementations of feed-forward and recurrent neural networks AU - Franzon, P. AU - van den Bout, D. AU - Paulos, J. AU - Miller, T. AU - Snyder, W. AU - Nagle, T. AU - Liu, Wentai T2 - International Conference on Wafer Scale Integration AB - Many of the defect tolerant techniques employed to achieve wafer-scale integration can also be used to construct flexible and scalable architectures. These techniques are applied to two artificial neural networks: a feed-forward analog network with backpropagation and an efficient digital recurrent network.< > C2 - 2002/12/4/ C3 - 1990 Proceedings. International Conference on Wafer Scale Integration DA - 2002/12/4/ DO - 10.1109/icwsi.1990.63897 PB - IEEE Comput. Soc. Press SN - 0818690135 UR - http://dx.doi.org/10.1109/icwsi.1990.63897 DB - Crossref ER - TY - CONF TI - Microelectrode arrays: structures and applications AU - Nagle, H.T. AU - Ash, R.B. T2 - 1990 IEEE Colloquium in South America AB - The rapidly advancing technology of microelectronics is being employed by several research groups to develop microelectrode arrays for use in life science research. The authors review the development of microelectrodes using silicon-based technology over the last decade. Silicon-based technology is applied to micromachine structures that are used as substrates for electrode arrays. The resulting microelectrodes are now being utilized in cardiac and neural mapping applications at Duke University Medical Center. Specific applications in the electrophysiology of taste and smell are presented.< > C2 - 2002/12/4/ C3 - Proceedings of the 1990 IEEE Colloquium in South America DA - 2002/12/4/ DO - 10.1109/colloq.1990.152788 PB - IEEE SN - 0879426101 UR - http://dx.doi.org/10.1109/colloq.1990.152788 DB - Crossref ER - TY - CONF TI - QRS/BIST: a reliable heart rate monitor ASIC AU - Roy, S.C. AU - Nagle, H.T. AU - McNamer, M.G. AU - Krakow, W.T. T2 - Third Annual IEEE on ASIC Seminar and Exhibit AB - The design of a real-time heart rate monitor implemented as a single application-specific integrated circuit (ASIC) is presented. The goal of the project was to implement a QRS detection algorithm into a single-chip environment. The testability strategies used to increase device reliability, including the implementation of built-in-self test (BIST) features, are described.< > C2 - 2002/12/4/ C3 - Third Annual IEEE Proceedings on ASIC Seminar and Exhibit DA - 2002/12/4/ DO - 10.1109/asic.1990.186186 PB - IEEE UR - http://dx.doi.org/10.1109/asic.1990.186186 DB - Crossref ER - TY - CONF TI - Dynamic power supply current monitoring of SRAMs AU - Su, Shyang-Tai AU - Makki, R.Z. AU - Nagle, H.T. AU - Liu, Jian T2 - Seventh Annual IEEE International ASIC Conference and Exhibit AB - In this paper, we report the results of a physical experiment aimed at assessing a new test method for CMOS SRAMs. The test method involves a new and simple philosophy for testing: monitor the switching behavior of a circuit rather than just the output logic state. Observing the dynamic (transient) power supply current can lead to drastic improvement in "real" defect coverage. We use the dynamic power supply current as indicative of such switching.< > C2 - 2002/12/17/ C3 - Proceedings Seventh Annual IEEE International ASIC Conference and Exhibit DA - 2002/12/17/ DO - 10.1109/asic.1994.404538 PB - IEEE SN - 0780320204 UR - http://dx.doi.org/10.1109/asic.1994.404538 DB - Crossref ER - TY - CONF TI - Controlling electrical side effects of cardiac stimulus pulses due to high impedance electrodes AU - Andrews, C.A. AU - Kermani, B.G. AU - Cascio, W.E. AU - Nagle, H.T. T2 - 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society AB - A method of measuring the extracellular voltage field in working cardiac tissue with high impedance sensors immediately after a superthreshold stimulation pulse has been developed. Previously, the stimulus pulse charged the input circuitry of the front-end amplifier with an amplitude much greater than the biological signal desired. To address this problem a blanking period was introduced which disables the amplifiers for the duration of the superthreshold stimulus pulse. As a result of this process, electrical activity can be measured almost immediately after the superthreshold stimulus pulse without distortion.< > C2 - 2002/12/17/ C3 - Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society DA - 2002/12/17/ DO - 10.1109/iembs.1994.415233 PB - IEEE SN - 0780320506 UR - http://dx.doi.org/10.1109/iembs.1994.415233 DB - Crossref ER - TY - CONF TI - Application of surface mount technology for biomedical microsensor interconnections AU - Mundt, C. AU - Ash, B. AU - Ufer, S. AU - Buck, R.P. AU - Nagle, H.T. T2 - 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society AB - A method of connecting flexible electrode arrays to a flat cable or a flexible circuit is described. Solderpaste printing and reflow soldering techniques (as used in surface mount technology) are used to make a solder connection between a fine pitch flat cable and the bondpads on an electrode array. An epoxy and silicone encapsulation is added to achieve reliable connections for cardiovascular applications.< > C2 - 2002/12/17/ C3 - Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society DA - 2002/12/17/ DO - 10.1109/iembs.1994.415153 PB - IEEE SN - 0780320506 UR - http://dx.doi.org/10.1109/iembs.1994.415153 DB - Crossref ER - TY - CONF TI - A new method in obtaining a better generalization in artificial neural networks AU - Kermani, B.G. AU - White, M.W. AU - Nagle, H.T. T2 - 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society AB - Overtraining is a serious problem in the neural network algorithms, including the backpropagation algorithm. In order to measure the performance of a neural network, ordinarily some of the data is sacrificed and used as a test set (cross-validation method). When the data is very scarce or is expensive, e.g. medical applications such as computer aided diagnosis, this waste of the data becomes intolerable. A new technique is introduced which uses the shape of the training mean squared error graph versus number of epochs and predicts when is the best time (epoch number) to discontinue the training. C2 - 2002/12/17/ C3 - Proceedings of 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society DA - 2002/12/17/ DO - 10.1109/iembs.1994.415352 PB - IEEE SN - 0780320506 UR - http://dx.doi.org/10.1109/iembs.1994.415352 DB - Crossref ER - TY - CONF TI - Feature extraction by genetic algorithms for neural networks in breast cancer classification AU - Kermani, B.G. AU - White, M.W. AU - Nagle, H.T. T2 - 17th International Conference of the Engineering in Medicine and Biology Society AB - In today's world, in which computerized recognition is expanding its horizons in the field of medicine, breast cancer classification is receiving wide attention. In this application, artificial neural networks have achieved reasonable recognition rates. However, to improve performance, a technique is needed to screen the features of the input data, to extract the important ones and suppress those that are irrelevant. Although neural networks do have this capability to some extent, here it is shown that by using a hybrid genetic algorithm and neural network (GANN), the feature extraction can be performed more effectively. Another advantage of augmenting NN training with a GA is that the extracted features using GA are explicit and perceivable. Although the authors evaluated the technique using breast cancer data, the methodology is designed to handle any other kind of classification task. C2 - 2002/11/19/ C3 - Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society DA - 2002/11/19/ DO - 10.1109/iembs.1995.575385 PB - IEEE SN - 0780324757 UR - http://dx.doi.org/10.1109/iembs.1995.575385 DB - Crossref ER - TY - CONF TI - Transient power supply current testing of digital CMOS circuits AU - Makki, R.Z. AU - Su, Shyang-Tai AU - Nagle, T. T2 - 1995 IEEE International Test Conference (ITC) AB - This paper presents, in a tutorial fashion, a test technique that employs the transient power supply current, i/sub DDT/, as a window of observability into the switching behaviour of an integrated circuit. The premise is that when a circuit switches states, a temporary path is established between power and ground which results in a transient current. With proper power tree distribution, observing this transient current provides direct insight into the switching pattern of a circuit under a given stimulus. This paper includes an overall summary of physical experiments that have been conducted (previously reported in parts) as well as new results on the test overhead. The physical experimental results show i/sub DDT/ to be effective in detecting disturb faults in SRAMs and drain/ source opens in general CMOS logic structures. C2 - 2002/11/19/ C3 - Proceedings of 1995 IEEE International Test Conference (ITC) DA - 2002/11/19/ DO - 10.1109/test.1995.529922 PB - Int. Test Conference SN - 0780329929 UR - http://dx.doi.org/10.1109/test.1995.529922 DB - Crossref ER - TY - CONF TI - Transmission line models for ion-selective membranes in cardiology simulated with SPICE AU - Mundt, C. AU - Nagle, H.T. AU - Buck, R.P. T2 - 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society AB - Ion-selective membranes are a key component of cardiovascular micro-electrodes used to study ischemic events in vivo. This paper presents and compares two circuit models for charged species transport by diffusion in ion-selective membranes. One is a conventional, finite transmission line with resistors in series along the line and capacitors running crosswise to ground. The other circuit is the BBB (Barkel-Brumleve-Buck) circuit. The similarities and differences of these circuits are discussed and the impedance functions are compared. For both circuits discretized SPICE models were developed to verify the impedance functions and to investigate the behavior of the circuits for a variety of component values. The comparison showed that the BBB circuit can provide a more general model than the conventional transmission line. However, in many cases the two circuits can be converted into each other. The corresponding relations between the component values were derived. C2 - 2002/12/24/ C3 - Proceedings of 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society DA - 2002/12/24/ DO - 10.1109/iembs.1996.646310 PB - IEEE SN - 0780338111 UR - http://dx.doi.org/10.1109/iembs.1996.646310 DB - Crossref ER - TY - CONF TI - On-line control of propagating cardiac wavefronts AU - Goode, P.V. AU - Nagle, H.T. T2 - 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society AB - A technique for on-line control of a propagating cardiac wavefront is presented. This technique uses low-level inhibitory stimuli to hyperpolarize segments of the cardiac tissue. The stimuli can delay conduction of a propagating wavefront as well as change its propagation direction. The bidomain model is used to simulate these phenomena assuming a thin sheet of cardiac tissue. C2 - 2002/12/24/ C3 - Proceedings of 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society DA - 2002/12/24/ DO - 10.1109/iembs.1996.646510 PB - IEEE SN - 0780338111 UR - http://dx.doi.org/10.1109/iembs.1996.646510 DB - Crossref ER - TY - CONF TI - Hierarchical simulation of high speed digital interconnects using a packaging simulator AU - Basel, M.S. AU - Steer, M.B. AU - Franzon, P.D. T2 - 1994 Proceedings. 44th Electronic Components and Technology Conference AB - A hierarchical strategy is presented which permits the tradeoff of modeling and simulation accuracy with simulation speed in the simulation of high speed signals on interconnects in multichip modules and printed circuit boards. Using a point modeling paradigm for discontinuities and impulse response thresholding a smooth transition is achieved between delay modeling and full circuit simulation.< > C2 - 2002/12/17/ C3 - 1994 Proceedings. 44th Electronic Components and Technology Conference DA - 2002/12/17/ DO - 10.1109/ectc.1994.367647 PB - IEEE SN - 0780309146 UR - http://dx.doi.org/10.1109/ectc.1994.367647 DB - Crossref ER - TY - JOUR TI - Multiple Working Points in Multichannel ALOHA with Deadlines AU - Baron, D. AU - Birk, Y. T2 - Wireless Networks DA - 2002/1// PY - 2002/1// VL - 8 IS - 1 SP - 5–11 ER - TY - CONF TI - 4 GHz and 13 GHz tuned amplifiers implemented in a 0.1 μm CMOS technology on SOI and SOS substrates AU - Kim, K.-H. AU - Ho, Y.-C. AU - Floyd, B. AU - Wann, C. AU - Taur, Y. AU - Lagnado, I. T2 - 1998 IEEE International Solid-State Circuits Conference. Digest of Technical Papers. ISSCC AB - CMOS is a viable contender for front-end receiver circuits in the frequency range between 0.9 and 2 GHz. As gate lengths decrease to 0.1 /spl mu/m and below, this frequency range will increase, potentially opening up applications such as wireless LANs in the 5-20 GHz range. These 4 GHz and 13 GHz CMOS tuned amplifiers are implemented with partially-depleted silicon on insulator (SOI) and silicon on sapphire (SOS) nMOS transistors with floating bodies. Measured forward gains (S21) for the 4 GHz SOS and SOI amplifiers are 12 and 11 dB, respectively, and 15 and 5.3 dB for the 13 GHz SOS and SOI amplifiers. The 13 GHz amplifiers are the first in a CMOS technology to have tuned frequencies greater than 10 GHz. The CMOS process uses 0.35 /spl mu/m design rules for all dimensions except for the 0.1 /spl mu/m gate length and 2.9 nm gate oxide thickness. The nMOS transistors have -100 GHz measured peak f/sub T/. Threshold voltages are 0.2 and 0.4 V for the SOS and SOI transistors, respectively. C2 - 2002/11/27/ C3 - 1998 IEEE International Solid-State Circuits Conference. Digest of Technical Papers, ISSCC. First Edition (Cat. No.98CH36156) DA - 2002/11/27/ DO - 10.1109/isscc.1998.672405 PB - IEEE SN - 0780343441 UR - http://dx.doi.org/10.1109/isscc.1998.672405 DB - Crossref ER - TY - CONF TI - Wireless interconnection in a CMOS IC with integrated antennas AU - Floyd, B. AU - Kim, K. AU - Kenneth, O. T2 - 2000 IEEE International Solid-State Circuits Conference. Digest of Technical Papers AB - Improved RF capability and projected increase in die size for CMOS circuits lead to the concept of wireless communications within and between chips. A potential application is wireless clock distribution, proposed as an alternative interconnect system capable of distributing high frequency clock signals at the speed of light using microwaves. The wireless clock distribution system consists of a clock transmitter, located on or off chip, broadcasting a microwave global clock signal at frequencies greater than 15 GHz, and a grid of integrated clock receivers. The global clock signal is received using an integrated dipole antenna. The signal is then amplified using a low-noise amplifier (LNA), frequency divided down to the local clock frequency, buffered, and distributed to provide local clock signals. This IC operating at 7.4 GHz, which integrates antennas and necessary receiver circuits in 0.25 /spl mu/m CMOS with five metal layers on p-substrates, is a first step towards realizing such a system. C2 - 2002/11/7/ C3 - 2000 IEEE International Solid-State Circuits Conference. Digest of Technical Papers (Cat. No.00CH37056) DA - 2002/11/7/ DO - 10.1109/isscc.2000.839802 PB - IEEE SN - 0780358538 UR - http://dx.doi.org/10.1109/isscc.2000.839802 DB - Crossref ER - TY - CONF TI - Estimation of the signal-to-noise ratio for on-chip wireless clock signal distribution (year 2000) AU - Bravo, D. AU - Yoon, Hyun AU - Kim, Kihong AU - Floyd, B. AU - O, K.K. T2 - IEEE 2000 International Interconnect Technology Conference AB - The achievable signal-to-noise ratio for an 18-GHz wireless clock distribution system has been estimated by extrapolating from the current status of the clock receiver, the integrated antenna performance, and the understanding of noise sources and coupling mechanisms. It is estimated that a SNR of /spl sim/23 dB is achievable at the input of the frequency divider within the clock receiver block. C2 - 2002/11/7/ C3 - Proceedings of the IEEE 2000 International Interconnect Technology Conference (Cat. No.00EX407) DA - 2002/11/7/ DO - 10.1109/iitc.2000.854082 PB - IEEE SN - 0780363272 UR - http://dx.doi.org/10.1109/iitc.2000.854082 DB - Crossref ER - TY - CONF TI - The effects of substrate resistivity on RF component and circuit performance AU - Floyd, B.A. AU - Hung, Chih-Ming AU - O, K.K. T2 - IEEE 2000 International Interconnect Technology Conference AB - The benefits of using high-resistivity substrates for RF CMOS applications are experimentally quantified. The quality factors of spiral inductors with a patterned ground shield, varactors, and transistors have been measured on both p/sup +/ (with epi) and p/sup -/ substrates, and in each case, Q is higher on p/sup $/substrates. A 5.35-GHz VCO on a p-substrate has an 8 dB lower phase noise than that on a p/sup +/ substrate, while a 7-GHz LNA on a p/sup -/ substrate has a 6 dB higher gain and /spl sim/2.5 dB lower noise figure than that on a p/sup +/ substrate. C2 - 2002/11/7/ C3 - Proceedings of the IEEE 2000 International Interconnect Technology Conference (Cat. No.00EX407) DA - 2002/11/7/ DO - 10.1109/iitc.2000.854313 PB - IEEE SN - 0780363272 UR - http://dx.doi.org/10.1109/iitc.2000.854313 DB - Crossref ER - TY - CONF TI - A fully integrated 5.35-GHz CMOS VCO and a prescaler AU - Hung, Chih-Ming AU - Floyd, B.A. AU - O, K.K. T2 - 2000 IEEE Radio Frequency Integrated Circuits (RFIC) Symposium. Digest of Papers AB - A 5.35-GHz monolithic VCO and a prescaler have been fabricated in a 0.25-/spl mu/m CMOS process. The VCO has a tuning range of 336 MHz and phase noise of -117 dBc/Hz at a 1-MHz offset and 7-mW