• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.63-71
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• 2006

In this paper, we consider a planning problem arising from printed circuit board manufacturing industries. Given a set of several types of PCBs, component feeders and surface mounting machines in series in a PCB assembly line, the problem is to define the feeder allocation and job sequence with the objective of minimizing the total operation time of the line. We formulate the problem as a mathematical model. And, the problem is proven to be NP-hard, so a genetic algorithm is developed. Finally, we give test results to evaluate the performance of the genetic algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.1
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• pp.1-16
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• 1994

In this paper, we try to raise the efficiency of PCB production by improving automated inserting process. This process is composed of part inserting sequence and feeder allocation problem. Until now, this problem is formulated by Traveling Salesman Problem (TSP) or Rural Postman Problem. They concerted more on parts(chips) inserting. But in this paper, we concentrate on Feeder. We formulate 0-1 Integer program (MP2) easier than TSP. This program can be solved by using LP Package (i. e. LINDO, GAMS etc). We propose Heuristic algorithm ISFA which guarantees a local optimum and often gives solution. We give some examples to prove ISFA algorithm.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.363-365
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• 1991

This paper presents a method for feeder reconfiguration in order to operate distribution systems efficiently using heuristic rules. The reconfiguration method presented here not only eliminates various abnormal states but also achieves minimum power loss and optimum load balance of the distribution feeders under normal operating condition transfering loads from one feeder to anoter applying the experiences of the experts. To implement the method effectively, a best-first tree searching strategy based on heuristics is used to evaluate the various load transfer alternatives. The development of a rule-based system aimed at the reduction of the search space is presented as a means of implementing the best-first searching strategy. The results of the computer simulation of the above procedure are as follows; 1) achieving minimum power loss of the distribution feeder adopting the optimum load transfer alternative. 2) Enhencing system reliability and achieving load balance through rational allocation of the feeder loads.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.165-171
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• 2006

The appearance of over 10,000 TEU containerships (so called Mega-containerships) is determined. In order to operate these ships effectively, the number of these calling ports will diminish, and then feeder ships will transport cargoes from the hub-ports where mega-containerships call to the destination ports. In the hub-ports, handling containers for mega-containerships become huger, thus it is important for terminals to deal with cargo handling as soon as possible. However, the present terminal layout might have the limitation of maximum throughput per time unit. And then the transit time at the ports become longer. Therefore, we investigate the effect on some different terminal layouts with new alternatives. Actually, we discuss the ship-to-berth allocation at some adjacent berths for mega-containerships on three types of terminal layouts. First one is the conventional type consisted by some linear berths, most container terminals in the world are normally this type. Second one is the indented type consisted by linear berths and indented berths which we can handle from both sides of mega-containership simultaneously. Third one is the floating type consisted by linear berths and the floating berth. On this type, mega-containerships can moor between linear and floating berths. The merits of this type are that we can also handle from both sides of mega-containerships simultaneously, and ships can go through between linear berth and floating berths. Thus it is easier for ships to moor and leave berths. Under such assumptions, we examine the numerical experiments. In most cases, the total service times on the indented type are the longest among three types, these on the floating type are the next longer. Those reasons are that these layouts have the differences of berth occupancy obtained by the time and space axes, and whether the precedence constraints of ship service order needs or not.

• The Journal of the Korea Contents Association
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• v.6 no.4
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• pp.46-54
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• 2006

We propose an optimization method for PCB assembly lines including multiple surface mounters. To increase the productivity of PCB assembly line, the component allocation, feeder assignment, and assembly sequence of each surface mounter should be optimized. The optimization Problem is formulated as an integer programming problem. We divide the overall problem into two hierarchical sub-problems: forward-path problem and backward-path problem. The clustering algorithm and branch-and-bound algorithm are applied to solve the forward-path problem. The assignment algorithm and connection algorithm are applied to solve the backward-path problem. Simulation results are presented to verify the usefulness of the proposed method.

• Journal of the Korean Institute of Navigation
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• v.15 no.3
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• pp.13-24
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• 1991

This paper aims to determining the optimal capacity of Pusan port in view point of Container Physical Distribution cost. It has been established a coast model of the container physical distribution system in Pusan port is composed of 4 sub-systems and in-land transport system. Cargo handling system, transfer & storage system and in-land transport system, and analyzed the cost model of the system. From this analysis, we found that the system had 7 routes including in-land transport by rail or road and coastal transport by feeder ship between Pusan port and cargo owner's door. Though railway transport cost was relatively cheap, but, it was limited to choose railway transport routes due to the introducing of transport cargo allocation practice caused by shortage of railway transport capacity. The physical distribution ost for total import & export container through Pusan port was composed of 4.47% in port entring cost, 12.98% in cargo handling cost, 7.44% in transfer & storage cost and 75.11% in in-land transport cost. Investigation in case of BCTOC verified the results as follows. 1) The optimal level of one time cargo handling was verified 236VAN (377TEU) and annual optimal handling capacity was calculated in 516, 840VAN(826, 944TEU) where berth occupancy is $\rho$=0.6 when regardless of port congestion cost, 2) The optimal level of one time cargo handling was verified 252VAN (403TEU) and annual optimal handling capacity was calculated in 502, 110VAN (803, 376TEU) where berth occupancy is $\rho$=0.58 when considering of port congestion cost.