TY - JOUR TI - A multi-criteria decision making model for outsourcing inbound logistics of an automotive industry using the AHP and TOPSIS AU - Ramkumar, N. AU - Subramanian, P. AU - Rajmohan, M. T2 - International Journal of Enterprise Network Management AB - This paper focuses on the inbound logistics segment in the supply chain of automobile companies, which are known to be highly complex. This has always affected key business functions in the supply chain with respect to cost, coordination, and material delay issues. During third party logistics service provider (TPLs) selection, practitioners have started to concentrate on coordination, integration, and cooperation as some of the key areas to improve SC performance. In this context, we propose a model for selection of TPLs network with an objective to create a favourable environment for improving coordination and integration using analytic hierarchy process (AHP) and technique for order preference by similarity to ideal situation (TOPSIS) approach. A case of an automobile company is used to explain the model and potential expected benefits are discussed. A comparative analysis on decision-making certainty between the classical AHP and TOPSIS approach is also discussed. DA - 2009/// PY - 2009/// DO - 10.1504/ijenm.2009.032396 VL - 3 IS - 3 SP - 223 J2 - IJENM LA - en OP - SN - 1748-1252 1748-1260 UR - http://dx.doi.org/10.1504/ijenm.2009.032396 DB - Crossref ER - TY - CONF TI - Mathematical model for Multi-Echelon, Multi-Product, Single Time-Period Closed Loop Supply Chain AU - Subramanian, P AU - Ramkumar, N AU - Narendran, T.T. C2 - 2009/// C3 - XIII Annual International Conference of Society of Operations Management, IIT Madras DA - 2009/// ER - TY - JOUR TI - Compression Adjustable Fabric and Garments AU - Reid Jr, Lawrence G AU - Grant, Edward AU - Hegarty, Meghan Sarah AU - Livingston, Frederick DA - 2009/9// PY - 2009/9// N1 - US Patent App. 12/402,646 RN - US Patent App. 12/402,646 ER - TY - JOUR TI - Health Monitoring and Management System AU - Reid Jr, Lawrence G AU - Grant, Edward AU - Hegarty, Meghan Sarah AU - Livingston, Frederick DA - 2009/9// PY - 2009/9// N1 - US Patent App. 12/402,623 RN - US Patent App. 12/402,623 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 - Women match men when learning a spatial skill. AU - Spence, Ian AU - Yu, Jingjie Jessica AU - Feng, Jing AU - Marshman, Jeff T2 - Journal of Experimental Psychology: Learning, Memory, and Cognition AB - Meta-analytic studies have concluded that although training improves spatial cognition in both sexes, the male advantage generally persists. However, because some studies run counter to this pattern, a closer examination of the anomaly is warranted. The authors investigated the acquisition of a basic skill (spatial selective attention) using a matched-pair two-wave longitudinal design. Participants were screened with the use of an attentional visual field task, with the objective of selecting and matching 10 male-female pairs, over a wide range (30% to 57% correct). Subsequently, 20 participants 17-23 years of age (selected from 43 screened) were trained for 10 hr (distributed over several sessions) by playing a first-person shooter video game. This genre is known to be highly effective in enhancing spatial skills. All 20 participants improved, with matched members of the male-female pairs achieving very similar gains, independent of starting level. This is consistent with the hypothesis that the learning trajectory of women is not inferior to that of men when acquiring a basic spatial skill. Training methods that develop basic spatial skills may be essential to achieve gender parity in both basic and complex spatial tasks. DA - 2009/// PY - 2009/// DO - 10.1037/a0015641 VL - 35 IS - 4 SP - 1097-1103 J2 - Journal of Experimental Psychology: Learning, Memory, and Cognition LA - en OP - SN - 1939-1285 0278-7393 UR - http://dx.doi.org/10.1037/a0015641 DB - Crossref KW - spatial cognition KW - attentional visual field KW - gender differences KW - video game training KW - learning trajectory ER - TY - JOUR TI - The technology profile inventory: Construction, validation, and application AU - Spence, Ian AU - DeYoung, Colin G. AU - Feng, Jing T2 - Computers in Human Behavior AB - The technology profile inventory (TPI) measures attitudes toward computers and the internet. We describe the most recent phase of the construction of the TPI. The studies reported refine and validate the instrument, and we present the final version as an Appendix A. Using a new sample of respondents (N=394), we replicated the three major factors found previously (Confidence, Approval, and Interest). The TPI scores were related to patterns of information technology (IT) usage and also to gender. To demonstrate the practical utility of the TPI we report (1) results linking TPI scores to behavior during an internet search task; (2) test-retest results obtained as part of a cognitive training experiment using action video games; and (3) results showing that attitudes to IT may be modified by a particular experience with information technology. DA - 2009/3// PY - 2009/3// DO - 10.1016/j.chb.2008.10.009 VL - 25 IS - 2 SP - 458-465 J2 - Computers in Human Behavior LA - en OP - SN - 0747-5632 UR - http://dx.doi.org/10.1016/j.chb.2008.10.009 DB - Crossref KW - Attitudes KW - Information technology KW - IT KW - Human-computer interaction KW - HCI KW - Gender KW - Action video games ER - TY - CONF TI - Humanitarian Supply Chain Management - An Overview AU - Ergun, O. AU - Karakus, G. AU - Keskinocak, P. AU - Swann, J. AU - Villarreal, M. A2 - Barnhart, C. A2 - Clausen, U. A2 - Lauther, U. A2 - Mohring, R.H. C2 - 2009/// C3 - Models and Algorithms for Optimization in Logistics DA - 2009/// PB - Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik ER - TY - JOUR TI - Usability of the P300 Speller: Towards a More Sustainable Brain-Computer Interface AU - Nam, C.S. AU - Jeon, Y. AU - Li, Y. AU - Kim, Y.-J. AU - Yoon, H. T2 - eMinds: International Journal on Human-Computer Interaction DA - 2009/// PY - 2009/// VL - 1 IS - 5 SP - 111–125 ER - TY - JOUR TI - Evaluating emergency medical service performance measures AU - McLay, Laura A. AU - Mayorga, Maria E. T2 - Health Care Management Science DA - 2009/8/25/ PY - 2009/8/25/ DO - 10.1007/s10729-009-9115-x VL - 13 IS - 2 SP - 124-136 J2 - Health Care Manag Sci LA - en OP - SN - 1386-9620 1572-9389 UR - http://dx.doi.org/10.1007/s10729-009-9115-x DB - Crossref KW - Discrete optimization KW - Emergency medical service KW - Patient outcomes KW - Performance measures KW - Health policy modeling ER - TY - JOUR TI - Quantifying the Impact of Variability and Noise on Patient Outcomes in Breast Cancer Decision Making AU - Simmons Ivy, Julie AU - Black Nembhard, Harriet AU - Baran, Kimberly T2 - Quality Engineering AB - ABSTRACT There are many factors that can affect the breast cancer decision-making process. This article addresses issues of uncertainty. Specifically, we seek to answer two questions: (1) What are the major contributors to false positive test results for patients? (2) How does variability between different radiologists affect outcomes for patients? We develop a simulation-based model that combines statistical process control (SPC) with a partially observable Markov decision process (POMDP) to incorporate uncertainty, the inherent variability between radiologists, and system noise (i.e., screening characteristics such as different densities of breast tissue, inherent variability between different women, and imperfections in the mammogram and technology) to determine the impact on the breast cancer monitoring decision. When compared to population-based noise, we find that the variability among different radiologists in the ability to correctly interpret a mammogram has the most significant impact on whether a woman will receive incorrect results. Variability within the population of radiologists significantly increases in the number of false-positive mammogram results a woman receives. This suggests that reducing the variability between radiologists should be a primary concern to improve health care for women. DA - 2009/6/12/ PY - 2009/6/12/ DO - 10.1080/08982110902762634 VL - 21 IS - 3 SP - 319-334 J2 - Quality Engineering LA - en OP - SN - 0898-2112 1532-4222 UR - http://dx.doi.org/10.1080/08982110902762634 DB - Crossref 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 - CHAP TI - Haptic Science Learning System for Students with Visual Impairments: A Preliminary Study AU - Yamaguchi, Takehiko AU - Johnson, Steve AU - Kim, Hyung Nam AU - Li, Yueqing AU - Nam, Chang S. AU - Smith-Jackson, Tonya L. T2 - Lecture Notes in Computer Science AB - This paper assesses the usability of developed haptic interface features to support future development of haptically enhanced science learning applications for students with visual impairments. Of the features developed and evaluated, three features are described in this study: Haptic Boundary, Menu Selection, and Object Recognition. Two focus groups participated in an interview and usability session. Results from this study give insight to the needs of the visually impaired community in regard to haptic applications. PY - 2009/// DO - 10.1007/978-3-642-02713-0_17 SP - 157-166 OP - PB - Springer Berlin Heidelberg SN - 9783642027123 9783642027130 UR - http://dx.doi.org/10.1007/978-3-642-02713-0_17 DB - Crossref ER - TY - JOUR TI - A stochastic model for the optimal batch size in multi-step operations with process and product variability AU - Shin, D. AU - Park, J. AU - Kim, N. AU - Wysk, R.A. T2 - International Journal of Production Research AB - Virtually all manufacturing processes are subject to variability, an inherent characteristic of most production processes. No two parts can ever be exactly the same in terms of their dimensions. For machining processes such as drilling, milling, and lathing, overall variability is caused in part by machine tools, tooling, fixtures and workpiece material. Since variability, which can be accumulated from tolerance stacking, can result in defective parts the number of parts produced in a batch is limited. When there are too many parts in a batch, the likelihood of producing all acceptable parts in a batch decreases due to the increased tolerances. On the other hand, too small a batch size incurs an increase of manufacturing costs due to frequent setups and tool replacements, whereas the likelihood of acceptable parts increases. To address this challenge, we present a stochastic model for determining the optimal batch size where we consider part-to-part variation in terms of tool wear, which tends to be propo... DA - 2009/5/13/ PY - 2009/5/13/ DO - 10.1080/00207540701810778 VL - 47 IS - 14 SP - 3919-3936 J2 - International Journal of Production Research LA - en OP - SN - 0020-7543 1366-588X UR - http://dx.doi.org/10.1080/00207540701810778 DB - Crossref KW - process variability KW - batch size KW - tolerance stacking KW - stochastic deviation ER - TY - JOUR TI - Experimental investigation of the machining induced residual stress tensor under mechanical loading AU - Fu, Wei-En AU - Cohen, Paul H. AU - Ruud, Clayton O. T2 - Journal of Manufacturing Processes AB - Residual stress induced by machining is complex and difficult to predict, since it involves mechanical loads, temperature gradients or phase transformation in the generation mechanism. In this work, an experiment with a statistical design for the residual stress tensor was performed to investigate the residual stress profile on a machined surface. In order to understand the generation mechanism of residual stress in machining, three variables and workpiece materials were carefully selected to focus on the mechanical loads and avoid the temperature gradients and phase transformation on the machined surface. The mechanical loads considered here included the chip formation force at the primary shear zone and the plowing force at the tool tip–workpiece contact. Depths of cut and rake angles were selected to alter the chip formation force, and the tool tip radius was designed to emphasize the plowing effect. The workpiece material was aluminum 3003. The experimental results showed that the chip formation force provides basic shapes of the residual stress profile for a machined surface. It decides the depth of the peak residual stress below the surface. However, the plowing force was the dominating effect on the surface residual stress, causing high stresses on the surface. The plowing force can shift the surface stress from tensile to compressive. Additionally, the measured stress tensor proved that in-plane shear stress exists for the machined surface. DA - 2009/7// PY - 2009/7// DO - 10.1016/j.jmapro.2009.11.001 VL - 11 IS - 2 SP - 88-96 J2 - Journal of Manufacturing Processes LA - en OP - SN - 1526-6125 UR - http://dx.doi.org/10.1016/j.jmapro.2009.11.001 DB - Crossref 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 - CHAP TI - Incorporating Environmental Concerns in Supply Chain Optimization AU - Mayorga, Maria E. AU - Subramanian, Ravi T2 - Environmentally Conscious Materials Handling AB - This chapter contains sections titled: Introduction Legislative Factors Economic Factors Social Factors Approaches to Optimization Summary References PY - 2009/7/27/ DO - 10.1002/9780470432730.ch4 SP - 117-135 OP - PB - John Wiley & Sons, Inc. SN - 9780470432730 9780470170700 UR - http://dx.doi.org/10.1002/9780470432730.ch4 DB - Crossref ER - TY - JOUR TI - Allocating flexible servers in serial systems with switching costs AU - Mayorga, Maria E. AU - Taaffe, Kevin M. AU - Arumugam, Ramesh T2 - Annals of Operations Research DA - 2009/5/27/ PY - 2009/5/27/ DO - 10.1007/s10479-009-0575-7 VL - 172 IS - 1 SP - 231-242 J2 - Ann Oper Res LA - en OP - SN - 0254-5330 1572-9338 UR - http://dx.doi.org/10.1007/s10479-009-0575-7 DB - Crossref ER - TY - JOUR TI - Incorporating affective customer needs for luxuriousness into product design attributes AU - Bahn, Sangwoo AU - Lee, Cheol AU - Nam, Chang S. AU - Yun, Myung Hwan T2 - Human Factors and Ergonomics in Manufacturing AB - Abstract In a highly competitive market, customers' product affection is a critical factor to product success. However, understanding customers' affective needs is difficult to grasp; product design practitioners often misunderstand what customers really want. In this study we report our experience in developing and using an affective design framework that identified critical affective features customers have on products and are systematically incorporated into product design attributes. To identify key affective features such as luxuriousness, we utilized the Kansei engineering methodology. This approach consists of three steps: (1) selecting related affective features and product design attributes through a comprehensive literature survey, expert panel opinion, and focus group interviews; (2) conducting evaluation experiments; and (3) developing Kansei models using multivariate statistical analysis and analyzing critical product design attributes. To demonstrate applicability of the proposed affective design framework, 30 customers and 30 product design practitioners participated in an evaluation experiment for car crash pads, and 44 customers and 20 designers participated in an evaluation experiment for two interior room products (wallpapers and flooring materials). The evaluation experiments were conducted via systematically developed questionnaires consisting of a 7‐point semantic differential scale and a 100‐point magnitude estimation scale. The results of the experiments were analyzed using principal component regression and quantification theory type I method. Using the analyzed survey data, the relationship between luxuriousness and related affective features and product design attributes were identified. This relationship indicated that there was a significant difference in the perception of luxuriousness between customers and designers. Consequently, it is expected that the results of this study could provide a foundation for developing affective products. © 2009 Wiley Periodicals, Inc. DA - 2009/3// PY - 2009/3// DO - 10.1002/hfm.20140 VL - 19 IS - 2 SP - 105-127 J2 - Hum. Factors Man. LA - en OP - SN - 1090-8471 1520-6564 UR - http://dx.doi.org/10.1002/hfm.20140 DB - Crossref ER - TY - JOUR TI - Evaluation of human–agent user interfaces in multi-agent systems AU - Nam, Chang S. AU - Johnson, Steve AU - Li, Yueqing AU - Seong, Younho T2 - International Journal of Industrial Ergonomics AB - A multi-agent system (MAS) is a computational system in which two or more intelligent agents work together to perform a set of tasks. MAS's have had a significant impact in a wide range of applications. However, little attention has been paid to the design of human–agent user interfaces. Our research was conducted primarily to further explore interaction between humans and intelligent agents, as well as attempt to solidify foundational concepts for intelligent multi-agent system interface design. Based on the foundation of the commercialized PC game Unreal Tournament 2003, a framework was developed that utilized fundamental interface design principles as well as newly designed guidelines. Three user interfaces were designed for an experiment conducted with 25 participants. Their performances were evaluated via effectiveness, efficiency, satisfaction, and workload metrics. Through the testing of scenario tasks, an in-depth study was conducted on the collaboration between the human user and intelligent agents within a system. Finally, the paper summarized a set of design principles and guidelines developed through the study, which could easily be applicable to the design of future user interfaces for multi-agent systems. A deeper understanding of the manner by which the appropriate information is provided to the user interacting with multi-agent systems in the correct form at the right time should have a broad impact on the future development of intelligent multi-agent system interfaces. DA - 2009/1// PY - 2009/1// DO - 10.1016/j.ergon.2008.08.008 VL - 39 IS - 1 SP - 192-201 J2 - International Journal of Industrial Ergonomics LA - en OP - SN - 0169-8141 UR - http://dx.doi.org/10.1016/j.ergon.2008.08.008 DB - Crossref KW - Human-agent user interface KW - Multi-agent system KW - Usability evaluation KW - Human factors ER - TY - JOUR TI - The process of team communication in multi-cultural contexts: An empirical study using Bales’ interaction process analysis (IPA) AU - Nam, Chang S. AU - Lyons, Joseph