• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.329-334
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• 2021

Korean Air has set the goal of the first stage of the development of unmanned helicopters to perform in hovering flight by remote control. In order to achieve the development goal, Korean Air carried out system integration, ground test, and safety wire test in sequence after carrying out programmed depot maintenance and aircraft modification of manned aircraft, and verified the controllability and flight safety of the unmanned helicopter system step by step. In particular, it was confirmed that the safety wire test technique used in the final stage of verification was an effective method to verify flight safety and controllability for a fully unmanned helicopter system.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2359-2373
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• 2008

In 1991, Korean government decided to establish the Inland Container Depot for activating transportation of rail freight container and encourage the effectiveness of intermodal transport system. Therefore, the Ui-Wang ICD has been built in Kyonggi province and began to operate in 1993. However, Despite of original purpose of the Inland Container Depot, rail freight volume at public CY(Container Yard) in Ui-Wang ICD has been recorded very low. This paper deals with the promotion strategy for rail transport in Ui-Wang ICD. The relationship of conflicts between the rail-oriented transporters and road-oriented transporters in Ui-Wang ICD have been found through the TOC thinking process and some solutions are suggested. Some undesirable effects in operation of Ui-Wang ICD are listed and current reality tree(CRT) has been established and future reality tree(FRT) which includes some injections to active the rail transport in ICD has been recommended based on CRT. In order to make good solutions the situation in Busan-jin station ICD known as similar to Ui-Wang ICD has been analyzed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.24-34
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• 2014

In order to manage essential parts that are required for the repairable parts services performed at the military maintenance depots, the United States Air Force developed the Repairability Forecasting Model (RFM). In the RFM, if the requirements of the parts are assumed to follow the normal probability distribution after applying means from the past data to the replacement rate and lead times, the chance of the AWP (Awaiting Parts) occurring is 50%. In this study, to counter the uncertainties of requirements and lead times from the RFM, the safety level concept is considered. To obtain the safety level for requirements, the binomial probability distribution is applied, while the safety level for lead time is obtained by applying the normal probability distribution. After adding this concept, the improved RFM is renamed as the ARFM (Advanced RFM), and by conducting the numerical stimulation, the effectiveness of the ARFM, minimizing the occurrence of the AWP, is shown by increasing the efficiency of the maintenance process and the operating rate of the weapon system.

• The Journal of Society for e-Business Studies
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• v.1 no.2
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• pp.117-131
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• 1996

This paper presents the results of the systems analysis for the FCIM (Flexible Computer Integrated Manufacturing) system at the U.S. Tobyhanna Army Repair Depot, which is one of the RAMP (Rapid Acquisition of Manufactured Part) program sites for CALS implementation in the U.S. military. The FCIM system's acquisition and supply processes are represented by IDEFO function models and FCIM information systems are briefly decribed in this paper. The models presented here can be used at a reference for the development of CALS acquisition and supply systems. In addition. the distinction between input and control information on the IDEFO model it suggested from the practical modeling viewpoint.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.2
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• pp.225-242
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• 2006

This study aims to analyze the spatial distribution pattern of international trade. The method is to analyze the principal components by changing interaction attribute matrix of four dimensions (hinterland, gateway, foreland and commodities) into two dimension matrix. The study area is the territory region of Cheongju clearance depot in inland. The result are as follows : Major spatial patterns of regional connections by hinterland, gateway and foreland are, in the case of exports, ten patterns and in the case of imports come to nine. Composition of major export and import commodities in Cheongju clearance depot are similar, but precision instrument manufactured commodity and nonmetal mineral are remarkable in export and mineral manufactured commodity machinery and electronic manufactured commodity are remarkable in import. Gateway are similar to export and import, but Incheon international airport is used more in the case of import. And Cheongiu international airport is used for some commodities and is remarkable as a foreland of import for the areas outside of Chungcheongbuk-do.

• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.121-132
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• 2015

Yangsan ICD (Inland Container Depot) has played an important role for Busan Port and Korea's port & logistics industries, increasing international logistics competitiveness and containers' transportation competitiveness in Busan region dealing with 1330 thousand TEU in 2005, since its opening in March 2000. However, it is necessary to seek new measures to revitalize Yangsan ICD, since its cargo volume decreased rapidly owing to the opening of Busan New Port and hinterland in 2006. This study constructed an evaluation model using AHP (Analytic Hierarchy Process) and conducted a survey targeting local businesses and persons concerned in Yangsan ICD to seek measures for revitalization. The results suggest that Yangsan ICD needs to switch functions to logistics centers (terminal facilities, logistics warehouse) for revitalization considering its advantage of facility location. Moreover, by extending the utilization period and securing building-to-land ratio, existing and new businesses' stable activity should be guaranteed. Furthermore, utilizing facilities such as the railway station in ICD, an active railway revitalization policy may increase cargo volume. Yangsan ICD should perform its role as an inland logistics depot through the revitalization of railway freight transportation in the national logistics system focusing on road freight transportation.

