• 제목/요약/키워드: Lead broken

검색결과 51건 처리시간 0.032초

PT철공진의 원인분석 및 현상모의 (Analysis and simulation of PT ferroresonance)

  • 강용철;이병은;정태영;장성일;김용균
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.42_43
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    • 2009
  • Ferroresonance is a resonance condition between a nonlinear iron core of a potential transformer (PT) and a capacitance. It can lead to PT voltages several times the normal equipment ratings, and cause the isolation broken and damage to equipments near the PT. This paper proposes a analysis method of PT ferroresonance in the time domain. Based on the simplified equivalent circuit, a differential equation was found and the flux was calculated when ferroresonance generates. The forced response and natural response were also analyzed. The performance of proposed analysis method was verified with the EMTP-RV generated data. The method can help analysis chaotic ferroresonance and periodic ferroresonance.

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산소 플라즈마 처리에 의한 반도전성 실리콘 고무 표면의 특성변화 (A Study of the Changes of Surface Properties on Semiconductive-Insulating of Silicone Rubber by Oxygen Plasma Treatment)

  • 이기택;황선묵;홍주일;허창수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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    • pp.25-28
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    • 2005
  • This paper was investigated the changes of surface properties of high-temperature-vulcanized(HTV) semiconductive silicone rubber due to oxygen plasma discharge. The modifications produced on the silicone surface by oxygen plasma were accessed using x-ray photoelectron spectroscopy(XPS), contact angle and Scanning Electron Microscope(SEM). The results of the chemical analysis showed that C-H bonds were broken due to plasma discharge and Silica-like bonds (SiOx. x=3~4) increased. It is thought that the above changes lead to the increase of surface energy of high-temperature-vulcanized(HTV) semiconductive silicone rubber. The micromorphology of surface and hydrophobicity due to plasma discharge based on our results were discussed.

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PSCAD/EMTDC를 이용한 임펄스 궤도회로의 계통분석 연구 (A Study on Analysis of Impulse Track Circuit using PSCAD/EMTDC)

  • 박기범;이태훈;류영태;전용주
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.433-441
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    • 2009
  • We have studied a weird phenomenon on the High Voltage Impulse Track Circuit (HVITC). The biggest problem is that can not recognize the fault states, despite the fact the rail is broken. This study has shown that current HVITC systems can be operated even an ill-contact state of impedance bond lead wire. This study was carried out using various methods, such as measurements using an oscilloscope with voltage and current probes, simulations using PSCAD/EMTDC software tool, and analysis of measured data. Especially, we have simulated the fault state through bypass circuits using PSCAD/EMTDC software tool. We made a model of track circuit and simulated various types of fault states.

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레일 개구부에서의 궤도-차량 상호작용에 대한 연구 (A Study of Dynamic Behavior of Track and Train Interaction on Rail Open Gap)

  • 강윤석;강영종;양신추;조선규;한상윤
    • 한국강구조학회 논문집
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    • 제19권4호
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    • pp.345-355
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    • 2007
  • 장대레일은 동절기에 기온하강으로 인한 인장력을 발생하는데 중위온도 이하로 떨어져 파단이 발생되면 인장파단과 레일 간에 틈이 발생되며 이를 개구부라 한다. 이 개구부를 차륜이 통과하면 충격하중이 발생하며, 큰 손실이 발생할 수 있는 열차탈선이 발생할 수 있다. 본 연구에서는 동적해석을 위해 개구부를 가진 궤도와 차량의 상호작용을 고려한 동적해석모델을 제안하였다. 궤도와 차량의 선형시스템은 비선형 헤르찌안 접촉 스프링에 의해 연성되었으며 전체 궤도-차량 시스템 운동방정식을 정식화하였다. 그리고 개구부에서의 상호작용 현상을 고려하여 궤도 불균일부의 함수를 정의하고 개구부에서의 전후방 레일 사이의 개구량을 고려하였다. 비선형 방정식을 풀기위해 동적해석은 수정된 Newton-Raphson 방법에 근거한 Newmark - $\beta$ 방법에 의해 수행되었다. 그리고 차량속도, 개구량, 레일지지강성에 따른 매개변수를 조건으로 수치해석을 수행하였다.