B. AU - Hwang, Ha-Sung AU - Kim, Sukwon T2 - International Journal of Industrial Ergonomics AB - The main goal of the present study was to empirically investigate the manner in which cultural diversity and communication mode affect team communication process. Two independent variables were manipulated in the study: (1) cultural diversity (homogeneous versus heterogeneous); and (2) communication mode (face-to-face versus computer-mediated communication). Team members’ communication exchanges were measured by using Bales’ interaction process analysis (IPA) that divides the function (as opposed to the topical content) of communication during group discussion into either task-related or socio-emotional contributions at two-levels: communication profile and functional area. Results of this study indicated homogeneous teams used more showing agreement, giving opinions, and showing tension communication patterns compared to heterogeneous teams. Additionally, when considering the higher-level functional areas, teams using face-to-face (FTF) communication strategies were characterized by greater positive socio-emotional communication, more attempted answers, more questions, and more frequent negative socio-emotional communications. The results of the present study also suggested that the impact of communication mode on team communication varies by the level of diversity within the team. The outcomes of this research should have a broad impact on the management of a multi-cultural team, a task-oriented team consisting of people with different national cultures. Relevance to industry: Results of the present study should provide valuable insights into the ways in which cultural diversity and communication mode influence the communication mechanisms which take place among members during team interaction. DA - 2009/9// PY - 2009/9// DO - 10.1016/j.ergon.2009.03.004 VL - 39 IS - 5 SP - 771-782 J2 - International Journal of Industrial Ergonomics LA - en OP - SN - 0169-8141 UR - http://dx.doi.org/10.1016/j.ergon.2009.03.004 DB - Crossref KW - Team communication KW - Bales' interaction process analysis (IPA) KW - Cultural ergonomics KW - Team decision-making ER - TY - JOUR TI - Supporting Collaborative Privacy-Observant Information Sharing Using RFID-Tagged Objects AU - Konomi, Shin'ichi AU - Nam, Chang S. T2 - Advances in Human-Computer Interaction AB - RFID technology provides an economically feasible means to embed computing and communication capabilities in numerous physical objects around us, thereby allowing anyone to effortlessly announce and expose varieties of information anywhere at any time. As the technology is increasingly used in everyday environments, there is a heightening tension in the design and shaping of social boundaries in the digitally enhanced real world. Our experiments of RFID-triggered information sharing have identified usability, deployment, and privacy issues of physically based information systems. We discuss awareness issues and cognitive costs in regulating RFID-triggered information flows and propose a framework for privacy-observant RFID applications. The proposed framework supports users' in situ privacy boundary control by allowing users to (1) see how their information is socially disclosed and viewed by others, (2) dynamically negotiate their privacy boundaries, and (3) automate certain information disclosure processes. DA - 2009/// PY - 2009/// DO - 10.1155/2009/713516 VL - 2009 SP - 1-13 J2 - Advances in Human-Computer Interaction LA - en OP - SN - 1687-5893 1687-5907 UR - http://dx.doi.org/10.1155/2009/713516 DB - Crossref 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 - 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 - Real time in vitro measurement of oxygen uptake rates for HEPG2 liver cells encapsulated in alginate matrices AU - Mishra, Anuja AU - Starly, Binil T2 - Microfluidics and Nanofluidics DA - 2009/1/23/ PY - 2009/1/23/ DO - 10.1007/s10404-008-0396-z VL - 6 IS - 3 SP - 373-381 J2 - Microfluid Nanofluid LA - en OP - SN - 1613-4982 1613-4990 UR - http://dx.doi.org/10.1007/s10404-008-0396-z DB - Crossref KW - Oxygen uptake rate (OUR) KW - Fiber optic sensor KW - Alginate KW - HEPG2 liver cells ER - TY - JOUR TI - Computer Aided Biomodeling and Analysis of Patient Specific Porous Titanium Mandibular Implants AU - Parthasarathy, Jayanthi AU - Starly, Binil AU - Raman, Shivakumar T2 - Journal of Medical Devices AB - Custom implants for the reconstruction of mandibular defects have recently gained importance due to their better performance over their generic counterparts. This is attributed to their precise adaptation to the region of implantation, reduced surgical times, and better cosmesis. Recent introduction of direct digital manufacturing technologies, which enable the fabrication of implants from patient specific data, has opened up a new horizon for the next generation of customized maxillofacial implants. In this article, we discuss a representative volume element based technique in which precisely defined porous implants with customized stiffness values are designed to match the stiffness and weight characteristics of surrounding healthy bone tissue. Dental abutment structures have been incorporated into the mandibular implant. Finite element analysis is used to assess the performance of the implant under masticatory loads. This design strategy lends itself very well to rapid manufacturing technologies based on metal sintering processes. DA - 2009/9/1/ PY - 2009/9/1/ DO - 10.1115/1.3192104 VL - 3 IS - 3 LA - en OP - SN - 1932-6181 1932-619X UR - http://dx.doi.org/10.1115/1.3192104 DB - Crossref KW - CT reconstruction mandibular implants KW - porous titanium layered manufacturing ER - TY - JOUR TI - A Lindenmayer system-based approach for the design of nutrient delivery networks in tissue constructs AU - Yasar, Ozlem AU - Lan, Shih-Feng AU - Starly, Binil T2 - Biofabrication AB - Large thick tissue constructs have reported limited success primarily due to the inability of cells to survive deep within the scaffold. Without access to adequate nutrients, cells placed deep within the tissue construct will die out, leading to non-uniform tissue regeneration. Currently, there is a necessity to design nutrient conduit networks within the tissue construct to enable cells to survive in the matrix. However, the design of complex networks within a tissue construct is challenging. In this paper, we present the Lindenmayer system, an elegant fractal-based language algorithm framework, to generate conduit networks in two- and three-dimensional architecture with several degrees of complexity. The conduit network maintains a parent–child relationship between each branch of the network. Several L-system parameters have been studied—branching angle, branch length, ratio of parent to child branch diameter, etc—to simulate several architectures under a given L-system notation. We have also presented a layered manufacturing-based UV-photopolymerization process using the Texas Instruments DLP™ system to fabricate the branched structures. This preliminary work showcases the applicability of L-system-based construct designs to drive scaffold fabrication systems. DA - 2009/12/1/ PY - 2009/12/1/ DO - 10.1088/1758-5082/1/4/045004 VL - 1 IS - 4 SP - 045004 J2 - Biofabrication OP - SN - 1758-5082 1758-5090 UR - http://dx.doi.org/10.1088/1758-5082/1/4/045004 DB - Crossref ER - TY - JOUR TI - The effects of customer rebates and retailer incentives on a manufacturer's profits and sales AU - Demirag, Ozgun Caliskan AU - Baysar, Ozgul AU - Keskinocak, Pinar AU - Swann, Julie L. T2 - Naval Research Logistics AB - Abstract In some industries such as automotive, production costs are largely fixed and therefore maximizing revenue is the main objective. Manufacturers use promotions directed to the end customers and/or retailers in their distribution channels to increase sales and market share. We study a game theoretical model to examine the impact of “retailer incentive” and “customer rebate” promotions on the manufacturer's pricing and the retailer's ordering/sales decisions. The main tradeoff is that customer rebates are given to every customer, while the use of retailer incentives is controlled by the retailer. We consider several models with different demand characteristics and information asymmetry between the manufacturer and a price discriminating retailer, and we determine which promotion would benefit the manufacturer under which market conditions. When demand is deterministic, we find that retailer incentives increase the manufacturer's profits (and sales) while customer rebates do not unless they lead to market expansion. When the uncertainty in demand (“market potential”) is high, a customer rebate can be more profitable than the retailer incentive for the manufacturer. With numerical examples, we provide additional insights on the profit gains by the right choice of promotion.