TY - CHAP TI - Optical Packet Switching (OPS) AU - Rouskas, G.N. AU - Xu, L. T2 - Optical Networks A2 - Sivalingam, Krishna A2 - Subramanian, Suresh PY - 2006/6/15/ DO - 10.1007/0-387-29188-1_17 SP - 797–843 PB - Kluwer Academic Publishers SN - 0387290559 UR - http://dx.doi.org/10.1007/0-387-29188-1_17 ER - TY - JOUR TI - Dynamic Wavelength Sharing Policies for Absolute QoS in OBS Networks AU - Yang, Li AU - Rouskas, George N. AU - IEEE T2 - Globecom 2006 - 2006 Ieee Global Telecommunications Conference DA - 2006/// PY - 2006/// ER - TY - JOUR TI - Adaptive path selection in OBS networks AU - Yang, Li AU - Rouskas, George N. T2 - Journal of Lightwave Technology AB - In this paper, the authors investigate the concept of adaptive path selection in optical burst-switched networks and its potential to reducing the overall burst drop probability. Specifically, the authors assume that each source maintains a (short) list of alternate paths to each destination and uses information regarding the recent congestion status of the network links to rank the paths; it then transmits bursts along the least congested path. The authors present a suite of path selection strategies, each utilizing a different type of information regarding the link congestion status, and evaluate them using simulation. The results demonstrate that, in general, adaptive path selection outperforms shortest path routing, and, depending on the path strategy involved, the network topology, and the traffic pattern, this improvement can be significant. A new framework for the development of hybrid (or meta) path selection strategies, which make routing decisions based on a weighted combination of the decisions taken by several independent path selection strategies, has been presented. This paper presents two instances of such hybrid strategies, i.e., 1) one that assigns static weights and 2) one that dynamically adjusts the weights based on feedback from the network; it has been shown that these strategies can further improve the overall burst drop probability in the network. DA - 2006/// PY - 2006/// DO - 10.1109/JLT.2006.878087 VL - 24 IS - 8 SP - 3002-3011 ER - TY - JOUR TI - A framework for absolute QoS guarantees in optical burst switched networks AU - Yang, Li AU - Rouskas, George N. AU - IEEE T2 - 2006 3rd International Conference on Broadband Communications, Networks and Systems, Vols 1-3 DA - 2006/// PY - 2006/// SP - 1-10 ER - TY - CONF TI - Integrating Production Planning and Safety Stock Determination AU - Uzsoy, R. AU - Ravindran, A. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - CONF TI - Integrated Production Planning and Pricing with Congestion-Prone Production Resources AU - Upasani, A. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - CONF TI - Multiproduct Dynamic Lot Sizing with Work in Process and Congestion AU - Hwang, S. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - CONF TI - A Common Modeling Framework for Transportation and Production Planning Problems with Congestion Phenomena AU - Kalafatas, G. AU - Peeta, S. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - CONF TI - A Genetic Algorithm for a Single Product Network Design Model with Lead Time and Safety Stock Considerations AU - Sourirajan, K. AU - Ozsen, L. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - CONF TI - A Multi-Product Break-Bulk Network Design Model with Lead Time and Safety Stock Considerations AU - Sourirajan, K. AU - Ozsen, L. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - SOUND TI - From Engineering the System to Engineering Information AU - Deshmukh, A. AU - Uzsoy, R. DA - 2006/2// PY - 2006/2// ER - TY - CONF TI - Heuristics for Scheduling a Single Machine with Family Dependent Setup Times AU - Uzsoy, R. AU - Velasquez, J.D. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - CONF TI - Scheduling Engineering and Production Lots in Wafer Fabrication AU - Crist, K. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - CONF TI - Juggling Tasks: Mine, Yours and Ours... AU - Mendez, L.I. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 2006/11// CY - Pittsburgh, PA DA - 2006/11// PY - 2006/11// ER - TY - ER - TY - JOUR TI - A Problem Reduction Approach for Scheduling Semiconductor Wafer Fabrication Facilities AU - Upasani, A.A. AU - Uzsoy, R. AU - Sourirajan, K. T2 - IEEE Transactions on Semiconductor Manufacturing AB - Most scheduling procedures used in industry are based on the dispatching paradigm, where decisions are made based on the jobs available at the time the machine becomes free. While optimization-based scheduling procedures have repeatedly been shown to yield significantly better schedules under ideal circumstances, their practical implementation is hampered by high computational requirements. We present a problem reduction procedure that allows a workcenter-based global scheduling heuristic to be implemented in very low CPU times. The procedure partitions the workcenters in a fab into heavily loaded and lightly loaded classes and solves the global scheduling problem only for the heavily loaded workcenters. The proposed technique is tested on instances drawn from an International SEMATECH wafer fab model. The proposed problem reduction approach yields superior results with modest computational effort, enabling the practical use of the decomposition heuristic. DA - 2006/5// PY - 2006/5// DO - 10.1109/tsm.2006.873510 VL - 19 IS - 2 SP - 216-225 J2 - IEEE Trans. Semicond. Manufact. LA - en OP - SN - 0894-6507 UR - http://dx.doi.org/10.1109/tsm.2006.873510 DB - Crossref KW - empirical testing KW - heuristic decomposition KW - scheduling ER - TY - JOUR TI - Tractable Nonlinear Production Planning Models for Semiconductor Wafer Fabrication Facilities AU - Asmundsson, J. AU - Rardin, R.L. AU - Uzsoy, R. T2 - IEEE Transactions on Semiconductor Manufacturing AB - We describe a simulation study of a production planning model for multistage production inventory systems that reflects the nonlinear relationship between resource utilization and lead time. The model is based on the use of clearing functions that capture the nonlinear relationship between workload and throughput. We show how these clearing functions can be estimated from empirical data using a simulation model as a surrogate for observation of the production system under study. We then examine the sensitivity of the estimated clearing function to different dispatching algorithms, different demand patterns, and production planning techniques. Computational experiments based on a scaled-down model of a semiconductor wafer fabrication facility illustrate the potential benefits of the clearing function model relative to conventional linear programming models. DA - 2006/2// PY - 2006/2// DO - 10.1109/tsm.2005.863214 VL - 19 IS - 1 SP - 95-111 J2 - IEEE Trans. Semicond. Manufact. LA - en OP - SN - 0894-6507 UR - http://dx.doi.org/10.1109/tsm.2005.863214 DB - Crossref KW - cycle times KW - linear programming KW - production planning KW - wafer fabrication ER - TY - JOUR TI - Low-level exertions of the neck musculature: A study of research methods AU - Joines, Sharon M.B. AU - Sommerich, Carolyn M. AU - Mirka, Gary A. AU - Wilson, James R. AU - Moon, Samuel D. T2 - Journal of Electromyography and Kinesiology AB - Musculoskeletal neck discomfort is prevalent in many occupations and has been the focus of much research employing surface electromyography (sEMG). Significant differences in experimental methods among researchers make comparisons across studies difficult. The goal of the current research was to use empirical methods to answer specific methodological questions concerning use of sEMG in evaluation of the neck extensor system. This was accomplished in two studies. In Experiment 1, ultrasound technology was used to: (a) determine accessibility of m. splenius and semispinalis capitis with surface electrodes, (b) identify appropriate electrode locations for these muscles/muscle groups, and (c) illustrate potential benefits of using ultrasound in locating muscles/placing electrodes. Experiment 2 sought to assess effects of posture when normalizing sEMG data. Results from Experiment 1 showed no direct access to semispinalis capitis for surface electrodes; their activity can only be sampled as part of a group of muscles. In most subjects, m. splenius was found to be accessible to surface electrodes. Electrode placement recommendations are provided. Results of Experiment 2 showed significant differences in normalized EMG data between a posture-specific technique and a reference posture technique. Posture-specific normalization is recommended for accurately assessing the relative intensity of contractions of these muscles. DA - 2006/10// PY - 2006/10// DO - 10.1016/j.jelekin.2005.09.007 VL - 16 IS - 5 SP - 485-497 J2 - Journal of Electromyography and Kinesiology LA - en OP - SN - 1050-6411 UR - http://dx.doi.org/10.1016/j.jelekin.2005.09.007 DB - Crossref KW - electrode location KW - normalization method KW - muscle access KW - neck muscles ER - TY - CONF TI - Computationally Efficient Models of Urban and Natural Terrain by Non-iterative Domain Decomposition for L1 Smoothing Splines AU - Fang, S. AU - Lin, Y.-M. AU - Zhang, Y. AU - Lavery, J. E. T2 - 25th Army Science Conference C2 - 2006/12// C3 - Proceedings of the 25th Army Science Conference DA - 2006/12// PY - 2006/12// ER - TY - JOUR TI - Cubic L1 Splines on Triangulated Irregular Networks AU - Zhang, W. AU - Fang, S. AU - Wang, Y. AU - Lavery, J.E. T2 - Pacific Journal of Optimization DA - 2006/// PY - 2006/// VL - 2 IS - 2 SP - 289–317 ER - TY - JOUR TI - Capacity Allocation and Inventory Policy in a Distribution System AU - Dai, Yue AU - Chao, Xiuli AU - Fang, Shu Cherng AU - Nuttle, Henry L. W. T2 - Asia-Pacific Journal of Operational Research AB - We consider a single-period distribution system with one supplier and two retailers. The supplier may have infinite or finite capacity. The demand at each retailer is random. When a stockout occurs at one retailer the customer may go to the other retailer. We study both the decentralized and centralized inventory control problems. For the decentralized problem we show that a unique Nash equilibrium exists when the capacity at the supplier is infinite. However, when the capacity is finite, only under certain conditions does the Nash equilibrium exist. For centralized inventory control we obtain the optimal allocation that maximizes the expected profit of the entire supply chain. For the case of decentralized controls we also design channel coordination mechanisms, i.e., a decentralized cost structure resulting in a Nash equilibrium with chain-wide profits equal to those achieved under a fully centralized system. We compare the performance of two retailers in the decentralized and centralized controls and analyze the impact of channel coordination on the whole supply chain. DA - 2006/12// PY - 2006/12// DO - 10.1142/s0217595906001054 VL - 23 IS - 04 SP - 543–571 SN - 0217-5959 1793-7019 UR - http://dx.doi.org/10.1142/s0217595906001054 KW - game theory KW - supply chain management KW - channel coordination KW - capacity allocation problem ER - TY - JOUR TI - Efficient numerical methods for the 2D nonlinear Poisson–Boltzmann equation modeling charged spheres AU - Li, Zhilin AU - Qiao, Zhong-hua AU - Tang, Tao T2 - Journal of Computational Mathematics DA - 2006/// PY - 2006/// VL - 24 IS - 3 SP - 252–264 ER - TY - CONF TI - Active Incipient Failure Detection: A Nonlinear Case Study AU - Drake, K.J. AU - Campbell, S.L. AU - Andjelkovic, I. AU - Sweetingham, K. T2 - 4th International Conference on Computing, Communications and Control Technologies: CCCT '06 C2 - 2006/// C3 - Proceedings of the 4th International Conference on Computing, Communications and Control Technologies: CCCT '06 CY - Orlando, FL DA - 2006/// PY - 2006/7/20/ ER - TY - MGZN TI - New ideas for SIAM conferences from Europe AU - Ipsen, I.C.F. T2 - SIAM News DA - 2006/12// PY - 2006/12// VL - 39 SP - 5 M1 - 10 ER - TY - JOUR TI - Towards supply chain collaboration: An operations audit of VMI initiatives in the electronics industry AU - Blackhurst, J. AU - Craighead, C.W. AU - Handfield, R.B. T2 - International Journal of Integrated Supply Management AB - Recently, there has been an increased focus on supply chain collaboration efforts such as Vendor-Managed Inventory (VMI). Often, supply chain partners have experienced gaps between desired and actual performance in working towards a successful collaborative relationship. In this research, we analysed two VMI initiatives that have not yet produced the level of performance desired by the supply chain partners involved. In each case, an operations audit was performed to determine where characteristic and performance gaps existed. The output of this research effort is inherent in the operations audit process employed, the VMI initiative gaps discovered during the process as well as the steps that could be undertaken to minimise or eliminate these gaps. The paper culminates in a framework that describes the operations audit in terms of an iterative, collaboration evaluation process. The framework and process can serve as valuable mechanisms for understanding the evolution towards collaborative supply chain relationships. DA - 2006/// PY - 2006/// DO - 10.1504/IJISM.2006.008340 VL - 2 IS - 1-2 SP - 91-105 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33644509533&partnerID=MN8TOARS ER - TY - JOUR TI - Managing conflict of interest issues in purchasing AU - Handfield, R.B. AU - Baumer, D.L. T2 - Journal of Supply Chain Management AB - SUMMARY One of the most important elements of ethical purchasing behavior is conflict of interest. In response to the heightened regulatory environment, many organizations have initiated reviews of their conflict of interest policies and ethical codes of behavior in supply management. The goal of the current exploratory study is to determine the most common approaches used to promote compliance with ethical codes of conduct (specifically conflict of interest policies) in supply management. Questionnaires were administered to eight “typical” Fortune 500 companies. Current conflicts of interest policies were identified, in addition to spotlighting common approaches to enforcing ethical behavior, including multiple communication and reporting channels, formal procedures, effective sanctions against violators and regular training of employees in ethical policies. Survey results were used to generate a scoring system that compares the overall level of ethics management maturity based on profiles of the companies studied in the research. DA - 2006/// PY - 2006/// DO - 10.1111/j.1745-493X.2006.00016.x VL - 42 IS - 3 SP - 41-50 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33745835070&partnerID=MN8TOARS ER - TY - CONF TI - Dynamic Multidrug Therapies for HIV: Feedback and Structured Treatment Interruption Control Approaches AU - Tran, H. AU - Banks, H.T. AU - David, John AU - Toivanen, J.A. AU - Kwon, Hae-Dae T2 - 17th International Symposium on Mathematical Theory of Networks and Systems C2 - 2006/// C3 - MTNS 2006 : proceedings of the 17th international symposium on mathematical theory of networks and systems, Kyoto, Japan, 24-28.07.2006. CY - Kyoto International Conference Hall, Kyoto, Japan DA - 2006/// PY - 2006/7/24/ PB - Kyoto University ER - TY - CONF TI - Experimenting with Real-Time ATIS: Stepping Forward fromADVANCE AU - Demers, Alixandra AU - List, George F. AU - Wojtowicz, Jeffrey AU - Kornhauser, Alain AU - Wallace, Al AU - Lee, Earl E. AU - Salasznyk, Paul T2 - Ninth International Conference on Applications of Advanced Technology in Transportation (AATT) AB - In the early 1990's, an in-vehicle navigation and route guidance project called ADVANCE was conducted in the northeastern suburbs of Chicago. It proved that travel time data could be updated on in-vehicle devices (albeit not in real-time) to assist drivers in choosing faster routes to their destinations. This past spring, about a decade later, a more progressive but similar 3-month field experiment was conducted in upstate New York. Nearly 200 participants used state-of-the-art, in-vehicle navigation and route guidance technology in conjunction with GPS tracking and broadband wireless to share travel time data and pick the shortest paths through a congested network. The route guidance devices observed travel times, uploaded them to a central server that updated a travel time database, and then downloaded every minute to each of the probe vehicles to ensure the latest travel time information was being used while enroute. The experiment resulted in a total of 4,111,210 latitude-longitude position/ speed/ time points. The largest number of location points per user was 98,018 while the smallest was 117; the average per user was just over 26,000 location points, or 325.5 points per trip. There were 12,629 probe trips for a traveled distance of 147,316 miles over a duration of 3,945.8 hours. This paper presents a discussion of the Capital District ATIS project including the parallels and differences with the ADVANCE effort. Areas covered are: travel time data, project background, description of the study area, participant statistics, experiment design, sample results, and a summary with future research directions. C2 - 2006/8/4/ C3 - Applications of Advanced Technology in Transportation DA - 2006/8/4/ DO - 10.1061/40799(213)51 PB - American Society of Civil Engineers SN - 9780784407998 UR - http://dx.doi.org/10.1061/40799(213)51 DB - Crossref ER - TY - CONF TI - Strategic safety stock placement in production networks with supply risk AU - Warsing, D.P. AU - Helmer, E.A. AU - Blackhurst, J.V. C2 - 2006/// C3 - 2006 IIE Annual Conference and Exhibition DA - 2006/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-36448975542&partnerID=MN8TOARS ER - TY - JOUR TI - Logistics planning under uncertainty for disposition of radioactive wastes AU - List, George F. AU - Wood, Bryan AU - Turnquist, Mark A. AU - Nozick, Linda K. AU - Jones, Dean A. AU - Lawton, Craig R. T2 - Computers & Operations Research AB - The US Department of Energy (DOE) faces an enormous environmental remediation challenge involving highly radioactive wastes at former weapons production facilities. The purpose of this analysis is to focus on equipment acquisition and fleet sizing issues related to transportation of wastes from remediation sites to disposal sites. Planning for the transportation of these wastes must be done with recognition of important uncertainties related to overall quantities of waste to be moved, the rate at which the wastes will be prepared for transport, and the certification of suitable transportation containers for use in the effort. However, deadlines for completion of the effort have already been set by the political process, without much regard for these uncertainties. To address this fleet sizing problem, we have created a robust optimization model that focuses on equipment investment decisions. Through this robust optimization, we illustrate how modeling can be used to explore the effects of uncertainty on the equipment acquisition strategy. The disposition of radioactive wastes from DOE sites is an important illustration of a category of problems where equipment investments must be made under conditions of considerable uncertainty. The methodology illustrated in this paper can be applied to this general class of problems. DA - 2006/3// PY - 2006/3// DO - 10.1016/j.cor.2004.07.017 VL - 33 IS - 3 SP - 701-723 J2 - Computers & Operations Research LA - en OP - SN - 0305-0548 UR - http://dx.doi.org/10.1016/j.cor.2004.07.017 DB - Crossref ER - TY - CONF TI - A modified ALA procedure for logistic network designs with scale economies AU - Bucci, M.J. AU - Kay, M.G. C2 - 2006/// C3 - 2006 IIE Annual Conference and Exhibition DA - 2006/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84858473880&partnerID=MN8TOARS ER - TY - CONF TI - Supply chain multi-objective simulation optimization AU - Joines, J.A. AU - Thoney, K.A. AU - King, R.E. AU - Kay, M.G. C2 - 2006/// C3 - 4th International Industrial Simulation Conference 2006, ISC 2006 DA - 2006/// SP - 377-383 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84898422528&partnerID=MN8TOARS ER - TY - RPRT TI - All-Integer Dual Simplex for Binate Cover Problems (Draft) AU - Stallmann, M. DA - 2006/// PY - 2006/// DO - ER - TY - JOUR TI - Rapid Modeling and Discovery of Priority Dispatching Rules: An Autonomous Learning Approach AU - Geiger, Christopher D. AU - Uzsoy, Reha AU - Aytuğ, Haldun T2 - Journal of Scheduling DA - 2006/2// PY - 2006/2// DO - 10.1007/s10951-006-5591-8 VL - 9 IS - 1 SP - 7-34 J2 - J Sched LA - en OP - SN - 1094-6136 1099-1425 UR - http://dx.doi.org/10.1007/s10951-006-5591-8 DB - Crossref KW - priority dispatching rules KW - single machine KW - rule discovery KW - genetic programming ER - TY - CHAP TI - Locally Invertible Multivariate Polynomial Matrices AU - Lobo, Ruben G. AU - Bitzer, Donald L. AU - Vouk, Mladen A. T2 - Coding and Cryptography AB - A new class of rectangular zero prime multivariate polynomial matrices are introduced and their inverses are computed. These matrices are ideal for use in multidimensional systems involving input-output transformations. We show that certain multivariate polynomial matrices, when transformed to the sequence space domain, have an invertible subsequence map between their input and output sequences. This invertible subsequence map can be used to derive the polynomial inverse matrix together with a set of pseudo-inverses. All computations are performed using elementary operations on the ground field without using any polynomial operations. PY - 2006/// DO - 10.1007/11779360_33 SP - 427-441 OP - PB - Springer Berlin Heidelberg SN - 9783540354819 9783540354826 UR - http://dx.doi.org/10.1007/11779360_33 DB - Crossref ER - TY - CONF TI - Applications of Robust Failure Detection Algorithms to Power Systems AU - Drake, K.J. AU - Campbell, S.L. AU - Andjelkovic, I.V. AU - Hannas, B.L. AU - Sweetingham, K.A. T2 - 13th International Conference on, Intelligent Systems Application to Power Systems AB - As modelling and simulation become increasingly popular in the design process and as an alternative to expensive testing, fault detection methods based on model identification algorithms become more reliable as well as less expensive and easier to implement. In this paper we discuss the application of two active fault detection algorithms based on model identification to power systems. The algorithms are similar in theory though differ in implementation. The first is a direct optimization approach that handles more general systems and more varied constraints. It requires more sophisticated software but it's easily adapted to more than two models. The second algorithm is a constrained control approach that can be implemented on common math software, such as Matlab or Scilab, and handles model uncertainty. In both cases, the algorithms are free of false alarms depending upon the quality of the models used. C2 - 2006/3/21/ C3 - Proceedings of the 13th International Conference on, Intelligent Systems Application to Power Systems DA - 2006/3/21/ DO - 10.1109/isap.2005.1599275 PB - IEEE SN - 1599751747 UR - http://dx.doi.org/10.1109/isap.2005.1599275 DB - Crossref ER - TY - CONF TI - Order of Convergence in the Direct Transcription Solution of Optimal Control Problems AU - Engelsone, A. AU - Campbell, S.L. AU - Betts, J.T. T2 - 44th IEEE Conference on Decision and Control AB - In the direct transcription approach to the numerical solution of optimal control problems, the optimal control problem is discretized and the resulting nonlinear programming problem is solved numerically. There has been considerable study over the last 10 years on order of convergence of cost, state, multipliers, and control. This paper discusses these questions, and the highly technical results in the literature, in the context of their implications for industrial grade optimal control packages. C2 - 2006/10/4/ C3 - Proceedings of the 44th IEEE Conference on Decision and Control DA - 2006/10/4/ DO - 10.1109/cdc.2005.1582741 PB - IEEE SN - 0780395670 UR - http://dx.doi.org/10.1109/cdc.2005.1582741 DB - Crossref ER - TY - JOUR TI - Problems and techniques: Introduction AU - Ipsen, I.C.F. T2 - SIAM Review DA - 2006/// PY - 2006/// VL - 48 IS - 2 SP - 485-486 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33744920863&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and techniques AU - Ipsen, I. T2 - SIAM Review DA - 2006/// PY - 2006/// VL - 48 IS - 1 SP - 41-42 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33644586567&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - The Problems and Techniques section features two papers: one on differential equations, and one on sums containing binomial coefficients and their logarithms. The deflection u(x) of a beam at point x can be described by an ordinary differential equation (ODE) of fourth order, such as, for instance, $$ \hspace*{58pt}\frac{ \mbox{ \textit{d}$^{\mbox{\fontsize{6pt}{6pt}\selectfont 4}}$\textit{u}(\textit{x})}} {\mbox{ \textit{dx}$^{\mbox{\fontsize{6pt}{6pt}\selectfont 4}}$}} \mbox{ = – 100,\qquad 0 $\leq$ \textit{x} $\leq$ 1.