• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.31
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• pp.21-31
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• 1994

In this research, tool allocation methods are studied in conjunction with loading and muting in FMSs. The objective function is to minimize production time while maximizing machine utilization of the FMS with several constraints. The proposed method has 2 steps. The first step is to determine tool allocation type with the proposed tool allocation method. The second step is to design loading models with routing. The effectiveness of the proposed FMS operation procedure is shown through numerical examples.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.77-79
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• 2011

과거 해양사고분석은 해양사고관련자의 증언이나 해도, 갑판로그북 등 해양사고관련자가 직접 작성한 서류 및 선교에서 기록되는 기관사용 기록 및 침로 기록 등 일부 자료만을 이용하여 분석하였다. 근래 VTS 항행기록 및 VDR 탑재가 강제화 되면서 더 많은 판단자료가 제공되고 있다. 본 연구에서는 FMSS를 이용하여 해양사고의 분석을 더 효율적으로 수행하는 방법을 제시하고 과거의 충돌사고를 이러한 방법으로 분석하였다. 해양사고의 효율적인 분석을 통하여 해양사고 저감방안을 수립하는데 유용한 수단이 될 것이다.

• IE interfaces
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• v.1 no.2
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• pp.25-34
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• 1988

Simulation is known to be a valuable tool for design and operation of Flexible Manufacturing Systems(FMSs) under study. However, in order for simulation to be useful, lots of knowledges about the behavior of system to be designed, statistics for output analysis, modeling techniques and a specific simulation language are required by the simulationist. In this paper a way to build simulation support system for nonexperts at simulation will be described and a simulation support system for FMS design and operation developed by the authors will be demonstrated.

• Corrosion Science and Technology
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• v.13 no.2
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• pp.41-47
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• 2014

The isothermal corrosion tests of several types of stainless steels, Ni-based alloys, and ferritic-martensitic steels (FMS) were carried out at the temperature of 550 and $650^{\circ}C$ in SFR S-$CO_2$ environment (200 bar) for 1000 h. The weight gain was greater in the order of FMSs, stainless steels, and Ni-based alloys. For the FMSs (Fe-based with low Cr content), a thick outer Fe oxide, a middle (Fe,Cr)-rich oxide, and an inner (Cr,Fe)-rich oxide were formed. They showed significant weight gains at both 550 and $650^{\circ}C$. In the case of austenitic stainless steels (Fe-based) such as SS 316H and 316LN (18 wt.% Cr), the corrosion resistance was dependent on test temperatures except SS 310S (25 wt.% Cr). After corrosion test at $650^{\circ}C$, a large increase in weight gain was observed with the formation of outer thick Fe oxide and inner (Cr,Fe)-rich oxide. However, at $550^{\circ}C$, a thin Cr-rich oxide was mainly developed along with partially distributed small and nodular shaped Fe oxides. Meanwhile, for the Ni-based alloys (16-28 wt.% Cr), a very thin Cr-rich oxide was developed at both test temperatures. The superior corrosion resistance of high Cr or Ni-based alloys in the high temperature S-$CO_2$ environment was attributed to the formation of thin Cr-rich oxide on the surface of the materials.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.3
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• pp.294-300
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• 2017

In this study, a survey was conducted among students who received ARPA/radar simulation training in order to verify the effect of training. An effective training method based on the analysis results was also proposed. Furthermore, this study analyzed full mission simulation conducted over one semester, and found that training effect increased as time passed. The survey showed improvement in skills related to radar/ARPA utilization, ARPA decoding, ship handling, and overall skill. Students responded practical skills improved more than theoretical knowledge, and also analysis showed that ship handling skills had a larger effect than radar decoding skills on improving overall skill, therefore proposed that theoretical education regarding the functions of radar and ARPA should be reinforced in ARPA/radar simulation training.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.4
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• pp.63-73
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• 1998