© 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010 DA - 2009/// PY - 2009/// DO - 10.1002/nav.20390 SP - n/a-n/a KW - promotions KW - automotive industry KW - operations management-marketing ER - TY - JOUR TI - Bias in Markov models of disease. AU - Faissol, DM AU - Griffin, PM AU - Swann, JL T2 - Mathematical biosciences AB - We examine bias in Markov models of diseases, including both chronic and infectious diseases. We consider two common types of Markov disease models: ones where disease progression changes by severity of disease, and ones where progression of disease changes in time or by age. We find sufficient conditions for bias to exist in models with aggregated transition probabilities when compared to models with state/time dependent transition probabilities. We also find that when aggregating data to compute transition probabilities, bias increases with the degree of data aggregation. We illustrate by examining bias in Markov models of Hepatitis C, Alzheimer's disease, and lung cancer using medical data and find that the bias is significant depending on the method used to aggregate the data. A key implication is that by not incorporating state/time dependent transition probabilities, studies that use Markov models of diseases may be significantly overestimating or underestimating disease progression. This could potentially result in incorrect recommendations from cost-effectiveness studies and incorrect disease burden forecasts. DA - 2009/8// PY - 2009/8// DO - 10.1016/j.mbs.2009.05.005 VL - 220 IS - 2 SP - 143–156 UR - http://europepmc.org/abstract/med/19538974 KW - Markov model KW - Bias KW - Monte Carlo simulation 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 - CONF TI - Hub arc selection for freight consolidation AU - Carr, S. AU - Jang, W. S. C2 - 2009/// C3 - International conference on industrial engineering and engineering DA - 2009/// SP - 1961-1963 ER - TY - JOUR TI - Design of high-bandwidth high-precision flexure-based nanopositioning modules AU - Polit, Sebastian AU - Dong, Jingyan T2 - JOURNAL OF MANUFACTURING SYSTEMS AB - This paper presents the design of a single degree-of-freedom high-bandwidth high-precision nanopositioning module for high-throughput nanomanufacturing applications. Compared with widely used lumped-compliance mechanisms (using notch-flexure hinges) and distributed-compliance mechanisms (using compliant flexure beams), this nanopositioning module adopts a hybrid compliant-notch-flexure-based structure. This flexure design decouples the performance requirements for the structural bandwidth and parasitic accuracy that are correlated in the lumped-compliance mechanisms and distributed-compliance mechanisms. The parallelogram hybrid compliant-notch-flexure-based structure enables simultaneous achievement of a higher structural bandwidth and a smaller parasitic motion. The behavior of the nanopositioning module is analyzed theoretically with respect to its design parameters and performance objectives. Finite element analysis is adapted to study the dynamic responses and parasitic displacement of the designed nanopositioning module. The results from the theoretical and FEA analysis demonstrate the effectiveness of the hybrid compliant-notch-flexure design over commonly used lumped-compliance mechanisms and distributed-compliance mechanisms, especially when a high structural bandwidth is required for high-throughput nanomanufacturing applications. DA - 2009/7// PY - 2009/7// DO - 10.1016/j.jmsy.2010.01.001 VL - 28 IS - 2-3 SP - 71-77 SN - 1878-6642 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000278240700004&KeyUID=WOS:000278240700004 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 - JOUR TI - Determining the economics of new moulder configurations AU - Morales, L. AU - Lemaster, R. L. AU - Jackson, S. D. AU - Hodgson, T. J. T2 - Forest Products Journal AB - The moulder is one of the most widely used machines in the wood industry. Its function is to cut stock with rough dimensions to a finished width, thickness, and cross-sectional shape in one pass, making it cost effective to produce mouldings, floors, window and furniture components, etc. Today’s moulders are fast, safe, flexible, versatile, precise, and productive. Many different configurations can be selected when specifying the purchase of a moulder. The Moulder Economic Calculator (MEC) was developed to determine the economic impact of choosing different moulder configurations. The calculator uses input data on machine price and purchase method, machine configuration, production parameters, and production costs. The MEC program gives three types of outputs: surface quality, productivity, and costs. The MEC program is a flexible tool that allows the user to estimate the cost of machining one linear foot of wood. Some capabilities of the MEC program include determining the effect of machine price on mach... DA - 2009/// PY - 2009/// DO - 10.13073/0015-7473-59.11.60 VL - 59 IS - 11-12 SP - 60-66 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 - Total hip replacement in three cats: surgical technique, short-term outcome and comparison to femoral head ostectomy AU - Liska, W. D. AU - Doyle, N. AU - Marcellin-Little, D. J. AU - Osborne, J. A. T2 - VETERINARY AND COMPARATIVE ORTHOPAEDICS AND TRAUMATOLOGY AB - Summary Objective: To describe the surgical technique and clinical features of total hip replacement (THR) due to hip trauma in cats. Study design: Retrospective study. Sample population: Three client-owned cats that underwent THR to treat capital epiphyseal fractures, and five client-owned cats that underwent femoral head ostectomy (FHO). Methods: The clinical data included signalment, body weight, body condition score, diagnosis, implant size, surgical technique, intraoperative observations, and postoperative complications. Radiographic evaluation included implant positioning, cement mantle quality, and follow-up examination of the cement-bone interfaces. Orthopaedic examinations and client interviews were used to evaluate limb function. Results: The three cats that underwent THR had a mean body weight of 5.5 kg, a mean body condition score of 6/9, and a mean age of three years at the time of surgery. The average THR follow-up was 11 months. For the five cats that underwent FHO, the mean body weight was 6.3 kg, mean body score was 7/9, and mean age at the time of FHO was 2.5 years. The average FHO follow-up was 22 months. Hip flexion, hip extension, and thigh girth after THR compared favourably to similar measurements made after FHO. The functional outcomes after THR were excellent. The functional outcomes after FHO ranged from poor to excellent. Conclusion and clinical relevance: The recovery after THR was excellent based on clinical assessment of muscle mass, hip joint passive range of motion, gait, and owner assessment. Further blinded, randomised, and controlled trials of THR in cats are warranted. DA - 2009/// PY - 2009/// DO - 10.3415/VCOT-08-09-0087 VL - 22 IS - 6 SP - 505-510 SN - 0932-0814 KW - Cat KW - hip joint KW - total hip replacement KW - femoral head ostectomy 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 - Use of an Extracapsular Stabilization Technique to Repair Cruciate Ligament Ruptures in Two Avian Species AU - Chinnadurai, Sathya K. AU - Spodnick, Gary AU - Degernes, Laurel AU - DeVoe, Ryan S. AU - Marcellin-Little, Denis J. T2 - JOURNAL OF AVIAN MEDICINE AND SURGERY AB - An extracapsular stabilization technique was used to repair cruciate ligament ruptures in a trumpeter hornbill (Bycanistes bucinator) and an African grey parrot (Psittacus erithacus). The hornbill demonstrated cranial drawer motion and severe rotational instability of the stifle from ruptures of the cranial and caudal cruciate ligaments and stifle joint capsule. The luxation was reduced, and the fibula was cranially transposed, in relation to the tibiotarsus, and anchored with 2 positive profile threaded acrylic pins. A lateral extracapsular stabilization was then performed. The African grey parrot had a traumatic stifle luxation, and an open reduction and a lateral extracapsular stabilization were performed. Both birds regained function of the affected leg by 1 month after surgery. Extracapsular stabilization allows motion of the stifle joint to be maintained during the postoperative recovery period, an advantage over rigid stabilization. Maintaining motion in the stifle joint facilitates physical therapy and can aid in full recovery after avian stifle injuries. DA - 2009/12// PY - 2009/12// DO - 10.1647/1082-6742-23.4.307 VL - 23 IS - 4 SP - 307-313 SN - 1082-6742 KW - cruciate ligament KW - fibula KW - extracapsular stabilization KW - lateral suture technique KW - stifle joint luxation KW - orthopedics KW - avian KW - trumpeter hornbill KW - Bycanistes bucinator KW - African grey parrot KW - Psittacus erithacus 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 - Implementing a Master Surgical Scheduling Approach in a Regional Hospital AU - Denton, Brian T. AU - Oostrum, Jeroen M. AU - Houdenhoven, Mark AU - Wagelmans, Albert P. M. AU - Kazemier, Geert T2 - INTERFACES AB - The goal of “Practice Abstracts” is to present interesting, topical, and novel applications of operations research methodology to a wide range of industrial applications. “Practice Abstracts” are intended to provide Interfaces readers with short (2–4 page) descriptions of the most relevant aspects of operations research-based projects, in a form that is accessible to academics and practitioners in other organizations. Contributions should be sent for evaluation to the editor of “Practice Abstracts,” Brian T. Denton, Edward