• 제목/요약/키워드: form-finding

검색결과 603건 처리시간 0.04초

가황 고무의 변형 에너지 함수를 통한 재료 특성화 방법에 관한 연구 (A Study on the Characterization of Gum Vulcanizates by Strain Energy Function of Hyperelastic Material)

  • 박현철;윤성기
    • 대한기계학회논문집
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    • 제16권7호
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    • pp.1341-1350
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    • 1992
  • 본 연구에서는 시험 재료의 특성을 가장 잘 나타낼 수 있으며 시험 자료밖의 범위에서도 물리적 타당성을 갖는 변형 에너지 함수를 찾기 위한 방법의 일환으로 기 존의 여러 방법들을 이용하여 동일한 시험 자료에 적용함으로써, Rivlin 형태와 Ogden 형태에 대한 재 조사를 실시하였다. 그리고 비선형 대변형 재료의 실제 사용 예로서 앞에서 언급한 타이어용 고무를 들 수 있는데 이들에 대한 변형 에너지 함수를 결정하 기 위한 시험자료는 실제적 문제때문에 단순 인장과 같은 비교적 간단한 경우에 대하 여 한정되어 있으므로, 이러한 자료로부터 여러 종류의 하중 상태를 예측할 수 있는 변형 에너지 함수를 찾고자 하였다.

Downlink Performance of Distributed Antenna Systems in MIMO Composite Fading Channel

  • Xu, Weiye;Wang, Qingyun;Wang, Ying;Wu, Binbin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권10호
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    • pp.3342-3360
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    • 2014
  • In this paper, the capacity and BER performance of downlink distributed antenna systems (DAS) with transmit antenna selection and multiple receive antennas are investigated in MIMO composite channel, where path loss, Rayleigh fading and lognormal shadowing are all considered. Based on the performance analysis, using the probability density function (PDF) of the effective SNR and numerical integrations, tightly-approximate closed-form expressions of ergodic capacity and average BER of DAS are derived, respectively. These expressions have more accuracy than the existing expressions, and can match the simulation well. Besides, the outage capacity of DAS is also analyzed, and a tightly-approximate closed-form expression of outage capacity probability is derived. Moreover, a practical iterative algorithm based on Newton's method for finding the outage capacity is proposed. To avoid iterative calculation, another approximate closed-form outage capacity is also derived by utilizing the Gaussian distribution approximation. With these theoretical expressions, the downlink capacity and BER performance of DAS can be effectively evaluated. Simulation results show that the theoretical analysis is valid, and consistent with the corresponding simulation.

건축과 언어: 1960년대 이후 서구건축의 이론과 실험 (Architecture and Language: Theories and Practice in Architecture since the 1960s.)

  • 김성홍
    • 인문언어
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    • 제1권2호
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    • pp.107-121
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    • 2001
  • This paper examines the way in which the idea of language has been introduced in architectural discourse since the late 1960s. The paper reviews the works of Robert Venturi, Charles Jencks, Peter Eisenman, Alan Colquhoun, and Mario Gandelsonas, which explore the analogy between linguistic and architectural form. All of the writers above are responsive to each other's theoretical positions, sometimes implicitly and sometimes explicitly. A system of signs can be approached by asking how the lexicon and syntax are proportioned. The same question may be posed to architecture: can architecture be understood as a lexicon or as a relational structure, such as language is\ulcorner Two perspectives are presented by architectural theorists. The first advocated by Venturi and Jencks posit architectural form as a problem of signs. The problem with this perspective is that, it reduces architecture into popularized iconography in favor of the representational aspects of architectural form. The second perspective, developed by Eisenman, explores the possibility of finding new formal constructs in the abstract relationship of formal properties. Eisenman's theory, however, has its own problems for, in highlighting syntactic structure, it minimizes the distinction between the perceptual and the pragmatic dimensions. Yet both perspectives address crucial problems of contemporary architecture and expand architectural discourse into the broader realm of humanistic studies.

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하멜을 이용한 모바일 디지털 스토리텔링 (Mobile digital storytelling using Hamel)

  • 고석하;임지훈;김성백;문혜경;현정석
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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    • pp.172-175
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    • 2006
  • "하멜"은 제주와 조선을 유럽에 최초로 알린 인물이라는 학술적 가치를 가지고 있지만, 도서를 제외한 디지털 콘텐츠의 개발은 전무한 상태이다. 본 논문에서는 이러한 "하멜" 캐릭터를 이용하고 제주의 문화를 소재로 하여, PDA의 장점인 휴대성, 멀티미디어 이용 등을 바탕으로 한 교육용 게임 콘텐츠를 제작하였다. 원시적인 점수 쌓기 게임 형식에서 탈피하여 게임 공간과 "하멜" 캐릭터의 인터렉션에 따른 다양한 시나리오를 가지는 형태로, 지역문화와 사이버 공간을 접목시키는 디지털 스토리텔링의 구조를 띈다. 게임을 통해 학습을 하는 방법에 있어 제주 특유의 문화 콘텐츠를 활용한 퀴즈, 십자 퍼즐, 순서 맞추기, 틀린 그림 맞추기, 조각 퍼즐 등의 게임을 이용하였다. 이러한 콘텐츠들은 각기 모듈화된 설계를 통해 각각의 모듈이 독립적 역할을 수행하여 약간의 조정만으로도 제주 외의 다른 지역의 콘텐츠를 이용하여 시리즈 형식의 무한한 게임 콘텐츠 제작이 가능하도록 설계하였다.