매연저감장치 손상에 기인한 차량화재 사고사례 분석 (Analysis on Vehicle Fires Caused by Damage of Diesel Particulate Filter (DPF))

  • 송재용;사승훈;남정우;조영진;김진표;박남규
    • 한국화재소방학회논문지
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    • 제26권4호
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    • pp.70-76
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    • 2012
  • 본 논문에서는 디젤 승용차량에서 매연저감장치 손상에 기인한 차량화재에 대하여 기술하였다. 디젤 차량에서는 배출가스에 포함되는 입자상 물질을 저감하기 위하여 매연저감장치를 배기계통에 설치하고 있다. 매연저감장치는 입자상 물질의 과다 포집, 재상과정에서의 오류 및 흡기계통 불량 등에 의해 재생과정에서 파손에 이르게 되며, 매연저감장치가 파손되는 경우, 고온의 배출가스가 분출되고, 차량 하부 배기계통의 주변 가연물을 통해 화재로 진전된다. 매연저감장치 손상에 의해 화재가 발생되는 경우, 배기계통 배관 및 머플러 부분에 규산염계 무기화합물이 부착되는 특징을 나타내며, 이 규산염계 무기화합물은 매연저감장치 내부 필터 재료인 세라믹 부분이 손상되는 과정에서 발생된다. 따라서 화재가 발생된 디젤 차량의 경우, 머플러 주변에서 규산염계 무기화합물이 식별되는 경우, 매연저감장치 손상에 기인한 화재로 추정할 수 있다.

국제물품매매에서 매수인의 본질적 계약위반에 관한 최근의 사례 고찰 (A Study on the Recent Cases of Buyer's Fundamental Breach)

  • 하강헌
    • 무역상무연구
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    • 제55권
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    • pp.95-124
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    • 2012
  • Referring to Buyer's obligations, the Buyer must pay the price for the goods and take delivery of them as required by the contract. There are vital importances to the Buyer's Fundamental Breach. The legal effects of a breach of contract do not depend on the nature of the obligation broken, but on the consequences of the breach the detriment to the other party. The obligations mentioned to Article 53 are primary obligations which are to be fulfilled in the normal performance of the contract. They include a number of different acts which could be seen as the subject-matter of different obligations. CISG gives further details for the payment of the price in Articles 54 to 59 and for taking delivery in Article 60. The buyer has to take delivery at the respective place within a reasonable period after this communication since he cannot be required to take delivery immediately. Refusing to take delivery in case of delay not constituting a ground for avoiding the contract makes no sense, since this would lead to even later delivery. For the understanding of Buyer's Fundamental Breach, We need to search the Cases referring to the breach of buyer's main obligations.

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SMD의 위치와 방향 계산 및 검사 알고리듬 : 형태학적 방법과 Hough 변환 방법의 비교 (Positioning and Inspection of SMD : Comparison of Morphological Method and Hough Transform Method)

  • 권준식;최종수
    • 전자공학회논문지B
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    • 제32B권1호
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    • pp.73-84
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    • 1995
  • New morphological positioning algorithm and inspection method are presented and compared with a method by means of the Hough transform. The positioning algorithm is the process of finding the center and the rotated angle of the surface mounted device (SMD). The inspection method is capable of detecting the location of broken or bent leads. In order to obtain the center and the orientation of the SMD rapidly, the Hough transform method utilizes feature points (concave points) and is executed on a DSP board. The proposed morphological method is implemented by using the morphological skeleton subsets, and an ultimate orientation is decided by the Hit-or-Miss transform (HMT). In the inspection process, two inspection methods also are presented. The first method utilizes the morphological methods, i.e., opening and closing. It is performed before the positioning process and called an initial inspection. The second method follows the positioning process and is performed by an inspection of intersections of rulers and the lead edge (or the skeleton). It is a ruling technique which is referred to as a detailed inspection. We find the morphological approach is preciser and faster than the Hough approach by the comparison of the proposed algorithms.