} $$ In this specific example the vertical load on the beam is uniform, as is the bending stiffness, and the beam has length 1. A unique solution u(x) exists if appropriate boundary conditions are prescribed, e.g., u(0) = u(1) = u$^{\prime}$(0) = u$^{\prime}$(1) = 0, which means that the beam is fixed at both ends. But what if the beam isn't fixed and we don't know the boundary conditions precisely? What if we have only bounds on the deflection and rotation at the endpoints, that is, inequalities of the form –1 $\leq$ u(x) $\leq$ 1 and –1 $\leq$ u$^{\prime}$(x) $\leq$ 1 for x = 0 and x = 1? Does a solution still exist? Enrique Castillo, Antonio Conejo, Carmen Castillo, and Roberto Mínguez, in “Solving Ordinary Differential Equations with Range Conditions,” show that it does indeed. The authors present a method to determine all solutions for linear ODEs whose boundary conditions are linear and are prescribed within intervals (or ranges) rather than at single points. Based on the inequalities in the boundary conditions, they formulate a system of linear inequalities. The solutions to this system represent coefficients in a linear combination that describes all solutions of the ODE. The authors also discuss tests for existence and uniqueness of solutions. The second paper, “Difference of Sums Containing Products of Binomial Coefficients and Their Logarithms,” is concerned with the expression $$ \hspace*{59pt}\displaystyle\frac{\mbox{1}} {\mbox{2$^{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{n}}}$}} \mbox{$\displaystyle\sum_{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{k} = 0}} ^{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{n}}}$} \left(\displaystyle\frac{\mbox{1}}{\mbox{2}} \mbox{$\alpha_{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{k}}}$} \mbox{ ln } \alpha_{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{k}}}-\beta_{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{k}}} \mbox{ ln } \beta_{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{k}}} \right)\mbox{,} \qquad \mbox{$\alpha_{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{k}}}$} \equiv {\mbox{\textit{n} + 1}\choose \mbox{\textit{k}}}\mbox{,}\quad \mbox{$\beta_{\mbox{\fontsize{6pt}{6pt}\selectfont \textit{k}}}$} \equiv {\mbox{\textit{n}}\choose \mbox{\textit{k}}}\mbox{,} $$ which occurs in an analysis of covert communication channels and is related to the capacity of the covert channel. Authors Allen Miller and Ira Moskowitz use binomial identities to simplify the expression, show that it increases monotonically with n, and prove that it converges to ln 2 as n $\rightarrow \infty$. DA - 2006/1// PY - 2006/1// DO - 10.1137/siread000048000002000305000001 VL - 48 IS - 2 SP - 305-305 ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - Readers may be surprised to learn that there is something on which everybody in my department agrees: the heating system is absolutely ineffective. Some offices get too hot too fast (usually inhabitated by some who like it cold), while other offices (like mine, unfortunately) take forever to become even slightly warm. The building is heated by a network of pipes through which hot steam is circulated. Question: How to design a heating system that delivers the same amount of steam to each office as fast as possible, thereby ensuring that all offices have the same temperature as fast as possible? Answer: Construct a specific matrix, called a weighted Laplacian, and choose the weights so as to maximize its second largest eigenvalue. The weights tell us how wide each pipe needs to be. Of course, this is a constrained optimization problem, because we are on a budget and can afford only a limited amount of material for the pipes. A more general problem is discussed by Jun Sun, Stephen Boyd, Lin Xiao, and Persi Diaconis in their paper “The Fastest Mixing Markov Process on a Graph and a Connection to a Maximum Variance Unfolding Problem.” They express the problem of maximizing the second largest eigenvalue of the Laplacian as a semidefinite program. The dual of this program has a simple geometric interpretation: It’s the problem of positioning n points in n‐space, so that they are as far apart as possible, but do not exceed prescribed distances between any two points. Coming back now to the heating issues in my department, we have been promised a new building. Ground breaking is to start anytime now (or so, at least, we are told). I have been thinking about giving this paper to the architects; it might inspire them to install a more effective heating system. In the well‐written paper “Globalization Techniques for Newton–Krylov Methods and Applications to the Fully Coupled Solution of the Navier–Stokes Equations,” Roger Pawlowski, John Shadid, Joseph Simonis, and Homer Walker discuss methods for the solution of systems of nonlinear equations $F(u)=0$. Such systems arise, for instance, when one discretizes partial differential equations to solve fluid flow problems. Arguably the most popular method for solving $F(u)=0$ is Newton’s method. It starts from an initial approximation $u_0$ and produces successively better (we hope) iterates $u_{k+1}$ as updates of the previous iterate, $u_{k+1}=u_k+s_k$. The step $s_k$ is computed as the solution to the linear system $F^{\prime}(u_k)s_k=-F(u_k)$, where the Jacobian $F^{\prime}(u)$ is the matrix of derivatives. When the linear system is solved by a Krylov space method, for instance, one talks about a Newton–Krylov method. Convincing Newton’s method to converge to the solution is not always easy, especially when the initial approximation $u_0$ is far away. A variety of strategies is available that can enhance the performance of Newton’s method. The authors discuss two. To increase robustness, one can solve the linear systems more or less accurately; this is done by terminating the linear system solution as soon as the residual norm $\|F^{\prime}(u_k)+F(u_k)s_k\|$ falls below a specified forcing term. To improve the chances for convergence, one can globalize Newton’s method by changing the length of the step $s_k$ (as opposed to its direction), or by choosing a step $s_k$ that minimizes the residual norm over a particular region. The authors prove convergence results, and perform numerical experiments on standard benchmark problems to compare different forcing terms and globalization strategies. Are you one of those people who firmly believes that there is one and only one way to win a tennis match? And that’s by subjecting your opponent to that impossible‐to‐return 700‐horse‐power serve? Yes? Then we might have just the paper for you. In “Monte Carlo Tennis,” Paul Newton and Kamran Aslam analyze the probability of winning in tennis, and express it in terms of the probability that a player wins a point when serving. In previous work, Paul Newton and coauthor Joe Keller had assumed that this probability is constant—throughout the whole match, and even a tournament. This amounts to assuming that points in tennis are random variables, independently and identically distributed (i.i.d.). However, this assumption fails to account for the “hot‐hand,” when everything goes just swimmingly; the “back‐to‐the‐wall” effect, when miraculous feats become possible in the face of looming loss; or simply the adjustment to new tennis balls. Do these things really make a difference? Is the i.i.d. assumption unrealistic? Paul Newton and Kamran Asham perform Monte Carlo simulations in MATLAB to answer this question. Read the paper if you want to know what they come up with. DA - 2006/1// PY - 2006/1// DO - 10.1137/siread000048000004000679000001 VL - 48 IS - 4 SP - 679-680 ER - TY - CONF TI - Computer Optimized Gun Design AU - Ives, R. L. AU - Read, M.E. AU - Bui, Thuc AU - David, John AU - Tran, Hien T2 - >2006 Joint 31st International Conference on Infrared Millimeter Waves and 14th International Conference on Teraherz Electronics AB - Computer optimization can explore a wider parameter space than practical with manual design, particularly for 3D geometries. This allows rapid, economical development of higher performance devices. The proliferation of parametric solid modeling programs allows optimization of both geometry and operating parameters. This presentation described computer optimization in the 3D trajectory code beam optics analysis (BOA). This is possible because meshing in BOA is completely automatic, allowing the program to be controlled by the optimization routines. C2 - 2006/9// C3 - 2006 Joint 31st International Conference on Infrared Millimeter Waves and 14th International Conference on Teraherz Electronics DA - 2006/9// DO - 10.1109/icimw.2006.368358 PB - IEEE SN - 1424403995 1424404002 UR - http://dx.doi.org/10.1109/icimw.2006.368358 DB - Crossref ER - TY - JOUR TI - Stochastic portfolio optimization with log utility AU - Pang, Tao T2 - International Journal of Theoretical and Applied Finance AB - A portfolio optimization problem on an infinite time horizon is considered. Risky asset price obeys a logarithmic Brownian motion, and the interest rate varies according to an ergodic Markov diffusion process. Moreover, the interest rate fluctuation is correlated with the risky asset price fluctuation. The goal is to choose optimal investment and consumption policies to maximize the infinite horizon expected discounted log utility of consumption. A dynamic programming principle is used to derive the dynamic programming equation (DPE). The explicit solutions for optimal consumption and investment control policies are obtained. In addition, for a special case, an explicit formula for the value function is given. DA - 2006/// PY - 2006/// DO - 10.1142/s0219024906003858 VL - 9 IS - 6 SP - 869-887 SN - 0219-0249 1793-6322 UR - http://dx.doi.org/10.1142/s0219024906003858 KW - Portfolio optimization KW - dynamic programming equations KW - subsolution and supersolutions ER - TY - CONF TI - Comparison between failure detection test signals for continuous systems and sampled-data systems AU - Choe, D. AU - Campbell, S. L. AU - Nikoukhah, R. T2 - Proceedings of the 45th IEEE Conference on Decision and Control AB - In active failure detection it is essential to have auxiliary signal inputs that are capable of identifying the status of observed systems while the operations of the systems are minimally disturbed by the extra input. Recently, two signal-design-algorithms for active failure detection were introduced: one that computes optimal continuous detection signals for continuous systems (CS) and the other that designs optimal piecewise-constant signal inputs for sampled-data systems (SDS). In some applications simple piecewise constant inputs are sought. In this paper, we combine the key ideas of the two previous algorithms and present an algorithm that finds optimal piecewise-constant signals for continuous systems. This modified algorithm provides a suboptimal detection signal inputs for continuous systems and would appear to be greatly faster than the original CS algorithm. We also compare the three algorithms and the corresponding optimal signals through a computational experiment C2 - 2006/// C3 - Proceedings of the 45th IEEE Conference on Decision and Control DA - 2006/// DO - 10.1109/cdc.2006.377349 PB - IEEE SN - 1424401712 UR - http://dx.doi.org/10.1109/cdc.2006.377349 DB - Crossref ER - TY - CONF TI - Model Based Failure Detection using Test Signals from Linearizations: A Case Study AU - Campbell, S. AU - Drake, K. AU - Andjelkovic, I. AU - Sweetingham, K. AU - Choe, D. T2 - 2006 IEEE Conference on Computer-Aided Control Systems Design C2 - 2006/10// C3 - 2006 IEEE Conference on Computer-Aided Control Systems Design DA - 2006/10// DO - 10.1109/cacsd.2006.285526 PB - IEEE SN - 0780397975 UR - http://dx.doi.org/10.1109/cacsd.2006.285526 DB - Crossref ER - TY - CONF TI - Robust detection of incipient faults: an active approach AU - Nikoukhah, R. AU - Campbell, S. L. T2 - 2006 14th Mediterranean Conference on Control and Automation AB - The methodology of auxiliary signal design for robust failure detection based on multi-model formulation of normal and failed systems is used to study the problem of incipient fault detection. Here, the fault is modeled as a drift in a system parameter, and an auxiliary signal is to be designed to enhance the detection of variations in this parameter. It is shown that it is possible to consider the model of the system with a drifted parameter as a second model and use the multi-model framework for designing the auxiliary signal by considering the limiting case as the parameter variation goes to zero. The result can be applied very effectively to early detection problems where small parameter variations should be detected C2 - 2006/6// C3 - 2006 14th Mediterranean Conference on Control and Automation DA - 2006/6// DO - 10.1109/med.2006.328694 PB - IEEE SN - 0978672011 0978672003 UR - http://dx.doi.org/10.1109/med.2006.328694 DB - Crossref ER - TY - CONF TI - Trust representation and aggregation in a distributed agent system AU - Wang, Y. AU - Singh, M.P. C2 - 2006/// C3 - Proceedings of the National Conference on Artificial Intelligence DA - 2006/// VL - 2 SP - 1425-1430 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33750688177&partnerID=MN8TOARS ER - TY - CONF TI - Specifying and resolving preferences among agent interaction patterns AU - Mallya, A.U. AU - Singh, M.P. AB - A strength of commitment protocols is that they enable agents to act flexibly, thereby enabling them to accommodate varying local policies and respond to exceptions. A consequent weakness is that commitment protocols thus fail to distinguish between possible executions that are normal and those that may be allowed but are not ideal. This paper develops an approach for specifying preferences among executions that are allowed by a protocol. It captures sets of executions via an event constraint specification language and gives them a denotational characterization based on branching-time models. This paper develops algorithms for choosing the best execution path by considering the interplay between the preference specification of a protocol and local policies of agents interacting using the protocol, thereby giving the specifications a natural operational characterization. The value of the concepts developed is illustrated by its application to a recent practical framework for protocols called OWL-P. Further, the paper shows that the operational and denotational characterizations of preference specifications coincide. C2 - 2006/// C3 - Proceedings of the International Conference on Autonomous Agents DA - 2006/// DO - 10.1145/1160633.1160886 VL - 2006 SP - 1361-1368 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-34247231533&partnerID=MN8TOARS ER - TY - JOUR TI - Secure data management in reactive sensor networks T2 - Lecture Notes in Computer Science AB - A wireless sensor network (WSN), an ad hoc network of resource constrained sensor nodes, has become an attractive option for monitoring applications. The wide use of sensor networks is due to the cheap hardware and detailed information they provide to the end user. As with every network of every computing device, security is one of the key issue of sensor networks. The resource constrained nature of sensor nodes make the security quite challenging. The sensor networks are prone to many kinds of security attack viz. report fabrication attack, denial of service attack, Sybil attack, traffic analysis attack, node replication attack, physical attack etc. The report fabrication attack is a security attack in which the adversary tries to generate bogus reports by compromising the sensor nodes. This paper proposes a security solution that makes cluster based sensor networks resilient to report fabrication attacks. The proposed solution relies on symmetric key mechanisms, appropriate for random deployment and also handles the node failures. DA - 2006/// PY - 2006/// DO - 10.1007/11961635_16 UR - https://publons.com/publon/21294465/ ER - TY - CHAP TI - Producing Compliant Interactions: Conformance, Coverage, and Interoperability AU - Chopra, Amit K. AU - Singh, Munindar P. T2 - Declarative Agent Languages and Technologies IV AB - Agents in an open system interact with each other based on (typically, published) protocols. An agent may, however, deviate from the protocol because of its internal policies. Such deviations pose certain challenges: (1) the agent might no longer be conformant with the protocol—how do we determine if the agent is conformant? (2) the agent may no longer be able to interoperate with other agents—how do we determine if two agents are interoperable? (3) the agent may not be able to produce some protocol computations; in other words, it may not cover the protocol—how we determine if an agent covers a protocol?We formalize the notions of conformance, coverage and interoperability. A distinctive feature of our formalization is that the three are orthogonal to each other. Conformance and coverage are based on the semantics of runs (a run being a sequence of states), whereas interoperability among agents is based upon the traditional idea of blocking. We present a number of examples to comprehensively illustrate the orthogonality of conformance, coverage, and interoperability.Compliance is a property of an agent’s execution whereas conformance is a property of the agent’s design. In order to produce only compliant executions, first and foremost the agent must be conformant; second, it must also be able to interoperate with other agents. PY - 2006/// DO - 10.1007/11961536_1 SP - 1-15 OP - PB - Springer Berlin Heidelberg SN - 9783540689591 9783540689614 UR - http://dx.doi.org/10.1007/11961536_1 DB - Crossref ER - TY - BOOK TI - Service-Oriented Computing: Semantics, Processes, Agents AU - Singh, Munindar P. AU - Huhns, M.N. AB - Traditional approaches to software development - the ones embodied in CASE tools and modeling frameworks - are appropriate for building individual software components, but they are not designed to face the challenges of open environments. Service-oriented computing provides a way to create a new architecture that reflects components' trends toward autonomy and heterogeneity. We thus emphasize SOC concepts instead of how to deploy Web services in accord with current standards. To begin the series, we describe the key concepts and abstractions of SOC and the elements of a corresponding engineering methodology. DA - 2006/// PY - 2006/// DO - 10.1002/0470091509 PB - Chichester; Hoboken, NJ: Wiley SE - 1-549 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84947336240&partnerID=MN8TOARS ER - TY - JOUR TI - Report on the fourth international joint conference on Autonomous Agents and Multiagent Systems (AAMAS 2005) AU - Koenig, S. AU - Kraus, S. AU - Singh, M.P. AU - Wooldridge, M. T2 - AI Magazine DA - 2006/// PY - 2006/// VL - 27 IS - 1 SP - 103-107 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33645745843&partnerID=MN8TOARS ER - TY - CHAP TI - OWL-P: A Methodology for Business Process Development AU - Desai, Nirmit AU - Mallya, Ashok U. AU - Chopra, Amit K. AU - Singh, Munindar P. T2 - Agent-Oriented Information Systems III. AOIS 2005 A2 - Kolp, M. A2 - Bresciani, P. A2 - Henderson-Sellers, B. A2 - Winikoff, M. T3 - Lecture Notes in Computer Science AB - Business process modelling and enactment are notoriously complex, especially in open settings where the business partners are autonomous, requirements must be continually finessed, and exceptions frequently arise because of real-world or organizational problems. Traditional approaches, which attempt to capture processes as monolithic flows, have proved inadequate in addressing these challenges. We propose an agent-based approach for business process modelling and enactment which is centred around the concepts of commitment-based agent interaction protocols and policies. A (business) protocol is a modular, public specification of an interaction among different roles. Such protocols, when integrated with the internal business policies of the participants, yield concrete business processes. We show how this reusable, refinable and evolvable abstraction simplifies business process design and development. PY - 2006/// DO - 10.1007/11916291_6 VL - 3529 LNAI SP - 79–94 PB - Springer SN - 9783540482918 9783540482925 SV - 3529 UR - http://dx.doi.org/10.1007/11916291_6 ER - TY - CHAP TI - Introducing Preferences into Commitment Protocols AU - Mallya, Ashok U. AU - Singh, Munindar P. T2 - Agent Communication II A2 - Dignum, Frank P.M. A2 - van Eijk, Roger M. A2 - Flores, Roberto T3 - Lecture Notes in Computer Science AB - Commitment protocols enable flexibility in agent interactions by utilizing the semantics of commitments to develop succinct declarative specifications for protocols that allow a large number of executions. As a consequence, commitment protocols enable agents to accommodate varying local policies and respond to exceptions. A consequent weakness of such protocols is that commitment protocols thus fail to distinguish between possible executions that are normal and those that may be allowed but are not ideal. This paper develops an approach for specifying preferences among executions that are allowed by a protocol. It captures sets of executions via a simple language and gives them a denotational characterization based on branching-time models. It shows how to incorporate the specifications into rulesets, thereby giving the specifications a natural operational characterization. The rulesets embed into a recent practical framework for protocols called OWL-P. The paper shows that the operational and denotational characterizations coincide. PY - 2006/// DO - 10.1007/978-3-540-68143-4_10 SP - 136–149 PB - Springer SN - 9783540681427 9783540681434 SV - 3859 UR - http://dx.doi.org/10.1007/978-3-540-68143-4_10 ER - TY - CONF TI - Multiagent policy architecture for virtual business organizations AU - Udupi, Y.B. AU - Singh, M.P. AB - A virtual organization (VO) is a dynamic collection of entities (individuals, enterprises, and information resources) collaborating on some computational activity. VOs are an emerging means to model, enact, and manage large-scale service computations. VOs consist of autonomous, heterogeneous members, often exhibiting complex behaviors. Thus VOs are a natural match for policy-based approaches. Traditional policy-based frameworks emphasize reactive behaviors, wherein an external request causes a policy engine to compute a response. However, business service settings require richer policies and call for proactive behaviors. A business not only must respond to explicit requests, but also monitor its environment, collate events, and potentially act in anticipation of events in order to ensure that its policies are satisfied. Autonomous, heterogeneous, proactive entities are best modeled as agents and, therefore, VOs are best understood as multiagent systems. Our main contributions are (1) a proactive multiagent policy-based architecture, (2) a hierarchical model of policy monitoring, compliance checking, and enforcement for VOs, and (3) a formalization of VOs. We evaluate our approach using a real business service scenario C2 - 2006/// C3 - Proceedings - 2006 IEEE International Conference on Services Computing, SCC 2006 DA - 2006/// DO - 10.1109/SCC.2006.75 SP - 44-51 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-35148823347&partnerID=MN8TOARS ER - TY - BOOK TI - Introducing preferences into commitment protocols AU - Mallya, A.U. AU - Singh, M.P. DA - 2006/// PY - 2006/// VL - 3859 LNAI SE - 136-149 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-77956013565&partnerID=MN8TOARS ER - TY - JOUR TI - Interaction-oriented programming: Concepts, theories, and results on commitment protocols T2 - Lecture Notes in Computer Science AB - Unlike traditional information systems, modern systems are _open_, consisting of autonomous, heterogeneous parties interacting dynamically. Yet prevalent software techniques make few accommodations for this fundamental change. Multiagent systems are conceptualized for open environments. They give prominence to flexible reasoning and arms-length interactions captured via communications. On the backdrop of multiagent systems, Interaction-Oriented Programming is the idea of programming with interactions as first-class entities instead of, e.g., objects. Protocols are to interactions as classes are to objects: because of their key nature, protocols have obtained a lot of research attention. Modeling protocols suitably for open environments meant modeling their content, not just the surface communications. In a number of important cases, such as business processes and organizations, the content is best understood using the notion of commitments of an agent to another agent in an appropriate context. Our theory of protocols supports flexible enactment of protocols, a treatment of refinement and composition of protocols, and their relationship with organizations and contracts, thus reducing the gap between agents and conventional computer science. This talk will review the key concepts, theories, and results on commitment protocols, and some important challenges that remain.. DA - 2006/// PY - 2006/// DO - 10.1007/11941439_3 UR - https://publons.com/publon/21294469/ ER - TY - CONF TI - Contract enactment in virtual organizations: A commitment-based approach AU - Udupi, Y.B. AU - Singh, M.P. C2 - 2006/// C3 - Proceedings of the National Conference on Artificial Intelligence DA - 2006/// VL - 1 SP - 722-727 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33750708550&partnerID=MN8TOARS ER - TY - CONF TI - An overview of business process adaptations via protocols AU - Desai, N. AU - Chopra, A.K. AU - Singh, M.P. AB - Business process management in open environments poses special challenges. In particular, such environments are dynamic, thereby requiring frequent changes in business processes. Current business process modeling approaches handle such changes in an ad hoc manner, and lack a principled means of determining what needs to be changed and where.This paper provides an overview of process adaptability through a novel application of business protocols, especially of protocol composition, introduced in our previous work. Through a real business scenario of auto-insurance claim processing, this paper briefly describes how a wide range of adaptations can be handled naturally and systematically via protocol composition. The illustrated adaptations have been evaluated via a