• 제목/요약/키워드: top-down process

검색결과 249건 처리시간 0.035초

MAO 모델을 사용한 관계 데이타베이스의 논리적 설계방법론 (A Logical Design Methodology for Relational Databases Using the MAO (Multiple Aspects-based Object) Model)

  • 조동영;백두선;황종선
    • 한국경영과학회지
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    • 제16권2호
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    • pp.49-64
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    • 1991
  • In this paper, we present a stepwise design methodology for relational databases using a new conceptual data model, the MAO(Multiple Aspects-based Object) model. Our methodology consists two steps : first, data requirements are conceptualized using the MAO model with concepts such as objects types and aspect types : second, the MAO model is transformed into the third normal form inn the relational model supported by commercial DBMs. A top-down approach is used for the MAO modelling in the first, step, and the transformation process in the second step can be automated. Our methodology supports easier and more database design of real world than other methodologies using existing data models.

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Experimental study on natural circulation using liquid nitrogen for superconducting applications

  • Choi, Yeon Suk
    • 한국초전도ㆍ저온공학회논문지
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    • 제15권3호
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    • pp.49-52
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    • 2013
  • An experiment to investigate the natural circulation of a cryogen has been performed. The study is motivated mainly by our recent development of cryogenic cooling system for prototype superconducting cyclotron without any circulating pump. In the natural circulation loop system, a cooling channel is attached on the outer surface of the aluminium block and the liquid nitrogen passes through inside of the channel to cool the block indirectly. A cryocooler as a heat sink is located at the top to re-condense cryogenic vapor coming from the aluminium block in which electrical heater is installed as a heat source. The main dimensions are determined using the relevant analysis and the natural circulation loop is successfully fabricated. The temperature distributions in the loop are measured during initial cool-down process and in steady state, from which the modified Grashof numbers are calculated and compared with the existing correlation estimated with one-dimensional analysis for steady state flow.

수문의 자동설계 시스템 개발에 관한 연구 (A Study on the Development of Automatic Drawing System for Water-gate)

  • 김일수
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.87-92
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    • 1999
  • The biggest challenge facing today manufacturing industry is better quality and high productivity. From an economic point of view, productivity is the most important parameter, as high productivity will reduce the cost. However, the customers of today are not only cost concerned, but also quality conscious. So high accuracy levels should also be achieved in the manufacturing process. This paper reports the development of a automatic design system based on AutoCAD program. This work is composed of three section that are design of top down menu, guide frame and gate lifter for water-gate programed by AutoLISP language and runned Windows system. The developed system ultimately generates the design for a water gate through AutoCAD program. In the design of the water gate, it needs about 23 hours with an expert, but this system can be only 80 seconds without an expert.

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Soft Lithographic Approach to Fabricate Sub-50 nm Nanowire Field-effect Transistors

  • 이정은;이현주;고우리;이성규;;이민형
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.410.1-410.1
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    • 2014
  • A soft-lithographic top-down approach is combined with an epitaxial layer transfer process to fabricate high quality III-V compound semiconductor nanowires (NWs) and integrate them on Si/SiO2 substrates, using MBE-grown ultrathin InAs as a source wafer. The channel width of the InAs nanowires is controlled by using solvent-assisted nanoscale embossing (SANE), descumming, and etching processes. By optimizing these processes, the NW width is scaled to less than 50 nm, and the InAs NWFETs has ${\sim}1,600cm^2/Vs$ peak electron mobility, which indicates no mobility degradation due to the size.

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PI(Process Innovation)와 Six sigma연계 전략

  • 김영곤
    • 한국품질경영학회:학술대회논문집
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    • 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
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    • pp.160-165
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    • 2004
  • 최근 각 기업에는 6시그마, PI등 여러 가지 혁신 활동이 차별화 되지 않고 도입되는 경향이 있으며, 기업 내부에서도 바람직한 혁신활동 연계방안에 대해서 많은 고민을 하고 있는 실 정 임. 따라서 이러한 혁신활동을 잘 이해하고 통합할 수 있는 방안이 필요 할 것이며, 여기에서는 이것들을 연계한 경영 전략을 제시하고자 한다. 6시그마와 PI의 특징을 살펴보면, 비즈니스 리엔지니어링은 급격하게 변화하는 프로세스의 구성을 의미하는 것으로 볼 수 있으나 PI는 보다 포괄적인 개념이다. 즉, 새로운 작업전략(Work Strategy)의 비전설정과 실질적인 프로세스 디자인 활동을 포함한다. 또한 기술적 차원, 인간적 차원, 조직적 차원등 다차원적 변화의 추진과 실행을 의미한다. 반면에 6시그마는 고객의 요구(Customer Requirement)를 명확히 이해하고 이에 대응하는 기업의 모든 활동을 Top Down시각에서 합리적인 전사 표준을 통해 측정, 평가 후 도출되는 문제점 및 개선 사항에 대해 개선 프로세스에 따라 TFT(Task Force Team) 활동을 지속적으로 전개함으로써 총체적 고객만족을 구현하는데 궁극적인 목적을 둔다. 이러한 경영혁신 활동은 구성원의 참여를 기반으로 하며, 이에 대한 권한 위임과 더불어 지속적인 지원을 바탕으로 제품 및 서비스에 영향을 미치는 모든 부문에 걸쳐 영역 제한 없이 실시하는 것을 의미한다. 따라서 6시그마는 결코 PI를 대체할 수 없으며 상호 보완적 관계로 연계시켜 추진하는 것이 바람직하다.

