TY - BOOK TI - Next-Generation Internet Architectures and Protocols A3 - Ramamurthy, Byrav A3 - Rouskas, George N. A3 - Sivalingam, Krishna Moorthy AB - Book summary page views Book summary page views help Close Book summary page views help Book summary views reflect the number of visits to the book and chapter landing pages. Total views: 0 * Loading metrics... DA - 2009/// PY - 2009/// DO - 10.1017/cbo9780511920950 OP - PB - Cambridge University Press SN - 9780511920950 UR - http://dx.doi.org/10.1017/cbo9780511920950 DB - Crossref ER - TY - JOUR TI - Resource Co-Allocation for Large-Scale Distributed Environments AU - Castillo, Claris AU - Rouskas, George N. AU - Harfoush, Khaled AU - ACM T2 - Hpdc'09: 18th Acm International Symposium on High Performance Distributed Computing DA - 2009/// PY - 2009/// SP - 131-140 ER - TY - JOUR TI - Power Efficient Traffic Grooming in Optical WDM Networks AU - Yetginer, Emre AU - Rouskas, George N. AU - Ulema, M T2 - Globecom 2009 - 2009 Ieee Global Telecommunications Conference, Vols 1-8 DA - 2009/// PY - 2009/// SP - 1838-1843 ER - TY - JOUR TI - ERONs: Dynamic Lightpath Networking via Overlay Control of Static Optical Connections AU - Karmous-Edwards, Gigi AU - Vishwanath, Arun AU - Reeves, Douglas AU - Battestilli, Lina AU - Vegesna, Priyanka AU - Rouskas, George N. AU - IEEE T2 - Ondm: 2009 International Conference on Optical Network Design and Modeling DA - 2009/// PY - 2009/// SP - 1-6 ER - TY - JOUR TI - Considerations for Sizing Buffers in Optical Packet Switched Networks AU - Vishwanath, Arun AU - Sivaraman, Vijay AU - Rouskas, George N. AU - IEEE T2 - Ieee Infocom 2009 - Ieee Conference on Computer Communications, Vols 1-5 AB - Optical packet switches of the foreseeable future are expected to have severely limited buffering capability, since storage of optical signals remains a difficult and expensive operation. Our observations in simulation of TCP and real-time traffic in networks with such small buffers have revealed regions of anomalous performance in which losses for real-time traffic become higher as buffers get larger. The detrimental impact of larger optical buffers is studied in this paper and three new contributions are made. First, we develop a Markov chain model that allows analytical computation of loss. Our model validates observations from simulation, and opens the doors to an analytical understanding of how various factors affect the anomaly. Second, we study the anomaly under realistic traffic mixes containing persistent and non-persistent TCP flows, and show that the traffic mix does not significantly alter the anomaly. Third, we show that larger diversity in packet size between TCP and real-time traffic increases the severity of the anomaly, and is an important consideration when sizing optical switch buffers, particularly since real-time and TCP ACK packets are significantly smaller than the TCP data packets. Our study informs switch manufacturers and network operators of factors to consider when selecting optical buffer sizes in order to achieve desired performance balance between TCP and real-time traffic. DA - 2009/// PY - 2009/// DO - 10.1109/INFCOM.2009.5062047 SP - 1323-1331 ER - TY - JOUR TI - An Economic Model for Pricing Tiered Network Services AU - Lv, Qian AU - Rouskas, George N. AU - IEEE T2 - 2009 Ieee International Conference on Communications, Vols 1-8 DA - 2009/// PY - 2009/// SP - 1470-1475 ER - TY - JOUR TI - A Unified Architecture for Cross Layer Design in the Future Optical Internet AU - Baldine, I. AU - Dutta, R. AU - Rouskas, G. AU - IEEE T2 - 2009 35th European Conference on Optical Communication (Ecoc) DA - 2009/// PY - 2009/// ER - TY - CONF TI - Dual Prices in Multi-Product Production Planning Models with Congested Resources AU - Kefeli, A. AU - Uzsoy, R. AU - Fathi, Y. AU - Kay, M. T2 - INFORMS Computing Society Meeting C2 - 2009/1// CY - Charleston, SC DA - 2009/1// PY - 2009/1// ER - TY - CONF TI - Comparison of Iterative Simulation-Optimization Algorithms for Production Planning of a Semiconductor Manufacturing Line AU - Irdem, D.F. AU - Kacar, N.B. AU - Uzsoy, R. T2 - INFORMS Computing Society Meeting C2 - 2009/1// CY - Charleston, SC DA - 2009/1// PY - 2009/1// ER - TY - SOUND TI - Production Planning with Resources Subject to Congestion AU - Uzsoy, R. DA - 2009/2// PY - 2009/2// ER - TY - JOUR TI - Inventory control strategies in a recoverable system with state-dependent product returns AU - Ahıska, S.Ş. AU - King, R.E. T2 - Journal of Management and Engineering Integration DA - 2009/// PY - 2009/// VL - 2 IS - 1 SP - 1–8 ER - TY - JOUR TI - Bandwidth provisioning in ADSL access networks AU - Xiong, Kaiqi AU - Perros, Harry AU - Blake, Steven T2 - International Journal of Network Management AB - Abstract We consider an ADSL access network consisting of subscribers, digital subscriber line access multiplexers (DSLAMs), metro Ethernet switches and a broadband remote access aggregation server (BRAS). We obtain expressions for dimensioning the access network in the upstream direction. Specifically, we show that the bandwidth required at each DSLAM, metro Ethernet switch, and BRAS can be expressed as an exponential function of the subscribers in a log scale when the number of subscribers does not surpass a certain value. After this value, it grows linearly as a function of the subscribers. Copyright © 2009 John Wiley & Sons, Ltd. DA - 2009/9// PY - 2009/9// DO - 10.1002/nem.718 VL - 19 IS - 5 SP - 427-444 J2 - Int. J. Network Mgmt. LA - en OP - SN - 1055-7148 1099-1190 UR - http://dx.doi.org/10.1002/nem.718 DB - Crossref ER - TY - JOUR TI - Latticized Linear Optimization on the Unit Interval AU - Li, Pingke AU - Fang, Shu-Cherng T2 - IEEE Transactions on Fuzzy Systems AB - This paper considers the latticized linear optimization (LLO) problem and its variants, which are a special class of optimization problems constrained by fuzzy relational equations or inequalities. We show that an optimal solution to such a problem can be obtained in polynomial time as long as the objective function is a max-separable function with continuous monotone components. We further show that the set of all optimal solutions is fully determined by one maximum optimal solution and a finite number of minimal optimal solutions. The maximum optimal solution can be constructed in polynomial time once the optimal objective value is known, while the detection of all minimal optimal solutions in an efficient manner remains as a challenging problem. The relation between LLO and max-separable optimization and related issues are also investigated. DA - 2009/12// PY - 2009/12// DO - 10.1109/tfuzz.2009.2031561 VL - 17 IS - 6 SP - 1353-1365 J2 - IEEE Trans. Fuzzy Syst. OP - SN - 1063-6706 1941-0034 UR - http://dx.doi.org/10.1109/tfuzz.2009.2031561 DB - Crossref KW - Fuzzy optimization KW - fuzzy relational equations KW - max-separable optimization (MSO) ER - TY - JOUR TI - Measuring and partitioning the high-order linkage disequilibrium by multiple order Markov chains AU - Kim, Yunjung AU - Feng, Sheng AU - Zeng, Zhao-Bang T2 - Genetic Epidemiology AB - Genetic EpidemiologyVolume 33, Issue 2 p. 181-181 ErratumFree Access Measuring and partitioning the high-order linkage disequilibrium by multiple order Markov chains Yunjung Kim, Yunjung Kim Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina Department of Statistics, North Carolina State University, Raleigh, North Carolina Y. Kim and S. Feng contributed equally to this work.Search for more papers by this authorSheng Feng, Sheng Feng Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina Department of Statistics, North Carolina State University, Raleigh, North Carolina Y. Kim and S. Feng contributed equally to this work.Search for more papers by this authorZhao-Bang Zeng, Zhao-Bang Zeng Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina Department of Statistics, North Carolina State University, Raleigh, North Carolina Department of Genetics, North Carolina State University, Raleigh, North CarolinaSearch for more papers by this author Yunjung Kim, Yunjung Kim Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina Department of Statistics, North Carolina State University, Raleigh, North Carolina Y. Kim and S. Feng contributed equally to this work.Search for more papers by this authorSheng Feng, Sheng Feng Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina Department of Statistics, North Carolina State University, Raleigh, North Carolina Y. Kim and S. Feng contributed equally to this work.Search for more papers by this authorZhao-Bang Zeng, Zhao-Bang Zeng Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina Department of Statistics, North Carolina State University, Raleigh, North Carolina Department of Genetics, North Carolina State University, Raleigh, North CarolinaSearch for more papers by this author First published: 12 June 2008 https://doi.org/10.1002/gepi.20349 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume33, Issue2February 2009Pages 181-181 RelatedInformation DA - 2009/2// PY - 2009/2// DO - 10.1002/gepi.20349 VL - 33 IS - 2 SP - 181-181 J2 - Genet. Epidemiol. LA - en OP - SN - 0741-0395 1098-2272 UR - http://dx.doi.org/10.1002/gepi.20349 DB - Crossref ER - TY - JOUR TI - Active robust fault detection of closed-loop systems: general cost case AU - Ashari, A.E. AU - Nikoukhah, R. AU - Campbell, S.L. T2 - IFAC Proceedings Volumes AB - Active failure detection consists of finding an input signal (auxiliary signal) such that its use allows perfect detection of faults in a multi-model framework. In this paper we consider the problem of optimal auxiliary signal design for a linear uncertain system controlled by a linear feedback. The optimization criterion used is a worst case quadratic cost, which in practice is the same cost used for the design of the controller. Even though we suppose that the feedback controller is given, the methodology developed here should be useful for feedback design to achieve both control and fault detection objectives. DA - 2009/// PY - 2009/// DO - 10.3182/20090630-4-ES-2003.00097 VL - 42 IS - 8 SP - 585–590 UR - https://doi.org/10.3182/20090630-4-ES-2003.00097 ER - TY - CONF TI - Two applications of Modeling and Simulation in the Design and Development of Navy Systems AU - Drake, Kimberly J. AU - Bradshaw, Kristen AU - Violante, Patrick AU - Campbell, S.L. T2 - American Society of Naval Engineers (ASNE) Intelligent Ships Symposium VIII (ISSVIII) Proceedings C2 - 2009/5/12/ CY - Philadelphia, PA DA - 2009/5/12/ PY - 2009/5/12/ ER - TY - CONF TI - Robust Multi-Model Fault Detection and Control using an Active Closed-Loop Approach AU - Ashari, A.E. AU - Nikoukhah, R. AU - Campbell, S.L. T2 - 15th IFAC Symposium on System Identification - SYSID 2009 C2 - 2009/// C3 - Proceedings of the 15th IFAC Symposium on System Identification - SYSID 2009 CY - St. Malo, France DA - 2009/// PY - 2009/7/6/ ER - TY - JOUR TI - An organizational entrepreneurship model of supply management integration and performance outcomes AU - Handfield, R. AU - Petersen, K. AU - Cousins, P. AU - Lawson, B. T2 - International Journal of Operations and Production Management AB - Purpose The role of supply managers in driving corporate performance is changing, with an increased emphasis on supply market intelligence, collaboration, inter‐organizational partnerships, and operational integration with supply partners. These traits are also mirrored in the research on entrepreneurial settings and firms. The purpose of this paper is to explore the parallels between supply management roles, and the entrepreneurial skill sets and mechanisms that have been identified in prior research. Design/methodology/approach A structural equation model, using a sample of 151 manufacturing and service firms based in the UK, tests this hypothesised model. Findings The theoretical framework was supported, with results indicating that entrepreneurial behaviours (supply market intelligence and supply management influence) contribute to integration within the firm and with suppliers, in order to drive performance improvement. Practical implications The results provide support for purchasing managers seeking to improve performance by changing the recruitment and culture of the supply management function toward an entrepreneurial orientation. Originality/value Although the application of organizational entrepreneurship thinking to supply management theory is nascent, this paper's results suggest that further research along these lines may provide a resilient platform for utilisation of entrepreneurial constructs to explain supply management principles in buyer‐supplier collaboration, relational capital, and organisational outcomes. DA - 2009/// PY - 2009/// DO - 10.1108/01443570910932011 VL - 29 IS - 2 SP - 100-126 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-59349111646&partnerID=MN8TOARS KW - Entrepreneurialism KW - Supply chain management KW - Supplier relations ER - TY - CONF TI - Selecting Trustworthy Services: Learning a Bayesian Network AU - Hang, Chung-Wei AU - Singh, Munindar P. T2 - Seventh International Conference on Autonomous Agents & Multi-Agent Systems C2 - 2009/// C3 - Workshop on Trust in Agent Societies, Seventh International Conference on Autonomous Agents & Multi-Agent Systems CY - Budapest, Hungary DA - 2009/// PY - 2009/5/11/ PB - AAMAS ER - TY - JOUR TI - HIV Model Analysis and Estimation Implementation Under Optimal Control Based Treatment Strategies AU - David, J. AU - Tran, H. AU - Banks, H.T. T2 - International Journal of Pure and Applied Mathematics DA - 2009/// PY - 2009/// VL - 57 IS - 3 SP - 357–392 ER - TY - BOOK TI - Interface Problems and Methods in Biological and Physical Flows AU - Khoo, Boo Cheong AU - Li, Zhilin AU - Lin, Ping T2 - Lecture Notes Series (National University of Singapore, Institute for Mathematical Sciences) A3 - Khoo, Boo Cheong A3 - Li, Zhilin A3 - Lin, Ping AB - An Introduction to the Immersed Boundary and the Immersed Interface Methods Lecture Notes on Nonlinear Tumor Growth: Modeling and Simulation Progress in Modeling Pulsed Detonations Direct Numerical Simulations of Multiphase Flows. DA - 2009/5// PY - 2009/5// DO - 10.1142/7147 M1 - 17 PB - World Scientific SN - 9789812837844 9789812837851 UR - http://dx.doi.org/10.1142/7147 ER - TY - JOUR TI - Forecast updating and supplier coordination for complementary component purchases AU - Thomas, D.J. AU - Warsing, D.P. AU - Zhang, X. T2 - Production and Operations Management AB - We study a supply chain where an original equipment manufacturer (OEM) buys subassemblies, comprised of two complementary sets of components, from a contract manufacturer (CM). The OEM provides a demand forecast at the time when the CM must order the long lead‐time set of components, but must decide whether or not to provide updated forecasts as a matter of practice. Forecast updates affect the CM's short lead‐time purchase decision, and the anticipation of updates may also affect the long lead‐time purchase decision. While the OEM and CM both incur lost sales costs, the OEM can decide whether or not to share the overage costs otherwise fully borne by the CM. We investigate when the OEM is better served by committing to provide updated forecasts and/or committing to share overage costs. For a distribution‐free, two‐stage forecast‐update model, we show that (1) the practice of providing forecast updates may be harmful to the OEM and (2) at the OEM's optimal levels of overage risk sharing, the CM undersupplies relative to the supply chain optimal quantity. For a specific forecast‐update model, we computationally investigate conditions under which forecast updating and risk sharing are in the best interest of the OEM. DA - 2009/// PY - 2009/// DO - 10.1111/j.1937-5956.2009.01012.x VL - 18 IS - 2 SP - 167-184 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-67549088044&partnerID=MN8TOARS KW - supply contracts KW - forecast updating KW - production outsourcing ER - TY - JOUR TI - A survey on fuzzy relational equations, part I: classification and solvability AU - Li, Pingke AU - Fang, Shu-Cherng T2 - Fuzzy Optimization and Decision Making DA - 2009/3/28/ PY - 2009/3/28/ DO - 10.1007/S10700-009-9059-0 VL - 8 IS - 2 SP - 179-229 J2 - Fuzzy Optim Decis Making LA - en OP - SN - 1568-4539 1573-2908 UR - http://dx.doi.org/10.1007/S10700-009-9059-0 DB - Crossref KW - Fuzzy relational equation KW - Solvability KW - Duality KW - Adjointness KW - Triangular norm ER - TY - JOUR TI - An Experimental Study of the Performance Impact of Path-Based DoS Attacks in Wireless Mesh Networks AU - Agarwal, Avesh K. AU - Wang, Wenye T2 - Mobile Networks and Applications DA - 2009/8/28/ PY - 2009/8/28/ DO - 10.1007/s11036-009-0204-3 VL - 15 IS - 5 SP - 693-709 J2 - Mobile Netw Appl LA - en OP - SN - 1383-469X 1572-8153 UR - http://dx.doi.org/10.1007/s11036-009-0204-3 DB - Crossref KW - performance evaluation KW - wireless mesh KW - denial of service KW - implementation ER - TY - JOUR TI - Heuristics for capacity planning problems with congestion AU - Kim, Sukgon AU - Uzsoy, Reha T2 - Computers & Operations Research AB - Motivated by a problem in the semiconductor industry, we develop improved formulations for the problem of planning capacity acquisition and deletion over time when resources are subject to congestion, motivated by a problem in the semiconductor industry. We use nonlinear clearing functions to relate the expected output of a production resource in a planning period to the expected work in process (WIP) inventory level. Exploiting the properties of the clearing function allows us to formulate the single workcenter problem as a shortest path problem. This forms the basis for two greedy constructive heuristics and a Lagrangian heuristic for the multistage problem. The latter procedure also provides lower bounds on the optimal value. We present computational experiments showing that the proposed heuristics obtain high-quality solutions in modest CPU times. DA - 2009/6// PY - 2009/6// DO - 10.1016/j.cor.2008.06.006 VL - 36 IS - 6 SP - 1924-1934 J2 - Computers & Operations Research LA - en OP - SN - 0305-0548 UR - http://dx.doi.org/10.1016/j.cor.2008.06.006 DB - Crossref KW - Capacity expansion KW - Queueing KW - Clearing functions KW - Lagrangian relaxation KW - Heuristics ER - TY - JOUR TI - Production planning with resources subject to congestion AU - Asmundsson, Jakob AU - Rardin, Ronald L. AU - Turkseven, Can Hulusi AU - Uzsoy, Reha T2 - Naval Research Logistics AB - Abstract A fundamental difficulty in developing effective production planning models has been accurately reflecting the nonlinear dependency between workload and lead times. We develop a mathematical programming model for production planning in multiproduct, single stage systems that captures the nonlinear dependency between workload and lead times. We then use outer linearization of this nonlinear model to obtain a linear programming formulation and extend it to multistage systems. Extensive computational experiments validate the approach and compare its results to conventional models that assume workload‐independent planning lead times. