TY - JOUR TI - Electro-Discharge of Nanocrystalline Nb-Al Powders Produced by Mechanical Alloying AU - Rock, C AU - Qiu, Jun AU - Okazaki, K T2 - Journal of Materials Science DA - 1998/// PY - 1998/// DO - 10.1023/A:1004386822343 VL - 33 IS - 1 SP - 241–246 SN - 0022-2461 UR - http://dx.doi.org/10.1023/A:1004386822343 ER - TY - CONF TI - Predictable Scheduling of a Single Machine with Breakdowns and Sensitive Jobs AU - O’Donovan, R. AU - McKay, K.N. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 1998/4// CY - Montreal, Canada DA - 1998/4// PY - 1998/4// ER - TY - CONF TI - Empirical Evaluation of Heuristics: A Tutorial AU - Rardin, R.L. AU - Uzsoy, R. T2 - INFORMS National Meeting C2 - 1998/4// CY - Montreal, Canada DA - 1998/4// PY - 1998/4// ER - TY - CONF TI - Decomposition Procedures for Scheduling Complex Job Shops AU - Demirkol, E. AU - Uzsoy, R. AU - Wang, C.S. T2 - Sixth International Workshop on Project Management and Scheduling C2 - 1998/7// C3 - Proceedings of the Sixth International Workshop on Project Management and Scheduling DA - 1998/7// PY - 1998/7// ER - TY - JOUR TI - Supply Chain Management for Companies with Product Recovery and Remanufacturing Capability AU - Uzsoy, R. AU - Venkatachalam, G. T2 - International Journal of Environmentally Conscious Design and Manufacturing DA - 1998/// PY - 1998/// VL - 7 SP - 59–72 ER - TY - SOUND TI - Predictable Scheduling of Job Shops Subject To Machine Breakdowns AU - Uzsoy, R. AU - Mehta, S.V. DA - 1998/3// PY - 1998/3// ER - TY - SOUND TI - A Senior Design Course with Industrial Experience AU - Uzsoy, R. DA - 1998/4// PY - 1998/4// ER - TY - SOUND TI - Management of Spare Parts Inventories in a Wafer Fabrication Facility AU - Teyner, T. AU - Uzsoy, R. DA - 1998/5// PY - 1998/5// ER - TY - SOUND TI - Maintenance Management Problems in a Semiconductor Wafer Fabrication Facility AU - Uzsoy, R. DA - 1998/11// PY - 1998/11// ER - TY - CONF TI - Effects of epitaxial silicon technology on the manufacturing performance of wafer fabrication lines AU - Hughes, J.C. AU - Neudeck, G.W. AU - Uzsoy, R. T2 - Twenty Third IEEE/CPMT International Electronics Manufacturing Technology Symposium. 1998 IEMT Symposium AB - This paper evaluates the manufacturing benefits of silicon selective epitaxial growth (SEG) as a front-end device isolation fabrication process. The technology is evaluated in two different ways. First, the cost of ownership (COO) of the equipment is used to obtain a cost of process (COP) for SEG and compared to the current alternatives, which are local oxidation of silicon (LOCOS) and shallow trench isolation (STI). Results of the processes, up to the point where the CMOS MOSFETs are produced, show that cost reductions using SEG was more than 22% compared to LOCOS and 49% compared to STI. The second evaluation approach examines the effects of the three processes on the mean and variance of fabrication cycle time using queuing network models. These results indicate that the mean cycle time for the portion of the line being considered could drop by as much as one third when the dielectric isolation by SEG (DI-SEG) process is implemented. Significant increases in line yield may also result. C2 - 1998/// C3 - Twenty Third IEEE/CPMT International Electronics Manufacturing Technology Symposium (Cat. No.98CH36205) DA - 1998/// PY - 1998/10/19/ DO - 10.1109/iemt.1998.731090 PB - IEEE UR - http://dx.doi.org/10.1109/iemt.1998.731090 ER - TY - JOUR TI - Control of a batch-processing machine: A computational approach AU - Avramidis, A. N. AU - Healy, K.J. AU - Uzsoy, R. T2 - International Journal of Production Research AB - Batch processing machines, where a number of jobs are processed simultaneously as a batch, occur frequently in semiconductor manufacturing environments, particularly at diffusion in wafer fabrication and at burn-in in final test. In this paper we consider a batch-processing machine subject to uncertain (Poisson) job arrivals. Two different cases are studied: (1) the processing times of batches