power consumption. The low phase noise is achieved by using only PMOS transistors in the VCO core and by optimizing the resonator layout. The prescaler utilizes a variation of the source coupled logic and consumes only 4.1 mW at VDD=1.5 V and 5.4 GHz. A second prescaler operating at 9.96 GHz and 2.5-V VDD is also demonstrated. C2 - 2002/11/7/ C3 - 2000 IEEE Radio Frequency Integrated Circuits (RFIC) Symposium Digest of Papers (Cat. No.00CH37096) DA - 2002/11/7/ DO - 10.1109/rfic.2000.854419 PB - IEEE SN - 0780362802 UR - http://dx.doi.org/10.1109/rfic.2000.854419 DB - Crossref ER - TY - CONF TI - A 15-GHz wireless interconnect implemented in a 0.18-μm CMOS technology using integrated transmitters, receivers, and antennas AU - Floyd, B.A. AU - Hung, Chih-Ming AU - Kenneth, K.O. T2 - 2001 Symposium on VLSI Circuits. Digest of Technical Papers AB - Using a 6-metal, copper 0.18-/spl mu/m CMOS technology, a 15-GHz on-chip wireless interconnect system has been demonstrated. The transmission frequency and distance (5.6 mm) of on-chip wireless interconnection have been almost doubled compared to the previously reported system. In addition, an integrated transmitter for on-chip wireless interconnection has been demonstrated. Lastly, the RF potential of CMOS technology for >10 GHz is assessed. C2 - 2002/11/13/ C3 - 2001 Symposium on VLSI Circuits. Digest of Technical Papers (IEEE Cat. No.01CH37185) DA - 2002/11/13/ DO - 10.1109/vlsic.2001.934225 PB - Japan Soc. Appl. Phys SN - 4891140143 UR - http://dx.doi.org/10.1109/vlsic.2001.934225 DB - Crossref ER - TY - CONF TI - Design of a key agile cryptographic system for OC-12c rate ATM AU - Stevenson, D. AU - Hillery, N. AU - Byrd, G. AU - Gong, Fengmin AU - Winkelstein, D. T2 - Symposium on Network and Distributed System Security AB - The paper describes an experimental key agile cryptographic system under design at MCNC. The system is compatible with ATM local- and wide-area networks. The system establishes and manages secure connections between hosts in a manner which is transparent to the end users and compatible with existing public network standards. A Cryptographic Unit supports hardware encryption and decryption at the ATM protocol layer. The system is SONET compatible and operates full duplex at the OC-12c rate (622 Mbps). Separate encryption keys are negotiated for each secure connection. Each Cryptographic Unit can manage more than 65,000 active secure connections. The Cryptographic Unit can be connected either in a security gateway mode referred to as a 'bump-in-the-fiber' or as a direct ATM host interface. Authentication and access control are implemented through a certificate-based system. The current status of the system is that hardware and software detail designs have been completed. An early version of the key management software has been completed and demonstrated. Hardware fabrication and systems integration are expected to take place over the next several months. Once completed the proof-of concept system will be used to explore issues of privacy, access control and authentication in relation to communications over emerging public networks.< > C2 - 2002/11/19/ C3 - Proceedings of the Symposium on Network and Distributed System Security DA - 2002/11/19/ DO - 10.1109/ndss.1995.390648 PB - IEEE Comput. Soc. Press SN - 0818670274 UR - http://dx.doi.org/10.1109/ndss.1995.390648 DB - Crossref ER - TY - CONF TI - Effectiveness of producer-initiated communication AU - Byrd, G.T. AU - Flynn, M.J. T2 - Thirty-First Hawaii International Conference on System Sciences AB - Producer-initiated communication mechanisms have been proposed to reduce communication latency in distributed shared memory systems. These mechanisms aim to move data close to its consumers, as soon as it is produced. The data is then available locally when needed by the consumer, avoiding the latency of retrieving it from global memory or from the producer's cache. Studies have shown that these sorts of mechanisms are effective, in that they reduce latency and improve execution time, compared to plain invalidate-based cache coherence. It is not clear, however, whether producer-initiated mechanisms provide a significant advantage over prefetch or other consumer-oriented mechanisms designed to hide or reduce latency. The authors look at the published evidence and draw some conclusions. C2 - 2002/11/27/ C3 - Proceedings of the Thirty-First Hawaii International Conference on System Sciences DA - 2002/11/27/ DO - 10.1109/hicss.1998.649281 PB - IEEE Comput. Soc SN - 0818682558 UR - http://dx.doi.org/10.1109/hicss.1998.649281 DB - Crossref ER - TY - CONF TI - On the exploitation of value prediction and producer identification to reduce barrier synchronization time AU - Ibrahim, K.Z. AU - Byrd, G.T. T2 - IEEE International Symposium on Parallel and Distributed Processing AB - Barrier synchronization is a source of inefficiency in many parallel programs, due to the association of many producer-consumer relations in with one synchronization variable. This inefficiency may consume a significant percentage of total execution time, especially as we increase the degree of parallelism while maintaining the problem size. Barrier synchronization wait time can be hidden by speculatively executing instructions after the barrier. The speculative execution must not violate the dependencies imposed by the program. Dependency violation causes rollback, incurring a penalty that may exceed the benefit of speculation. In this work, we investigate how to reduce the probability of rollback through the use of two different techniques: value prediction and producer identification. The first technique tries to break the dependency between the running processes. The second technique tries to respect only true dependencies by transforming the barrier synchronization into per-variable flags. Simulation results using scientific benchmarks mostly SPLASH-2, indicate that producer identification promises a greater potential reduction in synchronization time, close to actual dependency, and maintains rollback percentage below 10% for most benchmarks. C2 - 2002/11/13/ C3 - Proceedings 15th International Parallel and Distributed Processing Symposium. IPDPS 2001 DA - 2002/11/13/ DO - 10.1109/ipdps.2001.924981 PB - IEEE Comput. Soc SN - 0769509908 UR - http://dx.doi.org/10.1109/ipdps.2001.924981 DB - Crossref ER - TY - CONF TI - Design and implementation of acceptance monitor for building scalable intrusion tolerant system AU - Wang, Rong AU - Wang, Feiyi AU - Byrd, G.T. T2 - Tenth International Conference on Computer Communications and Networks AB - Intrusion detection research has so far mostly concentrated on techniques that effectively identify malicious behavior. No assurance can be assumed once the system is compromised. Intrusion tolerance, on the other hand, focuses on providing minimal level of services even when some components have been partially compromised. The challenges here are how to take advantage of fault tolerant techniques in the intrusion tolerant system context and how to deal with possible unknown attacks and compromised components so as to continue providing the service. This paper presents our work on applying one important fault tolerance technique, acceptance testing, for building scalable intrusion tolerant systems. First, we propose a general methodology for designing acceptance tests. An acceptance monitor architecture is proposed to apply various tests for detecting compromises based on the impact of the attacks. Second, we make a comprehensive vulnerability analysis on typical commercial-off-the-shelf (COTS) Web servers. Various acceptance testing modules are implemented to show the effectiveness of the proposed approach. By utilizing the fault tolerance techniques on intrusion tolerance system, we provide a mechanism for building reliable distributed services that are more resistant to both known and unknown attacks. C2 - 2002/11/13/ C3 - Proceedings Tenth International Conference on Computer Communications and Networks (Cat. No.01EX495) DA - 2002/11/13/ DO - 10.1109/icccn.2001.956241 PB - IEEE SN - 0780371283 UR - http://dx.doi.org/10.1109/icccn.2001.956241 DB - Crossref ER - TY - JOUR TI - Coding schemes for multislot messages in multichannel ALOHA with deadlines AU - Baron, D. AU - Birk, Y. T2 - IEEE Transactions on Wireless Communications AB - Slotted multichannel ALOHA is the access scheme of choice for short messages and for reserving channels for longer ones in many satellite-based networks. This paper proposes schemes for increasing the capacity (maximum attainable throughput) of multichannel slotted ALOHA subject to meeting a user-specified deadline with a (high) required probability, thereby jointly capturing the users' requirements and the system owner's desires. The focus is on short yet multislot messages. A key idea is to achieve a low probability of missing the deadline by permitting a large maximum resource expenditure per message, while holding the mean expenditure low in order to minimize "pollution." For a K-slot message, redundant single-slot fragments are constructed using block erasure-correcting codes, such that any K fragments suffice for message reception. With multiround coding, an optimized number of fragments are transmitted in each round until K are received or the deadline is reached. Even with very strict constraints, capacities that approach the 1/e limit are attained. The coding-reservation scheme raises capacity above 1/e by allowing the hub, upon receipt of any message fragment(s), to grant contention-free slots for the remaining required fragments. Both schemes are also adapted for use with single-transmitter stations at a small performance penalty in most cases. Finally, because capacity is maximized by minimizing the mean per-message transmission resources, the transmission scheme is also energy-efficient. DA - 2002/4// PY - 2002/4// DO - 10.1109/7693.994823 VL - 1 IS - 2 SP - 292-301 J2 - IEEE Trans. Wireless Commun. OP - SN - 1536-1276 UR - http://dx.doi.org/10.1109/7693.994823 DB - Crossref KW - coding KW - deadline KW - delay KW - energy-efficient design KW - multichannel ALOHA KW - reservation ALOHA KW - satellite ER - TY - CONF TI - Cerenkov generation of confined acoustic and optical phonons in quantum wells AU - Kim, Ki Wook AU - Komirenko, Sergiy M. AU - Kochelap, Viatcheslav A. AU - Stroscio, Michael A. T2 - Symposium on Integrated Optoelectronic Devices A2 - Tsen, Kong-Thon F. A2 - Song, Jin-Joo A2 - Jiang, Hongxing AB - It is well known for bulk semiconductors that amplification (generation) of a phonon mode can be achieved via the Cerenkov effect when the electron drift velocity exceeds the phonon phase velocity. The following three requirements are necessary for practical use of this effect: high electron mobilities, large electron densities, and strong coupling between electrons and phonons. In this report we show that in quantum well heterostructures these requirements can be met and both confined acoustic and confined optical phonon modes can be efficiently generated (amplified) by the drift of two-dimensional carriers. General formulae for the gain coefficient as a function of the acoustic phonon frequency and structure parameters as well as for the confined phonon increment are derived. Taking into account the electron-acoustic-phonon interaction through the deformation potential as well as the piezoelectric interaction, we found that amplification coefficient can reach hundreds of 1/cm for the AlGaAs-based heterostructures and thousands of 1/cm for the SiGe-based heterostructures in the terahertz phonon frequency range. Amplification takes place in a spectrally separated and relatively narrow amplification bands. We show that the optical phonon increment depends critically on the electron drift velocity. Detailed analysis of the optical phonon increment as a function of phonon wavevector, electron-phonon coupling strength, electron temperature and drift velocity indicates that the electron drift in selectively doped AlAs/GaAs/AlAs and GaSb/InSb/GaAs quantum wells can generate coherent confined optical modes. Finally, we discuss nonlinear mechanisms which stabilize the increase of phonon population and lead to the steady state phonon generation. C2 - 2002/6/13/ C3 - Ultrafast Phenomena in Semiconductors VI DA - 2002/6/13/ DO - 10.1117/12.470408 PB - SPIE UR - http://dx.doi.org/10.1117/12.470408 DB - Crossref KW - acoustic phonon KW - optical phonon KW - coherent phonon generation KW - high-frequency electric generation ER - TY - CONF TI - Optical phonons in wurtzite and cubic structures AU - Kim, K.W. AU - Komirenko, S.M. AU - Stroscio, M.A. AU - Kochelap, V.A. T2 - 2001 International Semiconductor Device Research Symposium. Symposium AB - Optical phonons play a crucial role in polar semiconductors due to their strong interaction with electrons. The phonons and electron-phonon interaction have been investigated primarily in cubic materials due to relative simplicity of the phonon spectra in these optically isotropic materials. Recent interest in group III-nitrides, which usually crystallize in a hexagonal wurtzite structure, as well as the needs of contemporary technologies in nanoscale sources of high-frequency oscillations have brought up a number of additional questions related to phonon physics in solid state devices. In this abstract, we summarize the main differences between the optical phonon spectra in wurtzite and cubic structures and point to the significance of the electron-phonon interaction strength for a number of phonon-related problems and applications. C2 - 2002/11/13/ C3 - 2001 International Semiconductor Device Research Symposium. Symposium Proceedings (Cat. No.01EX497) DA - 2002/11/13/ DO - 10.1109/ISDRS.2001.984578 PB - IEEE SN - 0780374320 UR - http://dx.doi.org/10.1109/ISDRS.2001.984578 DB - Crossref ER - TY - CONF TI - Channel engineering in n-MOSFETs: scaling trends for hot electron injection and device degradation AU - Williams, S.C. AU - Hulfachor, R.B. AU - Kim, K.W. AU - Littlejohn, M.A. T2 - 1996 54th Annual Device Research Conference Digest AB - Drain engineering has been the primary focus of efforts to overcome reliability trade-offs dictated by channel hot electron injection (CHEI) into the oxide in MOSFET devices. Comparatively few studies on channel, or vertical, engineering have been conducted, though recently there has been increased interest in its applications. In this study we employ a reliability simulation package to investigate the potential of channel engineering for future silicon technology by comparing scaling trends of CHEI and device sensitivity to the resulting distributions of induced interface damage for both Super-Steep-Retrograde (SSR) channel designs and more conventional (CONV) channel designs. C2 - 2002/12/24/ C3 - 1996 54th Annual Device Research Conference Digest DA - 2002/12/24/ DO - 10.1109/DRC.1996.546299 PB - IEEE SN - 0780333586 UR - http://dx.doi.org/10.1109/DRC.1996.546299 DB - Crossref ER - TY - JOUR TI - Intra-chip wireless interconnect for clock distribution implemented with integrated antennas, receivers, and transmitters AU - Floyd, B.A. AU - Hung, Chih-Ming AU - O, K.K. T2 - IEEE Journal of Solid-State Circuits AB - A wireless interconnect system which transmits and receives RF signals across a chip using integrated antennas, receivers, and transmitters is proposed and demonstrated. The transmitter consists of a voltage-controlled oscillator, an output amplifier, and an antenna, while the receiver consists of an antenna, a low-noise amplifier, a frequency divider, and buffers. Using a 0.18-/spl mu/m CMOS technology, each of these individual circuits is demonstrated at 15 GHz. Wireless interconnection for clock distribution is then demonstrated in two stages. First, a wireless transmitter with integrated antenna generates and broadcasts a 15-GHz global clock signal across a 5.6-mm test chip, and this signal is detected using receiving antennas. Second, a wireless clock receiver with an integrated antenna detects a 15-GHz global clock signal supplied to an on-chip transmitting antenna located 5.6 mm away from the receiver, and generates a 1.875-GHz local clock signal. This is the first known demonstration of an on-chip clock transmitter with an integrated antenna and the second demonstration of a clock receiver with an integrated antenna, where the receiver's frequency and interconnection distance have approximately been doubled over previous results. DA - 2002/5// PY - 2002/5// DO - 10.1109/4.997846 VL - 37 IS - 5 SP - 543-552 J2 - IEEE J. Solid-State Circuits OP - SN - 0018-9200 UR - http://dx.doi.org/10.1109/4.997846 DB - Crossref KW - 15 GHz KW - clock distribution KW - frequency divider KW - injection locking KW - integrated antenna KW - low noise amplifier (LNA) KW - on-chip antenna KW - RF CMOS KW - voltage-controlled oscillator (VCO) KW - wireless clock distribution KW - wireless interconnect KW - zigzag antenna ER - TY - JOUR TI - A 23.8-GHz SOI CMOS tuned amplifier AU - Floyd, B.A. AU - Shi, L. AU - Taur, Yuan AU - Lagnado, I. AU - O, K.K. T2 - IEEE Transactions on Microwave Theory and Techniques AB - A 23.8-GHz tuned amplifier is demonstrated in a partially scaled 0.1-/spl mu/m silicon-on-insulator CMOS technology. The fully integrated three-stage amplifier employs a common-gate, source-follower, and cascode with on-chip spiral inductors and MOS capacitors. The gain is 7.3 dB, while input and output reflection coefficients are -45 and -9.4 dB, respectively. Positive gain is exhibited beyond 26 GHz. The amplifier draws 53 mA from a 1.5-V supply. The measured on-wafer noise figure is 10 dB, while the input-referred third-order intercept point is -7.8 dBm. The