• 제목/요약/키워드: Min-Design Method

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원통형 수중운동체 두부 형상 역설계 (An Inverse Design for Nose Shape of a Cylindrical-Shaped Submerged Body)

  • 정철민
    • 한국군사과학기술학회지
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    • 제7권3호
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    • pp.69-76
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    • 2004
  • In this paper, an efficient inverse design method for nose shape of submerged body based on the MGM(Modified Garabedian-McFadden) design method has been developed. The MGM design method is a residual-correction technique, in which the residuals are differences between the desired and the computed pressure distributions. 3-D incompressible Wavier-Stokes equation was adopted for obtaining the surface pressure distribution and combined with the MGM design method to perform the inverse design of nose shape of submerged body. The design method was verified by applying to several airfoil shapes. Improved design shapes could be obtained when the method was applied to nose shapes of submerged body.

준해석적 비선형 설계민감도를 위한 개선된 변위하중법 (Augmented Displacement Load Method for Nonlinear Semi-analytical Design Sensitivity Analysis)

  • 이민욱;유정훈;이태희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.492-497
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    • 2004
  • Three methods for design sensitivity such as numerical differentiation, analytical method and semi-analytical method have been developed for the last three decades. Although analytical design sensitivity analysis is exact, it is hard to implement for practical design problems. Therefore, numerical method such as finite difference method is widely used to simply obtain the design sensitivity in most cases. The numerical differentiation is sufficiently accurate and reliable for most linear problems. However, it turns out that the numerical differentiation is inefficient and inaccurate because its computational cost depends on the number of design variables and large numerical errors can be included especially in nonlinear design sensitivity analysis. Thus semi-analytical method is more suitable for complicated design problems. Moreover semi-analytical method is easy to be performed in design procedure, which can be coupled with an analysis solver such as commercial finite element package. In this paper, implementation procedure for the semi-analytical design sensitivity analysis outside of the commercial finite element package is studied and computational technique is proposed, which evaluates the pseudo-load for design sensitivity analysis easily by using the design variation of corresponding internal nodal forces. Errors in semi-analytical design sensitivity analysis are examined and numerical examples are illustrated to confirm the reduction of numerical error considerably.

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통계적 기법을 이용한 스핀드럼의 시밍 최적조건 선정 (Selection of the Optimum Seaming Condition for Spin Drum Using Statistical Method)

  • 김의수;이정민;김병민
    • 한국정밀공학회지
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    • 제25권1호
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    • pp.99-107
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    • 2008
  • There are being a lot of studies for achievement of high speed Dehydration, high-strength and Lightweight of washing machine in the latest washing machine business. It is essential that strength of mechanical press-Joining (MPJ) for spin drum is improved to attain that target. MPJ of spin drum is composed of seaming and caulking process. Because Seaming process of MPJ has various design factors such as thickness, bending radius, seaming width, caulking press width and the dynamic factor such as multistage plastic working, elastic recovery, residual stress, the optimum conditions can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor during drum MPJ and proposed optimum condition using center composition method among response surface derived from regression equation of simulation-based DOE.

정특성 및 동특성 해석을 통한 고속세탁기 주축의 형상 최적화 (The Shape Optimization of washing Machine Shaft for High-Speed Rotation through Analysis of Static and Dynamic Characteristics)

  • 김의수;이정민;김병민
    • 한국정밀공학회지
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    • 제25권5호
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    • pp.132-139
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    • 2008
  • To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Also, Vibration occurs due to the frequency of the rotating parts. But, shaft has various design factors such as diameter and distance between bearings according to configuration of shaft, the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using center composition method among response surface derived from regression equation of simulation-based DOE.

실험계획법을 이용한 스핀드럼의 시밍 최적조건 선정 (Selection of the Optimum Seaming Condition for Spin Drum Using Design of Experiment)

  • 김의수;이정민;김병민
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1511-1516
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    • 2007
  • Because Seaming process of MPJ (Mechanical Press Joining) has various design factors such as thickness, bending radius, seaming width, caulking press width and the dynamic factor such as multistage plastic working, elastic recovery, residual stress, the optimum conditions can't be easily determined. Using a design of experiment based on the FEM, which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor during drum MPJ and proposed optimum condition using center composition method among response surface derived from regression equation of simulation-based DOE.

