• 제목/요약/키워드: Computational Techniques

검색결과 1,311건 처리시간 0.021초

Turing, Turing 불안정성 그리고 수리생물학과 연소 (Turing, Turing Instability, Computational Biology and Combustion)

  • 김종수
    • 한국연소학회지
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    • 제8권1호
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    • pp.46-56
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    • 2003
  • The present paper is concerned with the development of the computational biology in the past half century and its relationship with combustion. The modem computational biology is considered to be initiated by the work of Alan Turing on the morphogenesis in 1952. This paper first touches the life and scientific achievement of Alan Turing and his theory on the morphogenesis based on the reactive-diffusive instability, called the Turing instability. The theory of Turing instability was later extended to the nonlinear realm of the reactive-diffusive systems, which is discussed in the framework of the excitable media by using the Oregonator model. Then, combustion analogies of the Turing instability and excitable media are discussed for the cellular instability, pattern forming combustion phenomena and flame edge. Finally, the recent efforts on numerical simulations of biological systems, employing the detailed bio-chemical knietic mechanism is discussed along with the possibility of applying the numerical combustion techniques to the computational cell biology.

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Parabolic 방정식의 효율적인 시간해석 알고리즘에 대한 비교연구 (A Comparative Study of Efficient Transient Analysis Algorithm for Parabolic Equations)

  • 최창근;이은진;유원진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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    • pp.68-74
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    • 1998
  • A finite element analysis for physical phenomenon which are governed by parabolic equation, has some inefficiencies caused by much computational time and large storage space. In this paper, a comparative study is performed to suggest the best efficient transient analysis algorithms for parabolic equations. First, the general finite element analysis techniques are summarized in views of formulation procedures, treatments of convection terms. and time stepping methods. Results of several combinations applied to one dimensional convection-diffusion equation and Burger equation are represented and compared using some criteria such as accuracy, stability, and computational time. Through the results, some guidelines to select a algorithm for solving parabolic equations are proposed for diffusion dominant and convection dominant cases. Finally applicability of two dimensional extension of the result is also discussed.

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Complex Conjugate Resolved Retinal Imaging by One-micrometer Spectral Domain Optical Coherence Tomography Using an Electro-optical Phase Modulator

  • Fabritius, Tapio E.J.;Makita, Shuichi;Yamanari, Masahiro;Myllyla, Risto A.;Yasuno, Yoshiaki
    • Journal of the Optical Society of Korea
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    • 제15권2호
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    • pp.111-117
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    • 2011
  • Full-range spectral domain optical coherence tomography (SD-OCT) with a 1-${\mu}m$ band light source is shown here. The phase of the reference beam is continuously stepped while the probing beam scans the sample laterally (B-scan). The two dimensional spectral interferogram obtained is processed by a Fourier transform method to obtain a complex spectrum leading to a full-range OCT image. A detailed mathematical explanation of the complex conjugate resolving method utilized is provided. The system's measurement speed was 7.96 kHz, the measured axial resolution was $9.6{\mu}m$ in air and the maximum sensitivity 99.4 dB. To demonstrate the effect of mirror image elimination, In vivo human eye pathology was measured.

Computational evaluation of wind loads on buildings: a review

  • Dagnew, Agerneh K.;Bitsuamlak, Girma T.
    • Wind and Structures
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    • 제16권6호
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    • pp.629-660
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    • 2013
  • This paper reviews the current state-of-the-art in the numerical evaluation of wind loads on buildings. Important aspects of numerical modeling including (i) turbulence modeling, (ii) inflow boundary conditions, (iii) ground surface roughness, (iv) near wall treatments, and (vi) quantification of wind loads using the techniques of computational fluid dynamics (CFD) are summarized. Relative advantages of Large Eddy Simulation (LES) over Reynolds Averaged Navier-Stokes (RANS) and hybrid RANS-LES over LES are discussed based on physical realism and ease of application for wind load evaluation. Overall LES based simulations seem suitable for wind load evaluation. A need for computational wind load validations in comparison with experimental or field data is emphasized. A comparative study among numerical and experimental wind load evaluation on buildings demonstrated generally good agreements on the mean values, but more work is imperative for accurate peak design wind load evaluations. Particularly more research is needed on transient inlet boundaries and near wall modeling related issues.

