• 조명전기설비학회논문지
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• 제28권5호
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• pp.106-114
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• 2014

The interior permanent-magnet synchronous motor (IPMSM) is often used for the traction motor of hybrid electric vehicles (HEVs) and electric vehicles (EVs) due to its high power density and wide speed range. This paper introduces the 120kW class IPMSM for traction motors in military trucks. This system, as a SHEV (series hybrid electric vehicle), requires a traction motor that can generate high torque. This study introduces a way to reduce costs by proposing a design approach that creates reluctance torque that can be maximized by varying the dq-axis inductance. If a model designed by a design approach meets the desired torque, the magnetic torque can be reduced by an amount equal to the increase in reluctance torque and consequently the amount of permanent magnets can be reduced. A reduction gear and high speed operation of motors are necessary for the miniaturization of the motor. Thus, a fairly large centrifugal force is generated due to the high speed rotation. This force causes mechanical interference between the rotor and the stator, and a design approach for adding an iron bridge is explained to solve the interference. In this study, the initial model and the improved model that reduces cost and improves mechanical durability are compared by FEA, and the models are produced. Finally, the FEM results were verified experimentally.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.767-775
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• 2014

New material design has obtained tremendous attention in material science community as the performance of new materials, especially in nano length scale, could be greatly improved to applied in modern industry. In certain conditions limiting experimental synthesis of these new materials, new approach by computer simulation has been proposed to be applied, being able to save time and cost. Recent development of computer systems with high speed, large memory, and parallel algorithms enables to analyze individual atoms using first principle calculation to predict quantum phenomena. Beyond the quantum level calculations, mesoscopic scale and continuum limit can be addressed either individually or together as a multi-scale approach. In this article, we introduced current endeavors on material design using analytical theory and computer simulations in multi-length scales and on multi-physical properties. Some of the physical phenomena was shown to be interconnected via a cross-link rule called 'cross-property relation'. It is suggested that the computer simulation approach by multi-physics analysis can be efficiently applied to design new materials for multi-functional characteristics.

• 한국조경학회지
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• 제34권2호
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• pp.80-98
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• 2006

This study originated from following questions. What can we understand the conception of deconstruction, which has been the core idea of new discourses developed in various ways since modernism? How can this question be interpreted in landscape design? What is the conceptional frame of integration the prominent hybrid post-genre movements and phenomena? The frame can be epitomized with the deconstruction phenomenon. 'Deconstruction' is the core conception appeared in late or post-modern ages in the embodiment of modernity and can be viewed as an integrating or a hybrid phenomenon between areas or genres in formative arts. Therefore, the author regards the hybrid movements widely witnessed in the post contemporary formative arts as one of the most important indicators of de-constructive signs. It is safe to say that the phenomenon of this integration or hybridism, of course, does not threaten the identity of landscape design but serves as an opportunity to extend the areas of landscape design. One of the consequences of this integration or hybridism is the voluntary participation of users who have been alienated in the production of the meanings of design works and hybrid landscape design with the hybridization of genres that is characterized with transformation in forms. This view is based on the distinction between hybridization of interactions between the designer (the subject) and the user (the object), and hybridization of synesthesia. Generally speaking, this is an act of destroying boundaries of the daily life and arts. At the same time, it corresponds to vanishing of modern aesthetics and emerging of post-contemporary aesthetics which is a new aesthetic category like sublimeness. This types of landscape design tries to restore humans' sensibility and perceptions restrained by rationality and recognition in previous approach and to express non-materialistic characteristics with precaution against excessive materialism in the modern era. In light of these backgrounds, the study aims to suggest the hybrid concept and to explorer a new landscape design approach with this concept, in order to change the design structure from 'completed' or 'closed' toward 'opened' and to understand the characteristics of interactions between users and designs. This new approach is expected to create an open-space integrating complexity and dynamics of users. At the same time, it emphasizes senses of user' body with synesthesia and non-determination. The focus is placed on user participation and sublimity rather than on aesthetic beauty, which kind of experience is called simulacre. By attaching importance to user participation, the work got free from the material characteristics, and acceptance from the old practice of simple perception and contemplation. The boundaries between the subject and object and the beautiful and ordinary, from the perspective of this approach, are vanished. Now everything ordinary can become an artistic work. Western dichotomy and discrimination is not effective any more. And there is 'de-construction' where there is perfect equality between ordinary daily life and beautiful arts. Thus today's landscape design pays attention to the user and uses newly perceived sensitivity by pursing obscure and unfamiliar things rather than aesthetic beauty. Space is accordingly defined to take place accidentally as happening and event, not as volume of shape. It's the true way to express spatiality of landscape design. That's an attempt to reject conventional concepts about forms and space, which served as the basis for landscape design, and to search for new things.

