• Nuclear Engineering and Technology
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• 제41권9호
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• pp.1157-1170
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• 2009

A variety of Generation III/III+ reactor designs featuring enhanced safety and improved economics are being proposed by nuclear power industries around the world to solve the future energy supply shortfall. Nanofluid coolants showing an improved thermal performance are being considered as a new key technology to secure nuclear safety and economics. However, it should be noted that there is a lack of comprehensible design works to apply nanofluids to Generation III+ reactor designs. In this work, the review of accident scenarios that consider expected nanofluid mechanisms is carried out to seek detailed application spots. The Axiomatic Design (AD) theory is then applied to systemize the design of nanofluid-engineered nuclear safety systems such as Emergency Core Cooling System (ECCS) and External Reactor Vessel Cooling System (ERVCS). The various couplings between Gen-III/III+ nuclear safety features and nanofluids are investigated and they try to be reduced from the perspective of the AD in terms of prevention/mitigation of severe accidents. This study contributes to the establishment of a standard communication protocol in the design of nanofluid-engineered nuclear safety systems.

• 대한기계학회논문집A
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• 제26권5호
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• pp.914-923
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• 2002

Recently, there has been considerable interest in micro gyroscopes made of silicon chips. It can be applied to many micro-electro-mechanical systems (MEMS): devices for stabilization, general rate control, directional pointing, autopilot systems, and missile control. This paper shows how the mechanical design of the gyroscope can be done using axiomatic design, followed by the application of the Taguchi robust design method to determine the dimensions of the parts so as to accommodate the dimensional variations introduced during manufacturing. Functional requirements are defined twofold. One is that the natural frequencies should have fixed values, and the other is that the system should be robust to large tolerances. According to the Independence Axiom, design parameters are classified into a few groups. Then, the detailed design process is performed fellowing the sequence indicated by the design matrix. The dimensions of the structure are determined to have constant values fur the difference of frequencies without consideration of the tolerances. It is noted that the Taguchi concept is utilized as a unit process of the entire axiomatic approach.

• 대한기계학회논문집A
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• 제26권10호
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• pp.2073-2081
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• 2002

In product design and manufacturing, axiomatic design provides a systematic approach for the decision-making process. Two axioms have been defined such as the Independence Axiom and the Information Axiom. The Information Axiom states that the best design among those that satisfy the independence axiom is the one with the least information content. In other words, the best design is the one that has the highest probability of success. On the other hand, the Taguchi robust design is used in the two-step process; one is "reduce variability," and the other is "adjust the mean on the target." The two-step can be interpreted as a problem that has two FRs (functional requirements). Therefore, the Taguchi method should be used based on the satisfaction of the Independence Axiom. Common aspects exist between the Taguchi method and Axiomatic Design in that a robust design is induced. However, different characteristics are found as well. The Taguchi method does not have the design range, and the probability of success may not be enough to express robustness. Our purpose is to find the one that has the highest probability of success and the smallest variation. A new index is proposed to satisfy these conditions. The index is defined by multiplication of the robustness weight function and the probability density function. The robustness weight function has the maximum at the target value and zero at the boundary of the design range. The validity of the index is proved through various examples.gh various examples.

• 산업공학
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• 제21권1호
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• pp.96-108
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• 2008

This paper proposes the systematic design approach for developing the evaluation indicators that evaluate the candidate proposals in the national defense core-technology R&D projects. To improve the validity and fairness of the evaluation indicators, the existing evaluation process in a military and a public sector are surveyed and also the existing evaluation system of the core-technology R&D programs for the national defense is analysed and discussed. A new system for the evaluation indicators is designed by using the axiomatic design, factor analysis and the analytic hierarchy process. It is expected that the proposed evaluation indicators contribute to enhance the fairness and the reliability of the evaluation process for the proposal of the national defense core-technology R&D projects.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.445-450
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• 2001

DVD(Digital Versatile Disk) is the data storage media devised to make high storage density and high data input/output possible. Therefore higher rotational speed and better accuracy in optical pick-up are required compared with the existing optical storage device. These operational functional requirements are concerned with abilities of optical storage device. Especially, High rotational speed is deeply concerned with the noise and vibration of optical storage device, is important problem in development of optical storage device so much. This paper propose a new concept ROM media of optical storage device named as Cylindrical ROM media, and evaluate this by means of Axiomatic approach and empirical data.

• 대한기계학회논문집A
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• 제28권9호
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• pp.1368-1383
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• 2004

Robust design has been developed with the expectation that an insensitive design can be realized. That is, a product designed by robust design should be insensitive to external noises or tolerances. Robust design can be classified into three methods: (1) The Taguchi method (2) robust optimization (3) robust design by the axiomatic approach. In this paper, each method is reviewed and investigated. Pros and cons fur each method are discussed and a future direction for development is proposed.

• 대한기계학회논문집A
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• 제24권6호
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• pp.1479-1490
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• 2000

The design process of the motor driven tilt/telescopic steering column is established by axiomatic design approach in conceptual design stage. By selecting independent design variables for improvin g performance of the steering system, each detailed design can be carried out independently. In the detailed design, the safety in crash environment and vibration reduction are considered. An occupant analysis code SAFE(Safety Analysis For occupant crash Environment) is utilized to simulate the body block test. Segments, contact ellipsoids and spring-damper elements are used to model the steering column in SAFE. The model is verified by the result of the body block test. After the model is validated, the energy absorbing components are designed using an orthogonal array. Occupant analyses are performed for the cases of the orthogonal array. Final design is determined for the minimum occupant injury. For vibrational analysis, a finite element model of the steering column is defined for the modal analysis. The model is validated by the vibration experiment. Size and shape variables are selected for the optimization process. An optimization is conducted to minimize the weight subjected to various constraints.

• 대한기계학회논문집
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• 제9권5호
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• pp.647-654
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• 1985

본 논문에서는 미소한 비대칭 요소를 갖는 축대칭 셸구조물(종형구조물 또는 용접된 압력용기등)의 전산기 이용 도면입력/수정/출력, 체적특성치의 자동결정, 근사 고속 유한요소해석 및 출력을 시각화하는 일관 작업을 수행할 수 있는 전산기이용설계 알고리즘을 개발하고 생산가공에 대한 공리적 접근방법을 전산화하는 전산기이용 공정 계획 알고리즘에 대한 기초적인 연구를 행하였다.

• 한국자동차공학회논문집
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• 제13권3호
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• pp.24-34
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• 2005

The automobile seat must satisfy various safety regulations for the passenger's safety. In many design practices, each component is independently designed by concentrating on a single related regulation. However, since multiple regulations can be involved in a seat component, there may be design confliction among the various safety regulations. Therefore, a new design methodology is required to effectively design an automobile seat. The axiomatic approach is employed for considering multiple regulations. The Independence Axiom is used to define the overall flow of the seat design. Functional requirements (FRs) are defined by safety regulations and components of the seat are classified into groups which yield design Parameters (DPs). The classification is carried out to have independence in the FR-DP relationship. Components in a DP group are determined by using orthogonal away of the design of experiments (DOE). Numerical analyses are utilized to evaluate the safety levels by using a commercial software system for nonlinear transient finite element analysis.

• 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.