prototype. C2 - 2006/// C3 - Proceedings of the International Conference on Autonomous Agents DA - 2006/// DO - 10.1145/1160633.1160879 VL - 2006 SP - 1326-1328 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-34247252465&partnerID=MN8TOARS ER - TY - CONF TI - Contextualizing commitment protocols AU - Chopra, A.K. AU - Singh, M.P. AB - Commitment protocols are modularized specifications of interactions understood in terms of commitments. Purchase is a classic example of a protocol. Although a typical protocol would capture the essence of the interactions desired, in practice, it should be adapted depending on the circumstances or context and the agents' preferences based on that context. For example, when applying purchase in different contexts, it may help to allow sending reminders for payments or returning goods to obtain a refund. We contextualize a protocol by adapting it via different transformations.Our contributions are the following: (1) a protocol is transformed by composing its specification with a transformer specification; (2) contextualization is characterized operationally by relating the original and transformed protocols; and (3) contextualization is related to protocol compliance. C2 - 2006/// C3 - Proceedings of the International Conference on Autonomous Agents DA - 2006/// DO - 10.1145/1160633.1160884 VL - 2006 SP - 1345-1352 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-34247185859&partnerID=MN8TOARS ER - TY - CONF TI - Business process adaptations via protocols AU - Desai, N. AU - Chopra, A.K. AU - Singh, M.P. AB - Business process management in service-oriented computing (SOC) environments poses special challenges. In particular, SOC environments are dynamic, thereby requiring frequent changes in business processes. Current business process modeling approaches handle such changes in an ad hoc manner, and lack a principled means of determining what needs to be changed and where. This paper addresses process adaptability through a novel application of business protocols, especially of protocol composition, introduced in our previous work. Through a real business scenario of auto-insurance claim processing, this paper demonstrates how a wide range of adaptations can be handled naturally and systematically via protocol composition. The illustrated adaptations have been evaluated via a prototype C2 - 2006/// C3 - Proceedings - 2006 IEEE International Conference on Services Computing, SCC 2006 DA - 2006/// DO - 10.1109/SCC.2006.30 SP - 103-110 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-35148864924&partnerID=MN8TOARS ER - TY - JOUR TI - All-Integer Dual Simplex for Binate Cover Problems (Draft) AU - Stallmann, Matthias DA - 2006/// PY - 2006/// UR - https://people.engr.ncsu.edu/mfms/Publications/int-dual.pdf ER - TY - JOUR TI - Using Water Transfers to Manage Supply Risk AU - Characklis, G W AU - Kirsch, B R AU - Ramsey, J AU - Dillard, K E M AU - Kelley, C T T2 - Proceedings of Symposium on Safe Drinking Water: Where Science Meets Policy DA - 2006/// PY - 2006/// ER - TY - JOUR TI - Reduced order models for nonlinear least squares problems AU - Kelley, C T AU - Sorensen, D AU - Reese, J P AU - Winton, C DA - 2006/// PY - 2006/// ER - TY - CONF TI - Simulating Non-{D}arcy Flow through Porous Media using {S}undance AU - Reese, J P AU - Long, Kevin AU - Kelley, C T AU - Miller, C T AU - Gray, W G C2 - 2006/// C3 - Proceedings of Computational Methods in Water Resources XVI DA - 2006/// SP - Paper number 148, 8 pages ER - TY - JOUR TI - {SETraNS} Manual: Simulation of Electronic Transport in Nanoscale Structures AU - Lasater, M S AU - Recine, Greg AU - Kelley, C T AU - Woolard, D L AU - Zhao, P DA - 2006/// PY - 2006/// ER - TY - CONF TI - Simulating Nanoscale Devices AU - Lasater, M S AU - Kelley, C T AU - Salinger, A AU - Zhao, P AU - Woolard, D L A2 - Iwai, H A2 - Nishi, Y A2 - Shur, M S A2 - Wong, H C2 - 2006/// C3 - International Journal of High Speed Electronics and Systems DA - 2006/// VL - 16 SP - 677-690 PB - World Scientific ER - TY - JOUR TI - Parallel Parameter Study of the {Wigner-Poisson} Equations for {RTDs} AU - Lasater, M S AU - Kelley, C T AU - Salinger, A AU - Woolard, D L AU - Zhao, P T2 - Computers and Mathematics with Applications DA - 2006/// PY - 2006/// VL - 51 SP - 1677-1688 ER - TY - CONF TI - Nonlinear multilevel iterative methods for multiscale models of air/water flow in porous media AU - Kees, C E AU - Farthing, M W AU - Howington, S E AU - Jenkins, E W AU - Kelley, C T C2 - 2006/// C3 - Proceedings of Computational Methods in Water Resources XVI DA - 2006/// SP - Paper number 256, 8 pages ER - TY - JOUR TI - Model Reduction for Nonlinear Least Squares AU - Kelley, C T AU - Sorensen, D AU - Reese, J P AU - Winton, C DA - 2006/// PY - 2006/// ER - TY - JOUR TI - Special issue on accurate solution of eigenvalue problems AU - Ipsen, I.C.F. T2 - SIAM Journal on Matrix Analysis and Applications DA - 2006/// PY - 2006/// VL - 28 IS - 4 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-35348933724&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and techniques: Introduction AU - Ipsen, I.C.F. T2 - SIAM Review DA - 2006/// PY - 2006/// VL - 48 IS - 2 SP - 485-486 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33744920863&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - Related DatabasesWeb of Science You must be logged in with an active subscription to view this.Article DataHistoryPublished online: 17 February 2012Publication DataISSN (print): 0036-1445ISSN (online): 1095-7200Publisher: Society for Industrial and Applied MathematicsCODEN: siread DA - 2006/1// PY - 2006/1// DO - 10.1137/siread000048000003000485000001 VL - 48 IS - 3 SP - 485-485 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33751424677&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - The Problems and Techniques section in this issue contains three papers on very different topics: achieving reliability through optimization, improving the solution of systems of linear equations by preconditioning, and determining asymptotic expansion of integrals in Laplace form. Reliability is an important aspect in engineering design. One can make a system (such as a car) more reliable by introducing redundancy (e.g., carrying around a spare tire) or by making individual system components more reliable (e.g., using better material to manufacture car parts). In the first paper, James Falk, Nozer Singpurwalla, and Yefim Vladimirsky pursue the latter approach, opting to increase the reliability of individual components. This is called reliability allocation. Why not just adopt the simplest strategy and make all components of a system more reliable? This could be way too expensive. Consider, for instance, my Volkswagen GTI, a system with probably at least 3000 different components. Let's measure the reliability of the GTI by whether it drives or not. Replacing the plastic cup holder by one made from aluminum would cost a lot but would do nothing to increase the car's reliability. That's because the cup holder does not contribute to the drivability of the car (provided we disregard the driver who needs the cupholder for coffee to stay awake). However, replacing the plastic radiator by one made from aluminum costs only slightly more, but increases the reliability of the car significantly because the added cooling capacity prevents the engine from overheating when one wants to drive really fast. The question therefore is, which components of a system should we make more reliable, while keeping an eye on the cost? The authors propose to maximize a utility function that is aware of the interaction among components of the system, and trades off the cost of increasing reliability with greater probability of system functioning. In the second paper, Luis González presents a well-written and elegant analysis to justify the effectiveness of a particular approach for solving systems of linear equations. Systems of linear equations Ax = b whose coefficient matrix A has large dimension and is sparse (i.e., contains many zero elements) occur, for instance, whenever partial differential equations are discretized. Direct methods for solving Ax = b, such as Gaussian elimination, can be too expensive when they introduce too many nonzero elements during the course of the computation. In this case one may resort to iterative methods, which in successive iterations produce better and better approximations—or so one hopes. Unless one is lucky with one's matrix A, though, iterative methods can be slow and unreliable. Efficiency and reliability can be improved by preconditioning the system, i.e., transforming Ax = b into a preconditioned system (AN) y = b, where the matrix N is chosen such that the system (AN) y = b can be solved quickly, and the original solution x = Ny can be recovered easily. In this paper, the matrix N is chosen as an approximate inverse of A, so that the preconditioned matrix AN is close to the identity matrix I, and iterative methods applied to (AN) y = b converge fast. To ensure that recovery of the solution x = Ny is still easy, restrictions must be placed on N. The paper sets a very general context by assuming that N comes from some subspace S of matrices. Formally, the criterion is to choose N such that the residual $\|$AN – I$\|_{\fontsize{6pt}{6pt}\selectfont\textit{F}}$ is minimized, in the Frobenius norm, over all matrices from the subspace S. The idea for justifying the effectiveness of the preconditioner N is to cast the minimization problem in the form min$_{\fontsize{6pt}{6pt}\selectfont\textit{Q}}\|$Q – I$\|_{\fontsize{6pt}{6pt}\selectfont\textit{F}}$, where Q is a matrix from the subspace AS. The problem now amounts to analyzing orthogonal projections Q of the identity matrix I (hence the title of the paper). It turns out that if the smallest singular value of the preconditioned matrix AN is close to one and if also the smallest eigenvalue in magnitude is close to one, then everything works out: the residual $\|$AN – I$\|_{\fontsize{6pt}{6pt}\selectfont\textit{F}}$ is small, the matrix AN is well-conditioned, and its departure from normality is small. These are exactly the conditions that guarantee (in exact arithmetic) the effectiveness and reliability of the preconditioner N. To understand what's going on in the third paper, let's start with an example. The Gamma function can be represented as $$\hspace*{21pt}\hskip3pc \mbox{$\Gamma$($\lambda$ + 1) = $\displaystyle\int_{\mbox{\fontsize{6pt}{6pt}\selectfont 0}}^{\infty}$ u$^{\lambda}e^{\fontsize{6pt}{6pt}\selectfont\mbox{\fontsize{6pt}{6pt}\selectfont –}\textit{u}}$\textit{du},} $$ where $\lambda> $ 0. If we are interested in how $\Gamma$ depends on the positive parameter $\lambda$, we can determine the asymptotic expansion $$\hskip3pc\hspace*{21pt}\mbox{$\Gamma$($\lambda$ + 1) ~ \textit{e}$^{\mbox{\fontsize{6pt}{6pt}\selectfont–}\lambda} \lambda^{\mbox{\fontsize{6pt}{6pt}\selectfont$\lambda$ +\,1}}$ $\left(\frac{\displaystyle\mbox{2} \pi}{\mbox{\fontsize{9}{9pt}\selectfont$\lambda$}}\right)^{\mbox{\fontsize{6pt}{6pt}\selectfont 1/2}} \left[\mbox{1 + }{\mbox{1} \over \mbox{12}\mbox{\fontsize{9}{9pt}\selectfont$\lambda$}}\mbox{\,+\,}{\mbox{1}\over \mbox{288}\,\mbox{\fontsize{9}{9pt}\selectfont$\lambda$}^{\mbox{\fontsize{6pt}{6pt}\selectfont 2}}}\mbox{\,+\,}\cdots\right].$} $$ One way of obtaining such an asymptotic expansion is to change variables, u = $\lambda$(1 + x),set h(x) $\equiv$ x – log(1 + x), and write $$\hspace*{0pt}\hskip3pc\hspace*{26pt}\mbox{$\Gamma$($\lambda$ + 1) = \textit{e}$^{\mbox{\fontsize{6pt}{6pt}\selectfont–}\lambda} \lambda^{\mbox{\fontsize{6pt}{6pt}\selectfont$\lambda$ +\,1}} \displaystyle\int_{-1}^{\infty}$ \textit{e}$^{\mbox{\fontsize{6pt}{6pt}\selectfont–$\lambda$\textit{h}(\textit{x})}}$\textit{dx}.} $$ The integral is in Laplace form, i.e., it is of the form $$\hskip3pc\hspace*{23pt}\mbox{\textit{I}($\lambda$) = $\displaystyle\int_{\fontsize{6pt}{6pt}\selectfont\textit{a}}^{\fontsize{6pt}{6pt}\selectfont\textit{b}} \phi$(\textit{x})\textit{e}$^{\mbox{\fontsize{6pt}{6pt}\selectfont–$\lambda$\textit{h}(\textit{x})}}\textit{dx}$,} $$ where, in this special case, $\phi$(x) = 1, a = –1, and b = $\infty$. Here is the reason why Laplace's form is important, and why it was named after Laplace: Laplace observed that the major contributions to the integral I($\lambda$) come from those points where e$^{\fontsize{6pt}{6pt}\selectfont{-\textit{h}(\textit{x})}}$ attains its greatest values. He showed that if, among other things, h(x) has a minimum only at the left endpoint x = a, then the integral has the asymptotic expansion $$\hskip3pc \mbox{\textit{I}($\lambda$) ~ \textit{e}$^{\mbox{\fontsize{6pt}{6pt}\selectfont–$\lambda$\textit{h}(\textit{a})}}\> \displaystyle\sum_{\fontsize{6pt}{6pt}\selectfont\textit{s = 0}}^{\infty} \frac{\mbox{\textit{d}$_{\fontsize{6pt}{6pt}\selectfont\textit{s}}$}} {\lambda^{\mbox{\fontsize{6pt}{6pt}\selectfont($\alpha$ + \textit{s})$/\mu$}}}\qquad \mbox{as}~\lambda\rightarrow\infty$, } $$ where the numbers $\alpha$ and $\mu$ come from expansions of h(x) and $\phi$(x), respectively. However, symbolic computation of the coefficients d$_{\fontsize{6pt}{6pt}\selectfont\textit{s}}$ in asymptotic expansions of integrals in Laplace form I($\lambda$) has often been intractable. In his paper, John Wojdylo presents explicit expressions for the coefficients d$_{\fontsize{6pt}{6pt}\selectfont\textit{s}}$ that are more efficient and simpler than existing ones, and which should facilitate symbolic implementations. Laplace's method is one of several popular methods for determining asymptotic expansions of integrals (integration by parts is another). Asymptotic expansions can be more advantageous than numerical methods because they can reveal dependence on parameters that are physically significant, they can be differentiated or integrated exactly, and they can be more accurate. DA - 2006/1// PY - 2006/1// DO - 10.1137/siread000048000001000041000001 VL - 48 IS - 1 SP - 41-42 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33644586567&partnerID=MN8TOARS ER - TY - JOUR TI - Differential-Algebraic Equations AU - Campbell, Stephen AU - März, Roswitha AU - Rentrop, Peter AU - Petzold, Linda T2 - Oberwolfach Reports AB - The topic of Differential Algebraic Equations (DAEs) began to attract significant research interest in applied and numerical mathematics in the early 1980's. Today, a quarter of a century later, DAEs are an independent field of research, which is gaining in importance and becoming of increasing interest for both applications and mathematical theory.\\\ This Oberwolfach workshop brought together 48 experts in applied mathematics, among them, on the one hand, some who have already influenced and formed the developments of the field, and on the other hand, some very young researchers who have shown outstanding creativity and competence in connection with their PhD theses and thus raise great hopes for further advances.\\\ The 16 female and 32 male scientists came from 13 countries to meet and work together in the wonderful, unique Oberwolfach atmosphere, which stimulated a fruitful and pleasant collaboration.\\\ The schedule comprised a total of 34 presentations, 18 of which were arranged into 14 survey lectures (some of them with more than one speaker) offering a broader treatment of a particular subject. 16 shorter contributions supplemented the scientific programmme. The areas can be classified (of course with large overlap) into 4 groups: \begin{itemize} \item abstract differential algebraic systems, coupled systems, partial differential algebraic systems; \item analysis of (ordinary) differential algebraic equations and application of numerical methods to problems having new mathematical complexity; \item innovative and improved numerical integration methods to solve highly complex application problems; \item optimization with constraints described by DAEs and control problems concerning DAEs. \end{itemize} The broad range of these areas and the diversity of the participants stimulated fruitful discussions between the different branches and gave rise to new contacts and collaborations. A considerable gain in knowledgde and progress became obvious, which includes the formulation of open questions and challenges for the future.\\\ We are grateful to the Mathematisches Forschungsinstitut Oberwolfach for providing an inspiring setting for this workshop. DA - 2006/// PY - 2006/// DO - 10.4171/owr/2006/18 SP - 1077-1168 ER - TY - JOUR TI - Stochastic optimal control problems with a bounded memory AU - Chang, M.-H. AU - Pang, T. AU - Pemy, Moustapha T2 - Operations Research and Its Applications, Lecture Notes in Operations Research DA - 2006/// PY - 2006/// VL - 6 SP - 82–94 ER - TY - JOUR TI - Mathematical properties and analysis of Google’s PageRank AU - Ipsen, I.C.F. AU - Wills, R.S. T2 - Boletin de la Sociedad Espanola de Matematica Aplicada DA - 2006/// PY - 2006/// VL - 34 SP - 191–196 ER - TY - JOUR TI - Production scheduling in a knitted fabric dyeing and finishing process AU - Laoboonlur, P. AU - Hodgson, T. J. AU - Thoney, K. A. T2 - Journal of the Textile Institute AB - Abstract Developing detailed production schedules for dyeing and finishing operations is a very difficult task that has received relatively little attention in the literature. In this paper, a scheduling procedure is presented for a knitted fabric dyeing and finishing plant that is essentially a flexible job shop with sequence-dependent setups. An existing job shop scheduling algorithm is modified to take into account the complexities of the case plant. The resulting approach based on family scheduling is tested on problems generated with case plant characteristics. DA - 2006/8// PY - 2006/8// DO - 10.1533/joti.2006.0145 VL - 97 IS - 5 SP - 391-399 KW - dyeing KW - finishing KW - production KW - scheduling KW - setups ER - TY - JOUR TI - Algorithm to Systematically Reduce Human Errors in Healthcare AU - Seastrunk, Chad Stephen DA - 2006/// PY - 2006/// ER - TY - CONF TI - effective energy conservation in wireless sensor networks AU - Tezcan, N. AU - Wang, Wenye AB - In this paper, we present a two-tiered scheduling scheme that provides effective energy conservation in wireless sensor networks. The effectiveness of this scheme relies on dynamically updated two-tiered scheduling architecture. We aim to prolong network lifetime, while preserving the major requirements of wireless sensor networks: coverage and connectivity. In this approach, sensors are periodically scheduled to sleep in two phases using weighted greedy algorithms. First, we establish a coverage-tier by selecting a set of sensors that covers the sensing field in order to provide fully monitoring of entire field. Sensors that are not selected for the coverage-tier, are put into sleep immediately. Then, a second tier, called connectivity-tier, is formed on top of the coverage-tier to forward the data traffic to sink node. Thus sensors, essential to coverage-tier but not in connectivity-tier may periodically sleep and become active only for sending new sensing measurement and receiving query from the sink to preserve coverage. By this way, we may allow more nodes to sleep with different sleeping behaviors, i.e., continuous sleep or periodic sleep/active. Moreover, fair energy consumption among sensors is achieved by periodically rotating the coverage and connectivity tiers. Through extensive simulations in ns2, we demonstrate that the two-tier scheduling can reduce average energy consumption up to 40% while balancing the residual energy of sensors. C2 - 2006/// C3 - 2006 ieee international conference on communications, vols 1-12 DA - 2006/// DO - 10.1109/icc.2006.255235 SP - 3359–3364 ER - TY - CONF TI - Modeling and analysis of connectivity in mobile ad hoc networks with misbehaving nodes AU - Xing, F. AU - Wang, Wenye AB - Mobile ad hoc networks are vulnerable to malicious attacks and failures due to their unique features, such as node mobility and dynamic network topology. The design and evaluation of routing protocols and topology control require sound analysis on network connectivity and node behaviors. However, little work has been done on how node misbehaviors affect network connectivity. Modeling and analysis of node misbehavior involves many challenges such as multiple failures caused by selfishness, mobility, and potential Denial of Service attacks. Thus, we propose a novel model to characterize node misbehaviors based on a semi-Markov process. In particular, we analyze the impact of node misbehavior on network connectivity in a mobile ad hoc network stochastically. Numerical results based on analysis and simulations are provided to demonstrate the effectiveness of our approach and results. C2 - 2006/// C3 - 2006 ieee international conference on communications, vols 1-12 DA - 2006/// DO - 10.1109/icc.2006.254994 SP - 1879–1884 ER - TY - CONF TI - Metamodeling of Wi-Fi Performance AU - Hui, J. AU - Devetsikiotis, M. AB - The increasing popularity of Wireless Fidelity (Wi-Fi) networks at home, in public areas and in the enterprise motivates extensive modeling and analysis of their performance measures, such as network capacity, resource requirements and quality of service (QoS) capabilities. Some of the easier performance problems can be solved by analytical modeling methods, but most of the complicated ones, involving too many factors from multiple layers, can only be answered through validated simulation models. However, an explicit mathematic model is always the most effective way to represent the system behavior and the most convenient basis for performance optimization. Here, we first advocate the application of metamodeling techniques to performance studies of Wi-Fi networks, in order to find usable, if approximate, closed-form mathematical models. Subsequently, we formulate a general metamodeling framework for Wi-Fi networks. Our results in two relevant case studies, after applying this framework, support the validity of our metamodeling methodology: our capacity metamodel for 802.11 Distributed Coordination Function (DCF) is validated by a well-known analytical model and displays an interesting log-linear relationship between capacity and number of users; our voice over Wi-Fi admission capacity metamodel gives a much tighter bound than bounds existing in the literature and composes a more practical admission control scheme. Our work, therefore, points out a new direction for future performance studies of Wi-Fi networks. C2 - 2006/// C3 - 2006 ieee international conference on communications, vols 1-12 DA - 2006/// DO - 10.1109/icc.2006.254849 SP - 527-534 ER - TY - CONF TI - Dynamic wavelength sharing policies for absolute QoS in OBS networks AU - Yang, L. AU - Rouskas, G. N. AB - We consider the problem of providing absolute QoS guarantees to multiple classes of users of an OBS network in terms of the end-to-end burst loss. We employ Markov decision process (MDP) theory to develop wavelength sharing policies that maximize throughput while meeting the QoS guarantees. The randomized threshold policies we obtain are simple to implement and operate, and make effective use of statistical multiplexing. C2 - 2006/// C3 - Globecom 2006 - 2006 ieee global telecommunications conference DA - 2006/// DO - 10.1109/glocom.2006.386 ER - TY - CONF TI - Challenges in service-oriented networking AU - Callaway, R. D. AU - Rodriguez, A. AU - Devetsikiotis, M. AU - Cuomo, G. AB - We believe that application-aware networks will be a core component in the development and deployment of emerging network services. However, previous attempts at enabling application-awareness in the network have failed due to issues with security, resource allocation, and cost of deployment. The emergence of the Extensible Markup Language (XML), an open standard that enables data interoperability, along with advances in hardware, software, and networking technologies, serves as the catalyst for the development of service-oriented networking (SON). SON enables network components to become application-aware, so that they are able to understand data encoded in XML and act upon that data intelligently to make routing decisions, enforce QoS or security policies, or transform the data into an alternate representation. This paper describes the motivation behind service-oriented networking, the potential benefits of introducing application-aware network devices into service-oriented architectures, and discusses research challenges in the development of SON-enabled network appliances. C2 - 2006/// C3 - Globecom 2006 - 2006 ieee global telecommunications conference DA - 2006/// DO - 10.1109/glocom.2006.419 ER - TY - CONF TI - A novel semi-Markov smooth mobility model for mobile ad hoc networks. AU - Zhao, M. AU - Wang, Wenye AB - Existing random mobility models have their limitations such as speed decay and sharp turn which have been demonstrated by the previous studies. More importantly, mobility models need to mimic the movements that abide by the physical law for accurate analysis and simulations of mobile networks. Therefore, in this paper, we propose a novel mobility model, semi-Markov smooth (SMS) model. Each SMS movement includes three consecutive phases: speed up phase, middle smooth phase, and slow down phase. Thus, the entire motion in the SMS model is smooth and consistent with the moving behaviors in real environment. Through steady state analysis, we demonstrate that SMS model has no average speed decay problem and always maintains a uniform spatial node distribution. The analytical results are validated by extensive simulation experiments. In addition, we compare the simulation results on link lifetime and percentage of node degree with random waypoint model, Gauss-Markov model and the proposed SMS model. C2 - 2006/// C3 - Globecom 2006 - 2006 ieee global telecommunications