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Fluid-structure interaction of a tensile fabric structure subjected to different wind speeds

  • Valdes-Vazquez, Jesus G.;Garcia-Soto, Adrian D.;Hernandez-Martinez, Alejandro;Nava, Jose L.
    • Wind and Structures
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    • 제31권6호
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    • pp.533-548
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    • 2020
  • Despite the current technologic developments, failures in existent tensile fabric structures (TFS) subjected to wind do happen. However, design pressure coefficients are only obtained for large projects. Moreover, studies on TFSs with realistic supporting frames, comparing static and dynamic analyses and discussing the design implications, are lacking. In this study, fluid-Structure analyses of a TFS supported by masts and inclined cables, by subjecting it to different wind speeds, are carried out, to gain more understanding in the above-referred aspects. Wind-induced stresses in the fabric and axial forces in masts and cables are assessed for a hypar by using computational fluid dynamics. Comparisons are carried out versus an equivalent static analysis and also versus loadings deemed representative for design. The procedure includes the so-called form-finding, a finite element formulation for the TFS and the fluid formulation. The selected structure is deemed realistic, since the supporting frame is included and the shape and geometry of the TFS are not uncommon. It is found that by carrying out an equivalent static analysis with the determined pressure coefficients, differences of up to 24% for stresses in the fabric, 5.4% for the compressive force in the masts and 21% for the tensile force in the cables are found with respect to results of the dynamic analysis. If wind loads commonly considered for design are used, significant differences are also found, specially for the reactions at the supporting frame. The results in this study can be used as an aid by designers and researchers.

Analytical study on cable shape and its lateral and vertical sags for earth-anchored suspension bridges with spatial cables

  • Gen-min Tian;Wen-ming Zhang;Jia-qi Chang;Zhao Liu
    • Structural Engineering and Mechanics
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    • 제87권3호
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    • pp.255-272
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    • 2023
  • Spatial cable systems can provide more transverse stiffness and torsional stiffness without sacrificing the vertical bearing capacity compared with conventional vertical cable systems, which is quite lucrative for long-span earth-anchored suspension bridges' development. Higher economy highlights the importance of refined form-finding analysis. Meanwhile, the internal connection between the lateral and vertical sags has not yet been specified. Given this, an analytic algorithm of form-finding for the earth-anchored suspension bridge with spatial cables is proposed in this paper. Through the geometric compatibility condition and mechanical equilibrium condition, the expressions for cable segment, the recurrence relationship between catenary parameters and control equations of spatial cable are established. Additionally, the nonlinear general reduced gradient method is introduced into fast and high-precision numerical analysis. Furthermore, the analytic expression of the lateral and vertical sags is deduced and discussed. This is very significant for the space design above the bridge deck and the optimization of the sag-to-span ratio in the preliminary design stage of the bridge. Finally, the proposed method is verified with the aid of two examples, one being an operational self-anchored suspension bridge (with spatial cables and a 260 m main span), and the other being an earth-anchored suspension bridge under design (with spatial cables and a 500 m main span). The necessity of an iterative calculation for hanger tensions on earth-anchored suspension bridges is confirmed. It is further concluded that the main cable and their connected hangers are in very close inclined planes.

의상 전문잡지를 통해 본 해체적 의상디자인 (A Study on Deconstructional Fashion Design Through Fashion Magazine)

  • 이순자;권미정;김주현
    • 한국의류산업학회지
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    • 제1권4호
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    • pp.349-357
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    • 1999
  • The purpose of this study was to examine how deconstruction, which currently had a great deal of influence on fashion, was actually accepted in view of fashion form or material. In order to track the tendency of deconstructional fashion, an attempt to find out what deconstructional methods were used in fashion design for each formative element was made by looking into earlier studies. Then an analysis was made over the recent fashion magazines. As a result of analyzing four fashion magazines, the most distinctive feature was found to be the use of seethrough cloth. In addition, unsymmetrical form also was immensely used. The next most frequently appeared form was layering, followed by slash or making a hole, lingerie look, padded cloth, indeterminate form, wrinkled cloth and patchworked cloth in the order named. The dominant layering style, the most widely used deconstructional fashion, was that inner cloth could be seen through outer seethrough cloth. The most frequently employed deconstructional cloth was seethrough cloth. Rather than complete seethrough cloth, the shape of lace, net or pattern was employed largely, in which the body could be partially hidden. The most largely used deconstructional method was a slash or making a hole. Most slashes appeared on the front part of the body, to which seethrough stuff was attached in many cases. Based on the above mentional finding. 10 kinds of deconstructional design were proposed for each method.

