• 제목/요약/키워드: Infinite body

검색결과 114건 처리시간 0.027초

댐-호소계 비선형 지진응답의 직접시간영역 해석기법 (Direct Time Domain Method for Nonlinear Earthquake Response Analysis of Dam-Reservoir Systems)

  • 이진호;김재관
    • 한국지진공학회논문집
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    • 제14권3호
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    • pp.11-22
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    • 2010
  • 이 논문에서는 댐-호소계의 선형 및 비선형 지진응답 해석을 시간영역에서 엄밀히 수행할 수 있는 해석법을 제시하였다. 댐-호소계는 (1) 선형 또는 비선형으로 거동하는 댐체와 (2) 깊이가 균일하다고 가정한 호소 원역 및 (3) 댐체와 호소 원역 사이 불규칙한 형상의 근역의 세가지 부구조물로 구성된 연계 시스템으로 정식화되었다. 댐체는 선형 또는 비선형 유한 요소로 모델링되고, 호소 원역은 무한 영역으로의 에너지 방사를 엄밀하게 표현할 수 있도록 주파수영역에서 개발된 변위기반 전달경계를 시간영역에서의 포갬적분으로 변환하여 시간증분법과 결합이 용이하게 하였다. 호소 근역을 댐체와 호소 원역이라는 두 개의 부구조물 사이에 저장된 압축성 유체로 모델링하였다. 이 논문에서는 세 개의 부구조물로 구성되는 댐-호소계에 대해 비선형 시간영역 해석을 용이하게 하는 시간증분법을 유도하여 제시하였고 개발된 해석법을 다양한 형상의 댐-호소계의 지진응답 해석에 적용하여 그 정확성을 검증하였다. 이에 추가하여 제시한 기법을 콘크리트 댐의 비선형 지진응답 해석에 적용하여 손상 정도와 부위를 해석 결과로서 보여주었으며 동시에 제시한 기법이 내진성능 평가 등 실무에 바로 활용될 수 있음을 입증하였다.

TATTOO의 패션성에 관한 연구 (A Study on the Tattoo Fashion)

  • 정은숙;김향수
    • 복식
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    • 제53권2호
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    • pp.153-169
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    • 2003
  • I think that apparel attaches importance to the degree of satisfaction of visual expression in one ornamental culture in which it is clothed on human body. whereas a tattoo attaches more importance to part of the expression of one's own identity in the same context. However. modern tattooing act was highlighted only as an element of act which was negative in the purpose and the degree of taste or which assumed the grotesque meaning of a particular group. away from pure concepts such as simple ornament or an amulet according to the flow of the world. A tattoo is gradually being seen as one of avant-garde methods of art again these days, and TATTOO LOOK is being popularized as street fashion as an effective method of one's own satisfied desires and peculiar expression of personality. I have got the following conclusions as the result of having studied on a tattoo which is establishing itself as another plastic art that is matchable with the fashion of dress and its ornaments in which human incessant instinctive desire for the ornament of body has been beyond nostalgia for the past and simple ornament which were pure in up-to-date modern society First, a tattoo is of personality. In that it solidifies one's own personality of another side by being transformed, one's own attraction can be transferred to a fashion tattoo with which one can emit one's own personality. Secondly. a tattoo is fashion. As a new body ornament called transformation by a tattoo was emerging, the fashionableness owned by a tattoo had in its area ample room for the fashionableness with which it can coexist with the culture of dress and its ornaments. Thirdly. a tattoo is popularized. TATTOO LOOK in which one's own satisfied desires and the expression of personality are properly applied is being recently transmitted easily everywhere in the world and popularized as street fashion. Fourthly, a tattoo is not depraved art. It's because of the point that a tattoo which had been recognized only as a decadent expression in which avant-garde elements of unknown nationality appeared mixed showed the possibility that it could establish itself as fashion art. If we go on studying and complementing the problems of individual sides about a tattoo also in the future, the infinite fashionableness for the elements called personality. sense and emotion owned by a tattoo suggested ample possibility as future industry to be highlighted.

