• 제목/요약/키워드: Frame Stress

검색결과 653건 처리시간 0.028초

고려인삼으로부터 Peroxidase 유전자의 Cloning 및 Activity

  • 손화;심주선;양덕춘
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 2004년도 추계 학술대회 및 정기총회
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    • pp.48-49
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    • 2004
  • A peroxidase[E.C.1.11.1.7] is very important enzymes,e.g., as preventive antioxidants. The function is connected with growth and specialization of plant. It makes from the peroxidase and other product to save itself When a plant have been under stress of environment. A class III peroxidase cDNA was isolated from the flower bud of Panax ginseng C.A. Meyer and named PgPrx3. The PgPrx3 is an ORF(open reading frame) of 1,065 bp and a amino acid of 355 residue. Used BioEdit software to compare the PgPrx3 amino acid sequence with other plants which have already known a result of Identity was Spinacia oleracea(70%), vigna angularis(71%), Nicotiana tabacum(69%) and Linum usitatissimym(65%). The peroxidase of Vigna angularis has high homology relationship with ginseng. for that reason, the PgPx3 is a member of class III peroxidase.

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X-ray PIV Measurements of Velocity Field of Blood Flows

  • Lee, Sang-Joon;Kim, Guk-Bae
    • International Journal of Vascular Biomedical Engineering
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    • 제4권1호
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    • pp.1-8
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    • 2006
  • The x-ray PIV method was improved for measuring quantitative velocity fields of real blood flows using a coherent synchrotron x-ray source. Without using any contrast media or seeding particles, this method can visualize flow pattern of blood by enhancing the phase-contrast and interference characteristics of blood cells based on a synchrotron x-ray imaging mechanism. The enhanced x-ray images were achieved by optimizing the sample-to-scintillator distance, the sample thickness, and hematocrit. The quantitative velocity fields of blood flows inside opaque tubes were obtained by applying a 2-frame PIV algorithm to the x-ray images of the blood flows. The measured velocity field data show typical features of blood flows such as the yield stress effect. The non-Newtonian flow characteristics of blood flows were analyzed using the x-ray PIV method and the experimental results were compared with hemodynamic models.

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역학적 구조에 대한 Knowledge-based 시스템을 이용한 파라메트릭 설계 (Parametric design for mechanical structure using knowledge-based system)

  • 이창호;김병인;정무영
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.1018-1023
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    • 1993
  • In mechanical structure design area, many FEM (Finite Element Method) packages are used. But the design using FEM packages depends on an iterative trial and error manner and general CAD systems cannot cope with the change of parameters. This paper presents a methodology for building a designing system of a mechanical structure. This system can generate the drawing for a designed structure automatically. It consists of three steps: generation of a structure by selection of the parameters, stress analysis, and generation of a drawing using CAD system. FEM module and parametric CAD module are developed for this system. Inference engine module generates the parameters with a rule base and a model base, and also evaluates the current structure. The parametric design module generates geometric shapes automatically with given dimension. Parametric design is implemented with the artificial intelligent technique. In older to the demonstrate the effectiveness of the developed system, a frame set of bicycle was designed. The system was implemented on an SUN workstation using C language under OpenWindows environment.

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화이버 요소를 이용한 3차원 강구조물의 개선소성힌지해석 (Refined-plastic hinge analysis of 3D steel structures using fiber elements)

  • 김승억;오정렬
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.281-287
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    • 2004
  • In this paper, the refined plastic-hinge analysis accounting for gradual yielding with fibers on a section is developed. Geometric nonlinearities of member(P-δ) and frame(P-Δ) are accounted for by using stability functions. Residual stresses are considered by assigning initial stresses to the fiber on the section. The elastic core in a section is investigated at every loading step to determine the axial and bending stiffness reduction. The strain reversal effect is captured by investigating the stress change of each fiber. The proposed analysis proves to be useful in applying for practical analysis and design of three-dimensional steel frames.

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압광 재료를 이용한 구조용 Y-TZP 소재의 고속 파괴현상 가시화 연구 (Visualization of High Speed fracture Behavior in Y-TZP by using Mechano-luminescence)

  • 김지식;손기선
    • 소성∙가공
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    • 제16권5호통권95호
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    • pp.348-353
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    • 2007
  • The propagation of a macro-scale crack and the accompanying transformation zone around it was visualized in an Y-TZP ceramic using a mechano-luminescence (ML) technique. The technique allows realistic fractures that take place catastrophically in actual applications to be realistically stimulated. Unlike conventional quasi-static R-curves, the ML technique on a relatively fast time frame permitted a so-called quasi-dynamic R-curve in the crack speed range from 50 to 140 m/sec. to be measured. Effective toughening then commenced and the applied stress intensity factor increased to 27 $MPa{\sqrt{m}}$. The transformation zone height obtained from the ML observations was in good agreement with that predicted by the Marshall model, and coincided with previously observed results for quasi-static conditions by Raman spectorscopy and x-ray analysis.

