• 제목/요약/키워드: elements

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Mixed 형태의 정식화에 기초한 회전자유도를 가진 변이 평면요소 (Transition membrane elements with drilling freedom based on mixed-type formulation)

  • 최창근;이완훈
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1993년도 가을 학술발표회논문집
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    • pp.8-15
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    • 1993
  • The transition membrane elements with drilling freedom have been developed. The functionals for the linear problem, in which the drilling rotations are introduced as independent variables, have been presented by Hughes & Bressi. And 4-node membrane elements with drilling degrees of freedom were developed by Ibrahimbegovic. The transition elements can be efficiently used in modelling the in-plane structures, in particular, where the stress concentration exists. A modified Gaussian quadrature adopted to evaluate the stiffness matrices of these transition elements which have slope discontinuity of displacement within the elements. Detailed numerical studies show the excellent performance of the transition elements.

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조사시험용 핵연료봉 용접부 비파괴검사에 관한 연구 (A Study on the Non-destructive Inspection for End Closure Welding of Nuclear Fuel Elements for the Irradiation Test)

  • 김웅기;김수성;이철용;이도연;이정원
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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    • pp.302-304
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    • 2004
  • Nuclear fuel elements containing dry recycling nuclear fuel pellets for the irradiation test in a reactor were remotely fabricated from spent PWR fuel materials in a hot cell. End closure welding as well as seal tube welding for thermal sensor of the elements was performed by Nd:YAG laser. The soundness of the end closure welds and seal tube welds for the elements were evaluated by a precise X-ray inspection system composed of a micro-focus X-ray generator with an image intensifier and a real time camera system. Then, helium leak test was performed for the elements. The soundness of the welds of the fuel elements was confirmed by the X-ray inspection and helium leak test. The irradiation test for the fuel elements were successfully completed at the HANARO research reactor.

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국내 병원의 전략에 관한 인식과 구성요소 및 질 수준 평가 (Evaluation on Perception, Elements and Quality of Business Strategy in Domestic Hospitals)

  • 김영훈;김효정;김한성;우정식
    • 한국경영과학회지
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    • 제37권4호
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    • pp.181-196
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    • 2012
  • The purpose of this study is to evaluate of the perception, elements and quality level of business strategy in domestic hospitals. We analyze survey data about strategy. Significantly, we find that domestic hospitals were greatly feeling about the necessity and importance of strategy, but elements and quality level of actual execution strategy is much lower. When evaluating level on the perception, elements and quality of strategy within each of Miles and Snow's strategy type, PA(prospector+analyzer) was higher than DR(defender+reactor). And result of structural equation modeling(SEM), elements had a significant influence on the quality of the strategy, a positive relationship between the components and the PA have been identified. Therefore, we propose that to increase the elements level in order to improve the quality level of strategy, and hospital administrators are need to be PA rather than DR.

서브모델링과 응력선형화를 이용한 압력용기의 안전성 평가

  • 최재훈;김준영
    • EDISON SW 활용 경진대회 논문집
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    • 제4회(2015년)
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    • pp.234-238
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    • 2015
  • When we use a Finite Elements Method (FEM) to solve a linear static analysis problem, number of elements need to be sufficiently small for convergence of the solution. If we analysis a part, whose curvature is varying heavily, we face to determine how small the elements size is, because the calculated stress is increased as the elements are smaller. In this case, we need to analysis with mesh insensitive method, stress linearization. We can get a solution that is not varying with the elements size if the size is smaller than a certain level. In this paper, we evaluate a pressure vessel having geometrical discontinuities using stress linearization. First, we analysis the vessel with global model, including all part of the vessel, using large shell elements. Second, we analysis the local part of the vessel, which is the small part occurring maximum stress, using small continuum elements. Last, we evaluate the safety of the pressure vessel according to the ASME Sec. VIII Div 2.

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삼각형 판 요소의 변위 거동에 대한 비교 연구 (A Comparative Study on the Displacement Behaviour of Triangular Plate Elements)

  • 이병채;이용주;구본웅
    • 전산구조공학
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    • 제5권2호
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    • pp.105-118
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    • 1992
  • Static performance was compared for the triangular plate elements through some numerical experiments. Four Kirchhoff elements and six Mindlin elements were selected for the comparison. Numerical tests were executed for the problems of rectangular plates with regular and distorted meshes, rhombic plates, circular plates and cantilever plates. Among the Kirchhoff 9 DOF elements, the discrete Kirchhoff theory element was the best. Element distortion and the aspect ratio were shown to have negligible effects on the displacement behaviour. The Specht's element resulted in better results than the Bergan's but it was sensitive to the aspect ratio. The element based on the hybrid stress method also resulted in good results but it assumed to be less reliable. Among the linear Mindlin elements, the discrete shear triangle was the best in view of reliability, accuracy and convergence. Since the thin plate behaviour of it was as good as the DKT element, it can be used effectively in the finite element code regardless of the thickness. As a quadratic Mindlin element, the MITC7 element resulted in best results in almost all cases considered. The results were at least as good as those of doubly refined meshes of linear elements.