results demonstrate that 0.1-/spl mu/m CMOS technology may be used for 20-GHz RF applications and suggest even higher operating frequencies and better performance for further scaled technologies. DA - 2002/9// PY - 2002/9// DO - 10.1109/tmtt.2002.802334 VL - 50 IS - 9 SP - 2193-2196 J2 - IEEE Trans. Microwave Theory Techn. LA - en OP - SN - 0018-9480 UR - http://dx.doi.org/10.1109/tmtt.2002.802334 DB - Crossref KW - CMOS KW - K-band KW - low-noise amplifier KW - negative resistance KW - silicon-on-insulator KW - SOI KW - spiral inductor KW - tuned amplifier ER - TY - JOUR TI - Medical imaging using capacitive micromachined ultrasonic transducer arrays AU - Johnson, Jeremy AU - Oralkan, Ömer AU - Demirci, Utkan AU - Ergun, Sanlı AU - Karaman, Mustafa AU - Khuri-Yakub, Pierre T2 - Ultrasonics AB - We are investigating the use of capacitive micromachined ultrasonic transducers (cMUT's) for use in medical imaging. We propose an ultrasound probe architecture designed to provide volumetric ultrasound imaging from within an endoscope channel. A complete automated experimental system has been implemented for testing the imaging performance of cMUT arrays. This PC-based system includes custom-designed circuit boards, a software interface, and resolution test phantoms. We have already fabricated 1D and 2D cMUT arrays, and tested the pulse-echo imaging characteristics of 1D arrays. Beamforming and image formation algorithms that aim to reduce the complexity of data acquisition hardware are tested via numerical simulations and using real data acquired from our system. DA - 2002/5// PY - 2002/5// DO - 10.1016/s0041-624x(02)00161-0 VL - 40 IS - 1-8 SP - 471-476 J2 - Ultrasonics LA - en OP - SN - 0041-624X UR - http://dx.doi.org/10.1016/s0041-624x(02)00161-0 DB - Crossref KW - capacitive micromachined ultrasonic transducer KW - medical imaging KW - three-dimensional ultrasound KW - two-dimensional ultrasound array ER - TY - JOUR TI - Capacitive micromachined ultrasonic transducers: next-generation arrays for acoustic imaging? AU - Oralkan, O. AU - Ergun, A.S. AU - Johnson, J.A. AU - Karaman, M. AU - Demirci, U. AU - Kaviani, K. AU - Lee, T.H. AU - Khuri-Yakub, B.T. T2 - IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control AB - Piezoelectric materials have dominated the ultrasonic transducer technology. Recently, capacitive micromachined ultrasonic transducers (CMUTs) have emerged as an alternative technology offering advantages such as wide bandwidth, ease of fabricating large arrays, and potential for integration with electronics. The aim of this paper is to demonstrate the viability of CMUTs for ultrasound imaging. We present the first pulse-echo phased array B-scan sector images using a 128-element, one-dimensional (1-D) linear CMUT array. We fabricated 64- and 128-element 1-D CMUT arrays with 100% yield and uniform element response across the arrays. These arrays have been operated in immersion with no failure or degradation in performance over the time. For imaging experiments, we built a resolution test phantom roughly mimicking the attenuation properties of soft tissue. We used a PC-based experimental system, including custom-designed electronic circuits to acquire the complete set of 128 x 128 RF A-scans from all transmit-receive element combinations. We obtained the pulse-echo frequency response by analyzing the echo signals from wire targets. These echo signals presented an 80% fractional bandwidth around 3 MHz, including the effect of attenuation in the propagating medium. We reconstructed the B-scan images with a sector angle of 90 degrees and an image depth of 210 mm through offline processing by using RF beamforming and synthetic phased array approaches. The measured 6-dB lateral and axial resolutions at 135 mm depth were 0.0144 radians and 0.3 mm, respectively. The electronic noise floor of the image was more than 50 dB below the maximum mainlobe magnitude. We also performed preliminary investigations on the effects of crosstalk among array elements on the image quality. In the near field, some artifacts were observable extending out from the array to a depth of 2 cm. A tail also was observed in the point spread function (PSF) in the axial direction, indicating the existence of crosstalk. The relative amplitude of this tail with respect to the mainlobe was less than -20 dB. DA - 2002/11// PY - 2002/11// DO - 10.1109/tuffc.2002.1049742 VL - 49 IS - 11 SP - 1596-1610 J2 - IEEE Trans. Ultrason., Ferroelect., Freq. Contr. OP - SN - 0885-3010 UR - http://dx.doi.org/10.1109/tuffc.2002.1049742 DB - Crossref ER - TY - JOUR TI - Novel hardware architecture for fast address lookups AU - Mehrotra, P. AU - Franzon, P.D. T2 - IEEE Communications Magazine AB - For every packet an IP router receives, it makes a routing decision based on the packet's destination address. The router's forwarding rate is usually limited by the rate at which it can make these decisions. We describe a new method for implementing route lookups in hardware. Our method can be implemented in the forwarding engine of a network processor or router using a small on-chip SRAM and an off-chip DRAM, and it achieves a rate of one lookup per DRAM random access time. We present our method and discuss an implementation that uses a DRAM with 64 ns random access time to give over 15 million lookups per second. Our tests show that the method performs well for realistic routing tables while using only modest amounts of memory. DA - 2002/11// PY - 2002/11// DO - 10.1109/mcom.2002.1046995 VL - 40 IS - 11 SP - 66-71 J2 - IEEE Commun. Mag. LA - en OP - SN - 0163-6804 UR - http://dx.doi.org/10.1109/mcom.2002.1046995 DB - Crossref ER - TY - JOUR TI - Foreword AU - Nagle, H.T. AU - Gardner, J.W. AU - Persaud, K. T2 - IEEE Sensors Journal DA - 2002/6// PY - 2002/6// DO - 10.1109/jsen.2002.801137 VL - 2 IS - 3 SP - 131-132 J2 - IEEE Sensors J. OP - SN - 1530-437X 1558-1748 UR - http://dx.doi.org/10.1109/jsen.2002.801137 DB - Crossref ER - TY - BOOK TI - Handbook of Machine Olfaction AU - Libraries, NC State University A3 - Pearce, Tim C. A3 - Schiffman, Susan S. A3 - Nagle, H. Troy A3 - Gardner, Julian W. DA - 2002/12/9/ PY - 2002/12/9/ DO - 10.1002/3527601597 OP - PB - Wiley-VCH Verlag GmbH & Co. KGaA SN - 3527303588 3527601597 UR - http://dx.doi.org/10.1002/3527601597 DB - Crossref ER - TY - CONF TI - Performance analysis of automotive power systems: effects of power electronic intensive loads and electrically-assisted propulsion systems AU - Lukic, SM AU - Emadi, A T2 - IEEE C2 - 2002/// C3 - Proceedings IEEE 56th Vehicular Technology Conference DA - 2002/// VL - 3 SP - 1835-1839 ER - TY - JOUR TI - Design and Simulation of Hybrid-Electric Vehicle (Spring 2002) IPRO 326 AU - Duo, Sijie AU - Koo, Gary AU - Shechtman, Sean AU - Kohanim, Sahar AU - Gangireddy, Sandeep AU - Rodriguez, Fernando AU - Lukic, Srdjan AU - Bodakh, Hani AU - Dubanski, Darius DA - 2002/// PY - 2002/// ER - TY - CONF TI - Advantages of hybrid electric vehicles with parallel drivetrain configurations AU - Lukic, SM AU - Emadi, A C2 - 2002/// C3 - Proc. 2002 Electrical Manufacturing and Coil Winding Expo. DA - 2002/// ER - TY - CONF TI - A PSIM-based modeling tool for conventional, electric, and hybrid electric vehicles studies AU - Onoda, S AU - Lukic, SM AU - Nasiri, A AU - Emadi, A T2 - IEEE C2 - 2002/// C3 - Proceedings IEEE 56th Vehicular Technology Conference DA - 2002/// VL - 3 SP - 1676-1680 ER - TY - CONF TI - Ultra-wideband high data rate short range wireless links AU - Van’t Hof, J.P. AU - Stancil, D.D. C2 - 2002/// C3 - IEEE Vehicular Technology Conference DA - 2002/// VL - 1 SP - 85-89 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036055918&partnerID=MN8TOARS ER - TY - JOUR TI - Theoretical estimates of HVAC duct channel capacity for high-speed internet access AU - Xhafa, A.E. AU - Tonguz, O.K. AU - Cepni, A.G. AU - Stancil, D.D. AU - Nikitin, P.V. AU - Brodtkorb, D. T2 - IEEE International Conference on Communications AB - We report theoretical channel capacity estimates of heating, ventilation, and air-conditioning (HVAC) ducts based on multi-carrier transmission that uses M-QAM modulation and measured channel responses at 2.4 GHz Industrial, Scientific, and Medical (ISM) band. It is shown that, data rates in excess of 1 Gbps are possible over distances up to 500 m in "matched" ducts (one can think of "matched" ducts as user-friendly ducts, since "matching" can, in principle, eliminate all the multipath reflections in HVAC ducts). Our work also shows that data rates in excess of 300 Mbps are possible over distances up to 500 m even in the presence of significant multipath reflections. DA - 2002/// PY - 2002/// DO - 10.1109/ICC.2002.996993 VL - 2 SP - 936-939 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036279625&partnerID=MN8TOARS ER - TY - CONF TI - Refraction analysis at a step discontinuity of a three-dimensional multimode slab waveguide for incident modes with arbitrary direction AU - Itagi, A. AU - Schlesinger, T.E. AU - Stancil, D.D. AB - In this paper we present an analysis for the refraction of modes at the step discontinuity of a multimode slab waveguide. This analysis can be used analogous to ray tracing in conventional optics to obtain focusing properties of waveguide lenses. Apart from application in optical heads, this analysis finds application in communication systems that make widespread use of integrated optics. C2 - 2002/// C3 - 2002 International Symposium on Optical Memory and Optical Data Storage Topical Meeting, ISOM/ODS 2002 - Joint International Symposium on Optical Memory and Optical Data Storage 2002, Technical Digest DA - 2002/// DO - 10.1109/OMODS.2002.1028650 SP - 308-310 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84962815566&partnerID=MN8TOARS ER - TY - CONF TI - RF propagation in an HVAC duct system: Impulse response characteristics of the channel AU - Nikitin, P.V. AU - Stancil, D.D. AU - Tonguz, O.K. AU - Xhafa, A.E. AU - Cepni, A.G. C2 - 2002/// C3 - IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) DA - 2002/// VL - 2 SP - 726-729 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036075825&partnerID=MN8TOARS ER - TY - CONF TI - Optical fields of a sub-wavelength metal aperture in a Very Small Aperture Laser (VSAL) AU - Itagi, A. AU - Chen, F. AU - Stancil, D.D. AU - Schlesinger, T.E. AB - The effect of metal thickness on the transmitted optical field of a sub-wavelength metal aperture on a Very Small Aperture Laser (VSAL) is modeled and studied experimentally. The experimental results were obtained in the far field, on a VSAL fabricated from a commercial semiconductor diode laser using Focused Ion Beam Etching (FIBE). The optical field in the near-field region of the VSAL was modeled by the Finite Difference Time Domain (FDTD) method. In this model, the laser was assumed to be decoupled from the aperture. C2 - 2002/// C3 - Proceedings of SPIE - The International Society for Optical Engineering DA - 2002/// DO - 10.1117/12.453436 VL - 4342 SP - 277-284 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036386243&partnerID=MN8TOARS ER - TY - CONF TI - Multi-carrier signal transmission through HVAC ducts: Experimental results for channel capacity AU - Cepni, A.G. AU - Xhafa, A.E. AU - Nikitin, P.V. AU - Stancil, D.D. AU - Tonguz, O.K. AU - Brodtkorb, D. C2 - 2002/// C3 - IEEE Vehicular Technology Conference DA - 2002/// VL - 56 SP - 331-335 M1 - 1 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036447404&partnerID=MN8TOARS ER - TY - JOUR TI - Mark shapes in hybrid recording AU - Herget, P. AU - Rausch, T. AU - Shiela, A.C. AU - Stancil, D.D. AU - Schlesinger, T.E. AU - Zhu, J.-G. AU - Bain, J.A. T2 - Applied Physics Letters AB - We describe the theoretical and experimental investigation of mark shapes in thermally assisted or hybrid recording. The effect of alignment was studied by recording marks on perpendicular TbFeCo media using a commercial recording head and 840 nm laser. We found that mark shapes are primarily controlled through laser/head alignment, and that maximally straight transitions are obtained by placing the laser spot on the leading pole tip near the gap. Simulations of the recording process confirm the experimental findings and are used in conjunction with static write contours to show how transitions form. DA - 2002/// PY - 2002/// DO - 10.1063/1.1454230 VL - 80 IS - 10 SP - 1835-1837 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-79956047799&partnerID=MN8TOARS ER - TY - CONF TI - High density substrate incident magneto-optic recording using a solid immersion lens AU - Karns, D. AU - Stancil, D.D. AU - Vijaya Kumar, B.V.K. AU - Schlesinger, T.E. AB - A system demonstrating ultra-high optical recording densities is presented. A substrate incident solid immersion lens was implemented and integrated into a blue wavelength optical spin stand. The spin stand was designed to work without a focus or tracking servo. The optical readout spot size was determined to be approximately 250 nm from the impulse response of the system and was also verified by swept sine wave methods. The system signal-to-noise characteristics were determined by integration of the Fourier decomposition of the readout signal and by autocorrelation techniques. The signal to noise ratio for low frequency data was 23 dB. Finally, domains as small as 80 nm were recorded and readout using this system and the associated signal to noise ratio was shown to be approximately 10 dB.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. C2 - 2002/// C3 - Proceedings of SPIE - The International Society for Optical Engineering DA - 2002/// DO - 10.1117/12.453384 VL - 4342 SP - 213-219 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036381204&partnerID=MN8TOARS ER - TY - CONF TI - Experimental test bed for hybrid recording AU - Rausch, T. AU - Herget, P. AU - Bain, J.A. AU - Zhu, J. AU - Stancil, D.D. AU - Schlesinger, T.E. AB - An experimental test bed for investigating the hybrid recording process and that allows for the precise visual alignment of the optical spot and magnetic head is described. Using this spin stand experiments have been performed on three types of hybrid recording where the critical bit dimensions are determined by using either, or both, the thermal and magnetic field profiles. By changing the relative alignment of the optical spot and magnetic head in the down track position four distinct types of marks unique to the hybrid recording process are observed. C2 - 2002/// C3 - Proceedings of SPIE - The International Society for Optical Engineering DA - 2002/// DO - 10.1117/12.453398 VL - 4342 SP - 502-510 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036379974&partnerID=MN8TOARS ER - TY - JOUR TI - Experimental investigation of domain expansion speeds in MAMMOS AU - Herget, P. AU - Van Kesteren, H.W. AU - Verschuren, C.A. AU - Stancil, D.D. AU - Schlesinger, T.E. T2 - IEEE Transactions on Magnetics AB - The speeds of the domain expansion and collapse processes in a magnetic amplifying magneto-optical system (MAMMOS) recording system were experimentally measured with a high-speed photodetector. Data was collected for a range of read powers and field values, the average rise and fall times were extracted, and the delay between the field switching and the domain collapse was examined. The minimum measured expansion and collapse times were 1.6 and 4.5 ns, respectively, and the field switching to collapse delay was found to be about 20 ns with a spread of 20 ns. Theories on the expansion and collapse processes and an explanation of the delay are presented. DA - 2002/// PY - 2002/// DO - 10.1109/TMAG.2002.801856 VL - 38 IS - 5 I SP - 2099-2101 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036762385&partnerID=MN8TOARS KW - magnetic domain expansion KW - magnetic amplifying magneto-optical system (MAMMOS) KW - super resolution ER - TY - CONF TI - Experimental effects of laser power on the writability and PW50 in a heat assisted longitudinal recording system AU - Rausch, T. AU - Bain, J.A. AU - Stancil, D.D. AU - Schlesinger, T.E. AU - Challener, W.A. AU - McDaniel, T. AU - Deeman, N. AU - Brucker, C. AB - In a heat assisted magnetic recording (HAMR) system, light from a laser diode is used to heat the medium which assists in the recording process by temporarily reducing the coercivity during writing. The recorded marks are read back using a magnetoresistive (MR) sensor that senses the stray flux from a magnetic transition. In this paper we examine the effects of the laser power on the writability and the pulse width at half maximum (PW/sub 50/) for granular longitudinal media. C2 - 2002/// C3 - 2002 International Symposium on Optical Memory and Optical Data Storage Topical Meeting, ISOM/ODS 2002 - Joint International Symposium on Optical Memory and Optical Data Storage 2002, Technical Digest DA - 2002/// DO - 10.1109/OMODS.2002.1028601 SP - 162-164 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84962878574&partnerID=MN8TOARS ER - TY - JOUR TI - Doubling wireless channel capacity using co-polarised, co-located electric and magnetic dipoles T2 - Electronics Letters AB - Experiments are described demonstrating the ability to realise independent information channels using co-located, co-polarised electric and magnetic dipoles in the presence of multipath propagation. The calculated information capacity is in good agreement with a random matrix channel model. DA - 2002/// PY - 2002/// DO - 10.1049/el:20020442 VL - 38 IS - 14 SP - 746-747 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0037019195&partnerID=MN8TOARS ER - TY - CONF TI - Domain position detection MAMMOS AU - Herget, P. AU - Schlesinger, T.E. AU - Stancil, D.D. AB - This paper introduces a new technique for reading and writing data in a MAMMOS system in which the position rather than the presence of domains is detected. We will refer to this new technique as domain position detection or DPD-MAMMOS. DPD-MAMMOS has several advantages over conventional MAMMOS and mitigates a number of common problems. Through computer simulation, it is shown how this technique can increase power margins and increase storage density. At the same time, DPD-MAMMOS eliminates the need for clock recovery, and relaxes the requirements on coil design. C2 - 2002/// C3 - 2002 International Symposium on Optical Memory and Optical Data Storage Topical Meeting, ISOM/ODS 2002 - Joint International Symposium on Optical Memory and Optical Data Storage 2002, Technical Digest DA - 2002/// DO - 10.1109/OMODS.2002.1028702 SP - 22-24 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84962910729&partnerID=MN8TOARS ER - TY - JOUR TI - An integrated read/write head for hybrid recording AU - Schlesinger, T.E. AU - Rausch, T. AU - Itagi, A. AU - Zhu, J. AU - Bain, J.A. AU - Stancil, D.D. T2 - Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers DA - 2002/// PY - 2002/// VL - 41 IS - 3 B SP - 1821-1824 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036509236&partnerID=MN8TOARS ER - TY - CONF TI - An empirical path loss model for HVAC duct systems AU - Tonguz, O.K. AU - Stancil, D.D. AU - Xhafa, A.E. AU - Cepni, A.G. AU - Nikitin, P.V. AU - Brodtkorb, D. C2 - 2002/// C3 - Conference Record / IEEE Global Telecommunications Conference DA - 2002/// VL - 2 SP - 1850-1854 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0036967476&partnerID=MN8TOARS ER - TY - PAT TI - Synchronous memory sharing based on cycle stealing AU - Fadavi-Ardekani, J. AU - Kermani, B. AU - Soto, W. G. AU - Niescier, R. J. AU - You, F. