• Title/Summary/Keyword: BEF

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BEF Detection Algorithm to Improve Reliability of Three-Wire-Unigrounded Distribution Line (3선-단접지배전선로의 신뢰도개선을 위한 BEF 검출 알고리즘)

  • Wan-Ki Min;Myeong-Ho Yoo;Seong-Hwa Kang
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.166-172
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    • 1997
  • The BEF on the radial distribution line refers to a class of ground faults in which the load-side power line only is grounded, with the distribution line broken into two parts, the source-side and the load-side. Because its mechanism is remarkably different from that of other earth faults, the fault current is very low, and then difficult to detect the BEF. Thus, it is necessary to analyze its properties and to find an appropriate method that can economically protect the BEF of nonautomation area in the substation. As a result of analyzing the BEF data obtained by the RTDS, EMTP simulation, and the field test data of ETSA, we believe that it is the dominant factor in distinguishing the BEF from normal conditions by a criterion value that is appropriately handled from the zero-sequence current. Thus, with this criterion value, a BEF detecting algorithm is constructed which measures the variations of the zero-sequence current and processes then properly so as to make the fault decision. To prove the accuracy of this algorithm, it is compared with the field test data of ETSA under various conditions. The results show that the proposed algorithm is accurate.

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Closure of Bronchoesophageal Fistula with Tissue Adhesive Tisseel - 2 cases report - (조직접합제를 이용한 기관지식도루 폐쇄술 -치험2예-)

  • Lee, Du-Yeon;Yun, Chi-Sun;Hong, Seung-Rok
    • Journal of Chest Surgery
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    • v.24 no.5
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    • pp.470-474
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    • 1991
  • This BEF will be resolved with tissue adhesive application The bronchoesophageal fistula[BEF] is a rare lesion in thoracic surgical diseases & is difficult to be closed surgically. Tissue adhesives has been used widely in surgical fields, or in endoscopy, for some time and seems to be potentially useful in cardiothoracic surgery. We have experienced the closure of BEF with tissue adhesive Tisseel in 2 cases recently. One is 60 years old male who had taken the closure of BEF with Tisseel through right bronchotomy. The other is 57 years old female who had taken the closure of BEF with Tisseel with flexible gastrofiberscopy. The postoperative courses are uneventful for 4 months to now.

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The Overstrain of Thick-Walled Cylinders Considering the Bauschinger Effect Facto. (BEF)

  • Ghorbanpour, A.;Loghman, A.;Khademizadeh, H.;Moradi, M.
    • Journal of Mechanical Science and Technology
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    • v.17 no.4
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    • pp.477-483
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    • 2003
  • An independent kinematic hardening material model in which the reverse yielding point is defined by the Bauschinger effect factor (BEF) , has been defined for stainless steel SUS 304. The material model and the BEF are obtained experimentally and represented mathematically as continuous functions of effective plastic strain. The material model has been incorporated in a non-linear stress analysis for the prediction of reverse yielding in thick-walled cylinders during the autofrettage process of these vessels. Residual stress distributions of the independent kinematic hardening material model at the onset of reverse yielding are compared with residual stresses of an isotropic hardening model showing the significant effect of the BEF on reverse yielding predictions. Critical pressures of direct and reverse yielding are obtained for the most commonly used cylinders and a range of permissible internal pressures for an efficient autofrettaged process is recommended.

Congenital Broncho-esophageal Fistula Diagnosed on Chest CT in Adults - 2 Cases of Surgical Treatment - (흉부전산화단층촬영으로 진단한 성인의 선천성 기관지-식도루 - 수술치험 2예-)

  • 조민섭;조덕곤;송소향;김치홍;안명임;정연주;유진영;조규도
    • Korean Journal of Bronchoesophagology
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    • v.9 no.2
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    • pp.65-68
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    • 2003
  • Recently we successfully treated two cases of congenital bronchoesophageal fistula(BEF), communicating esophagus and right lower lobe, in adults by fistulectomy and right lower lobectomy. The fistulas were initially diagnosed on chest CT examination and confirmed by endoscopy and esophagography. The diagnosis of BEF is usually made by barium esophagography, esophagoscopy, and bronchoscopy. Although congenital BEF presented in adult life is a rare disorder, careful examination of chest CT films would disclose more cases of it , we think , than expected.

