• Proceedings of the Korea Society for Simulation Conference
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• 1999.04a
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• pp.100-104
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• 1999

실제 생산공장에서 행해지는 작업 방법이나, 제조 과정을 사전에 보여질 수 있다면 작업 환경에서 일어나는 문제점 등을 미리 예측 할 수도 있고, 공간활용 및 효율적인 운영이 가능할 것이다. 본 연구는 주어진 공장 내에서 최적 배치를 위한 물류의 이동 및 적재 시스템 구축을 위한 단계로써 기존의 P업체를 대상으로 가상 공장 Simulation 시스템을 구축하였다. 가상 공장 시스템은 VR(Virtual Reality)기법을 적용하여 생산 과정 모습을 재현하도록 구현하였다. 가상 공장을 구축하여 기존 공장의 문제점을 지적하고 효율적인 운영을 위한 방안을 제안하였으며 각 부서별 재배치도 제안하였다. 구현된 가상공장은 트윈기, 인플레이션기, 인쇄기 등으로 구성되며, 생산 공정의 가상 시뮬레이션을 통하여 실제 생산라인 및 장비의 효율성을 평가하였고 생산 과정을 수행하여 신 방비의 사용 여부를 분석할 수 있었다.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.191-197
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• 2023

The purpose of the study was to provide an educational environment for designing and producing virtual reality practice contents that can be used in semiconductor production lines and clean rooms. Through this process, the user can acquire practical knowledge through experiences close to reality, such as experiencing the main semiconductor solar cell manufacturing facilities as well as procedural knowledge before and after entering the clean room.. In particular, it provides users with an immersion experience close to reality by creating an environment for experiential content necessary for semiconductor and solar cell manufacturing processes and clean room entrance procedure experiential content, which is expected to improve education immersion, realism, cost, efficiency, and education satisfaction. Depending on the characteristics of Dangerous, Impossible, Counter-productive etc, immersive content makes learners immersed in the learning content, induces proactive/active learning, and embodies the learning content, resulting in positive results in the field of improving educational effectiveness.

• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.11-24
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• 2012

We compared a DBR(drum-buffer-rope) system with a CONWIP(constant work-in-process) system in a production line with constant processing times. Based on the observation that a WIP-controlled line production system such as DBR and CONWIP is equivalent to a m-node tandem queue with finite buffer, we applied a max-plus algebra based solution method for the tandem queue to evaluate the performance of two systems. Numerical examples with 6 workstations were also used to demonstrate the proposed analysis. The mathematical analyses support that CONWIP outperforms DBR in terms of expected waiting time and WIP. Unlike the CONWIP case, sequencing workstations in a DBR affects the performance of the system. Delaying a bottleneck station in a DBR reduces expected waiting time.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.50-50
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• 2010

최근 토요타 자동차의 대량 리콜 사태로 안전과 관련된 자동차 품질에 대한 관심과 중요성이 크게 부각되었다. 본 연구에서는 나날이 높아지고 있는 자동차 품질 기준과 생산 비용 절감, 공정 자동화 요구에 부응하기 위한 차체 저항 점 용접부 품질 검사 자동화 기술 개발을 위해 적용 가능한 센서들을 비교, 검토하였다. 알려진 비파괴 검사 방법은 초음파, 와전류, 방사선 검사법 등 다양한 방법들이 존재하지만, 이 연구에서는 생산 라인 현장 적용이 가능한 소형 센서들을 중심으로 검토 영역을 제한하였다. 검토된 비파괴 검사 방법은 총 5가지 종류로 종래의 수동 초음파 검사법, 집적된 탐촉자를 이용한 3차원 초음파 검사법, NAUT(Non-contact Air-coupled Ultrasonic Test), EMAT(EletroMagnetic Acoustic Test), 그리고 너겟 프로파일러$^{TM}$이다. 이 연구에서는 각 검사법의 원리와 장단점을 설명하고 생산 라인 적용에 필요한 필수 항목들에 대해 고찰하였다.

• The Journal of Bigdata
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• v.7 no.1
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• pp.99-111
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• 2022

A simulation technique can be used to analyze performance measures and support decision makings in manufacturing systems considering operational uncertainty and complexity. The simulation requires an input modeling procedure to reflect the target system's characteristics. However, data collection to build a simulation is quite limited when a target system includes manual productions with a lot of operational time such as construction equipment assembly lines. This study proposes a procedure for simulation input modeling using video data when it is difficult to collect enough input data to fit a probability distribution. We conducted a video-data analysis and specify input distributions for the simulation. Based on the proposed procedure, simulation experiments were conducted to evaluate key performance measures of the target system. We also expect that the proposed procedure may help simulation-based decision makings when obtaining input data for a simulation modeling is quite challenging.

