• 한국CDE학회논문집
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• 제17권4호
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• pp.274-281
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• 2012

This paper proposed a control simulation method for design and verification of the transport system in an automobile assembly line based on digital manufacturing system. The design of the transport system involves two major activities: mechanical design (device specification) and electrical design (device behavior and system control). Conventionally, the simulation and emulation system of the transport system focuses on the abstract level, which mainly deals with design verification, alternative comparison, and system diagnosis. Although it can provide overall system visibility in monitoring how well it works in the process and view, its simulation models are not sufficiently realistic to be used for a detailed design or for implementation purposes. In this paper, a digital simulation model for a transport system in an automotive assembly line is constructed by adapting a digital manufacturing methodology. We use the concept of the "Virtual Probe", which transport a carrier instead of the belt of the conveyor. In conclusion, the proposed method is valuable in the process of test run in the shop floor. This method would reduce the time and effort for validating the manufacturing system and improve the productivity and integrity of the control program.

• 산업공학
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• 제12권1호
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• pp.121-131
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• 1999

In this article, a simulation model of a microwave oven assembly line is developed to identify system parameters to improve the system performances such as work-in-process inventories, production lead time, mean earliness, mean tardiness and in-time completion rate. System parameters investigated include dispatching rules, lot sizing, setup time reduction, demand increase, productivity improvement, production scheduling, hardware characteristics, etc. The model has been developed using SIMAN simulation language which has been demonstrated to be a powerful tool to simulate complex manufacturing systems. We have suggested the results obtained to improve the system performances of an existing production line.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.453-457
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• 2005

Existing manufacturing system has consumed too much energy, space and resource in micro parts manufacturing. To improve this, micro factory system is suggested. But it is difficult to get the high reliability in the assembly, production and inspection of the minute parts because the construction of the micro factory has been started just before. In this study, we will build the digital manufacturing simulation on the micro factory's process and verify the production and assembly process using this simulation.

• 한국CDE학회논문집
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• 제14권4호
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• pp.225-233
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• 2009

The objective of this paper is to examine a construction method and verify PLC logic using the logical modeling and simulation of a virtual plant has complex manufacturing system and the domain of application is car body assembly line of automotive industrial operated by PLC Program. The proposed virtual plant model for the analysis of the construction method consists of three types of components which are virtual device, intermediary transfer and controller is modeled by logical model but it the case of the verification of PLC program, HMI and PLC logic in the field substitute for the controller. The implementation of the proposed virtual plant model is conducted PLC Studio which is an object-oriented modeling language based on logical model. As a result, proposed methods enable 3D graphics is designed in the analysis step to use for verification of PLC program without special efforts.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.637-643
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• 2022

Uranium and plutonium are required to be accounted in spent fuel head-end and major recovery area in pyro-process for safeguards purpose. The possibility of neutron resonance technique, as a nondestructive analysis, was simulated on isotopic fissile analysis for large scale process. Neutron resonance technique has advantage to distinguish uranium from plutonium directly in mixture. Simulation was performed on U235 and Pu239 assay in spent fuel and for scoping examination of assembly type. The resonance energies were determined for U235 and Pu239. The linearity in the neutron transmission was examined for the selected resonance energies. In addition, the limit for detection was examined by changing sample density, thickness and content for actual application. Several factors were proposed for neutron production and the moderated neutron source was simulated for effective and efficient transmission measurement. From the simulation results, neutron resonance technique is promising to analyze U235 and Pu239 for spent fuel assembly. An accurate fissile assay will contribute to an increased safeguards for the pyro-processing system and international credibility on the reuse of fissile materials in the fuel cycle.

• 산학경영연구
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• 제13권
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• pp.263-273
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• 2000

벤츠(현 다임-클라이슬러)자동차회사는 새로운 공장을 미국 앨라배마 주 Vance 지역에 건설하고 이곳 공장으로부터 스포츠-레저용의 4륜 구동 M-class 자동차를 생산하고 있다. 이 벤츠공장의 생산라인은 차체형성공정, 도장공정, 그리고 엔진조립 공정으로 나누어져 있고 이들 생산라인사이에는 한 라인에서의 고장(down)이 다른 라인에 파급되지 않도록 완충라인(Buffer)이 설치되어 있다. 본 연구의 목적은 일정한 비율의 고장률을 각 생산라인에 적용시켰을 때 주어진 생산목표(270대)를 달성할 수 있는지, 만약 달성할 수 없다면 가장 문제가 되는 생산라인은 어디인지, 또 생산라인 사이에 존재하는 완충라인이 어느 정도의 완충역할을 하는지, 최적의 생산능력을 유지하기 위한 완충라인의 크기는 어느 정도인지 등, 각종 생산라인의 운영지침(operation policy)들을 시뮬레이션 기법을 이용하여 탐색한 후 병목생산시설(bottleneck)을 찾아내는 것이다. 본 연구를 위한 시뮬레이션 도구로는 ARENA를 이용했고 20일 간의 시뮬레이션 결과를 종합하여 분석하였다. 또 신뢰구간 95% 범위에서 각 생산라인의 최대 생산능력도 측정하여 실제 생산대수와의 차이를 규명할 수 있는 근거를 제공하였다.

