• 제목/요약/키워드: reliability requirements

검색결과 812건 처리시간 0.034초

흡입공기량 간접계측방식의 전자제어화 Motorcycle 엔진 출력 특성 (Output Characteristics Using Indirect Measurement of Air Flow in a Motorcycle Engine)

  • 정태균;채재우
    • 한국자동차공학회논문집
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    • 제13권3호
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    • pp.87-95
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    • 2005
  • Most of the motorcycle engines have used carburetors in the fuel system, because of its simple structure and reliability but the fuel economy and the emissions of those engines are bad when we compared with automobile engines .To meet with the tighten emission regulations and the higher requirements for fuel economy, the application of the carburetor on the motorcycle engines would be limited. Therefore, it is important to develope a ECU control system for motorcycle engines. Since the fuel injection system is expensive, it is necessary to decrease the cost of ECU system for motorcycle engines, but the accuracy of the ECU control system should be increased as high as possible. In this paper, we studied about the AFS characteristics of motorcycle engine controled by indirect method.

Web-based Information Systems and Service Quality of IS Department

  • Lee Woongkyu
    • 한국정보시스템학회:학술대회논문집
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    • 한국정보시스템학회 2003년도 춘계학술대회
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    • pp.169-181
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    • 2003
  • As growth of the web-based applications, the requirements of the users who have been very familiar to the web-based user interfaces and customer-oriented services on the Internet would become more knowledge-intensive and higher technology involved in a more convenient and polite way of service delivery. Therefore, the service quality of information system department should be considered as a very important factor influencing success of information systems. The objective of this study is to provide the relationship between service quality of IS department and its impacts such as use, user satisfaction and job performance. For this purpose, we provide a research model for it and test it empirically for the users of the corporate portal in one of main telecommunication service providers in Korea. In result, our model with satisfiable validity and reliability shows not only importance of IS departments' service quality but also two-faced characteristics of service quality. That is, while technical competence which means with knowledge and expertise of IS department staffs is more related with user satisfaction on information systems, personal service which means the way and manner of service delivery is more related with use of it.

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ERTMS/ETCS의 TSI 절차에 관한 분석 (The analysis of TSI procedure in the ERTMS/ETCS)

  • 이상혁;김민석;정대영;고영환;이종우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.125-131
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    • 2011
  • TSI(Technical Specification for Interoperability) is the highest technical specification in the Europe Railway and is composed by assessment items and essential requirements included by safety, reliability, availability, health, environment protection and technical compatibility. It is used on the research and development in the next generation railway technical. Currently, TSI procedures have been asked to bid for high speed rail business in Europe and Brazil. Also, all the railway systems such as infrastructure, signaling, electric and rolling stock system corresponding with standard of TSI procedures are exported and imported. Recently, Safety Critical System which has been studied on future railway R&D business in Korea is the state of the art train control system. And it is needed for system assessment of TSI procedures before system test and operation. In this paper, basic research is performed for analyzing TSI procedures suitable for the state of the art train control system in Korean railway.

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4G LTE 기술을 적용한 고속철도 통신/신호 시스템 영향력에 관한 연구 (Study on the Effectiveness of High-Speed Railway Communication and Signaling System Based on 4G LTE Technology)

  • 손연;이창영;한영재;이진
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.2795-2803
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    • 2011
  • Due to speed acceleration, higher requirements have been put forward to high speed railway communication and signaling system. The railway applications, including intra-train, train to ground and trackside networks, demand larger bandwidth, higher reliability and shorter response time from railway communication networks to ensure security operation and passenger communication. However, the current railway communication and signaling system has lagged behind the railway development, so advanced communication technologies are needed to improve the current situation. This paper presents high speed railway communication and signaling system based on 4G LTE technology, introduces its network architecture, key technology and analyzes its technical advantages compared with GSM-R system. According to analysis, LTE based high-speed railway communication network is more effective and reliable.

