Browsing by Author "Chang, Ping-Chen"

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Bi-objective optimization for a multistate job-shop production network using NSGA-II and TOPSIS
(2019-07-01)
Lin, Yi-Kuei
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Chang, Ping-Chen
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Yeng, Louis Cheng-Lu
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Huan, Shang-Fu
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工業工程與管理學系
A job-shop production system (JPS) is a manufacturing system wherein each workstation configures multiple types of machines to produce small batches of a variety of products. In each workstation of a JPS, the number of machines that operate normally exhibits multiple levels of capacity owing to failures, partial failures, and maintenance. That is, the number of normal machines in each workstation is stochastic (i.e., multistate). To analyze such a JPS, the JPS is transformed into a multistate job-shop production network (MJPN) using a network topology. For the MJPN, a critical issue is to maximize the network reliability and to minimize the purchase cost when setting up the JPS. To achieve such bi-objective optimization, a machine vector (MV) representing the current number of normal machines in each workstation is introduced to evaluate network reliability. An algorithm based on a depth-first search (DFS) with an expanding technique is proposed to search all MVs for satisfying demand. Subsequently, to obtain a machine configuration (MF) simultaneously having the maximal network reliability and the minimal purchase cost, a two-stage approach is developed based on the non-dominated sorting genetic algorithm II (NSGA-II) and the technique for order of preference by similarity to ideal solution (TOPSIS). A real case of t-shirt production is utilized to illustrate the proposed method.
Low-Trigger ESD Protection Design with Latch-Up Immunity for 5-V CMOS Application by Drain Engineering
(2017-01-01)
Chiang, Chun
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Chang, Ping-Chen
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Chao, Mei-Ling
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Tang, Tien-Hao
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Su, Kuan-Cheng
According to previous work about PESD optimization [1], there are some potential risks such as low breakdown voltage (V-BD) and low holding voltage (V-h) can be improved for power-rail ESD application. Through drain region design with P-type concentration engineering, the enclosed P-Well in Deep N-Well (EW) in drain region was proposed with high ESD performance (HBM>8kV) and good turn-on efficiency (V-t1=8.1V) without suffering from low V-BD and latch-up issues.
Reliability of time-constrained multi-state network susceptible to correlated component faults
(1970-01-01)
Lin, Yi-Kuei
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Fiondella, Lance
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Chang, Ping-Chen
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工業工程與管理學系
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Department of Industrial Engineering and Management
Correlation can seriously degrade reliability and capacity due to the simultaneous failure of multiple components, which lowers the probability that a system can execute its required functions with acceptable levels of confidence. The high cost of fault in time-critical systems necessitates methods to explicitly consider the influence of correlation on reliability. This paper constructs a network-structured model, namely time-constrained multi-state network (TCMSN), to investigate the capacity of a computer network. In the TCMSN, the physical lines comprising the edges of the computer network experience correlated faults. Our approach quantifies the probability that d units of data can be sent from source to sink in no more than T units of time. This probability that the computer network delivers a specified level of data before the deadline is referred to as the system reliability. Experimental results indicate that the negative influence of correlation on reliability could be significant, especially when the data amount is close to network bandwidth and the time constraint is tight. The modeling approach will subsequently promote design and optimization studies to mitigate the vulnerability of networks to correlated faults.
System reliability estimation and sensitivity analysis for multi-state manufacturing network with joint buffers-A simulation approach
(2019-08-01)
Chang, Ping-Chen
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Lin, Yi-Kuei
;
Chiang, Yu-Min
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工業工程與管理學系
;
Department of Industrial Engineering and Management
This paper proposes a simulation approach to estimate system reliability of a multi-state manufacturing network (MSMN) with joint buffers. The system reliability is an indicator to evaluate the probability that an MSMN can provide sufficient capacity to meet a given demand. From the perspective of industrial and systems engineering, the MSMN is constructed as a network topology in which each node denotes an inspection point and arcs denote workstations. In particular, joint buffers with finite volume are embedded in such a topology. Based on the topology, workload processed by each workstation is derived according to a given demand. Subsequently, a simulation approach is applied to randomly generate the current capacity state for the MSMN and to compute the buffer usage under such a state. System reliability is estimated after several iterations of simulation to check if the generated capacity state is available to process the workload or not. Besides, sensitivity analysis is adopted to investigate the most potential location to increase buffer volume. Two practical examples are adopted to validate the effectiveness of the proposed simulation approach. Experimental results show that using joint buffers is more reliable than using parallel buffers in separated production lines.