• Title/Summary/Keyword: reliability and safety

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SE Application Methods of Pre-Business for Effective Operation of Driveless LRT System (무인운전경전철시스템의 효과적 운영을 위한 사업초기단계 SE적용방안)

  • Chung, Su-Young;Park, Soo-Choong;Min, Kyung-Se;Jeon, Seo-Tak
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.3312-3317
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    • 2011
  • Recently, the demand regarding reliability and safety of the railroad are increased as built to Driverless LRT system. Therefore, PM and SE technique is applied for efficient management of a construction business. In case of SE(System Engineering) in domestic, most foreign companies are doing to lead but we are under effort for the environment that a domestic company can lead. In this study, We emphasize to SE importance of pre-business for operation to be effective of Driveless LRT system, and propose about activities in the SE at requirements definitions and requirements analysis steps of a highest level. To achieve this, We propose SE Application Methods of Pre-Business regarding assistance process of project planning, evaluation and control, and risk management.

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A Research of Obstacle Detection and Path Planning for Lane Change of Autonomous Vehicle in Urban Environment (자율주행 자동차의 실 도로 차선 변경을 위한 장애물 검출 및 경로 계획에 관한 연구)

  • Oh, Jae-Saek;Lim, Kyung-Il;Kim, Jung-Ha
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.2
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    • pp.115-120
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    • 2015
  • Recently, in automotive technology area, intelligent safety systems have been actively accomplished for drivers, passengers, and pedestrians. Also, many researches are focused on development of autonomous vehicles. This paper propose the application of LiDAR sensors, which takes major role in perceiving environment, terrain classification, obstacle data clustering method, and local map building for autonomous driving. Finally, based on these results, planning for lane change path that vehicle tracking possible were created and the reliability of path generation were experimented.

A Study on Program Development for Preventive Maintenance of Electrical Facilities (전기수용설비 예방보전을 위한 보수지원용 프로그램 개발)

  • Kim, Se-Dong;Choi, Do-Hyuk;Ryu, Seung-Ki
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.232-234
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    • 1996
  • As a building is getting large-scale, composition and intelligence, it is required the stability of building electrical facilities. And it is very difficult of rapidly repair on a breakdown of building electrical facilities. Therefore high-reliability and efficiency of building safety is required. And thus, this study presents the repair-maintenance support program for preventive maintenance on a builing electrical facilities. This program makes offer some functions, facilities history input mode, checking and result mode. User can be made offer the cause and effect information of facilities-faults by this preventive maintenance program.

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Analysis of Common Cause Failure Using Two-Step Expectation and Maximization Algorithm (2단계 EM 알고리즘을 이용한 공통원인 고장 분석)

  • Baek Jang Hyun;Seo Jae Young;Na Man Gyun
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.2
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    • pp.63-71
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    • 2005
  • In the field of nuclear reactor safety study, common cause failures (CCFs) became significant contributors to system failure probability and core damage frequency in most Probabilistic risk assessments. However, it is hard to estimate the reliability of such a system, because of the dependency of components caused by CCFs. In order to analyze the system, we propose an analytic method that can find the parameters with lack of raw data. This study adopts the shock model in which the failure probability increases as the shock is cumulated. We use two-step Expectation and Maximization (EM) algorithm to find the unknown parameters. In order to verify the analysis result, we perform the simulation under same environment. This approach might be helpful to build the defensive strategy for the CCFs.

Exploiting Standard Deviation of CPI to Evaluate Architectural Time-Predictability

  • Zhang, Wei;Ding, Yiqiang
    • Journal of Computing Science and Engineering
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    • v.8 no.1
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    • pp.34-42
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    • 2014
  • Time-predictability of computing is critical for hard real-time and safety-critical systems. However, currently there is no metric available to quantitatively evaluate time-predictability, a feature crucial to the design of time-predictable processors. This paper first proposes the concept of architectural time-predictability, which separates the time variation due to hardware architectural/microarchitectural design from that due to software. We then propose the standard deviation of clock cycles per instruction (CPI), a new metric, to measure architectural time-predictability. Our experiments confirm that the standard deviation of CPI is an effective metric to evaluate and compare architectural time-predictability for different processors.

