• 제목/요약/키워드: geometric form

검색결과 547건 처리시간 0.022초

Geometrically non-linear static analysis of a simply supported beam made of hyperelastic material

  • Kocaturk, T.;Akbas, S.D.
    • Structural Engineering and Mechanics
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    • 제35권6호
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    • pp.677-697
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    • 2010
  • This paper focuses on geometrically non-linear static analysis of a simply supported beam made of hyperelastic material subjected to a non-follower transversal uniformly distributed load. As it is known, the line of action of follower forces is affected by the deformation of the elastic system on which they act and therefore such forces are non-conservative. The material of the beam is assumed as isotropic and hyperelastic. Two types of simply supported beams are considered which have the following boundary conditions: 1) There is a pin at left end and a roller at right end of the beam (pinned-rolled beam). 2) Both ends of the beam are supported by pins (pinned-pinned beam). In this study, finite element model of the beam is constructed by using total Lagrangian finite element model of two dimensional continuum for a twelve-node quadratic element. The considered highly non-linear problem is solved by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. In order to use the solution procedures of Newton-Raphson type, there is need to linearized equilibrium equations, which can be achieved through the linearization of the principle of virtual work in its continuum form. In the study, the effect of the large deflections and rotations on the displacements and the normal stress and the shear stress distributions through the thickness of the beam is investigated in detail. It is known that in the failure analysis, the most important quantities are the principal normal stresses and the maximum shear stress. Therefore these stresses are investigated in detail. The convergence studies are performed for various numbers of finite elements. The effects of the geometric non-linearity and pinned-pinned and pinned-rolled support conditions on the displacements and on the stresses are investigated. By using a twelve-node quadratic element, the free boundary conditions are satisfied and very good stress diagrams are obtained. Also, some of the results of the total Lagrangian finite element model of two dimensional continuum for a twelve-node quadratic element are compared with the results of SAP2000 packet program. Numerical results show that geometrical nonlinearity plays very important role in the static responses of the beam.

3차원 벡터 필드의 위상 공간 분석 (The Phase Space Analysis of 3D Vector Fields)

  • 정일홍;김용수
    • 디지털콘텐츠학회 논문지
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    • 제16권6호
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    • pp.909-916
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    • 2015
  • 본 논문에서는 위상 공간 분석을 통해 3D 벡터 필드를 표현하는 방법을 제안한다. 이 방법은 상미분 방정식과 벡터 필드 위상과의 연결에 기초를 두고 있다. 위상 공간 분석은 위상 공간 형태의 자율 방정식 시스템의 기하학적 보간법이 되어야 한다. 이 방정식 시스템의 모든 해는 공간에서의 곡선이 아니라 곡선을 따라가는 점의 움직임과 일치한다. 이러한 분석은 이 논문의 기반이다. 새로운 방법은 3차원 벡터필드에서 육면체 셀을 5 또는 6개의 사면체 셀로 분해하는 것을 요구한다. 임계점은 각 사면체의 간단한 선형 시스템을 풀어서 간단하게 구할 수 있다. 각 사면체의 일반해에 의해 그려지는 전체 곡선과 사면체의 한 면을 포함하는 평면과의 교차점을 계산함으로써 탄젠트 곡선은 구해진다.

인도네시아 또라자 전통주거의 역사적 특성과 현대적 양상에 관한 연구 (A Study on Historical Characteristics and Modern Trend of Torajan Traditional Housing in Indonesia)

  • 박순관
    • 한국주거학회논문집
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    • 제22권3호
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    • pp.59-71
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    • 2011
  • The purpose of this study is to investigate the basic historical characteristics and its modern trend of Torajan traditional housing architecture in Sulawesi Province, Indonesia. The Toraja culture belongs to the cosmological culture with Cosmos centric characteristics. A traditional house, being called 'tongkonan' in Toraja region, is more than just a structure, representing the symbol of family identity and tradition. The Torajan architecture is a combination of the myth and cosmos, also regional conditions. With a short description of the general conditions and spiritual values of the Toraja, this paper explains the space-composition, the stylistic characteristics, the ornamental elements, construction, and its modern trend, etc. In general, it is raised on stilts several metres high, with a dramatically boat-shaped roof. Village layout varies according to size. The houses are arranged in a row, side by side, with their front gables facing north. Each house stands opposite its own rice-barn. The houses with their oblong ground-plans, built on piles set on stones. The interior is divided into three or four rooms, having few window. The houses are embellished with carving and paintings, and the facades display engraved and painted geometric and figural designs. The most frequent motif is the buffalo head, ranging from the realistic to the highly stylized. The Torajan traditional housing have experienced radical changes during the Modern period. In spite of the popularity of new modern house-styles, the traditional architectural style is often now constructed as an icon of Toraja identity. This paper will be helpful for understanding regional diversity of the traditional housing in Southeast Asia.

