• Title/Summary/Keyword: analytic and numerical analysis

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Developing Technology Innovation Capability Evaluation Model for Small and Medium Enterprises (중소기업 육성을 위한 기술혁신역량 평가모형개발)

  • Cho, Joonggil;Lee, Sang-Sun;Byun, Min-Seok;Lee, Jonghwan;Kang, Kyungsu;Lee, Seongbin
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.1
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    • pp.162-169
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    • 2015
  • In this research, technology innovation capability evaluation model for small and medium enterprises was developed. To develop technology innovation capability evaluation model, two analytic technic was used. First one is AHP (Analytic Hierarchy Process) to give weight to each main index. Second one is fuzzy set theory to represent ambiguous index to numerical value. Finally, technology innovation capability evaluation model was achieved in combination with the same weight to AHP analysis and fuzzy set theory. With these results, small and medium enterprises can know important point in terms of strengthening the innovation capability evaluation.

Effects of Light Intensity on the Steady-State Fluorescence Quenching Kinetics

  • Mino Yang;Sangyoub Lee;Kook Joe Shin;Kwang Yul Choo;Duckhwan Lee
    • Bulletin of the Korean Chemical Society
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    • v.12 no.4
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    • pp.414-423
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    • 1991
  • Effects of light intensity on the steady-state fluorescence quenching kinetics are examined for general cases where the bimolecular quenching can occur via long-range energy transfer processes and the potential of mean force between the energy donor and acceptor molecules is not negligible. Approximate analytic expressions are derived for the steady-state quenching rate constant and for the ratio of the steady-state intensity of unquenched to quenched fluorescence. The analytic results are compared with the exact results obtained from numerical analysis and the results of conventional theories.

Numerical Tests of Large Mass Method for Stress Calculation of Euler-Bernoulli Beams Subjected to Support Accelerations (지지점 가속도에 의해 가진되는 보의 응력계산에 대한 거대질량법의 정확도)

  • Kim, Yong-Woo;Choi, Nam Seok;Jhung, Myung Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.188-193
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    • 2013
  • The large mass method for dynamic analysis of statically determinate beams subjected to in-phase support motions is justified by showing that the equation of motion of the beams under consideration is equivalent to that of large mass model of the beam when an appropriate large mass ratio is employed. The accuracy of the stress responses based on the beam large mass method is investigated through careful numerical tests. The numerical results are compared to analytic solutions and the comparison shows that the large mass method yields not only the time history of motion but also the distributions of bending moment and shear force accurately.

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Zero Cerenkov Radiation Angle Effect in Optical Parametric Amplification in the Cerenkov-idler Configuration (Cerenkov-idler configuration 광 매개증폭에서의 0° 체렌코프 복사각도 효과)

  • Suh, Zung-Shik
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.225-232
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    • 2014
  • Optical parametric amplification has been analyzed for the Cerenkov-idler configuration in planar waveguides. The coupled-mode theory is employed for the analysis. The coupled-mode equations are derived and the approximate analytic solution is obtained for no pump depletion. From the analytic solution, it is shown that the signal power gain can be enhanced as the Cerenkov radiation angle of the idler approaches to zero. The numerical example is also shown for the effect of the Cerenkov radiation angle approaching zero.

Computation of the Slow Viscous Flow about a Normal Plate (수직평판 주위를 흐르는 느린 점성류의 수치해석)

  • 인기문;최도형;김문언
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.9
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    • pp.2329-2338
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    • 1993
  • An accurate analysis procedure to solve the flow about a flat plate at various incidences has been developed. The Navier-Stokes equations of stream function and vorticity form are solved in a sufficiently large computational domain, in which the grid lines are mutually orthogonal. The details of the flow near the singularity at the tip of the plate is well captured by the analytic solution which is asymptotically matched to the numerically generated outer solution. The solution for each region is obtained iteratively : the solution of one (inner or outer) region uses that of the other as the boundary condition after each cycle. The resulting procedure is accurate everywhere and also computationally efficient as the singularity has been removed. It is applied to the flat plate for a wide range of Re : the results agree very well with the existing computation and experiment.

