• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.47-50
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• 2002

선반건조 일정계획에 있어서 탑재 공정은 전체 생산일정 계획 중 선박 한 척에 대한 계획의 시발점이 되며, 병목현상 등을 유발하여 다른 일정에 가장 큰 영향을 주게 되는 공정이다. 최근 많은 조선소에서 하나의 Dock 내에서 두 착 이상의 배를 동시에 건조하는 tandem 방식을 택하고 있어 dock 내의 한정된 Crane 의 개수와 Crane의 Capacity, 공수 등의 자원, 그리고 작업환경에서 일어날 수 있는 여러 가지 변수들을 제대로 고려하지 못 했을 시에는 일정의 차질과 Dock의 회전율을 떨어트리게 한다. 본 논문에서는 가상공간에 하나의 Dock 를 만들어서 일정계획에서 작성한 Network를 사용하여 실제 작업하게 해서 그 Network가 현장에서의 최적한가를 점검하게 하고 현장에서 수정하는 작업을 줄이게 하는 것의 방법으로 simulation을 개발하였다.

• 산업공학
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• 제15권4호
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• pp.382-390
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• 2002

This paper deals with planning of order-picking warehouse considering the batch order picking for transportation equipments to pick consumers' orders at a time among order-picking methods and a systematic approach method in order to analyze the order-picking warehouse which can perform optimal operation. To estimate an operating time of transportation equipments to carry out order-picking, this paper suggests three operations : first, to design the refrigerated warehouse using warehouse design parameters, second, to calculate the travel time of transporters considering four types of times with the probabilistic picking frequency, and third, to analyze an order-picking warehouse to construct a simulation model with the AutoMod as a simulation tool. We apply this model to a refrigerated warehouse company in Busan.

• 대한교통학회지
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• 제13권4호
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• pp.79-103
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• 1995

The elasticity of a model is considered most important. Without showing the proper elasticity any model cannot provide useful information for decision making. This paper demonstrates a macro model which can generate dynamic transport informations every 15 minutes. Without the Wardrop principles and the monotonicity assumptions for the link travel time and link volume relationship, the basic elements of this new modeling approache are composed of link density simulation, stochastic incremental route choice, departure time choice, destination choice and mode choice. The elasticity of the proposed model is examined based on elasticity equations and simulation results. Also the transferability from a mega city like Seoul to a big city like Daejon is demonstrated for the choice model. The issues centering around the dynamic relations among density(k), speed(u), and flow rate(v) are also discussed for the modeling of highly congested situations.

• 한국시스템다이내믹스연구
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• 제5권1호
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• pp.35-47
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• 2004

Analyzers adopt a variety of techniques in analyzing public policy. Based on the results of exploration, they explain problems and suggest prescriptions such as policy alternatives. By doing so, however, they have different degree of confidence in their own results according to what techniques they adopt. This study explores whether system dynamics apporach gives analyzers more confidence on their own simulation results than other approaches do. This study designed an experiment. Three research teams are organized. Each of them applies different analytic techniques on the same policy issue, i.e., introduction of transportation tax. It flnds that researchers using S,D. simulation technique are most confident on what they predict, while researchers adopting survey techniques show moderate degree of confidence on their results. Researchers using regression are least confident.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.163-170
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• 2002

The High Level Architecture(HLA) for modeling and simulation was developed as means of facilitating interoperability among simulations and promoting reuse of simulations and their components. The purpose of this paper is to provide a summary of the latest release of the HLA concept, supporting utilities and develop the prototyped Transportation Movement Management(TMM) federation. To obtain this goal, the Federation Development and Execution Process(FEDEP) is being applied to development of TMM federation will consist of three federates. This paper outlines the rationale of our approach, describes the application of the FEDEP in the development of the federation, and provides the current status of the federation development. The resulting federation shows complete interoperability among simulation components in the TMM federation and satisfactory simulation outputs. We present a description and process of the federation and the lessons learned with the process utilization for federation development and execution. Furthermore, the issues in establishing a HLA based federation across multiple legacy simulations are discussed.

• 대한인간공학회지
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• 제26권2호
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• pp.89-102
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• 2007

Generally, it is well known that driving in tunnel imposes large burden to driver because of spatial constraint, limited visual field and so on. And such a burden of driver result in high accident occurrence. In this reason, studies dealing with features of driving and traffic flow in tunnel have been performed. However, information about characteristics of drivers and traffic in a very long tunnel is not accumulated yet. The purpose of this study is to identify the relations between tunnel length and burden of driver, driving patterns, traffic flow characteristics using the tunnel simulator that realizing various tunnel situations. For this, the tunnel simulation program was developed along 11km-length section. And biological data of 10 subjects gained from driving condition in simulation program was analyzed and compared with the result of real driving condition.