폴드공간의 인지생태론적 특성과 그 효과 (The Cognitive Ecological Characteristics in Folded Space and Their Effects)

  • 김주미
    • 한국실내디자인학회논문집
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    • 제14권3호
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    • pp.181-190
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    • 2005
  • In accordance with the rapid growth of digital media in 1990s, the state of indetermination that is found in digital process has been emphasized in the field of natural science and philosophy. Digitalized space design has been dramatically developed and it raised heated debate and comment on 'folded space' The purpose of this thesis is to explore how the cognitive-ecological factors constitute fold structures in space design of the late 20th century. Syntax of space structure and geometric composition were analyzed to define what types of cognitive-ecological factors are contrived in the process of visual information. In particular, I put higher theoretical emphasis on what characteristics are ensued in the process of structuring spaces than any other subjects. Through theses analyses and discussions, I raised questions on what principles are operating to create new space design that counts on non-linear structure and its formational process. And I also observed what influences these structural principles of design could fundamentally bring to human beings. First, I proposed that we could overcome reductionist space design through cognitive-ecological approach. Some key concepts such as affordance, parallel processing, and redundancy were adopted as defining elements of non-linear structures. As a result of analyses, I found that the cognitive-ecological approach could substitute the reductionist space design of the past. What is also found is that the three variables are the ultimate ecological elements. In addition, as a methodological concept of fold structures, the form of 'topology' was highlighted because it could be a supporting idea to the cognitive-ecological factors. Second, I claimed that non-linear design is more experiential than rational linear design, and it is more efficiently correspondent to human being than any other forms. What is intended and implied in non-linear structure is also indicated.

내부튜브가 있는 골조 튜브 구조물의 전단응력에 대한 수치해석 (Numerical Analysis of Shear Stresses in Framed Tube Structures with Internal Tube(s))

  • 이강건;이리형
    • 한국전산구조공학회논문집
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    • 제15권3호
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    • pp.511-521
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    • 2002
  • 내부튜브를 가진 튜브 구조물의 보에 있는 전단응력을 평가하기 위하여 수치적인 해석기법이 제안되었다 이 기법은 휨과 전단변형을 고려한 튜브 보 개념 위에서 각각의 튜브를 연속 보로서 모델링 한다. 전단응력에 대한 수치해석은 패널에 작용하는 응력에 대한 탄성이론과 수학적인 유도를 기초로 하고 있다. 내부와 외부 튜브에 있는 변형곡선에 대한 표현식을 가정함으로써, 그 튜브에 있는 전단응력은 작용하중과 단면 2차 모멘트 그리고 구조물의 기하학적인 표현으로 구성된 선형 함수로서 표현된다 전단지체와 축 응력을 다룬 이전의 연구가 튜브내에 존재하는 전단응력을 수치적으로 해석하기 위하여 보완 발전되었다. 제안된 방법의 정확성과 유용성이 3개의 튜브 구조물의 해석을 통하여 증명 되었다

1930년대 의상 실루엣이 직물의 꽃문양 디자인에 미치는 영향 (Influence of 1930s Western Women's Apparel Silhouette on the Flower Textile Pattern)

  • 양아랑;이효진
    • 복식문화연구
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    • 제20권1호
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    • pp.49-61
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    • 2012
  • This study focuses on looking at the influence of silhouette in the 1930s on fabric pattern design by comprehending how differently flower-pattern design were found according to clothing silhouette. The period scope of research was limited to 1930s, and the research object was set as the flower patterns seen in the designer's high-fashion and the women's daily apparel as well as the clothes for sports and leisure activities. Based on the above research scope, the researcher investigated the clothing silhouette and the textile patterns in 1930s by reviewing the literature about domestic and foreign books, research papers, domestic and foreign fashion magazines, information on the Internet. A glance at the women's clothing in the 1930s reveals that they emphasized something inactive, elegant, feminine and that great popularity was given to feminine silhouette that closely fitted the body and long and slim, as skirts became longer and longer. Like this, silhouette refused traditional methods in the technique of expressing flower patterns that were on-trend in that period, pursued the freedom of line and form, used shadowing technique by means of free pens and brushes and the effect of watercolors. It also arranged in a semitransparent way and painted contours alone, too. Flower patterns fell into two categories: amorphous abstract patterns and standardized abstract patterns. The patterns expressed themselves, divided into small-scale irregular patterns and abstract geometric patterns that filled the entire textile.

바로크(Baroque) 양식 시대 서양 남성복에 나타난 남성의 몸 이미지 (Male Body Image Appearing on the Western Men's Costume in the Baroque Era)

  • 이효진
    • 복식문화연구
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    • 제19권4호
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    • pp.723-739
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    • 2011
  • This research seeks to analyze western men's costume in the Baroque era in relation to men's physical beauty from its most detailed and interesting perspective to fomulate a plausible reasoning related to the aesthetic sense of body as expressed in men's costume. This research used national and international books, theses and internet data upon which to base a literature review for a correct understanding of Baroque style and at the same time empirical research to analyze the body image expressed in men's costume. The Baroque style expressed in the 17th century costume offered a dynamic feeling through wavy curves, and its brilliant and colorful decorations created a passionate and charming mood resembling a flame. Accordingly, this research studied the body image as it appeared in the form of 17th century western men's costume by dividing it into the contact beauty of the human body and the manner of hiding the architectural beauty of the human body. First, the exposed silhouette by clothing coming into contact with the human body could be found mainly in upper-class men's costume in the first half of the 17th century. The shorter and tighter doublets and knee breeches could be analyzed in terms of erotic imagery that emphasized masculinity, aristocratic imagery that stressed a distinctive status, and geometric imagery that expressed a triangular pattern. Second, the constructive expression by hiding the human body could be found in upper-class men's costume starting in the mid-17 century. The wearing of the justaucorps could be studied in terms of how it came into contact with the beauty of the human body but also how this clothing style the hid the architectural beauty of human body.