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - PAT TI - Programmable priority encoder AU - Kermani, B. G. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - PAT TI - Method and apparatus for providing noise immunity for a binary signal path on a chip AU - Kermani, B. G. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - PAT TI - Thin film transistors and method of forming thin film transistors AU - Batra, S. AU - Manning, M. AU - Banerjee, S. AU - Damiano, D. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - PAT TI - Semiconductor structures with trench contacts AU - Huang, Q. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - CONF TI - Outcomes assessment: developing an electronic assessment database as a model for collection and analysis of data AU - Spurlin, J. E. AU - Rajala, S. A. AU - Lavelle, J. P. AU - Hoskins, O. J. C2 - 2002/// C3 - American Society for Engineering Education DA - 2002/// ER - TY - PAT TI - Nanowire arrays AU - Ying, J. Y. AU - Zhang, Z. AU - Zhang, L. AU - Dresselhaus, M. S. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - PAT TI - Diode-assisted gate turn-off thyristor AU - Li, Y. Huang AU - A. Q., AU - Motto, K. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - CONF TI - A large, fast instruction window for tolerating cache misses AU - Lebeck, A. R. AU - Koppanalil, J. J. AU - Li, T. AU - Patwardhan, J. AU - Rotenberg, E. AB - Instruction window size is an important design parameter for many modern processors. This paper presents a new instruction window design targeted at achieving the latency tolerance of large windows with the clock cycle time of small windows. The key observation is that instructions dependent on a long latency operation (e.g., cache miss) cannot execute until that source operation completes. These instructions are moved out of the conventional, small, issue queue to a much larger waiting instruction buffer (WIB). When the long latency operation completes, the instructions are reinserted into the issue queue. In this paper, we focus specifically on load cache misses and their dependent instructions. Simulations reveal that, for an 8-way processor, a 2K-entry WIB with a 32-entry issue queue can achieve speedups of 20%, 84%, and 50% over a conventional 32-entry issue queue for a subset of the SPEC CINT2000, SPEC CFP2000, and Olden benchmarks, respectively. C2 - 2002/// C3 - 29th Annual International Symposium on Computer Architecture: Proceedings : 25-29 May, 2002, Anchorage, Alaska DA - 2002/// DO - 10.1109/isca.2002.1003562 SP - 59-70 PB - Los Alamitos, CA: IEEE Computer Society SN - 076951605X ER - TY - CONF TI - A case for dynamic pipeline scaling AU - Koppanalil, J. AU - Ramrakhyani, P. AU - Desai, S. AU - Vaidyanathan, A. AU - Rotenberg, E. AB - Energy consumption can be reduced by scaling down frequency when peak performance is not needed. A lower frequency permits slower circuits, and hence a lower supply voltage. Energy reduction comes from voltage reduction, a technique called Dynamic Voltage Scaling (DVS).This paper makes the case that the useful frequency range of DVS is limited because there is a lower bound on voltage. Lowering frequency permits voltage reduction until the lowest voltage is reached. Beyond that point, lowering frequency further does not save energy because voltage is constant.However, there is still opportunity for energy reduction outside the influence of DVS. If frequency is lowered enough, pairs of pipeline stages can be merged to form a shallower pipeline. The shallow pipeline has better instructions-per-cycle (IPC) than the deep pipeline. Since energy also depends on IPC, energy is reduced for a given frequency. Accordingly, we propose Dynamic Pipeline Scaling (DPS). A DPS-enabled deep pipeline can merge adjacent pairs of stages by making the intermediate latches transparent and disabling corresponding feedback paths. Thus, a DPS-enabled pipeline has a deep mode for higher frequencies within the influence of DVS, and a shallow mode for lower frequencies. Shallow mode extends the frequency range for which energy reduction is possible. For frequencies outside the influence of DVS, a DPS-enabled deep pipeline consumes from 23% to 40% less energy than a rigid deep pipeline. C2 - 2002/// C3 - Proceedings of the International Conference on Compilers, Architecture, and Synthesis for Embedded Systems|h: 2002, Greenoble, France, October 08-11, 2002 DA - 2002/// DO - 10.1145/581630.581632 SP - 1-8 PB - New York: ACM Press SN - 1581137265 ER - TY - JOUR TI - Untitled AU - Al-Dhahir, N AU - Giannakis, GB AU - Hochwald, B AU - Hughes, BL AU - Marzetta, TL T2 - IEEE TRANSACTIONS ON SIGNAL PROCESSING DA - 2002/10// PY - 2002/10// DO - 10.1109/tsp.2002.804127 VL - 50 IS - 10 SP - 2381-2384 SN - 1053-587X ER - TY - JOUR TI - Raised cosine approximation signalling technique for reduced simultaneous switching noise AU - Bashirullah, R AU - Liu, W T2 - ELECTRONICS LETTERS AB - A new technique for reducing noise crosstalk due to inductive effects in high-speed switching environments is presented. A signalling scheme based on raised cosine approximation (RCA) pulses is used to achieve gradual buffer turn on without any speed penalties. A new current-mode RCA line driver is proposed and incorporated in a 16 bit 1 Gbit/s off-chip transmitter. Simulation results based on TSMC 0.25 µm show ground bounce noise reduction greater than 40%. DA - 2002/10/10/ PY - 2002/10/10/ DO - 10.1049/el:20020852 VL - 38 IS - 21 SP - 1256-1258 SN - 1350-911X ER - TY - PAT TI - Modular observation crawler and sensing instrument and method for operating same AU - Grant, E. AU - Muth, J. F. AU - Cottle, J. S. AU - Dessent, B. E. AU - Cox, J. A. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - CHAP TI - Analyzing intensive intrusion alerts via correlation AU - Ning, P. AU - Cui, Y. AU - Reeves, D. S. T2 - Recent advances in intrusion detection, 5th international symposium, RAID 2002, Zurich, Switzerland, October 16-18, 2002: Proceedings A2 - A. Wespi, G. Vigna A2 - Deri, L. AB - Traditional intrusion detection systems (IDSs) focus on low-level attacks or anomalies, and raise alerts independently, though there may be logical connections between them. In situations where there are intensive intrusions, not only will actual alerts be mixed with false alerts, but the amount of alerts will also become unmanageable. As a result, it is difficult for human users or intrusion response systems to understand the alerts and take appropriate actions. Several complementary alert correlation methods have been proposed to address this problem. As one of these methods, we have developed a framework to correlate intrusion alerts using prerequisites of intrusions. In this paper, we continue this work to study the feasibility of this method in analyzing real-world, intensive intrusions. In particular, we develop three utilities (called adjustable graph reduction, focused analysis, and graph decomposition) to facilitate the analysis of large sets of correlated alerts. We study the effectiveness of the alert correlation method and these utilities through a case study with the network traffic captured at the DEF CON 8 Capture the Flag (CTF) event. Our results show that these utilities can simplify the analysis of large amounts of alerts, and also reveals several attack strategies that were repeatedly used in the DEF CON 8 CTF event. CN - QA76.9 .A25 R34 2002 PY - 2002/// DO - 10.1007/3-540-36084-0_5 VL - 2516 SP - 74-94 PB - Berlin; New York: Springer SN - 3540000208 ER - TY - JOUR TI - The jakes fading model for antenna arrays incorporating azimuth spread AU - Fulghum, TL AU - Molnar, KJ AU - Duel-Hallen, A T2 - IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY AB - A new method for simulating the multiplicative fading of the narrow-band, flat wireless channel for antenna array receivers is presented. The new approach produces a set of fading waveforms, one waveform associated with each receiver element, in which the waveforms are appropriately correlated to take into account the spread, or dispersion, in the azimuth (arrival angle) of the received signal. The new method is an extension of the Jakes (1974) method of simulating fading in which the appropriate correlation of the set of waveforms is accomplished by directly considering the azimuth of scatterers in a particular distribution about the mobile transmitter. The models used for this cluster of scatterers are a ring and a disk of scatterers. Further modifications of the disk model permit the generation of fading waveforms which are correlated in a manner which reflect actual field measurements of azimuth dispersion. Analytical correlation of these models is reviewed for purposes of verification with the waveforms generated by the method. DA - 2002/9// PY - 2002/9// DO - 10.1109/TVT.2002.801742 VL - 51 IS - 5 SP - 968-977 SN - 1939-9359 UR - http://dx.doi.org/10.1109/TVT.2002.801742 KW - antenna arrays KW - azimuth dispersion KW - channel modeling KW - Jakes fading model ER - TY - JOUR TI - Laterally doped heterostructures for III–N lasing devices AU - Komirenko, S. M. AU - Kim, K. W. AU - Kochelap, V. A. AU - Zavada, J. M. T2 - Applied Physics Letters AB - To achieve a high-density electron-hole plasma in group-III nitrides for efficient light emission, we propose a planar two-dimensional (2D) p-i-n structure that can be formed in the quantum well layers due to efficient activation of donors and acceptors in the laterally, selectively doped barriers. We show that strongly nonequilibrium 2D electron-hole plasma with density above 1012 cm−2 can be realized in the i region of the laterally biased p-i-n structure, enabling the formation of interband population inversion and stimulated emission from such a lateral current pumped emitter (LACE). We suggest that implementation of the lateral p-i-n structures provides an efficient way of utilizing potential-profile-enhanced doping of superlattices and quantum wells for electric pumping of nitride-based lasers. DA - 2002/12/9/ PY - 2002/12/9/ DO - 10.1063/1.1527985 VL - 81 IS - 24 SP - 4616-4618 J2 - Appl. Phys. Lett. LA - en OP - SN - 0003-6951 1077-3118 UR - http://dx.doi.org/10.1063/1.1527985 DB - Crossref ER - TY - JOUR TI - Global coupled EM-electrical-thermal simulation and experimental validation for a spatial power combining MMIC array AU - Batty, W AU - Christoffersen, CE AU - Yakovlev, AB AU - Whitaker, JF AU - Mortazawi, A AU - Al-Zayed, A AU - Ozkar, M AU - Ortiz, SC AU - Reano, RM AU - Yang, K AU - Katehi, LPB AU - Snowden, CM AU - Steer, MB T2 - IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES AB - A unique electromagnetic (EM)-electrothermal global simulation tool based on a universal error concept is presented. The advantages of this electrothermal model are illustrated by comparison with a commercial electrothermal circuit simulator. The first description of a fully physical, electrothermal, microwave circuit simulation, based on coupling of the Leeds Physical Model of MESFETs and high electron-mobility transistors, to a microwave circuit simulator, fREEDA (NCSU), is presented. The modeling effort is supported by parallel developments in electrooptic and thermal measurement. The first fully coupled EM-electrothermal global simulation of a large microwave subsystem, here a whole spatial power combining monolithic-microwave integrated-circuit (MMIC) array, is described. The simulation is partially validated by measurements of MMIC array temperature rise and temperature dependent S-parameters. Electrothermal issues for spatial power combiner operation and modeling are discussed. The computer-aided-design tools and experimental characterization described, provide a unique capability for the design of quasi-optical systems and for the exploration of the fundamental physics of spatial power combining devices. DA - 2002/12// PY - 2002/12// DO - 10.1109/TMTT.2002.805142 VL - 50 IS - 12 SP - 2820-2833 SN - 1557-9670 KW - electromagnetic (EM) measurements KW - electromagnetic (EM) modeling KW - electrothermal effects KW - global modeling and simulation KW - microwave circuits KW - power devices KW - quasi-optical power combining KW - spatial power combiners KW - thermal measurements KW - thermal modeling ER - TY - JOUR TI - Characterization of coil faults in an axial flux variable reluctance PM motor AU - Nelson, AL AU - Chow, MY T2 - IEEE TRANSACTIONS ON ENERGY CONVERSION AB - Variable-reluctance (VR) and switch-reluctance (SR) motors have been proposed for use in applications requiring a degree of fault tolerance. A range of topologies, of brushless SR and VR permanent-magnet (PM) motors are not susceptible to some types of faults, such as phase-to-phase shorts, and can often continue to function in the presence of other faults. In particular, coil-winding faults in a single stator coil may have relatively little effect on motor performance but may affect overall motor reliability, availability, and longevity. It is important to distinguish between and characterize various winding faults for maintenance and diagnostic purposes. These fault characterization and analysis results are a necessary first step in the process of motor fault detection and diagnosis for this motor topology. This paper examines rotor velocity damping due to stator winding turn-to-turn short faults in a fault-tolerant axial flux VR PM motor. In this type of motor, turn-to-turn shorts, due to insulation failures, have similar I-V characteristics as coil faults resulting from other problems, such as faulty maintenance or damage due to impact. In order to investigate the effects of these coil faults, a prototype axial flux VR PM motor was constructed. The motor was equipped with experimental fault simulation stator windings capable of simulating these and other types of stator winding faults. This paper focuses on two common types of winding faults and their effects on rotor velocity in this type of motor. DA - 2002/9// PY - 2002/9// DO - 10.1109/TEC.2002.801730 VL - 17 IS - 3 SP - 340-348 SN - 1558-0059 KW - axial flux motor KW - brushless dc motor KW - electric vehicle propulsion KW - failure analysis KW - fault tolerance KW - insulation failure KW - turn-to-turn fault KW - variable reluctance motor KW - winding fault ER - TY - JOUR TI - Spin-phase relaxation of two-dimensional holes localized in a fluctuating potential AU - Semenov, Y. G. AU - Borysenko, K. N. AU - Kim, K. W. T2 - Physical Review B AB - We investigate a mechanism of spin phase relaxation for holes localized by an in-plane potential fluctuation in a quantum well. Dephasing is caused by the hole spin precession in a magnetic field with a fluctuation in the transverse g factor linked to the depth and the shape of localizing potential. The mechanism can be recognized by the linear dependences on magnetic field and the quadratic dependence on quantum well width. Quantitative analyses show the importance of this relaxation mechanism for deep fluctuative states of holes. DA - 2002/9/3/ PY - 2002/9/3/ DO - 10.1103/physrevb.66.113302 VL - 66 IS - 11 SP - J2 - Phys. Rev. B LA - en OP - SN - 0163-1829 1095-3795 UR - http://dx.doi.org/10.1103/PhysRevB.66.113302 DB - Crossref ER - TY - JOUR TI - Designing heterostructures with predefined value of light-hole g factor for coherent solid-state quantum receiver AU - Kiselev, A.A AU - Kim, K.W AU - Yablonovitch, E T2 - Physica E: Low-dimensional Systems and Nanostructures AB - In this paper, we give a consistent theoretical analysis of the in-plane Zeeman effect for quantum-confined light holes and evaluate possibilities to design structures with desired property of large g factor for these valence states. Numerical example is given for the technologically important InGaAs/InP both lattice-matched and strained heterosystems suitable for 1.3 and 1.55μm optoelectronic applications. DA - 2002/3// PY - 2002/3// DO - 10.1016/S1386-9477(02)00204-7 VL - 13 IS - 2-4 SP - 630-633 J2 - Physica E: Low-dimensional Systems and Nanostructures LA - en OP - SN - 1386-9477 UR - http://dx.doi.org/10.1016/S1386-9477(02)00204-7 DB - Crossref KW - semiconductor heterostructures KW - Zeeman effect KW - spin coherence KW - quantum communications ER - TY - JOUR TI - UV detectors and focal plane array imagers based on AlGaN p-i-n photodiodes AU - Long, J. P. AU - Varadaraajan, S. AU - Matthews, J. AU - Schetzina, J. F. T2 - Opto-electronics Review DA - 2002/// PY - 2002/// VL - 10 IS - 4 SP - 251-260 ER - TY - JOUR TI - Theory of electrodeposition of diamond nanoparticles AU - Bilbro, GL T2 - DIAMOND AND RELATED MATERIALS AB - We theoretically investigate the electrophoretic agglomeration of uncharged, possibly aggregated, nanodiamond (ND) particles, from liquid suspension onto a sharpened anode. We propose that the shape of such a ND agglomeration can be understood in terms of surface tension and Maxwell stress. DA - 2002/8// PY - 2002/8// DO - 10.1016/S0925-9635(02)00104-8 VL - 11 IS - 8 SP - 1572-1577 SN - 0925-9635 KW - nanodiamond KW - nanoparticle KW - electrophoresis KW - equilibrium ER - TY - CHAP TI - The economic impact of network pricing intervals AU - Fulp, E. W. AU - Reeves, D. S. T2 - Burkhard Stiller ...