are independent and identically distributed (IID), corresponding to a diffusion tube; and (2) the processing time of each batch is the maximum of the processing times of its constituent jobs, where the processing times of jobs are IID, modelling a burn-in oven. We develop computational procedures to minimize the expected long-run-average number of jobs in the system under a particular family of control policies. The control policies considered are threshold policies, where processing of a batch is initiated once a certain number of jobs have accumulated in the system. We present numerical examples of our methods and verify their accuracy using simulation. DA - 1998/11// PY - 1998/11// DO - 10.1080/002075498192355 VL - 36 IS - 11 SP - 3167-3181 J2 - International Journal of Production Research LA - en OP - SN - 0020-7543 1366-588X UR - http://dx.doi.org/10.1080/002075498192355 DB - Crossref ER - TY - JOUR TI - Benchmarks for shop scheduling problems AU - Demirkol, Ebru AU - Mehta, Sanjay AU - Uzsoy, Reha T2 - European Journal of Operational Research AB - In this paper we present extensive sets of randomly generated test problems for the problems of minimizing makespan (Cmax) and maximum lateness (Lmax) in flow shops and job shops. The 600 problems include three different types of routings, four different due date configurations and a variety of problem sizes. The problems, as well as the best existing solution and a lower bound on the optimal value are available on the world-wide web. DA - 1998/8// PY - 1998/8// DO - 10.1016/s0377-2217(97)00019-2 VL - 109 IS - 1 SP - 137-141 J2 - European Journal of Operational Research LA - en OP - SN - 0377-2217 UR - http://dx.doi.org/10.1016/s0377-2217(97)00019-2 DB - Crossref KW - combinatorial optimization KW - scheduling KW - benchmarks ER - TY - JOUR TI - Predictable scheduling of a job shop subject to breakdowns AU - Mehta, S.V. AU - Uzsoy, R.M. T2 - IEEE Transactions on Robotics and Automation AB - Schedule modification may delay or render infeasible the execution of external activities planned on the basis of the predictive schedule. Thus it is of interest to develop predictive schedules which can absorb disruptions without affecting planned external activities, while maintaining high shop performance. We present a predictable scheduling approach where the predictive schedule is built with such objectives. The procedure inserts additional idle time into the schedule to absorb the impacts of breakdowns. The amount and location of the additional idle time is determined from the breakdown and repair distributions as well as the structure of the predictive schedule. The effects of disruptions on planned support activities are measured by the deviations of job completion times in the realized schedule from those in the predictive schedule. We apply our approach to minimizing maximum lateness in a job shop environment with random machine breakdowns, and show that it provides high predictability with minor sacrifices in shop performance. DA - 1998/6// PY - 1998/6// DO - 10.1109/70.678447 VL - 14 IS - 3 SP - 365-378 J2 - IEEE Trans. Robot. Automat. OP - SN - 1042-296X UR - http://dx.doi.org/10.1109/70.678447 DB - Crossref KW - job shop KW - predictable scheduling KW - rescheduling KW - scheduling KW - uncertainties ER - TY - JOUR TI - Maintenance scheduling and staffing policies in a wafer fabrication facility AU - Mosley, S.A. AU - Teyner, T. AU - Uzsoy, R.M. T2 - IEEE Transactions on Semiconductor Manufacturing AB - We examine how to reduce the adverse effects of machine down time by prioritizing production equipment for attention by a limited number of maintenance personnel. The maintenance scheduling policies use system information to determine which machines are the most critical at a given time. This information includes repair times, queue lengths, due dates, available capacity, and steady-state utilizations. The effects of different staffing levels are also considered. A discrete-event simulation model of a wafer