• Computers and Concrete
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• 제14권4호
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• pp.445-462
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• 2014

To solve structural optimization problems, it is necessary to integrate a structural analysis package and an optimization package. There have been many packages that can be employed to analyze reinforced concrete plane frames. However, because most structural analysis packages suffer from closeness of systems, it is very difficult to integrate them with optimization packages. To overcome the difficulty, we proposed a possible alternative, DAMDO, which integrates Design, Analysis, Modeling, Definition, and Optimization phases into an integration environment as follows. (1) Design: first generate many possible structural design alternatives. Each design alternative consists of many design variables X. (2) Analysis: employ the structural analysis software to analyze all structural design alternatives to obtain their internal forces and displacements. They are the response variables Y. (3) Modeling: employ artificial neural networks to build the models Y=f(X) to obtain the relationship functions between the design variables X and the response variables Y. (4) Definition: employ the design variables X and the response variables Y to define the objective function and constraint functions. (5) Optimization: employ the optimization software to solve the optimization problem consisting of the objective function and the constraint functions to produce the optimum design variables. The RC frame optimization problem was examined to evaluate the DAMDO approach, and the empirical results showed that it can be solved by the approach.

• 한국실내디자인학회논문집
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• 제13권4호
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• pp.12-20
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• 2004

The purposes of this study were to identify styles of contemporary interior design, construct their images, and find out the relation of the identified styles to the structure images. Content analysis was used as the main method of this study, and the focus of the analysis was on a typological approach. Two hundred interior design photos were drawn from five different interior design magazines published in the past ten years, and ,they were analyzed by interior design professionals. Contemporary interior design was classified into ten styles: romantic, ethnic, classical, high tech, elegant, country, modern, minimal, natural, and causal. Given the ten styles, five images of interior design were identified - simple, comfortable, rustic, classical, and delightful. With regard to the relationships between 10 styles and 5 images of interior design, the this study found that the romantic style was related to the images of rustic and classical, the ethnic style to the images of comfortable, classical, and delightful, the classical style to the image of classical, the high tech style to the images of classical and rustic, the elegant style to the images of simple and classical, the country style to the images of comfortable and rustic, the modern style to the images of simple and delightful, the minimal style to the image of comfortable, the natural style to the images of comfortable and delightful, and the causal style to the images of comfortable and delightful.

• 응용통계연구
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• 제27권6호
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• pp.1029-1038
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• 2014

본 연구에서는 베이지안 실험계획법에 대하여 논의하고 간단한 모의실험을 통하여 최적화된 베이지안 실험계획법이 어떠한 특징을 가지고 있는지 설명하였다. 실험을 설계하는 경우 연구자는 관심있는 주제가 모수추정인지 아니면 예측인지를 결정하고 사전확률과 우도함수를 기반으로 이에 맞는 사후확률을 찾아 효용함수와 결합하여 최적의 실험설계를 찾는 것이 베이지안 실험계획법의 기본 원리이다. 만일 사전적 정보가 존재하지 않는다면 무정보적 부적합 사전확률을 이용하여 실험을 설계할 수 있으며, 이는 비 베이지안적 접근방법과 일치하게 된다. 만일 모수나 예측값에 대한 사전적 정보가 존재하는 경우에는 베이지안 실험계획법이 유일한 해결 방법이다. 하지만 모형의 복잡도가 증가하게 되면, 최적해를 찾는 과정이 매우 복잡해져서 극복해야 하는 많은 문제점들이 존재하므로 향후 많은 연구가 필요한 분야이다.