• Journal of Korea Port Economic Association
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• v.35 no.3
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• pp.73-92
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• 2019

Disasters and crises are spreading across the globe, and there has been an increase in the number disasters in northeast Asia, such as earthquakes in Sichuan, China, and East Japan. This study aims to propose a plan to attract facilities from the United Nations Humanitarian Response Depot (UNHRD). Although there are no prior domestic studies, the study focuses on the role of intangible benefits, values, and economic outcomes in attracting facilities. Based on an analysis of strengths, weaknesses, opportunities, and threats (SWOT) of Korea's host environment, using the UN's annual report and Korea's overseas emergency relief data, the study will analyze the status of relevant UN organizations and derive detailed strategies. In order to attract facilities from the UNHRD, it will be necessary to build and promote a cooperative system with domestic and foreign NGO experts in humanitarian assistance and joint proposals from government departments and local governments. In the long-run, it will be necessary to work closely with the relevant UN agencies to achieve strategic progress.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.5
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• pp.248-254
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• 2001

The traction power demand highly varies with time and train positions and the traction load is a large-capacity current at single phase converted from 3-phase power system. Subsequently, each phase current converted from 3-phase power system cannot be maintained in balance any longer and thus the traction load can bring about imbalance in three-phase voltage. Therefore, the exact assessment of voltage unbalance must be carried out preferentially as well as load forecast at stages of designing and planning for electric railway system. The evaluation of unbalance voltage in areas, such as electric railway depots should be a prerequisite with more accuracy. The conventional researches on voltage unbalance have dealt with connection schemes of the transformers used in ac AT-fed electric railroads system and induced formulas to briefly evaluate voltage unbalance in the system(3). These formulas are still being used widely due to their easy applicabilities on voltage unbalance evaluation. Meanwhile, they don't take into account detailed characteristics of ac AT-fed electric railroads system, being founded on some assumptions. Accordingly. accuracy still remains in question. This paper proposes a new method to more effectively estimate voltage unbalance index. In this method, numerous diverted circuits in electric railway depots are categorized in three components and each component is defined as a two-port network model. The equivalent circuit for the entire power supply system is also described into a two-port network model by making parallel and/or series connections of these components. Efficiency and accuracy in voltage unbalance calculation as well can be promoted by simplifying the circuits into two-port network models.

• Journal of the Korean Society for Railway
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• v.16 no.5
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• pp.353-357
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• 2013

Property development along railway lines is a critical issue at present. Because various railway lines exist in most large cities, there are numerous properties and open spaces to be developed for communities associated with these lines. The active development of railway properties can be a means to resolve housing shortage problems in cities. In this first part of this paper, noise and vibration levels of an artificial area of land and apartment complex are measured and evaluated to derive a design strategy for vibration reduction purposes.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.28-36
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• 2016

Recently, owing to the development of ICT industry and wide spread of smart phone, the number of people who use car sharing service are increased rapidly. Currently two-way car sharing system with same rental and return locations are mainly operated since this system can be easily implemented and maintained. Currently the demand of one-way car sharing service has increase explosively. But this system have several obstacle in operation, especially, vehicle stock imbalance issues which invoke vehicle relocation. Hence in this study, we present an optimization approach to depot location and relocation policy in one-way car sharing systems. At first, we modelled as mixed-integer programming models whose objective is to maximize the profits of a car sharing organization considering all the revenues and costs involved and several constraints of relocation policy. And to solve this problem efficiently, we proposed a new method based on particle swarm optimization, which is one of powerful meta-heuristic method. The practical usefulness of the approach is illustrated with a case study involving satellite cities in Seoul Metrolitan Area including several candidate area where this kind systems have not been installed yet and already operating area. Our proposed approach produced plausible solutions with rapid computational time and a little deviation from optimal solution obtained by CPLEX Optimizer. Also we can find that particle swarm optimization method can be used as efficient method with various constraints. Hence based on this results, we can grasp a clear insight into the impact of depot location and relocation policy schemes on the profitability of such systems.