• 제목/요약/키워드: k-covers

검색결과 1,258건 처리시간 0.031초

배전용 절연카바류의 경년특성 분석 (The Analysis of Ageing Characteristics of Insulation Cover Using in Distribution Line)

  • 김동명;송일근;한재홍;이병성;한용회;이태선
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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    • pp.76-78
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    • 2001
  • In this paper insulation cover that being used in distribution line have been evaluated for aging characteristics. For evaluating its aging properties, we dismounted a variety of samples, like insulation covers for termination of deadend clamp, bushing, LA, COS and sleeve, in the fields. we performed mechanical properties test, electrical test, weathering test, etc. of these samples. And these samples are compared with virgin sample. Test results shows the bad mechanical strength in some part of samples. Especially, Insulation covers for the bushing terminations have cracks in the surface of samples.

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Quasi-F 공간과 극소 Quasi-F cover의 역사적 배경 (Historical backgrounds of Quasi-F spaces and minimal quasi-F covers)

  • 김창일
    • 한국수학사학회지
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    • 제18권4호
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    • pp.113-124
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    • 2005
  • 티코노프공간 X에 대하여 C(X)와 $C^*(X)$는 Riesz-공간이다 C(X)가 순서-코시완비일 필요충분한조건은 X가 quasi-F 공간이고, X가 컴팩트공간이며 QF(X)가 X의 극소 quasi-F cover일 때, C(X)의 순서-코시완비화와 C(QF(X))는 동형이다. 본 논문에서는 quasi-F 공간의 정의와 극소 quasi-F cover의 구성에 관한 동기 및 역사적 배경을 살펴본다.

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Key Account Management: Towards a Multidimensional Definition

  • Ahmmed, Kawsar;Noor, Nor Azila Mohd.
    • Asian Journal of Business Environment
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    • 제2권1호
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    • pp.5-13
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    • 2012
  • The aim of this paper is to propose an integrative definition of key account management (KAM) at the organizational level through a content analysis of the existing definitions of KAM available in the business literatures. A representative pool of definitions of key account management was generated through literature review from twenty three journals that covers the divergence of name variety like global account management, strategic account management, national account management, international key account management, key client management, major account management, key customers management and key account management. Relating to the definition of key account management various attributes are identified through content analysis and according to the relevance, profile for each attributes are developed. On the basis of these attributes a diagrammatic and textual definition is proposed that covers the different standpoints and aspects of key account management approach and captures its essence as well. Eventually, several strategic implications are derived that create the field for further empirical investigation.

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청송군 옹점리 일대 암설 사면의 분포와 지형 변화 (The Distribution and Geomorphic Change of Debris Slope at Ongjeom-ri in Cheongsong-gun)

  • 이광률;박한산
    • 대한지리학회지
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    • 제45권3호
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    • pp.360-374
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    • 2010
  • 본 연구는 옹점리 동부의 암설 사면을 대상으로 암설 사면의 분포, 요인, 식생 피복 및 암설 변화에 대해 분석하였다. 이 지역에서 암설 사면 발달의 중요한 요인은 기반암이 단애 형성과 암설 공급에 유리한 규장암이라는 점과 기계적 풍화작용을 촉진시키는 기온의 영하일수가 비교적 길다는 점이다. 암설 사면의 분포 면적은 일사량이 높아서 수분 증발이 활발하여 식생 피복이 불량한, 남사면과 서사면이 북사면과 동사면에 비해 더 넓은 것으로 나타났다. 옹점리 동부의 가 지역에서 식생 피복으로 인해 암설 사면의 면적은 꾸준히 감소하고 있으며, 평균 $431.0m^2/yr$의 식생 피복 면적 증가 속도를 보였다. 그리고 지상라이다를 이용하여 분석한 결과, 나 지역에서는 1년 동안 1~2개의 암설 입자들이 사면 내에서 변위 또는 이동되었다.