A Study on the Evaluation of Reliability of the Vacuum Circuit Breaker for the Electrical Fire (전기화재에 따른 진공차단기의 건전성 평가)

  • Choi, Hong-Kyoo;Park, Joon-Yeol
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.7
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    • pp.24-28
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    • 2013
  • Fire-hited electrical equipment has possibility of deterioration. So its replacement is essential in terms of safety. However, the economic burden is increased. Therefore, the replacement or re-use of it is to be determined by tests. But the research of Integrity Assessment on Fire-hited electrical equipments is very rare. In this paper, we tested to determine the replacement or re-use of Fire-hited vacuum circuit breaker. And provided the data for the integrity assessment through the analysis of its deterioration.

A Study on Temperature Characteristics for Traction Motor of High Speed Railway (고속철도차량 전동기의 열적 특성 연구)

  • Han, Young-Jae;Kim, Seog-Won;Kim, Sang-Soo;Kim, Ki-Hwan;Koo, Hun-Mo;Choi, Jung-Sun;Kim, Jung-Su
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.12
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    • pp.1123-1127
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    • 2006
  • There are various elements that have influence on safety and reliability of high speed railway. Among them, mechanical characteristics of traction motors are very important. Therefore, we verified that temperature characteristics have influence on damage and durability of these parts. We designed a measurement system for temperature test, and could measure the temperature of each device by the system. As the result of temperature test, we could confirm that the traction motors on Korean High-Speed Train satisfy the criteria. From this test, we get information of the traction motor about the temperature characteristic during running speed and running time.

Safe and Reliable Intelligent Wheelchair Robot with Human Robot Interaction

  • Hyuk, Moon-In;Hyun, Joung-Sang;Kwang, Kum-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.120.1-120
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    • 2001
  • This paper proposes a prototype of a safe and reliable wheelchair robot with Human Robot Interaction (HRI). Since the wheelchair users are usually the handicapped, the wheelchair robot must guarantee the safety and reliability for the motion while considering users intention, A single color CCD camera is mounted for input user´s command based on human-friendly gestures, and a ultra sonic sensor array is used for sensing external motion environment. We use face and hand directional gestures as the user´s command. By combining the user´s command with the sensed environment configuration, the planner of the wheelchair robot selects an optimal motion. We implement a prototype wheelchair robot, MR, HURI (Mobile Robot with Human Robot Interaction) ...

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A study on Test and Evaluation & Technology of Brake Control System in High Speed Railway (고속철도 제동제어 시험평가기술 방법에 대한 연구)

  • Shin Yu-Jeong;Choi Kyung-Jin
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.103-108
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    • 2005
  • Since the braking system of rolling stock is directly linked to it's safety, ensuring reliability of braking system and evaluation of performance of it are very important. To develope the performance of braking system, it is required advanced technology and gradually various factors in the field test result. This study is designed to analyze the air pressure control about braking force in rolling stock, also, by comparing braking force of KTX with that of high speed train. This paper suggests to establish a method of computation of braking force form the air pressure control. And The high speed train researches into patterns of braking system such as the train of speed up and introduction of electric and pneumatic braking system.

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Development and Test of Automatic/Driverless Operation System for Standardized EMU (표준전동차 자동/무인운전장치 개발 및 주행시험)

  • 안태기;이수길;한성호;이관섭
    • Journal of the Korean Society for Railway
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    • v.3 no.3
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    • pp.154-160
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    • 2000
  • The automatic/driverless operation which are great important techniques in metro railway are required to increase higher safety, greater reliability, and transport capacity. To satisfy such demands, we must have the system design and testing technique for the railway system operation. These techniques are related to the onboard train control and communication systems which include TCMS(Train Control and Monitoring System), ATO(Automatic Train Operation), ATC(Automatic Train Control), and TWC(Train to Wayside Communication). These sub-systems must be interfacing with not only each others but also the signal system on the ground. We tested the train control system on Test line that has been developed on the basis of the standardized type EMU for korea railway systems. This test line which is located in Sangju, have been constructed for testing 7 & 8 line of Seoul Metro railway.

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