• Proceedings of the KIEE Conference
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• summer
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• pp.1388-1390
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• 2004

경부고속철도 급전구간을 운행하는 KTX 고속열차는 싸이리스터 위상제어방식을 사용하는 대용량의 집중부하로 고속열차가 운행될 때 차량에서 발생되는 많은 고조파 전류가 철도급전계통으로 유입된다. 이러한 고조파 전류가 한국전력계통으로 유입되면 한전계통의 전압왜형율을 증가시켜 전력품질을 저하시키게 된다. 이에따라 모든 고속철도 변전소에는 고조파 전류 저감을 위한 필터설비가 설치되어 있다. 필터설비 설치에 따라 고속철도 급전계통으로 유입되는 고조파 전류와 전압왜형율 측정결과로 고조파 저감효과를 보인다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.661-664
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• 2006

과거 텔레매틱스와 DMB 기술 융합 모델은 대표적인 통방 융합의 예견되어 왔으며, DMB는 교통정보, 지도, POI 등 대용량의 텔레매틱스 컨텐츠를 방송망을 통해 내려 보낼 것으로 예측되었다. 하지만 현재 DMB 방송에서 비디오/오디오 보다 데이터 수익성이 적어 많은 대역폭 할당에 할 수 없는 실정이다. 본 논문은 방송에 적합한 텔레매틱스 컨텐츠를 컨텐츠별로 우선순위를 정함으로써 제한된 대역폭에서도 전송 주기를 효과적으로 조절하여 차량의 고속 이동 중 음영지역을 고려하여 단방향 통신의 수신율을 향상시켜줄 수 있다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.11
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• pp.930-937
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• 2012

Newly developed Series hybrid low-floor articulated vehicle which can meet both road and railway running conditions. It has the rated driving speed of 80 km/h and three driving modes with hybrid(engine+battery) driving mode, engine driving mode, battery driving mode. The battery driving mode requires the several 10 km running without additional charging operation. The vehicle has been equipped with LPB (lithium polymer battery) pack for the series hybrid propulsion system. LPB pack consists of 168 cells (3.7 V in a cell, 80 Ah) in series, DC Circuit breaker, mechanical rack, BMS (battery management system). This paper has shown the design process of LPB pack and application to the vehicle. Driving results in the road was successful to be satisfied with the requirement of the series hybrid vehicle.

• Journal of Korea Spatial Information System Society
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• v.7 no.1 s.13
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• pp.13-24
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• 2005

Objects, which change their positions over time such as cars, are called moving objects. Trajectories of a moving object have large volumes because trajectories are accumulated. Efficient indexing techniques for searching these large volumes of trajectories are needed in the moving object databases. Especially the TB-tree which supports bundling trajectories is suitable for processing combined queries which have 2 steps: first step is selecting trajectories (range search), next is selecting the parts of each trajectory (trajectory search). But the TB-tree has unnecessary disk accesses cause of lack of spatial discrimination in range queries. In this paper, we propose and implement the splitting polity which can reduce dead spaces of non-leaf node in order to process range queries efficiently. The policy has better performance about range queries than the TB-tree as well as the advantages of the TB-tree, such as highly space utilization and efficient trajectory extraction. This paper shows that the newly proposed split policy has better performance in processing the range queries than that of the TB-tree by experimental evaluation.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.88-97
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• 2010

Recently the more convenient services are provided to people in the city in line with the change of city paradigm and the recent development of ubiquitous. For example, Information on bus arrivals an effective advertisement the combination of high technology and departures through smart-phones. However, in respect of the mobile advertisement, because of difficulties such as the means of transferring the mass storage data or the burden of communication charges. there need means to improve such difficulties. This study has been conducted aiming to overcome such difficulties. This study suggests the strategic differentiation plan through the analysis of the media characteristics such as real time service information when in traveling, U-Bus business model in the category of mobile advertisement, etc. and also the concrete system establishment plan from the operation center via network to the delivery of the advertisement through vehicle terminals. In respect that this study suggests the implications as a practical business model through the fusion of high technology and diverse media. It has great significance.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.413-420
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• 2020