With the success of flexible manufacturing systems(FMSs), flexible assembly systems(FASs) have been developed to automatic factories further. As in a cellular FMS, a celluar FAS is considered as the most flexible and feasible assembly systems configuration. This paper presents a method for the integrated layout design in cellular FASs. Unlike the traditional paper, this paper deals with the formation of cells and the layout of cells for jobs with operation times on different machines. The procedure in this paper consists of two distinct phases. The first phase presents machine arrangement in a double rows flowline. cell formation not to allow intercellular movements, and integrated layout design in cellular FASs considering the characteristics of FAS, layout, and production factors This phase uses older optimal algorithm. The second phase proposes to balance the system with an objective of reducing the degree of workload deviation in the cells. Simulated annealing method is used to balance the system. This phase also shows the integrated layout design in cellular FASs with the cost less than total cost of the first phase.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.2
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• pp.31-37
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• 2003

In these days, several bridges have been built or under construction over navigational channel in Korea. In these cases there must be careful consideration for the marine safety of vessels to be passed by below the bridge. This paper aims to analyze the factors influencing maritime traffic safety and to figure out ample width of main span of these kinds of bridges through the reference study and FMSS.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.4
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• pp.175-187
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• 2004

We consider the simultaneous selection of part routes for multiple part types in Flexible Manufacturing Systems (FMSs). Using an optimization framework we investigate two alternative route assignment policies. The one, called routing mix policy in the literature, specifies the optimal proportion of each part type to be produced along its alternative routes, assuming that the proportions can be kept during execution. The other one, which we propose and call pallet allocation policy, partitions the pallets assigned to each part type among the routes. The optimization framework used is a nonlinear programming superimposed on a closed queueing network model of an FMS which produces multiple part types with distinct repeated visits to certain workstations. The objective is to maximize the weighted throughput. Our study shows that the simultaneous use of multiple routes leads to reduced bottleneck utilization, improved workload balance, and a significant increase in the FMS's weighted throughput, without any additional capital investments. Based on numerical work, we also conjecture that pallet allocation policy is more robust than routing mix policy, operationally easier to implement, and may yield higher revenues.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.786-789
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• 2000

제품의 설계, 생산, 운영/제어과정에서의 신속화, 고효율화, 저비용 등을 실현하기 위한 방법으로서 가상생산이 일반화되고 있다. 즉, 생산활동의 전 분야에 걸쳐서 인간의 의사결정을 신속하고 정확하게 할 수 있도록 지원하는 환경인 것이다. FMS 분야에서도 FMS 설계, 제어 및 운영단계에서 이와 같은 가상생산 개념이 적용될 수 있다. 컴퓨터 시뮬레이션을 이용한 FMS 설계분석은 이러한 대표적인 예이다. 본 연구에서는 FMS 운영단계에서 FMS 운영자에 의하여 사용되는 FMS 시스템 컨트롤러에 대하여 가상생산 개념을 적용하여 실제의 FMS 없이 FMS 운전과 스케줄링을 모의로 실행할 수 있는 FMS 가상 시스템 컨트롤러를 개발한 내용과 이의 활용에 대하여 간략하게 소개하고자 한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.38
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• pp.147-157
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• 1996

전통적인 원가계산 시스템에서 원가의 정확성은 생산량의 증감에 다라 변동하는 제조간접비에 의존하게 되며, 원가 배부기준은 대부분 생산하고 있는 제품의 수량과 밀접하다. 그러나, FMS 혹은 CIM등의 고도로 발달한 제조환경에서의 제조간접비는 반드시 생산량에 비례하지 않는다. 즉, 제품원가 구조변화 및 생산의 복잡성과 다양성에 따른 기업환경 변화 등이 주원인이 될 수 있다. 따라서 본 연구에서는 ABC 원가계산 시스템과 LP Model에 의한 전통적인 원가계산 방식과는 다른 ABC 원가계산 시스템을 만들었으며, 원가 활동동인에 따라 생산성 및 생산성 향상, 최적투자 활동 등을 수행할 수 있는 FMS 생산시스템의 최적평가 Model을 구축하였다.