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Surgical Treatment of Postoperative Leakage with Pedicled Omental Flap (유경성 대망이식편을 이용한 술후 식도천공 치험1례)

  • Im, Chang-Yeong;Kim, Yo-Han;Yu, Hoe-Seong
    • Journal of Chest Surgery
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    • v.26 no.4
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    • pp.325-328
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    • 1993
  • The pedicled omental flap has been used for treatment of various kind of complications in thoraxcic surgery. Its property of promoting neovascularization , immunilogic properties that limiting the spread of infection, providing soft tissue coverage are very effective in treatment esophageal fistulas. Also, congenital broncho-esophageal fistula [ BEF ] is a rare disease entity which was reported about 100 cases around the world. We experienced 27 years old female patient with Braimbridge type I congenital BEF. We performed division of BEF using stapler and pericardial patch coverage of esophageal side with concomittent left lower lobectomy. This patient was complicated with postoperative esophageal leakage with empyema thoracis. We have successfully managed these problems with re-thoracotomy and re-closure of esophageal fistula using Right Gastroepiploic Artery based pedicled omental flap wrapping around the esophageal anastomosis site. It is felt that pedicled omental flap is a very effective method to manage esophageal complication such as postoperative esophageal leakage.

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Business Event Framework to Support Effective Development of RFID Application (RFID 응용프로그램의 효율적 개발을 지원하기 위한 Business Event Framework)

  • Lee Chanyoung;Kim Youngbong;Moon Mikyeong;Yeom Keunhyuk
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11b
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    • pp.496-498
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    • 2005
  • RFID 응용프로그램은 필요한 기능을 수행하기 위하여 하위의 ALE Interface를 이용하거나 EPCIS 등의 외부 시스템과 통신을 해야 한다. 이러한 동작을 수행하기 위하여 해당 응용프로그램 개발자는 하위 ALE Interface를 사용하기위한 방법과 다른 추가 시스템의 사용법을 배워야 하고 정해진 통신 방법에 따라 프로그램을 작성해야 한다. 이러한 작업은 RFID에 대한 지식수준과 프로그래밍 실력에 따라 많은 시간과 노력을 필요로 하게 된다. 본 논문에서는 이러한 RFID 응용 프로그램 개발 시의 어려움을 최소화 하고자 Business Event Framework(BEF)을 제안한다. BEF는 비즈니스 로직과 직접적으로 관련이 없는 부분은 BEF가 직접수행하고 응용프로그램에서 꼭 필요한 이벤트만을 반을 수 있도록 지원하는 라이브러리이다.

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Luminance Normalization of Optical Sheets in a Backlight Unit for LCD-TVs (LCD-TV용 백라이트 광학시트의 휘도 정량화)