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Densification and Conolidation of Powders by Equal Channel Angular Pressing

  • Yoon, Seung-Chae;Hong, Sun-Ig;Hong, Sun-Hyung;Kim, Hyoung-Seop
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.978-979
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    • 2006
  • In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve both full density and grain refinement of metallic powders with least grain growth. ECAP (Equal channel angular pressing) was used for the powder consolidation. We investigated the consolidation, plastic deformation and microstructure evolution behavior of the metallic powders during ECAP using an experimental method. It was found that high mechanical strength could be achieved effectively as a result of the well bonded powder contact surface during ECAP process of gas atomized Al-Si powders.

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스마트 무인기 시스템 요건 도출 (Generation of System Requirements for Smart UAV)

  • 이정진
    • 시스템엔지니어링학술지
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    • 제1권1호
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    • pp.32-38
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    • 2005
  • This paper presents the brief generation process of system requirements for Smart UAV from a development objective. The current Smat UAV requirements deal with the restricted life cycle from development to test and verification exclusive of full life cycle because of the new technology demonstration research program funded by governments. The Smart UAV system consists of flight vehicle, avionics, communication link, payload, ground control station and ground supporting system. In this paper, top-down flown requirements are introduced how to allocate to each sub-system.

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A Study on Building the Regional Cluster: The Case of Fire and Emergency Industrial Cluster in Samcheok-si

  • Lee, Dong-Kyu;Yang, Gi-Geun
    • International Journal of Contents
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    • 제5권3호
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    • pp.57-64
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    • 2009
  • Korea has relied on top down development method, in which companies, research and education institutions move into the industrial complexes established by the government. However, to improve local competitiveness, the paradigm is shifting from the government initiated industrial complex to the clusters based on the cooperative network of the region. Representative case is 'Samcheok-si Fire & Emergency industry cluster construction project' that begun in 2007. AHP technique analysis results on first-stage showed that priority was on policy and network elements, and the results of second-stage analysis show that priority was on Policy incentives to internationalize the cluster and strengthen link,. Cluster branding, Sharing of organizational culture to cope with changes in environment, Creation of group learning culture. The subject of this research is limited to Samcheok-si's the Fire and Emergency Industry cluster formation project. Therefore, the research area and standard should be expanded to increase generality in further researches.

Analysis of SNE Learner's Performance Using NASA Scaling

  • Naveen, A.;Babu, Sangita
    • 한국융합학회논문지
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    • 제5권3호
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    • pp.45-51
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    • 2014
  • Computer science and computing technologies are applied into mathematical, science, medical, engineering and educational applications. The models are used to solve the issues in all the domains. Educational systems are used top down, bottom up, Gap Analysis model in the educational learning system. Educational learning process integrated with Lerner, content and the methodology. The Learners and content are same in the educational system or similar courses but the teaching methodologies are differing one with another. The determinations of teaching methodologies are based on the factors related to that particular model or subject. The learning model influencing determinations are made by the surveys, analysis and observation of data to maximize the learning outcome. This paper attempted to evaluate the SNE learners cognitive using NASA Scaling.

펌프의 자동설계 시스템 개발에 관한 연구 (A Study on the Development of Automatic Drawing System for Pump)

  • 김일수;박창언;정영재;송창재;김학형;박주석
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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    • pp.333-337
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    • 1999
  • The biggest challenge facing today manufacturing industry is better quality and high productivity. From an economic point of view, productivity is the most important parameter, as high productivity will reduce the cost. However, the customers of day are not only cost concerned, but also quality conscious. So high accuracy levels should also be achieved in the manufacturing process. This paper reports the development of a automatic design system based on AutoCAD program. 1'his work is composed of three section that are design of top down menu, impeller and casing for pump programed by AutoLISP language and runned Windows system. The developed system ultimately generates the design for a pump through AutoCAD program. In the design of the pump, it needs about 23 hours with an expert, but this system can be only 80 seconds without an expert.

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