• 대한산업공학회지
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• 제41권5호
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• pp.511-520
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• 2015

Inventory, cost, and the level of service are three interrelated key metrics that most supply chain organizations are striving to optimize. One way to achieve this goal is to create a simulation model to conduct sensitivity analysis and optimization on several different supply chain policies that can be implemented in actual operation. In this paper, a case of Xerox global supply chain modeling and analysis to assess several "what if" scenarios for the consumable policy safety stock is presented. The simulation model, combined with analytical cost model and optimization module, is used to optimize the policy safety stock level to achieve the lowest total value chain cost. It was shown quantitatively that the policy safety stock can be reduced, but it is offset by the inbound premium transportation cost to expedite supplies in shortage, and the outbound premium transportation cost to send supplies to customers via express shipment, requiring fine balance.

• 방사성폐기물학회지
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• 제19권1호
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• pp.61-74
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• 2021

A paradigm shift in the government's energy policy was reflected in its declaration of early closure of old nuclear plants as well as cancellation of plans for the construction of new plants. To this end, unit 1 of Kori Nuclear Power Plant was permanently shut down and is set for decommission. Based on these changes, the off-site transport of spent fuels from nuclear power plants has become a critical issue. The purpose of this study is to develop an optimized method for transportation of spent fuels from Kori Nuclear Power Plant's units 1, 2, 3, and 4 to an assumed interim storage facility by simulating the scenarios using the Flexsim software, which is widely used in logistics and manufacturing applications. The results of the simulation suggest that the optimized transport methods may contribute to the development of delivery schedule of spent fuels in the near future. Furthermore, these methods can be applied to decommissioning plan of nuclear power plants.

• 대한교통학회지
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• 제28권4호
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• pp.167-175
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• 2010

유비쿼터스 통신 및 센서네트워크 기술발전으로, 기존 ITS(Intelligent Transportation System) 환경에서 불가능했던 미시 교통류 정보의 수집 가공과 V2V(Vehicle-to-Vehicle), V2I(Vehicle-to-Infra) 양방 통신환경을 활용한 개별차량 및 차량군 단위의 미세제어가 가능해졌다. 이에, 유비쿼터스 기술진보에 맞춘 진일보된 교통운영기술로서 적정속도 관리 알고리즘을 제시하고 그 알고리즘의 성능과 효과를 평가하였다. 적정속도 관리 알고리즘은, 소통원활 상황에서 과속을 억제하고 개별운전자간 속도 편차를 최소화함을 목표로 하는 과속저속관리와, 교통류가 임계상태에 가까워 졌을 때 혼잡교통류로의 전이를 예방 혹은 최대한 늦추는 것을 목표로 하는 밀도관리로 구성된다. 현재 교통 상용 시뮬레이션 소프트웨어로는 개발차량의 속도를 관리하는 본 연구의 알고리즘 모사와 평가가 불가능하여, COM(Component Object Model) Interface를 통해 VISSIM과 직접 작성한 프로그램 코드를 가지고 시뮬레이션 테스트 베드를 구축하여 이러한 효과평가를 수행하였다. 평가 결과 본 연구에서 제안한 알고리즘에 의해 적정속도를 관리 할 경우, 혼잡이 줄어들고 통행시간도 감소하는 효과를 볼 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3858-3874
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• 2021

As an essential part of the urban transportation system, precise perception of the traffic flow parameters at the traffic signal intersection ensures traffic safety and fully improves the intersection's capacity. Traditional detection methods of road traffic flow parameter can be divided into the micro and the macro. The microscopic detection methods include geomagnetic induction coil technology, aerial detection technology based on the unmanned aerial vehicles (UAV) and camera video detection technology based on the fixed scene. The macroscopic detection methods include floating car data analysis technology. All the above methods have their advantages and disadvantages. Recently, indoor location methods based on wireless signals have attracted wide attention due to their applicability and low cost. This paper extends the wireless signal indoor location method to the outdoor intersection scene for traffic flow parameter estimation. In this paper, the detection scene is constructed at the intersection based on the received signal strength indication (RSSI) ranging technology extracted from the wireless signal. We extracted the RSSI data from the wireless signals sent to the road side unit (RSU) by the vehicle nodes, calibrated the RSSI ranging model, and finally obtained the traffic flow parameters of the intersection entrance road. We measured the average speed of traffic flow through multiple simulation experiments, the trajectory of traffic flow, and the spatiotemporal map at a single intersection inlet. Finally, we obtained the queue length of the inlet lane at the intersection. The simulation results of the experiment show that the RSSI ranging positioning method based on wireless signals can accurately estimate the traffic flow parameters at the intersection, which also provides a foundation for accurately estimating the traffic flow state in the future era of the Internet of Vehicles.