• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권1호
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• pp.40-47
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• 2002

This paper describes a re-adhesion control method for the Korean High-Speed Train (KHST) with parallel induction motor drive. To keep a traction efficiency and to improve vehicle maintenance, the adhesion characteristics between wheel and rail are analyzed. Also the re-adhesion controller is designed as the subsystem of induction motor vector control. In order to verify performance of the proposed control techniques, the simulation is executed by train model and a downscaled re-adhesion control simulator is utilized. Both simulation and running test results show that good re-adhesion characteristics are obtained.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권4호
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• pp.221-227
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• 2007

This paper introduces an on-line particle-filtering-based framework for failure prognosis in nonlinear, non-Gaussian systems. This framework uses a nonlinear state-space model of the plant(with unknown time-varying parameters) and a particle filtering(PF) algorithm to estimate the probability density function(pdf) of the state in real-time. The state pdf estimate is then used to predict the evolution in time of the fault indicator, obtaining as a result the pdf of the remaining useful life(RUL) for the faulty subsystem. This approach provides information about the precision and accuracy of long-term predictions, RUL expectations, and 95% confidence intervals for the condition under study. Data from a seeded fault test for a UH-60 planetary carrier plate are used to validate the proposed methodology.

• 한국철도학회논문집
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• 제9권5호
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• pp.606-611
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• 2006

This paper presents a procedure and an analysis method to evaluate reliability of the Korea high-speed train. The rolling stock system is divided into 6 sub-systems and each subsystem is classified into sub-assemblies. Functional analysis has been conducted to draw reliability block diagrams for the sub-systems. First, failure rates has been calculated for each sub-assembly from the failure data obtained during commissioning tests. Then a reliability block diagram is used to evaluate the MKBF(Mean Kilometers Before Failure) of the sub-systems. Activities to increase reliability have been carried out throughout the test runs and analysis results show that the reliability of the rolling stock system is gradually growing in time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2136-2152
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• 2012

The growth of Internet technologies and the widespread use of mobile devices have been paving the way for the increasing use of conferencing services. Two types of systems have been designed to provide conferencing services: 1) a conferencing system using session control over a peer-to-peer (P2P) network and 2) an IP Multimedia Subsystem (IMS) conferencing system. The IMS conferencing system was developed to adapt to a server-based centralized system, whereas the benefits of the P2P operational model in providing such conference services are widely acknowledged. However, each system provides conferencing services only to its own users. Therefore, in this paper, we propose an interworking model to support multimedia conferencing service between the P2P environment and IMS networks. We also introduce protocol architecture and some service scenarios. To verify this system model and the design architecture, we perform an actual implementation and show experienced test results.

• 대한인간공학회지
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• 제16권1호
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• pp.97-105
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• 1997

An aircraft simulator for ergonomics testing and pilot training was developed from the joint work Agency for Defense Development(ADD) and Daewoo Heavy Industry, LTD, in Korea at first time. It is basically to satisfy the requirements established by FAA-AC-120-40C ( 1995-JAN-26). The aircraft simulator will be used mainly for ergonomics testing and pilot training for basic trainer on ADD and Korea Air Force in near futrue. This simulator reproduces faithfully the cockpit and flight characteristics of the KTX-1 aircraft. It is one of the latest full flight simulators that have the CGI(computer graphic image) visual system and six degree of freedom motions system. Development efforts focused on user-oriented design approach for ergonomics testing and flight training of pilots. Main characteristics of each subsystem are described such as cockpit, instruments, control loading system, motion system, visual system, aural system, instructor operation station and aircraft simulation softwear.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.135-143
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• 2003

In this study, a real-time simulation model was developed for tracked vehicles with in-arm type semi-active hydro-pneumatic suspension unit using MATLAB S-functions. Since the vehicle model uses relative coordinates and massless link elements, the developed model has an enhanced analytic time performance. Through the comparison of simulation results with multi-body software(DADS), the vehicle model is verified. A controller using on-off skyhook control algorithm is designed with the pilot-centre]led proportional valve based on conventional damper characteristics. Exploiting the developed tracked vehicle model with other subsystem model such as a controller model, a suspension unit model, and a test road model, computer simulations are carried out. Control simulation results with the developed tracked vehicle model show that the semi-active suspension control system has a better performance than the conventional suspension system.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 공동추계학술대회
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• pp.359-368
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• 2005