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The Role of Electronic Trade Specialized Service Provider under Global Trade Environment

  • Lee, Bong Soo
    • 무역상무연구
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    • 제60권
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    • pp.235-255
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    • 2013
  • This thesis examines the problems faced in the electronic trade specialized service provider for which improvements are necessary, and suggests various ways of overcoming those problems. First, from the legal aspect, it is necessary to clarify the scope of duties as well as to expand the threshold for entrance and business areas through the amendment of related laws. Second, from the operating aspect, the e-trade specialized service provider should be able to provide convenient work spaces through user-centered interface by connecting, integrating, automating and simplifying various services scattered around through the establishment of an operating system. Third, from the institutional aspect, trade firms should be able to perform e-trade duties without difficulties by specializing and increasing the size of the e-trade specialized service provider system and strengthening job competence. For this, it is required to improve legal registration requirements to enhance the reliability of the e-trade specialized service provider system and secure its financial capacity.

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대형 LCD-TV용 LED-BLU 방열 설계에 관한 연구

  • 정기호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.15-15
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    • 2009
  • In many applications for display with LED, the thermal behavior of LED is most important issue in view of thermal management. The optical requirements of the displays for various applications make the designer to drive the LED at or over their on-design condition to achieve performances requested by users. In practical cases of large-sized TV with LED back light unit (BLU), the problem of increasing LED temperature can affect the reliability of LED itself and the optical performances of BLU as an assembly of LED. In this paper, the thermal management design of LED back light unit(BLU) for large-sized TV was performed

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공작기계 베어링 결합부의 동적 모델링 연구 (A Study on the Dynamic Modelling of Bearing Joints in Machine Tools)

  • 이신영;이장무
    • 한국정밀공학회지
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    • 제9권2호
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    • pp.61-68
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    • 1992
  • To meet the requirements for accuracy, productivity and reliability of machine tools, it is necessary to evaluate the chatter-free machining performance and to improve the dynamic performance of machine tools. In order to perform dynamic design of machine tools reasonably and effectively, the joint parts must be modelled accurately because their characteristics affect significantly on the total characteristics of machine tool. In this paper, an approach which identifies the effect of joint parts on the performance of total machine tool structure was proposed. That uses the experimental modal analysis, the finite element method and the sensitivity analysis method. The effectiveness of this approach was confirmed by applying it to structures with bearing joints. And as a result of the application, the change of dynamic characteristics of bearing joints was indentified.

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자기적으로 결합된 PCB권선을 이용한 무접점 배터리 충전기 (A New Contactless Battery Charger Using Coupled Printed Circuit Board Windings)

  • 노재현;차헌녕;최병조;안태영
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제51권1호
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    • pp.16-22
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    • 2002
  • The Proposed contactless charger employs a Pair of neighboring Printed circuit board (PCB) windings as a contactless energy transfer device, thereby making it amenable to low-Profile designs and suitable for applications to the portable telecommunication/computing electroncis in which stringent requirements for height, space, and reliability have to be met. The performance of the proposed charger is confirmed with experiments on a prototype charger developed for cellular phones

분산발전용 75kW급 마이크로터빈의 시제개발 - 설계/제작 및 자력운전 시험 - (Prototype Development of A 75kW Class Microturbine - Design/Manufacture and Self-Sustaining Test -)

  • 오종식;이헌석
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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    • pp.307-313
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    • 2002
  • In the paper, the prototype development of a 75kW class microturbine for the distributed generation market is partly presented which has continued with the government funding. In the introduction, an overview of the development of microturbines in the world is presented. A series of development procedures are shown with design, manufacture and self-sustaining tests. During the first year, aerodynamic and structural design/analysis, mechanical design are performed for the compressor, the turbine and the combustor. A premixed lean burn combustor technology is used fur the low emission requirements. Foil air bearings and high-speed motors are employed for higher reliability. The self-sustaining conditions have been successfully achieved with the prototype manufactured engine as a preceding operation.

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복잡한 내장형 소프트웨어를 위한 테스트 모델 설계 (Design of Testing Model for Complex Embedded Software)

  • 이명호;이상용;장중순;최경희;박승규;정기현
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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    • pp.611-614
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    • 2004
  • As information telecommunication industry develops and systems get integrated gradually, the importance of embedded software is growing significantly. On the contrary, the reliability of embedded software has worsened. Accordingly, testing of software is an essential part in designing and building up embedded system and the volume of testing required is immense. This paper elaborates on design and testing model for complex embedded software, providing guidelines to collect requirements for complex embedded software.

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