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009 DA - 2009/3// PY - 2009/3// DO - 10.1002/nav.20335 VL - 56 IS - 2 SP - 142-157 J2 - Naval Research Logistics LA - en OP - SN - 0894-069X 1520-6750 UR - http://dx.doi.org/10.1002/nav.20335 DB - Crossref KW - production planning KW - clearing functions KW - mathematical programming KW - congestion ER - TY - CHAP TI - Approximate Rewriting of Queries Using Views AU - Afrati, Foto AU - Chandrachud, Manik AU - Chirkova, Rada AU - Mitra, Prasenjit T2 - Advances in Databases and Information Systems AB - We study approximate, that is contained and containing, rewritings of queries using views. We consider conjunctive queries with arithmetic comparisons (CQACs), which capture the full expressive power of SQL select-project-join queries. For contained rewritings, we present a sound and complete algorithm for constructing, for CQAC queries and views, a maximally-contained rewriting (MCR) whose all CQAC disjuncts have up to a predetermined number of view literals. For containing rewritings, we present a sound and efficient algorithm pruned-MiCR, which computes a CQAC containing rewriting that does not contain any other CQAC containing rewriting (i.e., computes a minimally containing rewriting, MiCR) and that has the minimum possible number of relational subgoals. As a result, the MiCR rewriting produced by our algorithm may be very efficient to execute. Both algorithms have good scalability and perform well in many practical cases, due to their extensive pruning of the search space, see [1]. PY - 2009/// DO - 10.1007/978-3-642-03973-7_13 SP - 164-178 OP - PB - Springer Berlin Heidelberg SN - 9783642039720 9783642039737 UR - http://dx.doi.org/10.1007/978-3-642-03973-7_13 DB - Crossref ER - TY - CONF TI - Characterizing Reactive Contaminant Sources in a Water Distribution System AU - Kumar, Jitendra AU - Brill, E. Downey AU - Mahinthakumar, G AU - Ranjithan, Ranji T2 - World Environmental and Water Resources Congress 2009 AB - Accurate knowledge of the characteristics of the contamination source during a contamination event is necessary for development of any mitigation and control strategy. Contaminant injected in a system is most likely to be reactive with chlorine; however, it is impractical for water quality monitoring systems to be able to monitor for the presence of all possible contaminants. In any distribution system, chlorine levels and other water quality parameters (pH, conductance, etc.) are routinely monitored to maintain the prescribed disinfection capacity. Any reactive contaminant would affect the chlorine levels resulting in deviations in the expected chlorine levels from those expected under normal operating conditions. Anomalies in the chlorine concentration from that of the expected value can be used as a surrogate to characterize the contaminant source in the system. In the absence of knowing the reactive characteristics of the contaminants, the location of injection, and injection pattern, source identification becomes a difficult problem to solve. Source identification can be posed as an inverse problem. In earlier work authors investigated the effect of the order of reaction kinetics of the contaminant with chlorine and its impact on source identification problem assuming the reaction kinetics to be known. That work is extended to investigate a methodology to address the source identification problem based on chlorine measurements, and the effects of different uncertain contamination conditions. Findings from a range of scenarios will be presented and discussed. C2 - 2009/5/12/ C3 - World Environmental and Water Resources Congress 2009 DA - 2009/5/12/ DO - 10.1061/41036(342)65 PB - American Society of Civil Engineers SN - 9780784410363 UR - http://dx.doi.org/10.1061/41036(342)65 DB - Crossref ER - TY - CONF TI - A Hybrid Heuristic Search Approach for Contaminant Source Characterization AU - Liu, Li AU - Brill, E. Downey AU - Mahinthakumar, G. (Kumar) AU - Ranjithan, S. Ranji T2 - World Environmental and Water Resources Congress 2009 AB - The rapid discovery of the contaminant source and its mass loading characteristics in a water distribution system (WDS) is vital for generating an efficient control strategy during a contamination event. Previous work on the Adaptive Dynamic Optimization Technique (ADOPT), which was developed as an Evolution Strategy (ES) based procedure, presents an approach to estimate the source characteristics adaptively, given dynamically updated observation data. Although this simulation-optimization approach is promising, it is computationally expensive, which poses challenges in the context of real-time solutions. This paper reports the findings of an investigation that builds upon the prior work by introducing a hybrid heuristic search method for the real-time characterization of a contaminant source. This new method integrates the ES-based ADOPT with a logistic regression (LR) analysis and a local improvement method to expedite the convergence and possibly solve the problem quickly. As a prescreening technique, a LR analysis step is performed prior to ADOPT; this step reduces the search space by eliminating unnecessary source nodes as potential source locations. Then, a local search (LS) approach is embedded into some of the algorithmic steps in ADOPT to serve as a postscreening step that potentially speeds up the convergence in localized regions in the solution space. Numerical experiments for the proposed hybrid approach are performed on an example water distribution network, and the results are compared with those of the standard implementation of ADOPT. C2 - 2009/5/12/ C3 - World Environmental and Water Resources Congress 2009 DA - 2009/5/12/ DO - 10.1061/41036(342)63 PB - American Society of Civil Engineers SN - 9780784410363 UR - http://dx.doi.org/10.1061/41036(342)63 DB - Crossref ER - TY - CHAP TI - Systematic Exploration of Efficient Query Plans for Automated Database Restructuring AU - Kormilitsin, Maxim AU - Chirkova, Rada AU - Fathi, Yahya AU - Stallmann, Matthias T2 - Advances in Databases and Information Systems AB - We consider the problem of selecting views and indexes that minimize the evaluation costs of the important queries under an upper bound on the disk space available for storing the views/indexes selected to be materialized. We propose a novel end-to-end approach that focuses on systematic exploration of plans for evaluating the queries. Specifically, we propose a framework (architecture) and algorithms that enable selection of views/indexes that contribute to the most efficient plans for the input queries, subject to the space bound. We present strong optimality guarantees on our architecture. Our algorithms search for sets of competitive plans for queries expressed in the language of conjunctive queries with arithmetic comparisons. This language captures the full expressive power of SQL select-project-join queries, which are common in practical database systems. Our experimental results demonstrate the competitiveness and scalability of our approach. PY - 2009/// DO - 10.1007/978-3-642-03973-7_11 SP - 133-148 OP - PB - Springer Berlin Heidelberg SN - 9783642039720 9783642039737 UR - http://dx.doi.org/10.1007/978-3-642-03973-7_11 DB - Crossref ER - TY - JOUR TI - Investigating the role of student motivation in computer science education through one-on-one tutoring AU - Boyer, Kristy Elizabeth AU - Phillips, Robert AU - Wallis, Michael D. AU - Vouk, Mladen A. AU - Lester, James C. T2 - Computer Science Education AB - The majority of computer science education research to date has focused on purely cognitive student outcomes. Understanding the motivational states experienced by students may enhance our understanding of the computer science learning process, and may reveal important instructional interventions that could benefit student engagement and retention. This article investigates issues of student motivation as they arise during one-on-one human tutoring in introductory computer science. The findings suggest that the choices made during instructional discourse are associated with cognitive and motivational outcomes, and that particular strategies can be leveraged based on an understanding of the student motivational state. DA - 2009/6// PY - 2009/6// DO - 10.1080/08993400902937584 VL - 19 IS - 2 SP - 111-135 J2 - Computer Science Education LA - en OP - SN - 0899-3408 1744-5175 UR - http://dx.doi.org/10.1080/08993400902937584 DB - Crossref KW - motivation KW - tutoring KW - confidence KW - CS1 KW - introductory programming KW - initiative ER - TY - CHAP TI - Tracking Files in the Kepler Provenance Framework AU - Mouallem, Pierre AU - Barreto, Roselyne AU - Klasky, Scott AU - Podhorszki, Norbert AU - Vouk, Mladen T2 - Lecture Notes in Computer Science PY - 2009/// DO - 10.1007/978-3-642-02279-1_21 SP - 273-282 OP - PB - Springer Berlin Heidelberg SN - 9783642022784 9783642022791 UR - http://dx.doi.org/10.1007/978-3-642-02279-1_21 DB - Crossref ER - TY - JOUR TI - Problems and techniques AU - Ipsen, I. T2 - SIAM Review DA - 2009/// PY - 2009/// VL - 51 IS - 1 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-59749092679&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - Evaluating and improving the performance of scientific software—this is the topic of the six-author paper “Optimization and Performance Modeling of Stencil Computations on Modern Multiprocessors.” Performance can degrade substantially when data are too large to fit in cache, so that data that do not fit in cache may have to be retrieved from main memory. Since memory traffic is slow compared to computation speed, processors become idle while waiting for data to arrive. The software in question is a code for the numerical solution by finite difference methods of the heat equation in three dimensions. The finite difference method is referred to as a “stencil computation” because each point in this three-dimensional grid requires information from a certain set of neighboring points (the stencil) to perform its computations. The code is evaluated on three different microprocessors: Itanium2, AMD Opteron, and IBM Power5; and also on the STI Cell processor. The authors evaluate strategies for managing memory hierarchies; and they examine issues such as cache blocking, cache-aware and cache-oblivious algorithms, local-store management, and hardware and software prefetching. The paper illustrates well the difficulty of this undertaking, and the interaction among the numerous hardware features and software strategies that affect the performance even of computations with simple and predictable memory access patterns. DA - 2009/2/5/ PY - 2009/2/5/ DO - 10.1137/siread000051000001000127000001 VL - 51 IS - 1 SP - 127-127 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-68649123647&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - This issue features two papers involving optimization problems, one targeted at minimizing temperature differences across a plate, and the other at multidimensional integration. 1. Want to turn the graphics card in your laptop or desktop into a personal supercomputer? Eddie Wadbro and Martin Berggren show you how, in their paper “Megapixel Topology Optimization on a Graphics Processing Unit.” The advantage of graphics cards is that they are cheap, relatively speaking, and that they allocate more resources to data processing than a CPU would. Graphics cards are also becoming easier to program (especially for those of us who grew up with Connection Machines and FPS-164s). Graphics processing units are natural hardware platforms for problems that are highly data parallel. This includes the topology optimization problem considered here, where a limited amount of high-conductivity material is to be distributed across a heated plate so that its temperature field is as even as possible. The authors express this as an area-to-point flow optimization problem. A subsequent finite element discretization gives a symmetric positive-definite linear system that is solved by a diagonally preconditioned conjugate gradient method. As it turns out, the optimal distribution of the high-conductivity material emanates like a root from the heat sink, with increasing girth and finer branches as the discretization is refined. 2. In their paper “Approximate Volume and Integration for Basic Semialgebraic Sets,” Didier Henrion, Jean Bernard Lasserre, and Carlo Savorgnan are concerned with deterministic techniques for difficult multidimensional integration, of the type where only brute force Monte Carlo methods have a chance at producing acceptable approximations. The bodies can be disconnected or nonconvex, and are described by sets of polynomial inequalities (i.e., semialgebraic sets). The foundation for this work was laid more than a hundred years ago, when Chebyshev, Markov, and Stieltjes showed how to approximate one-dimensional integrals by sequences of moments. In this paper, the authors formulate the multidimensional integration as an infinite-dimensional linear programming problem, and approximate the required moments by a hierarchy of semidefinite programming problems. Numerical examples illustrate that the approach produces accurate approximations in two and three dimensions. DA - 2009/11/4/ PY - 2009/11/4/ DO - 10.1137/siread000051000004000705000001 VL - 51 IS - 4 SP - 705-705 ER - TY - CONF TI - Modeling cerebral blood flow and regulation AU - Aoi, M. AU - Gremaud, P. AU - Tran, H.T. AU - Novak, V. AU - Olufsen, M.S. T2 - 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society AB - Cerebral autoregulation is a homeostatic mechanism which maintains blood flow despite changes in blood pressure in order to meet local metabolic demands. Several mechanisms play a role in cerebral autoregulation in order to adjust vascular tone and caliber of the cerebral vessels, but the exact etiology of the dynamics of these mechanism is not well understood. In this study, we discuss two patient specific models predicting cerebral blood flow velocity during postural change from sitting to standing. One model characterises cerebral autoregulation, the other describes the beat-to-beat distribution of blood flow to the major regions of the brain. Both models have been validated against experimental data from a healthy young subject. C2 - 2009/9// C3 - 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society DA - 2009/9// DO - 10.1109/IEMBS.2009.5334057 PB - IEEE UR - http://dx.doi.org/10.1109/IEMBS.2009.5334057 DB - Crossref ER - TY - JOUR TI - Active incipient fault detection with two simultaneous faults AU - Fair, Martene AU - Campbell, Stephen L. T2 - IFAC Proceedings Volumes AB - The problem of detecting small parameter variations in linear uncertain systems due to incipient faults, by injecting an input signal to enhance detection is considered. Unlike previous work where it is usually assumed that there is only one fault, in this paper we allow for two faults which is a natural assumption in the incipient case. A constructive method for the construction of an optimal input signal for achieving guaranteed detection with specified precision is presented in the discrete model case. The method is an extension of the multi-model approach used for the construction of auxiliary signals for failure detection, however, new technical issues must be addressed. DA - 2009/// PY - 2009/// DO - 10.3182/20090630-4-es-2003.00095 VL - 42 IS - 8 SP - 573-578 J2 - IFAC Proceedings Volumes LA - en OP - SN - 1474-6670 UR - http://dx.doi.org/10.3182/20090630-4-es-2003.00095 DB - Crossref ER - TY - CONF TI - Modeling Viscoelastic Wall Properties of Ovine Arteries AU - Valdez-Jasso, Daniela AU - Haider, Mansoor A. AU - Campbell, Stephen L. AU - Bia, Daniel AU - Zocalo, Yanina AU - Armentano, Ricardo L. AU - Olufsen, Mette S. T2 - ASME 2009 Summer Bioengineering Conference AB - Generation of a complete map of arterial wall mechanical properties can improve treatment of cardiovascular diseases via contributions to design of patient specific vascular substitutes used to alleviate atherosclerosis and stenoses, which are predominant in arterial pathways (i.e., abdominal aorta, carotids, or femoral arteries). Clinically useful estimation of arterial properties from patient data requires both efficient algorithms and models that are both complex enough to capture clinically important properties and simple enough to allow rapid computation. In this study, we used mechanical models accounting for both elastic and viscoelastic wall deformation to analyze how vessel properties and associated model parameters vary with artery type. It is known that for the aorta wall, deformation is dominated by nonlinear elastic dynamics, while for the smaller vessels (e.g. the carotid artery) deformation is dominated by viscoelastic responses. The latter is correlated with composition of the vessels; the aorta contains significantly less smooth muscle cells (∼40%) than the carotid artery (∼60%), and has significantly more elastin (see Fig 1). C2 - 2009/6/17/ C3 - ASME 2009 Summer Bioengineering Conference, Parts A and B DA - 2009/6/17/ DO - 10.1115/sbc2009-205640 PB - ASME SN - 9780791848913 UR - http://dx.doi.org/10.1115/sbc2009-205640 DB - Crossref ER - TY - JOUR TI - Feedback in Active Fault Detection AU - Ashari, Alireza Esna AU - Nikoukhah, Ramine AU - Campbell, Stephen L. T2 - IFAC Proceedings Volumes AB - In recent years there has been increased interest in the use of active approaches toward fault detection. In one of these approaches a test signal is designed such that over a short period it will reveal a fault not otherwise detectable and do so with as little perturbation of system performance as possible. Feedback plays an important role in control but its role in active fault detection based on test signals has not been explored. This paper begins that investigation. DA - 2009/// PY - 2009/// DO - 10.3182/20090706-3-fr-2004.00032 VL - 42 IS - 10 SP - 192-196 J2 - IFAC Proceedings Volumes LA - en OP - SN - 1474-6670 UR - http://dx.doi.org/10.3182/20090706-3-fr-2004.00032 DB - Crossref ER - TY - JOUR TI - Integrating Marine Observatories into a System-of-Systems: Messaging in the US Ocean Observatories Initiative T2 - OCEANS - ANCHORAGE DA - 2009/// PY - 2009/// UR - https://publons.com/publon/21294453/ ER - TY - CONF TI - Multiagent Commitment Alignment AU - Chopra, Amit K. AU - Singh, Munindar P. C2 - 2009/5// C3 - Proceedings of the 8th International Conference on Autonomous Agents and MultiAgent Systems (AAMAS) DA - 2009/5// VL - 1 SP - 937–944 PB - IFAAMAS UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84899835693&partnerID=MN8TOARS ER - TY - CONF TI - Koko: Engineering affective applications AU - Sollenberger, D.J. AU - Singh, M.P. C2 - 2009/// C3 - Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS DA - 2009/// VL - 2 SP - 1451-1452 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84899794043&partnerID=MN8TOARS ER - TY - CONF TI - Koko: Architecture and methodology for engineering social affective applications AU - Sollenberger, D.J. AU - Singh, M.P. C2 - 2009/// C3 - Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS DA - 2009/// VL - 2 SP - 1174-1175 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84899796109&partnerID=MN8TOARS ER - TY - CONF TI - Formal aspects of classifying and selecting business services AU - Udupi, Y.B. AU - Singh, M.P. C2 - 2009/// C3 - Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS DA - 2009/// VL - 2 SP - 1296-1297 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84899889033&partnerID=MN8TOARS ER - TY - CONF TI - Operators for Propagating Trust and their Evaluation in Social Networks AU - Hang, Chung-Wei AU - Wang, Yonghong AU - Singh, Munindar P. C2 - 2009/5// C3 - Proceedings of the 8th International Conference on Autonomous Agents and MultiAgent Systems (AAMAS) DA - 2009/5// VL - 2 SP - 1025–1032 PB - IFAAMAS UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84896062976&partnerID=MN8TOARS ER - TY - BOOK TI - Modelling interactions via commitments and expectations AU - Torroni, P. AU - Yolum, P. AU - Singh, M.P. AU - Alberti, M. AU - Chesani, F. AU - Gavanelli, M. AU - Lamma, E. AU - Mello, P. AB - Organizational models often rely on two assumptions: openness and heterogeneity. This is, for instance, the case with organizations consisting of individuals whose behaviour is unpredictable, whose internal structure is unknown, and who do not necessarily share common goals, desires, or intentions. This fact has motivated the adoption of social-based approaches to modelling interaction in organizational models. The idea of social semantics is to abstract away from the agent internals and provide a social meaning to agent message exchanges. In this chapter, we present and discuss two declarative, social semantic approaches for modelling interaction. The first one takes a state-oriented perspective, and models interaction in terms of commitments. The second one adopts a rule-oriented perspective, and models interaction in terms of logical formulae expressing expectations about agent interaction. We use a simple interaction protocol taken from the e-commerce domain to present the functioning and features of the commitment- and expectation-based approaches, and to discuss various forms of reasoning and verification that they accommodate, and how organizational modelling can benefit from them. DA - 2009/// PY - 2009/// DO - 10.4018/978-1-60566-256-5.ch011 SE - 263-284 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84901566756&partnerID=MN8TOARS ER - TY - CONF TI - Integrating marine observatories into a system-of-systems: Messaging in the US ocean observatories initiative AU - Arrott, M. AU - Chave, A.D. AU - Farcas, C. AU - Farcas, E. AU - Kleinert, J.E. AU - Krueger, I. AU - Meisinger, M. AU - Orcutt, J.A. AU - Peach, C. AU - Schofield, O. AU - Singh, M.P. AU - Vernon, F.L. C2 - 2009/// C3 - MTS/IEEE Biloxi - Marine Technology for Our Future: Global and Local Challenges, OCEANS 2009 DA - 2009/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-77951528644&partnerID=MN8TOARS ER - TY - BOOK TI - Enhancing tropos with commitments a business metamodel and methodology AU - Telang, P.R. AU - Singh, M.P. AB - This paper motivates a novel metamodel and methodology for specifying cross-organizational business interactions that is based on Tropos. Current approaches for business modeling are either high-level and semiformal or formal but low-level. Thus they fail to support flexible but rigorous modeling and enactment of business processes. This paper begins from the well-known Tropos approach and enhances it with commitments. It proposes a natural metamodel based on commitments and a methodology for specifying a business model. This paper includes an insurance industry case study that several researchers have previously used. DA - 2009/// PY - 2009/// DO - 10.1007/978-3-642-02463-4_22 VL - 5600 LNCS SE - 417-435 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-69049091007&partnerID=MN8TOARS ER - TY - JOUR TI - Enhancing Tropos with Commitments A Business Metamodel and Methodology T2 - Lecture Notes in Computer Science DA - 2009/// PY - 2009/// UR - https://publons.com/publon/21294448/ ER - TY - CONF TI - Choice, interoperability, and conformance in interaction protocols and service choreographies AU - Baldoni, M. AU - Desai, N. AU - Baroglio, C. AU - Patti, V. AU - Chopra, A.K. AU - Singh, M.P. C2 - 2009/// C3 - Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS DA - 2009/// VL - 1 SP - 608-615 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84899803605&partnerID=MN8TOARS