• Title, Summary, Keyword: Optimization procedure

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A Study on the Development of Optimization Procedure for Radiological Protection (방사선 방어의 최적화 절차론 개발에 관한 연구)

  • Song, Jong-Soon
    • Journal of Radiation Protection and Research
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    • v.19 no.1
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    • pp.1-11
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    • 1994
  • Considering the variety of application and other factors in performing the optimization of radiological protection, it is necessary to use well-structured optimization procedure. In this study, an optimization procedure for design stage of nuclear power plant was proposed, and applied in the selection of alternatives for reducing occupational radiation exposure. As an aiding technique for decision-making, multi-criteria technique was used. As a result, priorities of alternatives are determined, and a problem of applying this result to real situation is reviewed. The developed procedure for optimization can be extended to other areas such as radioactive waste management, medical use of radiation, etc.

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Topology Decision of Truss Structures by Advanced Evolutionary Structural Optimization Method (개선된 진화론적 구조최적화에 의한 트러스 구조물의 형태결정)

  • Jeong, Se-Hyung;Pyeon, Hae-Wan
    • Journal of the Korean Association for Spatial Structures
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    • v.3 no.3
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    • pp.67-74
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    • 2003
  • The purpose of this study is to improve convergence speed of topology optimization procedure using the existing ESO method and to deal with topology decision of the truss structures according to a boundary condition, such as cantilever type. At the existing ESO topology optimization procedure for the truss structures, the adjustment of member sizes according to target stress has been executed by increasing or reducing a very small value from each member size. In this case, it takes too much iteration till convergence. Accordingly, it is practically hard to obtain optimum topology for a large scale structures. For that reason, it is necessary to improve convergence speed of ESO method more effectively. During the topology decision procedure, member sizes are adjusted by calculating approximate solution for member sizes corresponding to the target stress at every step, the new member sizes are adjusted by such method are applied in FEA procedure of next step.

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Structural design using topology and shape optimization

  • Lee, Eun-Hyung;Park, Jaegyun
    • Structural Engineering and Mechanics
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    • v.38 no.4
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    • pp.517-527
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    • 2011
  • A topology optimization and shape optimization method are widely used in the design area of engineering field. In this paper, a unified procedure to combine both topology and shape optimization method is used. A material distribution method is used first to extract necessary design parameters of the structure and a shape optimization scheme using genetic algorithm and satisfying all the condition follows. As an example, a GFRP bridge deck is designed and compared with other commercial products. The performance of the designed deck shows that the used design procedure is very efficient and safe. This procedure can be generalized for using in other areas of engineering.

MRA AND POD APPLICATION FOR AERODYNAMIC DESIGN OPTIMIZATION (MRA와 POD를 적용한 공력특성 최적설계)

  • Koo, B.C.;Han, J.H.;Jo, T.H.;Park, K.H.;Lee, D.H.
    • Journal of computational fluids engineering
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    • v.20 no.2
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    • pp.7-15
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    • 2015
  • This paper attempts to evaluate the accuracy and efficiency of a design optimization procedure by combining wavelets-based multi resolution analysis method and proper orthogonal decomposition (POD) technique. Aerodynamic design procedure calls for high fidelity computational fluid dynamic (CFD) simulations and the consideration of large number of flow conditions and design constraints. Thus, even with significant computing power advancement, current level of integrated design process requires substantial computing time and resources. POD reduces the degree of freedom of full system by conducting singular value decomposition for various field simulations. In this research, POD combined Design Optimization model is proposed and its efficiency and accuracy are to be evaluated. For additional efficiency improvement of the procedure, multi resolution analysis method is also being employed during snapshot constructions (POD training period). The proposed design procedure was applied to the optimization of wing aerodynamic performance. Throughout the research, it was confirmed that the POD/MRA design procedure could significantly reduce the total design turnaround time and also capture all detailed complex flow features as in full order analysis.

An Alternative Optimization Procedure for Parameter Design

  • Kwon, Yong Man
    • Journal of the Chosun Natural Science
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    • v.12 no.3
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    • pp.69-73
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    • 2019
  • Taguchi has used the signal-to-noise ratio (SN) to achieve the appropriate set of operating conditions where variability around target is low in the Taguchi parameter design. Taguchi has dealt with having constraints on both the mean and variability of a characteristic (the dual response problem) by combining information on both mean and variability into an SN. Many Statisticians criticize the Taguchi techniques of analysis, particularly those based on the SN. In this paper we propose a substantially simpler optimization procedure for parameter design to solve the dual response problems without resorting to SN.

