• 제목/요약/키워드: model based design

검색결과 12,214건 처리시간 0.047초

다구찌 직교배열의 반응표면모델에 의한 흡차음재 소재 DB 구축 (Construction of Insulator and Isolator Database by Using Response Surface Model based on Taguchi's Orthogonal Array)

  • 이광기;김병훈;전인기;강경순;김옥빈
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.619-624
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    • 2000
  • Design of experiments based on Taguchi's orthogonal array is utilized for exploring the design space and for building response surface models of insulator and isolator database in order to facilitate the effective solution of multi-objective optimization commonly occurred in NVH problems. Response surface models, called engineering database of design space, provide an efficient means to rapidly model the trade-off among many conflicting NVH goals in automotive. In the design of insulator and isolator in automotive interior part, it is important not only to construct effective matrices of NVH but also to build up engineering database of current products. The experimental design especially based on orthogonal array and the nonlinear optimization algorithms are successfully used together to obtain the optimal design of insulator and isolator. The $2^{nd}$ order response surface models of absorption coefficient and insertion loss are constructed by using modified Taguchi's $L_{12}2^13^7$ orthogonal array and successfully used in optimal design of insulator and isolator.

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A MATHEMATICAL MODEL FOR HISTORY-BASED ACCESS CONTROL

  • Kim, Hee-Young
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제8권1호
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    • pp.11-30
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    • 2004
  • Access Control is one of essential branches to provide system's security. Depending on what standards we apply, in general, there are Role-based access control, History-based access control. The first is based on subject's role, The later is based on subject's history. In fact, RBAC has been implemented, we are using it by purchasing some orders through the internet. But, HBAC is so complex that there will occur some errors on the system. This is more and more when HBAC is used with other access controls. So HBAC's formalization and model which are general enough to encompass a range of policies in using more than one access control model within a given system are important. To simplify these, we design the mathematical model called non-access structure. This Non-access structure contains to historical access list. If it is given subjects and objects, we look into subject grouping and object relation, and then we design Non-access structure. Then we can determine the permission based on history without conflict.

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GBAM 모델을 위한 새로운 설계방법 (A New Design Method for the GBAM (General Bidirectional Associative Memory) Model)

  • 박주영;임채환;김혜연
    • 한국지능시스템학회논문지
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    • 제11권4호
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    • pp.340-346
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    • 2001
  • 본 논문은 GBAM (general bidirectional associative memory) 모델을 위한 새로운 설계방법을 제시한다. GBAM 모델에 대한 이론적 고찰을 바탕으로, GBAM 기방 양방향 연상 메모리의 설계 문제가 GEVP (generalized eigenvalue problem)로 불리는 최적화 문제로 표현될 수 있음을 밝힌다. 설계 과정에서 등장하는 GEVP 문제들은 최근에 개발된 내부점 방법에 의하여 주어진 허용 오차 이내에서 효과적으로 풀릴 수 있으므로, 본 논문에서 확립된 설계 절차는 매우 실용적이다. 제안된 설계 절차에 대한 적용 가능성은 관련 연구에서 고려되었던 간단한 설계 예제를 통하여 예시된다.

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크리깅 근사모델을 이용한 강건설계에 관한 연구 (A Study on the Robust Design Using Kriging Surrogate Models)

  • 이권희;조용철;박경진
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.870-875
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    • 2004
  • Current trend of design technologies shows engineers to objectify or automate the given decision-making process. The numerical optimization is an example of such technologies. However, in numerical optimization, the uncertainties are uncontrollable to efficiently objectify or automate the process. To better manage these uncertainties, Taguchi method, reliability-based optimization and robust optimization are being used. To obtain the target performance with the maximum robustness is the main functional requirement of a mechanical system. In this research, the robust design strategy is developed based on the DACE and the global optimization approaches. The DACE modeling, known as the one of Kriging interpolation, is introduced to obtain the surrogate approximation model of the system. The robustness is determined by the DACE model to reduce the real function calculations. The simulated annealing algorithm of global optimization methods is adopted to determine the global robust design of a surrogated model. The mathematical problems and the MEMS design problem are investigated to show the validity of the proposed method.

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LNG 압력용기의 설계 (A LNG Pressure Vessel Design)

  • 김정위
    • Journal of Welding and Joining
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    • 제18권4호
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    • pp.28-37
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    • 2000
  • In this paper the LNG vessel of the Moss type which is capable of lifting 15,261 tons is investigated in the view point of the pressure vessel preliminary design using the finite element method. The Pressure vessel design is based on the equivalent stress levels due to the internal pressure. The finite element model of the spherical pressure vessel is configured using 4 noded quadrilateral shell element. The finite element analysis program NASTRAN and ANSYS 5.5are implemented. The design is compared with the three kinds of the boundary condition : first, where the equator of the pressure vessel is fixed, and where the top and is fixed, and, the bottom end is fixed, respectively. A comparison is presented between the results obtained by the finite element model and by the prototype production model. Additionally just below position(case 1 & case 2) of equator ring was carried out by using ANSYS 5.5. The results show that the vessel design based on the stress is acceptable at the preliminary design.

