• Journal of Power Electronics
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• 제19권6호
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• pp.1486-1495
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• 2019

Dealing with the DC link fault poses a technical problem for an HVDC based on a modular multilevel converter. The fault suppressing mechanisms of several sub-module topologies with DC fault current blocking capacity are examined in this paper. An improved half-bridge sub-module topology with double direction control switch is also designed to address the additional power consumption problem, and a sub-module topology called hybrid double direction blocking sub module (HDDBSM) is proposed. The DC fault suppression characteristics and sub-module capacitor voltage balance problem is also analyzed, and a self-startup method is designed according to the number of capacitors. The simulation model in PSCAD/EMTDC is built to verify the self-startup process and the DC link fault suppression features.

• Journal of the Optical Society of Korea
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• 제17권6호
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• pp.518-524
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• 2013

This study presents a new design method for a zoom lens, in which real lens groups are designed successively to combine to form a lens modules zoom system. The lens modules and aberrations are applied to the initial design for a four-group inner-focus zoom system. An initial design with a focal length range of 4.2 to 39.9 mm is derived by assigning the first-order quantities and third-order aberrations to each module along with the constraints required for optimum solutions. After obtaining the lens module zoom system, the real lens groups are successively, not separately, designed to get a zoom lens system. Compared to the separately designed real lens groups, this approach can give a better starting zoom lens and save time. The successively designed groups result in a zoom system that satisfies the basic properties of the zoom system consisting of the original lens modules. In order to have a slim system, we directly inserted the right-angle prism in front of the first group. This configuration resulted in a compact zoom system with a depth of 12 mm. The finally designed zoom lens has an f-number of 3.5 to 4.5 and is expected to fulfill the requirements for a mobile zoom camera having high zoom ratio of 10x.

• 한국정밀공학회지
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• 제18권7호
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• pp.72-84
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• 2001

This paper proposes a design methodology for customer, assembly and disassembly considering recycling. The disign process starts with the identification of customer needs, which are in turn converted into functional requirements. The concepts of Design for Customer(DFC), Design for Assembly(DFA), Design for Variety(DFV) and Design for Disassembly(DFD) are considered in the product design phases in order to decreas production variety and mass customization. And, a new module generation approach is developed for rearranging and clustering parts and subassemblies for disassembly and recycling. Based on the result of the module generation, a new configuration methodology is suggested to minimize the disassembly time or number of disassembly operations for recycling.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1205-1211
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• 2003

Having information is most important at the present age. Internet is main source of obtaining information and mobile telecommunication let people communicate each other without any time and space limitation. Recently, advanced technology in telecommunication makes two-way service possible. So, the mobile internet service combined internet with mobile telecommunication is widely and rapidly promoted. Therefore user can transmit and receive a lot of information without time and space restriction using various application technologies. This paper deals with machinery that makes human do office work conveniently in vehicle using mobile internet service. Namely, it tries to design mobile internet machinery combining of wireless payment, GPS module, mobile internet, and mobile office etc. And that can transmit and receive e-mail or documents etc. This machinery has various objects, and design process has complexity. To reduce trial error and processing complexity, Axiomatic Design Method is used to design the machinery.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.314-319
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• 2006

Main focus on balance shaft module is to reduce the vibration triggered from engine block and compensate it from unbalance mass in balance shaft. Since the performance of balance shaft module is controlled by rotor shape including unbalance mass, a design strategy on rotor is key issue on determine the quality of balance shaft system. Even the design result on balance shaft mostly affect the lay-out of housing and other related components, its issue on balance shaft should be considered in advance throughout the total design procedure. In this paper, optimal design strategy focused on balance shaft is presented to make a design process efficiently with ensuring its high performance. And its method is verified with field design process of balance shaft in commonly adapted vehicle with 3-cylinder and 4-cylinder engine.