conference DA - 2006/// DO - 10.1109/glocom.2006.940 ER - TY - CONF TI - The relationship between high school mathematics and career choices among high achieving young women AU - Berenson, S. B. AU - Michael, J. J. AU - Vouk, M. C2 - 2006/// C3 - Pme 30: proceedings of the 30th conference of the international group for the psychology of mathematics education, vol 1, DA - 2006/// SP - 220-220 ER - TY - CONF TI - Supply Chain Multi-Objective Simulation Optimization AU - Joines, J.A. AU - Thoney, K. AU - Kay, M.G. C2 - 2006/// C3 - Proceedings of the 4th International Industrial Simulation Conference DA - 2006/// VL - 125-132 SP - 125-132 PB - Ostend: EUROSIS-ETI SN - 9789077381267 ER - TY - CHAP TI - Probes as path seekers - A new paradigm AU - Demers, A. AU - List, G. F. AU - Wallace, W. A. AU - Lee, E. E. AU - Wojtowicz, J. M. T2 - Intelligent transportation systems and vehicle-highway automation 2006 AB - In a recent field experiment, a fleet of Global Positioning System—equipped vehicles shared real-time data about network travel times over a wireless network and had their path choices automatically updated accordingly. This paper describes the behavior of these 200 vehicles during the 3-month experiment and illustrates the kind of information that can be derived from the data archive that the vehicles created. Much can be learned about real-time traffic-responsive path choice, travel times, compliance, and more. Planners, designers, and system operators can learn much about the way a system behaves and can sharpen their ability to create systems that work effectively and efficiently under all ranges of use. True path seeking by probe-equipped vehicles will arise when such vehicles become a common part of the vehicle fleet. PY - 2006/// DO - 10.3141/1944-14 SP - 107-114 PB - Washington: Transportation Research Board Natl Research Council ER - TY - JOUR TI - Posterior consistency of Gaussian process prior for nonparametric binary regression AU - Ghosal, Subhashis AU - Roy, Anindya T2 - ANNALS OF STATISTICS AB - Consider binary observations whose response probability is an unknown smooth function of a set of covariates. Suppose that a prior on the response probability function is induced by a Gaussian process mapped to the unit interval through a link function. In this paper we study consistency of the resulting posterior distribution. If the covariance kernel has derivatives up to a desired order and the bandwidth parameter of the kernel is allowed to take arbitrarily small values, we show that the posterior distribution is consistent in the L1-distance. As an auxiliary result to our proofs, we show that, under certain conditions, a Gaussian process assigns positive probabilities to the uniform neighborhoods of a continuous function. This result may be of independent interest in the literature for small ball probabilities of Gaussian processes. DA - 2006/10// PY - 2006/10// DO - 10.1214/009053606000000795 VL - 34 IS - 5 SP - 2413-2429 SN - 0090-5364 KW - binary regression KW - Gaussian process KW - Karhunen-Loeve expansion KW - maximal inequality KW - posterior consistency KW - reproducing kernel Hilbert space ER - TY - JOUR TI - Creating supply chain relational capital: The impact of formal and informal socialization processes AU - Cousins, Paul D. AU - Handfield, Robert B. AU - Lawson, Benn AU - Petersen, Kenneth J. T2 - JOURNAL OF OPERATIONS MANAGEMENT AB - Abstract Establishing closer social ties between buying and supplying organizations is increasingly cited as a critical differentiator of high and low performers in global supply chains. While the creation of relational capital within an organization is a relatively well identified concept in organizational research, comparatively little research exists on the inter‐organizational socialization processes that create relational value in supply chains. In our research, we extend theoretical models of group social conduits into this context, and develop a model that posits the impact of formal and informal socialization processes on the creation of relational capital between buyers and suppliers. Results from our study of 111 manufacturing organizations in the United Kingdom suggest that informal socialization processes are important in the creation of relational capital, which in turn can lead to improved supplier relationship outcomes. Formal bridging socialization conduits appear to play a lesser role in deriving these benefits. DA - 2006/12// PY - 2006/12// DO - 10.1016/j.jom.2005.08.007 VL - 24 IS - 6 SP - 851-863 SN - 1873-1317 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33751310092&partnerID=MN8TOARS KW - supply management KW - socialization KW - relational capital KW - structural equation modelling KW - supply chain management ER - TY - JOUR TI - Capacity allocation with traditional and Internet channels AU - Dai, Yue AU - Chao, Xiuli AU - Fang, Shu-Cherng AU - Nuttle, Henry L. W. T2 - NAVAL RESEARCH LOGISTICS AB - Abstract In this paper we study a capacity allocation problem for two firms, each of which has a local store and an online store. Customers may shift among the stores upon encountering a stockout. One question facing each firm is how to allocate its finite capacity (i.e., inventory) between its local and online stores. One firm's allocation affects the decision of the rival, thereby creating a strategic interaction. We consider two scenarios of a single‐product single‐period model and derive corresponding existence and stability conditions for a Nash equilibrium. We then conduct sensitivity analysis of the equilibrium solution with respect to price and cost parameters. We also prove the existence of a Nash equilibrium for a generalized model in which each firm has multiple local stores and a single online store. Finally, we extend the results to a multi‐period model in which each firm decides its total capacity and allocates this capacity between its local and online stores. A myopic solution is derived and shown to be a Nash equilibrium solution of a corresponding “sequential game.” © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 DA - 2006/12// PY - 2006/12// DO - 10.1002/nav.20168 VL - 53 IS - 8 SP - 772-787 SN - 0894-069X KW - capacity allocation KW - game theory KW - nash equilibrium KW - sequential game ER - TY - JOUR TI - Dissecting the routing architecture of self-organizing networks AU - Amorim, Marcelo AU - Benbadis, Farid AU - Fdida, Serge AU - Sichitiu, Mihail L. AU - Viniotis, Yannis T2 - IEEE WIRELESS COMMUNICATIONS AB - The proper operation of self-organizing networks (SONs) relies on the autonomous behavior of their individual nodes. Routing in such networks has been a challenging task since their conception, due to their nontraditional characteristics and design requirements. Although a large amount of routing architectures and protocols for SONs has been proposed, very little work has been done on the fundamental characteristics that make a routing strategy efficient for a particular network and/or design requirement. Contrary to traditional techniques where the routing architecture is structured as a single unit, we suggest in this article that routing be thought of as a combination of four main architectural components, namely, addressing, dissemination, discovery, and forwarding. This logical decomposition offers significant advantages from both the analysis and the design perspectives. We conclude from our observations that routing architectures should be scenario-driven, in the sense that the configuration parameters are not necessarily universally good for all application scenarios DA - 2006/12// PY - 2006/12// DO - 10.1109/MWC.2006.275204 VL - 13 IS - 6 SP - 98-104 SN - 1558-0687 ER - TY - JOUR TI - Spatially distributed stochastic systems: Equation-free and equation-assisted preconditioned computations AU - Qiao, Liang AU - Erban, Radek AU - Kelley, C. T. AU - Kevrekidis, Ioannis G. T2 - JOURNAL OF CHEMICAL PHYSICS AB - Spatially distributed problems are often approximately modeled in terms of partial differential equations (PDEs) for appropriate coarse-grained quantities (e.g., concentrations). The derivation of accurate such PDEs starting from finer scale, atomistic models, and using suitable averaging is often a challenging task; approximate PDEs are typically obtained through mathematical closure procedures (e.g., mean field approximations). In this paper, we show how such approximate macroscopic PDEs can be exploited in constructing preconditioners to accelerate stochastic computations for spatially distributed particle-based process models. We illustrate how such preconditioning can improve the convergence of equation-free coarse-grained methods based on coarse timesteppers. Our model problem is a stochastic reaction-diffusion model capable of exhibiting Turing instabilities. DA - 2006/11/28/ PY - 2006/11/28/ DO - 10.1063/1.2372492 VL - 125 IS - 20 SP - SN - 1089-7690 ER - TY - JOUR TI - Production scheduling in a knitted fabric dyeing and finishing process AU - Laoboonlur, P. AU - Hodgson, Thom AU - Thoney, K. A. T2 - Journal of the Textile Institute DA - 2006/// PY - 2006/// DO - 10.1533/joti.2005.0145 VL - 97 IS - 5 SP - 391–399 ER - TY - JOUR TI - Probabilistic robust linear parameter-varying control of an F-16 aircraft AU - Lu, Bei AU - Wu, Fen T2 - JOURNAL OF GUIDANCE CONTROL AND DYNAMICS AB - O PERATIONAL capability at high angles of attack, especially near and at post stall regimes, is critical for next generation fighter aircrafts and uninhabited aerial vehicles [1]. However, significantly large levels of modeling uncertainty are inevitably encountered inflight control design for those regimes. The sources of uncertainty include variations in mass, inertia, and center of gravity positions, uncertainty in the aerodynamic data, etc. [2]. The maneuverability at high angles of attack poses a challenging control problem that requires guaranteeing both robust stability and robust performance in the presence of large parameter variations. Traditional robust control techniques, like H1 and -synthesis, have been proven to be capable of producing robust uncertaintytolerant controllers for next generation aircrafts [2,3]. However, those techniques focus on deterministic worst-case robust analysis and synthesis, which often lead to overly conservative stability bound estimate and high control effort. Moreover, a large number of conventional deterministic problems in robustness analysis and synthesis are shown to be NP-hard. To reduce conservatism and computational complexity, one approach is to shift the meaning of robustness from its usual deterministic sense to a probabilistic one [4]. In contrast to traditional robust control techniques, only a probabilistic solution is given, and a certain risk-level should be accepted. However, such a system may be viewed as being practically robust from an engineering point of view. Algorithms derived in the probabilistic context are based on uncertainty randomization and usually called randomized algorithms, which may be divided into two families: methods based on statistical learning theory [5], and sequential methods based on subgradient iterations [6–8] or ellipsoid iterations [9,10]. The former can deal with nonconvex synthesis problems; however, it resorts to randomized search over the controller parameters to find a candidate solution. On the other hand, the sequential methods are formulated based on convex problems, thus avoiding the controller randomization issue [4]. The probabilistic robust control approach is still in the stage of algorithm development and improvement, and has not been explored in depth for flight control. The number of implementation of probabilistic techniques is therefore rather restricted. In the late 90s, Marrison and Stengel designed a linear quadratic regulator to control the nonlinear longitudinal dynamics of a hypersonic aircraft [11]. Recently, Wang and Stengel designed a robust flight control system for the high-incidence research model problem by combining stochastic robustness with nonlinear dynamic inversion [12]. Their work was based on statistical learning theory, and controllers were searched by using generic algorithms to minimize stochastic robustness cost functions. In our earlier paper, we applied an ellipsoid algorithm to design anH1 controller for a linearized F-16 longitudinal model [13]. Good stability and performance robustness have been achieved at the chosen flight condition. The motivation for this research is twofold. First, the probabilistic control design method for linear time-invariant plants in [13] is generalized to linear parameter-varying (LPV) systems. This generalization is very important because of the relevance of LPV systems to nonlinear systems. TheLPVcontrol synthesis condition is known to be formulated as a convex problemwith a set of parameterdependent linear matrix inequalities (LMIs) [14–16]. Second, the current state of the art does not allow accurate aerodynamicmodeling in the high angle of attack region. Because of its random nature, uncertainty in the aerodynamic data can be characterized using a statistical model, which can be handled effectively by the promising probabilistic robust control approach. Note that the study in this note focuses on the robustness issue with respect to the aerodynamic uncertainty at high angles of attack, and the results would be easily generalized to other parametric uncertainties, such as variations in mass and inertial properties. Because of the convex formulation of LPV control synthesis, the sequential method is more suitable for dealing with uncertainties and designing probabilistic robust LPV controllers. An ellipsoid algorithm with a stopping rule proposed by Oishi [10] is used to determine feasible solutions to LMI synthesis conditions. The paper is organized as follows. In Sec. II, the ellipsoid algorithm is presented, which either gives a probabilistic solution with high confidence or detects that there is no deterministic solution in an approximated sense. Section III first provides a brief overview of robust control problem of an uncertain LPV system, and then discusses the computational issues when the algorithm is applied to the robust LPV control problem. In Sec. IV, a robust LPV controller is designed for an F-16 aircraft with large aerodynamic uncertainty, and the robust performance is tested through nonlinear simulations. Finally, the paper concludes with a summary in Sec. V. DA - 2006/// PY - 2006/// DO - 10.2514/1.22495 VL - 29 IS - 6 SP - 1454-1460 SN - 1533-3884 ER - TY - JOUR TI - A structured erythropoiesis model with nonlinear cell maturation velocity and hormone decay rate AU - Ackleh, Azmy S. AU - Deng, Keng AU - Ito, Kazufumi AU - Thibodeaux, Jeremy T2 - MATHEMATICAL BIOSCIENCES AB - We develop a quasilinear structured model that describes the regulation of erythropoiesis, the process in which red blood cells are developed. In our model, the maturation velocity of precursor cells is assumed to be a function of the erythropoietin hormone, and the decay rate of this hormone is assumed to be a function of the number of precursor cells, unlike other models which assume these parameters to be constants. Existence-uniqueness results are established and convergence of a finite difference approximation to the unique solution of the model is obtained. The finite difference scheme is then used to investigate the effects of these nonlinear parameters on the model dynamics. Our results show that a velocity of precursor cells maturation rate which is an increasing function of the hormone level and a decay rate of the hormone which is an increasing function of the number of precursor cells have a stabilizing effect on the dynamics of the model. While assuming that one parameter is a function and letting the other be a constant stabilizes the oscillations in the mature cells level, the effect is more significant when both parameters are taken to be functions. A study of robustness with respect to the forms of these functions and parameter sensitivity is also carried out. DA - 2006/11// PY - 2006/11// DO - 10.1016/j.mbs.2006.08.004 VL - 204 IS - 1 SP - 21-48 SN - 1879-3134 KW - erythropoiesis KW - structured model KW - finite difference approximation KW - existence-uniqueness KW - behavior of solutions ER - TY - JOUR TI - A semantics based approach to privacy languages AU - Li, N. AU - Yu, T. AU - Anton, A. T2 - Computer Systems Science and Engineering DA - 2006/// PY - 2006/// VL - 21 IS - 5 SP - 339-352 ER - TY - JOUR TI - Special issue on accurate solution of eigenvalue problems AU - Ipsen, Ilse C. F. T2 - SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS AB - The occasion for this special issue is the Fifth International Workshop on Accurate Solution of Eigenvalue Problems, which took place in Hagen, Germany from June 29 to July 1, 2004. This issue provides an outlet for papers from the workshop and recognizes advances in the numerical solution of eigenvalue and related problems. Refined perturbation theory, careful error analyses, and creative algorithms have led to numerical methods that are more accurate and at the same time more efficient. The fourteen papers in this issue are concerned with ordinary eigenvalue problems, eigenvalue problems for matrix polynomials, and singular value decompositions. A common thread is the judicious exploitation of structure in the matrices. Thanks go to Henk van der Vorst, Mitch Chernoff, and the SIAM staff for providing a home for the special issue and to the guest editors Jesse Barlow, Beresford Parlett, and Kresimir Veselić, who saw to the careful and timely review of the papers. DA - 2006/// PY - 2006/// DO - 10.1137/sjmael0000280000040000ix000001 VL - 28 IS - 4 SP - IX-IX SN - 0895-4798 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-35348933724&partnerID=MN8TOARS ER - TY - BOOK TI - Google's PageRank and beyond: The science of search engine rankings AU - Langville, A. N. AU - Meyer, C. D. AB - Why doesn't your home page appear on the first page of search results, even when you query your own name? How do other web pages always appear at the top? What creates these powerful rankings? And how? The first book ever about the science of web page rankings, Google's PageRank and Beyond supplies the answers to these and other questions and more. The book serves two very different audiences: the curious science reader and the technical computational reader. The chapters build in mathematical sophistication, so that the first five are accessible to the general academic reader. While other chapters are much more mathematical in nature, each one contains something for both audiences. For example, the authors include entertaining asides such as how search engines make money and how the Great Firewall of China influences research. The book includes an extensive background chapter designed to help readers learn more about the mathematics of search engines, and it contains several MATLAB codes and links to sample web data sets. The philosophy throughout is to encourage readers to experiment with the ideas and algorithms in the text. Any business seriously interested in improving its rankings in the major search engines can benefit from the clear examples, sample code, and list of resources provided. Many illustrative examples and entertaining asides MATLAB code Accessible and informal style Complete and self-contained section for mathematics review CN - TK5101.884 .L36 2006 DA - 2006/// PY - 2006/// DO - 10.1515/9781400830329 PB - Princeton, NJ: Princeton University Press SN - 0691122024 ER - TY - JOUR TI - Updating Markov chains with an eye on Google's PageRank AU - Langville, AN AU - Meyer, CD T2 - SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS AB - An iterative algorithm based on aggregation/disaggregation principles is presented for updating the stationary distribution of a finite homogeneous irreducible Markov chain. The focus is on large-scale problems of the kind that are characterized by Google's PageRank application, but the algorithm is shown to work well in general contexts. The algorithm is flexible in that it allows for changes to the transition probabilities as well as for the creation or deletion of states. In addition to establishing the rate of convergence, it is proven that the algorithm is globally convergent. Results of numerical experiments are presented. DA - 2006/// PY - 2006/// DO - 10.1137/040619028 VL - 27 IS - 4 SP - 968-987 SN - 1095-7162 KW - Markov chains KW - updating KW - stationary vector KW - PageRank KW - stochastic complementation KW - aggregation/disaggregation KW - Google ER - TY - JOUR TI - Reduced order control based on approximate inertial manifolds AU - Ito, Kazufumi AU - Kunisch, Karl T2 - LINEAR ALGEBRA AND ITS APPLICATIONS AB - A reduced-order method based on approximate inertial manifolds is applied to optimal control problems in infinite-dimensional state spaces. A detailed analysis of the method is given for the linear quadratic regulator problem. The method can also be applied to higher-order control systems with an appropriate decomposition of the state space in terms of slow and fast exponential decay. DA - 2006/6/1/ PY - 2006/6/1/ DO - 10.1016/j.laa.2004.10.019 VL - 415 IS - 2-3 SP - 531-541 SN - 1873-1856 KW - reduced order method KW - approximate inertial manifold KW - LQR-problern KW - decomposition of state space KW - infinite-dimensional system ER - TY - JOUR TI - Receding horizon control with incomplete observations AU - Ito, K AU - Kunisch, K T2 - SIAM JOURNAL ON CONTROL AND OPTIMIZATION AB - To overcome the difficulties related to the computational requirements for solving the optimality systems for optimal control problems on long time horizons, receding horizon techniques provide an important alternative. Rather than finding the optimal solution, a suboptimal control is obtained which achieves the design objective with significantly less computational effort. Moreover, the obtained control can be interpreted as a state feedback control. In this work we continue our analysis of receding horizon strategies, considering the situation when only partial state observations are available. The receding horizon strategy is combined with a state estimator framework. A linearquadratic Gaussian design based on a linearization procedure is proposed and its asymptotic performance is analyzed for systems with nonlinear dynamics. Numerical examples validate the proposed methodology. DA - 2006/// PY - 2006/// DO - 10.1137/S0363012903437988 VL - 45 IS - 1 SP - 207-225 SN - 1095-7138 KW - receding horizon control KW - incomplete observations KW - dynamic compensator ER - TY - JOUR TI - Predicting Shine-Dalgarno sequence locations exposes genome annotation errors AU - Starmer, J. AU - Stomp, A. AU - Vouk, M. AU - Bitzer, D. T2 - PLOS COMPUTATIONAL BIOLOGY AB - In prokaryotes, Shine-Dalgarno (SD) sequences, nucleotides upstream from start codons on messenger RNAs (mRNAs) that are complementary to ribosomal RNA (rRNA), facilitate the initiation of protein synthesis. The location of SD sequences relative to start codons and the stability of the hybridization between the mRNA and the rRNA correlate with the rate of synthesis. Thus, accurate characterization of SD sequences enhances our understanding of how an organism's transcriptome relates to its cellular proteome. We implemented the Individual Nearest Neighbor Hydrogen Bond model for oligo-oligo hybridization and created a new metric, relative spacing (RS), to identify both the location and the hybridization potential of SD sequences by simulating the binding between mRNAs and single-stranded 16S rRNA 3' tails. In 18 prokaryote genomes, we identified 2,420 genes out of 58,550 where the strongest binding in the translation initiation region included the start codon, deviating from the expected location for the SD sequence of five to ten bases upstream. We designated these as RS+1 genes. Additional analysis uncovered an unusual bias of the start codon in that the majority of the RS+1 genes used GUG, not AUG. Furthermore, of the 624 RS+1 genes whose SD sequence was associated with a free energy release of less than -8.4 kcal/mol (strong RS+1 genes), 384 were within 12 nucleotides upstream of in-frame initiation codons. The most likely explanation for the unexpected location of the SD sequence for these 384 genes is mis-annotation of the start codon. In this way, the new RS metric provides an improved method for gene sequence annotation. The remaining strong RS+1 genes appear to have their SD sequences in an unexpected location that includes the start codon. Thus, our RS metric provides a new way to explore the role of rRNA-mRNA nucleotide hybridization in translation initiation. DA - 2006/5// PY - 2006/5// DO - 10.1371/journal.pcbi.0020057 VL - 2 IS - 5 SP - 454-466 SN - 1553-7358 ER - TY - JOUR TI - Model development for atomic force microscope stage mechanisms AU - Smith, Ralph C. AU - Hatch, Andrew G. AU - De, Tathagata AU - Salapaka, Murti V. AU - Del Rosario, Ricardo C. H. AU - Raye, Julie K. T2 - SIAM JOURNAL ON APPLIED MATHEMATICS AB - In this paper, we develop nonlinear constitutive equations and resulting system models quantifying the nonlinear and hysteretic field‐displacement relations inherent to lead zirconate titanate (PZT) devices employed in atomic force microscope stage mechanisms. We focus specifically on PZT rods utilizing $d_{33}$ motion and PZT shells driven in $d_{31}$ regimes, but the modeling framework is sufficiently general to accommodate a variety of drive geometries. In the first step of the model development, lattice‐level energy relations are combined with stochastic homogenization techniques to construct nonlinear constitutive relations which accommodate the hysteresis inherent to ferroelectric compounds. Second, these constitutive relations are employed in classical rod and shell relations to construct system models appropriate for presently employed nanopositioner designs. The capability of the models for quantifying the frequency‐dependent hysteresis inherent to the PZT stages is illustrated through comparison with experimental data. DA - 2006/// PY - 2006/// DO - 10.1137/05063307X VL - 66 IS - 6 SP - 1998-2026 SN - 1095-712X KW - atomic force microscope KW - hysteresis model KW - dynamics ER - TY - JOUR TI - Locally invertible multivariate polynomial matrices AU - Lobo, R. G. AU - Bitzer, D. L. AU - Vouk, M. A. T2 - Lecture Notes in Computer Science DA - 2006/// PY - 2006/// IS - 3969 SP - 427-441 ER - TY - JOUR TI - Conjunctive use of models to design cost-effective ozone control strategies AU - Fu, Joshua S. AU - Brill, E. Downey, III AU - Ranjithan, S. Ranji T2 - JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION AB - Abstract The management of tropospheric ozone (O3) is particularly difficult. The formulation of emission control strategies requires considerable information including: (1) emission inventories, (2) available control technologies, (3) meteorological data for critical design episodes, and (4) computer models that simulate atmospheric transport and chemistry. The simultaneous consideration of this information during control strategy design can be exceedingly difficult for a decision-maker. Traditional management approaches do not explicitly address cost minimization. This study presents a new approach for designing air quality management strategies; a simple air quality model is used conjunctively with a complex air quality model to obtain low-cost management strategies. A simple air quality model is used to identify potentially good solutions, and two heuristic methods are used to identify cost-effective control strategies using only a small number of simple air quality model simulations. Subsequently, the resulting strategies are verified and refined using a complex air quality model. The use of this approach may greatly reduce the number of complex air quality model runs that are required. An important component of this heuristic design framework is the use of the simple air quality model as a screening and exploratory tool. To achieve similar results with the simple and complex air quality models, it may be necessary to “tweak” or calibrate the simple model. A genetic algorithm-based optimization procedure is used to automate this tweaking process. These methods are demonstrated to be computationally practical using two realistic case studies, which are based on data from a metropolitan region in the United States. DA - 2006/6// PY - 2006/6// DO - 10.1080/10473289.2006.10464492 VL - 56 IS - 6 SP - 800-809 SN - 2162-2906 ER - TY - CHAP TI - Characterization of the burst aggregation process in optical burst switching AU - Mountrouidou, X. AU - Perros, H. G. T2 - Networking 2006. Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications Systems: 5th International IFIP-TC6 Networking Conference, Coimbra, Portugal, May 15-19, 2006. Proceedings (Lecture notes in computer science; 3976) AB - We describe an analytic approach for the calculation of the departure process from a burst ggregation algorithm that uses both a timer and maximum/minimum burst size. The arrival process of packets is assumed to be Poisson or bursty modelled by an Interrupted Poisson Process (IPP). The analytic results are approximate and validation against simulation data showed that they have good accuracy. PY - 2006/// DO - 10.1007/11753810_63 VL - 3976 SP - 752-764 PB - Berlin; New York: Springer ER - TY - JOUR TI - Answering queries using materialized views with minimum size AU - Chirkova, Rada AU - Li, Chen AU - Li, Jia T2 - VLDB JOURNAL AB - In this paper, we study the following problem. Given a database and a set of queries, we want to find a set of views that can compute the answers to the queries, such that the amount of space, in bytes, required to store the viewset is minimum on the given database. (We also handle problem instances where the input has a set of database instances, as described by an oracle that returns the sizes of view relations for given view definitions.) This problem is important for applications such as distributed databases, data warehousing, and data integration. We explore the decidability and complexity of the problem for workloads of conjunctive queries. We show that results differ significantly depending on whether the workload queries have self-joins. Further, for queries without self-joins we describe a very compact search space of views, which contains all views in at least one optimal viewset. We present techniques for finding a minimum-size viewset for a single query without self-joins by using the shape of the query and its constraints, and validate the approach by extensive experiments. DA - 2006/9// PY - 2006/9// DO - 10.1007/s00778-005-0162-8 VL - 15 IS - 3 SP - 191-210 SN - 0949-877X KW - views KW - data warehouses KW - minimum-size viewsets KW - distributed systems ER - TY - JOUR TI - Additive scaling and the DIRECT algorithm AU - Finkel, D. E. AU - Kelley, C. T. T2 - JOURNAL OF GLOBAL OPTIMIZATION DA - 2006/12// PY - 2006/12// DO - 10.1007/s10898-006-9029-9 VL - 36 IS - 4 SP - 597-608 SN - 0925-5001 KW - DIRECT KW - global optimization KW - additive scaling ER - TY - JOUR TI - A homogenized energy model for the direct magnetomechanical effect AU - Smith, Ralph C. AU - Dapino, Marcelo J. T2 - IEEE TRANSACTIONS ON MAGNETICS AB - This paper focuses on the development of a homogenized energy model which quantifies certain facets of the direct magnetomechanical effect. In the first step of the development, Gibbs energy analysis at the lattice level is combined with Boltzmann principles to quantify the local average magnetization as a function of input fields and stresses. A macroscopic magnetization model, which incorporates the effects of polycrystallinity, material nonhomogeneities, stress-dependent interaction fields, and stress-dependent coercive behavior, is constructed through stochastic homogenization techniques based on the tenet that local coercive and interaction fields are manifestations of underlying distributions rather than constants. The resulting framework incorporates previous ferromagnetic hysteresis theory as a special case in the absence of applied stresses. Attributes of the framework are illustrated through comparison with previously published steel and iron data DA - 2006/8// PY - 2006/8// DO - 10.1109/TMAG.2006.875705 VL - 42 IS - 8 SP - 1944-1957 SN - 0018-9464 KW - ferromagnetic materials KW - magnetic hysteresis KW - magnetornechanical effects KW - magnetostrictive devices KW - modeling KW - nonlinear magnetics ER - TY - JOUR TI - A cost-minimization algorithm for fast location tracking in mobile wireless networks AU - Wang, Wenye AU - Xue, Guoliang T2 - COMPUTER NETWORKS AB - Location tracking is one of the most important issues in providing real-time applications over wireless networks due to its effect to quality of service (QoS), such as end-to-end delay, bandwidth utilization, and connection dropping probability. In this paper, we study cost minimization for locating mobile users under delay constraints in mobile wireless networks. Specifically, a new location tracking algorithm is developed to determine the position of mobile terminals under delay constraints, while minimizing the average locating cost based on a unimodal property. We demonstrate that the new algorithm not only results in minimum locating cost, but also has a lower computational complexity compared to existing algorithms. Furthermore, detailed searching procedures are discussed under both deterministic and statistic delay bounds. Numerical results for a variety of location probability distributions show that our algorithm compares favorably with existing algorithms. DA - 2006/10/18/ PY - 2006/10/18/ DO - 10.1016/j.comnet.2005.09.035 VL - 50 IS - 15 SP - 2713-2726 SN - 1872-7069 KW - wireless networks KW - location tracking KW - partition KW - optimization ER - TY - JOUR TI - Twins: A dual addressing space representation for self-organizing networks AU - Carneiro Viana, Aline AU - Amorim, Marcelo AU - Viniotis, Yannis AU - Fdida, Serge AU - Rezende, Jose T2 - IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS AB - As the size of mobile self-organizing networks increases, the efficiency of location services must increase as well so that addressing/routing scalability does not become an issue. In this paper, we propose a novel architecture, called Twins, tailored for self-organizing networks. Twins architecture involves addressing and locating nodes in large networks, forwarding packets between them, and managing in the presence of mobility/topology changes. Twins defines a logical multidimensional space for addressing and forwarding, while location service and management operations make use of a one-dimensional space. To improve scalability and performance, forwarding is hop-by-hop with greedy next-hop choice and the location service uses a rendezvous paradigm to distribute information among nodes. In this paper, we describe the Twins architecture and present a performance evaluation to assess scalability, fairness in the overhead distribution among nodes, and routing robustness. DA - 2006/12// PY - 2006/12// DO - 10.1109/TPDS.2006.179 VL - 17 IS - 12 SP - 1468-1481 SN - 1558-2183 KW - distributed networks KW - network topology KW - wireless communication KW - protocol architecture KW - routing protocols ER - TY - BOOK TI - The immersed interface method: Numerical solutions of PDEs involving interfaces and irregular domains AU - Li, Zhilin AU - Ito, K. CN - QA374 .L42 2006 DA - 2006/// PY - 2006/// DO - 10.1137/1.9780898717464 PB - Philadelphia: SIAM, Society for Industrial and Applied Mathematics SN - 0898716098 ER - TY - JOUR TI - The Picard iteration and its application AU - Chen, X AU - Hartwig, RE T2 - LINEAR & MULTILINEAR ALGEBRA AB - The convergence behavior of the Picard iteration Xk+1=AXk+B and the weighted case Yk=Xk/bk is investigated. It is shown that the convergence of both these iterations is related to the so-called effective spectrum of A with respect to some matrix. As an application of our convergence results we discuss the convergence behavior of a sequence of scaled triangular matrices {DNTN }. DA - 2006/9// PY - 2006/9// DO - 10.1080/03081080500209703 VL - 54 IS - 5 SP - 329-341 SN - 0308-1087 KW - Picard iteration KW - Schur complement KW - path condition ER - TY - JOUR TI - Supply management's evolution: key skill sets for the supply manager of the future AU - Giunipero, Larry AU - Handfield, Robert B. AU - Eltantawy, Reham T2 - INTERNATIONAL JOURNAL OF OPERATIONS & PRODUCTION MANAGEMENT AB - Purpose In the last decade there have been dramatic impacts on, and changes within, the field of purchasing/supply management. Given supply management's new strategic role, this research seeks to examine the key skills and knowledge necessary for firms to improve in order to maximize the purchasing function's contribution to the organization. The research also aims to identifies the major shifts in supply management that have occurred in the last decade. Design/methodology/approach A qualitative study was conducted with a series of focus group meetings with 54 executives across the USA in order to construct theoretical relationships with which to develop a grounded theory of supply management skills evolution in a changing business environment. Findings The implications from this research indicate that supply management professionals will assume a more strategic role in the future. The data indicate that there are strong trends underlying this movement. These include the need for building strategic relationships, focusing on total cost and strategic cost reduction, yet collaborating and integrating with suppliers. While in the past these efforts may have appeared to be contradictory, with proper strategic planning they can be complementary. Originality/value Supply managers of the future need to acquire strategic skills that add value and enable effective alignment with key business functions at a senior decision‐making level. Additional research is needed in the area to determine how best to recruit and train managers in these skills to move forward. DA - 2006/// PY - 2006/// DO - 10.1108/01443570610672257 VL - 26 IS - 7 SP - 822-844 SN - 1758-6593 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33745317995&partnerID=MN8TOARS KW - skills KW - knowledge management KW - supply KW - delphi method KW - strategic management KW - supply chain management ER - TY - JOUR TI - Preconditioned iterative methods on sparse subspaces AU - Ito, Kazufumi AU - Toivanen, Jari T2 - APPLIED MATHEMATICS LETTERS AB - When some rows of the system matrix and a preconditioner coincide, preconditioned iterations can be reduced to a sparse subspace. Taking advantage of this property can lead to considerable memory and computational savings. This is particularly useful with the GMRES method. We consider the iterative solution of a discretized partial differential equation on this sparse subspace. With a domain decomposition method and a fictitious domain method the subspace corresponds a small neighborhood of an interface. As numerical examples we solve the Helmholtz equation using a fictitious domain method and an elliptic equation with a jump in the diffusion coefficient using a separable preconditioner. DA - 2006/11// PY - 2006/11// DO - 10.1016/j.aml.2005.11.027 VL - 19 IS - 11 SP - 1191-1197 SN - 0893-9659 KW - subspace iteration KW - preconditioning KW - Krylov subspace method KW - domain decomposition method KW - fictitious domain method KW - interface problem ER - TY - JOUR TI - On the value of static analysis for fault detection in software AU - Zheng, J AU - Williams, L AU - Nagappan, N AU - Snipes, W AU - Hudepohl, JP AU - Vouk, MA T2 - IEEE TRANSACTIONS ON SOFTWARE ENGINEERING AB - No single software fault-detection technique is capable of addressing all fault-detection concerns. Similarly to software reviews and testing, static analysis tools (or automated static analysis) can be used to remove defects prior to release of a software product. To determine to what extent automated static analysis can help in the economic production of a high-quality product, we have analyzed static analysis faults and test and customer-reported failures for three large-scale industrial software systems developed at Nortel Networks. The data indicate that automated static analysis is an affordable means of software fault detection. Using the orthogonal defect classification scheme, we found that automated static analysis is effective at identifying assignment and checking faults, allowing the later software production phases to focus on more complex, functional, and algorithmic faults. A majority of the defects found by automated static analysis appear to be produced by a few key types of programmer errors and some of these types have the potential to cause security vulnerabilities. Statistical analysis results indicate the number of automated static analysis faults can be effective for identifying problem modules. Our results indicate static analysis tools are complementary to other fault-detection techniques for the economic production of a high-quality software product. DA - 2006/4// PY - 2006/4// DO - 10.1109/TSE.2006.38 VL - 32 IS - 4 SP - 240-253 SN - 1939-3520 KW - code inspections KW - walkthroughs ER - TY - JOUR TI - Note on a linear difference equation AU - Hartwig, RE T2 - AMERICAN MATHEMATICAL MONTHLY DA - 2006/3// PY - 2006/3// DO - 10.2307/27641892 VL - 113 IS - 3 SP - 250-256 SN - 0002-9890 ER - TY - BOOK TI - Modeling and simulation in Scilab/Scicos AU - Campbell, S. AU - Chancelier, J.-P. AU - Nikoukhah, R. DA - 2006/// PY - 2006/// PB - New York: Springer SN - 0387278028 ER - TY - JOUR TI - Material surface design to counter electromagnetic interrogation of targets AU - Banks, HT AU - Ito, K AU - Kepler, GM AU - Toivanen, JA T2 - SIAM JOURNAL ON APPLIED MATHEMATICS AB - Utilization of controllable ferromagnetic layers coating a conducting object to provide an attenuation capability against electromagnetic interrogation is discussed. The problem is formulated as a differential game and/or a robust optimization. The scattered field due to interrogation can be attenuated with the assumption of an uncertainty in the interrogation wave numbers. The controllable layer composed of ferromagnetic materials [H. How and C. Vittoria, Implementation of Microwave Active Nulling, private communication; H. How and C. Vittoria, IEEE Trans. Microwave Theory Tech., 52 (2004), pp. 2177-2182] is incorporated in a mathematical formulation based on the time-harmonic Maxwell equation. Fresnel's law for the reflectance index is extended to the electromagnetic propagation in anisotropic composite layers of ferromagnetic and electronic devices and is used to demonstrate feasibility of control of reflections. Our methodology is also tested for a nonplanar geometry of the conducting object (an NACA airfoil) in which we report our findings in the form of reduced radar cross sections (RCS)\@. DA - 2006/// PY - 2006/// DO - 10.1137/040621430 VL - 66 IS - 3 SP - 1027-1049 SN - 1095-712X KW - electromagnetic KW - inverse scattering KW - attenuation ER - TY - JOUR TI - Integrated modeling of information and physical flows in transportation systems AU - Cetin, Mecit AU - List, George F. T2 - TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES AB - Modeling transportation systems operations in large part involves an understanding of how physical entities (i.e., vehicles) move and interact with each other in the system. Transportation systems that are integrated with information technologies involve flow of information besides the flow of physical entities. In some cases, a unified modeling approach that considers both flows is needed to create an accurate model for system operations. This paper highlights the significance of such a modeling approach that involves an explicit representation of information flow attributes (e.g., response time and information delay). Several small-scale queuing models are developed to illustrate the importance of incorporating information flow related attributes into the models of transportation systems operations. In each example system, two scenarios are considered: modeling the given system with or without explicitly representing the information flow. Comparison of performance statistics is made between these two scenarios. It is found that ignoring information flows may lead to significant inaccuracies in the estimates of the system performance. DA - 2006/4// PY - 2006/4// DO - 10.1016/j.trc.2006.06.003 VL - 14 IS - 2 SP - 139-156 SN - 0968-090X KW - intelligent transportation systems KW - information flow KW - performance modeling KW - correlation ER - TY - JOUR TI - Efficient implementation algorithms for homogenized energy models AU - Braun, Thomas R. AU - Smith, Ralph C. T2 - CONTINUUM MECHANICS AND THERMODYNAMICS AB - The homogenized energy framework quantifying ferroelectric and ferromagnetic hysteresis is increasingly used for comprehensive material characterization and model-based control design. For operating regimes in which thermal relaxation mechanisms and stress-dependencies are negligible, existing algorithms are sufficiently efficient to permit device optimization and the potential for real-time control implementation. In this paper, we develop algorithms employing lookup tables which permit the high speed implementation of formulations which incorporate relaxation mechanisms and electromechanical coupling. Aspects of the algorithms are illustrated through comparison with experimental data. DA - 2006/9// PY - 2006/9// DO - 10.1007/s00161-006-0015-8 VL - 18 IS - 3-4 SP - 137-155 SN - 0935-1175 ER - TY - JOUR TI - Convergence analysis of a PageRank updating algorithm by Langville and Meyer AU - Ipsen, ICF AU - Kirkland, S T2 - SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS AB - The PageRank updating algorithm proposed by Langville and Meyer is a special case of an iterative aggregation/disaggregation (SIAD) method for computing stationary distributions of very large Markov chains. It is designed, in particular, to speed up the determination of PageRank, which is used by the search engine Google in the ranking of web pages. In this paper the convergence, in exact arithmetic, of the SIAD method is analyzed. The SIAD method is expressed as the power method preconditioned by a partial LU factorization. This leads to a simple derivation of the asymptotic convergence rate of the SIAD method. It is known that the power method applied to the Google matrix always converges, and we show that the asymptotic convergence rate of the SIAD method is at least as good as that of the power method. Furthermore, by exploiting the hyperlink structure of the web it can be shown that the asymptotic convergence rate of the SIAD method applied to the Google matrix can be made strictly faster than that of the power method. DA - 2006/// PY - 2006/// DO - 10.1137/S0895479804439808 VL - 27 IS - 4 SP - 952-967 SN - 1095-7162 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33646455491&partnerID=MN8TOARS KW - Google KW - PageRank KW - Markov chain KW - power method KW - stochastic complement KW - aggregation/disaggregation ER - TY - JOUR TI - Construction and experimental implementation of a model-based inverse filter to attenuate hysteresis in ferroelectric transducers AU - Hatch, Andrew G. AU - Smith, Ralph C. AU - De, Tathagata AU - Salapaka, Murti V. T2 - IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY AB - Hysteresis and constitutive nonlinearities are inherent properties of ferroelectric transducer materials due to the noncentrosymmetric nature of the compounds. In certain regimes, these effects can be mitigated through restricted input fields, charge- or current-controlled amplifiers, or feedback designs. For general operating conditions, however, these properties must be accommodated in models, transducer designs, and model-based control algorithms to achieve the novel capabilities provided by the compounds. In this paper, we illustrate the construction of inverse filters, based on homogenized energy models, which can be used to approximately linearize the piezoceramic transducer behavior for linear design and control implementation. Attributes of the inverse filters are illustrated through numerical examples and experimental open loop control implementation for an atomic force microscope stage DA - 2006/11// PY - 2006/11// DO - 10.1109/TCST.2006.883195 VL - 14 IS - 6 SP - 1058-1069 SN - 1558-0865 KW - atomic force microscopy (AFM) KW - control systems KW - dielectric hysteresis KW - ferroelectric devices KW - modeling ER - TY - JOUR TI - An augmented approach for the pressure boundary condition in a Stokes flow AU - Li, Z. L. AU - Wan, X. H. AU - Ito, K. AU - Lubkin, S. R. T2 - Communications in Computational Physics DA - 2006/// PY - 2006/// VL - 1 IS - 5 SP - 874-885 ER - TY - JOUR TI - An adaptive cyberinfrastructure for threat management in urban water distribution systems AU - Mahinthakumar, K. AU - Von Laszewski, G. AU - Ranjithan, R. AU - Brill, D. AU - Uber, J. AU - Harrison, K. AU - Sreepathi, S. AU - Zechman, E. T2 - Computational Science - ICCS 2006, Pt. 3, Proceedings AB - Threat management in drinking water distribution systems involves real-time characterization of any contaminant source and plume, design of control strategies, and design of incremental data sampling schedules. This requires dynamic integration of time-varying measurements along with analytical modules that include simulation models, adaptive sampling procedures, and optimization methods. These modules are compute-intensive, requiring multi-level parallel processing via computer clusters. Since real-time responses are critical, the computational needs must also be adaptively matched with available resources. This requires a software system to facilitate this integration via a high-performance computing architecture such that the measurement system, the analytical modules and the computing resources can mutually adapt and steer each other. This paper describes the development of such an adaptive cyberinfrastructure system facilitated by a dynamic workflow design. DA - 2006/// PY - 2006/// DO - 10.1007/11758532_54 VL - 3993 SP - 401-408 ER - TY - JOUR TI - A wavelet-based spectral procedure for steady-state simulation analysis AU - Lada, Emily K. AU - Wilson, James R. T2 - EUROPEAN JOURNAL OF OPERATIONAL RESEARCH AB - We develop WASSP, a wavelet-based spectral method for steady-state simulation analysis. First WASSP determines a batch size and a warm-up period beyond which the computed batch means form an approximately stationary Gaussian process. Next WASSP computes the discrete wavelet transform of the bias-corrected log-smoothed-periodogram of the batch means, using a soft-thresholding scheme to denoise the estimated wavelet coefficients. Then taking the inverse discrete wavelet transform of the thresholded wavelet coefficients, WASSP computes estimators of the batch means log-spectrum and the steady-state variance parameter (i.e., the sum of covariances at all lags) for the original (unbatched) process. Finally by combining the latter estimator with the batch means grand average, WASSP provides a sequential procedure for constructing a confidence interval on the steady-state mean that satisfies user-specified requirements concerning absolute or relative precision as well as coverage probability. An experimental performance evaluation demonstrates WASSP’s effectiveness compared with other simulation analysis methods. DA - 2006/11/1/ PY - 2006/11/1/ DO - 10.1016/j.ejor.2005.04.025 VL - 174 IS - 3 SP - 1769-1801 SN - 0377-2217 KW - simulation KW - steady-state