The Experts below are selected from a list of 50628 Experts worldwide ranked by ideXlab platform
Julie M. Schoenung - One of the best experts on this subject based on the ideXlab platform.
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A test-rework process yield performance model for estimation of printed wiring board Assembly Cost
International Journal of Production Economics, 2009Co-Authors: Koki Shimohashi, Xiaoying Zhou, Julie M. SchoenungAbstract:This paper proposes a new test-rework process yield performance (TRePYP) model, combined with an Assembly Cost estimation algorithm, for an accurate representation of current practice in printed wiring board (PWB) Assembly, especially in the design phase. The model captures the "dedicated" feature of PWB Assembly activities and, instead of adopting lumped parameters, utilizes easy-to-measure process parameters so that both Assembly performance and Assembly Cost can be evaluated. In the case study, changes in Assembly Cost due to lead-free conversion are estimated. Care is taken to ensure that the TRePYP method can account for both quality degradation issues and changes in the test-rework workload.
Morteza Bagheri - One of the best experts on this subject based on the ideXlab platform.
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Risk assessment framework for the rail transport of hazardous materials formulation and solution
Transportation Research Record, 2014Co-Authors: Mohadeseh Rahbar, Morteza BagheriAbstract:This research presented a unique opportunity to investigate an innovative train Assembly process to mitigate the risks associated with the rail transport of hazardous materials (hazmat). This paper presented the formulation and solution of a risk assessment framework for moving hazmat by rail transport. The databases of FRA have been used to develop a risk minimization model for application that incorporates in-transit risk as well as rail yard train Assembly Cost and time constraints. The research problem was formulated as a mixed integer programming problem to be solved with the CPLEX software. The merits of the proposed model were illustrated through a case study highlighting the inadequacies of previous studies.
Koki Shimohashi - One of the best experts on this subject based on the ideXlab platform.
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A test-rework process yield performance model for estimation of printed wiring board Assembly Cost
International Journal of Production Economics, 2009Co-Authors: Koki Shimohashi, Xiaoying Zhou, Julie M. SchoenungAbstract:This paper proposes a new test-rework process yield performance (TRePYP) model, combined with an Assembly Cost estimation algorithm, for an accurate representation of current practice in printed wiring board (PWB) Assembly, especially in the design phase. The model captures the "dedicated" feature of PWB Assembly activities and, instead of adopting lumped parameters, utilizes easy-to-measure process parameters so that both Assembly performance and Assembly Cost can be evaluated. In the case study, changes in Assembly Cost due to lead-free conversion are estimated. Care is taken to ensure that the TRePYP method can account for both quality degradation issues and changes in the test-rework workload.
Hyungsuck Cho - One of the best experts on this subject based on the ideXlab platform.
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A genetic-algorithm-based approach to the generation of robotic Assembly sequences
Control Engineering Practice, 1999Co-Authors: D.s. Hong, Hyungsuck ChoAbstract:Abstract An Assembly sequence is considered to be optimal when it minimizes the Assembly Cost while satisfying Assembly constraints. To generate such sequences for robotic Assembly, this paper proposes a method using a genetic algorithm (GA). This method denotes an Assembly sequence as an individual, which is assigned a fitness related to the Assembly Cost. Then, a population consisting of a number of individuals evolves to the next generation through the genetic operations of crossover and mutation, based upon the fitness of the individuals. The population continues to evolve repetitively, and finally the fittest individual with its corresponding Assembly sequence is found. Through case studies for industrial products such as an electrical relay and an automobile alternator, the effectiveness of the proposed method is demonstrated, and the performance is analyzed.
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Generation of robotic Assembly sequences with consideration of line balancing using simulated annealing
Robotica, 1997Co-Authors: D.s. Hong, Hyungsuck ChoAbstract:An Assembly sequence is considered to be optimal when the sequence satisfies Assembly constraints and yields the minimum Assembly Cost. While, a line balancing solution is considered to be optimal when the solution has the minimum idle time of the line, i.e. the minimum number of workstations for a given cycle time. Although optimal Assembly sequences are generated without considering line balancing, they may not guarantee the minimum number of workstations. In such case, additional Cost should be required to accommodate the increased number of workstations. Therefore, it is essential to consider line balancing in the generation of Cost-effective Assembly sequences. To generate such line-balanced Assembly sequences for robotic Assembly, this paper treats a single-model and deterministic (SMD) Assembly line balancing (ALB) problem, and proposes a new method using a simulated annealing. In this method, an energy function is derived in consideration of the satisfaction of Assembly constraints, and the minimization of Assembly Cost and the idle time. Then, the energy function is iteratively minimized and occasionally perturbed by a simulated annealing. When no further change in energy occurs, a solution of Assembly sequence with consideration of line balancing is finally obtained. To show the effectiveness of the proposed scheme, case studies are presented for industrial products such as an electrical relay and an automobile alternator.
Sukhan Lee - One of the best experts on this subject based on the ideXlab platform.
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backward Assembly planning with Assembly Cost analysis
International Conference on Robotics and Automation, 1992Co-Authors: Sukhan LeeAbstract:The author considers automatic Assembly planning by developing a backward Assembly planner which handles the case where an Assembly sequence is not the same as the reverse of a disAssembly sequence; improving planning efficiency with the reduction of search space by merging and grouping parts based on interconnection feasibility and special process precedence constraints; establishing Assembly process planning by incorporating such special processes as testing, cleaning, etc., in Assembly planning; and providing subAssembly evaluation criteria with a direct connection to Assembly Cost. A method for the stability and directionality of an Assembly is presented through which the required number of holding devices and reorientations during Assembly are identified. >
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Backward Assembly Planning Analysis with Assembly Cost
1992Co-Authors: Sukhan LeeAbstract:International confc~~~~~ m Robtics d Automatian Abstract This paper presents an Assembly planning system that op- erates based on a recursive decomposition of Assembly into subassemblies, and analyzes Assembly Cost in terms of sta- bility, directionality, and manipulability to guide the gener- ation of preferred Assembly plans. The planning in this system incorporates the special pro- cesses, such as cleaning, testing, labeling, etc. that must occur during the Assembly, and handles nonreversible as well as reversible Assembly tasks through backward assem- bly planning. In order to increase the planning efficiency, the system avoids the analysis of decompositions that do not correspond to feasible Assembly tasks. This is achieved by grouping and merging those parts that can not be decom- posable at the current stage of backward Assembly planning due to the requirement of special processes and the con- straint of interconnection feasibility. This paper also estab- lishes methods of evaluating Assembly Cost in terms of the number of fixtures (or holding devices) and reorientations required for Assembly, through the analysis of stability, di- rectionality, and manipulability. All these factors are used in defining Cost and heuristic functions for an AO* search for an optimal plan.
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ICRA - Backward Assembly planning with Assembly Cost analysis
Proceedings 1992 IEEE International Conference on Robotics and Automation, 1Co-Authors: Sukhan LeeAbstract:The author considers automatic Assembly planning by developing a backward Assembly planner which handles the case where an Assembly sequence is not the same as the reverse of a disAssembly sequence; improving planning efficiency with the reduction of search space by merging and grouping parts based on interconnection feasibility and special process precedence constraints; establishing Assembly process planning by incorporating such special processes as testing, cleaning, etc., in Assembly planning; and providing subAssembly evaluation criteria with a direct connection to Assembly Cost. A method for the stability and directionality of an Assembly is presented through which the required number of holding devices and reorientations during Assembly are identified. >
