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내압과 굽힘의 복합하중에서 내부 감육배관의 손상기준 (Criterion for Failure of Internally Wall Thinned Pipe Under a Combined Pressure and Bending Moment)

  • 김진원;박치용
    • 한국안전학회지
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    • 제17권4호
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    • pp.52-60
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    • 2002
  • Failure criterion is a parameter to represent the resistance to failure of locally wall thinned pipe, and it depends on material characteristics, defect geometry, applied loading type, and failure mode. Therefore, accurate prediction of integrity of wall thinned pipe requires a failure criterion adequately reflected the characteristics of defect shape and loading in the piping system. In the present study, the finite element analysis was performed and the results were compared with those of pipe experiment to develop a sound criterion for failure of internally wall thinned pipe subjected to combined pressure and bending loads. By comparing the predictions of failure to actual failure load and displacement, an appropriate criterion was investigated. From this investigation, it is concluded that true ultimate stress criterion is the most accurate to predict failure of wall thinned pipe under combined loads, but it is not conservative under some conditions. Engineering ultimate stress estimates the failure load and displacement reasonably for al conditions, although the predictions are less accurate compared with the results predicted by true ultimate stress criterion.

유체-구조물 상호작용을 위한 유한요소 결합공식화의 예조건화에 대한 연구 (Preconditioning Method of a Finite Element Combined Formulation for Fluid-Structure Interaction)

  • 최형권
    • 대한기계학회논문집B
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    • 제33권4호
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    • pp.242-247
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    • 2009
  • AILU type preconditioners for a two-dimensional combined P2P1 finite element formulation of the interaction of rigid cylinder with incompressible fluid flow have been devised and tested by solving fluid-structure interaction (FSI) problems. The FSI code simulating the interaction of a rigid cylinder with an unsteady flow is based on P2P1 mixed finite element formulation coupled with combined formulation. Four different preconditioners were devised for the two-dimensional combined P2P1 finite element formulation extending the idea of Nam et al., which was proposed for the preconditioning of a P2P1 mixed finite element formulation of the incompressible Navier-Stokes equations. It was found that PC-III or PC-IV among them perform well with respect to computational memory and convergence rate for some bench-mark problems.

석탄가스화 복합화력 발전용 가스터빈 성능해석 (Performance Analysis of a Gas Turbine for Integrated Gasification Combined Cycle)

  • 이종준;차규상;손정락;김동섭
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.771-774
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    • 2007
  • Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed with hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of the syngas to the performance of a gas turbine in a combined cycle power plant. For this purpose, a commercial gas turbine is selected and its performance characteristics are analyzed with syngas. It is found that different heating values of those fuels and chemical compositions in their combustion gases are the causes in the different performance characteristics. Also, Changing of turbine inlet Mass flow lead to change the turbine matching point, in the event the pressure ratio is changed.

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기공외기요법(氣功外氣療法)의 항(抗) 스트레스 효과(效果) 연구(硏究) (Effects of Kigong Theraphy in Cocentration of Catecholamines and Cortisol and some Tests on Testing-Stressed)

  • 김기옥
    • 대한의료기공학회지
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    • 제1권1호
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    • pp.95-109
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    • 1996
  • To investigate anti-stress effects of Manual Kigong, Manual-Apparatus Combined Kikong, and Systemic Kigong, this experiments were performed changing of plasma catecholaminess and serum cortisol measured. Also using D.I.T.I(Digital Infrared Thermongraphy Imaging), Pulse Analyzer, Electric Current on Neurometer, and Digital Flicker on Testing-Stressed. And following results were abtained. 1) Menual-Appartus Combined Kikong decreased significantly increasing concentration of plasma epinephrine and norepinephrine level in Testing-stressed. 2) Manual Kigong decreased increasing concentration of serum cortisol level in Testing-stressed. 3) Manual Kigong and Manual-Aparatues Combined Kikong increased decreasing thermomerty on the palm's center caused Testing-stressed. 4) All of three treats are small change in SET(Systolic Ejection Time) by Pulse Analyzer caused Testing-stressed. 5) More changes of Electric Current on the Neurometer Diagnosis caused Testing-stressed are as followed. Manual-Apparatus Combined Kikong >Systemic Kigong >Manual Kigong From the results, it may be concluded that Manual-Apparatus Combined Kikong Theraphy having more anti-stress effects than Manual Theraphy. Systemic Kigong Therapy.