[et al.] (Eds.), From QoS provisioning to QoS charging: Third COST 263 International Workshop on Quality of Future Internet Services, QofIS 2002 and second International Workshop on Internet Charging and QoS Technologies, ICQT 2002, Zurich, Switzerland, October 16-18, 2002 AB - Interval pricing can provide an effective means of congestion control as well as revenue generation. Using this method, prices are fixed over intervals of time, providing adaptability and predictability. An important issue is the interval duration associated with price updates. While previous research has discussed the effect of interval lengths on congestion control, this paper investigates the economic impact of price interval duration. Smaller intervals yield higher profits since prices are more responsive to changing demands. However, experimental results indicate only a modest profit gain (no more than 5%) is achieved when smaller intervals are used as opposed to larger intervals (for example 100 times longer). Given users preferences toward fewer price changes, smaller price intervals may hold few economic benefits. CN - TK5105.875. I57 C67 2002 PY - 2002/// DO - 10.1007/3-540-45859-x_30 VL - 2511 SP - 315-324 PB - Berlin; New York: Springer SN - 3540443568 ER - TY - JOUR TI - Tunable barium strontium titanate thin film capacitors for RF and microwave applications AU - Tombak, A AU - Maria, JP AU - Ayguavives, F AU - Jin, Z AU - Stauf, GT AU - Kingon, AI AU - Mortazawi, A T2 - IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS AB - The measurement results for thin film barium strontium titanate (BST) based voltage tunable capacitors intended for RF applications are reported. At 9 V DC, BST capacitors fabricated using MOCVD (metalorganic chemical vapor deposition) method achieved 71% (3.4:1) tunability. The measured device quality factor (Q) for BST varactors is comparable with the device Q for commercially available varactor diodes of similar capacitance. The typical dielectric loss tangent was in the range 0.003-0.009 at VHF. Large signal measurement and modeling results for BST thin film capacitors are also presented. DA - 2002/1// PY - 2002/1// DO - 10.1109/7260.975716 VL - 12 IS - 1 SP - 3-5 SN - 1558-1764 KW - barium strontium titanate KW - (Ba,Sr)TiO3 KW - BST KW - ferroelectric KW - MOCVD KW - thin film KW - tunable capacitor KW - varactor ER - TY - JOUR TI - Spatial power splitting and combining based on the Talbot effect AU - Tayag, TJ AU - Steer, MB AU - Harvey, JF AU - Yakovlev, AB AU - Davis, J T2 - IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS AB - The Talbot effect, a multimode interference phenomenon, is investigated as a technique for combining power from solid-state devices in order to generate higher levels of microwave and millimeter-wave power in a process referred to as quasioptical or spatial power combining. We explore the feasibility of using the Talbot effect to implement a 1 /spl times/ 8 power splitter and an 8 /spl times/ 1 power combiner at 94 GHz. We report the first demonstration of the multimode interface phenomenon in a planar waveguide at 8 GHz. DA - 2002/1// PY - 2002/1// DO - 10.1109/7260.975718 VL - 12 IS - 1 SP - 9-11 SN - 1531-1309 KW - coupled mode analysis KW - interference KW - MMIC power amplifiers KW - multimode waveguides KW - power combiners KW - power dividers ER - TY - JOUR TI - Long-term reliability degradation of ultrathin dielectric films due to heavy-ion irradiation AU - Choi, BK AU - Fleetwood, DM AU - Schrimpf, RD AU - Massengill, LW AU - Galloway, KF AU - Shaneyfelt, MR AU - Meisenheimer, TL AU - Dodd, PE AU - Schwank, , JR AU - Lee, YM AU - John, RS AU - Lucovsky, G T2 - IEEE TRANSACTIONS ON NUCLEAR SCIENCE AB - High-energy ion-irradiated 3.3-nm oxynitride film and 2.2-nm SiO/sub 2/-film MOS capacitors show premature breakdown during subsequent electrical stress. This degradation in breakdown increases with increasing ion linear energy transfer (LET), increasing ion fluence, and decreasing oxide thickness. The reliability degradation due to high-energy ion-induced latent defects is explained by a simple percolation model of conduction through SiO/sub 2/ layers with irradiation and/or electrical stress-induced defects. Monitoring the gate-leakage current reveals the presence of latent defects in the dielectric films. These results may be significant to future single-event effects and single-event gate rupture tests for MOS devices and ICs with ultrathin gate oxides. DA - 2002/12// PY - 2002/12// DO - 10.1109/TNS.2002.805389 VL - 49 IS - 6 SP - 3045-3050 SN - 1558-1578 KW - heavy-ion irradiation KW - radiation effect KW - single-event effect KW - ultra-thin gate dielectric films ER - TY - CONF TI - Inter-packet delay based correlation for tracing encrypted connections through stepping stones AU - Wang, X. Y. AU - Reeves, D. S. AU - Wu, S. F. A2 - D. Gollmann, G. Karjoth A2 - Waidner, M. C2 - 2002/// C3 - Computer security--ESORICS 2002: 7th European Symposium on Research in Computer Security, Zurich, Switzerland, October 14-16, 2002: proceedings (Lecture notes in computer science ; 2502) DA - 2002/// VL - 2502 SP - 244-263 PB - New York: Springer SN - 0750306114 ER - TY - JOUR TI - Generation of high-frequency coherent acoustic phonons in superlattices under hopping transport. I. Linear theory of phonon instability AU - Glavin, B. A. AU - Kochelap, V. A. AU - Linnik, T. L. AU - Kim, K. W. AU - Stroscio, M. A. T2 - Physical Review B AB - In this work we consider the theory of high-frequency phonon generation in a weakly coupled doped semiconductor superlattice. Electric bias, applied to such a superlattice, destroys the electron minibands, creates electron states localized in the individual quantum wells, and forms population inversion between these states. An electric current occurs due to the phonon-induced interwell hops. We show that under such conditions the electric current produces a phonon instability: populations of phonon modes propagating almost collinearly with the superlattice axis increase exponentially in time. It is demonstrated that the population growth increment can be as high as several times ${10}^{8} {\mathrm{s}}^{\ensuremath{-}1},$ and considerably exceeds the internal phonon scattering rates. Also discussed are effects influencing the increment, such as a screening of the electron-phonon interaction and a modification of the phonon spectrum in superlattices. DA - 2002/1/30/ PY - 2002/1/30/ DO - 10.1103/physrevb.65.085303 VL - 65 IS - 8 SP - J2 - Phys. Rev. B LA - en OP - SN - 0163-1829 1095-3795 UR - http://dx.doi.org/10.1103/PhysRevB.65.085303 DB - Crossref ER - TY - JOUR TI - Electrical properties of Ru-based alloy gate electrodes for dual metal gate Si-CMOS AU - Misra, V AU - Zhong, HC AU - Lazar, H T2 - IEEE ELECTRON DEVICE LETTERS AB - In this letter, low resistivity Ru and Ru-Ta alloy films, deposited via reactive sputtering, were evaluated as gate electrodes for p- and n-MOSFET devices, respectively. MOSFETs fabricated via a conventional process flow indicated that the work functions of Ru and Ru-Ta alloys were compatible with p- and n-MOSFET devices, respectively. Both of the metal gated devices eliminated gate depletion effects. Good MOSFET characteristics, such as I/sub DS/-V/sub GS/ and mobility, were obtained for both Ru-gated PMOSFETs and Ru-Ta gated NMOSFETs. DA - 2002/6// PY - 2002/6// DO - 10.1109/LED.2002.1004233 VL - 23 IS - 6 SP - 354-356 SN - 0741-3106 KW - advanced gatestacks KW - CMOS KW - gate electrodes KW - metal alloy KW - metal gates KW - MOS transistors KW - Ru, Ru-Ta, Ta ER - TY - JOUR TI - Effect of riparian buffer width and vegetation type on shallow groundwater quality in the Middle Coastal Plain of North Carolina AU - Dukes, M. D. AU - Evans, R. O. AU - Gilliam, J. W. AU - Kunickis, S. H. T2 - Transactions of the ASAE AB - The effect of riparian buffer width and vegetation type on shallow groundwater quality has not been evaluatedin the Middle Coastal Plain of North Carolina. Four riparian buffer vegetation types and nobuffer (notill corn and ryerotation or pasture) were established at 8 and 15 m widths as follows: cool season grass (fescue), deeprooted grass (switchgrass), forest (pine and mixed hardwood), and native vegetation. Nested groundwater monitoring wells were installed at thefield/buffer edge and the stream edge in the middle of each riparian buffer plot at three depths. Most deep, middepth, andshallow wells were 3.0 m, 1.8 m, and 0.6 m deep from the ground surface to the top of the 0.6 m perforated section, respectively.Wells were sampled for 23 months beginning July 1998. Although the ditch well nitratenitrogen concentrations at the middlewell depth were significantly lower in the 15 m wide plots compared to the 8 m plots over half the monitoring period, extremeflooding as a result of a hurricane in the middle of the study confounded the results. The effect of vegetation was not significantat any time, including the nobuffer cropped and fertilized plots. The effect of vegetation was minimized because at the earlystage in the buffer vegetation establishment, vegetative cover and root mass were not fully developed, the hurricaneinducedflooding forced the reestablishment of several vegetation types (forest and fescue), and there was likely some mixing ofgroundwater flowing toward the vegetation plots. Establishment of buffers along streams where groundwater flowed awayfrom the stream did not result in lower groundwater nitrate levels. DA - 2002/// PY - 2002/// DO - 10.13031/2013.8528 VL - 45 IS - 2 SP - 327-336 ER - TY - JOUR TI - Demosaicking as a bilateral filtering process AU - Ramanath, R AU - Snyder, WE T2 - IMAGE PROCESSING: ALGORITHMS AND SYSTEMS AB - Digital Still Color Cameras sample the visible spectrum using an array of color filters overlaid on a CCD such that each pixel samples only one color band. The resulting mosaic of color samples is processed to produce a high resolution color image such that a value of a color band not sampled at a certain location is estimated from its neighbors. This is often referred to as 'demosaicking.' In this paper, we approach the process of demosaicking as a bilateral filtering process which is a combination of spatial domain filtering and filtering based on similarity measures. Bilateral filtering smooths images while preserving edges by means of nonlinear combinations of neighboring image pixel values. A bilateral filter can enforce similarity metrics (such as squared error or error in the CIELAB space) between neighbors while performing the typical filtering operations. We have implemented a variety of kernel combinations while performing demosaicking. This approach provides us with a means to denoise, sharpen and demosaic the image simultaneously. We thus have the ability to represent demosaicking algorithms as spatial convolutions. The proposed method along with a variety of existing demosaicking strategies are run on synthetic images and real-world images for comparative purposes. DA - 2002/// PY - 2002/// DO - 10.1117/12.467984 VL - 4667 SP - 236-244 SN - 0277-786X KW - bilateral filtering KW - color filter array KW - demosaicing KW - demosaicking KW - digital still camera KW - interpolation ER - TY - JOUR TI - Vertically scaled MOSFET gate stacks and junctions: How far are we likely to go? AU - Osburn, CM AU - Kim, I AU - Han, SK AU - De, I AU - Yee, KF AU - Gannavaram, S AU - Lee, SJ AU - Lee, CH AU - Luo, ZJ AU - Zhu, W AU - Hauser, , JR AU - Kwong, DL AU - Lucovsky, G AU - Ma, TP AU - Ozturk, MC T2 - IBM JOURNAL OF RESEARCH AND DEVELOPMENT AB - The vertical scaling requirements for gate stacks and for shallow extension junctions are reviewed. For gate stacks, considerable progress has been made in optimizing oxide/nitride and oxynitride dielectrics to reduce boron penetration and dielectric leakage compared to pure SiO 2 in order to allow sub-2-nm dielectrics. Several promising alternative material candidates exist for 1-nm equivalent oxide thickness (EOT)—for example, HfO 2 , ZrO 2 , and their silicates. Nevertheless, considerable challenges lie ahead if we are to achieve an EOT of less than 0.5 nm. If only a single molecular interface layer of oxide is needed to preserve high channel mobility, it seems likely that an EOT of 0.4–0.5 nm would represent the physical limit of dielectric scaling, but even then with a very high leakage (∼10 5 A/cm 2 ). For junctions, the main challenge lies in providing low parasitic series resistance as depths are scaled in order to reduce short-channel effects. Because contacts are ultimately expected to dominate the parasitic resistance, low-barrier-height contacts and/or very heavily doped junctions will be required. While ion implantation and annealing processes can certainly be extended to meet the junction-depth and series-resistance requirements for additional generations, alternative low-temperature deposition processes that produce either metastably or extraordinarily activated, abruptly doped regions seem better suited to solve the contact resistance problem. DA - 2002/// PY - 2002/// DO - 10.1147/rd.462.0299 VL - 46 IS - 2-3 SP - 299-315 SN - 2151-8556 ER - TY - JOUR TI - Structural, optical and magnetic properties of diluted magnetic semiconducting Zn1-xMnxO films AU - Tiwari, A AU - Jin, C AU - Kvit, A AU - Kumar, D AU - Muth, JF AU - Narayan, J T2 - SOLID STATE COMMUNICATIONS AB - We have investigated the structural, optical and magnetic properties of high quality epitaxial Zn1−xMnxO (diluted magnetic semiconductor) films. These films were deposited on (0001) sapphire substrate by a pulsed laser deposition technique. The nonequilibrium nature of the laser–material interaction allowed us to dope higher Mn contents (x=0.36) than allowed by thermal equilibrium limit (x∼0.13). All the films investigated here were found to be single phased and epitaxial with (0001) orientation. As the Mn concentration increases in the system, the c-axis lattice constant was found to increase linearly. Optical transmittance study showed an increase in the insulating band-gap (Eg) with increase in Mn atomic fraction x following Eg=3.270+2.760x−4.988x2eV. DC magnetization measurements showed the paramagnetic nature of the system. DA - 2002/// PY - 2002/// DO - 10.1016/S0038-1098(01)00464-1 VL - 121 IS - 6-7 SP - 371-374 SN - 0038-1098 KW - thin films KW - laser processing KW - epitaxy KW - X-ray scattering KW - optical properties ER - TY - JOUR TI - Novel cubic ZnxMg1-xO epitaxial hetero structures on Si (100) substrates AU - Narayan, J. AU - Sharma, A. K. AU - Kvit, A. AU - Jin, C. AU - Muth, J. F. AU - Holland, O. W. T2 - Solid State Communications DA - 2002/// PY - 2002/// VL - 121 IS - 1 SP - 9-13 ER - TY - JOUR TI - Meltblown structures formed by a robotic and meltblowing integrated system: Impact of process parameters on fiber orientation and diameter distribution AU - Farer, R AU - Seyam, AM AU - Ghosh, TK AU - Grant, E AU - Batra, SK T2 - TEXTILE RESEARCH JOURNAL AB - In a previous publication, we described a novel system that forms three-dimensional (3D) structures on 3D molds and two-dimensional (2D) structures on a rotating drum through proper integration of a laboratory scale meltblown unit with a small die and a six-axis robot. In this paper, we investigate the impact of take-up speed. die-to-collector distance (DCD). polymer throughput rate. and attenuating air pressure on the fiber orien tation and diameter distribution of 2D structures formed by the system. We introduce a new parameter, the fiber stream approach angle, which can be precisely controlled by the robot, and discuss its impact on the meltblown structure. In the experimental range studied, fiber orientation and diameter distribution are significantly impacted by the parameters. Among these parameters. the fiber stream approach angle shows the highest effect on fiber orientation distribution. DA - 2002/12// PY - 2002/12// DO - 10.1177/004051750207201201 VL - 72 IS - 12 SP - 1033-1040 SN - 0040-5175 ER - TY - JOUR TI - Mathematical methods in imaging AU - Hero, AO AU - Krim, H T2 - IEEE SIGNAL PROCESSING MAGAZINE DA - 2002/9// PY - 2002/9// DO - 10.1109/MSP.2002.1028348 VL - 19 IS - 5 SP - 13-14 SN - 1053-5888 ER - TY - CHAP TI - Image comparison measure for digital still color cameras AU - Ramanath, A. R AU - Snyder, B. W. AU - Hinks, C. D. T2 - 2002 International Conference on Image Processing: proceedings: ICIP: 22-25 September, 2002, Rochester Riverside Convention Center, Rochester, New York, USA: Vol. 1 PY - 2002/// VL - 1 SP - 629-632 PB - Piscataway, NJ: IEEE ER - TY - JOUR TI - Focused local learning with wavelet neural networks AU - Rying, EA AU - Bilbro, GL AU - Lu, JC T2 - IEEE TRANSACTIONS ON NEURAL NETWORKS AB - A novel objective function is presented that incorporates both local and global errors as well as model parsimony in the construction of wavelet neural networks. Two methods are presented to assist in the minimization of this objective function, especially the local error term. First, during network initialization, a locally adaptive grid is utilized to include candidate wavelet basis functions whose local support addresses the local error of the local feature set. This set can be either user-defined or determined using information derived from the wavelet transform modulus maxima representation. Next, during the network construction, a new selection procedure based on a subspace projection operator is presented to help focus the selection of wavelet basis functions to reduce the local error. Simulation results demonstrate the effectiveness of these methodologies in minimizing local and global error while maintaining model parsimony and incurring a minimal increase on computational complexity. DA - 2002/3// PY - 2002/3// DO - 10.1109/72.991417 VL - 13 IS - 2 SP - 304-319 SN - 1045-9227 KW - local error KW - objective function KW - wavelets ER - TY - JOUR TI - Er-doped AlGaAs native oxides: Photoluminescence characterization and process optimization AU - Kou, LG AU - Hall, DC AU - Strohhofer, C AU - Polman, A AU - Zhang, T AU - Kolbas, RM AU - Heller, RD AU - Dupuis, RD T2 - IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS AB - We present 300 K photoluminescence (PL) characterization data for wet thermal native oxides of Al/sub 0.58/Ga/sub 0.42/As films grown by metal organic chemical vapor deposition and doped with Er via multiple high-energy ion implants (for 0.0675, 0.135, and 0.27 atomic percent (at.