• Title/Summary/Keyword: Design Method

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

  • Jung Chul-Min
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.3 s.18
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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.

A Study on Precision Machining Technology for Disk Cams using Bi-arc Method (Bi-arc법을 이용한 평면 캠의 정밀 가공 기술에 관한 연구)

  • Shin J.H.;Kwon S.M.;Cho I.Y.;Kim J.C.;Kang H.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.235-236
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    • 2006
  • The disk cam mechanism can produce a positive motion with relatively few components. This paper introduce a shape design of cam using the relative velocity method and a precision machining technology for using Bi-arc method. The paper gives a machining information at each point using the Bi-arc method and the analysis method of the cutting error due to the moving path of the cutter, so that we can lead to the optimum design in a disk cam mechanism.

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An Efficient Dynamic Response Optimization Using the Design Sensitivities Approximated Within the Estimate Confidence Radius

  • Park, Dong-Hoon;Kim, Min-Soo
    • Journal of Mechanical Science and Technology
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    • v.15 no.8
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    • pp.1143-1155
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    • 2001
  • In order to reduce the expensive CPU time for design sensitivity analysis in dynamic response optimization, this study introduces the design sensitivities approximated within estimated confidence radius in dynamic response optimization with ALM method. The confidence radius is estimated by the linear approximation with Hessian of quasi-Newton formula and qualifies the approximate gradient to be validly used during optimization process. In this study, if the design changes between consecutive iterations are within the estimated confidence radius, then the approximate gradients are accepted. Otherwise, the exact gradients are used such as analytical or finite differenced gradients. This hybrid design sensitivity analysis method is embedded in an in-house ALM based dynamic response optimizer, which solves three typical dynamic response optimization problems and one practical design problem for a tracked vehicle suspension system. The optimization results are compared with those of the conventional method that uses only exact gradients throughout optimization process. These comparisons show that the hybrid method is more efficient than the conventional method. Especially, in the tracked vehicle suspension system design, the proposed method yields 14 percent reduction of the total CPU time and the number of analyses than the conventional method, while giving similar optimum values.

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Design of Spiral Spring in Sliding Mechanism for Mobile Phones Using Axiomatic Design (공리적설계를 이용한 휴대폰 슬라이드 기구의 스파이럴 스프링 설계)

  • Hwang, Eun-Ha;Han, Deok-Hee
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.3
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    • pp.171-177
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    • 2007
  • It is well known that mobile phones have been a indispensable communication tool for human life. The spiral springs are used as the main component of the semi-auto sliding mechanism of mobile phones. The characteristic of axiomatic approach is scientific and analytical method, and axiomatic approach is different from other design methods in offering the systematic method at an early stage of design. The axiomatic approach could determine design parameter and arrange the order of design and estimate the optimum design in good order. In axiomatic approach, the composition is divided by customer requirement, functional requirement, design parameter, and design matrix in large portion. This paper presents design in sliding mechanism for mobile phones by finite element method and axiomatic design.

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Genetic Algorithm Based Continuous-Discrete Optimization and Multi-objective Sequential Design Method for the Gear Drive Design (기어장치 설계를 위한 유전알고리듬 기반 연속-이산공간 최적화 및 다목적함수 순차적 설계 방법)

  • Lee, Joung-Sang;Chong, Tae-Hyong
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.5
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    • pp.205-210
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    • 2007
  • The integration method of binary and real encoding in genetic algorithm is proposed to deal with design variables of various types in gear drive design. The method is applied to optimum design of multi-stage gear drive. Integer and Discrete type design variables represent the number of teeth and module, and continuous type design variables represent face width, helix angle and addendum modification factor etc. The proposed genetic algorithm is applied for the gear ratio optimization and the volume optimization(minimization) of multi-stage geared motor which is used in field. In result, the proposed design optimization method shows an effectiveness in optimum design process and the new design has a better results compared with the existing design.