• 전산구조공학
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• 제8권3호
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• pp.123-133
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• 1995

본 연구는 통합 구조설계 시스템의 구축에서 객체지향적인 방법론을 도입하여 건축 구조물을 객체모델링하고, 구조해석 객체모델(Structural Analysis Object Model, SAOM)과 구조설계 객체모델(Structural Design Object Model, SDOM)을 개발하여 통합 구조설계 시스템의 원형(Prototype)을 제시한다. 구조해석 객체모델은 구조부재를 모델링한 것으로 유한요소법을 이용하역 구조물의 해석을 실시하며, 구조설계 객체모델은 한국 강구조 기준에 의해 구조부재의 적합성을 검토하도록 모델링 하였다. 이 두 모델은 통합 구조설계 시스템을 구축하는데 유용하도록 의미 추상적이고, 캡슐화되고, 재사용성이 높다.

• 한국콘텐츠학회논문지
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• 제3권3호
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• pp.40-46
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• 2003

본 논문은 안전하지 못한 DCPS(Digital Contents Protection Systems)와 HOST 사이의 통신채널을 통해 서로 일치하는 암호 키를 생성하기 위한 공개키 적용을 위해 1차적으로 이산대수와 난수를 이용한 Diffie-Hellman 알고리즘을 적용하고, 2차적으로 키 관리 표준인 ANSI X9.17, ISO 8732와 PEM(Privacy-Enhanced Mail) 등에서 채택하고 있는 2개의 서로 다른 암호키를 통해 Triple DES를 적용하여 전송 선로상의 디지털콘텐츠의 안전한 전송을 수행한다. 이에 따라 설계한 정보보호 모듈은 Key Exchange 모듈, Key Derivation 모듈, Copy Protection Processing 모듈로 구성되었으며 사용자 인증 기능과 디지털콘텐츠 암호화 기능을 통해 인가되지 않은 사용자에 의한 디지털콘텐츠의 불법 복제 및 배포를 방지하교 전송선로상의 디지털콘텐츠를 보호할 수 있도록 하였다.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.166-173
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• 2013

An aluminum suspension corner module is widely used in high class passenger cars to reduce vehicle weight and improve fuel economy. According to the change of material and suspension type, the evaluation of the static strength and failure mode of the corner module is important. In this study, static strength and failure mode analysis of aluminium multi-link suspension corner module is presented. Static strength test system is designed and static failure mode tests of the corner module are carried out in longitudinal, lateral, and vertical direction. From the resuls of the tests we found that the failure modes are different compare to those of the steel corner module. The static failure modes and load-displacement curves of this study will be used as a guidance in design of a passenger car aluminium multi-link suspension corner module.

• 한국정보전자통신기술학회논문지
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• 제6권4호
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• pp.195-200
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• 2013

본 논문에서는 기업 이미지에 타격을 줄 수 있는 부정적인 SNS와 Web 데이터를 빠르게 분석하여 기업 마케팅 전략에 활용할 수 있는 SNS 및 Web 데이터 분석 시스템을 제안한다. 본 논문에서 제안하는 시스템은 SNS 및 Web Data를 수집하는 데이터 수집 모듈(Data Collection Module), 수집된 데이터를 저장하는 HBase 모듈(Hbase Module), 수집된 데이터의 의미 분석을 수행한 후 데이터의 의미를 평가 및 분류하는 데이터 분석 모듈(Data Analysis Module) 그리고 관리자에 의해 요청된 질의어에 따라 기업과 관련된 SNS와 Web데이터를 이용하여 최적화된 Map Reduce 과정을 수행하는 PSH 모듈(Priority Scheduling Hadoop Module)로 구성된다. 본 논문은 이런 모듈들을 통하여 SNS와 Web 데이터를 보다 효율적으로 관리하여 이 분석 결과를 기업 마케팅 전략에 활용할 수 있다.

• 제어로봇시스템학회논문지
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• 제15권7호
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• pp.753-759
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• 2009

As many systems depend on electronics in an intelligent vehicle, concern for fault tolerance is growing rapidly. For example, a car with its braking controlled by electronics and no mechanical linkage from brake pedal to calipers of front tires(brake-by-wire system) should be fault tolerant because a failure can come without any warning and its effect is devastating. In general, fault tolerance is usually designed by placing redundant components that duplicate the functions of the original module. In this way a fault can be isolated, and safe operation is guaranteed by replacing the faulty module with its redundant and normal module within a predefined interval. In order to make in-vehicle network fault tolerant, this paper presents the concept and design methodology of an IEEE 1451 based dual CAN module. In addition, feasibility of the dual CAN network was evaluated by implementing the dual CAN module.