퇴적 침전구에서 발생하는 내면파 유동에 의한 유체력 해석 (Numerical Computations on the Hydrodynamic Forces by Internal Waves in a Sediment Pocket)

  • 경조현;김장환;배광준
    • 한국해양환경ㆍ에너지학회지
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    • 제7권4호
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    • pp.192-198
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    • 2004
  • 해안 근처에서는 해수보다 무거운 진흙 등으로 채워진 퇴적 침전구가 존재한다. 이러한 퇴적 침전구 내에서는 해양으로부터 들어오는 입사파에 의해 내면파 유동이 발생할 수 있다. 본 논문에서는 내면파 유동이 존재하는 퇴적 침전구 내에 위치한 물체에 발생하는 2차원 내면파 문제에 대한 수치기법을 개발하였다. 수학적 정식화 과정으로 유체 영역을 포텐셜 유동으로 가정하였으며, 자유표면에 대한 경계조건은 선형화된 자유표면 경계조건을 사용하였다. 수치 기법으로는 국소 유한 요소법을 사용하였다. 사용된 국소 유한 요소법은 기지의 함수 집합을 사용하여 방사 경계조건을 엄밀히 만족함으로써 계산 영역을 작게 줄일 수 있는 장점이 존재한다. 개발된 수치 기법의 검증을 위하여 Schwingers의 범함수법을 이용한 Lassiter의 계산 결과와 비교하였으며, 서로 잘 일치함을 확인하였다. 계산 예로서는 퇴적 침전구내에 형성된 내면파면 위에 존재하는 파이프라인이 입사파에 비해 유기 되는 힘을 계산하였다.

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유한요소 교호법을 이용한 삼차원 균열의 탄소성 J 적분 해석 (Analysis of Elastic-Plastic J Integrals for 3-Dimensional Cracks Using Finite Element Alternating Method)

  • 박재학
    • 대한기계학회논문집A
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    • 제33권2호
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    • pp.145-152
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    • 2009
  • SGBEM(Symmetric Galerkin Boundary Element Method)-FEM alternating method has been proposed by Nikishkov, Park and Atluri. In the proposed method, arbitrarily shaped three-dimensional crack problems can be solved by alternating between the crack solution in an infinite body and the finite element solution without a crack. In the previous study, the SGBEM-FEM alternating method was extended further in order to solve elastic-plastic crack problems and to obtain elastic-plastic stress fields. For the elastic-plastic analysis the algorithm developed by Nikishkov et al. is used after modification. In the algorithm, the initial stress method is used to obtain elastic-plastic stress and strain fields. In this paper, elastic-plastic J integrals for three-dimensional cracks are obtained using the method. For that purpose, accurate values of displacement gradients and stresses are necessary on an integration path. In order to improve the accuracy of stress near crack surfaces, coordinate transformation and partitioning of integration domain are used. The coordinate transformation produces a transformation Jacobian, which cancels the singularity of the integrand. Using the developed program, simple three-dimensional crack problems are solved and elastic and elastic-plastic J integrals are obtained. The obtained J integrals are compared with the values obtained using a handbook solution. It is noted that J integrals obtained from the alternating method are close to the values from the handbook.

전단응력하의 분산형 복합재료에 미시역학적인 특성평가 (Analysis for Properties of Particle or Short Fiber Reinforced Composites based on Micromechanics under Pure Shear)

  • 조영태;임광희
    • Composites Research
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    • 제15권3호
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    • pp.11-17
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    • 2002
  • 본 연구에서는 분산형 강화복합재료에 균열이 발생하면 하중부하능력이 감소와 더불어 재료의 손상을 초래할 수 있어 재료의 완전한 게재물과 균열이 존재한 게재물이 있는 경우를 상정하여 하중부하능력과 탄성 음력분포를 평가한다. 무한체가 전단음력을 받을 때 완전한 게재물과 균열이 내재한 경우에 대하여 3차원 유한요소해석이 수행되어 완전한 게재물의 경우는 게재물의 영역의 음력은 동일하고 게재물의 계면은 다소 불균일하게 나타났다. 그리고 균열이 내재한 경우에는 균열주변에는 음력이 집중되는 경우를 볼수 있을 뿐만아니라 아주 복잡한 분포를 볼수 있었다. 불균질물의 평균응력은 하중부하능력으로 표현이 가능하였고 완전만 게재물과 균열의 경우도 균열손상에 의해 하중부하능력의 차이를 볼 수 있었다. 특히, 균열이 내재한 경우에 에스펙터비(aspect ratio)가 증가할수록 하중부하능력이 증가함을 알 수 있었다.