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러시아 구성주의(Constructivism) 예술의상 연구 - Tatlin, Rodchenko, Stepanova와 Popova를 중심으로 - (A Study on the Costume of Arts in the Russian Constructivism - Focused on Tatlin, Rodchenko, Stepanova & Popova -)

  • 박윤정
    • 복식문화연구
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    • 제18권3호
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    • pp.550-558
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    • 2010
  • Russian Constructivism, which took the lead in the Russian trend of art until the late 1920's, was influenced by European Cubism and Futurism. Breaking away from the previous realistic tendency, Russian Constructivism, to meet the ideology of the revolution, insisted the "Art into Street" and the "Art in Industry" with its abstract and geometric design. Russian Constructivism effected paintings of mid 1920's, as well as Industrial design and costume design. This operated remarkable changes in Russian form of costume and textile area. An unusual situation like revolution had provided the social justification to develop a new costume design not for the special class of people, but for the general public. In this atmosphere, the plan of clothing mass production began to progress. Although the Russian Constructivism costume of arts shows the similarity in the trend of fashion and the physical forms of those days, its fundamental idea in manufacturing costumes was 'to create costumes to be possible to mass-produce and to be wearable to anyone regardless of the social class'. Therefore, Constructivism costume of arts pursued dynamism and geometric form through non-objective design that has broken away from the handcrafted and traditional standards of the past. These distinct characteristics served as a momentum to seek costume design based on productivity and functionality.

"황제내경(黃帝內經)"의 사증(死證)에 대한 고찰(考察) (A Study on Sajeung(死證) presented in "Huangjenaegyeong(黃帝內經)")

  • 정창현;백유상;장우창;김도훈
    • 대한한의학원전학회지
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    • 제17권4호
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    • pp.155-170
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    • 2004
  • The word "Sajeung(死證)" in "Huangjenaegyeong(黃帝內經)" includes a warning to lead to death if it is treated wrongly as well as a definite diagnosis saying that it is impossible to care diseases. A disorder condition of the body means that the balance of Eum-yang(陰陽) are broken or O-haeng(五行) doesn't have a good circulation. The prediction to progress is very important as much as decision of whether it is Sajeung or not because it can be changed by the time of day or night and also by changes of the seasons. In addition, according to the relations between Sangsaeng(相生) and Sanggeuk(相克) of O-haeng patients' diseases fall into a dangerous condition at the time under control. But sometimes it can be a severe illness even they are full of vigor. When living and dying has to be determined, it is emphasized the significance of inspection, auscultation and olfaction, inquiring and palpation(望聞問切法). Especially this is the key point to study people's face and pulse.

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마이크로캡슐에 의한 폴리에스테르 직물의 천연염색에 관한 연구(II) - 황금을 중심으로 - (Natural Dyeing of Polyester Fabric with Microcapsules(II) - Scutellaria baicalensis -)

  • 민경혜
    • 한국의류산업학회지
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    • 제10권6호
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    • pp.1045-1050
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    • 2008
  • Developing of high technology, productivity of the fiber product has being rapidly increased and also various kinds of advanced treatment process lead consumer's needs to more high functional, clean and healthy goods. Moreover, increasing in the concern of eco-friendly material and processing, it has been getting popular that the dyeing method like as using natural dyes is more eco-friendly and natural-friendly treatment process. The method, used in this study, adhesion by binding with micro-capsulized natural material to fabric has low change in quality by external influence and high ability in spray effect by broken capsule which comes to pressure and friction when it dressed. Also it has wide application from natural fiber to synthetic fiber. The purpose of this study is development of multi-functional synthetic material with micro-capsulized Scutellaria baicalensis on PET. Moreover, it was driven by comparison of colormetric properties and fastness between regular dip-dyeing method and binding with micro-capsulized material method. Dye ability was arranged mostly low exhaustion but the PET treated by micro-capsule was more or less better than the dip-dyeing PET. Through the SEM(Scanning Electron Microscope) of PET treated by micro-capsule, it has good residence of capsules even after 5 or 10 times washing. Wash and light fastness was arranged some different grade by each condition but mostly high achievement and the micro-capsulized PET was more improved than regular dip-dyed PET.