• 경영과학
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• 제28권3호
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• pp.1-13
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• 2011

Hub-and-spoke transportation network is a powerful and useful network structure that takes full advantage of economies of scale on routes between hubs. In recent studies, the network structure is extended to hybrid hub-andspoke that allows direct transportation between spokes. In this study, we considered more extended network structure which is called hybrid multiple hub-and-spoke that has multiple hubs and allows direct transportation between spokes. We developed a mathematical optimization model for automotive service parts transportation planning under hybrid multiple hub-and-spoke network structure. The model suggests a long-term transportation route planning and a short-term vehicle assignment planning. The model is verified by simulation and validated in real world application to Hyundai Mobis automotive service parts transportation planning. From the simulation result, the model reduced the transportation cost about 24.7%, the total distance about 6.8% and the CO2 emissions about 8.8%. In real world application for 6 months from July to December 2010, the model reduced the transportation cost about 9.1% by changing the long-term transportation route without daily vehicle assignment planning.

• 전기학회논문지
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• 제67권3호
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• pp.343-351
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• 2018

Renewable energy sources has drawn considerable attention as clean energy sources because of changing public attitudes regarding greenhouse gas and fine dust. Recently, in this respect, the government provides the drivers of electric vehicles with various benefits such as tax reduction, financial incentives and free parking from the public to the private sector. Plug-in electric vehicles are the most common in the private sector. Otherwise, different types of battery-based buses in the public sector are being developed, and there are three main types of charging: plug-in, battery swapping and wireless. Therefore, economic assessment of charging types in each bus route is required in order to facilitate the use of battery-based buses instead of the existing CNG buses. In this paper, net present value(NPV) and B/C ratio of charging types are evaluated in consideration of the bus schedule, the cost of charging station, and the life cycle of battery, etc. per each bus route. In case study, main bus routes in Daegu City are simulated with the proposed evaluation method to validate the eco-bus project.

• 대한전자공학회논문지TC
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• 제43권8호
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• pp.77-83
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• 2006

본 논문에서는 무선 센서 네트워크에서 Directed Diffusion을 이용하여 데이터를 신뢰성 있게 전달하는 기법을 제안하였다. 각각의 노드는 자신의 이웃에 대한 정보만을 유지하고 있으나 Interest의 전파 과정을 이용하여 종단간의 전달 신뢰성을 계산함으로써 도달가능성이 높은 경로를 선택하여 전송하는 메커니즘이다. 링크의 에러율과 노드의 개수 변화에 따른 실험을 통하여 제안 방식이 데이터 전달 신뢰성을 향상시킨다는 사실을 확인하였다. 또한, 부가적인 효과로서 트래픽 부하가 분산되고 에너지 소비가 감소되어 네트워크 수명이 연장됨을 알 수 있었다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1170-1177
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• 2006

We apply VRP(Vehicle Routing Problem) to sludge collection system in this study. Sewage stores of villages are located in each village around a multipurpose dam. Sludge which is produced in sewage store of village is transported from the sewage store of village to the sewage treatment plants by the special purpose vehicle such as the tank lorry. In this paper, we propose sludge collection strategies which allocate each sewage store of village to sewage treatment plants and decide the schedule of sludge collection in order to collect sludge efficiently. The strategies aim to decrease transportation cost with deciding proposed vehicle routing and scheduling the sludge collection. When we decide route of vehicles, we consider the collection time in sewage store of village, distance between sewage store of villages and vehicle information as average velocity of vehicle, operation time of vehicle driver. We also develop the SCMS(Sludge Collection Management System) based on windows system with real data which is used in certain circumstance. And we experiment to figure out vehicle route and transportation cost throughout changing input data.

• 유통과학연구
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• 제13권5호
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• pp.23-31
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• 2015

Purpose - This study investigated competitive counteractions necessary for continuous growth in a rapidly changing logistics environment in Northeast Asia. Research Design, Data, and Methodology - Using a time series analysis, the study first investigated Northeast Asian trade scale and volume by examining online and offline material from the Ministry of Ocean and Fisheries, Busan Port Authority, and other government agencies. A literature survey was done to investigate the state and prospect of the logistics environment in Northeast Asia including changes in freight volume at major ports in the three Northeast Asian countries. Result - The results of the study suggest using the Trans-Korean Railroad (TKR), as well as promoting the North Pole and South Pole routes, to compete against changes in trade volume and the logistics environment in Northeast Asia. A SWOT analysis was done to examine the effectiveness of these strategies. Conclusions - The findings indicate that the TKR impact, using the Busan Port connecting the Trans-China Railway (TCR), the Trans-Siberian (TSR), and the North Pole Route, may be uncertain in practice considering the uncertainty in international politics.