%) peak Er concentrations), and Al/sub 0.5/Ga/sub 0.5/As and Al/sub 0.8/In/sub 0.2/As films doped with Er (0.03-0.26 at.%) during molecular beam epitaxy crystal growth. Broad spectra with a /spl sim/50-nm full-width at half-maximum and a PL peak at 1.534 /spl mu/m are observed, characteristic of Al/sub 2/O/sub 3/:Er films. The dependencies of PL intensity, spectra, and lifetime on annealing temperature (675/spl deg/C-900/spl deg/C), time (2-60 min) and As overpressure (0-0.82 atm) are studied to optimize the annealing process, with As considered as a possible quenching mechanism. Wet and dry-oxidized films are compared to explore the role of hydroxyl (OH) groups identified by Fourier transform infrared (FTIR) spectroscopy. FTIR experiments employing heavy water (D/sub 2/O) suggest that OH groups in wet oxidized AlGaAs come mainly from post-oxidation adsorption of atmospheric moisture. AlGaAs:Er films wet oxidized with 0.1% O/sub 2/ added to the N/sub 2/ carrier gas show a fourfold PL intensity increase, doubled PL lifetime to /spl tau//spl sim/5.0 ms (0.27 at.% implanted sample), and the lowest degree of concentration quenching. DA - 2002/// PY - 2002/// DO - 10.1109/JSTQE.2002.801689 VL - 8 IS - 4 SP - 880-890 SN - 1077-260X KW - aluminum alloys KW - erbium KW - integrated optoelectronics KW - materials processing KW - optical amplifiers KW - oxidation KW - photoluminescence KW - semiconductor films ER - TY - JOUR TI - Computer-aided design of RF and microwave circuits and systems AU - Steer, MB AU - Bandler, JW AU - Snowden, CM T2 - IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES AB - The history of RF and microwave computer-aided engineering is documented in the annals of the IEEE Microwave Theory and Techniques Society. The era began with elaborate analytically based models of microwave components and simple computer-aided techniques to cascade, cascode, and otherwise connect linear component models to obtain the responses of linear microwave circuits. Development has become rapid with computer-oriented microwave practices addressing complex geometries and with the ability to globally model and optimize large circuits. The pursuit of accurate models of active devices and of passive components continues to be a key activity. DA - 2002/3// PY - 2002/3// DO - 10.1109/22.989983 VL - 50 IS - 3 SP - 996-1005 SN - 1557-9670 KW - circuit theory KW - computer-aided design KW - device modeling KW - EM modeling KW - global modeling KW - microwave circuits KW - nonlinear analysis KW - optimization ER - TY - JOUR TI - An adaptive receiver for space-time trellis codes based on per-survivor processing AU - Cozzo, C AU - Hughes, BL T2 - IEEE TRANSACTIONS ON COMMUNICATIONS AB - An adaptive receiver based on per-survivor processing is proposed for detecting space-time trellis codes transmitted over time-selective flat-fading channels, and its performance is examined through simulations. Results suggest that the new receiver can outperform iterative approaches based on Kalman filtering and the expectation-maximization algorithm, at the cost of increased receiver complexity. DA - 2002/8// PY - 2002/8// DO - 10.1109/TCOMM.2002.801457 VL - 50 IS - 8 SP - 1213-1216 SN - 1558-0857 KW - channel tracking KW - fading channels KW - joint detection and estimation KW - per-survivor processing KW - space-time coding KW - transmit diversity ER - TY - JOUR TI - X-ray and Raman analyses of GaN produced by ultrahigh-rate magnetron sputter epitaxy AU - Park, M AU - Maria, JP AU - Cuomo, JJ AU - Chang, YC AU - Muth, JF AU - Kolbas, RM AU - Nemanich, RJ AU - Carlson, E AU - Bumgarner, J T2 - APPLIED PHYSICS LETTERS AB - Thick films of GaN were studied by x-ray diffraction and Raman spectroscopy. The GaN thick films were deposited on (0001) sapphire using ultrahigh-rate magnetron sputter epitaxy with typical growth rates as high as 10–60 μm/min. The width of the x-ray rocking curve from the (0002) reflection for the sample produced by this technique is ∼300 arcsec, which is unprecedented for GaN produced by a sputtering-type process. Our recent sample shows an x-ray rocking curve width of 240 arcsec. Only allowed modes were observed in the polarized Raman spectra. The background free carrier concentration is lower than 3×1016 cm−3. The phonon lifetime of the Raman E2(2) mode of the sputtered GaN was comparable to that of bulk single crystal GaN grown by sublimation. The quality of the film was uniform across the wafer. The film was thermally stable upon annealing in N2 ambient. The x-ray and Raman analyses revealed that the sputtered GaN films are of high crystalline quality. DA - 2002/9/2/ PY - 2002/9/2/ DO - 10.1063/1.1506781 VL - 81 IS - 10 SP - 1797-1799 SN - 0003-6951 ER - TY - JOUR TI - Voltage-controlled generation of high-frequency coherent acoustic phonons in superlattices AU - Glavin, B.A. AU - Kochelap, V.A. AU - Linnik, T.L. AU - Kim, K.W. AU - Stroscio, M.A. T2 - Physica E: Low-dimensional Systems and Nanostructures AB - Abstract We demonstrate that doped superlattices in the hopping conduction regime can be used for efficient generation of high-frequency coherent acoustic phonons. The phonons that can be generated in actual finite-length superlattice structures lay at the edge of the phonon miniband and have vanishingly small radiation losses. This causes onset of the phonon generation in a relatively narrow range of Stark splitting (or electric bias) which is complemented by a peak of the current–voltage characteristic of superlattice. DA - 2002/1// PY - 2002/1// DO - 10.1016/S1386-9477(01)00330-7 VL - 12 IS - 1-4 SP - 458-461 J2 - Physica E: Low-dimensional Systems and Nanostructures LA - en OP - SN - 1386-9477 UR - http://dx.doi.org/10.1016/S1386-9477(01)00330-7 DB - Crossref KW - coherent phonons KW - generation of phonons KW - hopping conduction ER - TY - JOUR TI - Structure and properties of nanocrystalline zinc films AU - Narayan, J AU - Venkatesan, RK AU - Kvit, A T2 - JOURNAL OF NANOPARTICLE RESEARCH DA - 2002/6// PY - 2002/6// DO - 10.1023/A:1019925315398 VL - 4 IS - 3 SP - 265-269 SN - 1572-896X KW - nanocrystalline zinc films KW - Hall-Petch hardening KW - inverse Hall-Petch and softening KW - self-assembly processing KW - nanoscale characterization ER - TY - JOUR TI - Problems in publishing accurate color in IEEE journals AU - Vrhel, MJ AU - Trussell, HJ T2 - IEEE TRANSACTIONS ON IMAGE PROCESSING AB - To demonstrate the performance of color image processing algorithms, it is desirable to be able to accurately display color images in archival publications. In poster presentations, the authors have substantial control of the printing process, although little control of the illumination. For journal publication, the authors must rely on professional intermediaries (printers) to accurately reproduce their results. Our previous work describes requirements for accurately rendering images using your own equipment. This paper discusses the problems of dealing with intermediaries and offers suggestions for improved communication and rendering. DA - 2002/4// PY - 2002/4// DO - 10.1109/TIP.2002.999671 VL - 11 IS - 4 SP - 373-376 SN - 1941-0042 KW - color reproduction KW - display and printing ER - TY - JOUR TI - Multiscale signal enhancement: Beyond the normality and independence assumption AU - He, Y AU - Krim, H T2 - IEEE TRANSACTIONS ON IMAGE PROCESSING AB - Current approaches to denoising or signal enhancement in a wavelet-based framework have generally relied on the assumption of normally distributed perturbations. In practice, this assumption is often violated and sometimes prior information of the probability distribution of a noise process is not even available. To relax this assumption, we propose a novel nonlinear filtering technique in this paper. The key idea is to project a noisy signal onto a wavelet domain and to suppress wavelet coefficients by a mask derived from curvature extrema in its scale space representation. For a piecewise smooth signal, it can be shown that filtering by this curvature mask is equivalent to preserving the signal pointwise Hölder exponents at the singular points and lifting its smoothness elsewhere. DA - 2002/4// PY - 2002/4// DO - 10.1109/TIP.2002.999676 VL - 11 IS - 4 SP - 423-433 SN - 1057-7149 KW - Holder space KW - multiscale analysis KW - nonlinear filtering KW - wavelet ER - TY - JOUR TI - Lower bounds on precedence-constrained scheduling for parallel processors AU - Baev, ID AU - Meleis, WM AU - Eichenberger, A T2 - INFORMATION PROCESSING LETTERS AB - We consider two general precedence-constrained scheduling problems that have wide applicability in the areas of parallel processing, high performance compiling, and digital system synthesis. These problems are intractable so it is important to be able to compute tight bounds on their solutions. A tight lower bound on makespan scheduling can be obtained by replacing precedence constraints with release and due dates, giving a problem that can be efficiently solved. We demonstrate that recursively applying this approach yields a bound that is provably tighter than other known bounds, and experimentally shown to achieve the optimal value at least 90.3% of the time over a synthetic benchmark. We compute the best known lower bound on weighted completion time scheduling by applying the recent discovery of a new algorithm for solving a related scheduling problem. Experiments show that this bound significantly outperforms the linear programming-based bound. We have therefore demonstrated that combinatorial algorithms can be a valuable alternative to linear programming for computing tight bounds on large scheduling problems. DA - 2002/7/16/ PY - 2002/7/16/ DO - 10.1016/S0020-0190(01)00303-9 VL - 83 IS - 1 SP - 27-32 SN - 1872-6119 KW - scheduling KW - parallel processing KW - lower bounds ER - TY - JOUR TI - Fractional Levy motion and its application to network traffic modeling AU - Laskin, N AU - Lambadaris, I AU - Harmantzis, FC AU - Devetsikiotis, M T2 - COMPUTER NETWORKS AB - We introduce a general non-Gaussian, self-similar, stochastic process called the fractional Levy motion (fLm). We formally expand the family of traditional fractal network traffic models, by including the fLm process. The main findings are the probability density function of the fLm process, several scaling results related to a single-server infinite buffer queue fed by fLm traffic, e.g., scaling of the queue length, and its distribution, scaling of the queuing delay when independent fLm streams are multiplexed, and an asymptotic lower bound for the probability of overflow (decreases hyperbolically as a function of the buffer size). DA - 2002/10/22/ PY - 2002/10/22/ DO - 10.1016/s1389-1286(02)00300-6 VL - 40 IS - 3 SP - 363-375 SN - 1872-7069 KW - self-similarity KW - heavy-tailed distribution KW - scaling KW - fractal queueing theory ER - TY - JOUR TI - Direct formation of self-assembled nanoporous aluminium oxide on SiO2 and Si substrates AU - Cai, AL AU - Zhang, HY AU - Hua, H AU - Zhang, ZB T2 - NANOTECHNOLOGY AB - An unconventional self-assembly process was integrated with traditional silicon microfabrication technologies to directly form hexagonally ordered nanoporous patterns on both SiO2 and Si surfaces. Starting with an aluminium thin film deposited on a SiO2 or Si substrate, an Al anodization process was employed to generate highly uniform nanoporous anodic aluminium oxide thin films with average pore diameters of 30–70 nm directly on SiO2 and Si surfaces. The long-range order of the anodic aluminium oxide nanoporous structures was improved by thermally annealing the starting Al films to promote the grain size growth and by utilizing a multiple anodization process to enhance their uniformity. The formation of the hexagonally ordered nanoporous array may be attributed to the interplay between the topological requirement for space filling of pores and the kinetics of domain growth with time under a constant anodization voltage. These results demonstrate the feasibility of integrating self-assembled anodic aluminium oxide nanostructures with Si microfabrication technologies in the pursuit of future-generation Si nanoelectronic devices. DA - 2002/10// PY - 2002/10// DO - 10.1088/0957-4484/13/5/317 VL - 13 IS - 5 SP - 627-630 SN - 1361-6528 ER - TY - JOUR TI - Capacitance and conductance characterization of ferrocene-containing self-assembled monolayers on silicon surfaces for memory applications AU - Li, QL AU - Mathur, G AU - Homsi, M AU - Surthi, S AU - Misra, V AU - Malinovskii, V AU - Schweikart, KH AU - Yu, LH AU - Lindsey, JS AU - Liu, ZM AU - Dabke, RB AU - Yasseri, A AU - Bocian, DF AU - Kuhr, WG T2 - APPLIED PHYSICS LETTERS AB - Self-assembled monolayers of 4-ferrocenylbenzyl alcohol attached to silicon provided the basis for electrolyte-molecule-silicon capacitors. Characterization by conventional capacitance and conductance techniques showed very high capacitance and conductance peaks near ∼0.6 V associated with charging and discharging of electrons into and from discrete levels in the monolayer owing to the presence of the redox-active ferrocenes. The reversible charge trapping of these molecules suggest their potential application in memory devices. Due to the molecular scalability and low-power operation, molecular-silicon hybrid devices may be strong candidates for next-generation electronic devices. DA - 2002/8/19/ PY - 2002/8/19/ DO - 10.1063/1.1500781 VL - 81 IS - 8 SP - 1494-1496 SN - 0003-6951 ER - TY - JOUR TI - Stochastic differential equations and geometric flows AU - Unal, G AU - Krim, H AU - Yezzi, A T2 - IEEE TRANSACTIONS ON IMAGE PROCESSING AB - In previous years, curve evolution, applied to a single contour or to the level sets of an image via partial differential equations, has emerged as an important tool in image processing and computer vision. Curve evolution techniques have been utilized in problems such as image smoothing, segmentation, and shape analysis. We give a local stochastic interpretation of the basic curve smoothing equation, the so called geometric heat equation, and show that this evolution amounts to a tangential diffusion movement of the particles along the contour. Moreover, assuming that a priori information about the shapes of objects in an image is known, we present modifications of the geometric heat equation designed to preserve certain features in these shapes while removing noise. We also show how these new flows may be applied to smooth noisy curves without destroying their larger scale features, in contrast to the original geometric heat flow which tends to circularize any closed curve. DA - 2002/12// PY - 2002/12// DO - 10.1109/TIP.2002.804568 VL - 11 IS - 12 SP - 1405-1416 SN - 1057-7149 KW - geometric image and shape flows KW - stochastic differential equations KW - nonlinear filtering KW - shape analysis ER - TY - JOUR TI - Retinal prosthesis for the blind AU - Margalit, E. AU - Maia, M. AU - Weiland, J. D. AU - Greenberg, R. J. AU - Fujii, G. Y. AU - Torres, G. AU - Piyathaisere, D. V. AU - O'Hearn, T. M. AU - Liu, W. T. AU - Lazzi, G. AU - Dagnelie, G. AU - Scribner, D. A. AU - De Juan, E. AU - Humayun, M. S. T2 - Survey of Ophthalmology AB - Most of current concepts for a visual prosthesis are based on neuronal electrical stimulation at different locations along the visual pathways within the central nervous system. The different designs of visual prostheses are named according to their locations (i.e., cortical, optic nerve, subretinal, and epiretinal). Visual loss caused by outer retinal degeneration in diseases such as retinitis pigmentosa or age-related macular degeneration can be reversed by electrical stimulation of the retina or the optic nerve (retinal or optic nerve prostheses, respectively). On the other hand, visual loss caused by inner or whole thickness retinal diseases, eye loss, optic nerve