• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.695-700
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• 2008

Artificial neural network (ANN) has been extensively used in areas of nonlinear system modeling, analysis and design applications. Basically, ANN has its distinct capabilities of implementing system identification and/or function approximation using a number of input/output patterns that can be obtained via numerical and/or experimental manners. The paper describes a role of ANN, especially a back-propagation neural network (BPN) in the context of engineering analysis, design and optimization. Fundamental mechanism of BPN is briefly summarized in terms of training procedure and function approximation. The BPN based causality analysis (CA) is further discussed to realize the problem decomposition in the context of multidisciplinary design optimization. Such CA is also applied to quantitatively evaluate the uncoupled or decoupled design matrix in the context of axiomatic design with the independence axiom.

• 한국해양공학회지
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• 제18권4호
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• pp.59-64
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• 2004

Functional requirements and design parameters were not clarified in the early design process. Design axiom shows some difficulty for larger system designs, such as the butterfly valve, which is basically carried out by an incremental and iterative process. A numerical analysis was carried out on fluid flows in a butterfly valve, by using ANSYS-FLOTRAN. Characteristics of the butterfly flows at different valve disk opening angles, with a uniform incoming velocity, were investigated. The entire analysis is decomposed to satisfy the independence axiom. This paper resolves the problems associated with the establishment of a systematic design process.

• 경영과학
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• 제29권1호
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• pp.33-56
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• 2012

Domestic LCD TV market is composed of two groups of products produced by major firms and small and medium enterprises. The major companies make the price relatively high, but the other makes lower in the same sizes. The model of the low price products does not make consumers choice when they choose LCD TV. This makes the questions of capability between difference price products. The reason above mentioned, the firms that include group of comparatively lower price, are worried about not increasing sale because of prejudice. This study is to find any interrelationship and evaluate the efficiency between the products using performance, exterior and brand power of product. In order to do this, a hybrid AHP/DEA evaluation model for comparison/valuation of LCD TV products is developed. The proposed process is; first, to derive hierarchy structure of LCD TV evaluation criteria using axiomatic design, second, to calculate the score of each LCD TV product through AHP analysis including weight calculation of evaluation criteria, and last, to evaluate the efficiency of LCD TV product by applying DEA by defining product scores as output and prices as input. It concludes that the high price products shows good efficiency, but there are some products with good exterior and brand power, not performance, also presenting good efficiency.

• 대한기계학회논문집A
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• 제29권9호
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• pp.1270-1275
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• 2005

Rolling process to fabricate a strip with even thickness is significant to enhance the quality of the strip. The thickness of a strip can be effectively controlled by pair-cross mills. However, pair-cross mill generates thrust in the axial direction of roller and causes skewness, deflection, twist and even accidental roll chock failure. Therefore, accurate estimation of the thrust of the pair-cross mill during rolling process is necessary to monitor the failure of roll and the quality of products. An empirical equation given by Mitsubishi Heavy Industry (MHI) is hitherto employed, where the thrust is expressed in terms of rolling force, reduction ratio and crossed angle. However it turns out that the MHI empirical equation provides somehow inaccurate and unsuitable thrust in practical rolling processes. Moreover, we learn that three parameters involved in MHI equation are coupled each other. In this paper, axiomatic design principle is employed to select appropriate parameters involved in approximate equation in order to make parameters uncoupled. A quadratic equation using response surface method with new parameters is suggested. The accuracy of the approximate model is examined by comparing with real experimental data.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.355-356
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• 2006

This paper proposes an Molding error compensation method that improves accuracy with geometry information of injected parts using three-dimensional measuring instrument. a traditional mold design has been conducted by an experience-based trial and error, whereby generally the mold designer would decide the gate location and processing conditions. as a natural consequence, almost all creats inferior goods. It's just a process of trial and error and caught in a vicious circle. Due to this reason, this paper uses a three-dimensional measuring instrument, a commercial analysis package of injection molding(Moldflow, MPI) to analysis a state of flux. In addition to that axiomatic approach.