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PROCESS RESEARCH FOR DEVELOPMENT OF STRUCTURAL COST ESTIMATING MODEL BASED QUANTITY - FOCUSED ON PUBLIC OFFICE BUILDING PROJECT -

  • Soo-Min Kim;Jung-Kyu Seo;Sung-Uk Kim;Chang-Hyun Shin;Yung-Jin Kim;Jae-Youl Chun
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1170-1175
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    • 2009
  • When managers estimate exact construction cost at early stage and design phase, they can reduce construction cost in a more efficient way than to predict at construction stage. But, the current of public construction cost estimation and management is concentrated almost after detailed design phase. Therefore, construction cost management in design development phase to generally use approximate estimating is not correct. Also, the existing construction cost used the method that estimated by gross floor area-based cost estimates at design development phase. So, it is difficult to show the specific amount of materials and basis about the estimated cost of the construction. This study derived problems and limits of construction management at design development phase in case of public office building project through review of literature and current survey, and suggested estimating process model process of structural construction cost go improve these matters.

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MAO 모델을 사용한 관계 데이타베이스의 논리적 설계방법론 (A Logical Design Methodology for Relational Databases Using the MAO (Multiple Aspects-based Object) Model)

  • 조동영;백두선;황종선
    • 한국경영과학회지
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    • 제16권2호
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    • pp.49-64
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    • 1991
  • In this paper, we present a stepwise design methodology for relational databases using a new conceptual data model, the MAO(Multiple Aspects-based Object) model. Our methodology consists two steps : first, data requirements are conceptualized using the MAO model with concepts such as objects types and aspect types : second, the MAO model is transformed into the third normal form inn the relational model supported by commercial DBMs. A top-down approach is used for the MAO modelling in the first, step, and the transformation process in the second step can be automated. Our methodology supports easier and more database design of real world than other methodologies using existing data models.

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쾌속 배관 라우팅 방법을 적용한 선체 구조 모델 기반의 배관 모델링 시스템 개발 (Development of a Pipe Modeling System based on the Hull Structural Model Applying the Rapid Pipe Routing Method)

  • 노명일;최우영;이규열
    • 한국CDE학회논문집
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    • 제12권5호
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    • pp.321-329
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    • 2007
  • The present pipe modeling method requires detailed inputs from a designer to generate a pipe model, and thus it takes much time for the designer to perform such task. Moreover, the pipe model has no relation with the hull structure. Thus, it is time-consuming and requires much effort if design changes arise. In this study, a generating method that generates quickly many pipes using a pipe tray and a conversion method that converts automatically the pipes into objects related with the hull structure are proposed. A pipe modeling system based on the proposed methods is developed. The applicability of the developed system is demonstrated by applying it to the generation of the pipe model of a deadweight 300,000 ton VLCC(Very Large Crude oil Carrier). The results show that the developed system can quickly generate the pipe model in relation with the hull structure.

강교의 생애주기비용 최적설계 (Optimum Life-Cycle Cost Design of Steel Bridges)

  • 조효남;이광민;김정호;최영민;봉연종
    • 한국강구조학회 논문집
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    • 제15권4호통권65호
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    • pp.341-358
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    • 2003
  • 본 논문에서는 강교의 실용적인 생애주기비용 (LCC) 최적설계를 위한 일반화된 정식화와 LCC 설계시스템 모델을 제안하였다. 강교 최적설계를 위한 LCC는 초기비용, 직접 복구 (rehabilitation) 비용과 인적 혹은 물적 손실비용의 직접비용, 도로이용자비용, 그리고 사회-경제 손실비용을 포함한 간접비용의 현재가치의 합으로 정식화하였다. 특히 본 논문에서는 교량이 속해 있는 도로의 네트워크를 고려한 도로이용자비용과 사회-경제 손실비용 산정을 위한 새로운 모델을 제안하였다. 본 연구에서 제안된 LCC 정식화 모델은 실제 강박스 거더교와 강상판형교의 LCC 최적설계 문제에 적용하였고, 다양한 경우에 대한 LCC의 효율성에 대해 비교 고찰하였다. LCC를 고려한 강교량의 최적설계는 설계시방서에 기초한 설계방법뿐만 아니라 초기비용 절감을 위한 최적설계 방법과 비교할 때 더욱 합리적이고, 경제적이며, 안전한 설계를 유도할 수 있으리라 판단된다.

자오면 형상을 고려한 원심압축기 임펠러 최적설계 (Design Optimization of a Centrifugal Compressor Impeller Considering the Meridional Plane)

  • 김진혁;최재호;김광용
    • 한국유체기계학회 논문집
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    • 제12권3호
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    • pp.7-12
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    • 2009
  • In this paper, shape optimization based on three-dimensional flow analysis has been performed for impeller design of centrifugal compressor. To evaluate the objective function of an isentropic efficiency, Reynolds-averaged Navier-Stokes equations are solved with SST (Shear Stress Transport) turbulence model. The governing equations are discretized by finite volume approximations. The optimization techniques based on the radial basis neural network method are used for the optimization. Latin hypercube sampling as design of experiments is used to generate thirty design points within design space. Sequential quadratic programming is used to search the optimal point based on the radial basis neural network model. Four geometrical variables concerning impeller shape are selected as design variables. The results show that the isentropic efficiency is enhanced effectively from the shape optimization by the radial basis neural network method.