diseases (tumors, ischemia, inflammatory processes etc.), or diseases of the central nervous system (not including diseases of the primary and secondary visual cortices) can be reversed by a cortical visual prosthesis. The intent of this article is to provide an overview of current and future concepts of retinal and optic nerve prostheses. This article will begin with general considerations that are related to all or most of visual prostheses and then concentrate on the retinal and optic nerve designs. The authors believe that the field has grown beyond the scope of a single article so cortical prostheses will be described only because of their direct effect on the concept and technical development of the other prostheses, and this will be done in a more general and historic perspective.. DA - 2002/// PY - 2002/// DO - 10.1016/S0039-6257(02)00311-9 VL - 47 IS - 4 SP - 335-356 ER - TY - JOUR TI - Generation of high-frequency coherent acoustic phonons in superlattices under hopping transport. II. Steady-state phonon population and electric current in generation regime AU - Glavin, B. A. AU - Kochelap, V. A. AU - Linnik, T. L. AU - Kim, K. W. AU - Stroscio, M. A. T2 - Physical Review B AB - For electrically biased superlattices exhibiting the effect of phonon instability (see paper I), we analyze the nonlinear problem of high-frequency acoustic phonon generation. We develop a theory treating self-consistently phonon generation and electron transport through the superlattice. We find that the dominant mechanism associated with the steady-state generation regime is electron heating caused by the nonequilibrium phonons. It is shown that under the generation regime the spectral distribution of phonons is extremely narrow, and that the generated power density can be as high as ${10}^{6} \mathrm{W}/{\mathrm{m}}^{2}$ for terahertz phonons. The electric current is controlled by the nonequilibrium phonons, and is higher by an order of magnitude than that under subthreshold conditions. In addition, we conclude that for the real superlattice structures the threshold condition is likely to be reached for the miniband-edge phonons having zero group velocity and negligible radiation losses. DA - 2002/1/30/ PY - 2002/1/30/ DO - 10.1103/physrevb.65.085304 VL - 65 IS - 8 SP - J2 - Phys. Rev. B LA - en OP - SN - 0163-1829 1095-3795 UR - http://dx.doi.org/10.1103/PhysRevB.65.085304 DB - Crossref ER - TY - JOUR TI - Electrical characteristics of TaSixNy/SO2/Si structures by Fowler-Nordheim current analysis AU - Suh, YS AU - Heuss, GP AU - Misra, V T2 - APPLIED PHYSICS LETTERS AB - In this letter, the Fowler–Nordheim tunneling in TaSixNy/SiO2/p-Si structures has been analyzed. The effective barrier height at the metal–oxide interface was extracted by Fowler–Nordheim current analysis. The barrier height was found to increase with increased annealing temperature. The barrier height was correlated with the extracted work function from capacitance–voltage analysis. This indicated that the work function of TaSixNy films changes under high temperature annealing from 4.2∼4.3 eV after 400 °C anneals to ∼4.8 eV after 900 °C anneals. We believe that the mechanism that causes the work function to increase is the formation of a Ta-disilicide layer at the interface between the electrode and the dielectric. DA - 2002/2/25/ PY - 2002/2/25/ DO - 10.1063/1.1453478 VL - 80 IS - 8 SP - 1403-1405 SN - 0003-6951 ER - TY - JOUR TI - An experimental study of algorithms for weighted completion time scheduling AU - Baev, ID AU - Meleis, WM AU - Eichenberger, A T2 - ALGORITHMICA DA - 2002/5// PY - 2002/5// DO - 10.1007/s00453-001-0103-x VL - 33 IS - 1 SP - 34-51 SN - 0178-4617 KW - experimental evaluation KW - weighted completion time scheduling KW - precedence constraints KW - parallel machines KW - compilers ER - TY - JOUR TI - THz-frequency intrinsic oscillations in double-barrier quantum well systems AU - Woolard, D AU - Zhao, P AU - Cui, HL T2 - PHYSICA B-CONDENSED MATTER AB - Traditional implementations of double-barrier quantum well structures (DBQWSs) have not been successful as oscillator sources at THz frequencies because they are utilized in an extrinsic (i.e., external charge exchange) manner. Indeed, the true failing of a “traditional” DBQWS-based oscillator is tied directly to the physical principles associated with its implementation. In this paper, greater insight into the physics of instabilities within nanoscale tunneling structures is revealed. Here, self-consistent, time-dependent Wigner–Poisson simulations demonstrate sustained THz-frequency current-oscillations in a DBQWS that arise without the benefit of external charging processes. More importantly, dependencies between the emitter-boundary structure and the DBQWS are identified that strongly influence the internal instability phenomenon. These new results offer potential methodologies for inducing and controlling intrinsic oscillations in DBQWSs. DA - 2002/3// PY - 2002/3// DO - 10.1016/S0921-4526(01)01372-2 VL - 314 IS - 1-4 SP - 108-112 SN - 1873-2135 KW - terahertz frequency KW - oscillator KW - quantum well KW - Wigner function ER - TY - JOUR TI - Threshold control policies for heterogeneous server systems AU - Luh, HP AU - Viniotis, I T2 - MATHEMATICAL METHODS OF OPERATIONS RESEARCH DA - 2002/3// PY - 2002/3// DO - 10.1007/s001860100168 VL - 55 IS - 1 SP - 121-142 SN - 1432-2994 KW - queueing KW - Linear Programming KW - Dynamic Programming KW - Markov processes ER - TY - JOUR TI - Phonons in nanostructures: device applications AU - Stroscio, M. AU - Dutta, M. AU - Kahn, D. AU - Kim, K.W. AU - Komirenko, S. T2 - Physica B: Condensed Matter AB - This review highlights the utility of the dielectric and elastic continuum models for describing phonons in nanostructures. The properties of confined, interface and propagating modes in wurtzite quantum-confined structures may be described theoretically in terms of the dielectric continuum and Loudon's model for uniaxial semiconductors. Moreover, dimensionally confined acoustic phonon modes in nanostructures and carbon nanotubes may be described in terms of the elastic continuum models. DA - 2002/5// PY - 2002/5// DO - 10.1016/s0921-4526(02)00418-0 VL - 316-317 SP - 8-11 J2 - Physica B: Condensed Matter LA - en OP - SN - 0921-4526 UR - http://dx.doi.org/10.1016/S0921-4526(02)00418-0 DB - Crossref KW - elastic continuum models KW - confined phonons KW - nanostructures KW - wurtzites KW - fullereness KW - carbon nanotubes ER - TY - JOUR TI - Enhanced low-temperature thermionic field emission from surface-treated N-doped diamond films AU - Kock, FAM AU - Garguilo, JM AU - Brown, B AU - Nemanich, RJ T2 - DIAMOND AND RELATED MATERIALS AB - Nitrogen-doped diamond films have been synthesized for application as a low-temperature thermionic field-emission cathode. The critical result of this study is the observation of uniform electron emission from UV photo-excitation and from thermionic field emission for films terminated with hydrogen or a 0.3-nm Ti layer. The samples were imaged with photoelectron emission microscopy (PEEM) and thermionic field-emission electron microscopy (T-FEEM) at temperatures up to 900 °C, and the electron emission current was recorded vs. the applied voltage. Hydrogen-passivated films show enhanced electron emission, but become unstable at elevated temperatures, while Ti-terminated films showed similar enhanced emission at temperatures up to 950 °C. Temperature-dependent I/V measurements show strongly increased electron emission at higher temperatures, suggesting that electron emission originates from the conduction band. These results indicate a promising new material for the production of low-temperature, high-brightness electron sources. DA - 2002/// PY - 2002/// DO - 10.1016/S0925-9635(02)00006-7 VL - 11 IS - 3-6 SP - 774-779 SN - 1879-0062 KW - chemical vapor deposition (CVD) KW - diamond KW - field emission ER - TY - JOUR TI - Effect of H-2 on nitrogen incorporation in the metalorganic chemical vapor deposition of GaAs1-yNy (0 <= y <= 0.08) AU - Moody, BF AU - Barletta, PT AU - El-Masry, NA AU - Roberts, JC AU - Aumer, ME AU - LeBoeuf, SF AU - Bedair, SM T2 - APPLIED PHYSICS LETTERS AB - The effect of hydrogen on the incorporation of nitrogen in GaAs1−yNy grown by metalorganic chemical vapor deposition (MOCVD) is reported. Nitrogen content as high as y=0.081 has been achieved when the use of H2 is completely avoided in the MOCVD growth of GaAs1−yNy. When H2 is added to the growth ambient, the value of y in GaAs1−yNy decreases as the relative percent of H2 in the carrier gas increases. We will report on the properties of these GaAsN films and discuss the nature of the effect that H2 has on modulating the N content in these films. DA - 2002/4/8/ PY - 2002/4/8/ DO - 10.1063/1.1464225 VL - 80 IS - 14 SP - 2475-2477 SN - 0003-6951 ER - TY - JOUR TI - Confinement and amplification of terahertz acoustic phonons in cubic heterostructures AU - Komirenko, S.M. AU - Kim, K.W. AU - Kochelap, V.A. AU - Stroscio, M.A. T2 - Physica B: Condensed Matter AB - A general criterion for phonon confinement is derived in the model of elastically anisotropic (cubic) media. The results are applied to the calculation of the dispersion curves of the confined phonons in Si/Si1−xGex/Si and AlAs/GaAs/AlAs heterostructures. For these structures, we show that the lowest-order phonon branches behave differently from those in the model of isotropic media. We have found that confinement is strong in the terahertz frequency range. For p-Si/SiGe/Si and n-AlAs/GaAs/AlAs quantum well heterostructures, we have studied the effect of amplification of confined high-frequency phonons by the drift of low-dimensional carriers. Two electron–phonon interaction mechanisms were taken into account: interaction via the deformation potential (p-SiGe and n-AlGaAs) and the piezoelectric interaction (n-AlGaAs). It was found that an amplification coefficient of the order of 102cm−1 for the AlGaAs heterostructures and 103cm−1 for the SiGe heterostructures can be obtained in spectrally-separated narrow amplification bands. DA - 2002/5// PY - 2002/5// DO - 10.1016/S0921-4526(02)00506-9 VL - 316-317 SP - 356-358 J2 - Physica B: Condensed Matter LA - en OP - SN - 0921-4526 UR - http://dx.doi.org/10.1016/S0921-4526(02)00506-9 DB - Crossref KW - acoustic phonon confinement KW - phonon amplification KW - elastic anisotropy ER - TY - JOUR TI - Computing call-blocking probabilities in LEO satellite networks: The single-orbit case AU - Zaim, AH AU - Rouskas, GN AU - Perros, HG T2 - IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY AB - We study the problem of carrying voice calls over a low-Earth-orbit satellite network and present an analytical model for computing call-blocking probabilities for a single orbit of a satellite constellation. We have devised a method to solve the corresponding Markov process efficiently for orbits of up to five satellites. For orbits consisting of a larger number of satellites, we have developed an approximate decomposition algorithm to compute the call-blocking probabilities by decomposing the system into smaller subsystems and iteratively solving each subsystem in isolation using the exact Markov process. Our approach can capture blocking due to handoffs for both satellite-fixed and Earth-fixed constellations. Numerical results demonstrate that our method is accurate for a wide range of traffic patterns and for orbits with a number of satellites that is representative of commercial satellite systems. DA - 2002/3// PY - 2002/3// DO - 10.1109/25.994809 VL - 51 IS - 2 SP - 332-347 SN - 1939-9359 KW - call blocking probability KW - decomposition algorithms KW - handoffs KW - low-earth-orbit (LEO) satellite networks ER - TY - JOUR TI - Choosing the brain(s) of an embedded system AU - Conte, TM T2 - COMPUTER AB - Embedded processors are fundamentally different from desktop processors -costs are too tight for fancy chip sets and expensive packaging. So if you're new to embedded processors, the marketplace is foreign. Worse, so are the design decisions. When you consider purchasing an embedded microprocessor, look carefully at the direct memory access engine. DA - 2002/7// PY - 2002/7// DO - 10.1109/MC.2002.1016908 VL - 35 IS - 7 SP - 106-107 SN - 0018-9162 ER - TY - JOUR TI - Observation of latent reliability degradation in ultrathin oxides after heavy-ion irradiation AU - Suehle, JS AU - Vogel, EM AU - Roitman, P AU - Conley, JF AU - Johnston, AH AU - Wang, B AU - Bernstein, JB AU - Weintraub, CE T2 - APPLIED PHYSICS LETTERS AB - Constant voltage time-dependent-dielectric-breakdown distributions were obtained for both unirradiated and irradiated 3.0 and 3.2 nm thick SiO2 films subjected to Co60 gamma irradiation and heavy ions of 823 MeV Xe129 (linear energy transfer=59 MeV-cm2/mg). The gamma irradiation had no effect on oxide lifetime. The heavy ion irradiation substantially reduced oxide life even though the devices were biased at 0.0 V during irradiation. The reduction of oxide lifetime under constant-voltage stress conditions was a strong function of the heavy ion fluence. DA - 2002/2/18/ PY - 2002/2/18/ DO - 10.1063/1.1448859 VL - 80 IS - 7 SP - 1282-1284 SN - 1077-3118 ER - TY - JOUR TI - Guest Editorial - Multiuser detection techniques with application to wired and wireless communications systems II AU - Cherubini, G AU - Cioffi, JM AU - Duel-Hallen, A AU - Poor, HV AU - Tranter, WH T2 - IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS DA - 2002/2// PY - 2002/2// DO - 10.1109/JSAC.2002.983334 VL - 20 IS - 2 SP - 233-236 SN - 0733-8716 ER - TY - JOUR TI - Electron-beam-induced optical memory effects in GaN AU - Chang, YC AU - Cai, AL AU - Johnson, MAL AU - Muth, JF AU - Kolbas, RM AU - Reitmeier, ZJ AU - Einfeldt, S AU - Davis, RF T2 - APPLIED PHYSICS LETTERS AB - Metastable effects in unintentionally doped GaN films grown on SiC substrates have been investigated using cathodoluminescence (CL). Memory effect patterns produced optically are observed in CL images. An electron beam can also produce memory effect patterns and the resulting changes in the luminescence spectra are quite similar for either optical or electron-beam-induced patterns. CL spectra reveal that the yellow luminescence at 2.2 eV increases significantly with little change in the band-edge emission in both cases. Samples that do not exhibit optically induced memory effects are also investigated and do not exhibit electron-beam-induced patterns, either. Monochromatic CL images at 540 and 365 nm confirm the similarity of optically and electron-beam-induced memory effects based on changes in luminescence spectra. DA - 2002/4/15/ PY - 2002/4/15/ DO - 10.1063/1.1469222 VL - 80 IS - 15 SP - 2675-2677 SN - 0003-6951 ER - TY - JOUR TI - Effects of tensile, compressive, and zero strain on localized states in AlInGaN/InGaN quantum-well structures AU - Aumer, ME AU - LeBoeuf, SF AU - Moody, BF AU - Bedair, SM AU - Nam, K AU - Lin, JY AU - Jiang, HX T2 - APPLIED PHYSICS LETTERS AB - The recombination dynamics of optical transitions as well as strain effects in AlInGaN/In0.08Ga0.92N quantum wells (QWs) were studied. QW emission energy, photoluminescence decay behavior, photoluminescence emission line shape, and nonradiative recombination behavior were found to be strong functions of strain as well as localization. The degree of carrier localization was inferred by modeling several aspects of optical behavior obtained from variable temperature time-resolved photoluminescence experiments. According to the modeling results, the degree of localization was found to be a minimum for unstrained QWs and increased as either tensile or compressive strain increased, indicating that InGaN QW microstructure is a function of the lattice-mismatch-induced strain experienced during deposition. DA - 2002/4/29/ PY - 2002/4/29/ DO - 10.1063/1.1469219 VL - 80 IS - 17 SP - 3099-3101 SN - 0003-6951 ER - TY - JOUR TI - Designing a heterostructure for the quantum receiver AU - Kiselev, A. A. AU - Kim, K. W. AU - Yablonovitch, E. T2 - Applied Physics Letters AB - In this letter, we develop optimal parameters for a structure which is suitable for the realization of a coherent quantum receiver. Conditions including predefined photon wavelength, strain, small Zeeman splitting of the electron levels, and large Zeeman effect for quantum-confined light holes are satisfied simultaneously for the structure based on the InGaAsP solid solutions. We are able to achieve designs with wavelengths of 1.3 and 1.55 μm that are desirable for optoelectronic applications. DA - 2002/4/22/ PY - 2002/4/22/ DO - 10.1063/1.1472480 VL - 80 IS - 16 SP - 2857-2859 J2 - Appl. Phys. Lett. LA - en OP - SN - 0003-6951 1077-3118 UR - http://dx.doi.org/10.1063/1.1472480 DB - Crossref ER - TY - JOUR TI - Confinement and amplification of acoustic waves in cubic heterostructures AU - Komirenko, S. M. AU - Kim, K. W. AU - Kochelap, V. A. AU - Stroscio, M. A. T2 - Physical Review B AB - We present the theory of acoustic phonon confinement in elastically anisotropic (cubic) quantum-well (QW) heterostructures grown in a direction of high symmetry. A general criterion for phonon confinement is derived. For ${\mathrm{S}\mathrm{i}/\mathrm{S}\mathrm{i}}_{0.5}{\mathrm{Ge}}_{0.5}/\mathrm{Si},$ $\mathrm{S}\mathrm{i}/\mathrm{G}\mathrm{e}/\mathrm{S}\mathrm{i}$ and $\mathrm{A}\mathrm{l}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}/\mathrm{A}\mathrm{l}\mathrm{A}\mathrm{s}$ QW heterostructures, dispersion curves are obtained, and displacement fields corresponding to the confined phonons are studied in detail. It is found that the confinement of acoustic phonons in these QW layers is strong in the subterahertz and terahertz frequency ranges. The