fabrication facility is used to examine the performance of the different policies. Results indicate that the choice of maintenance scheduling policy can significantly affect system performance under restrictive staffing-levels. Moreover, factory performance is shown to be sensitive to small changes in staffing level. DA - 1998/5// PY - 1998/5// DO - 10.1109/66.670182 VL - 11 IS - 2 SP - 316-323 J2 - IEEE Trans. Semicond. Manufact. OP - SN - 0894-6507 UR - http://dx.doi.org/10.1109/66.670182 DB - Crossref KW - maintenance management KW - scheduling KW - staffing KW - wafer fabrication ER - TY - JOUR TI - Minimizing total tardiness on a batch processing machine with incompatible job families AU - Mehta, Sanjay V. AU - Uzsoy, Reha T2 - IIE Transactions AB - Abstract Motivated by an application in semiconductor manufacturing, we study the problem of minimizing total tardiness on a batch processing machine with incompatibl8e job families, where all jobs of the same family have identical processing times and jobs of different families cannot be processed together. We present a dynamic programming algorithm which has polynomial time complexity when the number of job families and the batch machine capacity are fixed. We also examine various heuristic solution procedures which can provide near optimal solutions in a reasonable amount of computation time. DA - 1998/2// PY - 1998/2// DO - 10.1080/07408179808966448 VL - 30 IS - 2 SP - 165-178 J2 - IIE Transactions LA - en OP - SN - 0740-817X 1545-8830 UR - http://dx.doi.org/10.1080/07408179808966448 DB - Crossref ER - TY - JOUR TI - Scheduling a single batch processing machine with secondary resource constraints AU - Kempf, Karl G. AU - Uzsoy, Reha AU - Wang, Cheng-Shuo T2 - Journal of Manufacturing Systems AB - This paper studies the problems of minimizing total completion time (ΣCi) and makespan (Cmax) on a single batch processing machine with job families and secondary resource constraints. The motivation for this problem is the burn-in operation in the final testing stage of semiconductor manufacturing, where both oven capacity and the number of boards available may constrain scheduling decisions. Because both problems are NP-hard, integer programming formulations are developed for special cases and are then used to develop heuristics. Extensive computational experiments show that the heuristics are capable of consistently obtaining good solutions in modest CPU times. DA - 1998/1// PY - 1998/1// DO - 10.1016/s0278-6125(98)80008-3 VL - 17 IS - 1 SP - 37-51 J2 - Journal of Manufacturing Systems LA - en OP - SN - 0278-6125 UR - http://dx.doi.org/10.1016/s0278-6125(98)80008-3 DB - Crossref KW - scheduling KW - semiconductor manufacturing KW - batch processing machines KW - heuristics ER - TY - JOUR TI - A capacity allocation problem with integer side constraints AU - Toktay, L.Beril AU - Uzsoy, Reha T2 - European Journal of Operational Research AB - We address a capacity allocation problem arising as a subproblem of an artificial intelligence-based scheduling system for a semiconductor wafer fabrication facility. Tooling constraints, setup considerations and differences in machine capabilities are taken into account. Focusing on the objectives of maximizing throughput and minimizing deviation from predetermined production goals, we formulate the problem as a maximum flow problem on a bipartite network with integer side constraints and develop efficient heuristics which obtain near-optimal solutions in negligible computation time. The type of network flow problem we study has not been addressed in the literature to date and is of considerable theoretical interest. From a practical point of view, the network flow model of the problem and the algorithms developed for its solution are applicable to a wide range of production settings. DA - 1998/8// PY - 1998/8// DO - 10.1016/s0377-2217(98)80011-8 VL - 109 IS - 1 SP - 170-182 J2 - European Journal of Operational Research LA - en OP - SN - 0377-2217 UR - http://dx.doi.org/10.1016/s0377-2217(98)80011-8 