• 제목/요약/키워드: Relaxation current

검색결과 238건 처리시간 0.034초

복수 수요가로 구성된 공급망의 협력적 주문량 결정 방안 (Cooperative ordering policy in a multiple-retailer supply chain system)

  • 김태복
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2007년도 추계학술대회 및 정기총회
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    • pp.104-107
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    • 2007
  • In this paper, we propose the coordination scheme in a single-manufacturer-multiple-retailer supply chain system. Traditionally, the bargaining power of the single manufacturer is superior to those of retailers. The business environment supported by the e-business scheme may give rise to new business behavior. The multitude of retailer requests the manufacturer to relax the his unilateral lot-sizing policy while they are willing to compensate more than the manufacturer's expected loss caused by abandon his superior bargaining power. The side payment aggregated by the multiple retailers is transferred to the manufacturer according to the degree of the manufacturer's relaxation from the current unilateral lot-sizing policy.

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배전케이블의 열화진단 시험법의 최근 동향 (Recent Trend of the Testing Techniques for Distdibution Cable Diagnosis)

  • 정상진;김일권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.304_306
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    • 2009
  • 본 논문은 IEEE std 400에서 규정하고 있는 케이블 시험방법 중 Type 1, 파괴시험법(DC, 상용주파 내전압, 그리고 VLF내전압 시험)은 절연물 손상을 발생시키므로 예방진단에 사용될 수 없고 그렇지 않은 Type 2. 비파괴시험법에 대해 주로 소개하였다. 이와 추가하여 한전에서 사용 중인 IRC(Isothermal Relaxation Current) 측정법에 대해 간략하게 소개하고 더불어 IEEE Std 400에서 제시하고 있는 $Tan{\delta}$측정법의 문제점 및 개정 방향을 소개하고, 마지막으로 IEEE Std 400.3의 PD신호의 분석을 통해 결함위치와 열화정도를 평가 진단하는 기법에 대해 서술하고저 한다.

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국내 지중배전케이블에 대한 수트리 열화진단기술 현장 시험 결과 (Field Test Results for Water-tree Diagnosis Technologies of Domestic Underground Distribution Cable)

  • 이재봉;정종만;박철배;이재옥;목영수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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    • pp.506-507
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    • 2006
  • 1986년 제조되어 국내 지중배전계통의 관로에서 20년간 사용된 CNCV케이블에 대하여 IRC(Iso-thermal Relaxation Current) 측벙법을 사용하는 진단장비와 0.1Hz 극저주파 Tan-delta 측정법을 사용하는 진단장비로 케이블의 수트리 열화 진단을 시행하고 철거한 후 교류파괴전압시험을 수행하였다 각 진단장비의 진단결과와 교류파괴전압시험 결과, 수트리의 존재여부를 비교하였다. VLF Tan-delta 측정법을 사용하는 진단장비가 교류파괴전압시험결과, 수트리의 유무 둥과 상관성이 비교적 높게 나타났다. 통계적으로 신뢰성을 확보할 수 있도록 지속적인 비교 검증시험을 추진할 계획이다.

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Instability of Electrically Driven Polymer Liquid Jets

  • Lee Min-Hyung;Kang Seung-Baik;Park Joo-Hyuk
    • Journal of Mechanical Science and Technology
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    • 제20권3호
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    • pp.409-417
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    • 2006
  • Polymer nanofibers can be generated by a electrospinning process. The process involves electrically charged jet of polymer solutions evolving from a droplet. The jet stretches in vertical direction due to the difference between charged particle and constant current located at the collector, while the Coulomb and viscoelastic forces start to contribute to radial and azimuthal (torsional) stretching. In this paper, the unstable dynamics of the liquid polymer jet is examined experimentally and theoretically. A complex viscoelastic rheological model has been adopted to analyze the behavior of a charged liquid jet. The model includes complex phenomena of stress relaxation of the liquid jet resulting from the competing force components. The experimental data of the jet paths captured by high-speed videocamera also confirm the similar behavior with the predictions.

서브미크론 MESFET의 DC 특성 (The DC Characteristics of Submicron MESFEFs)

  • 임행상;손일두;홍순석
    • E2M - 전기 전자와 첨단 소재
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    • 제10권10호
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    • pp.1000-1004
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    • 1997
  • In this paper the current-voltage characteristics of a submicron GaAs MESFET is simulated by using the self-consistent ensemble Monte Carlo method. The numerical algorithm employed in solving the two-dimensional Poisson equation is the successive over-relaxation(SOR) method. The total number of employed superparticles is about 1000 and the field adjusting time is 10fs. To obtain the steady-state results the simulation is performed for 10ps at each bias condition. The simulation results show the average electron velocity is modified by the gate voltage.

