• 제목/요약/키워드: electrical tree

검색결과 591건 처리시간 0.026초

저밀도 폴리에틸렌의 방사선 조사에 따른 전기 트리 특성 변화 (Radiation Effects on Electrical Treeing Characteristics of Low Density Polyethylene)

  • 이청;신희경;김기엽;박수길;류부형
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1992-1994
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    • 1999
  • Dicumyl peroxide (DCP) is used for crosslinking agent in general. And the correlation between polyethylene and DCP is significant in particular radiation environment. On this paper, The effects on $Co^{60}{\gamma}$-ray irradiation of polyethylene doped dicumyl peroxide(DCP) were investigated. We experimented on electrical properties as following; electrical tree inception and growing type for applying AC step voltage, AC breakdown strength, volume resistivity, capacitance and dissipation factor at high frequency as increasing dosage. Also, chemical analysis was performed TGA, gel content.

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아날로그 홉필드 신경망의 모듈형 설계 (Modular Design of Analog Hopfield Network)

  • 동성수;박성범;이종호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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    • pp.189-192
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    • 1991
  • This paper presents a modular structure design of analog Hopfield neural network. Each multiplier consists of four MOS transistors which are connected to an op-amp at the front end of a neuron. A pair of MOS transistor is used in order to maintain linear operation of the synapse and can produce positive or negative synaptic weight. This architecture can be expandable to any size neural network by forming tree structure. By altering the connections, other nework paradigms can also be implemented using this basic modules. The stength of this approach is the expandability and the general applicability. The layout design of a four-neuron fully connected feedback neural network is presented and is simulated using SPICE. The network shows correct retrival of distorted patterns.

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Predictive Control for Electrical Drives-A Survey

  • Kennel Ralph;Linder Arne
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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    • pp.746-750
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    • 2001
  • During the last decades several proposals have been made in literature to use predictive control for inverter control-especially in electrical drives. These algorithms are completely different to the recursive but linear predictive algorithms known from information theory, where closed mathematical equations are used (e.g. Kalman-filters). Only few of the presented schemes have been realized in industrial applications so far. After some further progress, however, the advantage of predictive algorithms might lead to an increased number of industrial implementations in the future. Besides the common basic idea - to use the well-known but strongly non-linear behaviour of inverters to precalculate the best switching times - there are many differences in the details of these proposals. This contribution shows similarities and differences and attempts to design a 'family tree' of predictive control algorithms. This might grow to a first step to a theoretical approach to deal with predictive control schemes in a more generalised way.

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Dynamic Programming을 적용한 트리구조 미로내의 목표물 탐색 알고리즘 (Target Object Search Algorithm under Dynamic Programming in the Tree-Type Maze)

  • 이동훈;윤한얼;이동욱;심귀보
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2005년도 추계학술대회 학술발표 논문집 제15권 제2호
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    • pp.389-392
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    • 2005
  • 어떤 미로환경 내에서 로봇이 스스로 목표물을 찾기 위해서는 탐색경로를 결정하는 알고리즘이 요구된다. 본 논문에서는 'Y'형 미로에서 목표물을 탐색하기 위하여 Dynamic Programming을 적용한 미로 탐색 알고리즘을 제안한다. 실험에서는 규격화된 미로 블록을 만들고, 먼저 기존에 연구 되었던 자수법 알고리즘을 자율이동 로봇에 적용해 'Y'형 미로 블록을 탐색하게 한다. 그리고 본 논문에서 제시한 Dynamic Programming을 이용한 미로탐색 알고리즘을 자율이동로봇에 적용하고 미로를 탐색한 후 이두가지 알고리즘을 적용한 로봇의 주행 결과를 각각 비교해 봄으로서 Dynamic Programming을 적용한 자율이동로봇의 미로탐색 방법의 성능을 확인한다.

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변전설비의 구조적 중요도와 고장 분석을 통한 유지보수 우선순위 선정 (Decision of Maintenance Priority Order for Substation Facility through Structural Importance and Fault Analysis)

  • 이성훈;이윤성;김진오
    • 조명전기설비학회논문지
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    • 제27권4호
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    • pp.23-30
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    • 2013
  • Reliability Centered Maintenance(RCM) is one of most widely used methods in the modern power system to schedule a maintenance cycle and determine the priority of inspection. A precedence study for the new structure of rearranged system should be performed due to introduction of additional installation. This paper proposes a new method to evaluate the priority of maintenance and inspection of the power system facilities. In order to calculate that risk index, it is required that the reliability block diagram should be analyzed for the power system. Additionally, a fault cause analysis is also performed through the event-tree analysis.