ER - TY - BOOK TI - Architecture for affective social games AU - Sollenberger, D.J. AU - Singh, M.P. AB - The importance of affect in delivering engaging experiences in entertainment and education is well recognized. We introduce the Koko architecture, which describes a service-oriented middleware that reduces the burden of incorporating affect into games and other entertainment applications. Koko provides a representation for affect, thereby enabling developers to concentrate on the functional and creative aspects of their applications. The Koko architecture makes three key contributions: (1) improving developer productivity by creating a reusable and extensible environment; (2) yielding an enhanced user experience by enabling independently developed applications to collaborate and provide a more coherent user experience than currently possible; (3) enabling affective communication in multiplayer and social games. DA - 2009/// PY - 2009/// DO - 10.1007/978-3-642-11198-3_6 VL - 5920 LNAI SE - 79-94 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-72449207958&partnerID=MN8TOARS ER - TY - BOOK TI - Business modeling via commitments AU - Telang, P.R. AU - Singh, M.P. AB - Existing computer science approaches to business modeling offer low-level abstractions such as data and control flows, which fail to capture the business intent underlying the interactions that are central to real-life business models. In contrast, existing management science approaches are high-level but not only are these semiformal, they are also focused exclusively on managerial concerns such as valuations and profitability. This paper proposes a novel business metamodel based on commitments that considers additional agent-oriented concepts, specifically, goals and tasks. It proposes a set of business patterns and algorithms for checking model completeness and verification of agent interactions. Unlike traditional models, our approach marries rigor and flexibility, providing a crisp notion of correctness and compliance independent of specific executions. DA - 2009/// PY - 2009/// DO - 10.1007/978-3-642-10739-9_9 VL - 5907 LNCS SE - 111-125 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-71549122896&partnerID=MN8TOARS ER - TY - CONF TI - Systematic exploration of efficient query plans for automated database restructuring AU - Kormilitsin, Maxim AU - Chirkova, Rada AU - Fathi, Yahya AU - Stallmann, Matthias T2 - Springer, Berlin, Heidelberg C2 - 2009/// C3 - East European Conference on Advances in Databases and Information Systems DA - 2009/// SP - 133-148 ER - TY - JOUR TI - Computational design of asymmetric electron beam devices AU - Ives, R. L. AU - Attarian, A. AU - Bui, T. AU - Read, M. AU - David, J. AU - Tran, Hien AU - Tallis, W. J. AU - Davis, S. AU - Gadson, S. E. AU - Blach, N. AU - Brown, John AU - Kiley, E. T2 - IEEE Transactions on Electron Devices AB - Three-dimensional design codes are allowing the development of more complex electron beam devices with significant performance improvements over axially symmetric devices. Distributed beam RF devices, including multiple-beam and sheet-beam designs, allow significant reduction in operating voltage with improved efficiency and bandwidth. The increased parameter space, however, makes the design process extremely complicated and costly. This paper describes optimization techniques to automate the most time-consuming tasks of the design, which is searching the available parameter space to optimize performance. Both sheet-beam and multiple-beam designs are considered. DA - 2009/// PY - 2009/// DO - 10.1109/TED.2009.2015421 VL - 56 IS - 5 SP - 753–761 KW - Computer optimization KW - electron beam KW - electron gun KW - multiple beam KW - RF sources KW - sheet beam ER - TY - JOUR TI - Combining Trust-Region Techniques and {R}osenbrock Methods for Gradient Systems AU - Luo, X-L AU - Kelley, C T AU - Liao, L-Z. AU - Tam, H-W T2 - J. Optim. Theory Appl. DA - 2009/// PY - 2009/// VL - 140 SP - 265-286 ER - TY - CONF TI - Calibration of Ground Water Models with {POD} AU - Kelley, C T AU - Winton, C AU - Eslinger, O J AU - Pettway, J A2 - Heinkenschloss, M A2 - Hoppe, R H W A2 - Schultz, V C2 - 2009/// C3 - Numerical Techniques for Optimization Problems with PDE constraints DA - 2009/// SP - 47-49 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 - 2009/// PY - 2009/// VL - 31 IS - 1 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-73649094469&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - Halftoning and manifold learning are the two subjects of this issue. Halftoning will help you to understand better what goes on inside your printer, in particular how your printer converts continuous images to pixels. Manifold learning has the potential to become an important approach for machine learning, specifically for the automated analysis of large high-dimensional data sets. 1. Manifold learning is a form of dimension reduction, where one assumes that data lie on a low-dimensional manifold within a high-dimensional space. Applications of manifold learning include object recognition, computer vision, speech analysis, and molecular dynamics simulations. Hongyuan Zha and Zhenyue Zhang, the authors of the paper “Spectral Properties of the Alignment Matrices in Manifold Learning,” focus on a particular class of local manifold learning methods known as local tangent space alignment (LTSA). LTSA computes representations for local neighborhoods of a manifold, and then combines, or aligns, all the local representations into one global representation for the whole manifold. This involves the computation of eigenspaces and null spaces of alignment matrices. The accuracy of LTSA is affected by the amount of overlap among local neighborhoods, as well as by perturbations from noise and computational errors. Armed with tools from matrix and graph theory the authors determine the impact of overlap under ideal conditions, when computations are free of errors, and they determine the accuracy of the null spaces when the alignment matrices are subjected to perturbations. 2. Black ink printers convert grayscale images into images made up of binary pixels in such a way that the human eye perceives almost no difference between the binary and the grayscale image. This conversion process is called “halftoning.” It works because the human eye has the ability to perform spatial smoothing. In contrast, an artificial vision system with a sufficiently fine resolution perceives a binary halftone image as merely a chaotic mess of pixels. In his paper “Least-Squares Halftoning via Human Vision System and Markov Gradient Descent (LS-MGD): Algorithm and Analysis,” Jianhong (Jackie) Shen models the human vision system as a point spread function that is weakly lowpass and quantifies its spatial smoothing ability. He presents a halftoning algorithm based on a randomized gradient descent approach that minimizes the difference between the perceived binary and continuous images in the least squares sense. Numerical experiments with test images give a good feel for the performance of the algorithm. DA - 2009/8/6/ PY - 2009/8/6/ DO - 10.1137/siread000051000003000543000001 VL - 51 IS - 3 SP - 543-543 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-59749092679&partnerID=MN8TOARS ER - TY - JOUR TI - Problems and Techniques AU - Ipsen, Ilse T2 - SIAM Review AB - The two papers in this issue share a common concern: smoothing. In the first paper, it is time series that are being smoothed, and in the second paper it is multigrid methods that do the smoothing for PDE-constrained optimization problems. In biology, medicine, finance, economics, geophysics, and social sciences one frequently needs to discern “trends” in data sets. Mathematically, this problem is known as filtering, smoothing, or time series analysis, and many different methods have been devised, including moving average filters, bandpass filters, and smoothing splines. For a given set of scalars $y_t$, one wants to find another set of scalars $x_t$ that vary smoothly, but that are close to the original set. The new points $x_t$ are considered to represent the underlying trend. The question now is, how do we define what it means to “vary smoothly”? Seung-Jean Kim, Kwangmoo Koh, Stephen Boyd, and Dimitry Gorinevsky answer this question in the one-norm. In their paper “$\ell_1$ Trend Filtering,” they minimize an expression containing a one-norm, so that the resulting $x_t$ are points of a piecewise linear function. The minimization is formulated as a convex quadratic program and solved by an interior point method. This paper should be of interest to many readers, because of its connections to $\ell_1$ regularization in geophysics, signal processing, statistics, and sparse approximation. In their paper “Multigrid Methods for PDE Optimization,” Alfio Borzì and Volker Schulz review multigrid methods for solving infinite-dimensional optimization problems whose constraints are expressed in terms of partial differential equations (PDEs). Such optimization problem arise in optimal control, shape design, and shape optimization. Multigrid methods, very informally, solve PDEs by discretizing them iteratively on a hierarchy of grids, so as to capture all frequencies. So-called smoothers are responsible for high frequencies, while lower frequencies are resolved on coarser grids. This paper is essentially self-contained. It starts by introducing terminology for PDE-constrained optimization problems and reviewing multigrid methods. Subsequent discussions focus on multigrid SQP, Schur-complement-based multigrid smoothers, and collective smoothing multigrid, as well as applications to optimal control problems governed by hyperbolic, elliptic, and parabolic PDEs. DA - 2009/5// PY - 2009/5// DO - 10.1137/siread000051000002000337000001 VL - 51 IS - 2 SP - 337-337 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-68649123647&partnerID=MN8TOARS ER - TY - JOUR TI - Preface to the 14th ILAS Conference Proceedings Shanghai 2007 T2 - Linear Algebra and Its Applications DA - 2009/// PY - 2009/// DO - 10.1016/j.laa.2008.10.002 VL - 430 IS - 5-6 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-58349086314&partnerID=MN8TOARS ER - TY - JOUR TI - AUXILIARY SIGNAL DESIGN FOR FAULT DETECTION IN NONLINEAR SYSTEMS AU - Sweetingham, K.A. AU - Campbella, S.L. T2 - Control and Intelligent Systems AB - Recently, there has been considerable research on active fault detection and model identification algorithms for linear systems. These algorithms compute an auxiliary input signal which guarantees fault detection, assuming a bounded noise. This paper begins to address the issue of applying the previously developed linear theory to nonlinear systems. To exploit the known linear theory, linearizations are used and bounds are computed to find the allowable noise for the nonlinear system. We also present an example of an oscillating pendulum to verify the bounds computed. DA - 2009/// PY - 2009/// DO - 10.2316/journal.201.2009.3.201-2049 VL - 37 IS - 3 J2 - LA - en OP - SN - 1925-5810 UR - http://dx.doi.org/10.2316/journal.201.2009.3.201-2049 DB - Crossref ER - TY - CHAP TI - Numerical Techniques for Simulation, Parameter Estimation, and Noise Control in Structural Acoustic Systems AU - Banks, H. T. AU - Smith, R. C. T2 - Dynamics and Control of Distributed Systems A2 - Tzou, H. S. A2 - Bergman, L. A. AB - A model for a 3-D structural acoustic system, currently being used for parameter estimation and control experiments in the Acoustics Division, NASA Langley Research Center, is presented. This system consists of a hard-walled cylinder with a flexible circular plate at one end. An exterior noise source causes vibrations in the plate which in turn lead to unwanted noise inside the cylinder. Control is implemented through the excitation of piezoceramic patches bonded to the plate which generate in-plane forces and/or bending moments in response to an input voltage. PY - 2009/12/22/ DO - 10.1017/cbo9780511530180.006 SP - 202-263 OP - PB - Cambridge University Press SN - 9780511530180 UR - http://dx.doi.org/10.1017/cbo9780511530180.006 DB - Crossref ER - TY - RPRT TI - Raleigh Durham Airport Wildlife Hazard Assessment AU - Roise, J.P. AU - Browne, M. AU - Hertl, P. AU - Berner, A. A3 - Approved by FAA, study commissioned by RDU DA - 2009/// PY - 2009/// PB - Approved by FAA, study commissioned by RDU ER - TY - JOUR TI - Design for Six Sigma: Design and Development of an Equine Composite Flooring System AU - Wood, Jesse William DA - 2009/// PY - 2009/// ER - TY - CONF TI - Computing across curricula: The view of industry leaders AU - Wiebe, Eric AU - Ho, Chia-Lin AU - Raubenheimer, Dianne AU - Bullard, Lisa AU - Joines, Jeff AU - Miller, Carolyn AU - Rouskas, George T2 - American Society for Engineering Education C2 - 2009/// C3 - American Society for Engineering Education DA - 2009/// ER - TY - JOUR TI - Applying Linear Regression and Neural Network Meta-Models for Evolutionary Algorithm Based Simulation Optimization AU - Propst, Michael David DA - 2009/// PY - 2009/// ER - TY - CONF TI - AC 2009-676: COMPUTING ACROSS CURRICULA: THE VIEW OF INDUSTRY LEADERS AU - Wiebe, Eric AU - others C2 - 2009/// C3 - ASEE DA - 2009/// VL - 14 SP - 1 ER - TY - CONF TI - AC 2009-209: USING COMPUTATIONAL TOOLS TO ENHANCE PROBLEM SOLVING AU - Raubenheimer, Dianne AU - Joines, Jeff AU - Craig, Amy C2 - 2009/// C3 - ASEE DA - 2009/// VL - 14 SP - 1 ER - TY - BLOG TI - Simulation and Lean Six Sigma: Part 3 Defining Lean and Simulation, Success in Simulation AU - Joines, J.A. T2 - simio.biz DA - 2009/1/9/ PY - 2009/1/9/ UR - http://simio.biz/blog/2009/02/05/six-sigma-and-simulation-part-3/ ER - TY - CONF TI - Using Computational Tools to Enhance Problem Solving AU - Craig, A. AU - Joines, J.A. AU - Raubenheimer, D. T2 - American Society for Engineering Education International Conference C2 - 2009/// C3 - American Society for Engineering Education DA - 2009/// UR - http://soa.asee.org/paper/conference/paper-view.cfm?id=10163 ER - TY - JOUR TI - Integration of Computer Based Problem Solving Into Engineering Curricula AU - Brent, R. AU - Craig, A. AU - Joines, J. AU - Raubenheimer, D. T2 - Computers in Engineering Education Journal DA - 2009/// PY - 2009/// VL - 19 IS - Jan-March ER - TY - BOOK TI - Computer simulation techniques: the definitive introduction! AU - Perros, Harry G. DA - 2009/// PY - 2009/// PB - Raleigh, NC: Harry Perros. ER - TY - JOUR TI - SecureMR: A Service Integrity Assurance Framework for Map Reduce AU - Wei, Wei AU - Du, Juan AU - Yu, Ting AU - Gu, Xiaohui T2 - 25TH ANNUAL COMPUTER SECURITY APPLICATIONS CONFERENCE AB - MapReduce has become increasingly popular as a powerful parallel data processing model. To deploy MapReduce as a data processing service over open systems such as service oriented architecture, cloud computing, and volunteer computing, we must provide necessary security mechanisms to protect the integrity of MapReduce data processing services. In this paper, we present SecureMR, a practical service integrity assurance framework for MapReduce. SecureMR consists of five security components, which provide a set of practical security mechanisms that not only ensure MapReduce service integrity as well as to prevent replay and denial of service (DoS) attacks, but also preserve the simplicity, applicability and scalability of MapReduce. We have implemented a prototype of SecureMR based on Hadoop, an open source MapReduce implementation. Our analytical study and experimental results show that SecureMR can ensure data processing service integrity while imposing low performance overhead. DA - 2009/// PY - 2009/// DO - 10.1109/acsac.2009.17 SP - 73-82 ER - TY - JOUR TI - FIRST: Combining forward iterative selection and shrinkage in high dimensional sparse linear regression AU - Hwang, W. Y. AU - Zhang, H. H. AU - Ghosal, S. T2 - Statistics and its Interface AB - We propose a new class of variable selection techniques for regression in high dimensional linear models based on a forward selection version of the LASSO, adaptive LASSO or elastic net, respectively to be called as forward iterative regression and shrinkage technique (FIRST), adaptive FIRST and elastic FIRST. These methods seem to work effectively for extremely sparse high dimensional linear models. We exploit the fact that the LASSO, adaptive LASSO and elastic net have closed form solutions when the predictor is onedimensional. The explicit formula is then repeatedly used in an iterative fashion to build the model until convergence occurs. By carefully considering the relationship between estimators at successive stages, we develop fast algorithms to compute our estimators. The performance of our new estimators are compared with commonly used estimators in terms of predictive accuracy and errors in variable selection. AMS 2000 subject classifications: Primary 62J05, 62J05; secondary 62J07. DA - 2009/// PY - 2009/// DO - 10.4310/sii.2009.v2.n3.a7 VL - 2 IS - 3 SP - 341-348 ER - TY - CONF TI - Machine system for harvesting small diameter woody biomass and reducing hazardous fuels: A developmental report AU - Roise, Joseph AU - Hannum, L. C. AU - Catts, G. P. AB - This is a report on field testing and refinement of the first generation FECON Bio-Harvester, designed to swath harvest small diameter woody biomass of mixed species and size classes. The machine system consisted of a unique harvesting head, a FECON FTX440, a silage dump wagon and roll-on-roll-off bins. The cutting system consists of a rotating drum with cutting tools, followed by an auger and a material fan which blew the harvested biomass into the silage dump wagon. The harvesting head is PTO driven. The machine system was tests in natural forest understory, between rows of pine plantations and in a Pocosin ecosystem. The sites had 6 to 20 green tons per acre of small diameter woody biomass. Below are the resulting harvesting productivity and cost. C2 - 2009/// C3 - 2009 Bioenergy Engineering Conference DA - 2009/// DO - 10.13031/2013.28860 ER - TY - JOUR TI - elm Optimal resource allocation in stochastic activity networks via the electromagnetism approach: a platform implementation in Java AU - Tereso, A. P. AU - Novais, R. A. AU - Araujo, M. M. T. AU - Elmaghraby, S. E. T2 - Control and Cybernetics DA - 2009/// PY - 2009/// VL - 38 IS - 3 SP - 745-782 ER - TY - CONF TI - Architecture for affective social games AU - Sollenberger, D. J. AU - Singh, M. P. C2 - 2009/// C3 - Agents for games and simulations: trends in techniques, concepts and design DA - 2009/// VL - 5920 SP - 79-94 ER - TY - BOOK TI - Mathematical and experimental modeling of physical and biological processes AU - Banks, H. T. AU - Tran, H. T. DA - 2009/// PY - 2009/// PB - Boca Raton : CRC Press SN - 9781420073379 ER - TY - BOOK TI - Interface problems and methods in biological and physical flows A3 - B. C. Khoo, Z. Li A3 - Lin, P. DA - 2009/// PY - 2009/// PB - New Jersey: World Scientific SN - 9789812837844 ER - TY - BOOK TI - Advancing the Frontiers of Simulation: A festschrift in honor of George Samuel Fishman AU - Alexopoulos, C. AU - Goldsman, D. AU - Wilson, J. R. A3 - Alexopoulos, C. A3 - Goldsman, D. A3 - Wilson, J. R. DA - 2009/// PY - 2009/// PB - New York: Springer Verlag SN - 9781441908162 ER - TY - JOUR TI - Active incipient fault detection with more than two simultaneous faults AU - Fair, Martene AU - Campbell, Stephen L. T2 - 2009 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN AND CYBERNETICS (SMC 2009), VOLS 1-9 AB - The problem of detecting small parameter variations in linear uncertain systems due to incipient faults, with the possibility of injecting an input signal to enhance detection, is considered. Most studies assume that there is only one fault developing. Recently an active approach for two simultaneous faults has been introduced. In this paper we extend this approach to allow for more than two simultaneous faults. Having more than two simultaneous incipient faults is sometimes a natural assumption. A computational method for the construction of an input signal for achieving guaranteed detection with specified precision is presented for discrete time systems. The method is an extension of a multi-model approach used for the construction of auxiliary signals for failure detection, however, new technical issues must be addressed. A case study is examined. DA - 2009/// PY - 2009/// DO - 10.1109/icsmc.2009.5346202 SP - 3322-3327 SN - 1062-922X KW - Failure detection KW - linear system KW - detection systems KW - feedback KW - optimal detection ER - TY - BOOK TI - Generalized Inverses of Linear Transformations AU - Campbell, Stephen L. AU - Meyer, Carl D. AB - Preface to the Classics edition Preface Introduction and other preliminaries 1. The Moore-Penrose or generalized inverse 2. Least squares solutions 3. Sums, partitioned matrices and the constrained generalized inverse 4. Partial isometries and EP matrices 5. The generalized inverse in electrical engineering 6. (i, j, k)-Generalized inverses and linear estimation 7. The Drazin inverse 8. Applications of the Drazin inverse to the theory of finite Markov chains 9. Applications of the Drazin inverse 10. Continuity of the generalized inverse 11. Linear programming 12. Computational concerns Bibliography Index. DA - 2009/// PY - 2009/// DO - 10.1137/1.9780898719048 VL - 56 PB - Society for Industrial and Applied Mathematics SE - 1-272 SN - 978-0-898716-71-9 ER - TY - CONF TI - Business modeling via commitments AU - Telang, P. R. AU - Singh, M. P. C2 - 2009/// C3 - Service-oriented computing: agents, semantics, and engineering, proceedings DA - 2009/// VL - 5907 SP - 111-125 ER - TY - JOUR TI - FISTE: A Black Box Approach for End-to-End QoS Management AU - Feng, Benjamin Zhong Ming AU - Huang, Changcheng AU - Devetsikiotis, Michael T2 - ACM TRANSACTIONS ON MODELING AND COMPUTER SIMULATION AB - The goal of traffic engineering is to achieve a target Quality of Service (QoS) while maximizing network utilization. While determining the QoS for end-to-end paths in a network under self-similar traffic models is difficult, end-to-end network performance analysis is still essential in providing QoS to networks such as Virtual Private Networks (VPN) and Peer-to-Peer (P2P) networks. The Fast Importance Sampling based Traffic Engineering (FISTE) approach proposed in this article is a prediction-based approach that maps the ingress traffic levels of a network to the QoS of end-to-end path(s) in the network. Because FISTE is a hybrid of simulation analysis and closed-form analysis, it can treat a complex network as a black box. When we combined Simulated Annealing (SA) with FISTE, the resulting approach can provide a traffic engineering solution so that multiple end-to-end QoS requirements are satisfied while the network resource utilization is maximized. FISTE originated from the concept of Importance Sampling (IS), and our approach differs from the previous Importance Sampling based approaches since this is the first time that IS is applied to multi-queue systems under Fractional Gaussian Noise (FGN) input and traffic engineering. DA - 2009/10// PY - 2009/10// DO - 10.1145/1596519.1596521 VL - 19 IS - 4 SP - SN - 1558-1195 KW - Overlay network KW - importance Sampling KW - response surface KW - traffic engineering KW - self-similar KW - fractal gaussian noise KW - congestion KW - latency KW - packet loss KW - buffer overflow KW - Monte Carlo KW - end-to-end QoS KW - simulated annealing KW - peer-to-peer KW - virtual private network KW - prediction KW - heuristic search ER - TY - JOUR TI - Completions of nonlinear DAE flows based on index reduction techniques and their stabilization AU - Campbell, Stephen L. AU - Kunkel, Peter T2 - JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS AB - Differential algebraic equations (DAEs) define a differential equation on a manifold. A number of ways have been developed to numerically solve some classes of DAEs. Motivated by problems in control theory, numerical simulation, and the use of general purpose modeling environments, recent research has considered the embedding of the DAE solutions of a general DAE into the solutions of an ODE where the added dynamics have special properties. This paper both provides new results on the linear time-varying case and considers the important nonlinear case. DA - 2009/12/15/ PY - 2009/12/15/ DO - 10.1016/j.cam.2009.08.111 VL - 233 IS - 4 SP - 1021-1034 SN - 1879-1778 KW - Differential algebraic equations KW - Numerical methods KW - Stability ER - TY - JOUR TI - An integrated production planning model with load-dependent lead-times and safety stocks AU - Orcun, Seza AU - Uzsoy, Reha AU - Kempf, Karl G. T2 - COMPUTERS & CHEMICAL ENGINEERING AB - The divergence over the years of research paradigms addressing the production planning problem has led to the development of an extensive set of techniques, each of which can address a particular aspect of the practical problem and none of which provides a complete solution. In particular, most approaches fail to address the circular, non-linear dependency between resource utilization, lead-times and safety stocks. We present a non-linear programming formulation of the integrated problem using clearing functions that determines a work release schedule guaranteeing a specified service level in the face of stochastic demand. We introduce an iterative heuristic solution procedure that solves a relaxed LP approximation of the original NLP at each iteration to determine the lead-time profile to set safety-stock levels. Computational experiments suggest that our proposed iterative procedure performs well relative to conventional LP models that assume fixed, workload-independent lead-times. DA - 2009/12/10/ PY - 2009/12/10/ DO - 10.1016/j.compchemeng.2009.07.010 VL - 33 IS - 12 SP - 2159-2163 SN - 0098-1354 KW - Capacity planning KW - Clearing function KW - Safety stock KW - Load-dependent lead-times KW - Linear programming ER - TY - JOUR TI - A Survey on Next Generation Mobile WiMAX Networks: Objectives, Features and Technical Challenges AU - Papapanagiotou, Ioannis AU - Toumpakaris, Dimitris AU - Lee, Jungwon AU - Devetsikiotis, Michael T2 - IEEE COMMUNICATIONS SURVEYS AND TUTORIALS AB - In order to meet the requirements of 4G mobile networks targeted by the cellular layer of IMT-advanced, next generation mobile WiMAX devices based on IEEE 802.16m will incorporate sophisticated signal processing, seamless handover functionalities between heterogeneous technologies and advanced mobility mechanisms. This survey provides a description of key projected features of the physical (PHY) and medium access control (MAC) layers of 802.16m, as a major candidate for providing aggregate rates at the range of Gbps to high-speed mobile users. Moreover, a new unified method for simulation modeling, namely the evaluation methodology (EVM), introduced in 802.16m, is also presented. DA - 2009/// PY - 2009/// DO - 10.1109/SURV.2009.090402 VL - 11 IS - 4 SP - 3-18 SN - 1553-877X KW - IEEE 802.16m KW - Mobile WiMAX Networks KW - Next Generation Wireless Networks KW - Broadband Wireless Access KW - Evaluation Methodology ER - TY - JOUR TI - Commitment-Based Service-Oriented Architecture AU - Singh, Munindar P. AU - Chopra, Amit K. AU - Desai, Nirmit T2 - COMPUTER AB - Existing service-oriented architectures are formulated in terms of low-level abstractions far removed from business services. In a new SOA, the components are business services and the connectors are patterns, modeled as commitments, that support key elements of service engagements. DA - 2009/11// PY - 2009/11// DO - 10.1109/MC.2009.347 VL - 42 IS - 11 SP - 72-79 SN - 0018-9162 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70350222918&partnerID=MN8TOARS ER - TY - CONF TI - A Robust fault tolerant control approach for LTI systems with actuator and sensor faults AU - Cai, X. J. AU - Wu, F. AB - In this paper, we study a robust fault-tolerant control (FTC) problem for linear systems with time varying actuator and sensor faults and propose an parameter-dependent solution by using L 2 gain optimization techniques. Using estimated faults from a fault detection and isolation (FDI) scheme, parameter-dependent robust FTC gain will be scheduled by fault magnitude to stabilize and optimize the faulty system under all possible fault scenarios. The synthesis condition of such a FTC control law will be formulated as linear matrix inequalities (LMIs) and can be solved efficiently by semi-definite programming techniques. A numerical example is used to demonstrate the proposed fault-tolerant control approach for a simple faulty systems with different fault levels and fault estimation error bounds. C2 - 2009/// C3 - CCDC 2009: 21st Chinese Control and Decision Conference, vols 1-6, Proceedings DA - 2009/// DO - 10.1109/ccdc.2009.5191903 SP - 890-895 ER - TY - JOUR TI - On Bandwidth Tiered Service AU - Rouskas, George N. AU - Baradwaj, Nikhil T2 - IEEE-ACM TRANSACTIONS ON NETWORKING AB - Many network operators offer some type of tiered service, in which users may select only from a small set of service levels (tiers). Such a service has the potential to simplify a wide range of core network functions, allowing the providers to scale their operations efficiently. In this work, we study a number of problem variants related to service tier selection. Our contributions include: (1) a faster algorithm for obtaining optimal service tiers; (2) a new formulation and optimal algorithm to optimize jointly the number and magnitude of each service tier; and (3) the concept of ??TDM emulation?? in which all service tiers are multiples of the same (software-configurable) bandwidth unit, and a suite of algorithms to select jointly the basic unit and service tiers. Our work provides a systematic framework for reasoning about and tackling algorithmically the general problem of service tier selection, and has applications to a number of networking contexts, including access networks (e.g., determining the tiers for ADSL, cable modem networks or PONs) and core networks (e.g., LSP sizing for MPLS networks). DA - 2009/12// PY - 2009/12// DO - 10.1109/TNET.2009.2017928 VL - 17 IS - 6 SP - 1780-1793 SN - 1063-6692 KW - Directional p-median KW - dynamic programming KW - optimization KW - Tiered service ER - TY - JOUR TI - Estimating LTL rates using publicly available empirical data AU - Kay, Michael G. AU - Warsing, Donald P. T2 - INTERNATIONAL JOURNAL OF LOGISTICS-RESEARCH AND APPLICATIONS AB - We develop a shipper-oriented model to estimate less-than-truckload (LTL) truck rates for transporting goods between origin–destination (O–D) pairs located anywhere in the continental United States. The rate estimate is developed from internet-accessible tariff tables and allows straightforward computation of optimal shipment sizes (minimising total logistics costs) and comparison with the total cost of other modes. The model uses publicly available nominal rates along with a characterisation of the distribution of LTL shipments, based on other publicly available data, to determine a rate that also accounts for the estimated industry average discount from the nominal rate. We use nonlinear regression to build the estimate, with tariff-based rates serving as the dependent variable and load density, shipment weight, and O–D pair distance as the explanatory variables. The model is normalised to reflect average industry rates and current economic conditions using the Producer Price Index for LTL service. Although our results are specific to US markets for truck freight, the method of analysis serves as a model for similar international studies. DA - 2009/// PY - 2009/// DO - 10.1080/13675560802392415 VL - 12 IS - 3 SP - 165-193 SN - 1469-848X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-67650902017&partnerID=MN8TOARS KW - freight transportation KW - tariff rates KW - less-than-truckload KW - nonlinear regression ER - TY - CONF TI - Bayesian nonparametric approach to multiple testing AU - Ghosal, S. AU - Roy, A. C2 - 2009/// C3 - Perspectives in mathematical sciences i: probability and statistics DA - 2009/// VL - 7 SP - 139-164 ER - TY - CONF TI - An empirical study of security problem reports in Linux distributions AU - Anbalagan, P. AU - Vouk, M. C2 - 2009/// C3 - International symposium on empirical software engineering and DA - 2009/// SP - 482-485 ER - TY - JOUR TI - The credit risk(+) model with general sector correlations AU - Deshpande, Amogh AU - Iyer, Srikanth K. T2 - CENTRAL EUROPEAN JOURNAL OF OPERATIONS RESEARCH DA - 2009/6// PY - 2009/6// DO - 10.1007/s10100-009-0084-4 VL - 17 IS - 2 SP - 219-228 SN - 1613-9178 KW - Credit risk(+) KW - Compound gamma distribution KW - Value at risk KW - Risk contribution KW - Correlation KW - Portfolio loss distribution KW - Moment generating function ER - TY - JOUR TI - Pseudo-transient continuation for nonlinear transient elasticity AU - Gee, Michael W. AU - Kelley, C. T. AU - Lehoucq, R. B. T2 - INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING AB - Abstract This paper demonstrates how pseudo‐transient continuation improves the efficiency and robustness of a Newton iteration within a non‐linear transient elasticity simulation. Pseudo‐transient continuation improves efficiency by enabling larger time steps than possible with a Newton iteration. Robustness improves because pseudo‐transient continuation recovers the convergence of Newton's method when the initial iterate is not within the region of local convergence. We illustrate the benefits of pseudo‐transient continuation on a non‐linear transient simulation of a buckling cylinder, including a comparison with a line search‐based Newton iteration. Copyright © 2008 John Wiley & Sons, Ltd. DA - 2009/6/4/ PY - 2009/6/4/ DO - 10.1002/nme.2527 VL - 78 IS - 10 SP - 1209-1219 SN - 1097-0207 KW - transient elasticity KW - finite element approximation KW - pseudo-transient continuation KW - Newton's method ER - TY - JOUR TI - ON q-SERIES IDENTITIES ARISING FROM LECTURE HALL PARTITIONS AU - Andrews, George E. AU - Corteel, Sylvie AU - Savage, Carla D. T2 - INTERNATIONAL JOURNAL OF NUMBER THEORY AB - In this paper, we highlight two q-series identities arising from the "five guidelines" approach to enumerating lecture hall partitions and give direct, q-series proofs. This requires two new finite corollaries of a q-analog of Gauss's second theorem. In fact, the method reveals stronger results about lecture hall partitions and anti-lecture hall compositions that are only partially explained combinatorially. DA - 2009/3// PY - 2009/3// DO - 10.1142/S1793042109002134 VL - 5 IS - 2 SP - 327-337 SN - 1793-0421 KW - Lecture hall partitions KW - q-analog of Gauss's second theorem ER - TY - JOUR TI - NCSU's Virtual Computing Lab: A Cloud Computing Solution AU - Schaffer, Henry E. AU - Averitt, Samuel F. AU - Hoit, Marc I. AU - Peeler, Aaron AU - Sills, Eric D. AU - Vouk, Mladen A. T2 - COMPUTER AB - The delivery of many diverse computing services over the Internet, with flexible provisioning, has led to much greater efficiency, substantial cost savings, and many ways to enable and empower end users. NCSU's own experience with cloud computing, through its Virtual Computing Lab, indicates that this approach would be beneficial to a much wider audience.ays to enable and empower end users. NCSU's own experience with cloud computing, through its Virtual Computing Lab, indicates that this approach would be beneficial to a much wider audience. DA - 2009/7// PY - 2009/7// DO - 10.1109/mc.2009.230 VL - 42 IS - 7 SP - 94-97 SN - 1558-0814 ER - TY - JOUR TI - Generalized mixed integer rounding inequalities: facets for infinite group polyhedra AU - Kianfar, Kiavash AU - Fathi, Yahya T2 - MATHEMATICAL PROGRAMMING DA - 2009/9// PY - 2009/9// DO - 10.1007/s10107-008-0216-y VL - 120 IS - 2 SP - 313-346 SN - 0025-5610 KW - Mixed integer rounding KW - Mixed integer programming KW - Infinite group polyhedron KW - Valid inequality KW - Facet ER - TY - JOUR TI - The Third International Conference of Quantitative Genetics AU - Weir, Bruce S. AU - Hill, William G. AU - Zhu, Jun AU - Zeng, Zhao-Bang T2 - GENETICA AB - The third International Conference of Quantitative Genetics was held at Zheijiang University, Hangzhou, China from August 18 to 24, 2007. The papers of invited speakers at the conference comprise this issue of Genetica. The first ICQG was held in Ames, Iowa in 1976 and the second in Raleigh, North Carolina in 1987. Since the conference in Raleigh statistical techniques then in their infancy, such as QTL mapping and MCMC analysis, have become standard but still developing practices. New molecular techniques have enabled individual genes contributing to variation in quantitative traits to be identified. The new technologies of genomics and gene expression arrays provide new opportunities to understand the genetic basis of quantitative characters, but also new problems in statistical inference. The application of quantitative genetics has broadened from primarily animal and plant breeding into the genetics of human disease and the analyses of natural populations and their evolution. Indeed, it is now often termed the genetics of complex traits, in recognition of the fact that most diseases, for example, are not determined by just one or a handful of genes. The death of quantitative genetics has been forecast for 40 years or more; but it lives on, strongly. The wide range of topics and methods discussed in these papers show the diversity of applications of quantitative genetics and of the technologies employed. The conference was run as a single session in order to foster interactions and exchange of ideas and problems among those working on these different systems, species and technologies. In addition a number of selected short papers were presented in the oral sessions and others as posters. There were a total of 201 delegates at the conference, including 129 from outside the home country, who had opportunity to see and hear about research in quantitative genetics in China. Zhejiang University is one of the five most highly ranked research institutions in China, and arose from the merger of four specialist universities in the city. A new campus is being built and part of the University is already on that site. The City of Hangzhou is one of the seven ancient capital cities of China, and has many attractive features, including the famed West Lake. It is the capital city of Zheijiang province and has a population of nearly 4 million. Participants in Hangzhou considered intervals of 10 or 20 years far too long to enable adequate discussion and review of a changing subject, and that 5 years should be aimed for. Accordingly, the fourth conference will be held in Edinburgh in 2012. Those from outside the University are grateful to Jun Zhu and to the large team of staff and students at Zheijiang University led by Longjian Fan who undertook all the work and were exposed to the stresses and strains of managing a successful large conference. The conference and social events were excellent and provided many visitors their first exposure to Chinese culture. We are also grateful to Ron B. S. Weir Department of Biostatistics, University of Washington, Seattle, WA 98915, USA DA - 2009/6// PY - 2009/6// DO - 10.1007/s10709-008-9315-1 VL - 136 IS - 2 SP - 211-212 SN - 1573-6857 ER - TY - JOUR TI - Online Switching Control of LFT Parameter-Dependent Systems AU - Dong, Ke AU - Wu, Fen T2 - JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME AB - To improve controlled performance and expand gain-scheduling control capability, we propose a switching control approach of linear fractional transformation parameter-dependent systems using multiple Lyapunov functions combined with online control techniques. At each switching instant, a gain-scheduled controller working for the next switching interval will be designed online. The switching control synthesis condition is formulated as linear matrix inequalities and can be solved efficiently, upon which the controller will be constructed. The online switching control scheme is demonstrated using an uninhabited combat aerospace vehicle problem. DA - 2009/3// PY - 2009/3// DO - 10.1115/1.3023140 VL - 131 IS - 2 SP - SN - 1528-9028 KW - control system synthesis KW - linear matrix inequalities KW - linear systems KW - Lyapunov methods KW - time-varying systems ER - TY - JOUR TI - On the Modeling of Honest Players in Reputation Systems AU - Zhang, Qing AU - Wei, Wei AU - Yu, Ting T2 - JOURNAL OF COMPUTER SCIENCE AND TECHNOLOGY DA - 2009/9// PY - 2009/9// DO - 10.1007/s11390-009-9271-y VL - 24 IS - 5 SP - 808-819 SN - 1860-4749 KW - reputation KW - trust KW - user behavior modeling KW - collusion-resilient behavior testing ER - TY - JOUR TI - Nonlinear H-infinity Control Designs with Axisymmetric Spacecraft Control AU - Zheng, Qian AU - Wu, Fen T2 - JOURNAL OF GUIDANCE CONTROL AND DYNAMICS AB - In this paper, we study nonlinear control of a spacecraft symmetric about its principal axis with two control torques. Using a computationally efficient H ∞ control design procedure, attitude stabilization and command tracking problems of the axisymmetric spacecraft are solved locally. The proposed nonlinear H ∞ control approach uses higher order Lyapunov functions and reformulates the difficult Hamilton―Jacobian―Isaacs inequalities as semidefinite optimization conditions. Sum-of-squares programming techniques are then applied to obtain computationally tractable solutions, from which nonlinear control laws will be constructed. The nonlinear H ∞ control designs for spacecraft are capable of exploiting the most suitable forms of Lyapunov functions for performance improvement. DA - 2009/// PY - 2009/// DO - 10.2514/1.40060 VL - 32 IS - 3 SP - 850-859 SN - 1533-3884 ER - TY - JOUR TI - Multi-new product competition in duopoly: A differential game analysis AU - Medhin, N. G. AU - Wan, W. T2 - Dynamic Systems and Applications DA - 2009/// PY - 2009/// VL - 18 IS - 2 SP - 161-178 ER - TY - JOUR TI - Minimizing transceivers in optical path networks AU - Iyer, Prashant AU - Dutta, Rudra AU - Savage, Carla D. T2 - JOURNAL OF OPTICAL NETWORKING AB - The problem of routing traffic on multihop clear optical channels and deciding the virtual topology of optical channels to form on a physical network of fibers to minimize the cost of electronic switching equipment has become known as traffic grooming in optical networks. Traffic grooming is recognized as an important research area, because the joint opto-electric routing problem is a hard one, yet necessary because of the large cost of pure electronic switching. This problem has been shown to be NP-complete (nondeterminstic polynomial complete) even for very simple practical topologies such as a path network. In previous work, we have shown that at least the subproblem of routing traffic on a given virtual topology to minimize electronic switching (NP-hard for path networks with arbitrary traffic matrices) becomes polynomial when the traffic on the path is restricted to be egress traffic, that is, all traffic requests are destined for a single egress node. In that work, the objective was to minimize the raw OEO (opto-electro-optic) metric (number of bits electronically switched per second) totaled over all network nodes. Of late, it has become clear that electronic switching equipment cost is best counted in quantized units, e.g., in the number of transceiver interfaces at network nodes. In this paper, we consider the traffic grooming problem in unidirectional, WDM path networks with the goal of minimizing the number of transceivers. We conclusively show that the problem is NP-hard, even under the restriction of the egress traffic model. In the case of egress traffic, we give a simple heuristic that will never be worse than twice the optimal. DA - 2009/5/1/ PY - 2009/5/1/ DO - 10.1364/JON.8.000454 VL - 8 IS - 5 SP - 454-461 SN - 1536-5379 ER - TY - JOUR TI - Measurement-based optimal resource allocation for network services with pricing differentiation AU - Kallitsis, M. G. AU - Michailidis, G. AU - Devetsikiotis, M. T2 - PERFORMANCE EVALUATION AB - In this paper, we introduce a model for allocating available resources in service-oriented network, with particular focus on delay sensitive services. The model is based on a pricing scheme for the offered services and also takes into consideration the quality of service requirements of each service class through a probabilistic delay-bound constraint. The proposed policy is dynamic in nature and relies on online measurements of the incoming traffic for adjusting the class allocations. We illustrate its performance and its robustness to various tuning parameters through an extensive simulation study that considers various simulation scenarios including experiments based on real network traces. DA - 2009/9// PY - 2009/9// DO - 10.1016/j.peva.2009.03.003 VL - 66 IS - 9-10 SP - 505-523 SN - 1872-745X KW - Resource allocation KW - Optimization KW - Measurement KW - Prediction ER - TY - JOUR TI - Experimental implementation of a hybrid nonlinear control design for magnetostrictive actuators AU - Oates, W. S. AU - Evans, P. G. AU - Smith, Ralph AU - Dapino, M. J. T2 - Journal of Dynamic Systems, Measurement, and Control DA - 2009/// PY - 2009/// DO - 10.21236/ada459020 VL - 131 IS - 4 ER - TY - JOUR TI - An additive Schwarz preconditioner for the mortar-type rotated Q(1) FEM for elliptic problems with discontinuous coefficients AU - Wang, Feng AU - Chen, Jinru AU - Xu, Wei AU - Li, Zhilin T2 - APPLIED NUMERICAL MATHEMATICS AB - In this paper, we propose an additive Schwarz preconditioner for the mortar-type rotated Q1 finite element method for second order elliptic partial differential equations with piecewise but discontinuous coefficients. The work here is an extension of the research presented in [L. Marcinkowski, Additive Schwarz method for mortar discretization of elliptic problems with P1 non-conforming elements, BIT 45 (2005) 375–394]. Our analysis is valid for rectangular or L-shaped domains, which are partitioned by rectangular subdomains and meshes. We have shown that our proposed method has a quasi-optimal convergence behavior, i.e., the condition number of the preconditioned problem is O((1+log(H/h))2), which is independent of the jump in the coefficient. Numerical experiments presented in this paper have confirmed our theoretical analysis. DA - 2009/7// PY - 2009/7// DO - 10.1016/j.apnum.2008.11.006 VL - 59 IS - 7 SP - 1657-1667 SN - 1873-5460 KW - Domain decomposition KW - Mortar finite element method KW - Additive Schwarz method KW - Rotated Q(1) element ER - TY - JOUR TI - Amoeba: A Methodology for Modeling and Evolving Cross-Organizational Business Processes AU - Desai, Nirmit AU - Chopra, Amit K. AU - Singh, Munindar P. T2 - ACM TRANSACTIONS ON SOFTWARE ENGINEERING AND METHODOLOGY AB - Business service engagements involve processes that extend across two or more autonomous organizations. Because of regulatory and competitive reasons, requirements for cross-organizational business processes often evolve in subtle ways. The changes may concern the business transactions supported by a process, the organizational structure of the parties participating in the process, or the contextual policies that apply to the process. Current business process modeling approaches handle such changes in an ad hoc manner, and lack a principled means for determining what needs to be changed and where. Cross-organizational settings exacerbate the shortcomings of traditional approaches because changes in one organization can potentially affect the workings of another. This article describes Amoeba, a methodology for business processes that is based on business protocols . Protocols capture the business meaning of interactions among autonomous parties via commitments. Amoeba includes guidelines for (1) specifying cross-organizational processes using business protocols, and (2) handling the evolution of requirements via a novel application of protocol composition. This article evaluates Amoeba using enhancements of a real-life business scenario of auto-insurance claim processing, and an aerospace case study. DA - 2009/10// PY - 2009/10// DO - 10.1145/1571629.1571632 VL - 19 IS - 2 SP - SN - 1557-7392 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70350223832&partnerID=MN8TOARS KW - Design KW - Business process modeling KW - requirements evolution KW - business protocols ER - TY - JOUR TI - Special Issue on Advances in Broadband Wireless Networks AU - Wang, Wenye AU - Devetsikiotis, Michael T2 - MOBILE NETWORKS & APPLICATIONS DA - 2009/8// PY - 2009/8// DO - 10.1007/s11036-009-0159-4 VL - 14 IS - 4 SP - 365-367 SN - 1383-469X ER - TY - JOUR TI - Regional stabilisation of polynomial non-linear systems using rational Lyapunov functions AU - Zheng, Qian AU - Wu, Fen T2 - INTERNATIONAL JOURNAL OF CONTROL AB - In this article, we propose a new non-linear stabilisation approach based on the popular linear parameter-varying control techniques. The regional state-feedback control problem of polynomial non-linear systems will be studied using rational Lyapunov functions of states. By bounding the variation rates of each state, the domain of attraction will be embedded in the region specified by the non-linear vector field. As a result, the state-feedback stabilisation conditions will be formulated as a set of polynomial matrix inequalities and can be solved efficiently by sum-of-squares programming. The resulting Lyapunov matrix and state-feedback gains are typically state-dependent rational matrix functions. This approach is also extended to a class of output-dependent non-linear systems where the stabilising output-feedback controller can be synthesised using rational Lyapunov functions of outputs. Finally, several examples will be used to demonstrate the proposed stabilisation approach and clarify the effect of various choices of Lyapunov function forms and state constraints. DA - 2009/// PY - 2009/// DO - 10.1080/00207170802627267 VL - 82 IS - 9 SP - 1605-1615 SN - 1366-5820 KW - polynomial non-linear systems KW - rational Lyapunov function KW - domain of attraction KW - regional stabilisation KW - SOS programming ER - TY - JOUR TI - Quasivelocities and symmetries in non-holonomic systems AU - Bloch, Anthony M. AU - Marsden, Jerrold E. AU - Zenkov, Dmitry V. T2 - DYNAMICAL SYSTEMS-AN INTERNATIONAL JOURNAL AB - This article is concerned with the theory of quasivelocities for non-holonomic systems. The equations of non-holonomic mechanics are derived using the Lagrange–d'Alembert principle written in an arbitrary configuration-dependent frame. The article also shows how quasivelocities may be used in the formulation of non-holonomic systems with symmetry. In particular, the use of quasivelocities in the analysis of symmetry that leads to unusual momentum conservation laws is investigated, as is the applications of these conservation laws and discrete symmetries to the qualitative analysis of non-holonomic dynamics. The relationship between asymptotic dynamics and discrete symmetries of the system is also elucidated. DA - 2009/// PY - 2009/// DO - 10.1080/14689360802609344 VL - 24 IS - 2 SP - 187-222 SN - 1468-9375 KW - Hamel equations KW - momentum KW - symmetry ER - TY - JOUR TI - Quantification of hysteresis and nonlinear effects on the frequency response of ferroelectric and ferromagnetic materials AU - Stuebner, M. AU - Atulasimha, J. AU - Smith, R. C. T2 - SMART MATERIALS AND STRUCTURES AB - Ferroelectric (e.g., PZT and PMN) and ferromagnetic (e.g., Terfenol-D) materials exhibit high energy densities, broadband drive capabilities, and the capacity for both actuating and sensing. This makes them attractive as compact transducers for a wide range of applications. However, the materials also exhibit hysteresis and constitutive nonlinearities, at all drive levels, that must be quantified and accommodated to achieve stringent tracking requirements. Whereas considerable effort has been made on model development and understanding these materials in the parameter space and time domain, comprehensive quantification of these effects in the frequency domain is currently lacking. In this paper, we employ the homogenized energy model, in combination with thin beam theory, to quantify the frequency domain behavior of ferroelectric and ferromagnetic materials. This model combines energy analysis at the lattice level with stochastic homogenization techniques to provide a framework that effectively quantifies the effect of hysteresis, constitutive nonlinearities, bias fields and AC drive levels on the material dynamics in both the time and frequency domains. Aspects of the model are illustrated and validated through numerical and experimental examples. DA - 2009/10// PY - 2009/10// DO - 10.1088/0964-1726/18/10/104019 VL - 18 IS - 10 SP - SN - 1361-665X ER - TY - JOUR TI - Multiple interval mapping for gene expression QTL analysis AU - Zou, Wei AU - Zeng, Zhao-Bang T2 - GENETICA DA - 2009/11// PY - 2009/11// DO - 10.1007/s10709-009-9365-z VL - 137 IS - 2 SP - 125-134 SN - 1573-6857 KW - eQTL KW - FDR KW - MIM KW - Model selection ER - TY - JOUR TI - Monitoring autocorrelated processes using a distribution-free tabular CUSUM chart with automated variance estimation AU - Lee, Joongsup AU - Alexopoulos, Christos AU - Goldsman, David AU - Kim, Seong-Hee AU - Tsui, Kwok-Leung AU - Wilson, James R. T2 - IIE TRANSACTIONS AB - We formulate and evaluate distribution-free statistical process control (SPC) charts for monitoring shifts in the mean of an autocorrelated process when a training data set is used to estimate the marginal variance of the process and the variance parameter (i.e., the sum of covariances at all lags). Two alternative variance estimators are adapted for automated use in DFTC-VE, a distribution-free tabular CUSUM chart, based on the simulation-analysis methods of standardized time series and a simplified combination of autoregressive representation and non-overlapping batch means. Extensive experimentation revealed that these variance estimators did not seriously degrade DFTC-VE's performance compared with its performance using the exact values of the marginal variance and the variance parameter. Moreover, DFTC-VE's performance compared favorably with that of other competing distribution-free SPC charts. [Supplementary materials are available for this article. Go to the publisher's online edition of IIE Transactions for the following free supplementary resource: Appendix] DA - 2009/11// PY - 2009/11// DO - 10.1080/07408170902906035 VL - 41 IS - 11 SP - 979-994 SN - 1545-8830 KW - Statistical process control KW - Shewhart chart KW - tabular CUSUM chart KW - autocorrelated data KW - average run length KW - distribution-free statistical methods KW - variance estimation ER - TY - JOUR TI - Lyapunov Redesign of Adaptive Controllers for Polynomial Nonlinear Systems AU - Zheng, Qian AU - Wu, Fen T2 - 2009 AMERICAN CONTROL CONFERENCE, VOLS 1-9 AB - In this paper, we study adaptive control redesign problem of polynomial nonlinear systems with matching parametric uncertainties. By transforming the system into its corresponding error dynamics, we will develop an adaptive control scheme in attenuating the effect of the unknown parameters on the controlled output, which is composed of tracking errors and control efforts. To achieve better controlled performance, the Lyapunov functions will be relaxed from quadratic to higher order and the resulting controller gain is generalized from constant to parameter dependent. The synthesis conditions of adaptive control will be formulated as polynomial matrix inequalities and are solvable by recast the resulting conditions into a Sum of Squares (SOS) optimization problem, from which the adaptive control law as well as the parameter adaptation law are derived with zero tracking and parameter estimation errors. An example is provided to demonstrate effectiveness of the proposed adaptive control redesign approach. DA - 2009/// PY - 2009/// DO - 10.1109/acc.2009.5160128 SP - 5144-5149 SN - 2378-5861 KW - Adaptive control KW - parametric uncertainties KW - higher-order Lyapunov function KW - SOS programming ER - TY - JOUR TI - Global optimization for a class of fractional programming problems AU - Fang, Shu-Cherng AU - Gao, David Y. AU - Sheu, Ruey-Lin AU - Xing, Wenxun T2 - JOURNAL OF GLOBAL OPTIMIZATION DA - 2009/11// PY - 2009/11// DO - 10.1007/s10898-008-9378-7 VL - 45 IS - 3 SP - 337-353 SN - 1573-2916 KW - Quadratic fractional programming KW - Sum-of-ratios KW - Global optimization KW - Canonical duality ER - TY - JOUR TI - Convergence Analysis of Sampling Methods for Perturbed {L}ipschitz Functions AU - Finkel, D E AU - Kelley, C T T2 - Pacific J. Opt. DA - 2009/// PY - 2009/// VL - 5 IS - 2 SP - 339-350 ER - TY - JOUR TI - Contribution of genetic effects to genetic variance components with epistasis and linkage disequilibrium AU - Wang, Tao AU - Zeng, Zhao-Bang T2 - BMC GENETICS AB - Cockerham genetic models are commonly used in quantitative trait loci (QTL) analysis with a special feature of partitioning genotypic variances into various genetic variance components, while the F(infinity) genetic models are widely used in genetic association studies. Over years, there have been some confusion about the relationship between these two type of models. A link between the additive, dominance and epistatic effects in an F(infinity) model and the additive, dominance and epistatic variance components in a Cockerham model has not been well established, especially when there are multiple QTL in presence of epistasis and linkage disequilibrium (LD).In this paper, we further explore the differences and links between the F(infinity) and Cockerham models. First, we show that the Cockerham type models are allelic based models with a special modification to correct a confounding problem. Several important moment functions, which are useful for partition of variance components in Cockerham models, are also derived. Next, we discuss properties of the Finfinity models in partition of genotypic variances. Its difference from that of the Cockerham models is addressed. Finally, for a two-locus biallelic QTL model with epistasis and LD between the loci, we present detailed formulas for calculation of the genetic variance components in terms of the additive, dominant and epistatic effects in an F(infinity) model. A new way of linking the Cockerham and F(infinity) model parameters through their coding variables of genotypes is also proposed, which is especially useful when reduced F(infinity) models are applied.The Cockerham type models are allele-based models with a focus on partition of genotypic variances into various genetic variance components, which are contributed by allelic effects and their interactions. By contrast, the F(infinity) regression models are genotype-based models focusing on modeling and testing of within-locus genotypic effects and locus-by-locus genotypic interactions. When there is no need to distinguish the paternal and maternal allelic effects, these two types of models are transferable. Transformation between an F(infinity) model's parameters and its corresponding Cockerham model's parameters can be established through a relationship between their coding variables of genotypes. Genetic variance components in terms of the additive, dominance and epistatic genetic effects in an F(infinity) model can then be calculated by translating formulas derived for the Cockerham models. DA - 2009/9/4/ PY - 2009/9/4/ DO - 10.1186/1471-2156-10-52 VL - 10 SP - SN - 1471-2156 ER - TY - JOUR TI - Completions of implicitly defined linear time varying vector fields AU - Okay, Irfan AU - Campbell, Stephen L. AU - Kunkel, Peter T2 - LINEAR ALGEBRA AND ITS APPLICATIONS AB - The stabilization of constraints through such techniques as Baumgarte stabilization has been used in the simulation community for some time. This and a number of control problems can be viewed as either extending, or modifying, a vector field off of some manifold. Generally these approaches required the equations to have a special structure. Motivated by numerical simulation there has recently been new progress on doing this stabilization in numerically robust ways for larger classes of systems. In this paper we point out how earlier linear time invariant results do not immediately apply to the linear time varying case and then analyze the linear time varying case. DA - 2009/10/1/ PY - 2009/10/1/ DO - 10.1016/j.laa.2009.05.006 VL - 431 IS - 9 SP - 1422-1438 SN - 1873-1856 KW - Differential algebraic equations KW - Numerical methods KW - Linear systems KW - Stability ER - TY - JOUR TI - ASYMPTOTIC PROPERTIES OF FEEDBACK SOLUTIONS FOR A CLASS OF QUANTUM CONTROL PROBLEMS AU - Ito, Kazufumi AU - Kunisch, Karl T2 - SIAM JOURNAL ON CONTROL AND OPTIMIZATION AB - Control of quantum systems described by the Schrödinger equation is considered. Feedback control laws are developed for orbit tracking via controlled Hamiltonians, and their asymptotic properties are analyzed. Numerical integration via time splitting is also investigated and used to demonstrate the feasibility of the proposed feedback laws. DA - 2009/// PY - 2009/// DO - 10.1137/080720784 VL - 48 IS - 4 SP - 2323-2343 SN - 1095-7138 KW - feedback control KW - asymptotic tracking KW - Schrodinger equations ER - TY - JOUR TI - A smoothing technique for discrete delta functions with application to immersed boundary method in moving boundary simulations AU - Yang, Xiaolei AU - Zhang, Xing AU - Li, Zhilin AU - He, Guo-Wei T2 - JOURNAL OF COMPUTATIONAL PHYSICS AB - The effects of complex boundary conditions on flows are represented by a volume force in the immersed boundary methods. The problem with this representation is that the volume force exhibits non-physical oscillations in moving boundary simulations. A smoothing technique for discrete delta functions has been developed in this paper to suppress the non-physical oscillations in the volume forces. We have found that the non-physical oscillations are mainly due to the fact that the derivatives of the regular discrete delta functions do not satisfy certain moment conditions. It has been shown that the smoothed discrete delta functions constructed in this paper have one-order higher derivative than the regular ones. Moreover, not only the smoothed discrete delta functions satisfy the first two discrete moment conditions, but also their derivatives satisfy one-order higher moment condition than the regular ones. The smoothed discrete delta functions are tested by three test cases: a one-dimensional heat equation with a moving singular force, a two-dimensional flow past an oscillating cylinder, and the vortex-induced vibration of a cylinder. The numerical examples in these cases demonstrate that the smoothed discrete delta functions can effectively suppress the non-physical oscillations in the volume forces and improve the accuracy of the immersed boundary method with direct forcing in moving boundary simulations. DA - 2009/11/1/ PY - 2009/11/1/ DO - 10.1016/j.jcp.2009.07.023 VL - 228 IS - 20 SP - 7821-7836 SN - 1090-2716 KW - Immersed boundary method KW - Moving boundary KW - Non-physical force oscillations KW - Smoothed discrete delta function ER - TY - JOUR TI - A discrete-time queueing network model of a hub-based OBS architecture AU - Mountrouidou, Xenia AU - Perros, Harry T2 - TELECOMMUNICATION SYSTEMS DA - 2009/7// PY - 2009/7// DO - 10.1007/s11235-009-9157-x VL - 41 IS - 3 SP - 173-184 SN - 1572-9451 KW - Optical Burst Switching KW - Hub KW - Queueing network KW - Burst aggregation KW - Decomposition algorithm ER - TY - JOUR TI - Some additive results on Drazin inverses AU - Patricio, P. AU - Hartwig, R. E. T2 - Applied Mathematics and Computation AB - In this paper, some additive results on Drazin inverse of a sum of Drazin invertible elements are derived. Some converse results are also presented. DA - 2009/// PY - 2009/// DO - 10.1016/j.amc.2009.05.021 VL - 215 IS - 2 