P. Fitts Department of Industrial and Systems Engineering, 376 Daniels Hall, North Carolina State University, 111 Lampe Drive, Campus Box 7906, Raleigh, North Carolina 27695 (bdenton@ncsu.edu). DA - 2009/// PY - 2009/// DO - 10.1287/inte.1090.0433 VL - 39 IS - 6 SP - 549-551 SN - 1526-551X KW - health care KW - planning KW - economics KW - hospitals KW - efficiency KW - simulation ER - TY - JOUR TI - Case Study of a Batch-Production and Inventory System AU - Denton, Brian T. AU - Winands, E. M. M. AU - Kok, A. G. AU - Timpe, C. T2 - INTERFACES AB - The goal of “Practice Abstracts” is to present interesting, topical, and novel applications of operations research methodology to a wide range of industrial applications. “Practice Abstracts” are intended to provide Interfaces readers with short (2–4 page) descriptions of the most relevant aspects of operations research-based projects, in a form that is accessible to academics and practitioners in other organizations. Contributions should be sent for evaluation to the editor of “Practice Abstracts,” Brian T. Denton, Edward P. Fitts Department of Industrial and Systems Engineering, 376 Daniels Hall, North Carolina State University, 111 Lampe Drive, Campus Box 7906, Raleigh, North Carolina 27695 (bdenton@ncsu.edu). DA - 2009/// PY - 2009/// DO - 10.1287/inte.1090.0431 VL - 39 IS - 6 SP - 552-554 SN - 1526-551X KW - production scheduling KW - inventory planning KW - sequencing ER - TY - CONF TI - Risk assessment for emergency management AU - Hsiang, S. M. C2 - 2009/// C3 - International Symposium on Emergency Management 2009 (ISEM'09) DA - 2009/// SP - 587-591 ER - TY - CONF TI - Human-machine co-construct intelligence on horizon year load in long term spatial load forecasting AU - Hong, T. AU - Hsiang, S. M. AU - Xu, L. AB - Horizon year load (HYL) is an important parameter in load forecasting algorithms that involve the Gompertz functions. Land use information has been utilized to determine HYL by computerized program. However, this approach fails when computer tries to seek optimal solution but ignores the physical meaning of the data, which can be overcome by the planners. This paper proposes and implements a methodology to determine horizon year load using land use information and planners' domain knowledge. The proposed methodology has been implemented and applied to several US utility companies to calculate the HYL of the small areas in the service territory. The resulting HYL has been used to drive the long-term electric load growth forecasting and to get satisfying forecast. C2 - 2009/// C3 - 2009 ieee power & energy society general meeting, vols 1-8 DA - 2009/// DO - 10.1109/pes.2009.5275308 SP - 1030-1035 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 - JOUR TI - Practice Abstracts AU - Denton, Brian T. AU - Van Saane, Lex AU - Reid, Ian T2 - INTERFACES AB - The goal of “Practice Abstracts” is to present interesting, topical, and novel applications of operations research methodology to a wide range of industrial applications. “Practice Abstracts” are intended to provide Interfaces readers with short (2–4 page) descriptions of the most relevant aspects of operations research-based projects, in a form that is accessible to academics and practitioners in other organizations. Contributions should be sent for evaluation to the editor of “Practice Abstracts,” Brian T. Denton, Edward P. Fitts Department of Industrial and Systems Engineering, 376 Daniels Hall, North Carolina State University, 111 Lampe Drive, Campus Box 7906, Raleigh, North Carolina 27695, bdenton@ncsu.edu. DA - 2009/// PY - 2009/// DO - 10.1287/inte.1090.0434 VL - 39 IS - 4 SP - 373-374 SN - 0092-2102 KW - industries: lumber and wood KW - Excel spreadsheet KW - mixed-integer programming (MIP) model ER - TY - JOUR TI - Performance evaluation and parametric analysis of our recommendations AU - Denton, B. T. T2 - Interfaces DA - 2009/// PY - 2009/// VL - 39 IS - 3 SP - 289-289 ER - TY - JOUR TI - Improving the utilization of catheterization labs at Scottsdale Healthcare AU - Denton, B. T. T2 - Interfaces DA - 2009/// PY - 2009/// VL - 39 IS - 3 SP - 288-288 ER - TY - JOUR TI - Human-Automation Interaction Strategies and Models for Life Science Applications AU - Kaber, David B. AU - Stoll, Norbert AU - Thurow, Kerstin AU - Green, Rebecca S. AU - Kim, Sang-Hwan AU - Mosaly, Prithima T2 - HUMAN FACTORS AND ERGONOMICS IN MANUFACTURING AB - Abstract The objective of this research was to identify current and future approaches to the design of automated systems for life science processes, including humans in control loops, in applications such as high‐throughput compound screening and high‐performance analytical chemistry. The identified approaches were classified according to existing theories of human‐centered automation, which provided a basis for projecting human performance implications. We provide background on the life sciences domain and established theories of types and levels of automation (LOAs) in complex human–machine systems. We describe specific forms of robotic and automated technologies used in life science applications and the general design of high‐throughput screening (HTS) and analytical systems to accommodate particular process configurations. Example classifications of life science automation (LSA) schemes are presented by referring to a taxonomy of LOAs from the literature. We project the implications of these classified forms of automation on human performance on the basis of prior empirical research in other domains. A mathematical model for predicting the cost of LSA from an operator perspective is also defined to support hypotheses for future study. Finally, we identify the need for additional empirical research on human performance consequences of LSA and remedial measures, including enhanced supervisory control interface design. © 2009 Wiley Periodicals, Inc. DA - 2009/// PY - 2009/// DO - 10.1002/hfm.20156 VL - 19 IS - 6 SP - 601-621 SN - 1090-8471 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 - Electrostatically Actuated Cantilever With SOI-MEMS Parallel Kinematic XY Stage AU - Dong, Jingyan AU - Ferreira, Placid M. T2 - JOURNAL OF MICROELECTROMECHANICAL SYSTEMS AB - This paper presents the design, analysis, fabrication, and characterization of an active cantilever device integrated with a high-bandwidth 2-DOF translational (XY) micropositioning stage. The cantilever is actuated electrostatically through a separate electrode that is fabricated underneath the cantilever. Torsion bars that connect the cantilever to the rest of the structure provide the required compliance for the cantilever's out-of-plane rotation. The active cantilever is carried by a micropositioning stage, which enables high-bandwidth scanning to allow manipulation in three dimensions. The design of the microelectromechanical system stage is based on a parallel kinematic mechanism (PKM). The PKM design decouples the motion in the X- and Y-directions while allowing for an increased motion range with linear kinematics in the operating region (or workspace). The trusslike structure of the PKM also results in increased stiffness and reduced mass of the stage. The integrated cantilever device is fabricated on a silicon-on-insulator (SOI) wafer using surface micromachining and deep reactive ion etching processes. The actuation electrode of the cantilever is fabricated on the handle layer, while the cantilever and the XY stage are at the device layer of the SOI wafer. Two sets of electrostatic linear comb drives are used to actuate the stage mechanism in the X- and Y-directions. The cantilever provides an out-of-plane motion of 7 mum at 4.5 V, while the XY stage provides a motion range of 24 mum in each direction at the driving voltage of 180 V. The resonant frequency of the XY stage under ambient conditions is 2090 Hz. A high quality factor (~210) is achieved from this parallel kinematic XY stage. The fabricated stages will be adapted as chip-scale manufacturing and metrology devices for nanomanufacturing and nanometrology applications. DA - 2009/6// PY - 2009/6// DO - 10.1109/JMEMS.2009.2020371 VL - 18 IS - 3 SP - 641-651 SN - 1057-7157 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000266723700015&KeyUID=WOS:000266723700015 KW - Active cantilever KW - comb drive KW - micropositioning stage KW - parallel kinematic mechanism (PKM) KW - tilt-plate actuator ER - TY - JOUR TI - Correlation of reactant particle size on residual stresses of nanostructured NiAl generated by self-propagating high-temperature synthesis AU - Rivero, Iris V. AU - Pantoya, Michelle L. AU - Rajamani, Karthik AU - Hsiang, Simon M. T2 - JOURNAL OF MATERIALS RESEARCH DA - 2009/6// PY - 2009/6// DO - 10.1557/JMR.2009.0240 VL - 24 IS - 6 SP - 2079-2088 SN - 2044-5326 ER - TY - JOUR TI - Comparison with historical data and impact AU - Denton, B. T. T2 - Interfaces DA - 2009/// PY - 2009/// VL - 39 IS - 3 SP - 289-290 ER - TY - JOUR TI - Analysis of current approach and methodology for improvements AU - Denton, B. T. T2 - Interfaces DA - 2009/// PY - 2009/// VL - 39 IS - 3 SP - 288-289 ER - TY - JOUR TI - Evaluation of a Shape Memory Alloy Reinforced Annuloplasty Band for Minimally Invasive Mitral Valve Repair AU - Purser, Molly F. AU - Richards, Andrew L. AU - Cook, Richard C. AU - Osborne, Jason A. AU - Cormier, Denis R. AU - Buckner, Gregory D. T2 - ANNALS OF THORACIC SURGERY AB - An in vitro study using explanted porcine hearts was conducted to evaluate a novel annuloplasty band, reinforced with a two-phase, shape memory alloy, designed specifically for minimally invasive mitral valve repair.In its rigid (austenitic) phase, this band provides the same mechanical properties as the commercial semi-rigid bands. In its compliant (martensitic) phase, this band is flexible enough to be introduced through an 8-mm trocar and is easily manipulated within the heart.In its rigid phase, the prototype band displayed similar mechanical properties to commercially available semi-rigid rings. Dynamic flow testing demonstrated no statistical differences in the reduction of mitral valve regurgitation. In its flexible phase, the band was easily deployed through an 8-mm trocar, robotically manipulated and sutured into place.Experimental results suggest that the shape memory alloy reinforced band could be a viable alternative to flexible and semi-rigid bands in minimally invasive mitral valve repair. DA - 2009/10// PY - 2009/10// DO - 10.1016/j.athoracsur.2009.04.133 VL - 88 IS - 4 SP - 1312-1316 SN - 1552-6259 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 - Laser micromachining for biomedical applications AU - Miller, Philip R. AU - Aggarwal, Ravi AU - Doraiswamy, Anand AU - Lin, Yi Jen AU - Lee, Yuan-Shin AU - Narayan, Roger J. T2 - JOM DA - 2009/9// PY - 2009/9// DO - 10.1007/s11837-009-0130-7 VL - 61 IS - 9 SP - 35-40 SN - 1047-4838 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 - 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 - Expression and Activity of COX-1 and 2 and 5-LOX in Joint Tissues from Dogs with Naturally Occurring Coxofemoral Joint Osteoarthritis AU - Lascelles, B. Duncan X. AU - King, Stephanie AU - Roe, Simon AU - Marcellin-Little, Denis J. AU - Jones, Samuel T2 - JOURNAL OF ORTHOPAEDIC RESEARCH AB - Abstract Understanding the neurobiology of pain in naturally occurring models of osteoarthritis (OA) may improve the understanding of human OA pain. Both COX and LOX have been associated with joint pain. This study evaluated COX‐1, COX‐2, and 5‐LOX expression and activity in a naturally occurring canine model of secondary OA. Hip joint capsule with synovial tissue (HJC) and femoral head subchondral bone (FH) was collected from normal dogs and dogs undergoing total hip replacement for coxofemoral joint OA. Tissues were analyzed for COX‐1, COX‐2, and LOX protein, and PGE 2 and LTB 4 . Significantly more COX‐2 protein was present in OA HJC than normal joints ( p = 0.0009). There was no significant difference in COX‐1 or LOX protein, although LOX protein was increased ( p = 0.069). PGE 2 concentration in normal and OA HJC was similar ( p = 1.0). LTB 4 concentration in OA HJC was significantly greater than normal HJC ( p = 0.028). Significantly more COX‐1 ( p = 0.0098), COX‐2 ( p = 0.0028), and LOX ( p = 0.0095) protein was present in OA FH tissue compared to normal FH tissue. There were no differences in PGE 2 or LTB 4 concentration in normal and OA FH tissue ( p = 0.77 and p = 0.11). Together, these data suggest both COX‐2 and 5‐LOX are appropriate targets for the management of pain associated with naturally occurring OA. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res DA - 2009/9// PY - 2009/9// DO - 10.1002/jor.20864 VL - 27 IS - 9 SP - 1204-1208 SN - 0736-0266 KW - canine KW - osteoarthritis KW - cyclooxygenase KW - lipoxygenase KW - eicosanoids ER - TY - JOUR TI - College students and computers: Assessment of usage patterns and musculoskeletal discomfort AU - Noack-Cooper, Karen L. AU - Sommerich, Carolyn M. AU - Mirka, Gary A. T2 - WORK-A JOURNAL OF PREVENTION ASSESSMENT & REHABILITATION AB - A limited number of studies have focused on computer-use-related MSDs in college students, though risk factor exposure may be similar to that of workers who use computers. This study examined computer use patterns of college students, and made comparisons to a group of previously studied computer-using professionals. 234 students completed a web-based questionnaire concerning computer use habits and physical discomfort respondents specifically associated with computer use. As a group, students reported their computer use to be at least 'Somewhat likely' 18 out of 24 h/day, compared to 12 h for the professionals. Students reported more uninterrupted work behaviours than the professionals. Younger graduate students reported 33.7 average weekly computing hours, similar to hours reported by younger professionals. Students generally reported more frequent upper extremity discomfort than the professionals. Frequent assumption of awkward postures was associated with frequent discomfort. The findings signal a need for intervention, including, training and education, prior to entry into the workforce. Students are future workers, and so it is important to determine whether their increasing exposure to computers, prior to entering the workforce, may make it so they enter already injured or do not enter their chosen profession due to upper extremity MSDs. DA - 2009/// PY - 2009/// DO - 10.3233/WOR-2009-0827 VL - 32 IS - 3 SP - 285-298 SN - 1875-9270 KW - Computer KW - VDT KW - college students KW - musculoskeletal discomfort ER - TY - JOUR TI - Analysis of Alternative Keyboards Using Learning Curves AU - Anderson, Allison M. AU - Mirka, Gary A. AU - Joines, Sharon M. B. AU - Kaber, David B. T2 - HUMAN FACTORS AB - To quantify learning percentages for alternative keyboards (chord, contoured split, Dvorak, and split fixed angle) and understand how physical, cognitive, and perceptual demand affect learning.Alternative keyboards have been shown to offer ergonomic benefits over the conventional, single-plane QWERTY keyboard design, but productivity-related challenges may hinder their widespread acceptance.Sixteen participants repeatedly typed a standard text passage using each alternative keyboard. Completion times were collected and subsequent learning percentages were calculated. Participants were asked to subjectively rate the physical, cognitive, and perceptual demands of each keyboard, and these values were then related to the calculated learning percentages.Learning percentage calculations revealed the percentage for the split fixed-angle keyboard (90.4%) to be significantly different (p < .05) from the learning percentages for the other three keyboards (chord, 77.3%; contour split, 76.9%; Dvorak, 79.1%). The average task completion time for the conventional QWERTY keyboard was 40 s, and the average times for the fifth trial on the chord, contoured split, Dvorak, and split fixed-angle keyboards were 346, 69, 181, and 42 s, respectively.Productivity decrements can be quickly regained for the split fixed-angle and contour split keyboard but will take considerably longer for Dvorak and chord keyboards. The split fixed-angle keyboard involved physical learning, whereas the others involved some combination of physical and cognitive learning, a result supported by the subjective responses.Understanding the changes in task performance time that come with learning can provide additional information for a cost-benefit analysis when considering the implementation of ergonomic interventions. DA - 2009/2// PY - 2009/2// DO - 10.1177/0018720808329844 VL - 51 IS - 1 SP - 35-45 SN - 1547-8181 ER - TY - JOUR TI - A survey on fuzzy relational equations, part I: Classification and solvability AU - Li, P. K. AU - Fang, S. C. T2 - Fuzzy Optimization and Decision Making DA - 2009/// PY - 2009/// VL - 8 IS - 2 SP - 179-229 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 - Optimizing the Start Time of Statin Therapy for Patients with Diabetes AU - Denton, Brian T. AU - Kurt, Murat AU - Shah, Nilay D. AU - Bryant, Sandra C. AU - Smith, Steven A. T2 - MEDICAL DECISION MAKING AB - Background . Clinicians often use validated risk models to guide treatment decisions for cardiovascular risk reduction. The most common risk models for predicting cardiovascular risk are the UKPDS, Framingham, and Archimedes models. In this article, the authors propose a model to optimize the selection of patients for statin therapy of hypercholesterolemia, for patients with type 2 diabetes, using each of the risk models. For each model, they evaluate the role of age, gender, and metabolic state on the optimal start time for statins. Method . Using clinical data from the Mayo Clinic electronic medical record, the authors construct a Markov decision process model with health states composed of cardiovascular events and metabolic factors such as total cholesterol and high-density lipoproteins. They use it to evaluate the optimal start time of statin treatment for different combinations of cardiovascular risk models and patient attributes. Results . The authors find that treatment decisions depend on the cardiovascular risk model used and the age, gender, and metabolic state of the patient. Using the UKPDS risk model to estimate the probability of coronary heart disease and stroke events, they find that all white male patients should eventually start statin therapy; however, using Framingham and Archimedes models in place of UKPDS, they find that for male patients at lower risk, it