• 한국자동차공학회논문집
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• 제12권3호
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• pp.109-121
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• 2004

This paper presents an optimal design method for structure-borne durability of a vehicle body structure. Structure-borne durability design requires a new design that can increase fatigue lives of critical areas in a structure and must prohibit transition phenomenon of critical areas that results from modification of the structure at the same time. Therefore, the optimization problem fur structure-borne durability design are consists of an objective function and design constraints of 2 types; type 1-constraint that increases fatigue lives of the critical areas to the required design limits and type 2-constraint that prohibits transition phenomenon of critical areas. The durability design problem is generally dynamic because a designer must consider the dynamic behavior such as fatigue analyses according to the structure modification during the optimal design process. This design scheme, however, requires such high computational cost that the design method cannot be applicable. For the purpose of efficiency of the durability design, we presents a method which carry out the equivalent static design problem instead of the dynamic one. In the proposed method, dynamic design constraints for fatigue life, are replaced to the equivalent static design constraints for stress/strain coefficients. The equivalent static design constraints are computed from static or eigen-value analyses. We carry out an optimal design for structure-borne durability of the newly developed bus and verify the effectiveness of the proposed method by examination of the result.

• Journal of Mechanical Science and Technology
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• 제17권1호
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• pp.57-63
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• 2003

An eigenvalue design sensitivity formulation of a general nonsymmetric-matrix rotor-bearing system is devised. using the DDM (direct differential method). Then, investigations on the design sensitivities of critical speeds are carried out for an APU turbogenerator with a spline shaft connection. Results show that the dependence of the rate of change of the critical speed on the stiffness changes of bearing models of spline shaft connection points is negligible, and thereby their modeling uncertainty does not present any problem. And the passing critical speeds up to the 4th critical speed are not sensitive to the design stiffness coefficients of four main bearings. Further, the dependence of the rate of change of the critical speed on the shaft-element length changes shows quantitatively that the spline shaft has some limited influence on the 4th critical speed but no influence on the 1st to 3rd critical speeds. With no adverse effect from the spline shaft, the APU system achieves a critical speed separation margin of more than 40% at a rated speed of 60,000 rpm.

• 한국정밀공학회지
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• 제26권4호
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• pp.120-127
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• 2009

Spindle units of machine tool are very important part in the manufacturing area. Recently high speed machining has become the main issue of metal cutting. To develop high speed machine tools, a lot of studies have been carried out for high speed spindle. Due to increase of the rotational speed of the spindle, there has been renewal of interest in vibration of spindle. This paper concerns the improvement of spindle design using design of experiments. To improve the design of critical speed and weight of spindle, the experiments using central composite method have been carried out. The targets are critical speed and weight of spindle. For optimization of critical speed and weight and optimization of only critical speed by operation of all area search through response optimizer, the result of analysis has improved design of each factor. Finite element analyses are performed by using the commercial codes ARMD, CATIA V5 and ANSYS workbench. From the results, it has been shown that the proposed method is effective for modification of spindle design to improve critical speed and weight.

• 한국의류산업학회지
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• 제21권5호
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• pp.540-551
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• 2019

This study analyzes a new fashion phenomenon for critical fashion. Critical fashion is a message-centered fashion that delivers consciousness and sociocultural issues for contemporary society. The research method for this study combined literature reviews and case studies along with a research scope, that reviewed aspects of critical fashion through works, presentations, and images of collections, various media, and joint projects from the 2000s to the present day. This study indicates that critical fashion exhibits a conceptual pattern that metaphorically expresses the message of designers' perspectives on society and the fashion system. Critical fashion designers' socially critical messages began to emerge in avant-garde fashion influenced by avant-garde art movement that then developed into a conceptual fashion heavily influenced by conceptual art movement before it evolves into concepts of critical fashion. Critical fashion has been influenced by community-oriented critical art, which signifies that the characteristic of criticism of an art system is expressed through the language of fashion. In conclusion, critical fashion resists the idea of the integration of a cultural industry whose homogeneity is continuously collapsing the differences for the purpose of consumption and challenges to the established fashion system.

• 한국항공우주학회지
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• 제38권8호
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• pp.813-822
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• 2010

안전성 요구수준이 서로 다른 비행필수 데이터(Flight Critical Data)와 임무필수 데이터(Mission Critical Data)의 시현을 처리하기 위해 별도의 독립된 계기를 사용하지 않고 Glass Cockpit 설계를 적용하여 데이터를 통합처리하였다. 본 논문에서는 독립적으로 설계 진행되어온 비행조종계통과 임무탑재시스템의 통합설계를 위해 설계변경을 최소화하면서 비행조종계통에서 요구되는 비행필수 데이터처리의 안전성 요구수준을 만족시키는 최적화 설계를 제안하였다. 비행필수 데이터의 시현을 처리하기 위해 KUH 임무탑재시스템의 핵심구성품인 임무컴퓨터(Mission Computer)의 하드웨어 및 소프트웨어 설계변경을 최소화하였다. 임무탑재시스템의 안전성 요구도(Safety Requirement)를 검증하기 위한 시험절차를 개발하여 임무탑재시스템 통합시험장비(SIL)를 이용한 시험 수행 결과 안전성 요구도가 만족됨을 확인하였다.