SP - 530-538 ER - TY - JOUR TI - On the existence of symmetric chain decompositions in a quotient of the Boolean lattice AU - Jiang, Zongliang AU - Savage, Carla D. T2 - DISCRETE MATHEMATICS AB - We highlight a question about binary necklaces, i.e., equivalence classes of binary strings under rotation. Is there a way to choose representatives of the n-bit necklaces so that the subposet of the Boolean lattice induced by those representatives has a symmetric chain decomposition? Alternatively, is the quotient of the Boolean lattice Bn, under the action of the cyclic group Zn, a symmetric chain order? The answer is known to be yes for all prime n and for composite n≤18, but otherwise the question appears to be open. In this note we describe how it suffices to focus on subposets induced by necklaces with periodic block codes, substantially reducing the size of the problem. We mention a motivating application: determining whether minimum-region rotationally symmetric independent families of n curves exist for all n. DA - 2009/9/6/ PY - 2009/9/6/ DO - 10.1016/j.disc.2007.11.036 VL - 309 IS - 17 SP - 5278-5283 SN - 1872-681X KW - Symmetric chain decompositions KW - Necklaces KW - Quotients of the Boolean lattice ER - TY - JOUR TI - OPTIMAL STOPPING PROBLEM FOR STOCHASTIC DIFFERENTIAL EQUATIONS WITH RANDOM COEFFICIENTS AU - Chang, Mou-Hsiung AU - Pang, Tao AU - Yong, Jiongmin T2 - SIAM JOURNAL ON CONTROL AND OPTIMIZATION AB - An optimal stopping problem for stochastic differential equations with random coefficients is considered. The dynamic programming principle leads to a Hamiltion–Jacobi–Bellman equation, which, for the current case, is a backward stochastic partial differential variational inequality (BSPDVI, for short) for the value function. Well-posedness of such a BSPDVI is established, and a verification theorem is proved. DA - 2009/// PY - 2009/// DO - 10.1137/070705726 VL - 48 IS - 2 SP - 941-971 SN - 1095-7138 KW - optimal stopping KW - random coefficients KW - dynamic programming principle KW - backward stochastic partial differential variational inequality KW - verification theorem ER - TY - JOUR TI - LAGRANGE MULTIPLIER APPROACH WITH OPTIMIZED FINITE DIFFERENCE STENCILS FOR PRICING AMERICAN OPTIONS UNDER STOCHASTIC VOLATILITY AU - Ito, Kazufumi AU - Toivanen, Jari T2 - SIAM JOURNAL ON SCIENTIFIC COMPUTING AB - The deterministic numerical valuation of American options under Heston's stochastic volatility model is considered. The prices are given by a linear complementarity problem with a two-dimensional parabolic partial differential operator. A new truncation of the domain is described for small asset values, while for large asset values and variance a standard truncation is used. The finite difference discretization is constructed by numerically solving a quadratic optimization problem aiming to minimize the truncation error at each grid point. A Lagrange approach is used to treat the linear complementarity problems. Numerical examples demonstrate the accuracy and effectiveness of the proposed approach. DA - 2009/// PY - 2009/// DO - 10.1137/07070574X VL - 31 IS - 4 SP - 2646-2664 SN - 1095-7197 KW - American option pricing KW - stochastic volatility model KW - linear complementarity problem KW - finite difference method KW - quadratic programming KW - multigrid method KW - Lagrange method KW - penalty method ER - TY - JOUR TI - Edge-Reconfigurable Optical Networks (ERONs): Rationale, Network Design, and Evaluation AU - Karmous-Edwards, Gigi AU - Vishwanath, Arun AU - Reeves, Douglas S. AU - Battestilli, Lina AU - Vegesna, Priyanka B. AU - Rouskas, George N. T2 - JOURNAL OF LIGHTWAVE TECHNOLOGY AB - To bridge the gap between the current practice of setting up expensive, dedicated, lightpath connections (i.e., static topologies), and the distant future vision of inexpensive access to dynamically switched end-to-end lightpaths, we propose a medium term solution in the form of edge-reconfigurable optical networks (ERONs) . An ERON is an overlay-control network created by installing readily available MEMS optical switches, and implementing a GMPLS control plane at sites interconnected by static lightpaths. The switches and control software are deployed at the edge of the network and operated by the organization-user (i.e., outside the network provider's control), hence the term ldquoedge-reconfigurablerdquo. By providing dynamic, automated control of end-to-end lightpaths, ERONs enable the sharing of expensive network resources among multiple users and applications that require sporadic access to these resources. We develop an algorithm for creating an ERON from an existing topology of static lightpaths. We also present simulation results that quantify the benefits of ERONs, in terms of the number of lightpaths that are needed when compared to a static configuration of independent and dedicated circuits. DA - 2009/6/15/ PY - 2009/6/15/ DO - 10.1109/JLT.2009.2021279 VL - 27 IS - 12 SP - 1837-1845 SN - 1558-2213 KW - Dynamic circuits KW - network design KW - optical networks ER - TY - JOUR TI - Economic analysis of US textile production activities under the North American Free Trade Agreement AU - Lim, M. AU - Suh, M. W. AU - Gaskill, L. T2 - JOURNAL OF THE TEXTILE INSTITUTE AB - This economic analysis investigates the US textile industry's output supply and input demand pattern under the influence of North American Free Trade Agreement (NAFTA) and determines the significance of the agreement on the industry. This analysis employs the normalized restricted translog profit model as an analytical tool and introduces a time dummy variable in the model to distinguish the pre- and post-NAFTA years. The outcome of analysis shows the significant but negative effect of NAFTA on the industry's profit performance in the early years of the agreement, probably due to intensified import competition, fall of real output prices, and numerous mill closings. NAFTA, however, is identified as less significant than variable input prices of labor, material, and electricity. The elasticity estimates show the dominant role of maintenance and capital expenditures, followed by textile output and variable input prices in order, in determining the industry's output supply and input demand. Overall, NAFTA is identified as a short-term solution to the US textile industry's fundamental problems of high labor costs and declining price competitiveness. DA - 2009/// PY - 2009/// DO - 10.1080/00405000802125170 VL - 100 IS - 7 SP - 612-625 SN - 0040-5000 KW - economic analysis KW - NAFTA KW - textile production KW - normalized restricted translog profit model ER - TY - JOUR TI - An update on the middle levels problem AU - Shields, Ian AU - Shields, Brendan J. AU - Savage, Carla D. T2 - DISCRETE MATHEMATICS AB - The middle levels problem is to find a Hamilton cycle in the middle levels, M2k+1, of the Hasse diagram of B2k+1 (the partially-ordered set of subsets of a 2k+1-element set ordered by inclusion). Previously, the best known, from [I. Shields, C.D. Savage, A Hamilton path heuristic with applications to the middle two levels problem, in: Proceedings of the Thirtieth Southeastern International Conference on Combinatorics, Graph Theory, and Computing (Boca Raton, FL, 1999), vol. 140, 1999], was that M2k+1 is Hamiltonian for all positive k through k=15. In this note we announce that M33 and M35 have Hamilton cycles. The result was achieved by an algorithmic improvement that made it possible to find a Hamilton path in a reduced graph (of complementary necklace pairs) having 129,644,790 vertices, using a 64-bit personal computer. DA - 2009/9/6/ PY - 2009/9/6/ DO - 10.1016/j.disc.2007.11.010 VL - 309 IS - 17 SP - 5271-5277 SN - 0012-365X KW - Hamilton cycles KW - Middle levels KW - Boolean lattice KW - Necklaces ER - TY - JOUR TI - Probabilistic Cost-Effectiveness Comparison of Screening Strategies for Colorectal Cancer AU - Tafazzoli, Ali AU - Roberts, Stephen AU - Klein, Robert AU - Ness, Reid AU - Dittus, Robert T2 - ACM TRANSACTIONS ON MODELING AND COMPUTER SIMULATION AB - A stochastic discrete-event simulation model of the natural history of Colorectal Cancer (CRC) is augmented with screening technology representations to create a base for simulating various screening strategies for CRC. The CRC screening strategies recommended by the American Gastroenterological Association (AGA) and the newest screening strategies for which clinical efficacy has been established are simulated. In addition to verification steps, validation of screening is pursued by comparison with the Minnesota Colon Cancer Control Study. The model accumulates discounted costs and quality-adjusted life-years. The natural variability in the modeled random variables for natural history is conditioned using a probabilistic sensitivity analysis through a two-stage sampling process that adds other random variables representing parametric uncertainty. The analysis of the screening alternatives in a low-risk population explores both deterministic and stochastic dominance to eliminate some screening alternatives. Net benefit analysis, based on willingness to pay for quality-adjusted life-years, is used to compare the most cost-effective strategies through acceptability curves and to make a screening recommendation. Methodologically, this work demonstrates how variability from the natural variation in the development, screening, and treatment of a disease can be combined with the variation in parameter uncertainty. Furthermore, a net benefit analysis that characterizes cost-effectiveness alternatives can explicitly depend on variation from all sources producing a probabilistic cost-effectiveness analysis of decision alternatives. DA - 2009/3// PY - 2009/3// DO - 10.1145/1502787.1502789 VL - 19 IS - 2 SP - SN - 1558-1195 KW - Cost-effectiveness analysis KW - probabilistic sensitivity analysis KW - net benefit analysis KW - acceptability curves KW - colorectal cancer screening strategies KW - medical decision making ER - TY - JOUR TI - On the shape derivative for problems of Bernoulli type AU - Haslinger, J. AU - Ito, K. AU - Kozubek, T. AU - Kunisch, K. AU - Peichl, G. T2 - Interfaces and Free Boundaries AB - The shape derivative of the cost functional in a Bernoulli-type problem is characterized. The calculation of the derivative of the cost does not use the shape derivative of the state variable and is achieved under mild regularity conditions on the boundary of the domain. DA - 2009/// PY - 2009/// DO - 10.4171/ifb/213 VL - 11 IS - 2 SP - 317-330 ER - TY - JOUR TI - Coupling winds to ocean surface currents over the global ocean AU - Deng, Zengan AU - Xie, Lian AU - Liu, Bin AU - Wu, Kejian AU - Zhao, Dongliang AU - Yu, Ting T2 - OCEAN MODELLING AB - A Wind stress–Current Coupled System (WCCS) consisting of the HYbrid Coordinate Ocean Model (HYCOM) and an improved wind stress algorithm based on Donelan et al. [Donelan, W.M., Drennan, Katsaros, K.B., 1997. The air–sea momentum flux in mixed wind sea and swell conditions. J. Phys. Oceanogr. 27, 2087–2099] is developed by using the Earth System Modeling Framework (ESMF). The WCCS is applied to the global ocean to study the interactions between the wind stress and the ocean surface currents. In this study, the ocean surface current velocity is taken into consideration in the wind stress calculation and air–sea heat flux calculation. The wind stress that contains the effect of ocean surface current velocity will be used to force the HYCOM. The results indicate that the ocean surface velocity exerts an important influence on the wind stress, which, in turn, significantly affects the global ocean surface currents, air–sea heat fluxes, and the thickness of ocean surface boundary layer. Comparison with the TOGA TAO buoy data, the sea surface temperature from the wind–current coupled simulation showed noticeable improvement over the stand-alone HYCOM simulation. DA - 2009/// PY - 2009/// DO - 10.1016/j.ocemod.2009.05.003 VL - 29 IS - 4 SP - 261-268 SN - 1463-5011 KW - Wind-Current Coupled System KW - HYCOM KW - Wind stress KW - Heat flux KW - Ocean surface boundary layer KW - ESMF KW - Ocean current ER - TY - JOUR TI - Topology Stability Analysis and Its Application in Hierarchical Mobile Ad Hoc Networks AU - Xu, Yi AU - Wang, Wenye T2 - IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY AB - The hierarchical architecture has been proven effective for solving the scalability problems in large-scale ad hoc networks. The stability of the hierarchical architecture is a key factor in determining the network performance. Although many solutions have been proposed to construct stable clusters, the maximum stability achievable in mobile environments is still unknown. In this paper, we define three metrics for measuring network stability: (1) the cluster lifetime;(2) the intercluster link lifetime; and (3) the end-to-end path lifetime. We model and analyze the maximum of these lifetimes under the constraint of random node mobility. Analytical results provide the fundamental understanding of the bounds on network stability. Inspired by this understanding, we propose a clustering algorithm and a hierarchical routing protocol that work together to achieve the maximum network stability. The analytical results are verified by simulations. DA - 2009/3// PY - 2009/3// DO - 10.1109/TVT.2008.928006 VL - 58 IS - 3 SP - 1546-1560 SN - 1939-9359 KW - Clustering KW - hierarchical architecture KW - mobility network topology KW - wireless ad hoc networks ER - TY - JOUR TI - Strategic purchasing, supply management practices and buyer performance improvement: an empirical study of UK manufacturing organisations AU - Lawson, Benn AU - Cousins, Paul D. AU - Handfield, Robert B. AU - Petersen, Kenneth J. T2 - INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH AB - Purchasing is increasingly seen as an important strategic activity of the firm. However, there is little evidence examining the effects of strategic purchasing on a firm's inter-organisational supply management practices and performance. The purpose of this paper is to examine the effect of strategic purchasing on the supply management practices of socialisation, supplier integration and supplier responsiveness, together with relationship performance. Using empirical data collected from 111 United Kingdom purchasing executives, a structural equation model is used to test the theoretical framework. The results provide support for four of the six hypotheses developed. Strategic purchasing was found to have an indirect, significant effect on improving buyer performance, acting through supplier integration. Strategic purchasing also had a significant effect on the use of socialisation mechanisms, but not on supplier responsiveness. Our research indicates that close, long-term supplier relationships can lead to the creation of relational rents. Implications for future research and suggestions for improving the rigour of strategic purchasing research are made. DA - 2009/// PY - 2009/// DO - 10.1080/00207540701694313 VL - 47 IS - 10 SP - 2649-2667 SN - 1366-588X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-70449569471&partnerID=MN8TOARS KW - buyer-supplier relationships KW - strategic purchasing KW - supply management KW - structural equation modelling 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 Sixth International Workshop on Accurate Solution of Eigenvalue Problems, which took place at The Pennsylvania State University from May 22–25, 2006. This special issue provides an outlet for papers from the workshop and recognizes advances in the numerical solution of eigenvalue and related problems. This is the second such special issue published in the SIAM Journal on Matrix Analysis and Applications; the first was published in number 4 of volume 28 in connection with the Fifth International Workshop on Accurate Solution of Eigenvalue Problems, which took place in Hagen, Germany, from June 29 to July 1, 2004. The twelve papers in the current issue are concerned with a variety of aspects that arise in the computation of eigenvalues and invariant subspaces: perturbation bounds and sensitivity, accuracy and convergence behavior of algorithms, exploitation of structure in matrices, and particular engineering applications. Thanks go to SIMAX Editor-in-Chief, Henk van der Vorst; guest editors Jesse Barlow, Froilán Dopico, and Zlatko Drmač, who put great effort into the careful and timely review of papers; and Mitch Chernoff, Cherie Trebisky, and other members of the SIAM staff who worked hard to publish this special issue. DA - 2009/// PY - 2009/// DO - 10.1137/sjmael000031000001000vii000001 VL - 31 IS - 1 SP - VII-VII SN - 1095-7162 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-73649094469&partnerID=MN8TOARS ER - TY - JOUR TI - REFINED PERTURBATION BOUNDS FOR EIGENVALUES OF HERMITIAN AND NON-HERMITIAN MATRICES AU - Ipsen, I. C. F. AU - Nadler, B. T2 - SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS AB - We present eigenvalue bounds for perturbations of Hermitian matrices and express the change in eigenvalues in terms of a projection of the perturbation onto a particular eigenspace, rather than in terms of the full perturbation. The perturbations we consider are Hermitian of rank one, and Hermitian or non-Hermitian with norm smaller than the spectral gap of a specific eigenvalue. Applications include principal component analysis under a spiked covariance model, and pseudo-arclength continuation methods for the solution of nonlinear systems. DA - 2009/// PY - 2009/// DO - 10.1137/070682745 VL - 31 IS - 1 SP - 40-53 SN - 0895-4798 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-73649111433&partnerID=MN8TOARS KW - eigenvalues KW - Hermitian matrix KW - eigenvalue gap KW - perturbation bounds KW - non-Hermitian perturbations KW - principal components KW - numerical continuation ER - TY - JOUR TI - More efficient optimization of long-term water supply portfolios AU - Kirsch, Brian R. AU - Characklis, Gregory W. AU - Dillard, Karen E. M. AU - Kelley, C. T. T2 - WATER RESOURCES RESEARCH AB - The use of temporary transfers, such as options and leases, has grown as utilities attempt to meet increases in demand while reducing dependence on the expansion of costly infrastructure capacity (e.g., reservoirs). Earlier work has been done to construct optimal portfolios comprising firm capacity and transfers, using decision rules that determine the timing and volume of transfers. However, such work has only focused on the short‐term (e.g., 1‐year scenarios), which limits the utility of these planning efforts. Developing multiyear portfolios can lead to the exploration of a wider range of alternatives but also increases the computational burden. This work utilizes a coupled hydrologic‐economic model to simulate the long‐term performance of a city's water supply portfolio. This stochastic model is linked with an optimization search algorithm that is designed to handle the high‐frequency, low‐amplitude noise inherent in many simulations, particularly those involving expected values. This noise is detrimental to the accuracy and precision of the optimized solution and has traditionally been controlled by investing greater computational effort in the simulation. However, the increased computational effort can be substantial. This work describes the integration of a variance reduction technique (control variate method) within the simulation/optimization as a means of more efficiently identifying minimum cost portfolios. Random variation in model output (i.e., noise) is moderated using knowledge of random variations in stochastic input variables (e.g., reservoir inflows, demand), thereby reducing the computing time by 50% or more. Using these efficiency gains, water supply portfolios are evaluated over a 10‐year period in order to assess their ability to reduce costs and adapt to demand growth, while still meeting reliability goals. As a part of the evaluation, several multiyear option contract structures are explored and compared. DA - 2009/3/19/ PY - 2009/3/19/ DO - 10.1029/2008wr007018 VL - 45 SP - SN - 0043-1397 ER - TY - JOUR TI - A well-conditioned augmented system for solving Navier-Stokes equations in irregular domains AU - Ito, Kazufumi AU - Lai, Ming-Chih AU - Li, Zhilin T2 - JOURNAL OF COMPUTATIONAL PHYSICS AB - An augmented method based on a Cartesian grid is proposed for the incompressible Navier–Stokes equations in irregular domains. The irregular domain is embedded into a rectangular one so that a fast Poisson solver can be utilized in the projection method. Unlike several methods suggested in the literature that set the force strengths as unknowns, which often results in an ill-conditioned linear system, we set the jump in the normal derivative of the velocity as the augmented variable. The new approach improves the condition number of the system for the augmented variable significantly. Using the immersed interface method, we are able to achieve second order accuracy for the velocity. Numerical results and comparisons to benchmark tests are given to validate the new method. A lid-driven cavity flow with multiple obstacles and different geometries are also presented. DA - 2009/4/20/ PY - 2009/4/20/ DO - 10.1016/j.jcp.2008.12.028 VL - 228 IS - 7 SP - 2616-2628 SN - 0021-9991 KW - Navier-Stokes equations KW - Embedding technique KW - Immersed