is never optimal to initiate statins. For white female patients, the authors also find some patients for whom it is never optimal to initiate statins. Assuming that age 40 is the earliest possible start time, the authors find that the earliest optimal start times for UKPDS, Framingham, and Archimedes are 50, 46, and 40, respectively, for women. For men, the earliest optimal start times are 40, 40, and 40, respectively. Conclusions . In addition to age, gender, and metabolic state, the choice of cardiovascular risk model influences the apparent optimal time for starting statins in patients with diabetes. DA - 2009/5// PY - 2009/5// DO - 10.1177/0272989x08329462 VL - 29 IS - 3 SP - 351-367 SN - 0272-989X KW - diabetes KW - statins KW - Markov decision process ER - TY - JOUR TI - Ergonomic Risk Factors for Low Back Pain in North Carolina Crab Pot and Gill Net Commercial Fishermen AU - Kucera, Kristen L. AU - Loomis, Dana AU - Lipscomb, Hester J. AU - Marshall, Stephen W. AU - Mirka, Gary A. AU - Daniels, Julie L. T2 - AMERICAN JOURNAL OF INDUSTRIAL MEDICINE AB - Abstract Background The objective of this research was to determine the association between LBP that limited or interrupted fishing work and ergonomic low back stress measured by (1) self‐reported task and (2) two ergonomic assessment methods of low back stress. Methods Eligible participants were from a cohort of North Carolina commercial fishermen followed for LBP in regular clinic visits from 1999 to 2001 (n = 177). Work history, including crab pot and gill net fishing task frequency, was evaluated in a telephone questionnaire (n = 105). Ergonomic exposures were measured in previous study of 25 fishermen using two methods. The occurrence rate of LBP that limited or interrupted fishing work since last visit (severe LBP) was evaluated in a generalized Poisson regression model. Results Predictors of severe LBP included fishing with crew members and a previous history of severe LBP. Among crab pot and gill net fishermen (n = 89), running pullers or net reels, sorting catch, and unloading catch were associated with an increased rate of LBP. Percent of time in forces >20 lb while in non‐neutral trunk posture, spine compression >3,400 N, and National Institute of Occupational Safety and Health lifting indices >3.0 were associated with LBP. Conclusions Tasks characterized by higher (unloading boat and sorting catch) and lower (running puller or net reel) ergonomic low back stress were associated with the occurrence of severe LBP. History of LBP, addition of crew members, and self‐selection out of tasks were likely important contributors to the patterns of low back stress and outcomes we observed. Based on the results of this study, a participatory ergonomic intervention study is currently being conducted to develop tools and equipment to decrease low back stress in commercial crab pot fishing. Am. J. Ind. Med. 52:311–321, 2009. © 2009 Wiley‐Liss, Inc. DA - 2009/4// PY - 2009/4// DO - 10.1002/ajim.20676 VL - 52 IS - 4 SP - 311-321 SN - 1097-0274 KW - epidemiology KW - musculoskeletal disorders KW - work exposure KW - PATH KW - CABS ER - TY - JOUR TI - Design and evaluation of dynamic text-editing methods using foot pedals AU - Kim, Sang-Hwan AU - Kaber, David B. T2 - INTERNATIONAL JOURNAL OF INDUSTRIAL ERGONOMICS AB - The objective of this study was to design and evaluate new dynamic text-editing methods (chatting, instant messenger) using a foot pedal control. A first experiment was to assess whether the foot-based method enhanced editing performance compared to conventional mouse use and to identify which type of foot control is most convenient for users. Five prototype methods including four new methods (two pedals or one pedal, 0 order or 1st order control), and one mouse method were developed and tested by performing a task requiring changing text sizes, dynamically. Results revealed methods involving 1st order pedal control to be comparable to the conventional method in task completion time, accuracy and subjective workload. Among the four foot control prototypes, two pedals with 1st order control was superior to in performance. A second experiment was conducted to test another prototype foot-based method for controlling font face, size, and color through feature selection with the left pedal and level selection with the right pedal. Text-editing performance was compared to conventional mouse-based editing. Results showed the foot pedals to degrade performance in terms of task completion time. However, the prototype interface has the advantage of making certain system functionality accessible to special populations that might not otherwise be able to use dynamic text-editing applications. Subjective comments demonstrated the foot pedal methods to be considered useful, time efficient and to reduce workload. It was observed that skilled users might perceive some relief from cumbersome mouse handling behaviors during typing. Although the foot pedal control was not revealed to significantly increase text-editing performance over conventional mousing, the use of foot pedals may be considered in computing operations, including dynamic text-editing tasks, as an alternative or additional input method, particularly for special populations. The development and evaluation of foot control interaction methods for text editing may provide useful insight for human-computer system designers considering the use of additional input devices or ways to support user expressions of emotion in text. The foot control approach may also be useful in interaction design for special populations (with functional limitations of the upper limbs) in terms of accessibility. DA - 2009/3// PY - 2009/3// DO - 10.1016/j.ergon.2008.07.010 VL - 39 IS - 2 SP - 358-365 SN - 1872-8219 KW - Foot pedals KW - Text editing KW - Control systems ER - TY - JOUR TI - Isotopic Fractionation of Methyl tert-Butyl Ether Suggests Different Initial Reaction Mechanisms during Aerobic Biodegradation AU - McKelvie, Jennifer R. AU - Hyman, Michael R. AU - Elsner, Martin AU - Smith, Christy AU - Aslett, Denise M. AU - Lacrampe-Couloume, Georges AU - Lollar, Barbara Sherwood T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Carbon isotopic enrichment factors (εC) measured during cometabolic biodegradation of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) by Pseudonocardia tetrahydrofuranoxydans strain K1 were −2.3 ± 0.2‰, −1.7 ± 0.2‰, and −1.7 ± 0.3‰, respectively. The measured carbon apparent kinetic isotope effect was 1.01 for all compounds, consistent with the expected kinetic isotope effects for both oxidation of the methoxy (or ethoxy) group and enzymatic SN1 biodegradation mechanisms. Significantly, δ13C measurements of the tert-butyl alcohol and tert-amyl alcohol products indicated that the tert-butyl and tert-amyl groups do not participate in the reaction and confirmed that ether biodegradation by strain K1 involves oxidation of the methoxy (or ethoxy) group. Measured hydrogen isotopic enrichment factors (εH) were −100 ± 10‰, −73 ± 7‰, and −72 ± 2‰ for MTBE, ETBE, and TAME respectively. Previous results reported for aerobic biodegradation of MTBE by Methylibium petroleiphilum PM1 and Methylibium R8 showed smaller εH values (−35‰ and −42‰, respectively). Plots of Δ2H/ Δ13C show different slopes for strain K1 compared with strains PM1 and R8, suggesting that different mechanisms are utilized by K1 and PM1/R8 during aerobic MTBE biodegradation. DA - 2009/4/15/ PY - 2009/4/15/ DO - 10.1021/es803307y VL - 43 IS - 8 SP - 2793-2799 SN - 1520-5851 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 - Multi-objective optimisation of gas carburising process in batch furnaces with endothermic carburising atmosphere AU - Karabelchtchikova, O. AU - Hsiang, S. M. AU - Sisson, R. D., Jr. T2 - SURFACE ENGINEERING AB - A methodology for multi-objective optimisation of gas carburising heat treatment has been developed in terms of cost, cycle time and quality of carburised parts. The optimisation strategy is based on: modelling the effect of process parameters (carbon potential, temperature and time) on the mass transfer coefficient and carbon diffusivity in austenite, correlating the observed variations in the process parameters on the carburising kinetics, and developing a robust multiobjective optimisation technique to achieve the desired case depth with minimum cost and minimum case depth variation. The tradeoff between these two objective functions corresponded to carburising at 938·5°C and carbon potential of 1·14 wt-%C. This combination produced the target case depth of 0·6 mm with corresponding ±0·05 mm case depth variation and minimum total cycle cost. Overall, application of this multi-objective optimisation will result in significant energy reduction by shortening cycle time and thereby enhancing furnace capacity. DA - 2009/1// PY - 2009/1// DO - 10.1179/174329408X315634 VL - 25 IS - 1 SP - 43-49 SN - 1743-2944 KW - Optimisation KW - Gas carburising KW - Model KW - Cost KW - Energy consumption KW - Efficiency 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 - Biomechanical evaluation of postures assumed when harvesting from bush crops AU - Jin, Sangeun AU - McCulloch, Ryan AU - Mirka, Gary A. T2 - INTERNATIONAL JOURNAL OF INDUSTRIAL ERGONOMICS AB - The