DB - Crossref KW - scheduling KW - network flows KW - semiconductor manufacturing ER - TY - CONF TI - A Four-Dimensional Road-Mapping Framework for Power Packaging Technology AU - Hopkins, D. C. AU - O’Mathuna, S. C. AU - Alderman, A.N. T2 - 1998 International Microelectronics Assembly and Packaging Society (IMAPS) International Symposium on Microelectronics C2 - 1998/// C3 - Proceedings of the 1998 IMAPS International Symposium on Microelectronics CY - San Diego, CA DA - 1998/// PY - 1998/11/1/ ER - TY - JOUR TI - Thermal Impedance and Induced Stress in a Power Package Due to Variation in Layer Thickness AU - Hopkins, D.C. AU - Pitarressi, J.M. T2 - International Journal of Microcircuits and Electronic Packaging DA - 1998/// PY - 1998/// ER - TY - JOUR TI - Systems Design Considerations for Using a Direct-Attached-Ceramic MMC Power Package AU - Hopkins, D.C. AU - Pitarressi, J.M. AU - Karker, J.A. T2 - international journal on microelectronics reliability DA - 1998/// PY - 1998/// ER - TY - CONF TI - Fusing a hyper-ellipsoid clustering Kohonen network with the Julier-Uhlmann-Kalman filter for autonomous mobile robot map building and tracking AU - Janet, J.A. AU - White, M.W. AU - Kay, M.G. AU - Sutton, J.C. AU - Brickley, J.J. AB - We fuse a self-organizing hyperellipsoid clustering (HEC) Kohonen neural network with the Julier-Uhlmann-Kalman filter (JUKF) to perform map building and low-level position estimation. The HEC Kohonen uses the Mahalanobis distance to learn elongated shapes (typical of sonar data) and obtain a stochastic measurement of data-node association. The number of nodes is regulated by measuring how well a node model matches its associated data. The HEC Kohonen can handle high-dimensional problems and can be generalized to other pattern recognition problems. The JUKF compliments the HEC Kohonen in that it performs low-level (nonlinear) tracking more efficiently and more accurately than the extended Kalman filter. By estimating and propagating error covariances through system transformations, the JUKF eliminates the need to derive Jacobian matrices. The inclusion of stochastic information inherent to the HEC map renders the JUKF an excellent tool for our HEC-based map building, position estimation, motion planning and low-level tracking. C2 - 1998/// C3 - Proceedings - IEEE International Conference on Robotics and Automation DA - 1998/// DO - 10.1109/ROBOT.1998.677301 VL - 2 SP - 1405-1410 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0031637149&partnerID=MN8TOARS ER - TY - JOUR TI - Evaluation of AGV routeing strategies using hierarchical simulation AU - Seifert, RW AU - Kay, MG AU - Wilson, , JR T2 - INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH AB - To analyse an automated guided vehicle (AGV) system operating under selected vehicle routeing strategies, we present a simulation model that can handle an arbitrary system layout as well as arbitrary numbers of AGVs and pedestrians causing congestion in the system. We introduce a dynamic vehicle routeing strategy based on hierarchical simulation that operates as follows: at the time of each AGV routeing decision in the main simulation, subordinate simulations are performed to evaluate a limited set of alternative routes in succession until the current routeing decision can be finalized and the main simulation resumed. A case study involving a prototype AGV system operating under the control of a global vision system illustrates the advantages not only of this strategy but also of global-vision-based control. DA - 1998/7// PY - 1998/7// DO - 10.1080/002075498193057 VL - 36 IS - 7 SP - 1961-1976 SN - 0020-7543 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0032121916&partnerID=MN8TOARS ER - TY - JOUR TI - Decision support system for lumber procurement and dry kiln scheduling AU - Huang, J. C. C. AU - Culbreth, C. T. AU - Joines, J. A. AU - King, R. E. AU - Hodgson, T. J. T2 - Forest Products Journal DA - 1998/// PY - 1998/// VL - 48 IS - 9 SP - 51-59 ER -