interface method KW - Irregular domain KW - Augmented system KW - Projection method KW - Level set representation ER - TY - JOUR TI - Bayesian ROC curve estimation under binormality using a rank likelihood AU - Gu, J. Z. AU - Ghosal, S. T2 - Journal of Statistical Planning and Inference DA - 2009/// PY - 2009/// VL - 139 IS - 6 SP - 2076-2083 ER - TY - JOUR TI - Optimal Tracking Using Magnetostrictive Actuators Operating in Nonlinear and Hysteretic Regimes AU - Oates, William S. AU - Smith, Ralph C. T2 - JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME AB - Abstract Many active materials exhibit nonlinearities and hysteresis when driven at field levels necessary to meet stringent performance criteria in high performance applications. This often requires nonlinear control designs to effectively compensate for the nonlinear, hysteretic, field-coupled material behavior. In this paper, an optimal control design is developed to accurately track a reference signal using magnetostrictive transducers. The methodology can be directly extended to transducers employing piezoelectric materials or shape memory alloys due to the unified nature of the constitutive model employed in the control design. The constitutive model is based on a framework that combines energy analysis at lattice length scales with stochastic homogenization techniques to predict macroscopic material behavior. The constitutive model is incorporated into a finite element representation of the magnetostrictive transducer, which provides the framework for developing the finite-dimensional nonlinear control design. The control design includes an open loop nonlinear component computed off-line with perturbation feedback around the optimal state trajectory. Estimation of immeasurable states is achieved using a Kalman filter. It is shown that when operating in a highly nonlinear regime and as the frequency increases, significant performance enhancements are achieved relative to conventional proportional-integral control. DA - 2009/5// PY - 2009/5// DO - 10.1115/1.3072093 VL - 131 IS - 3 SP - SN - 0022-0434 KW - control system synthesis KW - feedback KW - intelligent materials KW - intelligent structures KW - Kalman filters KW - magnetostrictive devices KW - nonlinear control systems KW - open loop systems KW - optimal control KW - perturbation techniques KW - PI control KW - piezoelectric actuators KW - piezoelectric materials KW - piezoelectric transducers KW - shape memory effects KW - stochastic processes ER - TY - JOUR TI - A genetic algorithm for a single product network design model with lead time and safety stock considerations AU - Sourirajan, Karthik AU - Ozsen, Leyla AU - Uzsoy, Reha T2 - EUROPEAN JOURNAL OF OPERATIONAL RESEARCH AB - We consider a two-stage supply chain with a production facility that replenishes a single product at retailers. The objective is to locate distribution centers in the network such that the sum of facility location, pipeline inventory, and safety stock costs is minimized. We explicitly model the relationship between the flows in the network, lead times, and safety stock levels. We use genetic algorithms to solve the model and compare their performance to that of a Lagrangian heuristic developed in earlier work. A novel chromosome representation that combines binary vectors with random keys provides solutions of similar quality to those from the Lagrangian heuristic. The model is then extended to incorporate arbitrary demand variance at the retailers. This modification destroys the structure upon which the Lagrangian heuristic is based, but is easily incorporated into the genetic algorithm. The genetic algorithm yields significantly better solutions than a greedy heuristic for this modification and has reasonable computational requirements. DA - 2009/9/1/ PY - 2009/9/1/ DO - 10.1016/j.ejor.2008.07.038 VL - 197 IS - 2 SP - 599-608 SN - 1872-6860 KW - Supply chain KW - Network design KW - Lead time KW - Safety stock KW - Genetic algorithm ER - TY - JOUR TI - (Q, r) Inventory policies in a fuzzy uncertain supply chain environment AU - Handfield, Robert AU - Warsing, Don AU - Wu, Xinmin T2 - EUROPEAN JOURNAL OF OPERATIONAL RESEARCH AB - Managers have begun to recognize that effectively managing risks in their business operations plays an important role in successfully managing their inventories. Accordingly, we develop a (Q,r) model based on fuzzy-set representations of various sources of uncertainty in the supply chain. Sources of risk and uncertainty in our model include demand, lead time, supplier yield, and penalty cost. The naturally imprecise nature of these risk factors in managing inventories is represented using triangular fuzzy numbers. In addition, we introduce a human risk attitude factor to quantify the decision maker’s attitude toward the risk of stocking out during the replenishment period. The total cost of the inventory system is computed using defuzzification methods built from techniques identified in the literature on fuzzy sets. Finally, we provide numerical examples to compare our fuzzy-set computations with those generated by more traditional models that assume full knowledge of the distributions of the stochastic parameters in the system. DA - 2009/9/1/ PY - 2009/9/1/ DO - 10.1016/j.ejor.2008.07.016 VL - 197 IS - 2 SP - 609-619 SN - 1872-6860 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-60649115627&partnerID=MN8TOARS KW - (Q, r) System KW - Inventory KW - Fuzzy sets KW - Optimization ER - TY - CONF TI - Robust univariate cubic L-2 spines: Interpolating data with uncertain positions of measurements AU - Averbakh, I. AU - Fang, S. C. AU - Zhao, Y. B. C2 - 2009/// C3 - Journal of Industrial and Management Optimization DA - 2009/// VL - 5 SP - 351-361 M1 - 2 ER - TY - JOUR TI - Forecast updating and supplier coordination for complementary component purchases AU - Thomas, D. J. AU - Warsing, Donald AU - Zhang, X. Y. T2 - Production and Operations Management DA - 2009/// PY - 2009/// DO - 10.3401/poms.1080.01012 VL - 18 IS - 2 SP - 167–184 ER - TY - JOUR TI - A note on solution sets of interval-valued fuzzy relational equations AU - Li, Pingke AU - Fang, Shu-Cherng T2 - FUZZY OPTIMIZATION AND DECISION MAKING DA - 2009/3// PY - 2009/3// DO - 10.1007/s10700-009-9055-4 VL - 8 IS - 1 SP - 115-121 SN - 1573-2908 KW - Fuzzy relational equations KW - Fuzzy relational inequalities KW - Interval-valued system ER - TY - JOUR TI - The Impact of Revenue-Maximizing Priority Pricing on Customer Delay Costs AU - Gilland, Wendell G. AU - Warsing, Donald P. T2 - DECISION SCIENCES AB - ABSTRACT Speed is an increasingly important determinant of which suppliers will be given customers' business and is defined as the time between when an order is placed by the customer and when the product is delivered, or as the amount of time customers must wait before they receive their desired service. In either case, the speed a customer experiences can be enhanced by giving priority to that particular customer. Such a prioritization scheme will necessarily reduce the speed experienced by lower‐priority customers, but this can lead to a better outcome when different customers place different values on speed. We model a single resource (e.g., a manufacturer) that processes jobs from customers who have heterogeneous waiting costs. We analyze the price that maximizes priority revenue for the resource owner (i.e., supplier, manufacturer) under different assumptions regarding customer behavior. We discover that a revenue‐maximizing supplier facing self‐interested customers (i.e., those that independently minimize their own expected costs) charges a price that also minimizes the expected total delay costs across all customers and that this outcome does not result when customers coordinate to submit priority orders at a level that seeks to minimize their aggregate costs of priority fees and delays. Thus, the customers are better off collectively (as is the supplier) when the supplier and customers act independently in their own best interests. Finally, as the number of priority classes increases, both the priority revenues and the overall customer delay costs improve, but at a decreasing rate. DA - 2009/2// PY - 2009/2// DO - 10.1111/j.1540-5915.2008.00217.x VL - 40 IS - 1 SP - 89-120 SN - 0011-7315 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-61849115209&partnerID=MN8TOARS KW - Priority Pricing KW - Queueing Theory KW - and Supplier-Customer Relationships ER - TY - JOUR TI - Nonstationary analysis of the loss queue and of queueing networks of loss queues AU - Alnowibet, Khalid Abdulaziz AU - Perros, Harry T2 - EUROPEAN JOURNAL OF OPERATIONAL RESEARCH AB - We present an iterative scheme based on the fixed-point approximation method, for the numerical calculation of the time-dependent mean number of customers and blocking probability functions in a nonstationary queueing network with multi-rate loss queues. We first show how the proposed method can be used to analyze a single-class, multi-class, and multi-rate nonstationary loss queue. Subsequently, the proposed method is extended to the analysis of a nonstationary queueing network of multi-rate loss queues. Comparisons with exact and simulation results showed that the results are consistently close to the exact results and they are always within simulation confidence intervals. DA - 2009/8/1/ PY - 2009/8/1/ DO - 10.1016/j.ejor.2007.10.066 VL - 196 IS - 3 SP - 1015-1030 SN - 1872-6860 KW - Time-dependent arrival rate KW - Multi-rate loss queue KW - Multi-rate network of loss queues KW - Blocking probability ER - TY - JOUR TI - Electronic Data Interchange: Research Review and Future Directions AU - Narayanan, Sriram AU - Marucheck, Ann S. AU - Handfield, Robert B. T2 - DECISION SCIENCES AB - ABSTRACT For nearly two decades, electronic data interchange (EDI) has been widely viewed as a technology pivotal to supply chain management that has also provided benefits to firms on multiple levels. Despite a substantial body of literature, there are a number of conflicting and inconclusive research results in this field. In this study, we synthesize the diverse body of research in EDI by organizing the literature into an initial theoretical framework. Based on a meta‐analysis of results from the empirical literature, we seek to clarify conflicting results from the literature in order to develop a more unified theoretical framework of contextual variables associated with EDI adoption factors and outcomes. From a managerial standpoint, our literature‐based framework offers a set of guidelines for making successful EDI adoption and implementation decisions. DA - 2009/2// PY - 2009/2// DO - 10.1111/j.1540-5915.2008.00218.x VL - 40 IS - 1 SP - 121-163 SN - 1540-5915 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-61849086828&partnerID=MN8TOARS KW - Electronic Data Interchange (EDI) KW - Electronic Linkages KW - Meta-Analysis KW - and Supply Chain Collaboration ER - TY - JOUR TI - Technical Note: A Computationally Efficient Algorithm for Undiscounted Markov Decision Processes with Restricted Observations AU - Davis, Lauren B. AU - Hodgson, Thom J. AU - King, Russell E. AU - Wei, Wenbin T2 - NAVAL RESEARCH LOGISTICS AB - Abstract We present a computationally efficient procedure to determine control policies for an infinite horizon Markov Decision process with restricted observations. The optimal policy for the system with restricted observations is a function of the observation process and not the unobservable states of the system. Thus, the policy is stationary with respect to the partitioned state space. The algorithm we propose addresses the undiscounted average cost case. The algorithm combines a local search with a modified version of Howard's (Dynamic programming and Markov processes, MIT Press, Cambridge, MA, 1960) policy iteration method. We demonstrate empirically that the algorithm finds the optimal deterministic policy for over 96% of the problem instances generated. For large scale problem instances, we demonstrate that the average cost associated with the local optimal policy is lower than the average cost associated with an integer rounded policy produced by the algorithm of Serin and Kulkarni Math Methods Oper Res 61 (2005) 311–328. © 2008 Wiley Periodicals, Inc. Naval Research Logistics 2009 DA - 2009/2// PY - 2009/2// DO - 10.1002/nav.20329 VL - 56 IS - 1 SP - 86-92 SN - 1520-6750 KW - Markov Decision process KW - heuristics KW - optimal control ER - TY - JOUR TI - Query optimization using restructured views: Theory and experiments AU - Chen, Dongfeng AU - Chirkova, Rada AU - Sadri, Fereidoon T2 - INFORMATION SYSTEMS AB - We study optimization of relational queries using materialized views, where views may be regular or restructured. In a restructured view, some data from the base table(s) are represented as metadata-that is, schema information, such as table and attribute names-or vice versa. Using restructured views in query optimization opens up a new spectrum of views that were not previously available, and can result in significant additional savings in query-evaluation costs. These savings can be obtained due to a significantly larger set of views to choose from, and may involve reduced table sizes, elimination of self-joins, clustering produced by restructuring, and horizontal partitioning. In this paper we propose a general query-optimization framework that treats regular and restructured views in a uniform manner and is applicable to SQL select-project-join queries and views without or with aggregation. Within the framework we provide (1) algorithms to determine when a view (regular or restructured) is usable in answering a query and (2) algorithms to rewrite queries using usable views. Semantic information, such as knowledge of the key of a view, can be used to further optimize a rewritten query. Within our general query-optimization framework, we develop techniques for determining the key of a (regular or restructured) view, and show how this information can be used to further optimize a rewritten query. It is straightforward to integrate all our algorithms and techniques into standard query-optimization algorithms. Our extensive experimental results illustrate how using restructured views (in addition to regular views) in query optimization can result in a significant reduction in query-processing costs compared to a system that uses only regular views. DA - 2009/5// PY - 2009/5// DO - 10.1016/j.is.2008.10.002 VL - 34 IS - 3 SP - 353-370 SN - 1873-6076 KW - Query optimization KW - Restructured views KW - Query optimization using materialized views ER - TY - JOUR TI - Optical burst switching AU - Murphy, J. AU - Perros, H. T2 - IET Communications DA - 2009/// PY - 2009/// VL - 3 IS - 3 SP - 331-333 ER - TY - JOUR TI - On the departure process of burst aggregation algorithms in optical burst switching AU - Mountrouidou, Xenia AU - Perros, Harry T2 - COMPUTER NETWORKS AB - We characterize analytically the departure process from the following three burst aggregation algorithms: the time based aggregation algorithm, the burst-length based aggregation algorithm and the time and burst-length based aggregation algorithm. The arrival process of packets is assumed to be Poisson or bursty modeled by an Interrupted Poisson Process (IPP). The analytic results are approximate and validation against simulation data showed that they have good accuracy. DA - 2009/2/27/ PY - 2009/2/27/ DO - 10.1016/j.comnet.2008.09.019 VL - 53 IS - 3 SP - 247-264 SN - 1872-7069 KW - Burst aggregation algorithms KW - Poisson process KW - Interrupted Poisson Process ER - TY - JOUR TI - Minimizing a linear fractional function subject to a system of sup-T equations with a continuous Archimedean triangular norm AU - Li, Pingke AU - Fang, Shu-Cherng T2 - JOURNAL OF SYSTEMS SCIENCE & COMPLEXITY DA - 2009/3// PY - 2009/3// DO - 10.1007/s11424-009-9146-x VL - 22 IS - 1 SP - 49-62 SN - 1559-7067 KW - Fractional optimization KW - fuzzy relational equations KW - triangular norms ER - TY - JOUR TI - ESTIMATION AND IDENTIFICATION OF PARAMETERS IN A LUMPED CEREBROVASCULAR MODEL AU - Pope, Scott R. AU - Ellwein, Laura M. AU - Zapata, Cheryl L. AU - Novak, Vera AU - Kelley, C. T. AU - Olufsen, Mette S. T2 - MATHEMATICAL BIOSCIENCES AND ENGINEERING AB - This study shows how sensitivity analysis and subset selection can be employed in a cardiovascular model to estimate total systemic resistance, cerebrovascular resistance, arterial compliance, and time for peak systolic ventricular pressure for healthy young and elderly subjects. These quantities are parameters in a simple lumped parameter model that predicts pressure and flow in the systemic circulation. The model is combined with experimental measurements of blood flow velocity from the middle cerebral artery and arterial finger blood pressure. To estimate the model parameters we use nonlinear optimization combined with sensitivity analysis and subset selection. Sensitivity analysis allows us to rank model parameters from the most to the least sensitive with respect to the output states (cerebral blood flow velocity and arterial blood pressure). Subset selection allows us to identify a set of independent candidate parameters that can be estimated given limited data. Analyses of output from both methods allow us to identify five independent sensitive parameters that can be estimated given the data. Results show that with the advance of age total systemic and cerebral resistances increase, that time for peak systolic ventricular pressure is increases, and that arterial compliance is reduced. Thus, the method discussed in this study provides a new methodology to extract clinical markers that cannot easily be assessed noninvasively. DA - 2009/1// PY - 2009/1// DO - 10.3934/mbe.2009.6.93 VL - 6 IS - 1 SP - 93-115 SN - 1551-0018 KW - cardiovascular modeling KW - systemic resistance KW - cerebrovascular resistance KW - parameter estimation KW - sensitivity analysis KW - subset selection ER - TY - JOUR TI - Denial of service attacks and defenses in decentralized trust management AU - Li, Jiangtao AU - Li, Ninghui AU - Wang, XiaoFeng AU - Yu, Ting T2 - INTERNATIONAL JOURNAL OF INFORMATION SECURITY AB - Trust management is an approach to scalable and flexible access control in decentralized systems. In trust management, a server often needs to evaluate a chain of credentials submitted by a client; this requires the server to perform multiple expensive digital signature verifications. In this paper, we study low-bandwidth Denial-of-Service (DoS) attacks that exploit the existence of trust management systems to deplete server resources. Although the threat of DoS attacks has been studied for some application-level protocols such as authentication protocols, we show that it is especially destructive for trust management systems. Exploiting the delegation feature in trust management languages, an attacker can forge a long credential chain to force a server to consume a large amount of computing resource. Using game theory as an analytic tool, we demonstrate that unprotected trust management servers will easily fall prey to a witty attacker who moves smartly. We report our empirical study of existing trust management systems, which manifests the gravity of this threat. We also propose a defense technique using credential caching, and show that it is effective in the presence of intelligent attackers. DA - 2009/4// PY - 2009/4// DO - 10.1007/s10207-008-0068-8 VL - 8 IS - 2 SP - 89-101 SN - 1615-5270 KW - Trust management KW - Denial of service KW - Access control KW - Trust negotiation KW - Game theory ER - TY - JOUR TI - Burst lost probabilities in a queuing network with simultaneous resource possession: a single-node decomposition approach AU - Battestilli, L. AU - Perros, H. AU - Chukova, S. T2 - IET COMMUNICATIONS AB - An efficient analytical method is presented for the calculation of blocking probabilities in a tandem queuing network with simultaneous resource possession. This queuing network model is motivated from the need to model optical burst switching networks, where the size of the data bursts varies and the link distance between two adjacent network elements also varies depending on the network's topology. A fast single-node decomposition algorithm is developed to compute the blocking probabilities in the network. The algorithm extends the popular link-decomposition method from teletraffic theory by allowing dynamic simultaneous link possession. Simulation is used to validate the accuracy of the algorithm. DA - 2009/3// PY - 2009/3// DO - 10.1049/iet-com:20070426 VL - 3 IS - 3 SP - 441-453 SN - 1751-8636 ER - TY - CONF TI - Analysis and computation for a fluid mixture model AU - Jiang, Q. L. AU - Li, Z. L. AU - Lubkin, S. R. C2 - 2009/// C3 - Communications in Computational Physics DA - 2009/// VL - 5 SP - 620-634 M1 - 2-4 ER - TY - JOUR TI - An organizational entrepreneurship model of supply management integration and performance outcomes AU - Handfield, R. AU - Petersen, K. AU - Cousins, P. AU - Lawson, B. T2 - International Journal of Operations & Production Management DA - 2009/// PY - 2009/// VL - 29 IS - 1-2 SP - 100-126 ER - TY - JOUR TI - A unified mobility model for analysis and simulation of mobile wireless networks AU - Zhao, Ming AU - Wang, Wenye T2 - WIRELESS NETWORKS DA - 2009/4// PY - 2009/4// DO - 