프리스트레스트 프리캐스트 콘크리트 패널을 이용한 잔교식부두의 최적설계 (A Study on Design Optimization of Mooring Pier using Prestressed Precast Concrete Panel)

  • 조병완;태기호;김용철
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.253-258
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    • 2000
  • Recently, the area of design optimization, especially structural optimization, has been and to be a continuous active area of research. And the design optimizations of port facilities have been achieved by many other civil engineers. But the design optimization of port facilities were limited to the design optimization of the breasting dolphin. This paper invested the design optimization of mooring pier and the foundations of mooring pier was suggested considering the convenience of repair and reinforcement work. The mooring pier devised with prestressed precast concrete panel and rigid frame welded wide flange beam to steel pipe pile. To accomplish the design optimization of mooring pier, the Augmented Lagrangian Multiplier Method(ALM) of ADS(Garret N. Vanderplaats) optimization routine, BFGS method as optimizer and Golden Section Method as one dimensional search were utilized. As a result, thirty percent of material cost for construction was reduced by design optimization. The tensile stress of concrete panel and bottom flage was critical constraints under service load. So, using high strength concrete and steel will be economical. And lots of initial values must be invested to accomplish the design optimization in design procedures.

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일반 모멘트 저항 철골조의 지진 응답 해석 (Earthquake Response Analysis of Ordinary Moment Resisting Steel Frames)

  • 윤명호
    • 한국디지털건축인테리어학회논문집
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    • 제4권1호
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    • pp.36-45
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    • 2004
  • Allowable stress design method have been most widely used in steel structure in Korea. Recently, not only high-rise buildings but also medium or low-rise buildings were designed as steel structure. Most of low-rise steel buildings are designed as ordinary moment resisting frames(MRF). But MRFs don't have any lateral force resisting devices such as bracing in braced frames. This study focuses mainly on nonlinear seismic response analyses of small scale steel frames which will be used later as specimens for the evaluation of MRF's seismic performances. The main parameters of analyses are arrangement of column axis, $P-{\Delta}$ effect, acceleration factor etc. The object of this paper is to estimate the seismic performances of MRFs, which are mostly designed in Korea, through the results of response analyses.

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원자로 부품의 수중 밀링 가공을 위한 4축 밀링 머신의 설계 (Design of 4-axes Milling Machine for Underwater Milling of Nuclear Reactor Parts)

  • 이동규;이기용;김성균;이근우;박진호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.351-354
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    • 2003
  • A new milling machine was designed and manufactured for underwater cutting of rotary specimen racks(RSR) used in the Korea Research Reactor. To cut out intermediate level radioactive stainless steel parts from RSR effectively and safely, the machine was designed to be operated in four directions of X, Y, Z axes and a rotation upon Z axis. The stress and displacement of main frame were simulated by using a structural analysis tool(Design Space) and the pressure of clamping device was evaluated.

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Behavior of symmetrically haunched non-prismatic members subjected to temperature changes

  • Yuksel, S. Bahadir
    • Structural Engineering and Mechanics
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    • 제31권3호
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    • pp.297-314
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    • 2009
  • When the temperature of a structure varies, there is a tendency to produce changes in the shape of the structure. The resulting actions may be of considerable importance in the analysis of the structures having non-prismatic members. Therefore, this study aimed to investigate the modeling, analysis and behavior of the non-prismatic members subjected to temperature changes with the aid of finite element modeling. The fixed-end moments and fixed-end forces of such members due to temperature changes were computed through a comprehensive parametric study. It was demonstrated that the conventional methods using frame elements can lead to significant errors, and the deviations can reach to unacceptable levels for these types of structures. The design formulas and the dimensionless design coefficients were proposed based on a comprehensive parametric study using two-dimensional plane-stress finite element models. The fixed-end actions of the non-prismatic members having parabolic and straight haunches due to temperature changes can be determined using the proposed approach without necessitating a detailed finite element model solution. Additionally, the robust results of the finite element analyses allowed examining the sources and magnitudes of the errors in the conventional analysis.

소성영역 진전효과를 고려한 공간 뼈대구조의 비탄성 해석 (Inelastic Analysis of Space Steel Frames Considering Spread of Plasticity)

  • 한재영;김성보
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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    • pp.45-52
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    • 2003
  • A finite element procedure to estimate ultimate strength of space frames considering spread of plasticity is presented. The improved displacement field is introduced based on inclusion of second order terms of finite rotations. All the nonlinear terms due to bending and torsional moment as well as axial force are precisely considered. The concept of plastic hinge is introduced and the incremental load/displacement method is applied for the elasto-plastic analysis. The initial yield surface is defined based on the residual stress and the full plastification surface is considered under the combined action of axial force, bending and torsional moments. The elasto-plastic stiffness matrices are derived using the flow rule and the normality condition of the limit function. Finite element solutions for ultimate strength of space frames are compared with available solutions and experimental results.

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