벡터 양자화에서 벡터의 특성을 이용한 단축 탐색방법 (A Simple Algorithm for Fast Codebook Search in Image Vector Quantization)

  • 고종석;김재균;김성대
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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    • pp.1434-1437
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    • 1987
  • We present a very simple algorithm for reducing the encoding (codebook search) complexity of vector quantization (VQ), exploiting some features of a vector currently being encoded. A proposed VQ of 16 (=$4{\times}4$) vector dimension and 256 codewords shows a slight performance degradation of about 0.1-0.9 dB, however, with only 16 or 32 among 256 codeword searches, i.e., with just 1/16 or 1/8 search complexity compared to a full-search VQ. And the proposed VQ scheme is also compared to and shown to be a bit superior to tree-search VQ with regard to their SNR performance and memory requirement.

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액체$N_2$중 절연재료의 부분방전 열화 연구 (Study of Partial Discharge Degradation of Insulating Materials in Liquid Nitrogen)

  • 김현희;김상현;마대영;장종근;남궁도;조전욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.406-410
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    • 1995
  • A superconducting cable is one of the promising methods of undground transmission of high electric power in the future. It is very important that composite insulation system of $LN_2$ and polymer films takes into consideration for application high $T_c$ superconductor. This study is about both the partial discharge and properties V-t in $LN_2$. As result, applied voltage doesn't depend on the radius of non-eroded area but eroded area. And eroded area is observed the formation such as the ring of a tree.

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CART 알고리즘과 하이브리드 학습을 통한 뉴로-퍼지 시스템과 응용 (Neuro-Fuzzy System and Its Application Using CART Algorithm and Hybrid Parameter Learning)

  • 오봉근;곽근창;유정웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 B
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    • pp.578-580
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    • 1998
  • The paper presents an approach to the structure identification based on the CART (Classification And Regression Tree) algorithm and to the parameter identification by hybrid learning method in neuro-fuzzy system. By using the CART algorithm, the proposed method can roughly estimate the numbers of membership function and fuzzy rule using the centers of decision regions. Then the parameter identification is carried out by the hybrid learning scheme using BP (Back-propagation) and RLSE (Recursive Least Square Estimation) from the numerical data. Finally, we will show it's usefulness for fuzzy modeling to truck backer upper control.

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통계적 기법을 이용한 전력 케이블 절연층(XLPE)의 수명 예측 (Life Expectancy for Power Cable Insulation(XLPE) Using Statistical Method)

  • 이승엽;조대희;이인호;박완기
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.57-61
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    • 1999
  • Electrical stress makes insulating materials aged finally resulting in the dielectric failure. It becomes more and more important to recognize the degree of aging and the life time of the insulating materials since it is directly concerned with the reliability of the insulation system. In this paper, the life time of the Cross-linked Polyethylene(XLPE), the insulation layer in the 154kV-grade power cable, is expected and calculated using statistical and mathematical methods. The simulated results are compared with experimental ones and the life exponent of the material is obtained.

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직류 전계하 LLDPE/EVA혼합필름의 절연파괴특성

  • 고시현;김형주;이종필;신현택;이충호;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.65-68
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    • 2000
  • Polyethylene, has long history and is widely used, was researched due to good electrical properties by many authors. But PE under stress has the critical defects of space charge accumulation and tree growth, so various methods such as catalyst, additives and blend to improve these problems have been execute, of which we selected blending method. As in our previous papers we investigated electrical conduction, dielectric and AC dielectric breakdown characteristics, we did DC dielectric breakdown characteristics in this paper. We selected pure LLDPE, pure EVA and LLDPE films mixed with EVA as specimens, which were mixed with the weight percentages of 50, 60, 70 and 80[wt%] to be thin film. DC applying voltage speed was 500[V/sec]. The relation between dielectric breakdown characteristics and the variations of super structure due to mixing was investigated, and especially trap level at amorphous region, threshold energy increment of conductive electron at free volume were considered.

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