10.1007/s11276-007-0055-4 VL - 15 IS - 3 SP - 365-389 SN - 1572-8196 KW - Mobility model KW - Smooth movement KW - Semi-Markov process KW - Stochastic analysis KW - Network performance evaluation KW - Mobile wireless networks ER - TY - JOUR TI - Stability criteria for differential-algebraic equations with multiple delays and their numerical solutions AU - Campbell, Stephen L. AU - Linh, Vu Hoang T2 - APPLIED MATHEMATICS AND COMPUTATION AB - This paper is concerned with the asymptotic stability of differential-algebraic equations with multiple delays and their numerical solutions. First, we give a sufficient condition for delay-independent stability. After characterizing the coefficient matrices that satisfy this stability condition, we propose some practical checkable criteria for asymptotic stability. Then we investigate the stability of numerical solutions obtained by θ-methods and BDF methods. Finally, solvability and stability of a class of weakly regular delay differential-algebraic equations are analyzed. DA - 2009/2/15/ PY - 2009/2/15/ DO - 10.1016/j.amc.2008.12.008 VL - 208 IS - 2 SP - 397-415 SN - 1873-5649 KW - Delay differential-algebraic equation KW - Multiple delays KW - Asymptotic stability KW - Regular pencil KW - Numerical solution ER - TY - JOUR TI - Modeling the effect of node synchronization times in ultra-wideband wireless networks AU - Taggart, Christopher S. AU - Viniotis, Yannis AU - Sichitiu, Mihail L. T2 - PERFORMANCE EVALUATION AB - Ultra-wideband wireless (UWB) can provide the physical layer for high-throughput personal area networks. When UWB is used for communication between many nodes, relatively long acquisition times are needed when dropping and re-establishing wireless links between the nodes. This paper describes the development and use of mathematical and simulation models to investigate the impact of dropping and reacquiring links between nodes on average packet delay; we also consider the performance of the alternative strategy of forwarding packets through intermediate nodes without breaking the established wireless links. The work presented here assumes that no specific MAC layer protocol, such as WiMedia UWB MAC, is in operation. The paper describes the models, explains the selection of modeling parameters used, compares the average packet delay for a network of three simple UWB nodes and for a ring of ten UWB nodes and explains the use of these results for network design engineers. DA - 2009/3// PY - 2009/3// DO - 10.1016/j.peva.2008.10.008 VL - 66 IS - 3-5 SP - 223-239 SN - 1872-745X KW - Ultra-wideband KW - Average delay KW - Simulation KW - Servers with vacations ER - TY - JOUR TI - Measuring and partitioning the high-order linkage disequilibrium by multiple order Markov chains (vol 32, pg 301, 2008) AU - Kim, Y. J. AU - Feng, S. AU - Zeng, Z. B. T2 - Genetic Epidemiology DA - 2009/// PY - 2009/// VL - 33 IS - 2 SP - 181-181 ER - TY - JOUR TI - Knowledge Sharing in Interorganizational Product Development Teams: The Effect of Formal and Informal Socialization Mechanisms AU - Lawson, Benn AU - Petersen, Kenneth J. AU - Cousins, Paul D. AU - Handfield, Robert B. T2 - JOURNAL OF PRODUCT INNOVATION MANAGEMENT AB - Working collaboratively with suppliers is increasingly cited as a “best practice” in product development. The importance of sharing knowledge between buyer and supplier in this context has been well recognized, although comparatively little research exists on the interorganizational socialization mechanisms that facilitate it. The present research proposes and tests a theoretical model of the impact of formal and informal socialization mechanisms on the level of knowledge sharing within interorganizational product development projects and the subsequent effect on buyer firm performance. Results from this study of 111 manufacturing organizations in the United Kingdom largely support its hypotheses. It is revealed that informal socialization mechanisms (e.g., communication guidelines, social events) play an important role in facilitating interorganizational knowledge sharing, whereas formal socialization mechanisms (e.g., cross‐functional teams, matrix reporting structures) act indirectly through informal socialization to influence knowledge sharing. The results also show that interorganizational knowledge sharing is positively associated with supplier contribution to development outcomes, which, in turn, improves buyer product development performance and, ultimately, financial performance. Product development managers are encouraged to build social ties between interorganizational development teams to increase the flow of knowledge and to improve both product development outcomes and financial performance. DA - 2009/3// PY - 2009/3// DO - 10.1111/j.1540-5885.2009.00343.x VL - 26 IS - 2 SP - 156-172 SN - 0737-6782 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-59349107272&partnerID=MN8TOARS ER - TY - JOUR TI - Identification of protein-coding sequences using the hybridization of 18S rRNA and mRNA during translation AU - Xing, Chuanhua AU - Bitzer, Donald L. AU - Alexander, Winser E. AU - Vouk, Mladen A. AU - Stomp, Anne-Marie T2 - NUCLEIC ACIDS RESEARCH AB - We introduce a new approach in this article to distinguish protein-coding sequences from non-coding sequences utilizing a period-3, free energy signal that arises from the interactions of the 3′-terminal nucleotides of the 18S rRNA with mRNA. We extracted the special features of the amplitude and the phase of the period-3 signal in protein-coding regions, which is not found in non-coding regions, and used them to distinguish protein-coding sequences from non-coding sequences. We tested on all the experimental genes from Saccharomyces cerevisiae and Schizosaccharomyces pombe . The identification was consistent with the corresponding information from GenBank, and produced better performance compared to existing methods that use a period-3 signal. The primary tests on some fly, mouse and human genes suggests that our method is applicable to higher eukaryotic genes. The tests on pseudogenes indicated that most pseudogenes have no period-3 signal. Some exploration of the 3′-tail of 18S rRNA and pattern analysis of protein-coding sequences supported further our assumption that the 3′-tail of 18S rRNA has a role of synchronization throughout translation elongation process. This, in turn, can be utilized for the identification of protein-coding sequences. DA - 2009/2// PY - 2009/2// DO - 10.1093/nar/gkn917 VL - 37 IS - 2 SP - 591-601 SN - 1362-4962 ER - TY - JOUR TI - Combining Trust-Region Techniques and Rosenbrock Methods to Compute Stationary Points AU - Luo, X. -L. AU - Kelley, C. T. AU - Liao, L. -Z. AU - Tam, H. W. T2 - JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS AB - Rosenbrock methods are popular for solving a stiff initial-value problem of ordinary differential equations. One advantage is that there is no need to solve a nonlinear equation at every iteration, as compared with other implicit methods such as backward difference formulas or implicit Runge–Kutta methods. In this article, we introduce a trust-region technique to select the time steps of a second-order Rosenbrock method for a special initial-value problem, namely, a gradient system obtained from an unconstrained optimization problem. The technique is different from the local error approach. Both local and global convergence properties of the new method for solving an equilibrium point of the gradient system are addressed. Finally, some promising numerical results are also presented. DA - 2009/2// PY - 2009/2// DO - 10.1007/s10957-008-9469-0 VL - 140 IS - 2 SP - 265-286 SN - 1573-2878 KW - Trust-region methods KW - Unconstrained optimization KW - Rosenbrock method KW - Gradient system KW - Ordinary differential equations ER - TY - JOUR TI - Adaptive techniques for the MRAC, adaptive parameter identification, and on-line fault monitoring and accommodation for a class of positive real infinite dimensional systems AU - Demetriou, Michael A. AU - Ito, Kazufumi AU - Smith, Ralph C. T2 - INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING AB - Abstract A theoretical framework of the model reference adaptive control design, adaptive parameter identification and automated fault detection is developed for a class of positive real infinite dimensional systems. Uncertain terms are treated as additive perturbations of the plant operator and the framework provides a unified treatment for model reference control, parameter estimation and fault detection and accommodation. For each design problem the well‐posedness and stability of the proposed adaptive scheme are investigated. Extensions to the variable structure observer, to specific forms of the structured perturbation terms and to slowly time‐varying systems are also considered within the proposed framework. Such results are summarized as they capitalize on the proposed well‐posedness and stability results for the general cases. Copyright © 2008 John Wiley & Sons, Ltd. DA - 2009/2// PY - 2009/2// DO - 10.1002/acs.1058 VL - 23 IS - 2 SP - 193-215 SN - 1099-1115 KW - positive real KW - structured perturbations KW - infinite dimensional systems KW - adaptive observers KW - MRAC KW - fault detection and accommodation ER - TY - JOUR TI - A Joint Association Test for Multiple SNPs in Genetic Case-Control Studies AU - Wang, Tao AU - Jacob, Howard AU - Ghosh, Soumitra AU - Wang, Xujing AU - Zeng, Zhao-Bang T2 - GENETIC EPIDEMIOLOGY AB - For a dense set of genetic markers such as single nucleotide polymorphisms (SNPs) on high linkage disequilibrium within a small candidate region, a haplotype-based approach for testing association between a disease phenotype and the set of markers is attractive in reducing the data complexity and increasing the statistical power. However, due to unknown status of the underlying disease variant, a comprehensive association test may require consideration of various combinations of the SNPs, which often leads to severe multiple testing problems. In this paper, we propose a latent variable approach to test for association of multiple tightly linked SNPs in case-control studies. First, we introduce a latent variable into the penetrance model to characterize a putative disease susceptible locus (DSL) that may consist of a marker allele, a haplotype from a subset of the markers, or an allele at a putative locus between the markers. Next, through using of a retrospective likelihood to adjust for the case-control sampling ascertainment and appropriately handle the Hardy-Weinberg equilibrium constraint, we develop an expectation-maximization (EM)-based algorithm to fit the penetrance model and estimate the joint haplotype frequencies of the DSL and markers simultaneously. With the latent variable to describe a flexible role of the DSL, the likelihood ratio statistic can then provide a joint association test for the set of markers without requiring an adjustment for testing of multiple haplotypes. Our simulation results also reveal that the latent variable approach may have improved power under certain scenarios comparing with classical haplotype association methods. DA - 2009/2// PY - 2009/2// DO - 10.1002/gepi.20368 VL - 33 IS - 2 SP - 151-163 SN - 0741-0395 KW - haplotype association KW - retrospective likelihood KW - latent variable KW - logistic mixture model KW - EM algorithm ER - TY - JOUR TI - Disturbance attenuation by output feedback for linear systems subject to actuator saturation AU - Wu, Fen AU - Zheng, Qian AU - Lin, Zongli T2 - INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL AB - Abstract In this paper, we study the problem of disturbance attenuation by output feedback for linear systems subject to actuator saturation. A nonlinear output feedback, expressed in the form of a quasi‐linear parameter‐varying system with state‐dependent scheduling parameter, is constructed that leads to the attenuation of the effect of the disturbance on the output of the system. The level of disturbance attenuation is measured in terms of the restricted ℒ︁ 2 gain and the restricted ℒ︁ 2 –ℒ︁ ∞ gain over a class of bounded disturbances. Copyright © 2008 John Wiley & Sons, Ltd. DA - 2009/1/25/ PY - 2009/1/25/ DO - 10.1002/rnc.1306 VL - 19 IS - 2 SP - 168-184 SN - 1099-1239 KW - nonlinear control KW - output feedback KW - disturbance rejection KW - actuator saturation KW - L-2 gain KW - L-2-L-infinity gain ER - TY - JOUR TI - Absolute Protein Quantification by LC/MSE for Global Analysis of Salicylic Acid-induced Plant Protein Secretion Responses AU - Cheng, Fang-yi AU - Blackburn, Kevin AU - Lin, Yu-min AU - Goshe, Michael B. AU - Williamson, John D. T2 - JOURNAL OF PROTEOME RESEARCH AB - The plant cell wall is a dynamic cellular compartment consisting of a complex matrix of components that can change dramatically in response to environmental stresses. During pathogen attack, for instance, a wide spectrum of proteins that participate in various sequential processes involved in plant defense is secreted into the cell wall. In this study, a mass spectrometry, data-independent acquisition approach known as LC/MS (E) was used to assess temporal changes in the cell wall proteome in response to different levels of an endogenous inducer of plant disease defense responses, salicylic acid (SA). LC/MS (E) was used as a label-free method that enabled simultaneous protein identification and absolute femtomole quantification of each protein secreted into the extracellular matrix. A total of 74 secreted proteins were identified, 63 of which showed increased specific secretion in response to SA. A majority of this induced secretion occurred within 2 h of treatment, indicating that many proteins are involved in the early stages of plant defenses. We also identified a number of apparently nonclassically secreted proteins, suggesting that, as in many nonplant systems, Golgi/ER-independent mechanisms exist for plant protein secretion. These results provide new insight into plant apoplastic defense mechanisms and demonstrate that LC/MS (E) is a powerful tool for obtaining both relative and absolute proteome-scale quantification that can be applied to complex, time- and dose-dependent experimental designs. DA - 2009/1// PY - 2009/1// DO - 10.1021/pr800649s VL - 8 IS - 1 SP - 82-93 SN - 1535-3907 KW - Arabidopsis KW - secretome KW - liquid chromatography KW - mass spectrometry KW - MSE KW - data-independent acquisition KW - salicylic acid KW - pathogen KW - nonclassical protein secretion ER - TY - JOUR TI - The impact of supply chain complexity on manufacturing plant performance AU - Bozarth, Cecil C. AU - Warsing, Donald P. AU - Flynn, Barbara B. AU - Flynn, E. James T2 - JOURNAL OF OPERATIONS MANAGEMENT AB - Abstract This paper puts forth a model of supply chain complexity and empirically tests it using plant‐level data from 209 plants across seven countries. The results show that upstream complexity, internal manufacturing complexity, and downstream complexity all have a negative impact on manufacturing plant performance. Furthermore, supply chain characteristics that drive dynamic complexity are shown to have a greater impact on performance than those that drive only detail complexity. In addition to providing a definition and empirical test of supply chain complexity, the study serves to link the systems complexity literature to the prescriptions found in the flexibility and lean production literatures. Finally, this research establishes a base from which to extend previous work linking operations strategy to organization design [Flynn, B.B., Flynn, E.J., 1999. Information‐processing alternatives for coping with manufacturing environment complexity. Decision Sciences 30 (4), 1021–1052]. DA - 2009/1// PY - 2009/1// DO - 10.1016/j.jom.2008.07.003 VL - 27 IS - 1 SP - 78-93 SN - 1873-1317 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-57649108561&partnerID=MN8TOARS KW - Supply chain complexity KW - Supply chain management KW - Manufacturing strategy KW - Supply management KW - Empirical research methods ER - TY - JOUR TI - On a semi-smooth Newton method and its globalization AU - Ito, Kazufumi AU - Kunisch, Karl T2 - MATHEMATICAL PROGRAMMING AB - This paper addresses the globalization of the semi-smooth Newton method for non-smooth equations F(x) = 0 in $${\mathbb{R}}^m$$ with applications to complementarity and discretized ℓ1-regularization problems. Assuming semi-smoothness it is shown that super-linearly convergent Newton methods can be globalized, if appropriate descent directions are used for the merit function |F(x)|2. Special attention is paid to directions obtained from the primal-dual active set strategy. DA - 2009/5// PY - 2009/5// DO - 10.1007/s10107-007-0196-3 VL - 118 IS - 2 SP - 347-370 SN - 1436-4646 ER - TY - JOUR TI - Achieving energy conservation in Poisson-Boltzmann molecular dynamics: Accuracy and precision with finite-difference algorithms AU - Wang, Jun AU - Cai, Qin AU - Li, Zhi-Lin AU - Zhao, Hong-Kai AU - Luo, Ray T2 - CHEMICAL PHYSICS LETTERS AB - Violation of energy conservation in Poisson-Boltzmann molecular dynamics, due to the limited accuracy and precision of numerical methods, is a major bottleneck preventing its wide adoption in biomolecular simulations. We explored the ideas of enforcing interface conditions by the immerse interface method and of removing charge singularity to improve the finite-difference methods. Our analysis of these ideas on an analytical test system shows significant improvement in both energies and forces. Our analysis further indicates the need for more accurate force calculation, especially the boundary force calculation. DA - 2009/1/22/ PY - 2009/1/22/ DO - 10.1016/j.cplett.2008.12.049 VL - 468 IS - 4-6 SP - 112-118 SN - 1873-4448 ER - TY - JOUR TI - Convergence properties of sequential Bayesian D-optimal designs AU - Roy, Anindya AU - Ghosal, Subhashis AU - Rosenberger, William F. T2 - JOURNAL OF STATISTICAL PLANNING AND INFERENCE AB - We establish convergence properties of sequential Bayesian optimal designs. In particular, for sequential D-optimality under a general nonlinear location-scale model for binary experiments, we establish posterior consistency, consistency of the design measure, and the asymptotic normality of posterior following the design. We illustrate our results in the context of a particular application in the design of phase I clinical trials, namely a sequential design of Haines et al. [2003. Bayesian optimal designs for phase I clinical trials. Biometrics 59, 591--600] that incorporates an ethical constraint on overdosing. DA - 2009/2/1/ PY - 2009/2/1/ DO - 10.1016/j.jspi.2008.04.025 VL - 139 IS - 2 SP - 425-440 SN - 1873-1171 KW - Adaptive designs KW - Asymptotic normality KW - Discrete optimal design KW - Dose-response KW - Posterior convergence ER - TY - JOUR TI - Optimal piecewise-constant signal design for active fault detection AU - Choe, D. AU - Campbell, S. L. AU - Nikoukhah, R. T2 - INTERNATIONAL JOURNAL OF CONTROL AB - Recently there has been an increasing interest in active fault detection when traditional approaches are not effective or cannot be used. Previous papers have shown how to construct continuously varying test (auxiliary) signals for use in fault detection and identification. Such signals may not always be easy to implement. In this paper a new algorithm is presented to compute optimal piecewise constant test signals. In the important case where the test signal changes values a small number of times, the new test signals can be both smaller and more effective than test signals computed by other means. Two computational examples are given to illustrate both computational issues and differences between different types of piecewise constant signals. DA - 2009/// PY - 2009/// DO - 10.1080/00207170801993587 VL - 82 IS - 1 SP - 130-146 SN - 1366-5820 KW - fault detection KW - active KW - test signal KW - optimisation ER - TY - JOUR TI - Area variance estimators for simulation using folded standardized time series AU - Antonini, Claudia AU - Alexopoulos, Christos AU - Goldsman, David AU - Wilson, James R. T2 - IIE TRANSACTIONS AB - We estimate the variance parameter of a stationary simulation-generated process using “folded” versions of standardized time series area estimators. Asymptotically as the sample size increases, different folding levels yield unbiased estimators that are independent scaled chi-squared variates, each with one degree of freedom. This result is exploited to formulate improved variance estimators based on the combination of multiple levels as well as the use of batching. The improved estimators preserve the asymptotic bias properties of their predecessors, but have substantially lower asymptotic variances. The performance of the new variance estimators is demonstrated in a first-order autoregressive process with autoregressive parameter 0.9 and in the queue-waiting-time process for an M/M/1 queue with server utilization 0.8. [Supplementary materials are available for this article. Go to the publisher's online edition of IIE Transactions for the following free supplemental resource: Appendix] DA - 2009/// PY - 2009/// DO - 10.1080/07408170802331268 VL - 41 IS - 2 SP - 134-144 SN - 1545-8830 KW - Steady-state simulation KW - simulation output analysis methods KW - method of standardized time series KW - batching KW - variance estimation ER -