• 한국압력기기공학회 논문집
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• 제12권1호
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• pp.11-16
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• 2016

Fuel assembly's mechanical characterization test facility (FAMeCT) in KAERI was constructed with upgraded functional features such as increased loading capacity, underwater vibration testing and severe earthquake simulation for extended fuel design guideline. This facility is designed and developed to provide out-pile fuel data for accident analysis model and fuel licensing. Functional tests of FAMeCT were performed to confirm functionality, structural integrity, and validity of newly-built fuel assembly mechanical test facility. Test program includes signal check of data acquisition system, load delivering capacity using real-sized fuel assemblies and a standard loading cylindrical rigid specimen. Fuel assembly's lateral bending test was carried out up to 30 mm of pull-out displacement. Limit case axial compression loading test up to 33 kN was performed to check structural integrity of UCPS (Upper Core Plate Simulator) support frame. Test results show that all test equipment and measurement system have acceptable range of alignment, signal to noise ratio, load carrying capacity limit without loss of integrity. This paper introduces newly constructed fuel assembly's mechanical test facility and summarizes results of functional test for the mechanical test equipment and data acquisition system.

• Nuclear Engineering and Technology
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• 제39권1호
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• pp.43-50
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• 2007

A partial flow blockage in an assembly of a liquid metal reactor could result in a cooling deficiency of the core. To develop a partial blockage detection system, we have studied the changes of the temperature fluctuation characteristics in the upper plenum according to changes of the t10w blockage conditions in an assembly. We analyzed the temperature fluctuation in the upper plenum with the Large Eddy Simulation (LES) turbulence model in the CFX code and evaluated its statistical parameters. Based on the results of the statistical analyses, we developed a neural network model for detecting a partial flow blockage in an assembly. The neural network model can retrieve the size and the location of a flow blockage in an assembly from a change of the root mean square, the standard deviation, and the skewness in the temperature fluctuation data. The neural network model was found to be a possible alternative by which to identify a flow blockage in an assembly of a liquid metal reactor through learning and validating various flow blockage conditions.

• 한국항공우주학회지
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• 제35권11호
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• pp.1036-1042
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• 2007

비행조종컴퓨터 하드웨어 개발은 상용 툴 및 전용 개발치구가 전무하여 전 근대적인 방법으로 개발하고 있어 개발 기간을 단축하기가 용이하지 않다. 모델링 및 시뮬레이션과 가상현실 기술을 이용하여 비행조종컴퓨터 하드웨어 개발에 적용하는 프로세스 개선 툴이 필요하게 되었다. 본 논문에서는 비행조종컴퓨터 입/출력 신호 흐름, 입력 신호의 고장모니터 및 고장 관리 알고리즘, 논리 회로의 작동, 회로기판 조립체의 형상 및 장착 등과 같은 비행조종컴퓨터의 설계특성을 가상의 공간에 시각화 하고 모사할 수 있는 프로세스 개선 툴을 제안한다. 프로세스 개선 툴 사용자는 open flight format의 3차원 모델링 데이터를 이용하여 구성된 비행조종컴퓨터 모델을 사용하여 회로기판 조립체까지 분해/조립을 할 수 있으며 다양한 비행조종컴퓨터 설계 형상을 시뮬레이션 할 수 있다.

• 대한안전경영과학회지
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• 제15권4호
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• pp.261-267
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• 2013

In automobile company it is needed to establish the collaborative relationship between the assembly company and the part manufacturing company. In this paper we established the improvement for the procurement logistics and logistics in assembly company and thus we derived the near optimal procurement cycle through the simple EXCEL simulation and the improved inventory management method for H automobile company in CHINA. At this time we adopted the pull manufacturing process instead of push manufacturing process. We resulted that the manufacturing activity of both companies was stabilized and the usage of storage area in assembly company was reduced by 50%, especially it was reduced by 100% in the case of directly delivering the parts to assembly line through the third party logistics company.