UNCERTAINTY AND SENSITIVITY ANALYSIS OF TMI-2 ACCIDENT SCENARIO USING SIMULATION BASED TECHNIQUES

  • Rao, R. Srinivasa;Kumar, Abhay;Gupta, S.K.;Lele, H.G.
    • Nuclear Engineering and Technology
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    • 제44권7호
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    • pp.807-816
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    • 2012
  • The Three Mile Island Unit 2 (TMI-2) accident has been studied extensively, as part of both post-accident technical assessment and follow-up computer code calculations. The models used in computer codes for severe accidents have improved significantly over the years due to better understanding. It was decided to reanalyze the severe accident scenario using current state of the art codes and methodologies. This reanalysis was adopted as a part of the joint standard problem exercise for the Atomic Energy Regulatory Board (AERB) - United States Regulatory Commission (USNRC) bilateral safety meet. The accident scenario was divided into four phases for analysis viz., Phase 1 covers from the accident initiation to the shutdown of the last Reactor Coolant Pumps (RCPs) (0 to 100 min), Phase 2 covers initial fuel heat up and core degradation (100 to 174 min), Phase 3 is the period of recovery of the core water level by operating the reactor coolant pump, and the core reheat that followed (174 to 200 min) and Phase 4 covers refilling of the core by high pressure injection (200 to 300 min). The base case analysis was carried out for all four phases. The majority of the predicted parameters are in good agreement with the observed data. However, some parameters have significant deviations compared to the observed data. These discrepancies have arisen from uncertainties in boundary conditions, such as makeup flow, flow during the RCP 2B transient (Phase 3), models used in the code, the adopted nodalisation schemes, etc. In view of this, uncertainty and sensitivity analyses are carried out using simulation based techniques. The paper deals with uncertainty and sensitivity analyses carried out for the first three phases of the accident scenario.

LED 융합조명 모듈 자동화 조립 시스템의 피더에 관한 구조해석 및 동특성 해석 (Structural and Dynamic Characteristic Analysis of a Feeder for an Automatic Assembly System of an LED Convergent Lighting Module)

  • 추세웅;정상화
    • 한국기계가공학회지
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    • 제16권1호
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    • pp.124-133
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    • 2017
  • In the current lighting market, LEDs that have a high luminous efficiency, a long life and consume less power have emerged as next generation lighting. Owing to various designs and sizes of LEDs, the production process of existing LEDs involves many tasks that require manual labor; hence, the assembly of LEDs necessitates manpower. Because of the use of manpower, the production costs of LEDs increases and production efficiency decreases. Recently, the assembly parts of LEDs have been standardized for minimizing manual labor, and an LED is developed as an LED panel. The automatic assembly system produces LED convergent lighting by assembling two LED panels and one diffusion cover. To increase the production efficiency of the LED convergent lighting module, it is important that the development of a feeder can continuously supply the LED panels is required, and whose design has sufficient stability. The automatic assembly system of the LED convergent lighting module consists of two feeders, which convey LED panels and diffusion covers to a main conveyor, which assembles the lifted panels and covers. In this study, structural analysis and fatigue life for forced loads on the conveyer line of the feeder in the process of lifting LED panels and diffusion covers of each feeder, is analyzed. In addition, the drive of the belt constituting the conveyor line of each feeder is simulated, and the dynamic characteristics of the belt is analyzed using the virtual engineering method.

캐나다 Ontario주와 우리나라 초등학교의 전기, 자기 관련 교육 과정의 비교 연구 (A Comparative Study on the Curriculum on Electricity and Magnetism between in Korean and in)

  • 한무현;김종성
    • 한국초등과학교육학회지:초등과학교육
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    • 제24권5호특별호
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    • pp.620-626
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    • 2005
  • In this study, we conducted a comparative study to investigate the curriculums on electricity and magnetism between in Korean and in Ontario elementary schools in Canada with respect to connectivity and difference among course materials with grades. We compared textbooks that contain the contents about electricity and magnetism, and connectivity in curriculums that were relevant to the science content system in each country. We report the following differences in the curriculums on electricity and magnetism in each country. First, it turns out that science is taught from the first grade in Ontario, while it is taught from the third grade in Korea. Second, Ontario covers electricity and magnetism only in science curriculum, while Korea covers the same topics both in the science and practical arts curriculum. Third, while the curriculum in Korea introduces 'a magnet' in the third grade, 'electricity' in the fourth and the fifth grade, and 'an electromagnet' in the sixth grade, while the curriculum in Ontario covers the concept of energy from the first grade. As the grades go up, the contents of electricity and magnetism tend to be more deepen. It also emphasizes enhancing students' ability that they can communicate what they learn about technology with others, and that they can apply their knowledge to other fields as well. Based on this study of the Ontario curriculum, we suggest that it is necessary for us to n Science curriculum from the first grade, so that the students can learn science from the early grade, without a need to run another subject, like practical arts. We also found that the Korean curriculum has an interesting structure for the young students to learn to apply their knowledge to the real life immediately, based on an idea that the topic of 'Manipulating the electric appliances' in practical arts curriculum moves to the Science.

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INJECTIVE CONVERS UNDER CHANGE OF RINGS

  • Song, Yeong-Moo;Kim, Hae-Sik
    • 대한수학회논문집
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    • 제16권4호
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    • pp.567-572
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    • 2001
  • Wurful gave a characterization of those rings R which satisfy that for every ring extension $R{\subset}S$. Ho $m_{R}$(S, -) preserves injective envelopes. In this note, we consider an analogous problem concerning injective covers.

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