• 한국전산유체공학회지
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• 제11권1호
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• pp.57-66
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• 2006

An optimal shape design approach is presented for a subsonic S-shaped intake using aerodynamic sensitivity analysis. Two-equation turbulence model is employed to capture strong counter vortices in the S-shaped duct more precisely. Sensitivity analysis is performed for the three-dimensional Navier-Stokes equations coupled with two-equation turbulence models using a discrete adjoint method For code validation, the result of the flow solver is compared with experiment data and other computational results of bench marking test. To study the influence oj turbulence models and grid refinement on the duct flow analysis, the results from several turbulence models are compared with one another and the minimum number of grid points, which can yield an accurate solution is investigated The adjoint variable code is validated by comparing the complex step derivative results. To realize a sufficient and flexible design space, NURBS equations are introduced as a geometric representation and a new grid modification technique, Least Square NURBS Grid Approximation is applied With the verified flow solver, the sensitivity analysis code and the geometric modification technique, the optimization of S-shaped intake is carried out and the enhancement of overall intake performance is achieved The designed S-shaped duct is tested in several off-design conditions to confirm the robustness of the current design approach. As a result, the capability and the efficiency of the present design tools are successfully demonstrated in three-dimensional highly turbulent internal flow design and off-design conditions.

• 대한산업공학회지
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• 제28권4호
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• pp.407-414
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• 2002

The inherent reliability of a product is primarily determined in the design stage, and therefore, design engineers should be able to design reliability into the product in an efficient manner. Especially, the product should be designed such that its reliability is robust to various noise factors encountered in production and field environments. The Taguchi method can be effectively used for this purpose. However, there exist only a few attempts to integrate the Taguchi method with reliability design, and in addition, the existing works do not sufficiently consider the robustness and/or the distinction between noise and acceleration factors. This paper develops a unified approach to robust reliability design assuming that accelerated life tests are conducted at each combination of design and noise conditions. First, an experimental structure for assigning not only acceleration but also noise factors is presented. Second, the reliability at the use condition is estimated using the assumed accelerated life test model. Third, reliabilities are transformed into 'efforts' using an effort function which reflects the degree of difficulty involved in improving the reliability. Finally, an optimal setting of design parameters is determined based on the mean and standard deviation of the effort values. The above approach is illustrated with an example of a paper feeder design.

• 복식문화연구
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• 제28권6호
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• pp.890-911
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• 2020

This study proposed a base framework for creating sustainable designs with textile production waste and unused neckties with the "design thinking" approach, which is an iterative process. It aimed to set an example of how fashion designers can plan and manage their clothing design processes in a more sustainable way by recycling textile production scraps and unused neckties into unique clothing pieces with the upcycling method. Unused neckties and upholstery scraps were turned into skirts, blouses, and dresses by using creative techniques in line with current fashion trends. In addition, the five-stage iterative design process followed was explained, and the way in which the waste textile materials gained value by being converted into unique garments was discussed in terms of the user and the designer. Through the study, it was observed that the smallest amount of textile waste can be transformed into upcycled clothing via the iterative process, and original, value-added products enjoyed by consumers can be created. In addition, it was observed that the design thinking approach improves the understanding of the context of the problem, creativity in the generation of insights and solutions, skills to materialize those solutions through iterative prototyping, and the ability to combine these factors. Promising ideas to help designers develop recycling strategies were also provided.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1712-1725
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• 2022

For improving the seismic performance of the nuclear power plant (NPP) piping system, attempts have been made to apply a dynamic absorber (DA). However, the current piping DA design method is limited because it cannot provide the globally optimum values for the target design seismic loading. Therefore, this study proposes a seismic time history analysis-based DA optimal design method for piping. To this end, the Kriging approach is introduced to reduce the numerical cost required for seismic time history analyses. The appropriate design of the experiment method is used to increase the efficiency in securing response data. A gradient-based method is used to efficiently deal with the multi-dimensional unconstrained optimization problem of the DA optimal design. As a result, the proposed method showed an excellent response reduction effect in several responses compared to other optimal design methods. The proposed method showed that the average response reduction rate was about 9% less at the maximum acceleration, about 5% less at the maximum value of the response spectrum, about 9% less at the maximum relative displacement, and about 4% less at the maximum combined stress compared to existing optimal design methods. Therefore, the proposed method enables an effective optimal DA design method for mitigating seismic response in NPP piping in the future.