기하학적 불변벡터기반 랜드마크 인식방법 (Landmark Recognition Method based on Geometric Invariant Vectors)

  • 차정희
    • 한국컴퓨터정보학회논문지
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    • 제10권3호
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    • pp.173-182
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    • 2005
  • 본 논문에서는 항해 시 위치인식에 사용하기 위하여 카메라의 뷰포인트에 무관한 랜드마크를 인식하는 방법을 제안한다. 기존연구에서 사용된 특징들은 카메라의 뷰포인트에 따라 변하고 이에따른 정보 양의 증가로 위치확인을 위한 시각적인 랜드마크의 추출이 어렵다. 본 논문에서 제안된 방법은 특징 추출단계, 학습과 인식단계, 정합단계의 삼단계로 구성된다. 특징 추출단계에서는 영상의 관심영역을 설정, 이 영역 안에서 코너점을 추출하는데, 추출 시 작은 고유값의 통계적 분석을 통해 보다 정확하고 잡음에 강한 특징을 추출하는 방법을 제안한다. 학습 및 인식단계에서는 5개의 특징점으로 구성된 특징모델이 뷰포인트에 무관한 특징점인지를 검사하여 강건 특징모델을 구성한다. 정합단계에서는 시간 복잡도를 줄이고 정확한 대응점을 산출하기 위하여 유사도 평가함수와 Graham 탐색방법을 이용한 정합 방법을 제안한다. 실험에서는 다양한 실내영상을 가지고 제안한 방법과 기존방법을 비교 분석함으로써 제안한 방법의 우수함을 보였다.

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스마트폰 사용자를 위한 발광 스마트 백 개발 (A Study on the Development of Luminous Smart Bag for Smartphone Users)

  • 박진희;김주용
    • 패션비즈니스
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    • 제24권1호
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    • pp.15-28
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    • 2020
  • The purpose of this study was to develop and propose creative smart bags in emotional e-textiles using LEDs that inform smartphone users of motion-induced luminescence and ringing of cell phones. The LED light-emitting operation tasks produced in the study were applied to each of the three design smart bags, setting the five cases of luminance by a call initiated, absent phone, rejecting answering phone, texting, and motion-induced luminescence. In the male laptop bags of LED luminous images using wappen, 10 LEDs could be separated by a total of three pins to display the luminous mode, and all 10 LEDs became a total of five luminous patterns, including all that illuminate and those that illuminate randomly. E-wappen rendered the motif a strong sense of visibility and performed six roles on phone rings and texting. To develop a women's tote bag, we did a laser cut and attached the leather strips and placed 10 triangular LEDs to form a geometric LED e-textile. It provides the possibility of transforming simple design from traditional fashion into a more interesting and various smart designs. An entertainment smart bag using graphic design was constructed by applying a tilt sensor to look like a light in the night sky by shaking and moving the bag. The graphic design and composition of LEDs indicate that LEDs and fashion item are applied in harmony rather than heterogeneous, enabling them to be applied as fashion-oriented wearable smart products.

GPU를 이용한 대량 삼각형 교차 알고리즘 (Robust GPU-based intersection algorithm for a large triangle set)

  • 경민호;곽종근;최정주
    • 한국컴퓨터그래픽스학회논문지
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    • 제17권3호
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    • pp.9-19
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    • 2011
  • 삼각형간의 교차 계산은 많은 3 차원 기하 문제들을 해결하는데 있어서 기본적으로 요구되는 연산 과정이다. 본 논문에서는 대량의 삼각형 집합 안에서의 교차 계산을 효율적이며 강인하게 처리할 수 있는 GPU 알고리즘을 제안한다. 이 알고리즘은 k-d 트리의 구성, 삼각형쌍 생성, 정확한 교차 계산을 모두 GPU에서 처리한다. 여기서 사용되는 k-d 트리에서는 분할 과정 중에 삼각형들의 복사가 많이 발생한다. 이렇게 복사된 삼각형들로 인하여 중복된 삼각형쌍들이 많이 생성되는데, 이러한 중복 삼각형쌍들을 효율적으로 제거하기 위하여 분할 인덱스를 도입하였다. 분할 인덱스는 간단한 논리곱 연산만으로 중복 여부를 효과적으로 판단할 수 있다. 수치적 강인성을 높이기 위하여는 부동소숫점 필터링을 통해 불안전한 삼각형쌍들을 분리하고, CLP(controlled linear perturbation)를 이용하여 CPU쓰레드에서 처리하도록 하였다. 제안한 알고리즘은 기존의 민코스키합 알고리즘의 합삼각형 교차계산에 적용하여 효율성과 강인성을 입증하였다.