2차원 자유표면파 문제에서의 국소 유한요소법의 응용 (An Application of the Localized Finite Element Method to Two-dimensional Free Surface Wave Problems)

  • 길현권;배광준
    • 대한조선학회지
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    • 제22권3호
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    • pp.9-18
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    • 1985
  • The numerical calculation for solving boundary-value problem related to potential flows with a free surface is carried out by application of the localized finite element method. Only forced motion of 2-D body in infinitely deep fluid is considered, although this schemes is equally applicable to any first order time-harmonic problems of similar nature. The infinite domain of the fluid is separated into the inner flow field and the outer flow field with common inter-surface boundary. The finite element method is applied to obtain the solution in the inner flow field and the Green functions are utilized to represent the solution in the outer flow field. At the inter-surface boundary, the continuity of the value of potential and the normal derivative of the potential(i.e. matching condition) is conserved. The present method has better computational efficiency than the previous LFEM and the integral equation method of Frank. This enhanced computational efficiency is presumably due to the fact that the present method gives a symmetric coefficient matrix and requires less computational time in calculating the influence coefficient matrix of Green function than the integral equation method. And the irregular frequency desen't exist because the uniqueness of the solution is assured by the such that the exact free surface condition is satisfied on the boundary of the localized finite element region(i.e. inner region). As an example of the above method, the hydrodynamic forces for the circular cylinder and the rectangular cylinders are calculated. In the computed results, the small number of singularity distribution segments($3{\sim}6$) give good result relative to Ursell's and Vugts'.

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들뢰즈의 주름 사유와 바로크를 중심으로 본 바로크의 복식미 (The Aesthetic of Baroque Costume Focused on the Gilles Deleuze's 'Le Pli' and Baroque)

  • 성광숙
    • 복식
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    • 제65권8호
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    • pp.64-76
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    • 2015
  • Gilles Deleuze highly evaluated Baroque as the expression body that implements the fold theory, a philosophical thinking about the nature of beings. This can be seen as a meaning that Baroque implements the essence of the world, or the power constituting that essence. In addition, the beauty of Baroque focuses on 'New Harmony' the sum of partial forms caused by each element, and not Platonic harmony. he evaluated the aesthetic of Baroque costume as 'acquisition of liberation and autonomy', 'derived force from infinite spiritual forces'. This study analyzed the contents of the Aesthetic of Baroque costume based on the reviewed Deleuze's folding theory, Baroque aesthetics, and views of Baroque costume. As a result, it inferred the aesthetic of Baroque costume into four types, which are as follows: open structural openness, overlapping structural dynamics, integrated structural diversity, and relationship structural integrity. This study analyzed the aesthetic of Baroque costume based on Deleuze's philosophical thinking. The analysis showed that its aesthetics, which focused on "New Harmony", created energy of life and a venue for expression of power, as the aesthetics eliminated the prejudice of complexity and excessive decoration. In addition, Baroque costume is not the simple historical costume of the past. Instead, it is one of power and spirit, still existing in modern fashion. Baroque costume's formativeness and Paradigm can be said to provide the creative principle important for modern fashion because the aesthetics implemented in Baroque costume accepts free spirit, new challenge, difference and diversity, and is similar to the spirit pursued by modern art and fashion.