• 한국실내디자인학회논문집
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• 제23권2호
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• pp.51-61
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• 2014

Aesthetics of use for modern people can be regarded as being weighted toward universal and rational function since it has focused on an 'automation and efficiency' and 'smartness' in terms of technological and human engineering position. Thus, aesthetics of use as an individual agent has remained in minimal level. This study attempts to seek conceptual model of design regarding the behavior of users from the systematization of critical theories about the usability. To do that, 'HERTZAIN TALES' written by Anthony Dune and the concept and system of Droog Design have been used as a core standard. In line with the various experiments by artist groups such as Fluxus, Memphis group and the work of product semantics, and inherent characteristics of Droog design, which has surfaced from the 1990s, concepts that has mentioned in the Hertzain tales have been organized into main texts. By overcoming cognitive bias inherent in the material culture and by overcoming an existing usability based on immateriality and dialectic solution, the autonomy of critical design and instrumentality of Droog design have been systemized. By interpreting the design aspect of 12 pieces that have been submitted to the RE;MIND section, the core of this study, it has been confirmed that conceptual and critical design's aesthetics of use From the interpretation of the design aspect of 12 pieces that have been submitted to the RE;MIND section, the core of this study, it has been confirmed that conceptual and critical design's aesthetics of use has established the autonomy and independence of the behavior of users, created functional articulation of materials and secured new conceptual model and thus, could be an effective methodical clue for creating an emergent design.

• 한국주거학회논문집
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• 제14권3호
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• pp.175-182
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• 2003

In this study, I investigate the critical evaluation elements at the architectural competition of the Rowhousing held nationwide in Germany. These evaluation elements, which can be regarded as the important design evaluation criteria, are selected by the design competition committee. Generally, in Germany the design competition committee consist of professors and famous architects who have theoretical and practical abilities with their own office. I classify and analyze the critical evaluation elements of 95 committee members, working on the selected 9 prize-winners in Germany from 1998 to 2002. I conclude that the critical evaluation elements, ordered by frequency are ; $\circled1$ context, $\circled2$ landscape & outside space, $\circled3$ arrangement of building, $\circled4$ circulation, $\circled5$ organization of plan, $\circled6$ economic aspects, $\circled7$ orientation of building, $\circled8$ parking, $\circled9$organization of form, $\circled10$ natural light. These design evaluation criteria for the Rowhousing in Germany also can apply to the korean case.

• Steel and Composite Structures
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• 제14권3호
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• pp.295-312
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• 2013

In this paper, a simplified approach based on critical temperature for fire resistance design of steel-concrete composite beams is proposed. The method for determining the critical temperature and fire protection of the composite beams is developed on the basis of load-bearing limit state method employed in current Chinese Technical Code for Fire safety of Steel Structure in Buildings. Parameters affecting the critical temperature of the composite beams are analysed. The results show that at a definite load level, section shape of steel beams, material properties, effective width of concrete slab and concrete property model have little influence on the critical temperature of composite beams. However, the fire duration and depth of concrete slab have significant influence on the critical temperature. The critical temperatures for commonly used composite beams, at various depth of concrete and fire duration, are given to provide a reference for engineers. The validity of the practical approach for predicting the critical temperature of the composite beams is conducted by comparing the prediction of a composite beam with the results from some fire design codes and full scale fire resistance tests on the composite beam.

• 공학교육연구
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• 제23권6호
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• pp.27-32
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• 2020

The aim of this paper is to explore various ways to utilize critical thinking in engineering education. To this end, this paper, in the light of the relationship between critical thinking and the program learning performance of ABEEK, reviews engineering design education, engineering ethics education, and engineering communication education, which are major areas where critical thinking can be utilized in engineering education. As a result, it was confirmed that critical thinking skills, especially the elements and criteria of critical thinking, can contribute to the creative problem-solving process in engineering design education, the rational decision-making process in engineering ethics education, and the effective communication process in engineering communication education.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.9-18
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• 2007

The success of a building design team is achieved as a result of a combination of multiple events/factors and interactions, and has a great impact on the quality of the building construction process. While most of previous studies have focused on quality of the construction process, the success of a design team has not been completely investigated. This paper presents the critical factors that impact the success of a building design team and describes an assessment tool to measure the successful performance of the design team with respect to the critical factors. The development of the assessment tool employs the concept of quality function deployment (QFD), a technique to measure the service quality of an organization.