Design comparison of Fixed Offshore Structures Designed by WSD and LRFD Methods (허용응력설계법 및 하중저항계수설계법에 의한 고정식 해양구조물 설계결과 비교 )

  • Bae-Keun Jeong;Doo-Yong Cho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.2
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    • pp.42-49
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    • 2023
  • When designing fixed jacket structures, overseas design standards are applied due to the absence of domestic design methods. Although the US API standards are mainly applied, API RP 2A suggests two design methods: the allowable stress design method (WSD) and the load resistance coefficient method (LRFD), and is applied according to the designer's judgment. In this study, the stress ratio of the two design methods was reviewed and compared using SACS, an analysis program dedicated to marine structures, for fixed marine structures actually installed on the domestic coast. As a result of the review, it was found that the LRFD design method showed a greater stress ratio for extreme load analysis and transportation analysis, and the WSD design method showed a greater stress ratio for loading and lifting. Therefore, when applying the design method, it is considered appropriate to select the final design method considering safety and economic feasibility after conducting an applicability review for the two design methods.

DESIGN PROBLEM SOLVED BY OPTIMAL CONTROL THEORY

  • Butt, Rizwan
    • Journal of applied mathematics & informatics
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    • v.4 no.1
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    • pp.167-178
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    • 1997
  • In this paper we present an application to airfoil design of an optimum design method based on optimal control theory. The method used here transforms the design problem by way of a change of variable into an optimal control problem for a distributed system with Neumann boundary control. This results in a set of variational inequalities which is solved by adding a penalty term to the differential equation. This si inturn solved by a finite element method.

Technology for Initial Design and Analysis of Vehicle Pillar Structures for Vibration (저진동 차체의 필라 설계 및 최전화 기법)

  • 임홍재;이상범
    • Journal of KSNVE
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    • v.5 no.3
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    • pp.395-402
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    • 1995
  • In general low frequency vibration characteristics like an idleshake is mainly influeced by pillar section properties and joints. So the design technique development of vehicle pillar structures is required to initial design and vehicle development stage. In this paper to develop pillar structure design technique considering low frequency vibration characteristics, strain energy method, design sensitivity analysis method, and design optimization method using commercial finite element analysis program and optimization program are presented.

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Direct Inelastic Design for Steel Structures (강구조를 위한 직접비탄성설계법)

  • Eom, Tae Sung;Park, Hong Gun
    • Journal of Korean Society of Steel Construction
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    • v.16 no.2 s.69
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    • pp.181-190
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    • 2004
  • A new inelastic design method performing iterative calculations using secant stiffness was developed. Since the proposed design method uses linear analysis, it is convenient and stable in numerical analysis. At the same time, the proposed design method can accurately estimate the inelastic strength and ductility demands of the members by performing iterative calculation. In the present study, the procedure of the proposed design method was established. Design examples using the proposed method were presented, and its advantages were highlighted by comparisons with existing design methods using elastic or plastic analysis. Unlike the existing inelastic design methods performing the preliminary design on the structure and checking its validity using nonlinear analysis, the proposed integrated analysis-design method can directly calculate the strength and ductility demands of each member. In addition, the proposed design method can address the inelastic design strategy intended by the engineer, such as strength and ductility limits of members and the design concept of strong-column and weak-beam. As a result, economical and safe design can be achieved.

A Study on the Characteristics of the Creativity Development Teaching Method for Promoting Fashion Design Ability (패션디자인 능력 육성을 위한 창의성 개발 교육법 특성 연구)

  • Lee, EunRung
    • Fashion & Textile Research Journal
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    • v.20 no.2
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    • pp.156-166
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    • 2018
  • The purpose of this study is to present the suitable material that can be a real help to make the creativity development teaching method for creative inspirations of fashion design. To achieve these goals, researched and analyzed the creativity studies in the fields of psychology, education, and design (visual design, product design, fashion design, etc.) published in the national journal. Through this analysis, were extracted the characteristics of creativity, teaching methods for creativity learning, and expression methods. Based on this, intend to provide the creativity characteristic, the expression method, and the problem solving process in teaching methods for promoting fashion design ability. After the analysis, the results are as follows; First, the classical 4P (Place, Person, Process, Product) is important to a creativity development teaching method for fashion design. The elements of creativity of a creativity development teaching method for fashion design are 5elements; curiosity, openness, originality, patience, and synthetic ability. Second, the typical method is a drawing (such as a sketch) when visually express and embody ideas in fashion design. Drawing is an important activity that is working with the right brain and the left brain. Drawing exercises will reduce the burden of expressing ideas, providing pleasure and fulfillment in the development of creative ideas. Third, offered 5stages to solve problems of a creativity development teaching method for fashion design; understanding stage, idea stage, visualization stage, evaluation stage, and verification stage. Abstract intangible ideas are concreted and elaborated through stages of visual manifestation such as language, symbol, and drawing.