resulting description of phonon confinement is applied to analyze the amplification of confined modes by the drift of the two-dimensional carriers as a function of the phonon frequency, the temperature, and the parameters of heterostructure. The calculation shows that the amplification coefficient of the confined phonons can exceed ${10}^{3} {\mathrm{cm}}^{\ensuremath{-}1}$ for Si/Ge-based structures and ${10}^{2} {\mathrm{cm}}^{\ensuremath{-}1}$ for AlAs/GaAs-based structures. DA - 2002/4/4/ PY - 2002/4/4/ DO - 10.1103/physrevb.65.155321 VL - 65 IS - 15 SP - J2 - Phys. Rev. B LA - en OP - SN - 0163-1829 1095-3795 UR - http://dx.doi.org/10.1103/PhysRevB.65.155321 DB - Crossref ER - TY - JOUR TI - A robust multilevel interconnect module for subquartermicrometer complementary metal oxide semiconductor technology integration AU - Zhang, ZB AU - Huang, JS AU - Twiford, M AU - Martin, E AU - Layadi, N AU - Salah, A AU - Bhowmik, B AU - Vitkavage, D AU - Lytle, S AU - Yeh, ECC AU - Tu, KN T2 - JOURNAL OF THE ELECTROCHEMICAL SOCIETY AB - In this work, we present detailed studies of two integration schemes for an aluminum-wire/tungsten-plug-based multilevel ultralarge scale integration (ULSI) interconnect module for subquartermicrometer complementary metal oxide semiconductor (CMOS) technologies, and discuss the benefits and drawbacks of each of them primarily from a process integration point of view. We demonstrate that an etch stop (ES) integration scheme in which the via etch stops on the TiN cladding layer could result in significantly improved via electromigration performance compared to an over etch (OE) integration scheme in which the via is overetched into the underlying Al(Cu). We also identified several highly detrimental early failure modes associated with the OE structure, including contamination-induced stress void formation underneath the via, the metal extrusion inside the via, and the metal corrosion at the bottom of the via, and showed that such early failure modes could be prevented in the ES integration scheme. Even though there were some small penalties in the device performance in the ES integration scheme, the benefits in the reliability and the better tolerance to manufacturing process variation clearly justify the adoption of this robust multilevel ULSI interconnect module for subquartermicrometer CMOS technologies. © 2002 The Electrochemical Society. All rights reserved. DA - 2002/5// PY - 2002/5// DO - 10.1149/1.1467949 VL - 149 IS - 5 SP - G324-G329 SN - 1945-7111 ER - TY - PAT TI - System and method for powering, controlling, and communicating with multiple inductively-powered devices AU - Mueller, J. S. AU - Nagle, H. T. AU - Gyurcsik, R. S. AU - Kelley, A. W. C2 - 2002/// DA - 2002/// PY - 2002/// ER - TY - JOUR TI - Reliability degradation of ultra-thin oxynitride and Al2O3 gate dielectric films owing to heavy-ion irradiation AU - Choi, B. K. AU - Fleetwood, D. M. AU - Massengill, L. W. AU - Schrimpf, R. D. AU - Galloway, K. F. AU - Shaneyfelt, M. R. AU - Meisenheimer, T. L. AU - Dodd, P. E. AU - Schwank, J. R. AU - Lee, Y. M. AU - Johnson, R. S. AU - Lucovsky, G. T2 - Electronics Letters AB - The charge-to-breakdown of 3.3 nm oxynitride films shows significant degradation after irradiation with 342 MeV Au ions. In contrast, 5.4 nm Al2O3 films exhibit much less degradation for similar heavy-ion stress. DA - 2002/// PY - 2002/// DO - 10.1049/el:20020119 VL - 38 IS - 4 SP - 157-158 ER - TY - JOUR TI - Theory of nanotip formation AU - Bilbro, G. L. T2 - Journal of Vacuum Science & Technology. B, Microelectronics and Nanometer Structures DA - 2002/// PY - 2002/// VL - 20 IS - 3 SP - 757-761 ER - TY - JOUR TI - The effects of timing jitter and tracking on the performance of impulse radio AU - Lovelace, WM AU - Townsend, JK T2 - IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS AB - Impulse radio (IR) is a promising ultra-wideband technique for tactical military communications. A key feature of time-hopping IR are the very narrow pulses used to convey information. Analysis of such time-hopping schemes under a variety of assumptions have been reported in the literature. However, none of these studies to date consider the effects of timing jitter and tracking on time-hopping in a ultra-wideband (UWB) setting. We consider the effects of timing jitter and tracking on the performance of binary and 4-ary UWB communications. We find that the performance of IR is very sensitive to timing jitter and tracking, at least in part due to the very narrow pulses. We also find that in the presence of timing jitter and tracking, orthogonal 4-ary pulse position modulation (PPM) out performs binary offset PPM at all jitter levels in thermal and pulse noise. Simulation results are presented that quantify the sensitivity of binary and 4-ary IR to timing jitter and tracking error. DA - 2002/12// PY - 2002/12// DO - 10.1109/JSAC.2002.805058 VL - 20 IS - 9 SP - 1646-1651 SN - 1558-0008 KW - impulse radio (IR) KW - medium access control (MAC) layer KW - network KW - timing jitter KW - tracking KW - ultra-wideband (UWB) radio KW - wireless ER - TY - JOUR TI - Self and sovereignty: Individual and community in South Asian Islam since 1850 AU - Gilmartin, D T2 - INDIAN ECONOMIC AND SOCIAL HISTORY REVIEW DA - 2002/// PY - 2002/// DO - 10.1177/001946460203900414 VL - 39 IS - 4 SP - 458-460 SN - 0019-4646 ER - TY - JOUR TI - Queue control under time-variant delays: A discrete time system approach AU - Bauer, P. H. AU - Sichitiu, Mihail L. AU - Premaratne, K. T2 - Journal of Circuits, Systems, and Computers AB - This paper introduces a discrete time model for time-variant delays and investigates the very nature of such delays. It is shown that a linear system-delay interface is a system theoretic necessity for the construction of composite linear systems with time-variant delays. Based on this analysis, two interfaces of particular importance are presented and used to obtain new, simple to check stability results for queue control systems. The relevance of the presented modeling and stability results on queue control systems to QoS control in modern communication networks is illustrated via several examples. DA - 2002/// PY - 2002/// DO - 10.1142/s0218126602000380 VL - 11 IS - 2 SP - 187–211 ER - TY - JOUR TI - Nanocell logic gates for molecular computing AU - Tour, JM AU - Van Zandt, WL AU - Husband, CP AU - Husband, SM AU - Wilson, LS AU - Franzon, PD AU - Nackashi, DP T2 - IEEE TRANSACTIONS ON NANOTECHNOLOGY AB - Molecular electronics seeks to build electrical devices to implement computation - logic and memory - using individual or small collections of molecules. These devices have the potential to reduce device size and fabrication costs, by several orders of magnitude, relative to conventional CMOS. However, the construction of a practical molecular computer will require the molecular switches and their related interconnect technologies to behave as large-scale diverse logic, with input/output wires scaled to molecular dimensions. It is unclear whether it is necessary or even. possible to control the precise regular placement and interconnection of these diminutive molecular systems. This paper describes genetic algorithm-based simulations of molecular device structures in a nanocell where placement and connectivity of the internal molecular switches are not specifically directed and the internal topology is generally disordered. With some simplifying assumptions, these results show that it is possible to use easily fabricated nanocells as logic devices by setting the internal molecular switch states after the topological molecular assembly is complete. Simulated logic devices include an inverter, a NAND gate, an XOR gate and a 1-bit adder. Issues of defect and fault tolerance are addressed. DA - 2002/6// PY - 2002/6// DO - 10.1109/TNANO.2002.804744 VL - 1 IS - 2 SP - 100-109 SN - 1536-125X KW - circuit simulation KW - genetic algorithms KW - logic circuit fault tolerance KW - logic devices KW - molecular electronics ER - TY - JOUR TI - A high-linearity 100-element diode grid mixer AU - Oliveira, M. AU - Cheung, C. D. M. AU - Al-Zayed, A. AU - Chio, I. F. F. AU - Swisher, R. R. AU - Lecuyer, F. AU - Delisio, M. P. T2 - IEEE Transactions on Antennas and Propagation AB - Grid-mixer arrays can achieve high linearity and dynamic range through quasi-optical power combining. We present a 100-element single-ended diode grid mixer operating at 2.45 GHz. Each element incorporates two diodes in series. We measure an input third-order intercept of 11 W (40.5 dBm), and output third-order intercept of 3.4 W (35.4 dBm), and an associated conversion loss of 5.1 dB. The power-handling capability of the array is 100 times larger than that of a microstrip mixer using a single element. The local oscillator (LO) drive requirement for the entire array is 1.4 W (31.6 dBm). The angular dependence of the array's IF power is also presented and is in agreement with theory. DA - 2002/// PY - 2002/// DO - 10.1109/TAP.2002.1011237 VL - 50 IS - 5 SP - 698-702 ER - TY - JOUR TI - Unifying probabilistic and variational estimation AU - Hamza, AB AU - Krim, H AU - Unal, GB T2 - IEEE SIGNAL PROCESSING MAGAZINE AB - A maximum a posteriori (MAP) estimator using a Markov or a maximum entropy random field model for a prior distribution may be viewed as a minimizer of a variational problem.Using notions from robust statistics, a variational filter referred to as a Huber gradient descent flow is proposed. It is a result of optimizing a Huber functional subject to some noise constraints and takes a hybrid form of a total variation diffusion for large gradient magnitudes and of a linear diffusion for small gradient magnitudes. Using the gained insight, and as a further extension, we propose an information-theoretic gradient descent flow which is a result of minimizing a functional that is a hybrid between a negentropy variational integral and a total variation. Illustrating examples demonstrate a much improved performance of the approach in the presence of Gaussian and heavy tailed noise. In this article, we present a variational approach to MAP estimation with a more qualitative and tutorial emphasis. The key idea behind this approach is to use geometric insight in helping construct regularizing functionals and avoiding a subjective choice of a prior in MAP estimation. Using tools from robust statistics and information theory, we show that we can extend this strategy and develop two gradient descent flows for image denoising with a demonstrated performance. DA - 2002/9// PY - 2002/9// DO - 10.1109/MSP.2002.1028351 VL - 19 IS - 5 SP - 37-47 SN - 1053-5888 ER - TY - JOUR TI - The partitions of memory: The afterlife of the division of India AU - Gilmartin, D T2 - INDIAN ECONOMIC AND SOCIAL HISTORY REVIEW DA - 2002/// PY - 2002/// DO - 10.1177/001946460203900106 VL - 39 IS - 1 SP - 115-117 SN - 0019-4646 ER - TY - JOUR TI - Spin relaxation of conduction electrons in bulk III-V semiconductors AU - Song, Pil Hun AU - Kim, K. W. T2 - Physical Review B AB - The spin relaxation time of conduction electrons through the Elliot-Yafet, D'yakonov-Perel, and Bir-Aronov-Pikus mechanisms is calculated theoretically for bulk GaAs, GaSb, InAs, and InSb of both n and p type. The relative importance of each spin relaxation mechanism is compared, and diagrams showing the dominant mechanism are constructed as a function of the temperature and impurity concentration. Our approach is based upon theoretical calculations of the momentum relaxation rate, and allows one to understand the interplay between various factors affecting the spin relaxation over a broad range of temperature and impurity concentration. DA - 2002/7/31/ PY - 2002/7/31/ DO - 10.1103/physrevb.66.035207 VL - 66 IS - 3 SP - J2 - Phys. Rev. B LA - en OP - SN - 0163-1829 1095-3795 UR - http://dx.doi.org/10.1103/PhysRevB.66.035207 DB - Crossref ER - TY - PCOMM TI - Mathematics for demosaicking AU - Trussell, HJ AU - Hartwig, RE AB - Digital color cameras sample the continuous color spectrum using three or more filters; however, each pixel represents a sample of only one of the color bands. This arrangement is called a mosaic. To produce a full-resolution color image, the recorded image must be processed to estimate the values of the pixels for all the other color bands. This restoration process is often called demosaicking. This paper uses stacked notation to represent the mosaicked image capture and derives the minimum mean square error (MMSE) estimator for the demosaicked image. By making common assumptions, the restoration can be computed in a cost-effective manner. Extensions to the linear method are proposed to allow adaptive behavior. DA - 2002/4// PY - 2002/4// DO - 10.1109/tip.2002.999681 SP - 485-492 KW - deblurring KW - demosaic KW - digital camera KW - image restoration KW - interpolation ER - TY - JOUR TI - Issues in high-kappa gate stack interfaces AU - Misra, V AU - Lucovsky, G AU - Parsons, GN T2 - MRS BULLETIN DA - 2002/3// PY - 2002/3// DO - 10.1557/mrs2002.73 VL - 27 IS - 3 SP - 212-216 SN - 1938-1425 KW - gate stacks KW - high-dielectric-constant materials KW - high-kappa dielectrics KW - interface reactions KW - metal gates ER - TY - JOUR TI - Hot electrons in group-III nitrides at moderate electric fields AU - Barry, E. A. AU - Kim, K. W. AU - Kochelap, V. A. T2 - Applied Physics Letters AB - By the use of the Monte Carlo method, we studied the distribution function and the basic characteristics of hot electrons in InN, GaN, and AlN under moderate electric fields. We found that in relatively low fields (of the order of kV/cm) the optical phonon emission dominates in the electron kinetics. This strongly inelastic process gives rise to a spindle-shaped distribution function and an extended portion of a quasisaturation of the current–voltage (I–V) characteristics (the streaming-like regime). Formation of this regime is induced by a suppression of the electron spreading over the momenta perpendicular to the electric field. We prove that this is a universal character of the hot electron behavior for all three nitrides. The effects can be detected by the measurement of the I–V characteristics, or the thermopower of hot electrons in the transverse direction. DA - 2002/4// PY - 2002/4// DO - 10.1063/1.1464666 VL - 80 IS - 13 SP - 2317-2319 J2 - Appl. Phys. Lett. LA - en OP - SN - 0003-6951 1077-3118 UR - http://dx.doi.org/10.1063/1.1464666 DB - Crossref ER - TY - JOUR TI - Fuzzy neural network models for liquefaction prediction AU - Rahman, MS AU - Wang, J T2 - SOIL DYNAMICS AND EARTHQUAKE ENGINEERING AB - Integrated fuzzy neural network models are developed for the assessment of liquefaction potential of a site. The models are trained with large databases of liquefaction case histories. A two-stage training algorithm is used to develop a fuzzy neural network model. In the preliminary training stage, the training case histories are used to determine initial network parameters. In the final training stage, the training case histories are processed one by one to develop membership functions for the network parameters. During the testing phase, input variables are described in linguistic terms such as ‘high’ and ‘low’. The prediction is made in terms of a liquefaction index representing the degree of liquefaction described in fuzzy terms such as ‘highly likely’, ‘likely’, or ‘unlikely’. The results from the model are compared with actual field observations and misclassified cases are identified. The models are found to have good predictive ability and are expected to be very useful for a preliminary evaluation of liquefaction potential of a site for which the input parameters are not well defined. DA - 2002/9// PY - 2002/9// DO - 10.1016/S0267-7261(02)00059-3 VL - 22 IS - 8 SP - 685-694 SN - 0267-7261 KW - earthquake KW - soil KW - liquefaction KW - ground failure KW - fuzzy neural network models ER - TY - JOUR TI - Demosaicking methods for Bayer color arrays AU - Ramanath, R AU - Snyder, WE AU - Bilbro, GL AU - Sander, WA T2 - JOURNAL OF ELECTRONIC IMAGING AB - The Journal of Electronic Imaging (JEI), copublished bimonthly with the Society for Imaging Science and Technology, publishes peer-reviewed papers that cover research and applications in all areas of electronic imaging science and technology. DA - 2002/7// PY - 2002/7// DO - 10.1117/1.1484495 VL - 11 IS - 3 SP - 306-315 SN - 1560-229X ER - TY - JOUR TI - Transmission of longitudinal optical phonons through a barrier in uniaxial crystals AU - Lee, B. C. AU - Yu, SeGi AU - Kim, K. W. AU - Stroscio, M. A. AU - Dutta, M. T2 - Physical Review B AB - Transmission of longitudinal optical (LO) phonons in double heterostructures with uniaxial anisotropy is investigated within a dielectric continuum model. When LO-like phonons are generated in the left semi-infinite layer, their transmission probability through a barrier to the right semi-infinite layer is calculated. ${\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{N}/\mathrm{GaN}/{\mathrm{In}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{N}$ and $\mathrm{GaN}/{\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{N}/\mathrm{GaN}$ systems are considered for numerical calculations. In contrast to the isotropic case, where there is no transmission, it is shown that the propagation probability could be significant with only about 1% anisotropy. The propagation probability of phonons is found to increase with increasing wavelength of the LO-like phonon for a given barrier width. DA - 2002/4/15/ PY - 2002/4/15/ DO - 10.1103/physrevb.65.153315 VL - 65 IS - 15 SP - J2 - Phys. Rev. B LA - en OP - SN - 0163-1829 1095-3795 UR - http://dx.doi.org/10.1103/PhysRevB.65.153315 DB - Crossref ER -