• 산업경영시스템학회지
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• 제30권1호
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• pp.105-114
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• 2007

In this paper, we propose sludge collection strategies which allocate each sewage store of village to sewage treatment plants and decide the schedule of sludge collection in order to collect sludge efficiently. The strategies aim to decrease transportation cost with deciding proposed vehicle routing and scheduling the sludge collection. When we decide route of vehicles, we consider the collection time in sewage store of village, distance between sewage store of villages and vehicle information as average velocity of vehicle, operation time of vehicle driver. We also develop the SCMS (Sludge Collection Management System) based on windows system with real data which is used in certain circumstance. And we experiment to figure out vehicle route and transportation cost throughout changing input data.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.38-48
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• 2007

this paper analyses how much acceleration and deceleration of urban rail vehicle should be applied and how to choose an operation mode to minimize energy consumption when train runs between stations within the fixed operation time. The decided operation pattern satisfying the minimum energy consumption becomes a target trajectory and a basis for the controller design criteria. To make this goal it grasps the characteristics of urban rail vehicle, realize operation energy model of urban rail vehicle and verity the accuracy of embodied model the Matlab simulation with the same operation result of real route. It searches for operation pattern to minimize operation energy by changing the acceleration and deceleration on the imaginative route and proposes operation pattern minimizing energy consumption by applying real operation data between stations of Seoul Metropolitan Subway Line 6.

• 전기학회논문지
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• 제66권6호
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• pp.916-922
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• 2017

Security systems for inland cargo truck transportation are mostly limited to route tracking for safe and efficient transportation. With this route tracking system, the status of cargo trucks can be monitored easily within inland boundaries. In case of oil transportation by land, however, security systems ensuring transportation of a designated quantity of products have been subject to extensive research since thefts and substitution by a similar product in the transportation process have emerged as a social problem. Security devices installed in an oil tank truck must meet the explosion-proof performance standards and be applicable to varying types of trucks. Accordingly, a wireless electronic seal with RF communication functions is considered to be the most appropriate method, but e-seals on moving vehicles require such levels of performance and reliability that can overcome certain challenges including changing radio waves and topographical impediments. Considering these characteristics of oil tank trucks, this study proposes an stabilization method to enhance the RF communication performance of e-seals, based on radio simulation and experiment findings.

• 한국농촌건축학회논문집
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• 제13권4호
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• pp.25-34
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• 2011

On former days, school has realized as "where teach", but development of a technology and change of paradigm are changing school as "where study". This is meaning that student is more important and be considered than others when make school environment. Due to continuous investment of national level in several decades, in our elementary school's facilities and environment, when compare with advanced nations that we know that have come to the fairly high level. But, it is not really certainly in middle school and high school. Than the reason is, 'College entrance examination' is prior than other certain values in occasion of high school especially, and we ask a question in return whether have persuaded ourselves that school facilities and environment may change later. It is hard to find more important thing than the proposition in fact on present society. However, it is that society and facilities that can correspond to fast change of paradigm, change of curriculum, learner's change and environment have to be changed in middle school and high school now. Departmentalized Class System that applies in national middle and high school now can become an opportunity that can improve school facilities and environment of middle and high school. In such background, I studied space satisfaction and student's moving route and pattern characteristic of Departmentalized Class System high school in Chungcheongbuk-do area. And this study aims at supply the data about efficient Departmentalized Class System School's facilities plan and space use which can meet on request of students.

• 한국정보과학회논문지:정보통신
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• 제28권3호
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• pp.336-346
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• 2001

무선 ad-hoc 네트워크란 기존에 설치된 유선망이나 기지국의 도움 없이 이동 호스트들만으로 구성되는 임시적인 네트워크이며 현재 무선 ad-hoc 네트워크 환경에서 이동 호스트들간의 메시지 전송을 위해 사용될 수 있는 여러종류의 라우팅 프로토콜들이 제안되고 있다. 이러한 ad-hoc 네트워크의 응용 도메인은 매우 다양하며 그 활용의 범위 또는 네트워크의 규모에 따라 적절한 라우팅 프로토콜이 받고자 할 수 있으며 이러한 유선망 서비스를 지원받고자 할 수 있으며 이러한 유선망 서비스를 지원하기 위해서는 ad-hoc 네트어크와 유선망과의 연동이 필요하게 된다. 본 논문에서 제안하는 DSMR(Dynamic Source Multipath Routing) 프로토콜은 무선 ad-hoc 네트워크 환경에서 이동 호스트들간의 끊김 없는 통신 환경의 제공을 목적으로 하면서 필요시에 각 호스트가 주기적으로 라우팅 메시지를 방송할 필요가 없도록 하며 경로 요청 및 경로 설정이 데이터 패킷을 보내고자하는 이동 호스트 주체로 이루어지도록 한다. 또한 다중 경로를 유지하도록 함으로써 경로의 빠른 재설정을 가능하게 한다는 특징을 갖는다.