• Transactions of the KSME C: Technology and Education
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• v.3 no.1
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• pp.45-53
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• 2015

The fact that gas hydrate and/or paraffin wax is frequently plugged in offshore pipeline has been become very significant for offshore piepline flow assurance. An active electrical heating along pipeline has adapted in resolving flow assurance problem like as gas hydrate and wax plugging. This study represents a novel internal-swirled heater which was designed and fabricated for more effective heating and thermal mixing through pipeline. The internal-swirled heater suggested in this study shows higher thermal mixing performances than the conventional external-traced heater.

• The Journal of Bigdata
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• v.7 no.1
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• pp.75-87
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• 2022

This study investigates a dynamic flexible flow shop scheduling problem under uncertain rework operations for an automobile pipe production line. We propose a weighted dispatching rule (WDR) based on the multiple dispatching rules to minimize the weighted sum of average flowtime and tardiness. The set of weights in WDR should be carefully determined because it significantly affects the performance measures. We build a discrete-event simulation model and propose a genetic algorithm to optimize the set of weights considering complex and variant operations. The simulation experiments demonstrate that WDR outperforms the baseline dispatching rules in average flowtime and tardiness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8940-8947
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• 2015

Mixed-model assembly line has been widely used in automotive assembly industry to quickly respond the diverse product demands. But, this model can lead to part confusion, which is a source for assembly errors when parts are physically interchangeable in a mixed-model assembly line. With the recent application of new technologies such as radio frequency identification (RFID) and ZigBee wireless sensor network (WSN) to the assembly process, real-time information has become available in this manufacturing systems through IT infrastructures. At first, this paper presents an RFID application for assembly processes, specifically, for a mixed-model assembly line. Thus, to ensure that parts be picked accurately, each cockpit module on the assembly line is attached with a RFID tag and the tag is scanned using a RFID reader and recognizes the vehicle, and each part of the cockpit module is attached with a barcode and the barcode is scanned by a barcode reader and each part is identified correctly for the vehicle. Second, this paper presents a ZigBee wireless sensor network (WSN) protocol-based application for a reconfigurable mixed-model assembly line of cockpit module to reduce the assembly errors and the cost of the change/reconfiguration on the assembly lines due to the various orders and new models from the motor company, avoiding the wiring efforts and inconvenience by wiring between the several RFID devices and the IT server system. Finally, we presents the operation results for several years using this RFID/ZigBee wireless sensor network (WSN) protocol-based cockpit module assembly line.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.183-192
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• 2022

With the growth of the packaging industry, demand on the packaging printing comes in various forms. Customers' orders are diversifying and the standards for quality are increasing. Offset printing is mainly used in the packaging printing since it is easy to print in large quantities. However, productivity of the offset printing decreases when printing various order. This is because it takes time to change colors for each printing unit. Therefore, scheduling that minimizes the color replacement time and shortens the overall makespan is required. By the existing manual method based on workers' experience or intuition, scheduling results may vary for workers and this uncertainty increase the production cost. In this study, we propose an automated scheduling method of parallel offset printing process for packaging printing. We decompose the original problem into assigning and sequencing orders, and ink arrangement for printing problems. Vehicle routing problem and assignment problem are applied to each part. Mixed integer programming is used to model the problem mathematically. But it needs a lot of computational time to solve as the size of the problem grows. So guided local search algorithm is used to solve the problem. Through actual data experiments, we reviewed our method's applicability and role in the field.

• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.227-239
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• 1999

본 연구에서는 부서간 갈등을 해결하기 위한 새로운 방법론으로서 웹 기반 협상지원시스템 (Web-based Negotiation Support System: Web NSS)을 제안한다. 기업의 경영활동에 있어서 각 부서간에는 여러 가지 이유로 인해 갈등이 존재한다. 대표적으로 생산부서와 마케팅 부서간에는 갈등이 항상 존재하기 마련이다. 예를 들어, 마케팅 부서에서는 수시로 변하는 고객들의 요구사항에 맞추기 위해서 제품라인을 확대하여 다양한 제품들을 생산하고, 그에 따른 높은 판매실적을 원한다. 그러나, 생산부서에서는 이와는 달리 적은 종류의 제품을 가능한한 한정적으로 생산하여 제품에 들어가는 원가를 절감하고 그에 따라서 생산실적을 높이려고 한다. 이 같은 유형의 부서간 갈등은 결과적으로 기업의 전체적인 성과를 저해시키는 요인으로 작용한다. 또한, 최근 대부분의 기업은 각각의 부서별 기능을 분산형태로 운영하고 있어서 관련부서가 지리적으로 멀리 떨어져 있게 되어 새로운 의사결정통합 지원시스템이 절실히 요구된다 본 연구에서는 이러한 상황에 적합한 새로운 유형의 갈등관리 메커니즘으로서 웹 기반 협상지원시스템을 제안한다. 본 시스템은 생산부서와 마케팅부서간의 갈등을 해결하고 이를 협상의 형태로 지원하기 위한 웹 기반 의사결정지원시스템이다. 본 연구에서는 실험과정을 통하여 제안하는 의사결정지원시스템의 성과를 증명하였다.