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다정밀도 해석기법을 이용한 무인항공기 다분야통합 최적설계 (Multidisciplinary UAV Design Optimization Implementing Multi-Fidelity Analysis Techniques)

  • 이재우;최석민;누엔 반;김지민;변영환
    • 한국항공우주학회지
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    • 제40권8호
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    • pp.695-702
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    • 2012
  • 본 연구에서는 개념설계 단계에서의 해석 결과의 정확도를 높이기 위한 다정밀도 해석과 모든 분야의 요구도를 만족하기 위한 다분야통합 설계 최적화 기법을 적용하였다. 무인항공기의 해석을 위하여 경험식 기반의 저정밀도 해석도구들이 초기 사이징, 공력, 추진, 임무, 중량, 성능, 안정성 도구들로 모듈화되어 개발 및 검증되었다. 개발된 해석도구를 이용하여 설계통합 프로그램을 구성하고, 설계의 정확도를 증가시키기 위하여 다정밀도 해석에 와류 격자법을 이용하였다. 다분야통합 설계 최적화를 위하여 MDF 기법이 적용되었다. 또한 최적화 도구로는 구배기반 최적화 기법을 적용하였다. 제시한 방법의 타당성을 밝히기 위하여, 저정밀도 해석만을 적용한 방법과 다정밀도 해석을 적용한 두 가지 방법의 최적화 결과를 비교하여 본 연구에서 제안된 다정밀도 해석이 개념설계 단계에서 적용 가능함을 보였다.

실험계획법과 유한요소법을 이용한 주축계의 세레이션 형상 최적설계 (The Shape Optimal Design of Shaft Serration Using Design of Experiment and Finite Element Method)

  • 김의수;김병민
    • 한국정밀공학회지
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    • 제25권8호
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    • pp.72-79
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    • 2008
  • To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Shaft and flange connected by inserting shaft serration into flange on the process of die casting. When the system is operating, the gap is formed between serration and flange. But, Serration has various design factors and the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), this study was performed investigating the interaction effect between the various design factors as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using box-behnken method among response surface derived from regression equation of simulation-based DOE.

도시철도 지하박스 구조물의 내진성능 보강설계 연구 (A Study for the Performance Based Strengthening Design of Underground Box Structure in Urban Railway)

  • 권민호;김시격;김기홍;장영두;김진호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.1143-1148
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    • 2011
  • In this study, seismic structural reinforcement are carried out, based on the estimated seismic performance of underground box structures in urban railway, and displacement based design method was developed to enhance seismic performance of structures. New seismic reinforcement design method is proposed and compared with existing design methods. And presented an overview of the developed design methodology through a design example to verify the validity of that methods.

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상용 전자장 해석 프로그램 연동을 위한 전기기기 최적설계 인터페이스 개발 (Development of Interface Between Optimization Solver and Commercial EM Software for Design of Electromagnetic Devices)

  • 김민호;변진규
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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    • pp.45-48
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    • 2009
  • In this paper, we use the optimization design theory based on the finite element method and implement the optimal design of electromagnetic devices using COMSOL interface. COMSOL is one of the commercial EM software. Shape information for the design optimization is extracted by CAD in EM software. To calculate the shape of optimal design, sensitive analysis is applied to the design processing in MATLAB. To achieve the design objective in this paper, objective function is defined. According to the sensitive analysis based on the finite element method, we change the design variable after the sensitivity of the objective function is computed. To verify the proposed method, the results are compared with the initial design.

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지능적인 뉴로-퍼지 시스템의 설계 및 구현 (The Design and Implementation of An Intelligent Neuro-Fuzzy System(INFS))

  • 조영임;황종선;손진곤
    • 전자공학회논문지B
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    • 제31B권5호
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    • pp.149-161
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    • 1994
  • The Max-Min CRI method , a traditional inference method , has three problems: subjective formulation of membership functions, error-prone weighting strategy, and inefficient compositional rule of inference. Because of these problems, there is an insurmountable error region between desired output and inferred output. To overcome these problems, we propose an Intelligent Neuro-Fuzzy System (INFS) based on fuzzy thoery and self-organizing functions of neural networks. INFS makes use of neural networks(Error Back Propagation) to solve the first problem, and NCRI(New Max-Min CRI) method for the second. With a proposed similarity measure, NCRI method is an improved method compared to the traditional Max-Min CRI method. For the last problem, we propose a new defuzzification method which combines only the appropriate rules produced by the rule selection level. Applying INFS to a D.C. series motor, we can conclude that the error region is reduced and NCRI method performs better than Max-Min CRI method.

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