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중등학교 건축 규모계획 기준에 따른 결정인자 분석에 관한 연구 (A Study on the Architectural Planning Criteria and Factors for Secondary Schools)

  • 맹준호
    • 교육녹색환경연구
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    • 제2권2호
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    • pp.35-51
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    • 2002
  • This study is on the architectural planning and factors for secondary schools. The methods in the approach to the results were settled. A sample of factors that affect architectural scale design were drawn from architectural design direction for a secondary school architectural scale estimation direction. These factors arc broken into primary elements and situational elements. Primary elements include students, teachers, and time. Situational elements include public use percentage, classroom percentage, unit area, coefficient of utilization, etc. The 7 architectural planning criteria to cover changes of various architectural scale design elements are the following; 1) consideration of students selection percentage, 2) consideration of the number of teachers, 3) a variety of possible classrooms, 4) organic operation, 5) efficient time management, 6) consideration of different teaching method depending on subjects, 7) coefficient of utilization with flexibility.

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의류 점포의 VMD 구성 요소와 관련 변인 연구 (A Study on the Relationship between VMD Structural Elements of Apparel Stores and Related Variables)

  • 김선희
    • 복식문화연구
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    • 제15권4호
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    • pp.726-736
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    • 2007
  • The purpose of this study was to identify VMD structural elements of apparel stores, and related variables. The related variables are contained shopping orientation, store types, consumer satisfaction and the intention to purchase in apparel stores. The data was collected from a questionnaire conducted on 378 female adults and was analyzed by frequency analysis, factor analysis, cluster analysis, ANDVA, regression, Duncan test, and reliability analysis. The results were as follows: (1) VMD structural elements of apparel store consisted of four factors: coordination/fitness, fashionability, attractiveness, and functionality. Shopping orientation consisted of six factors: recreational, rational, fashion oriented, convenience oriented, price conscious, and brand conscious. Shopper types consisted of four groups: recreational type shopper, economic type shopper, high involved shopper, and convenience oriented shopper. (2) Significant differences were find out between those shopper types and VMD structural elements. Significant differences were find out between store types and VMD structural elements. (3) VMD structural elements(coordination/fitness, functionality, fashionability) were influenced consumer satisfaction and the intention to purchase.

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Comparison of TDC Circuit Design Method to Constant Delay Time

  • Choi, Jin-Ho
    • Journal of information and communication convergence engineering
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    • 제8권4호
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    • pp.461-465
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    • 2010
  • This paper describes the design method of Time-to-Digital Converter(TDC) to obtain the constant delay time and good reliability. The reliability property is described with delay elements. In TDC the time signal is converted to digital value which is based on delay elements for the time interpolation. To obtain the constant delay time, the first and the last delay elements have different structure compared to the middle delay elements. In the first and the last delay elements, the driving ability could be controlled for the different delay time. The delay element can be designed by analog and digital devices. The delay time of the element using analog devices is not sensitive to process parameters than that of the element using digital devices. And the TDC circuit by the elements using analog devices shows better reliability than that by the elements using digital devices also.

엄밀한 동적 요소를 이용한 유한 요소 동적 모델의 개선 (Improvement of the finite element dynamic model by using exact dynamic elements)

  • 조용주;김종욱;홍성욱
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집B
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    • pp.590-595
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    • 2001
  • To improve the modeling accuracy for the finite element method, this paper proposes a method to make a combined use of finite elements and exact dynamic elements. Exact interpolation functions for a Timoshenko beam element are derived and compared with interpolation functions of the finite element method (FEM). The exact interpolation functions are tested with the Laplace variable varied. The exact interpolation functions are used to gain more accurate mode shape functions for the finite element method. This paper also presents a combined use of finite elements and exact dynamic elements in design problems. A Timoshenko frame with tapered sections is tested to demonstrate the design procedure with the proposed method.

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Bi계 세라믹에서 초전도체 특성에 미치는 도우핑 원소의 영향 (Effect of Doping Elements on Superconducting Characteristics in Bi-system Ceramics)

  • 양승호;박용필;김용주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.198-203
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    • 2000
  • This paper investigated the effects of doping elements on the Bi-Sr-Ca-Cu-O ceramics. The doping elements can be classified into four groups depending on their superconducting characteristics in the Bi-Sr-Ca-Cu-O structure. The first group of doping elements(Co, Fe, Ni and Zn) substitute into the copper site and can reduce the critical temperatures of the 2223 and 2212 phases. The second group of doping elements(Y and La) substitute into the Ca site and cause the disappearance of the 2223 phase and increase the critical temperatures in the 2212 phase. The third group of doping elements(P and K) have a tendency to decompose the superconducting phase and reduce the optimal sintering temperature. The fourth group of doping elements(B, Si, Sn and Ba) almost unaffected the superconductivity of the 2223 and 2212 phase.

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