The Tactical Information and Communication Network system provides real-time multimedia services such as voice and data by utilizing the Mobile Subscriber Access Point. At this time, an external transmission path is constructed through the Low Capacity Trunk Radio and the High Capacity Trunk Radio system. The communication devices of each wireless transmission system are mounted on a tactical vehicle and a secondary battery is used to prevent a power interruption when the supply power to the tactical vehicle is transferred to the integrated power control device. In this paper, the basic design of the Wireless Power Transfer device for charging the battery of the integrated power control system of the mobile base station system using the Loading Distribution Method and checking the number of primary windings and the core material selection by the air gap through the Finite Elements Method.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1605-1606
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• 2015

전기철도차량은 매 순간마다 이동하는 대용량 단상부하로, 전력계통 측면에서 부하의 특성이나, 계통구성의 형태 및 제반현상이 일반 3상 전력계통과 상이한 특성을 지닌다. 이와 같이 3상 전력계통으로 부터 단상 교류로 변환하여 전기차를 운행하는 경우에는 3상 전원측 PCC(Point of Common Coupling)에 불평형을 일으켜, 역상전류를 발생시킨다. 현재는 이를 최소화하기 위해서 종래부터 사용 되어온 스코트 결선 변압기를 사용하고 있다. 하지만 특성상 두 개의 단상 시스템에 걸리는 부하량 및 역율이 동일하지 않을 경우 여전히 3상 전압불평형이 발생된다. 이에 대한 근본적인 대책으로는 급전시스템 재구성 또는 전력 설비 증설 및 보상장치의 적용을 들 수 있으나, 최근에는 전력전자 기술의 발달로 IGBT(Insulated Gate Bipolar Transistor) 소자를 이용한 BTB(Back To Back) 방식의 컨버터를 활용한 사례가 연구되고 있다. 본 논문에서는 전력계통과 전기철도의 연계 목적으로 3상-단상 BTB 모듈형 멀티레벨 컨버터 (Modular Multi-level Conveter, MMC)를 이용한 전기철도 급전 시스템의 기본구조를 제안하고, Mathworks사의 MATLAB Simulink tool를 이용하여 시뮬레이션을 통해 MMC시스템을 검토하고자 한다.

• Journal of Navigation and Port Research
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• v.37 no.5
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• pp.535-541
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• 2013

Expressways are built to provide for high levels of safety and efficiency in the movement of large traffic volumes at high speeds. However, Gyeongbu and Namhae expressways in the country which are often suffering from the transportation problems with increased import and exoprt cargo trucks including the container vehicles are the major expressways having the Busan Port as the origin and destination regions, and are required to study the expressway traffic characteristics for reducing the transportation problems. We therefore attempted to suggest the expressway density predictive model through the correlation analysis between lane occupancy and mean density at the 8-lane basic segments of the above major expressways in the country.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.233-241
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• 2018

Recently, integrated railway safety monitoring and control system, which is a convergence system based on data distribution service for railway safety monitoring and control, is under development. It collects safety data of vehicle, signal, power and safety monitoring facilities in real time and adopts communication middleware based on distributed service for mass data processing. However, in the case of a server device used as an existing control server, the performance of the distributed service middleware can not be exhibited due to low hardware performance due to safety reasons. In the safety control system, 200,000 packets per second were set as the transmission target, but the performance test of the LAB was not satisfied. In this paper, we analyze the characteristics of railway data to improve the data collection performance of existing equipment and apply DDS-based streaming transmission method to the data model of signal facilities and vehicle facilities with large packet amount according to the analysis result. As a result, it was confirmed that the throughput was improved about 30.4 times when the hardware performance was the same. We plan to improve the data processing performance by applying it to real-time railway safety integrated monitoring and control system in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.337-339
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• 2015

As much interest recently location based service, a study to analyze the movement patterns of the users from getting a lot of large amounts of data collected from a GPS installed in the smart device. Also it is recorded in the log file in the form of day-to-day personal computer, the development of a variety of a smart phone, a black box, and navigation. This data is collected by the user have been developed a variety of personalized services. In this paper, using the black box camera, such as the vehicle to form a social network platform that broadcasts real-time traffic utilization real-time video information.