Hertz 접촉하중하에서의 복수표면균열의 상호간섭 (Mutual Interference of Two Surface Cracks under Hertzian Contact Loading)

  • 김상우;김석삼
    • 대한기계학회논문집A
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    • 제20권10호
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    • pp.3048-3057
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    • 1996
  • Analysis model containing two inclined surface cracks on semi-infinite elastic body is established and analyzed on the basis of linear fracture mechanics to examine mutual interference of two surface cracks. Muskhelishvili's complex stress functions are introduced and a set of singular integral equations is obtained for a dislocation density function. The stress intensity factors at crack tip are obtained by using the Gerasoulis'method. When two surface cracks are parallel and have the same length, the values of $K_1$and $\Delta K_11$(variation of $K_11$) for crack 1 and crack 2 decrease by the mutual interference of two surface cracks as the distance between the two surface cracks shortens. The effect of mutual interference is remarkable in high friction coefficient. In case that two surface cracks are parallel, the values of $K_1$and $\Delta K_11$for crack 2 decrease as the length ratio ot crack 2 to crack 1 becomes small. As the crack inclination angle rises, the value of $K_1$ and the mutual interference of $K_1$for crack 2 increase and the value of$\Delta K_11$ for crack 1 becomes smaller than that for crack 2.

2차원 초공동 유동의 중력과 자유표면 효과에 대한 수치해석 (A Numerical Analysis of Gravity and Free Surface Effects on a Two-Dimensional Supercavitating Flow)

  • 김형태;이현배
    • 대한조선학회논문집
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    • 제51권5호
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    • pp.435-449
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    • 2014
  • The effects of the gravity field and the free surface on the cavity shape and the drag are investigated through a numerical analysis for the steady supercavitating flow past a simple two-dimensional body underneath the free surface. The continuity and the RANS equations are numerically solved for an incompressible fluid using a $k-{\epsilon}$ turbulence model and a mixture fluid model has been applied for calculating the multiphase flow of air, water and vapor using the method of volume of fluid and the Schnerr-Sauer cavitation model. Numerical solutions have been obtained for the supercavitating flow about a two-dimensional $30^{\circ}$ wedge in wide range of depths of submergence and inflow velocities. The results are presented for the cavity shape, especially the length and the width, and the drag of the wedge in comparison with those of the case for the infinite fluid flow neglecting the gravity and the free surface. The influences of the gravity field and the free surface on the aforementioned quantities are discussed. The length and the width of the supercavity are reduced and the centerline of the cavity rises toward the free surface due to the effects of the gravity field and the free surface. The drag coefficient of the wedge, however, is about the same except for shallow depths of submergence. As the supercavitating wedge is approaching very close to the free surface, it is found the length and the width of a cavity are shorten even though the cavitation number is reduced. Also the present result suggests that, under the influence of the gravity field and the free surface, the length of the supercavity for a certain cavitation number varies and moreover is proportional to the inverse of the submergence depth Froude number.

망진(望診) 찰색(察色)에 있어서 비(鼻), 안(眼), 인당(印堂)의 중요성 (The importance of nose, eye, and In-dang(印堂) region in inspecting color diagnosis)

  • 장준용;강정수;김병수
    • 혜화의학회지
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    • 제19권1호
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    • pp.87-98
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    • 2010
  • There are four kinds of diagnosis methods in oriental medicine, and viewing diagnosis(望診) is the most important method among them. There are two ways in viewing diagnosis. These are viewing shape(觀形) and inspecting color(察色). Viewing shape diagnosis includes observation on geometric curve that is made by prominence of bones or lump of flesh, and examination on symmetric disparity and balance of vertical length among three vertical section of face. Inspecting color is literally inspecting several specified region of face. By Viewing shape, we can learn about characteristic physical mechanism of individuals, and basic disposition of reaction from inside and outside infinite stimulations. On the other hand, by inspecting color, we can estimate the very present pathologic and physiologic status of the patient. the estimation is based on principle that inside body changes reveal some reflections on facial skin surface. When you diagnosis patients with inspecting color method, It is important to distinguish color delicately, and to know where to see and what to know from it. The most important and frequently mentioned regions are myong-dang(明堂), eyes(眼) and In-dang(印堂). Myong-dang(明堂) indicates nose. In-dang(印堂) indicates the space between eyebrows. Unlike myong-dang(印堂) and eyes, In-dang(印堂) is occasionally treated as a trivial region then others. But, from research on classical books of facial examination and consideration of it's locational meanings, we've learned In-dang(印堂) is very important in viewing diagnosis, because this region is crossing of the other two regions and this fact means this region expresses the spiritual status as well as physical status in one region.