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Luminescent Properties of Two-Ions Doped Phosphors for LED Application

  • Kim, Tae-Gon;Kim, Young-Sic;Im, Seoung-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.52-55
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    • 2009
  • A red phosphor, $(Sr,Ca)_2P_2O_7:Eu^{2+},Mn^{2+}$, for UV-LED was synthesized under a reducing atmosphere, and its luminescent properties were investigated. The phosphor absorbs ultraviolet light at around 400 nm and efficiently emits red light at approximately 610 nm through an energy transfer from $Eu^{2+}$ to $Mn^{2+}$. Using the varied input current test for the phosphor-loaded LED lamps, it was found that the luminescent efficiency of the phosphor decreased with increasing light flux. This might be due to an increased probability of excited-state absorption and the consequent non-radiative relaxation in $Mn^{2+}$ ions in the condition of high photon influx.

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유전완화와 열자격전류법에 의한 폴리테트라후로루에틸렌의 유전특성 평가 (Estimate of dielectric characteristics on polytetrafluoroethylene by the dielectic relaxation and thermally stimulated current method)

  • 김기준;김경환;홍진웅;이준웅
    • E2M - 전기 전자와 첨단 소재
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    • 제4권4호
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    • pp.322-329
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    • 1991
  • 폴리테트라후로루에틸렌의 유전특성을 규명하기 위해 두께 100[.mu.m]를 시료로 선택하여 온도범위 30-150[.deg.C], 주파수범위 30~3*$10^{5}$[Hz]에서 유전특성과 열자격 전류를 측정하였다. 유전정접은 유리전이온도 부근에서 긴 체인의 마이크로 브라운 운동에 의한 손실로 이때 활성화 에너지는 15.18[kcal/mole]를 얻었으며 열자격전류방법에서 얻은 .betha. 피크의 활성화에너지와 거의 일치함을 확인하였다. 또한 열자격전류방법으로 게산된 유전정접의 크기도 유전특성의 초저주파에서 나타나는 값과 잘 일치됨을 확인하였다.다.

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TV 시청 동기가 식문화 프로그램 시청 선호도 및 시청의도에 미치는 영향 - 식문화 관여도의 조절효과를 중심으로 - (Effects of Viewing Motivations on Viewing Preferences and Viewing Intentions of Television Food Programs)

  • 안세경;이범준
    • 한국식생활문화학회지
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    • 제29권3호
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    • pp.259-269
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    • 2014
  • The current study investigated the relative effects of viewing motivations on viewing preferences and viewing intentions of television food programs. Data collection was conducted by administering a survey to television food program viewers both on and offline. Viewing motivations were categorized as 'information' 'entertainment', 'pass-time', 'companionship', 'relaxation', and 'social interaction'. 'Information' and 'entertainment' proved to be the most important motivational factors affecting viewing preferences for television food programs. 'Information' and 'social interactions' were the strongest predictors of viewing intentions of television food programs. However, 'pass-time' had a negative influence on both viewing preferences and viewing intentions of television food programs. Furthermore, the results of study verified the moderating effects of food involvement in these relations.

배전케이블 진단결과와 교류절연파괴강도의 상관성 (Relation between Dielectric Diagnosis and ACBD Strength in URD Cables)

  • 한재홍;김주용;김동명;이병성;정년호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.484-487
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    • 2000
  • This study is for assessing a reliability of diagnostic device through comparing diagnostic results to ACDB strength. The dielectric diagnosis using IRC (isothermal relaxation current) measurement was carried on service-aged cables. From this study, there was little correlation between dielectric diagnosis and ACBD strength in long distance cables. But the correlation between them showed in short distance below 200 m. Therefore, it is desirable to diagnose the URD cables in short distance.

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주택정원 조성 및 유지관리의 실태와 개선방안에 대한 기초조사 - 충청북도 괴산군 일대를 중심으로 - (A Survey on the Actual Conditions of Housing Garden Creation and Maintenance, to provide suggestions for Improvement - Focused on Goesan-gun, Chungcheongbuk-do -)

  • 유병균;염성진
    • 한국환경과학회지
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    • 제30권9호
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    • pp.741-752
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    • 2021
  • Gardens are known to provide relaxation, including psychological stability and mental rest. Recently, social interest in gardens has been growing in various ways, including the increase of groups sensitive to environmental pollution and a rising interest in the overall management of natural resources. In reality, however, the owners of housing gardens lack fundamental knowledge for creating and maintaining the gardens, directly and indirectly. This limitation presents a number of problems and challenges. Therefore, this study conducted an analysis of various aspects relating to the creation and maintenance of housing gardens, reflecting the sense of ownership. The study aimed to examine the current status, and based on this, it was intended to present improvement measures for practical and efficient creation of housing gardens and their maintenance in the future.