analysis KW - spectral method KW - time series KW - wavelet analysis ER - TY - JOUR TI - A state-dependent Riccati equation-based estimator approach for HIV feedback control AU - Banks, HT AU - Kwon, HD AU - Toivanen, JA AU - Tran, HT T2 - OPTIMAL CONTROL APPLICATIONS & METHODS AB - Abstract We consider optimal dynamic multidrug therapies for human immunodeficiency virus (HIV) type 1 infection. In this context, we describe an optimal tracking problem attempting to drive the states of the system to a stationary state in which the viral load is low and the immune response is strong. We consider optimal feedback control with full‐state as well as with partial‐state measurements. In the case of partial‐state measurement, a state estimator is constructed based on viral load and T‐cell count measurements. We demonstrate by numerical simulations that by anticipation of and response to the disease progression, the dynamic multidrug strategy reduces the viral load, increases the CD4+ T‐cell count and improves the immune response. Copyright © 2006 John Wiley & Sons, Ltd. DA - 2006/// PY - 2006/// DO - 10.1002/oca.773 VL - 27 IS - 2 SP - 93-121 SN - 1099-1514 KW - multidrug therapies KW - feedback control KW - estimator KW - HIV model KW - SDRE ER - TY - JOUR TI - A reordering for the PageRank problem AU - Langville, AN AU - Meyer, CD T2 - SIAM JOURNAL ON SCIENTIFIC COMPUTING AB - We describe a reordering particularly suited to the PageRank problem, which reduces the computation of the PageRank vector to that of solving a much smaller system and then using forward substitution to get the full solution vector. We compare the theoretical rates of convergence of the original PageRank algorithm to that of the new reordered PageRank algorithm, showing that the new algorithm can do no worse than the original algorithm. We present results of an experimental comparison on five datasets, which demonstrate that the reordered PageRank algorithm can provide a speedup of as much as a factor of 6. We also note potential additional benefits that result from the proposed reordering. DA - 2006/// PY - 2006/// DO - 10.1137/040607551 VL - 27 IS - 6 SP - 2112-2120 SN - 1095-7197 KW - Markov chains KW - PageRank KW - reorderings KW - power method KW - convergence KW - stationary vector KW - dangling nodes ER - TY - JOUR TI - A homogenization model for laser beam-induced current imaging and detection of non-uniformities in semiconductor arrays AU - Fang, Weifu AU - Ito, Kazufumi AU - Redfern, David A. T2 - JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS AB - We present an approximate model for laser beam-induced current (LBIC) imaging of arrays of semiconductor devices based on homogenization. LBIC is a non-destructive technique useful for the characterization and quality control of semiconductor focal plane arrays, a key component in modern imaging systems. The model provides not only an efficient alternative for LBIC image simulation of large uniform arrays, but also an effective method for detection of non-uniformities among arrays. Numerical examples are presented to illustrate the effectiveness of this method in detecting array non-uniformities due to variations in dislocation/size or doping level among p–n junction diodes. DA - 2006/10/1/ PY - 2006/10/1/ DO - 10.1016/j.cam.2005.08.007 VL - 194 IS - 2 SP - 395-408 SN - 1879-1778 KW - semiconductor arrays KW - laser beam-induced current KW - LBIC KW - homogenization KW - inverse problems ER - TY - JOUR TI - Traffic grooming in path, star, and tree networks: Complexity, bounds, and algorithms AU - Huang, Shu AU - Dutta, Rudra AU - Rouskas, George N. T2 - IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS DA - 2006/4// PY - 2006/4// DO - 10.1109/jsac-ocn.2006.04006 VL - 24 IS - 4 SP - 66-82 SN - 1558-0008 KW - optical KW - networks KW - networking KW - traffic grooming KW - virtual topology ER - TY - JOUR TI - The state of JOM: An outgoing editor's (retro)spective AU - Handfield, Robert T2 - JOURNAL OF OPERATIONS MANAGEMENT AB - Five years ago, as the new Editor-in-Chief for the Journal of Operations Management, I wrote an editorial that identified what I believed were the important characteristics for authors to consider in submitting their research to the Journal of Operations Management (Handfield, 2002). I reflected upon where the field of Operations Management had been, where we were, and the challenges that lay ahead. I was very honest in sharing my own set of personal biases on research that influences my decision-making in the acceptance or rejection of submissions to JOM. Cross-functional and cross-enterprise decision-making. Research that reflects management challenges associated with cross-functional and cross-enterprise decision-making when approaching management problems. Methodological rigor and the scientific method. Researchers must explore relevant research questions, so long as they adhere to proven scientific methods of investigation. I sought to publish research that was based on solid empirical methodologies based on the scientific method, but which could use a number of diverse research approaches (structured and unstructured interviews, coding and matrix analysis), meta-analysis, critical event techniques, simulation, quasi-experiments, lab studies, and data collection using the World Wide Web. Managerial relevance. The third important theme in my editorial outlook was to only publish articles that were managerially relevant. I urged researchers to develop an intimate understanding of the problems facing Operations Management practitioners. Managers are now more interested in understanding what factors, for example, affect the successful deployment of new technologies involving coordination between multiple organizations, or how to measure and manage strategic alliances with these parties. They are seeking how to deploy global manufacturing facilities, and create multi-echelon distribution systems that support inter-organizational sharing of demand and product requirements. In stipulating these criteria, I did not mean to imply that articles which did not meet these criteria were not relevant or worthwhile, only that they were unlikely to end up being published in the Journal of Operations Management under my editorship over my 5-year tenure. So … were these lofty goals indeed achieved? Was this view unnecessarily biased and narrow, and would it bring the journal down? Fortunately no. In large part, I believe this focus was the right one. First, the good news. JOM has grown significantly in stature and recognition in the last 5 years, due in large part to the early work done by Jack Meredith in shaping the focus of the journal prior to my editorship, and which I was able to sustain to date. The submission rate for JOM has grown steadily—in 2002 it was around 150 per year, then 180 last year in 2003. In 2004, we reviewed over 250 submissions, and in 2005, with a number of special issues, over 300 manuscripts were submitted to JOM—a truly incredible number. This trend continues into 2006, and we are seeing submissions from every part of the globe. JOM has truly evolved into a Global Journal of Operations Management, with authors submitting from Europe, South America, Latin America, Hong Kong, China, India, the Middle East, and even Africa! I sought to also expand the international presence in the Associate Editor Board. In addition to our existing representatives from universities in Australia and IMD, I invited several new AE's to the board, including Paul Cousins (University of Manchester), Kate Blackmon (Oxford University), Cipriano Forza (Universita di Modena e Reggio Emilia), Jan C. Fransoo (Eindhoven), Dirk Van Donk (University of Groningen), and others. We are also beginning to include a number of manuscripts from Chinese authors, via a special process designed by Elsevier to this end. The large number of special issues managed by Guest Editors also reflects the interesting and diverse set of topics that were published in the journal. These special issue Guest Editors did a wonderful job in pulling together a cohesive set of impactful research papers that reflect the cutting-edge nature of the field, and the breadth of these issues reflects the current trends we face in the field of Operations Management: The Build to Order Supply Chain (BOSC): A Competitive Strategy for 21st Century Guest Editor: Angappa Gunasekaran, Associate Professor of Operations Management Incorporating Behavioral Theory in OM Empirical Models Guest Editors: Elliot Bendoly and Ken Schultz How eBusiness Technologies Impact Supply Chain Operations? Special Issue Editors: Professor Tonya Boone, College of William & Mary Professor, College of William & Mary Supply Chain Management in a Sustainable Environment Guest Editors: Vaidy Jayaraman, School of Business, University of Miami Jonathan Linton, Lally School of Management & Technology, Rensselaer Polytechnic Institute Associate Guest Editor: Robert Klassen, Richard Ivey School of Business, University of Western Ontario Evolution of the Field of Operations Management Guest Editor: Dr. Linda G. Sprague, FDSI, FIOM, Professor of Manufacturing and Operations Management, China Europe International Business School (CEIBS), Shanghai, The People's Republic of China Operations Management in Not-For-Profit, Public and Government Services Guest Editors: Rohit Verma, University of Utah Curtis McLaughlin, University of North Carolina, Chapel Hill Robert Johnston, University of Warwick William Youngdahl, Thunderbird, The American Graduate School of International Management Offshoring of Service and Knowledge Work Guest Editors: William Youngdahl, Thunderbird, The Garvin School of International Management Kannan Ramaswamy, Thunderbird, The Garvin School of International Management Rohit Verma, University of Utah Organization Theory and Supply Chain Management Guest Editors: David J. Ketchen, Jr., Carl DeSantis Professor of Management, Florida State University G. Tomas M. Hult, Director—MSU-CIBER, Michigan State University Operations Management Research in Process Industries Guest Editors: Jan C. Fransoo (Technische Universiteit Eindhoven, The Netherlands) Dirk Pieter Van Donk (University of Groningen, The Netherlands) OM Replication Research Guest Editors: Mark Frohlich, Assistant Professor, Boston University J. Robb Dixon, Associate Professor, Boston University Risk Issues in Supply Chain Management Guest Editors: Ram Narasimhan, Professor, Michigan State University Srinivas Talluri, Professor, Michigan State University Research in Supply Chain Quality Guest Editor: S. Thomas Foster, Jr., Associate Professor, Brigham Young University Innovative Data Sources for Empirically Building and Validating Theories in OM Guest Editors: Diane H. Parente (Penn State Erie) Thomas F. Gattiker (Miami University) Coordinating Product Design, Process Design, and Supply Chain Design Decisions Guest Editors: M. Johnny Rungtusanatham, Associate Professor, Arizona State University Cipriano Forza, Associate Professor, Università di Padova Part of the explanation for this growth in submissions is due to the increasing visibility of JOM as one of the top tier journals in the field of Operations and Supply Chain Management. In addition to being listed in the Financial Times top 40 academic journals used to rank business schools, JOM has seen a significant jump in its “Impact Factor”. The impact factor is a measure based on the citation index, identifying the extent to which a journal is cited in all other journals. The impact factor is calculated by dividing the number of citations in the current year to articles published in the two previous years by the total number of articles published in the two previous years. The example below shows how it is calculated. The annual Best Paper Award has now become a feature event at the Academy of Management Operations Management Division meeting. One of the sessions is dedicated to presenting the JOM best paper, best reviewer, and best Associate Editor awards next year. Three paper finalists present their paper to the group, and the award is announced immediately after the session. Another new feature is the introduction of a new section of the journal, entitled “Theory Development”. This section of the journal was dedicated to the development of theory which forms the basis for solid empirical research and theory-testing. The Theory Development section of the journal was not simply designed to include literature reviews, but was focused on the publications of research that advances the theoretical foundation of operations management as a basis for future theory-testing. Criteria for evaluation of papers in this section is similar to the criteria used in the Academy of Management Review, but modified as follows. The Theory Development section of the journal is devoted to theory development for operations management scholars around the world. The mission of this section is to publish new theoretical insights that advance our understanding of operations management. Theory Development-JOM will publish novel, insightful and carefully crafted conceptual articles that challenge conventional wisdom concerning all aspects of operations management and its evolution as a field of knowledge. The journal is open to a variety of perspectives, including those that seek to improve the effectiveness of, as well as those critical of operations management. Each manuscript published in this section must provide new theoretical insights that can advance our understanding of the problems and solutions available to operations managers and the operations function. Most articles include a review of relevant literature as well. Submissions to this section must extend theory in ways that permit the development of testable, knowledge-based claims. To do this, researchers can develop new management and operations management theory, significantly challenge or clarify existing theory, synthesize recent advances and ideas into fresh if not entirely new theory, or initiate a search for new theory by identifying and delineating a novel theoretical problem. Theory-building models should also be well grounded, and address actual management practices. The editors will also encourage cross-fertilization with other fields by borrowing concepts from them: contributions are often grounded in economics, psychology, sociology, or social psychology, as well as the humanities, history, engineering, physics, mathematics, and nontraditional perspectives. Finally, a note to all of you who keep up with the evolution of the field of management. Many people were saddened by the death a year ago of Sumantra Ghoshal, a brilliant author of many works on competitive strategy. One of the last papers he wrote was titled “Bad Management Theories are Destroying Good Management Practices.” In his paper, he emphasizes the heavy responsibility borne by business school academics, who in the past have propagated ideologically inspired amoral theories, and who then freed their students from any sense of moral responsibility. He advocates that many of the traditional theoretical foundations including transaction cost theory, Porter's theory of the firm, and the behavioral theory of the firm may have in fact hindered effective decision-making by managers trained in these theories. I mention this article only to remind you of the responsibility you bear in helping to share the discipline of Operations Management, and the way that it will shape the thinking of future managers trained by the readers of our journal. I am confident that the new editorial team of Morgan Swink and Ken Boyer will successfully carry on this mission, and feel confident in leaving the journal in their highly capable hands. DA - 2006/9// PY - 2006/9// DO - 10.1016/j.jom.2006.07.002 VL - 24 IS - 5 SP - 417-420 SN - 0272-6963 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33747891682&partnerID=MN8TOARS ER - TY - JOUR TI - Performance evaluation of recent procedures for steady-state simulation analysis AU - Lada, Emily K. AU - Steiger, Natalie M. AU - Wilson, James R. T2 - IIE TRANSACTIONS AB - The performance of the batch-means procedure ASAP3 and the spectral procedure WASSP is evaluated on test problems with characteristics typical of practical applications of steady-state simulation analysis procedures. ASAP3 and WASSP are sequential procedures designed to produce a confidence-interval estimator for the mean response that satisfies user-specified half-length and coverage-probability requirements. ASAP3 is based on an inverse Cornish-Fisher expansion for the classical batch-means t-ratio, whereas WASSP is based on a wavelet estimator of the batch-means power spectrum. Regarding closeness of the empirical coverage probability and average half-length of the delivered confidence intervals to their respective nominal levels, both procedures compared favorably with the Law-Carson procedure and the original ASAP algorithm. Regarding the average sample sizes required for decreasing levels of maximum confidence-interval half-length, ASAP3 and WASSP exhibited reasonable efficiency in the test problems. DA - 2006/9// PY - 2006/9// DO - 10.1080/07408170600735520 VL - 38 IS - 9 SP - 711-727 SN - 1545-8830 ER - TY - JOUR TI - Parabolic variational inequalities: The Lagrange multiplier approach AU - Ito, K AU - Kunisch, K T2 - JOURNAL DE MATHEMATIQUES PURES ET APPLIQUEES AB - Parabolic variational inequalities are discussed and existence and uniqueness of strong as well as weak solutions are established. Our approach is based on a Lagrange multiplier treatment. Existence is obtained as the unique asymptotic limit of solutions to a family of appropriately regularized nonlinear parabolic equations. Two regularization techniques are presented resulting in feasible and unfeasible approximations respectively. Monotonicity results of the regularized solutions and convergence rate estimate are established. The results are applied to the Black–Scholes model for American options. The case of the bilateral constraints is also treated. Numerical results for the Black–Scholes model are presented and prove the practical efficiency of our results. Des inégalités variationnelles paraboliques sont discutées et l'existence et l'unicité des solutions fortes faibles sont établies. Notre approche des solutions utilise une méthode de multiplicateur de Lagrange. L'existence est obtenue comme limite asymptotique unique des solutions à une famille d'équations paraboliques non linéaires convenablement régularisées. Deux techniques de régularisation sont présentées ayant pour résultat des approximations acceptées ou rejetées. Des résultats de monotonie des solutions régularisées et d'évaluation de taux de convergence sont établis. Les résultats sont appliqués au modèle Black–Scholes pour des options américaines. Le cas des contraintes bilatérales est également traité. Des résultats numériques pour le modèle Black–Scholes sont présentés et prouvent l'efficacité pratique de nos techniques. DA - 2006/3// PY - 2006/3// DO - 10.1016/j.matpur.2005.08.005 VL - 85 IS - 3 SP - 415-449 SN - 1776-3371 KW - parabolic variational inequalities KW - Lagrange multipliers KW - feasible and unfeasible regularization KW - Black-Scholes ER - TY - JOUR TI - Optimal design of redundant water distribution networks using a cluster of workstations AU - Kumar, S. V. AU - Doby, T. A. AU - Baugh, J. W. AU - Brill, E. D. AU - Ranjithan, S. R. T2 - Journal of Water Resources Planning and Management AB - A genetic algorithm (GA)-based method for the least-cost design of looped pipe networks for various levels of redundancy is presented in this paper. Redundancy constraints are introduced in the optimization model by considering the number of pipes assumed to be out of service at any one time. Using this approach, trade-off relationships between cost and redundancy are developed. The GA-based approach is computationally intensive, and implementations on a custom fault-tolerant distributed computing framework, called Vitri, are used to satisfy the computational requirements. The design methodology is applied to two water distribution networks of different sizes, and a comparison of the performance of the distributed GAs for the design problems is also presented. We conclude that a GA-based approach to obtaining cost-effective, redundant solutions for the least-cost design of looped pipe networks can be effectively used on a heterogeneous network of nondedicated workstations. DA - 2006/// PY - 2006/// DO - 10.1061/(ASCE)0733-9496(2006)132:5(374) VL - 132 IS - 5 SP - 374-384 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33747304468&partnerID=MN8TOARS ER - TY - JOUR TI - Modeling baroreflex regulation of heart rate during orthostatic stress AU - Olufsen, Mette S. AU - Tran, Hien T. AU - Ottesen, Johnny T. AU - Lipsitz, Lewis A. AU - Novak, Vera T2 - AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY AB - During orthostatic stress, arterial and cardiopulmonary baroreflexes play a key role in maintaining arterial pressure by regulating heart rate. This study presents a mathematical model that can predict the dynamics of heart rate regulation in response to postural change from sitting to standing. The model uses blood pressure measured in the finger as an input to model heart rate dynamics in response to changes in baroreceptor nerve firing rate, sympathetic and parasympathetic responses, vestibulo-sympathetic reflex, and concentrations of norepinephrine and acetylcholine. We formulate an inverse least squares problem for parameter estimation and successfully demonstrate that our mathematical model can accurately predict heart rate dynamics observed in data obtained from healthy young, healthy elderly, and hypertensive elderly subjects. One of our key findings indicates that, to successfully validate our model against clinical data, it is necessary to include the vestibulo-sympathetic reflex. Furthermore, our model reveals that the transfer between the nerve firing and blood pressure is nonlinear and follows a hysteresis curve. In healthy young people, the hysteresis loop is wide, whereas, in healthy and hypertensive elderly people, the hysteresis loop shifts to higher blood pressure values, and its area is diminished. Finally, for hypertensive elderly people, the hysteresis loop is generally not closed, indicating that, during postural change from sitting to standing, baroreflex modulation does not return to steady state during the first minute of standing. DA - 2006/11// PY - 2006/11// DO - 10.1152/ajpregu.00205.2006 VL - 291 IS - 5 SP - R1355-R1368 SN - 1522-1490 KW - mathematical modeling KW - heart rate control KW - baroreflex function KW - sympathetic and parasympathetic responses KW - vestibulo-sympathetic reflex ER - TY - BOOK TI - Incorporating commitment protocols into Tropos AU - Mallya, A.U. AU - Singh, Munindar P. AB - This paper synthesizes two trends in the engineering of agent-based systems. One, modern agent-oriented methodologies deal with the key aspects of software development including requirements acquisition, architecture, and design, but can benefit from a stronger treatment of flexible interactions. Two, commitment protocols declaratively capture interactions among business partners, thus facilitating flexible behavior and a sophisticated notion of compliance. However, they lack support for engineering concerns such as inducing the desired roles and selecting the right protocols. This paper combines these two directions. For concreteness, we choose the Tropos methodology, which is strong in its requirements analysis, but our results can be ported to other agent-oriented methodologies. Our approach is as follows. First, using Tropos, analyze requirements based on dependencies between actors. Second, select top-level protocols based on the actors’ hard goals, while respecting the logical boundaries of their interactions. Third, select refined protocols based on the actors’ soft goals. Consequently, Tropos provides a rigorous basis for modeling and composing protocols whereas the protocols help produce perspicuous designs that respect the participants’ autonomy. We evaluate our approach using a large existing case. DA - 2006/// PY - 2006/// DO - 10.1007/11752660_6 VL - 3950 LNCS PB - Berlin: Springer SE - 69-80 SN - 3540340971 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33745861698&partnerID=MN8TOARS ER - TY - JOUR TI - Experimental validation of a homogenized energy model for magnetic after-effects AU - Braun, TR AU - Smith, RC AU - Dapino, MJ T2 - APPLIED PHYSICS LETTERS AB - In this letter, we experimentally validate the ability of a recently developed ferromagnetic hysteresis model to characterize magnetic after-effects in ferromagnetic materials. The modeling framework, which combines energy analysis at the lattice level with stochastic homogenization techniques to accommodate material, stress, and field nonhomogeneities, quantifies after-effects through a balance of the Gibbs and relative thermal energies. Attributes of the framework are illustrated through fits to experimental steel data. DA - 2006/3/20/ PY - 2006/3/20/ DO - 10.1063/1.2188595 VL - 88 IS - 12 SP - SN - 1077-3118 ER - TY - JOUR TI - Constructing generalized mean functions using convex functions with regularity conditions AU - Zhao, Yun-Bin AU - Fang, Shu-Cherng AU - Li, Duan T2 - SIAM JOURNAL ON OPTIMIZATION AB - The generalized mean function has been widely used in convex analysis and mathematical programming. This paper studies a further generalization of such a function. A necessary and sufficient condition is obtained for the convexity of a generalized function. Additional sufficient conditions that can be easily checked are derived for the purpose of identifying some classes of functions which guarantee the convexity of the generalized functions. We show that some new classes of convex