Personalized reminder systems have to identify the user's current needs dynamically and proactively based on the user's current context. However, need identification methodologies and their feasible architectures for personalized reminder systems have been so far rare. Hence, this paper aims to propose a proactive need awaring mechanism by applying agent, semantic web technologies and RFID-based context subsystem for a personalized reminder system, which is one of the supporting systems for a robust ubiquitous service support environment. Rescorla-Wagner model is adopted as an underlying need awaring theory. We have created a prototype system. called NAMA(Need Aware Muiti-Agent)-RFID. to demonstrate the feasibility of the methodology and of the mobile settings framework that we propose in this paper Moreover, to test if the proposed system works in terms of scalability, a simulation was performed and the results are described.

• 한국항공우주학회지
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• 제34권4호
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• pp.102-109
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• 2006

본 논문에서는 검증위성(KoDSat)의 시스템 레벨 전자기파(EMC) 환경시험 및 전자기파(EMC) 규격을 초과한 시험결과에 대해서 발사체에 대한 영향성 분석 및 하드웨어 개선 방법에 대하여 논하고, EMC2000 소프트웨어 해석을 통해 KSLV-1 발사체의 비행종단시스템(FTS : Flight Termination System)에 영향을 줄 수 있는 검증위성의 전자기파 노이즈원을 도출하였다. 또한 도출된 전자기파(EMC) 노이즈원은 EMI 필터, 접지, 쉴딩(Shielding) 처리 기법을 데이터획득장치(DAU) 전력보드(Power Board)에 적용하여 미약한 값으로 제거되었다. 그리고 이와 같은 일련의 분석과정에 의해 새로 설계된 전력보드는 검증차원에서 데이터획득장치(DAU)에 장착되어 박스자체 전자기파(EMC) 시험 및 최종 2차 검증위성 시스템 레벨 전자기파 시험을 통해 확인되었고, 측정 결과는 저주파대역과 UHF 주파수대역(430Mhz)에서 만족할 만한 감쇄레벨 값을 나타내었다.

• 한국추진공학회지
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• 제18권1호
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• pp.91-96
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• 2014

KSLV-I (Korea Space Launch Vehicle-I) 상단 킥모터는 고체 추진기관으로 점화기와 점화안전장치로 구성된 점화구동부, 복합재 케이스부, 추력벡터제어가 가능한 잠입형 노즐부, 그리고 추진제로 구성되어 있다. 킥모터를 구성하는 각 서브시스템들은 비행 임무 달성을 위한 개발 요구조건을 만족시켰으며, 2013년 1월 30일 나로호 3차 비행 시험 결과로부터 성공적으로 개발이 완료되었음을 확인할 수 있었다. 본 논문에서는 킥모터에 대한 요구조건, 요구조건을 만족하기 위한 형상관리, 중량 변화, 추력 축 정렬 결과 및 주요 시험 결과 등에 대해 다루었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.436-439
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• 2004

Output data streams of the MSC contain flags, Headers and image data according to the established protocols and data formats. Especially the Header added to each data lines contain information of a line sync, a line counter and, ancillary data which consist of ancillary identification bit and one ancillary data byte. This information is used by ground station to calculate the geographic coordinates of the image and get the on-board time and several EOS(Electro-Optical Subsystem) parameters used at the time of imaging. Therefore, the EGSE(Electrical Ground Supporting Equipment) that is used for testing MSC has to have functions of interpreting and displaying this Header information correctly following the protocols. This paper describes the design of the header data processing module which is in EOS­EGSE. This module provides users with various test functions such as header validation, ancillary block validation, line-counter and In-line counter validation checks which allow convenient and fast test on imagery data.