• 대한기계학회논문집A
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• 제31권10호
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• pp.999-1008
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• 2007

The spacer grid set is a component in the nuclear fuel assembly. The set supports the fuel rods safely. Therefore, the spacer grid set should have sufficient strength for the external impact forces such as earthquake. The fretting wear occurs between the spring of the fuel rod and the spacer grid due to flow-induced vibration. Conceptual design of the spacer grid set is performed based on the Independence Axiom of axiomatic design. Two functional requirements are defined for the impact load and the fretting wear, and corresponding design parameters are selected. The overall flow of design is defined according to the application of axiomatic design. Design for the impact load is carried out by using nonlinear dynamic analysis to determine the length of the dimple. Topology optimization is carried out to determine a new configuration of the spring. The fretting wear is reduced by shape optimization using the homology theory. The deformation of a structure is called homologous if a given geometrical relationship holds before, during, and after the deformation. In the design to reduce the fretting wear, the deformed shape of the spring should be the same as that of the fuel rod. This condition is transformed to a function and considered as a constraint in the shape optimization process. The fretting wear is expected to be reduced due to the homology constraint. The objective function is minimizing the maximum stress to allow a slight plastic deformation. Shape optimization results are confirmed through nonlinear static analysis.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.145-150
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• 2007

The spacer grid set is a component in the nuclear fuel assembly. The set supports the fuel rods saftely. Therefore, the spacer gl1d set should have sufficient strength for the external impact forces. The fretting wear occurs between the spring of the fuel rod and the spacer grid due to tile flow-induced vibration. The conceptual design of the spacer grid set is performed based on the Independence Axiom of axiomatic design. Two functional requirements are defined and corresponding design parameters are selected. The overall flow of the design is defined according to the application of axiomatic design. The design for the impact load is carried out by using nonlinear dynamic analysis to determine the length of the dimple. Topology optimization is carried out to determine a new configuration of the spring. The fretting wear is reduced by shape optimization using the homology theory. In the design to reduce the fretting wear, the deformed shape of the spring should be the same as that of the fuel rod. This condition is transformed to a function and considered as a constraint in the shape optimization process. The fretting wear is expected to be reduced due to the homology constraint. The objective function is minimizing the maximum stress to allow a slight plastic deformation. Shape optimization results are confirmed through nonlinear static analysis because the contact area becomes wider.

• 한국건설관리학회논문집
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• 제10권3호
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• pp.111-121
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• 2009

국내 건설업체들은 비용절감과 성능향상을 통해 고객의 요구를 반영하고자하는 노력의 일환으로 설계단계의 가치공학(Value Engineering, 이하 VE)을 적극적으로 검토하고 있지만, 실제 VE 활동에서는 고객의 요구가 충분히 반영되지 않고 있으며, 고객의 요구를 측정하는 준비단계에서 기능분석, 아이디어 창출단계에 걸친 순차적인 진행 또한 미비한 실정이다. 본 연구에서는 고객의 요구기능이 VE 수행절차에 체계적으로 반영될 수 있도록, 공리적 설계이론(Axiomatic Design Theory)을 설계VE 프로세스에 도입하여 기존의 설계VE 프로세스를 보완하는 고객만족형 설계VE 프로세스를 제안하고자 한다. 고객만족형 설계VE 프로세스는 설계VE와 공리적 설계의 프로세스 및 특성상의 유사성을 바탕으로 두 이론의 연계방안을 정리하고, 기존의 설계VE 프로세스에 공리적 설계 프로세스를 추가.보완하는 형태로 완성한다. 이때 프로세스의 초기단계인 고객의 요구를 측정하고 정리하는 과정에서, 거주 후 평가(Post-occupancy Evaluation)를 활용하는 방안을 제시한다. 설계VE에 거주 후 평가를 활용하기 위해 평가 기준 및 방법을 설정하고, 이를 바탕으로 고객요구 측정 절차를 수립하여 그 절차에 따라 설문을 작성한다. 본 연구의 결과는 지금까지 국내 설계VE 활동에서 미진하였던 고객요구를 적극 반영하고, 기능과 아이디어의 관계에서 기능-아이디어-기능의 지그재그 창출 방법을 통해 기능-아이디어간의 연계를 명확하게 하여, 체계적이고 효율적인 VE활동을 기대할 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1135-1136
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• 2011

• 오토저널
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• 제27권1호
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• pp.31-36
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• 2005