objectives of this research were to explore the changes in the low back biomechanical responses during a harvesting task as a function of different harvesting techniques/postures and to explore the effects of an ergonomic intervention designed to reduce the low back stress during this work activity. Nine participants performed a series of simulated harvesting activities in a laboratory setting using four different harvesting techniques: full kneeling posture, squatting posture, stooping posture and kneeling on a knee support device (the intervention). As they performed these tasks the activity of muscles of the torso and thighs was captured using electromyography and trunk kinematics were captured using the lumbar motion monitor and a magnetic field-based motion tracking system. The results showed that (1) three postures – knee support, squatting, and stooping – required high flexion of low back (more than 60°) and (2) squatting and stooping postures showed significantly higher passive tissue moment compared with two kneeling postures. The results also indicate that the beneficial aspects of the knee support intervention appear to be outweighed by reduced productivity and the high degree of trunk flexion and that the current strategy used by these workers of alternating between the various harvesting postures may be the best strategy available. Understanding how changes in harvesting technique affect lumbar biomechanics can help ergonomists design effective interventions for the prevention of back injury in farm workers. DA - 2009/3// PY - 2009/3// DO - 10.1016/j.ergon.2008.07.005 VL - 39 IS - 2 SP - 347-352 SN - 1872-8219 KW - Harvesting postures KW - Ergonomic intervention KW - EMG 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 - 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 - 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 - Introduction: 2008 Franz Edelman Award for Achievement in Operations Research and the Management Sciences AU - Denton, Brian T. AU - Sodhi, ManMohan S. T2 - INTERFACES AB - This special issue of Interfaces is devoted to the finalists of the 37th annual competition for the Franz Edelman Award for Achievement in Operations Research and the Management Sciences, the profession's prestigious award for the practice of operations research. Of the six entries, one demonstrates the benefits derived from OR/MS-based scheduling for the care of the elderly in Sweden. The second shows dramatic improvement in air traffic management with new weather-system-related policies in the United States. The third shows how to improve network configuration and routing of natural gas in Norway and neighboring countries. The fourth shows how to place contaminant sensors in water sources and its application in the United States. The fifth reflects productivity improvements in print shops and document manufacturing facilities, also in the United States. The final entry shows how OR/MS was used to construct a brand new timetable for the passenger railway system in The Netherlands to account for much higher demand on the system. DA - 2009/// PY - 2009/// DO - 10.1287/inte.1080.0422 VL - 39 IS - 1 SP - 2-5 SN - 0092-2102 KW - professional: comments on 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 - 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 - The effects of a suspended-load backpack on gait AU - Xu, Xu AU - Hsiang, Simon M. AU - Mirka, Gary A. T2 - GAIT & POSTURE AB - A suspended-load backpack is a device that is designed to capture the mechanical energy created as a suspended backpack load oscillates vertically on the back during gait. The objective of the current study was to evaluate the effect of a suspended-load backpack system on selected temporal and kinetics parameters describing gait. Nine male participants carried a suspended-load backpack as they walked on an instrumented treadmill with varied levels of load (no backpack, 22.5 kg, and 29.3 kg) and walking speed (1.16 m/s, 1.43 m/s, 1.70 m/s). As the participants performed this treadmill task, ground reaction forces were collected from an instrumented treadmill system. From these data, temporal variables (cycle time, single support time, and double support time) and kinetic variables (normalized weight acceptance force, normalized push-off force, and normalized mid-stance force) were derived. The results showed that the response of the temporal variables were consistent with previous studies of conventional (i.e. stable load) backpacks. The response of the normalized push-off force, however, showed that increasing walking speed significantly (p<0.05) decreased the magnitude of this force, a result contrary to the literature concerning conventional backpacks where this force has been shown to significantly increase. Further evaluation revealed that this reduction in force was the result of a phase shift between the movement of the carried load and the movement of the torso. This suggests that the motion of the load in a suspended-load backpack influences the gait biomechanics and should be considered as this technology advances. DA - 2009/1// PY - 2009/1// DO - 10.1016/j.gaitpost.2008.06.008 VL - 29 IS - 1 SP - 151-153 SN - 1879-2219 KW - Suspended-load backpack KW - Ground reaction force ER - TY - JOUR TI - An Optimal-Control Model of Vision-Gait Interaction in a Virtual Walkway AU - Dong, Haining AU - Hsiang, Simon M. AU - Smith, James L. T2 - IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS AB - The specific aim of this paper is to model the vision-posture coupling behavior, which is important for astronauts to stabilize their locomotion in partial gravities as the national aeronautics and space administration plans for manned missions to the moon and mars . As such, an optimal scheme is assumed in postural-control processes to stabilize visual optical flows. An experiment was conducted, in which human subjects attended a visual-gait tracking task. In tracking control, head position errors can be used to regulate inputs so that appropriate compensatory changes can be obtained. The ldquooptimalrdquo scheme describes a compromise between postural adjusting efforts and tracking errors. The results show that the proposed optimal-control model describes the gait tracking process more reliably than McRuer's crossover model of the human-plant compensatory behaviors. In practice, if the tracking goal is to be roughly right rather than precisely wrong, this paper also provides the experimental data regarding the human tolerance and achievable performance under various unloading conditions and tracking difficulties. This information and related experimental setup could also be applied to postsurgery gait rehabilitation. DA - 2009/2// PY - 2009/2// DO - 10.1109/TSMCB.2008.2003427 VL - 39 IS - 1 SP - 156-166 SN - 1083-4419 KW - Gait KW - optimal control KW - postural control KW - simulated partial gravity KW - visual tracking ER - TY - JOUR TI - An evaluation of arborist handsaws AU - Mirka, Gary A. AU - Jin, Sangeun AU - Hoyle, Jeff T2 - APPLIED ERGONOMICS AB - A review of the scientific literature reveals little research on the ergonomics of handsaws and no literature on the specific challenges of arborist saws (saws for cutting and pruning living trees). This study was designed to provide some insight into the effects of saw design and height of sawing activity on the biomechanical response of the upper extremity. Eighteen participants performed a simple sawing task at three different heights using six different arborist handsaws. As they performed this task, the electromyographic activity of several muscle groups of the forearm (flexor and extensor digitorum), arm (biceps brachii long and short heads) and shoulder girdle (posterior deltoid, infraspinatus and latissimus dorsi) were sampled. Also gathered were the wrist postures in the radial/ulnar plane at the beginning and ending of the sawing stroke, the time to complete the sawing task and a subjective ranking of the six different saws. The results show an interesting mix of biomechanical and subjective responses that provide insight into handsaw design. First, there were tradeoffs among muscle groups as a function of work height. As work height increased the biceps muscles increased their activation levels (∼19%) while the posterior deltoid activity decreased (∼17%) with the higher location. The results also showed the benefits of a bent handle design (average 21% reduction in ulnar deviation). The subjective responses of the participants generally supported the productivity data, with the saws demonstrating the shortest task completion time also being the ones most highly ranked. Understanding the stresses placed on the upper extremity during sawing activities, and design features that can reduce these stresses, may help saw designers to create products that reduce the risk of injury in workers who use handsaws. DA - 2009/1// PY - 2009/1// DO - 10.1016/j.apergo.2008.02.011 VL - 40 IS - 1 SP - 8-14 SN - 0003-6870 KW - Handsaws KW - Shoulder KW - Wrist KW - Biomechanics ER - TY - BOOK TI - Engineering economic analysis AU - Newman, D. G. AU - Eschenbach, T. G. AU - Lavelle, J. P. DA - 2009/// PY - 2009/// PB - Oxford, NY: Oxford University Press SN - 9780195335415 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 -