functions with certain regularity (such as S*-regularity) can be used as building blocks to construct such generalized functions. DA - 2006/// PY - 2006/// DO - 10.1137/040603838 VL - 17 IS - 1 SP - 37-51 SN - 1095-7189 KW - convexity KW - mathematical programming KW - generalized mean function KW - self-concordant functions KW - S*-regular functions ER - TY - JOUR TI - A theoretical approach to characterising setups in batch fabric dyeing operations AU - Cho, Eunkyoung G. AU - Thoney, Kristin A. AU - Krauss, Jeffrey D. T2 - COLORATION TECHNOLOGY AB - Traditionally, most of the research published on dyeing has been on achievements in optimising the mechanical and chemical technology associated with the physical dyeing process. However, relatively little research is available in the area of scheduling dyeing operations. This could be due to a lack of information available about dyeing setups. In this study, a theoretical approach to structuring machine‐cleaning setups in batch fabric dyeing operations based on the CIELAB L*C*h colour space and the tolerance of the human visual system is presented. This will permit more research on the detailed scheduling of dyeing operations that could ultimately help dyeing facilities to better meet the needs of their customers in terms of improving on‐time delivery. DA - 2006/// PY - 2006/// DO - 10.1111/j.1478-4408.2006.00021.x VL - 122 IS - 3 SP - 145-152 SN - 1478-4408 ER - TY - JOUR TI - A population-based latent variable approach for association mapping of quantitative trait loci AU - Wang, T AU - Weir, B AU - Zeng, ZB T2 - ANNALS OF HUMAN GENETICS AB - Summary A population‐based latent variable approach is proposed for association mapping of quantitative trait loci (QTL), using multiple closely linked genetic markers within a small candidate region in the genome. By incorporating QTL as latent variables into a penetrance model, the QTL are flexible to characterize either alleles at putative trait loci or potential risk haplotypes/sub‐haplotypes of the markers. Under a general likelihood framework, we develop an EM‐based algorithm to estimate genetic effects of the QTL and haplotype frequencies of the QTL and markers jointly. Closed form solutions derived in the maximization step of the EM procedure for updating the joint haplotype frequencies of QTL and markers can effectively reduce the computational intensity. Various association measures between QTL and markers can then be derived from the haplotype frequencies of markers and used to infer QTL positions. The likelihood ratio statistic also provides a joint test for association between a quantitative trait and marker genotypes without requiring adjustment for the multiple testing. Extensive simulation studies are performed to evaluate the approach. DA - 2006/7// PY - 2006/7// DO - 10.1111/j.1469-1809.2006.00264.x VL - 70 SP - 506-523 SN - 0003-4800 KW - association mapping KW - maximum likelihood KW - haplotype KW - latent variable KW - EM algorithm ER - TY - JOUR TI - Visual factors affecting touchdown point judgments during off-airport emergency landings AU - Mayer, Celeste M. AU - Mershon, Donald H. AU - Lim, Raymond W. AU - Chipley, M. Ryan AU - McAllister, David F. T2 - INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY AB - This article provides a comprehensive discussion of research designed to examine the possible existence of consistent visual misperceptions that may occur during off-airport emergency landings. The importance of 2 particular visual experiences was evaluated: (a) the view of the world seen from the unusually steep bank at a low altitude, and (b) the visual distraction of a "windmilling" propeller. The influences of experience and environmental structure were also considered. Studies of these factors were conducted using a visually realistic cockpit mounted within a VisionDome® virtual reality environment. Behavioral responses were collected from both naive participants and pilot participants. The findings indicated that judgments of the position of the touchdown point made while the airplane is turning are underestimated in distance, whereas judgments made while the airplane is on a straight approach to the touchdown point are overestimated. In most cases, the windmilling propeller decreased touchdown point judgment accuracy. In addition, pilot experience was associated with improved judgment accuracy during the turning approaches. The presented environmental structure had a weak and inconsistent effect. DA - 2006/// PY - 2006/// DO - 10.1207/s15327108ijap1604_4 VL - 16 IS - 4 SP - 401-418 SN - 1050-8414 ER - TY - JOUR TI - Pattern avoidance in compositions and multiset permutations AU - Savage, CD AU - Wilf, HS T2 - ADVANCES IN APPLIED MATHEMATICS AB - We show that among the compositions of n into positive parts, the number g(n) that avoid a given pattern π of three letters is independent of π. We find the generating function of {g(n)}, and it shows that the sequence {g(n)} is not P-recursive. If S is a given multiset, we show that the number of permutations of S that avoid a pattern π of three letters is independent of π. Finally, we give a bijective proof of the fact that if M=1a1…kak is a given multiset then the number of permutations of M that avoid the pattern (123) is a symmetric function of the multiplicities a1,…,ak. The bijection uses the Greene–Kleitman symmetric chain decomposition of the Boolean lattice. DA - 2006/2// PY - 2006/2// DO - 10.1016/j.aam.2005.06.003 VL - 36 IS - 2 SP - 194-201 SN - 1090-2074 ER - TY - JOUR TI - Parallel parameter study of the Wigner-Poisson equations for RTDs AU - Lasater, M. S. AU - Kelley, C. T. AU - Salinger, A. G. AU - Woolard, D. L. AU - Zhao, P. T2 - COMPUTERS & MATHEMATICS WITH APPLICATIONS AB - We will discuss a parametric study of the solution of the Wigner-Poisson equations for resonant tunneling diodes. These structures exhibit self-sustaining oscillations in certain operating regimes. We will describe the engineering consequences of our study and how it is a significant advance from some previous work, which used much coarser grids. We use LOCA and other packages in the Trilinos framework from Sandia National Laboratory to enable efficient parallelization of the solution methods and to perform bifurcation analysis of this model. We report on the parallel efficiency and scalability of our implementation. DA - 2006/6// PY - 2006/6// DO - 10.1016/j.camwa.2006.05.006 VL - 51 IS - 11 SP - 1677-1688 SN - 1873-7668 KW - Wigner-Poisson equation KW - resonant tunneling diode KW - continuation KW - LOCA KW - scalability ER - TY - JOUR TI - Nonstationary analysis of circuit-switched communication networks AU - Alnowibet, Khalid Abdulaziz AU - Perros, Harry T2 - PERFORMANCE EVALUATION AB - Circuit-switched communication networks have been analyzed extensively in the stationary case, i.e. where the arrival and/or service rates are independent of time. In this paper, we study a circuit-switched network where the rates of external arrivals at the network are time-dependent functions. The circuit-switched network is modelled as a nonstationary queueing network with population constraints, which is analyzed approximately in order to obtain the blocking probability functions. Using this method we model two circuit-switched networks, namely, a traffic-groomed tandem optical network and a single-orbit LEO satellite network. DA - 2006/10// PY - 2006/10// DO - 10.1016/j.peva.2005.10.001 VL - 63 IS - 9-10 SP - 892-909 SN - 1872-745X KW - queueing networks KW - nonstationary arrivals KW - circuit-switched networks KW - traffic grooming KW - LEO satellite networks ER - TY - JOUR TI - Multiple-interval mapping for ordinal traits AU - Li, Jian AU - Wang, Shengchu AU - Zeng, Zhao-Bang T2 - GENETICS AB - Many statistical methods have been developed to map multiple quantitative trait loci (QTL) in experimental cross populations. Among these methods, multiple-interval mapping (MIM) can map QTL with epistasis simultaneously. However, the previous implementation of MIM is for continuously distributed traits. In this study we extend MIM to ordinal traits on the basis of a threshold model. The method inherits the properties and advantages of MIM and can fit a model of multiple QTL effects and epistasis on the underlying liability score. We study a number of statistical issues associated with the method, such as the efficiency and stability of maximization and model selection. We also use computer simulation to study the performance of the method and compare it to other alternative approaches. The method has been implemented in QTL Cartographer to facilitate its general usage for QTL mapping data analysis on binary and ordinal traits. DA - 2006/7// PY - 2006/7// DO - 10.1534/genetics.105.054619 VL - 173 IS - 3 SP - 1649-1663 SN - 0016-6731 ER - TY - JOUR TI - Memory-efficient Kronecker algorithms with applications to the modelling of parallel systems AU - Benoit, Anne AU - Plateau, Brigitte AU - Stewart, William J. T2 - FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE AB - We present a new algorithm for computing the solution of large Markov chain models whose generators can be represented in the form of a generalized tensor algebra, such as networks of stochastic automata. The tensor structure inherently involves a product state space but, inside this product state space, the actual reachable state space can be much smaller. For such cases, we propose an improvement of the standard numerical algorithm, the so-called “shuffle algorithm”, which necessitates only vectors of the size of the actual state space. With this contribution, numerical algorithms based on tensor products can now handle larger models. DA - 2006/8// PY - 2006/8// DO - 10.1016/j.future.2006.02.006 VL - 22 IS - 7 SP - 838-847 SN - 1872-7115 KW - large and sparse Markov chains KW - stochastic automata networks KW - generalized tensor algebra KW - vector-descriptor multiplication KW - shuffle algorithm ER - TY - JOUR TI - Integrating XML data sources using approximate joins AU - Guha, Sudipto AU - Jagadish, H. V. AU - Koudas, Nick AU - Srivastava, Divesh AU - Yu, Ting T2 - ACM TRANSACTIONS ON DATABASE SYSTEMS AB - XML is widely recognized as the data interchange standard of tomorrow because of its ability to represent data from a variety of sources. Hence, XML is likely to be the format through which data from multiple sources is integrated. In this article, we study the problem of integrating XML data sources through correlations realized as join operations. A challenging aspect of this operation is the XML document structure. Two documents might convey approximately or exactly the same information but may be quite different in structure. Consequently, an approximate match in structure, in addition to content, has to be folded into the join operation. We quantify an approximate match in structure and content for pairs of XML documents using well defined notions of distance. We show how notions of distance that have metric properties can be incorporated in a framework for joins between XML data sources and introduce the idea of reference sets to facilitate this operation. Intuitively, a reference set consists of data elements used to project the data space. We characterize what constitutes a good choice of a reference set, and we propose sampling-based algorithms to identify them. We then instantiate our join framework using the tree edit distance between a pair of trees. We next turn our attention to utilizing well known index structures to improve the performance of approximate XML join operations. We present a methodology enabling adaptation of index structures for this problem, and we instantiate it in terms of the R-tree. We demonstrate the practical utility of our solutions using large collections of real and synthetic XML data sets, varying parameters of interest, and highlighting the performance benefits of our approach. DA - 2006/3// PY - 2006/3// DO - 10.1145/1132863.1132868 VL - 31 IS - 1 SP - 161-207 SN - 1557-4644 KW - algorithms KW - experimentation KW - performance KW - theory KW - data integration KW - tree edit distance KW - XML KW - joins KW - approximate joins ER - TY - JOUR TI - Determination of interrogating frequencies to maximize electromagnetic backscatter from objects with material coatings AU - Banks, H. T. AU - Ito, K. AU - Toivanen, J. T2 - Communications in Computational Physics DA - 2006/// PY - 2006/// VL - 1 IS - 2 SP - 362-382 ER - TY - JOUR TI - A homogenized energy framework for ferromagnetic hysteresis AU - Smith, Ralph C. AU - Dapino, Marcelo J. AU - Braun, Thomas R. AU - Mortensen, Anthony P. T2 - IEEE TRANSACTIONS ON MAGNETICS AB - In this paper, we develop a macroscopic framework quantifying the hysteresis and constitutive nonlinearities inherent to ferromagnetic materials. In the first step of the development, we construct Helmholtz and Gibbs energy relations at the mesoscopic or lattice level based on the assumption that magnetic moments or spins are restricted to two orientations. Direct minimization of the Gibbs energy yields local average magnetization relations appropriate for operating regimes in which relaxation mechanisms are negligible whereas the balance of the Gibbs and relative thermal energies through Boltzmann principles provides local models which incorporate mechanisms such as thermal after-effects. To construct macroscopic relations that incorporate material nonhomogeneities, polycrystallinity, and variable effective fields, we employ stochastic homogenization techniques based on the assumption that parameters such as local coercive and interaction fields are manifestations of underlying distributions. The resulting framework quantifies in a natural manner the anhysteretic magnetization provided by decaying ac fields and guarantees the closure of biased minor loops once transient accommodation and after-effects are complete. Furthermore, noncongruency at differing magnetization levels is achieved with certain choices for the energy functionals. Hence, the framework provides an energy basis for certain extended Preisach models and the relation of the framework to several macroscopic hysteresis models is detailed. The behavior of both the nonlinear anhysteretic relations and full hysteresis model are validated through comparison with steel and nickel data. DA - 2006/7// PY - 2006/7// DO - 10.1109/TMAG.2006.875717 VL - 42 IS - 7 SP - 1747-1769 SN - 1941-0069 KW - actuators KW - Boltzmann equation KW - magnetic hysteresis KW - modeling KW - nonlinear magnetics ER - TY - JOUR TI - Fast solvers for 3D Poisson equations involving interfaces in a finite or the infinite domain AU - Lai, MC AU - Li, ZL AU - Lin, XB T2 - JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS AB - In this paper, numerical methods are proposed for Poisson equations defined in a finite or infinite domain in three dimensions. In the domain, there can exists an interface across which the source term, the flux, and therefore the solution may be discontinuous. The existence and uniqueness of the solution are also discussed. To deal with the discontinuity in the source term and in the flux, the original problem is transformed to a new one with a smooth solution. Such a transformation can be carried out easily through an extension of the jumps along the normal direction if the interface is expressed as the zero level set of a three-dimensional function. An auxiliary sphere is used to separate the infinite region into an interior and exterior domain. The Kelvin's inversion is used to map the exterior domain into an interior domain. The two Poisson equations defined in the interior and the exterior written in spherical coordinates are solved simultaneously. By choosing the mesh size carefully and exploiting the fast Fourier transform, the resulting finite difference equations can be solved efficiently. The approach in dealing with the interface has also been used with the artificial boundary condition technique which truncates the infinite domain. Numerical results demonstrate second order accuracy of our algorithms. DA - 2006/6/15/ PY - 2006/6/15/ DO - 10.1016/j.cam.2005.04.025 VL - 191 IS - 1 SP - 106-125 SN - 1879-1778 KW - arbitrary interface KW - fast 3D Poisson solver KW - immersed interface method KW - infinite domain KW - extension of jumps KW - spherical coordinates KW - level set function KW - artificial boundary condition ER - TY - JOUR TI - Auxiliary signal design for active failure detection in uncertain linear systems with a priori information AU - Nikoukhah, R AU - Campbell, SL T2 - AUTOMATICA AB - A method for auxiliary signal design for active failure detection based on a multi-model formulation of normal and failed systems is developed which allows for a priori information about initial conditions and the possibility of having a known input in addition to the test signal. These results permit the consideration of additional types of failures, such as biases, that a previous approach could not handle. Both theoretical results and computational algorithms are developed. DA - 2006/2// PY - 2006/2// DO - 10.1016/j.automatica.2005.09.011 VL - 42 IS - 2 SP - 219-228 SN - 1873-2836 KW - failure detection KW - active detection KW - test signal construction KW - model-based fault detection ER - TY - JOUR TI - Validation of two major quantitative trait loci for fusarium head blight resistance in Chinese wheat line W14 AU - Chen, J AU - Griffey, CA AU - Maroof, MAS AU - Stromberg, EL AU - Biyashev, RM AU - Zhao, W AU - Chappell, MR AU - Pridgen, TH AU - Dong, Y AU - Zeng, Z T2 - PLANT BREEDING AB - Abstract Identity of quantitative trait loci (QTL) governing resistance to fusarium head blight (FHB) initial infection (type I), spread (type II), kernel infection, and deoxynivalenol (DON) accumulation was characterized in Chinese wheat line W14. Ninety‐six double‐haploid lines derived from a cross of W14 × ’Pion2684’ were evaluated for FHB resistance in two greenhouse and one field experiment. Two known major QTL were validated on chromosomes 3BS and 5AS in W14 using the composite interval mapping method. The 3BS QTL had a larger effect on resistance than the 5AS QTL in the greenhouse experiments, whereas, the 5AS QTL had a larger effect in the field experiment. These two QTL together explained 33%, 35%, and 31% of the total phenotypic variation for disease spread, kernel infection, and DON concentration in the greenhouse experiments, respectively. In the field experiment, the two QTL explained 34% and 26% of the total phenotypic variation for FHB incidence and severity, respectively. W14 has both QTL, which confer reduced initial infection, disease spread, kernel infection, and DON accumulation. Therefore, marker‐assisted selection (MAS) for both QTL should be implemented in incorporating W14 resistance into adapted backgrounds. Flanking markers Xbarc 133 and Xgwm 493 on 3BS and Xbarc 117 and Xbarc 56 on 5AS are suggested for MAS. DA - 2006/2// PY - 2006/2// DO - 10.1111/j.1439-0523.2006.01182.x VL - 125 IS - 1 SP - 99-101 SN - 1439-0523 KW - Triticum aestivum KW - Fusarium head blight KW - microsatellite KW - QTL mapping ER - TY - JOUR TI - Sequencing precedence-related jobs on two machines to minimize the weighted completion time AU - Ramachandra, G AU - Elmaghraby, SE T2 - INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS AB - We address the problem P2|prec|∑wjCj. The problem is known to be NP-hard. We offer a binary integer program (BIP) and a dynamic program (DP); the latter is based on the concept of “initial subsets” of jobs and the optic of “weighted earliness–tardiness”. Although the DP approach expands the size of problems that can be solved to optimality to almost twice that obtained by the BIP, it reaches its computational limit around 25 jobs with mean job processing time of 10. We then introduce a genetic algorithm (GA) procedure that is capable of solving any problem size, and further extends the domain of applicability to more than two machines in parallel (problem Pm|prec|∑wjCj). The BIP is used also to establish a good lower bound against which the performance of the GA procedure is measured for larger size problems. Experimental investigation of the GA procedure demonstrates that it is capable of achieving the optimum in very few iterations (less than 20), thanks to the manner in which the initial population is generated, and that early abortion still yields excellent approximation to the optimum as judged by its proximity to the lower bound. DA - 2006/3// PY - 2006/3// DO - 10.1016/j.ijpe.2004.10.014 VL - 100 IS - 1 SP - 44-58 SN - 1873-7579 KW - scheduling KW - parallel machines KW - dynamic programming KW - genetic algorithm ER - TY - JOUR TI - Real-time identification of the draft system using neural network AU - Chun, SY AU - Bae, HJ AU - Kim, SM AU - Suh, MW AU - Grady, P AU - Lyoo, WS AU - Yoon, WS AU - Han, SS T2 - FIBERS AND POLYMERS DA - 2006/3// PY - 2006/3// DO - 10.1007/BF02933604 VL - 7 IS - 1 SP - 62-65 SN - 1875-0052 KW - draft system KW - sliver KW - control KW - neural network KW - modeling ER - TY - JOUR TI - Classification of Escherichia coli K-12 ribosome binding sites AU - May, EE AU - Vouk, MA AU - Bitzer, DL T2 - IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE AB - Drawing on parallels between genetic information processing in living organisms and the processing of communications data, we develop an error-control coding-based translation initiation classification system that uses an eleven base classification window. An overview of channel codes and a summary of the translation initiation process are presented. Parallels between the two are drawn and a brief review of a channel code model for translation initiation is shown. A block-code Bayesian classifier is presented and the results of applying the system to the translation start site location problem for Escherichia coli K-12 is discussed. DA - 2006/// PY - 2006/// DO - 10.1109/memb.2006.1578668 VL - 25 IS - 1 SP - 90-97 SN - 0739-5175 ER - TY - JOUR TI - An automated multiresolution procedure for modeling complex arrival processes AU - Kuhl, ME AU - Sumant, SG AU - Wilson, , JR T2 - INFORMS JOURNAL ON COMPUTING AB - To automate the multiresolution procedure of Kuhl et al. for modeling and simulating arrival processes that may exhibit a long-term trend, nested periodic phenomena (such as daily and weekly cycles), or both types of effects, we formulate a statistical-estimation method that involves the following steps at each resolution level corresponding to a basic cycle: (a) transforming the cumulative relative frequency of arrivals within the cycle (for example, the percentage of all arrivals as a function of the time of day within the daily cycle) to obtain a statistical model with approximately normal, constant-variance responses; (b) fitting a specially formulated polynomial to the transformed responses; (c) performing a likelihood ratio test to determine the degree of the fitted polynomial; and (d) fitting to the original (untransformed) responses a polynomial of the same form as in (b) with the degree determined in (c). A comprehensive experimental performance evaluation involving 100 independent replications of eight selected test processes demonstrates the accuracy and flexibility of the automated multiresolution procedure. DA - 2006/// PY - 2006/// DO - 10.1287/ijoc.1040.0113 VL - 18 IS - 1 SP - 3-18 SN - 1526-5528 KW - simulation KW - probability KW - stochastic model applications KW - statistics KW - estimation KW - statistical analysis KW - nonhomogeneous Poisson processes KW - time-dependent arrivals ER - TY - JOUR TI - A level-set method for interfacial flows with surfactant AU - Xu, JJ AU - Li, ZL AU - Lowengrub, J AU - Zhao, HK T2 - JOURNAL OF COMPUTATIONAL PHYSICS AB - A level-set method for the simulation of fluid interfaces with insoluble surfactant is presented in two-dimensions. The method can be straightforwardly extended to three-dimensions and to soluble surfactants. The method couples a semi-implicit discretization for solving the surfactant transport equation recently developed by Xu and Zhao [J. Xu, H. Zhao. An Eulerian formulation for solving partial differential equations along a moving interface, J. Sci. Comput. 