학교교실의 적재하중에 관한 연구 (A Study on Live Loads in School)

  • 서극수;박성수
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1994년도 가을 학술발표회 논문집
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    • pp.61-69
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    • 1994
  • The most fundamental elements in analyzing the structure of building are strength of maerials and value of loads. The applied loads of structural analysis in our country are classified into the dead and live loads. This study, with special reference to live load, is to suggest the stochastic character of live load and the appropriate live load by using the Monte-carlo Simulation method, one of the O. R(Operations Research) techniques acting on school buildings.

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구조물의 동특성 추정방법에 관한 연구 (Identification of Structural Dynamic Systems)

  • 윤정방
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1989년도 봄 학술발표회 논문집
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    • pp.66-70
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    • 1989
  • Methods for identification of modal properties of linear structures are presented. The extended Kalman filtering technique is empolyed. The state equation is formulated by two different ways, namely by the time domain and frequency domain approaches. Verifications are carried out by using simulated records of ground acceleration and structural response. Then the techniques are applied to the estimation of modal parameters of a scaled model for a 3-story building which is installed on a shaking table.

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철골 구조물의 통합 설계 시스템 (Integrating drafting with analysis and design of framed steel structures)

  • 김홍국;이병해
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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    • pp.127-132
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    • 1991
  • The purpose of this study is to integrate a structural design Process of framed steel structures. It is composed of analysis, design, drafting and construction management. However each step of these works involved with a large amount of data and man hour resources. The aim of this study is to alleviate time consuming efforts mentioned above by integrating the different stage of works. Very successful results have been achieved by setting up a common database in whole process and applying the techniques of knowledge base system.

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사장교의 동특성분석에 관한 실험적 연구 (Experimental Study on Dynamic Characteristics of Cable-Stayed Bridge)

  • 황학주;김상효;전귀현;박기태;신주환
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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    • pp.209-216
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    • 1994
  • Recently, cable-supported long-span bridge are widely constructed due to improved quality of cable and development of design and construction techniques. In this study, an existing cable-stayed bridge, Dolsan Bridge, has been evaluated based on the cable forces measured using vibration method. And the finite element model using in this study for the dynamic analysis has been found to be quite comparable with dynamic mode shapes and natural frequencies estimated from experimental data induced by ambient traffic excitations.

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부재응력분포계수와 부재간 응력 상관성 (Response Force Distribution Factors of Members and Mutuality of Response Forces between Members)

  • 김치경;이시은;홍건호
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.363-370
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    • 2004
  • This Paper presents the response force distribution factor(RDF) and its application to recalculation of member forces in case of partial changes of structures. Using RDF, the mutuality of response forces between members can be estimated. The reanalysis technique recalculates directly any displacement or member force under consideration in real time without a full reanalysis in spite of local changes in member stiffness or connectivity using RDF. It is expected that RDF and the reanalysis technique can be used to develop efficient analysis techniques for tall buildings.

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철도터널 화재시 승객 생존율 예측을 위한 확률론적 평가코드 개발연구 (Development of Probabilistic Fatality Estimation Code for Railway Tunnel Fire Accidents)

  • 곽상록
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.445-450
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    • 2004
  • Tunnel fire accident is one of the critical railway accidents, together with collision and derailment. For the safe operation many tunnel design guidelines are proposed but many Korean railway tunnels do not satisfy these guidelines. For the safety improvement, current safety level is estimated in this study. But so many uncertainties in major input parameters make the safety estimation difficult. In this study, probabilistic techniques are applied for the consideration of uncertainties in major input parameters. As results of this study, probabilistic safety estimation code is developed.

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