  • Jeong, Jong-Mun;Kim, Jung-Hyun;Shin, Myeong-Ju;Lee, Mi-Ran;Chung, Jae-Yoon;Jeong, Hee-Suk;Kim, Jin-Sheon;Hong, Byeong-Hee;Kang, June-Gill;Cho, Guang-Sup
    • Journal of the Korean Vacuum Society
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    • v.16 no.6
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    • pp.424-432
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    • 2007
  • Luminance properties of external electrode fluorescent lamps and optical components in backlight unit (BLU) and optical transmission rates of optical sheets, are investigated for LCD-TV of 32" in diagonal with WXGA level resolution (1366$\times$768). The luminance is measured in 12-lamps and 18-lamps of BLU. The luminance uniformity preserves about 85 % in the 12-lamps backlight, while the luminance of optical components and the efficiency of backlight in the 12-lamps are lower than those in the 18-lamps backlight. When the lamp luminance in BLU having 12-lamps and 18-lamps is normalized as 100 %, the relative luminance of a diffusion plate, a diffusion sheet, a prism sheet (BEF), a polarization sheet (DBEF), has a constant value without dependence on a lamp luminance. The relative luminance of optical components in 12-lamps BLU is lower than that in 18-lamps backlight. The light transmission rate, the relative luminance of liquid crystal display panel with the luminance 100 % of backlight, is 7.14 % in the use of DBEF and BEF, 6.12 % in the use of only DBEF, and 3.21 % in the use of only BEF. Those Data obtained in this experiment for the lamps and optical components, are the design parameters for the LCD backlight.

An Analysis of Axisymmetric Cylindrical Shell by the Leading Matrix Method (인도행렬에 의한 축대칭 원통형 쉘의 해석)

  • 이관희;박준용;김우중
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.2
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    • pp.193-201
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    • 2004
  • The aim of this study is focused on getting an almost exact solution which is the simplicity and exactness of an axisymmetrically loaded cylindrical shell. This method replaces the finite element method which is a very powerful tool for analysis of any kind of structure which has an arbitrary shape, but is still a numerical analysis. Instead, this study uses the method of distribution of end actions which is a kind of iteration technique to implement the leading matrix method. The distribution and carry-over factors of a cylinder are calculated by the theory of a differential equation of a beam on an elastic foundation. The results are satisfactory when this method is applied to a cylinder that is subjected to a concentrated load and hydrostatic pressure when compared with the BEF analogy separately.

Improvement of on-axis luminance by optimization of edge-lit backlight optic (LCD 에지형 백라이트 광학계의 휘도집광 효율 향상에 관한 연구)

  • Joo, Byung-Yun;Hong, Joo-Pyo
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.95-98
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    • 2009
  • This paper dealt with the design guide of the conventional edge-lit backlight optic with which the on-axis luminance could be increased by trying to improve the light condensing efficiency of a bright enhancement film (BEF). First, the general design guide concerned with the backlight optic was proposed, and then its validness was experimentally proved by conducting design examples with haze controls of both diffuse film and microdot material printed on the backside of the light guide plate. Experimental results showed that the variation range of the on-axis luminance by the present approach was about $5{\sim}9%$, which would be by no means negligible in the practical application.

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Failure Analysis Model for Tensioned FRP Dowels (인장을 받는 FRP 다우일의 파괴 해석 모델)

  • 박상렬
    • Magazine of the Korea Concrete Institute
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    • v.10 no.2
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    • pp.137-146
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    • 1998
  • 본 연구에서는 콘크리트 속에서 인장과 전단을 받는 FRP 다우얼의 거동과 파괴를 예측할 수 잇는 수리적인 파괴 해석 모델을 개발하였다. 다우얼 파괴해석 모델은 다우얼 작용과 파괴기준에 대한 두 개의 하위 모델로 구성되어 있는데 이들을 수정, 결합하여 만들어졌다. 다우얼 작용에 대한 모델로는 BEF 모델을 기초로 하여 두가지의 지수를 새로이 정의, 사용하였는데 하나는 콘크리트지지 강성을 변화시키기 위한 변위 정도 지수이고 다른 하나는 긴장된 케이블의 반력을 고려하기 위한 인장 지수이다. 인장과 전단이 작용하는 FRP다우얼의파괴 모델로는 Tsai-Hill 파괴기준이 사용되었고 이 기준을 적용하기 위하여 파괴 계수를 정의하였다. 개발된 파괴 해석 모델은 긴장된 FRP다우얼의 극한 전단력과 극한 변위를 예측하는데 사용하였고, 해석결과는 여러 인장응력을 가진 FRP 다우얼의 시험결과와 비교하였다.