A Novel Optimization Procedure Utilizing the Conformal Transformation Method (등각사상법과 유한요소법을 이용한 2단계 최적설계법)

  • Im, Jee-Won
    • Proceedings of the KIEE Conference
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    • pp.7-12
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    • 2001
  • A large number of methods for the design optimization have been proposed in recent years. However, it is not easy to apply these methods to practical use because of many iterations. So, in the design optimization, physical and engineering investigation of the given model are very important, which results in an overall increase in the optimization speed. This paper describes a novel optimization procedure utilizing the conformal transformation method. This approach consists of two phases and has the advantage of grasping the physical phenomena of the model easily. Some numerical results that demonstrate the validity of the proposed method are also presented.

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Data reconciliation for multicomposition processes (다성분 공정을 위한 데이터 보정)

  • 이무호;한종훈;장근수
    • 제어로봇시스템학회:학술대회논문집
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    • pp.36-39
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    • 1996
  • In chemical processes, measurement errors reduce the credibility of information and cause inconsistency in material and energy balances. Because multicomposition flows and temperature measurements make material and energy balances nonlinear equations, data reconciliation becomes a nonlinear constrained optimization problem. In multicomposition processes, if we follow general optimization procedure, the number of measurement variables is so large that data reconciliation requires much computation time. We propose the decomposition procedure to reduce the computation time without the decrease of accuracy of data reconciliation. Decomposition procedure finds global variables, that can reduce the nonlinearity of constraints, and divides two sub-optimization problems. Once we optimize the global variables at upper level, we can easily optimize the remain variables at tower level, We can obtain the short computational time and the same accuracy as SQP optimization method.

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Production of Alkaline Protease by Entrapped Bacillus licheniformis Cells in Repeated Batch Process

  • Mashhadi-Karim, Mohammad;Azin, Mehrdad;Gargari, Seyyed Latif Mousavi
    • Journal of Microbiology and Biotechnology
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    • v.21 no.12
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    • pp.1250-1256
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    • 2011
  • In this study, Bacillus licheniformis cells were immobilized by entrapment in calcium alginate beads and were used for production of alkaline protease by repeated batch process. In order to increase the stability of the beads, the immobilization procedure was optimized by statistical full factorial method, by which three factors including alginate type, calcium chloride concentration, and agitation speed were studied. Optimization of the enzyme production medium, by the Taguchi method, was also studied. The obtained results showed that optimization of the cell immobilization procedure and medium constituents significantly enhanced the production of alkaline protease. In comparison with the free-cell culture in pre-optimized medium, about 7.3-fold higher productivity was resulted after optimization of the overall procedure. Repeated batch mode of operation, using optimized conditions, resulted in continuous production of the alkaline protease for 13 batches in 19 days.

Design Optimization of Transonic Airfoils Based on the Navier-Stokes Equation (Navier-Stokes 방정식을 이용한 천음속 익형의 설계최적화 연구)

  • Lee Hyeong Min;Jo Chang Yeol
    • 한국전산유체공학회:학술대회논문집
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    • pp.177-185
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    • 1999
  • The airfoil design optimization procedures based on the Navier-Stokes equations were developed, This procedure enables more realistic and practical transonic airfoil designs. The modified Hicks-Henne functions were used to generate the shape of airfoils. Five Hick-Henne functions were used to design upper surface of airfoil only. To enhance the ability of Hick-Henne function to generate various airfoil shape with limited number of functions, the positions of control points were adjusted through optimization procedure. The design procedure was applied to the single-point design for the drag minimization problem with lift and area constraints. The result shows the capability of the procedure to generate much realistic airfoils with very small drag-creep in the low transonic regime. This is mainly due to the viscosity effect of Navier-Stokes flow analysis. However, in the higher transonic range tile drag-creep appears. The multi-point design is shown to be an effective way to avoid the drag-creep and improve off-design performance which is very similar in the Euler design.

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Optimal shape design of contact systems

  • Mahmoud, F.F.;El-Shafei, A.G.;Al-Saeed, M.M.
    • Structural Engineering and Mechanics
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    • v.24 no.2
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    • pp.155-180
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    • 2006
  • Many applications in mechanical design involve elastic bodies coming into contact under the action of the applied load. The distribution of the contact pressure throughout the contact interface plays an important role in the performance of the contact system. In many applications, it is desirable to minimize the maximum contact pressure or to have an approximately uniform contact pressure distribution. Such requirements can be attained through a proper design of the initial surfaces of the contacting bodies. This problem involves a combination of two disciplines, contact mechanics and shape optimization. Therefore, the objective of the present paper is to develop an integrated procedure capable of evaluating the optimal shape of contacting bodies. The adaptive incremental convex programming method is adopted to solve the contact problem, while the augmented Lagrange multiplier method is used to control the shape optimization procedure. Further, to accommodate the manufacturing requirements, surface parameterization is considered. The proposed procedure is applied to a couple of problems, with different geometry and boundary conditions, to demonstrate the efficiency and versatility of the proposed procedure.