Development of Analytic Model for Estimation of the Carbonation Depth Considering the R.H. in the Concrete (콘크리트 내부 상대습도를 고려한 탄산화 깊이 산정 수치해석 모델 구축)

  • Park, Dong-Cheon;Cho, Gyu-Hwan;Ahn, Jae-Cheol;Kang, Byeung-Hee
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.71-72
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    • 2012
  • The purpose of this study is to evaluate the depth of carbonation considering the relative humidity in concrete using the FEM model. The difference of relative humidity in concrete has not been considered in calculating the carbonation depth in analytic model. That reason can make the over estimation in expectation of RC structure durability. The temperature and R.H. expectation model and the carbonation depth expectation model are development in past author's studies. The two models are coupled in this study. The fact that there is the difference between actual environment and acceleration test is revealed from FEM numerical analysis.

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Numerical Analysis of Viscous Flow on the Periodic Oscillating Flat Plate using Unsteady CFD Code (비정상 CFD 코드를 이용한 주기성 하모닉 진동 평판 위의 점성유동 수치해석)

  • Lee, Eunseok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.1000-1002
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    • 2017
  • Here, the unsteady Navier-Stokes solver has been developed using implicit dual time stepping method. The implicit dual time stepping method introduced the pseudo time step for solving the new residual including the steady state residual and real time derivative. For the validation of code, Stokes 2nd problem, the laminar flow on the oscillating flat plate was selected and compare the calculating results with analytic solutions. The calculating velocity profile and skin friction has a good agreement with analytic solutions.

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A New Sensitivity-Based Reliability Calculation Algorithm in the Optimal Design of Electromagnetic Devices

  • Ren, Ziyan;Zhang, Dianhai;Koh, Chang Seop
    • Journal of Electrical Engineering and Technology
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    • v.8 no.2
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    • pp.331-338
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    • 2013
  • A new reliability calculation method is proposed based on design sensitivity analysis by the finite element method for nonlinear performance constraints in the optimal design of electromagnetic devices. In the proposed method, the reliability of a given design is calculated by using the Monte Carlo simulation (MCS) method after approximating a constraint function to a linear one in the confidence interval with the help of its sensitivity information. The validity and numerical efficiency of the proposed sensitivity-assisted MCS method are investigated by comparing its numerical results with those obtained by using the conventional MCS method and the first-order reliability method for analytic functions and the TEAM Workshop Problem 22.

Computational Analysis of Three-Dimensional Turbulent Flow Around Magnetically Levitated Train Configurations in Elevated Track Proximity (고가궤도에 근접한 자기부상열차 형상 주위의 3차원 난류유동에 대한 수치해석)

  • Maeng, J.S.;Yang, S.Y.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.1
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    • pp.9-25
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    • 1994
  • In the present study, the Reynolds-averaged Navier-Stokes equations, together with the equations of the $k-{\varepsilon}$ model of turbulence, were solved numerically in a general body-fitted coordinate system for three-dimensional turbulent flows around the six basic shapes of the magnetically levitated train(MAGLEV). The numerical computations were conducted on the MAGLEV model configurations to provide information on shapes of this type very near the elevated track at a constant Reynolds number of $1.48{\times}10^{6}$ based on the body length. The coordinate system was generated by numerically solving a set of Poisson equations. The convective transport equations were discretized using the finite-analytic scheme which employed analytic solutions of the locally-linearized equations. A time marching algorithm was employed to enable future extensions to be made to handle unsteady and fully-elliptic problems. The pressure-velocity coupling was treated with the SIMPLER-algorithm. Of particular interests were wall effect by the elevated track on the aerodynamic forces and flow characteristics of the six models calculated. The results indicated that the half-circle configuration with extended sides and with smooth curvature of sides was desirable because of the low aerodynamic forces and pitching moment. And it was found that the separation bubble was occured at wake region in near the elevated track.

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Dynamic workspace analysis of a robot manipulator for conveyor tracking system (로봇의 동특성을 고려한 컨베이어 추적시스템의 작업영역 해석)

  • Park, Tae-Hyoung
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.2
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    • pp.226-234
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    • 1998
  • The concept of dynamic tracking line is proposed as the feasible tracking region for a robot in a robot-conveyor system, which takes the conveyor speed into consideration. This paper presents an effective method to identify the dynamic tracking line in a robotic workcell. The maximum line speed of a robot is derived in an analytic form using the parameterized dynamics and kinematics of the manipulator, and some of its properties are established mathematically. The identification problem of the dynamic tracking line is then formulated as a root-solving problem for a single-variable equation, and solved by using a simple numerical technique. Finally, numerical examples are presented to demonstrate the methodology and its applications in workspace specification.

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