19 (2003) 573–594] with the immersed interface method originally developed by LeVeque and Li and [R. LeVeque, Z. Li. The immersed interface method for elliptic equations with discontinuous coefficients and singular sources, SIAM J. Numer. Anal. 31 (1994) 1019–1044] for solving the fluid flow equations and the Laplace–Young boundary conditions across the interfaces. Novel techniques are developed to accurately conserve component mass and surfactant mass during the evolution. Convergence of the method is demonstrated numerically. The method is applied to study the effects of surfactant on single drops, drop–drop interactions and interactions among multiple drops in Stokes flow under a steady applied shear. Due to Marangoni forces and to non-uniform Capillary forces, the presence of surfactant results in larger drop deformations and more complex drop–drop interactions compared to the analogous cases for clean drops. The effects of surfactant are found to be most significant in flows with multiple drops. To our knowledge, this is the first time that the level-set method has been used to simulate fluid interfaces with surfactant. DA - 2006/3/1/ PY - 2006/3/1/ DO - 10.1016/j.jcp.2005.07.016 VL - 212 IS - 2 SP - 590-616 SN - 1090-2716 KW - incompressible stokes flow KW - interfaces KW - insoluble surfactant KW - Marangoni force KW - capillary force KW - level set method KW - immersed interface method ER - TY - JOUR TI - Variational approach to shape derivatives for a class of Bernoulli problems AU - Ito, K AU - Kunisch, K AU - Peichl, GH T2 - JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS AB - The shape derivative of a functional related to a Bernoulli problem is derived without using the shape derivative of the state. The gradient information is combined with level set ideas in a steepest descent algorithm. Numerical examples show the feasibility of the approach. DA - 2006/2/1/ PY - 2006/2/1/ DO - 10.1016/j.jmaa.2005.03.100 VL - 314 IS - 1 SP - 126-149 SN - 1096-0813 KW - shape derivative KW - Bernoulli problem KW - level set ER - TY - JOUR TI - Traffic grooming in WDM ring networks to minimize the maximum electronic port cost. AU - Chen, B. AU - Rouskas, G. AU - Dutta, R. T2 - Optical Switching and Networking DA - 2006/// PY - 2006/// VL - 2 IS - 1 SP - 1-18 ER - TY - JOUR TI - Scheduling of a two-machine flowshop with availability constraints on the first machine AU - Allaoui, H AU - Artiba, A AU - Elmaghraby, SE AU - Riane, F T2 - INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS AB - We treat the problem of scheduling n immediately available jobs in a flowshop composed of two machines in series with the objective of minimizing the makespan, when it is known that there shall be an interruption in machine availability on the first machine. We also consider two types of processing regimes: “stop resume” and “stop restart”. We present efficient dynamic program models for both regimes. But we focus on the performance of the Johnson rule as a heuristic. We establish the conditions under which it yields the optimum, and demonstrate that in other cases its performance is bounded by 2. DA - 2006/// PY - 2006/// DO - 10.1016/j.ijpe.2004.12.003 VL - 99 IS - 1-2 SP - 16-27 SN - 1873-7579 KW - scheduling KW - availability constraints KW - flowshop ER - TY - JOUR TI - Physiologically-based pharmacokinetic modeling of benzene in humans: A Bayesian approach AU - Yokley, Karen AU - Tran, Hien T. AU - Pekari, Kaija AU - Rappaport, Stephen AU - Riihimaki, Vesa AU - Rothman, Nat AU - Waidyanatha, Suramya AU - Schlosser, Paul M. T2 - RISK ANALYSIS AB - Benzene is myelotoxic and leukemogenic in humans exposed at high doses (>1 ppm, more definitely above 10 ppm) for extended periods. However, leukemia risks at lower exposures are uncertain. Benzene occurs widely in the work environment and also indoor air, but mostly below 1 ppm, so assessing the leukemia risks at these low concentrations is important. Here, we describe a human physiologically‐based pharmacokinetic (PBPK) model that quantifies tissue doses of benzene and its key metabolites, benzene oxide, phenol, and hydroquinone after inhalation and oral exposures. The model was integrated into a statistical framework that acknowledges sources of variation due to inherent intra‐ and interindividual variation, measurement error, and other data collection issues. A primary contribution of this work is the estimation of population distributions of key PBPK model parameters. We hypothesized that observed interindividual variability in the dosimetry of benzene and its metabolites resulted primarily from known or estimated variability in key metabolic parameters and that a statistical PBPK model that explicitly included variability in only those metabolic parameters would sufficiently describe the observed variability. We then identified parameter distributions for the PBPK model to characterize observed variability through the use of Markov chain Monte Carlo analysis applied to two data sets. The identified parameter distributions described most of the observed variability, but variability in physiological parameters such as organ weights may also be helpful to faithfully predict the observed human‐population variability in benzene dosimetry. DA - 2006/8// PY - 2006/8// DO - 10.1111/j.1539-6924.2006.00789.x VL - 26 IS - 4 SP - 925-943 SN - 0272-4332 KW - Bayesian KW - benzene KW - dosimetry KW - human KW - metabolism KW - PBPK KW - variability ER - TY - JOUR TI - Monte Carlo simulation of a solvated ionic polymer with cluster morphology AU - Matthews, JL AU - Lada, EK AU - Weiland, LM AU - Smith, RC AU - Leo, DJ T2 - SMART MATERIALS & STRUCTURES AB - A multiscale modeling approach for the prediction of material stiffness of the ionic polymer Nafion is presented. Traditional rotational isomeric state theory is applied in combination with a Monte Carlo methodology to develop a simulation model of the conformation of Nafion polymer chains on a nanoscopic level from which a large number of end-to-end chain lengths are generated. The probability density function of end-to-end distances is then estimated and used as an input parameter to enhance existing energetics-based macroscale models of ionic polymer behavior. Several methods for estimating the probability density function are compared, including estimation using Johnson distributions, Bézier distributions, and cubic splines. DA - 2006/2// PY - 2006/2// DO - 10.1088/0964-1726/15/1/048 VL - 15 IS - 1 SP - 187-199 SN - 0964-1726 ER - TY - JOUR TI - A unified framework for modeling hysteresis in ferroic materials AU - Smith, RC AU - Seelecke, S AU - Dapino, M AU - Ounaies, Z T2 - JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS AB - This paper addresses the development of a unified framework for quantifying hysteresis and constitutive nonlinearities inherent to ferroelectric, ferromagnetic and ferroelastic materials. Because the mechanisms which produce hysteresis vary substantially at the microscopic level, it is more natural to initiate model development at the mesoscopic, or lattice, level where the materials share common energy properties along with analogous domain structures. In the first step of the model development, Helmholtz and Gibbs energy relations are combined with Boltzmann theory to construct mesoscopic models which quantify the local average polarization, magnetization and strains in ferroelectric, ferromagnetic and ferroelastic materials. In the second step of the development, stochastic homogenization techniques are invoked to construct unified macroscopic models for nonhomogeneous, polycrystalline compounds exhibiting nonuniform effective fields. The combination of energy analysis and homogenization techniques produces low-order models in which a number of parameters can be correlated with physical attributes of measured data. Furthermore, the development of a unified modeling framework applicable to a broad range of ferroic compounds facilitates material characterization, transducer development, and model-based control design. Attributes of the models are illustrated through comparison with piezoceramic, magnetostrictive and shape memory alloy data and prediction of material behavior. DA - 2006/1// PY - 2006/1// DO - 10.1016/j.jmps.2005.08.006 VL - 54 IS - 1 SP - 46-85 SN - 1873-4782 KW - ferroic materials KW - unified models KW - hysteresis KW - constitutive nonlinearities ER - TY - JOUR TI - A simulation study of IP-based vertical handoff in wireless convergent networks AU - Song, Lung Kee AU - Wang, Wenye T2 - WIRELESS COMMUNICATIONS & MOBILE COMPUTING AB - Abstract The advances in wireless networks and IP technologies has brought ubiquitous access to all‐IP information into reality. For wireless IP services, IP‐based handoff is a critical issue to the performance of application‐level services. Although mobile IP (MIP) and its extensions, as network layer solutions, have been proposed as de facto standard, transmission throughput degradation due to packet loss, registration delay, and transport layer blocking are unavoidable because of MIP handoff mechanisms. In this paper, we evaluate the performance of a transport layer handoff approach, mobile stream control transmission protocol (mSCTP), and compare it with that of a network layer solution, MIP. mSCTP is based on stream control transmission protocol (SCTP), which is the third general purpose transport layer protocol from IETF. We investigate the use of mSCTP for seamless vertical handoff without any change in IP protocol stack by its multi‐homing feature and dynamic address reconfiguration (DAR) extension. We evaluate the performance of mSCTP and MIP by introducing handoff delay, end‐to‐end transmission throughput, and packet loss, and verify our observations by a simulation study of the two protocols in UMTS/802.11b integrated networks using NS‐2 network simulator. Copyright © 2006 John Wiley & Sons, Ltd. DA - 2006/8// PY - 2006/8// DO - 10.1002/wcm.415 VL - 6 IS - 5 SP - 629-650 SN - 1530-8677 KW - handoff KW - heterogeneous wireless networks KW - mobile IP KW - UMTS/WLANs ER - TY - JOUR TI - A performance study of an optical burst switched network with dynamic simultaneous link possession AU - Battestilli, T AU - Perros, H T2 - COMPUTER NETWORKS AB - In optical burst switched (OBS) networks a burst may occupy a wavelength on one or more links as it travels through the network. In the literature, OBS networks have been analyzed assuming that each burst occupies only a wavelength on a single link. In this paper, we study analytically the performance of an OBS network with a mixture of different size bursts. The short bursts occupy a wavelength on a single link while the long bursts occupy simultaneously wavelengths on multiple consecutive links. We develop a queueing network, which models simultaneous link possession, and we calculate analytically the end-to-end burst loss probabilities over a path in the OBS network. Our results indicate that having a mix of various size bursts can greatly effect the burst loss probabilities in the network. DA - 2006/2/8/ PY - 2006/2/8/ DO - 10.1016/j.comnet.2005.05.021 VL - 50 IS - 2 SP - 219-236 SN - 1872-7069 KW - optical burst switching (OBS) KW - optical networks KW - queueing network KW - simultaneous resource possession KW - burst loss probability KW - decomposition algorithm KW - traffic model ER - TY - JOUR TI - Interface conditions for Stokes equations with a discontinuous viscosity and surface sources AU - Ito, K AU - Li, ZL T2 - APPLIED MATHEMATICS LETTERS AB - The interface conditions, or jump conditions, for the pressure and the velocity of the solution to the incompressible Stokes equations with a discontinuous viscosity and a singular source along an interface are derived in this work. While parts of the results agree with those in the literature, some of the results are new. These theoretical results are useful for developing accurate numerical methods for the interface problem. DA - 2006/3// PY - 2006/3// DO - 10.1016/j.aml.2005.02.041 VL - 19 IS - 3 SP - 229-234 SN - 0893-9659 KW - incompressible Stokes equations KW - interface KW - discontinuous viscosity KW - interface conditions KW - singular sources ER - TY - CHAP TI - Finding equivalent rewritings in the presence of arithmetic comparisons AU - Afrati, F. AU - Chirkova, R. AU - Gergatsoulis, M. AU - Pavlaki, V. T2 - Advances in database technology : EDBT 2006 : 10th International Conference on Extending Database Technology, Munich, Germany, March 26-31, 2006: Proceedings (Lecture notes in computer science; 3896) AB - The problem of rewriting queries using views has received significant attention because of its applications in a wide variety of data-management problems. For select-project-join SQL (a.k.a. conjunctive) queries and views, there are efficient algorithms in the literature, which find equivalent and maximally contained rewritings. In the presence of arithmetic comparisons (ACs) the problem becomes more complex. We do not know how to find maximally contained rewritings in the general case. There are algorithms which find maximally contained rewritings only for special cases such as when ACs are restricted to be semi-interval. However, we know that the problem of finding an equivalent rewriting (if there exists one) in the presence of ACs is decidable, yet still doubly exponential. This complexity calls for an efficient algorithm which will perform better on average than the complete enumeration algorithm. In this work we present such an algorithm which is sound and complete. Its efficiency lies in that it considers fewer candidate rewritings because it includes a preliminary test to decide for each view whether it is potentially useful in some rewriting. PY - 2006/// DO - 10.1007/11687238_55 VL - 3896 SP - 942-960 PB - Berlin: Springer ER - TY - JOUR TI - Developing portfolios of water supply transfers AU - Characklis, GW AU - Kirsch, BR AU - Ramsey, J AU - Dillard, KEM AU - Kelley, CT T2 - WATER RESOURCES RESEARCH AB - Most cities rely on firm water supply capacity to meet demand, but increasing scarcity and supply costs are encouraging greater use of temporary transfers (e.g., spot leases, options). This raises questions regarding how best to coordinate the use of these transfers in meeting cost and reliability objectives. This paper combines a hydrologic–water market simulation with an optimization approach to identify portfolios of permanent rights, options, and leases that minimize the expected costs of meeting a city's annual demand with a specified reliability. Spot market prices are linked to hydrologic conditions and described by monthly lease price distributions which are used to price options via a risk‐neutral approach. Monthly choices regarding when and how much water to acquire through temporary transfers are made on the basis of anticipatory decision rules related to the ratio of expected supply to expected demand. The simulation is linked with an algorithm that uses an implicit filtering search method designed for solution surfaces that exhibit high‐frequency, low‐amplitude noise. This simulation‐optimization approach is applied to a region that currently supports an active water market, with results suggesting that temporary transfers can reduce expected water supply costs substantially, while still maintaining high reliability. Also evaluated are trade‐offs between expected costs and cost variability that occur with variation in a portfolio's distribution of rights, options, and leases. DA - 2006/5/3/ PY - 2006/5/3/ DO - 10.1029/2005wr004424 VL - 42 IS - 5 SP - SN - 1944-7973 ER - TY - JOUR TI - Dynamic bandwidth allocation by using efficient threshold reporting for quality of service in Ethernet passive optical networks AU - Yang, Y. M. AU - Nho, J. M. AU - Perros, H. AU - Mahalik, N. P. AU - Kim, K. AU - Ahn, B. H. T2 - Optical Engineering (Redondo Beach, Calif.) DA - 2006/// PY - 2006/// VL - 45 IS - 3 ER - TY - JOUR TI - Energy-efficient bandwidth allocation in wireless networks: Algorithms, analysis, and simulations AU - Wang, Wenye AU - Wang, Xinbing AU - Nilsson, Arne. A. T2 - IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS DA - 2006/5// PY - 2006/5// DO - 10.1109/TWC.2006.05018 VL - 5 IS - 5 SP - 1103-1114 SN - 1558-2248 KW - wireless networks KW - energy consumption KW - and connection admission control ER - TY - JOUR TI - Variation in volume production through clonal deployment: Results from a simulation model to minimize risk for both a currently known and unknown future pest AU - Yanchuk, A. D. AU - Bishir, J. AU - Russell, J. H. AU - Polsson, K. R. T2 - SILVAE GENETICA AB - Abstract A simulation model was developed to examine optimum patterns of deploying selected clones in the hypothetical situations of both a currently known pest and an unknown future pest. We modelled the interactions between Sitka spruce (Picea sitchensis (Bong.) Carr.), an economically important forest tree in British Columbia and the northwestern U.S., and the spruce terminal weevil (Pissodes strobi (Peck)), a major pest in western spruces. The model is combined with the Province of British Columbia’s Tree and Stand Simulator (TASS) model to drive individual tree growth and stand establishment and development. Two clonal-sampling strategies are examined: a randomly drawn set of genotypes or clones, to depict the potential consequences of a new (e.g., exotic) or a previously unimportant natural pest attacking a ‘random’ set of genotypes, and a ‘fixed’ set of clones, emulating a ‘commercial’ or known set of clones for growth and resistance mechanisms. Simulations use a range of numbers of genotypes or clones (2, 6, 18 and 30), and three deployment patterns (a random mixture of ramets, single- clone blocks, and a mosaic of smaller clonal blocks), in one and five hectare (Ha) stands. Total merchantable timber volume on a per Ha basis at harvest age 80 is used to compare the various combinations and schemes. With both random and fixed chosen sets of clones, the random planting pattern (i.e., random mixture of ramets from the clonal set) produced the most volume. Eighteen randomly chosen clones generally produced more volume, than 2, 6 and 30 clones, but differences among 6, 18 and 30 clones were small in most cases, irrespective of planting pattern. For fixed clones, the use of more resistant clones with higher growth potential produced more volume; however, pure clonal blocks of the best clone were not better than a mixture of that clone and an inferior one. Reducing the effects of insect activity and attack on trees, by lowering the average annual temperature in the model, or turning off all insect ‘activity’, increased merchantable volume but did not change the optimum number of clones (~18) or deployment pattern (random mixture). Forestry agencies can weigh these findings against economic advantages of block plantings of similar genotypes, in the choice of an appropriate number of clones and a deployment strategy. DA - 2006/// PY - 2006/// DO - 10.1515/sg-2006-0005 VL - 55 IS - 1 SP - 25-37 SN - 2509-8934 KW - clonal forestry KW - genetic diversity KW - risk KW - merchantable volume loss KW - insect resistance ER - TY - JOUR TI - Theoretical analysis of the SABUL congestion control algorithm AU - Oothongsap, P AU - Viniotis, Y AU - Vouk, M T2 - TELECOMMUNICATION SYSTEMS DA - 2006/3// PY - 2006/3// DO - 10.1007/s11235-006-6516-8 VL - 31 IS - 2-3 SP - 115-139 SN - 1572-9451 ER - TY - JOUR TI - Profit-oriented resource allocation using online scheduling in flexible heterogeneous networks AU - Xu, P AU - Michailidis, G AU - Devetsikiotis, M T2 - TELECOMMUNICATION SYSTEMS AB - In this paper, we discuss a generalized measurement-based adaptive scheduling framework for dynamic resource allocation in flexible heterogeneous networks, in order to ensure efficient service level performance under inherently variable traffic conditions. We formulate our generalized optimization model based on the notion of a “profit center” with an arbitrary number of service classes, nonlinear revenue and cost functions and general performance constraints. Subsequently, and under the assumption of a linear pricing model and average queue delay requirements, we develop a fast, low complexity algorithm for online dynamic resource allocation, and examine its properties. Finally, the proposed scheme is validated through an extensive simulation study. DA - 2006/3// PY - 2006/3// DO - 10.1007/s11235-006-6525-7 VL - 31 IS - 2-3 SP - 289-303 SN - 1572-9451 KW - resource allocation KW - on line scheduling KW - profit center ER - TY - JOUR TI - Performance analysis of limited-range wavelength conversion in an OBS switch AU - Puttasubbappa, VS AU - Perros, HG T2 - TELECOMMUNICATION SYSTEMS DA - 2006/3// PY - 2006/3// DO - 10.1007/s11235-006-6522-x VL - 31 IS - 2-3 SP - 227-246 SN - 1572-9451 KW - optical burst switching KW - limited-range wavelength conversion KW - performance evaluation KW - simultaneous resource allocation ER - TY - JOUR TI - Models and partition of variance for quantitative trait loci with epistasis and linkage disequilibrium AU - Wang, T. AU - Zeng, Z. B. T2 - BMC Genetics DA - 2006/// PY - 2006/// VL - 7 ER - TY - JOUR TI - Unit roots: Periodogram ordinate AU - Bhattacharyya, BB AU - Richardson, GD AU - Flores, PV T2 - STATISTICS & PROBABILITY LETTERS AB - The periodogram ordinate is used to define an asymptotic test for the testing problem H0:α=1 vs. HA:|α|<1 under appropriate assumptions on the model Yt=αYt-1+εt-θεt-1, where θ is near one. A drift term is also included in the model. An independent and identically distributed error structure as well as one exhibiting long memory are studied. DA - 2006/3/15/ PY - 2006/3/15/ DO - 10.1016/j.spl.2005.09.011 VL - 76 IS - 6 SP - 641-651 SN - 1879-2103 KW - autoregressive moving average processes KW - unit roots KW - periodograrn ordinate KW - limiting distributions ER - TY - JOUR TI - Determining sequence and ready times in a remanufacturing system AU - Stanfield, PM AU - King, RE AU - Hodgson, TJ T2 - IIE TRANSACTIONS AB - A fundamental scheduling problem is to determine a production start (ready) time for jobs based on customer-specified due dates. Typically, the objective is to delay the ready time in an attempt to minimize work-in-process inventory and maximize production system utilization. In many practical situations, notably remanufacturing operations, highly variable operation times and intricate process plans complicate this problem. In such a case, a specific ready time implies a confidence of on-time completion. Prior analytical results imply the optimal solution is a function of: (i) customer due dates; (ii) desired confidence levels; and (iii) stochastic makespan minimization. This paper proposes the use of a network flow model to represent a remanufacturing flowshop and then presents a structured heuristic approach that is able to develop sequences and ready times for remanufacturing systems by balancing the three factors. A broad experimental design is used to demonstrate that the proposed scheduling method outperforms previous list rules in terms of the calculated mean and robustness values. DA - 2006/7// PY - 2006/7// DO - 10.1080/07408170500371830 VL - 38 IS - 7 SP - 597-607 SN - 0740-817X ER - TY - JOUR TI - Communicating applied mathematics: Four examples AU - Finkel, Daniel E. AU - Kuster, Christopher AU - Lasater, Matthew AU - Levy, Rachel AU - Reese, Jill P. AU - Ipsen, Ilse C. F. T2 - SIAM REVIEW AB - Communicating Applied Mathematics is a writing- and speaking-intensive graduate course at North Carolina State University. The purpose of this article is to provide a brief description of the course objectives and the assignments. Parts A--D of of this article represent the class projects and illustrate the outcome of the course: We introduce a water-supply problem considered by the optimization and hydrology communities for benchmarking purposes. The objective is to drill five wells so that the cost of pumping water out of the ground is minimized. Using the implicit filtering optimization algorithm to locate the wells, we save approximately $2,500 over the cost of a given initial well configuration. The volume of powder poured into a bin with obstructions is found by calculating the height of the surface at every point. This is done using the fast marching algorithm. We look at two different bin geometries and determine the volumes as a function of the powder height under the spout. The surface of the powder satisfies a two-dimensional eikonal equation. This equation is solved using the fast marching method. Resonant tunneling diodes (RTDs) are ultrasmall semiconductor devices that have potential as very high-frequency oscillators. To describe the electron transport within these devices, physicists use the Wigner--Poisson equations which incorporate quantum mechanics to describe the distribution of electrons within the RTD. Continuation methods are employed to determine the steady-state electron distributions as a function of the voltage difference across the device. These simulations predict the operating state of the RTD under different applied voltages and will be a tool to help physicists understand how changing the voltage applied to the device leads to the development of current oscillations. When a thin film flows down an inclined plane, a bulge of fluid, known as a capillary ridge, forms on the leading edge and is subject to a fingering instability in which the fluid is channeled into rivulets. This process is familiar to us in everyday experiments such as painting a wall or pouring syrup over a stack of pancakes. It is also observed that changes in surface tension due to a temperature gradient can draw fluid up an inclined plane. Amazingly, in this situation the capillary ridge broadens and no fingering instability is observed. Numerical and analytical studies of a mathematical model of this process led to the discovery that these observations are associated with a nonclassical shock wave previously unknown to exist in thin liquid films. DA - 2006/6// PY - 2006/6// DO - 10.1137/S0036144504443523 VL - 48 IS - 2 SP - 359-389 SN - 1095-7200 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33744925177&partnerID=MN8TOARS KW - education KW - mathematical writing KW - presentations KW - audience KW - peer critique ER - TY - JOUR TI - Optical networks AU - Perros, H T2 - COMPUTER NETWORKS DA - 2006/2/8/ PY - 2006/2/8/ DO - 10.1016/j.comnet.2005.05.020 VL - 50 IS - 2 SP - 145-148 SN - 1872-7069 ER - TY - JOUR TI - Gain-scheduling control of LFT systems using parameter-dependent Lyapunov functions AU - Wu, F AU - Dong, K T2 - AUTOMATICA AB - In this paper, we propose a new control design approach for linear fractional transformation (LFT) systems using parameter-dependent Lyapunov functions. Instead of assuming parameter dependency in LFT fashion, we consider general parameter-dependent controllers to achieve better closed-loop performance. Using full-block multipliers, new LPV synthesis conditions have been derived in terms of finite number of linear matrix inequalities (LMIs). Both continuous- and discrete-time cases are discussed. A ship steering example has been used to demonstrate advantages and benefits of the proposed approach. DA - 2006/1// PY - 2006/1// DO - 10.1016/j.automatica.2005.08.020 VL - 42 IS - 1 SP - 39-50 SN - 1873-2836 KW - linear fractional transformation system KW - parameter-dependent Lyapunov function KW - full-block multiplier KW - L-2 gain KW - linear matrix inequality ER -