유체-구조물 상호작용을 위한 유한요소 결합공식화의 예조건화에 대한 연구 (Study on the preconditioning method of a finite element combined formulation for fluid-structure interaction)

  • 최형권
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.597-600
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    • 2008
  • Preconditioners for a two-dimensional combined finite element formulation have been devised and tested for fluid-structure interaction (FSI) problems. The FSI code simulating the interaction of a elastic body with an unsteady flow is based on P2P1 finite element combined formulation. It has been shown that two preconditioners among them perform well with respect to computational memory and convergence for a bench-mark problem. Based on the verification of the preconditioners for the two-dimensional combined formulation, four preconditioners are proposed for the problem of an elastic body interacting with a flow.

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도시가로경관요소가 시각적 선호에 미치는 복합적 영향에 관한 연구 (A Study on the Complex Effects of Streetscape Components on Visual Preference)

  • 변재상;정수정;임승빈
    • 한국조경학회지
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    • 제27권2호
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    • pp.9-18
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    • 1999
  • In this study the relative effects among trees, cars, wires and building facades on visual preference are measured with the photo-montage scenes, which were synthesized by computer graphic programs. In addition to these experiments, the interaction of each elements of streetscapes have been investigated. The results of this study can be summarized as follows ; (1) It was found that trees had a remarkable positive effect on preference for streetscapes, wires had a moderate negative effect, cars had a trivial effect and the effects of building facades were medium. (2) It was investigated that the building of residential type was most preferred among commercial, residential, and office building types. The next preferred building facade was the commercial type. (3) The interaction of each element of streetscapes also have effects on preference. Especially, it was found that the combined effects of building-wire and building-cars were more notable than other combined effects of two elements.

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혼합송전계통에서 재폐로 시행시 개폐과전압 해석 (Analysis of Switching Overvoltage on Operating Reclosing in Combined Transmission Systems)

  • 임광식;이종범;정채균;강지원;박흥석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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    • pp.391-393
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    • 2008
  • This paper is analysed by switching overvoltage on operating reclosing in 154 [kV] combined transmission systems. Combined transmission systems are modeled by EMTP/ATPDraw program. It is fault condition that simulate high resistance earth fault. The simulation is carried out considering variation of parameters such as resistance value of fault point and rate of underground line.

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선천성 낭성폐와 동반한 폐동맥판막협착증: 1례 보고 (Congenital Cystic Lung Combined with Pulmonic Valvular Stenosis: A Case Report)

  • 김주이
    • Journal of Chest Surgery
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    • 제10권1호
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    • pp.118-123
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    • 1977
  • Congenital cystic disease of the lung is very rare and controversial disease. But in general is regarded as developmental anomaly. Occasionally failure of the primitive lung bud to develop combined with cardiac anomaly had been reported but it was very rare. Recently a case of cystic lung disease combined with pulmonic valvular stenosis was seen in this clinic with clinical pictures of nonspecific respiratory infection and X-ray finding very similar to that of far advanced pulmonary tuberculosis, destroyed left lung. This case was treated by closed pulmonic valvulotomy and left side pneumonectomy successfully.

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복합간세포-담관암종 : 병리와 분류 (Combined Hepatocellular-Cholangiocarcinoma : Recent Progressin Pathology and Classification)

  • 최준혁
    • Journal of Yeungnam Medical Science
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    • 제28권1호
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    • pp.1-12
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    • 2011
  • Primary liver carcinomas have classified classified into hepatocellular carcinoma, cholangiocarcinoma, and combined hepatocellular-cholangiocarcinoma (CHC). CHC is a tumor containing unequivocal, intimately mixed elements of both hepatocellular carcinoma and cholangiocarcinoma. It forms a small but significant proportion of primary liver carcinomas. The origin and pathogenesis of CHC have not been well established. According to the 2010 WHO classification, CHCs are categorized into 2 groups: the classical type and a subtype with stem cell features. This review describes recent progress in pathology and classification of CHC.

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혹독한 환경에서의 무근콘크리트 복합열화 저감을 위한 배합설계 및 품질관리 방안 구축 (Building mix design and quality control measures to reduce the combined deterioration of plain concrete in harsh environments)

  • 김대건;박찬규
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 추계 학술논문 발표대회
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    • pp.85-86
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    • 2016
  • Recently damages caused by the additional costs and degradation in durability combined deterioration due to plain concrete deterioration has occurred. In particular, in the case of the finish that is not exposed to the outside air in the concrete to respond to the harsh environment (freeze-thawing, calcium laying, etc.), to establish a quality control way for the process and the concrete mix design for it.

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