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정적 단일 배정 형태를 위한 정적 타입 배정에 관한 연구 (A Study on Static Type Assignment for Static Single Assignment Form)

  • 김기태;유원희
    • 한국콘텐츠학회논문지
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    • 제6권2호
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    • pp.117-126
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    • 2006
  • 자바 바이트코드는 많은 장점을 갖지만 수행 속도가 느리고 분석이 어렵다는 단점을 갖는다 이를 극복하기 위해 바이트코드에 대한 분석과 최적화가 수행되어야 한다. 우선 바이트코드에 대한 제어 흐름 분석을 수행한다. 제어 흐름 분석 후 데이터 흐름 분석과 최적화를 위해서 변수가 어디서 정의되고 어디서 사용되는지에 대한 정보가 필요하다. 각 위치에서 변수에 배정되는 값에 따라 동일한 이름의 변수가 다른 위치에서 다른 값을 가지는 경우가 발생한다. 따라서 정적으로 값과 타입을 결정하기 위해서 변수는 배정되는 것에 따라 분리되어야 한다. 이를 위해 단일 배정 형태를 이용하여 표현할 수 있다. 정적 단일 배정형태(SSA Form)로 변경한 후 정적 분석과 최적화를 위해서는 각 변수와 표현식이 나타내는 각각의 노드에 타입 정보를 설정해야 한다. 본 논문은 타입에 대한 기본 정보를 바탕으로 관련된 동등한 노드를 발견하고 강 결합 요소로 설정한 후 각 노드에 타입을 효율적으로 설정하는 방법을 제안한다

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가상환경의 미디어 형식에 대한 사용자 평가 연구 (A Study on the User Evaluation for Media Form of Virtual Environment)

  • 박수빈;윤소연
    • 한국실내디자인학회논문집
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    • 제17권5호
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    • pp.166-174
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    • 2008
  • As the use of virtual environment for decision-making interior or architectural design has been increasingly broaden, the choice of media form-physical, objective properties of a display medium-became and important issue to take into consideration. This research deals with the effects and differences between two types of media for a virtual environment; wall projection screen(120") and PC monitor(17"). In addition, efficient adoption of the two media forms was also proposed in this research. A total of 90 subjects participated in pre-designed three experimental groups(A group: experiment with a wall projection screen, B group: experiment with PC monitor, C group: both) and answer the seating preferences, the presence inventory, and the decision confidence using a simulated virtual restaurant environment. The results are as follows: (1) seating preferences for the tables located in frequent traffic area and near other spaces such as restroom and th kitchen are significantly different by the media form. While there is no significant difference found in seating preferences for most tables except high traffic areas near entrances between the two media. This result demonstrates the effects of media type or screen size on user perception for the areas near structural or interior design elements. (2) The presence measure in this research consist of in this research consist of four factors: 'spatial presence,' 'object presence,' 'positive effects,' and 'the factor of negative effects. 'The mean values of the items involving engagement or interaction in the spatial presence factor and the object presence factor are significantly different by the media form. A higher sense of presence of presence was observed in the wall projection screen. (3) PC monitor condition was shown to provide a higher level of decision confidence. Based on the research finding, conclusions and implications are discussed.

3차원 가상모형을 이용한 하악 제2소구치 교두 변이 대칭성에 대한 융복합적 분석 - 전북지역 일부 대학생을 중심으로 (Convergence analysis of cusp variation symmetry of the mandibular second premolars using 3-dimensional virtual models - Focusing on college students in Jeollabuk-do)

  • 남신은
    • 디지털융복합연구
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    • 제20권2호
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    • pp.317-323
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    • 2022
  • 본 연구는 3차원 가상모형을 이용하여 하악 제2소구치 교두 변이 양상을 정성적으로 분석하고, 교두 변이에 따른 치아 표면적의 정량적 분석과 함께 좌·우측 대칭성을 분석하고자 하였다. 127개의 하악 제2소구치 가상치아를 준비한 후, RapidForm2004(INUS technology INC, Seoul, Korea)을 이용하여 각 교두의 절대적/상대적 단면적, 전체 치관 단면적, 교합면의 중심구 형태 등을 분석하였다. 통계방법은 Independent t-test, Kruskal-Wallis test 및 교차분석을 시행하였다. 연구 결과, 중심구의 형태는 양측간 높은 대칭성을 보였다. 좌측에서 U 형태이면 우측도 100.0% U 형태를 나타냈으며, 나머지 H 형태와 Y 형태는 각각 73.7%, 78.9% 비율로 양측간 동일한 중심구 형태를 나타냈다(p<.001). 본 연구에서 얻은 결과는 CAM/CAM을 이용한 보철물 제작 시 참고자료로 활용이 가능할 것이며, 향후 맹출 직후의 하악 제2소구치를 포함한 더 많은 샘플을 대상으로 한 후속연구가 이루어지기를 기대한다.