• 한국자동차공학회논문집
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• 제14권5호
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• pp.145-154
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• 2006

Each part of drum brake system is loaded by continual mechanical force and thermal force every time of braking, so enough strength and stability are required. Thermal characteristic is one of the important factors in drum brake systems design. This paper presents the thermal performance such as temperature distribution and thermal contact stress of drum brake system considering several braking patterns; 80th heat braking test mode, heat fade braking test mode, general road mode, steep slope road mode and off road mode. Transient heat transfer analysis and Thermo elastic contact analysis is executed to obtain the temperature distribution, and to evaluate thermal stress of drum brake by using ABAQUS/Standard code. This procedure of analysis can effectively be used to improve the quality problem of brake system and to get design guideline of the new product.

• 대한산업공학회지
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• 제41권5호
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• pp.470-480
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• 2015

There are many challenges in manufacturing system for new factory construction. Although factories produce same product, the layout of each factory may be different. The body shop in an automotive factory is a typical flow line with assembly, but the layout concept of the line varies among factories. In this paper, two types of layouts in the body shops of automotive factories, one for layered build and the other for modular build, are compared using simulation study. The simulation experiments indicate that the modular build layout is better than the layered build layout with respect to production rate. The effects of various failure distributions on the throughputs are also investigated, and some insights are suggested regarding the layout concept.

• 전기학회논문지
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• 제57권4호
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• pp.692-699
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• 2008

Semiconductor research and development(R&D) fabs are very different than production fabs in many ways such as the scales of production, job priority, production methods, and performance measures. Efficient operations of R&D fabs are very important to the development of new product, process stability, high yield, and ultimately company competitiveness. This paper proposes the fab-wide scheduling method for operational optimization of the R&D fabs. Most scheduling systems of semiconductor fabs have only focused on maximizing throughput of each separated areas without considering WIP(works in process) flows of entire fab. In this paper, we proposes the a fab-wide scheduling system which schedules all lots to entire fab equipment at once. We develop the MIP(mixed integer programing) model which allocates the lots to production equipment considering many constraints of all processes and the CP(constraint programming) model which determines the sequences of the lots in the production equipment. The proposed FAB-wide scheduling model is applied to the newly constructed R&D fab. As a result, we have accomplished the system based automated job reservation, decrease of the hot lot delay, increase of the queue time satisfaction, the high throughput by maximizing the batch sizes, decrease of the WIP TAT(Turn Around Time).

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권6호
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• pp.376-385
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• 2001

Considerable attention has been focused in recent years upon the field of biosorption for the removal of metal ions from aqeous effluents. Compared to other technologies, the advan-tages of biosortption are the high purity of the treated waste water and the cheap raw material. Really, the first major challenge for the biosorption field is to select the most promising types of biomass. Abundant biomass types either generated as a waste by-product of large-scale industrial fermentations particularly fungi or certain metal-binding seaweeds have gained importance in re-cent years due to their natural occurrence, low cost and, of course good performance in metal biosorption. Industrial solutions commonly contain multimetal systems or several organic and in organic substances that form complexes with metals at relatively high stability forming a very complex environment. When several components are present, interference and competition phe-nomena for sorption sites occur and lead to a more complex mathematical formulation of the process. The most optimal configuration for continuous flow-biosorption seems to the packed-bed column which gets gradually from the feed to the solution exit end. Owing to the com-petitive ion exchange taking place in the column, one or more of the metals present even at trace levels may overshot the acceptable limit in the column effluent before the breakthrough point of the trargeted metal. Occurrence of 'overshoot's and impact on havey metal removal has not been analyzed enough. New trends in biosorption are discussed in this review.

• Nuclear Engineering and Technology
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• 제19권3호
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• pp.180-185
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• 1987

월성로형 핵연료봉의 정상상태 노내거동 분석용 전산코드인 KAFEPA를 개발하였다. KAFEPA 전산코드는 같은 목적하에서 AECL에 의해 개발되었던 ELESIM 전산코드에 대응하지만, KAPEPA 전산코드는 ELESIM에 비해 보다 이론적이고 정확하게 예측하는 계산모형들, 즉, 핵분열기체방출 모형, 노내고밀화모형 및 중성자속 감소 계산모형들을 내포하고 있다. KAFEPA 전산코드는 핵분열생성물 기체 방출에 대한 22개 노내 실험자료에 그 예측치를 비교함으로써 검증되었다. KAFEPA 전산코드에 의한 예측치는 상기 실험자료와 잘 일치하였다.

• 한국정밀공학회지
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• 제21권9호
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• pp.135-141
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• 2004

Anti-shock performance is one of the most important design specifications of TFT-LCD modules. Since they are adopted fur major display units of many mobile applications such as lap-top PCs, cellular phones, and palm pilots, they are able to accommodate and endure high level transient mechanical energy inputs. For the reasons, not only the LCD unit manufacturers but their customers like PC makers perform a series of strict impact/drop test on the units. Currently, designers are mostly relying on their own trial-error based experience for the anti-shock design. Thus those designs depending on only experience may result in disqualification from the drop/impact test during final product evaluation. Those shock failures of any new designs are prohibitive for both LCD and PC manufacturers. In order to avoid this problem, many designers are focusing on the development of computer-aided design tools that is directly connected to shock simulation capabilities and then shock-proof design cycle time could be significantly reduced. Development of an integrated CAE system for the shock-proof design is presented in this article. At every stages of the development of present work, practical industrial applicability and mass production feasibility are seriously considered and tested so that the system is to be used in the LCD design engineering field.

• 한국정밀공학회지
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• 제29권9호
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• pp.978-985
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• 2012

Starfish are a critical problem for fishermen since they eat every farming product including shellfish. The number of starfish is increasing dramatically because they have no natural enemy underwater. We consider the concept of capturing starfish using a semi-autonomous robot. A new underwater robot design to capture starfish is proposed using cooperation between humans and the robot. A requirements list for the robot is developed and two conceptual designs are proposed. Each robot is designed as a modular platform. The kinematic and dynamic performance of each robot is analyzed and compared. This study is a starting point for developing a starfish capture robot and designing underwater robots for other applications. In the near future, a prototype will be assembled and tested in a marine environment.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권3호
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• pp.170-174
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• 2008

The measurement of performance of a process considering both the location and the dispersion of information about the process is referred to as the process capacity indices (PCIs) of interest, $C_{pk}$. This information is presented by the mean and standard deviation of the producing process. Linguistic variables are used to express the evaluation of the quality of a product. Consequently, $C_{pk}$ is defined with fuzzy numbers. Lee [Eur. J. Oper. Res. 129(2001) 683-688] constructed the definition of the $C_{pk}$ index estimation presented by fuzzy numbers and approximated its membership function using the "min" - norm based Zadeh's extension principle of fuzzy sets. However, Lee's result was shown to be invalid by Hong [Eur. J. Oper. Res. 158(2004) 529-532]. It is well known that $T_w$ (the weakest t-norm)-based addition and multiplication preserve the shape of L-R fuzzy numbers. In this paper, we allow that the fuzzy numbers are of L-R type. The object of the present study is to propose a new method to calculate the $C_{pk}$ index under $T_w-based$ fuzzy arithmetic operations.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.87-90
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• 2009

무선 메쉬 네트워크는 네트워크 구성의 용이성과 비용적인 장점으로 각광받고 있는 무선 백본 네트워크 기술이다. 최근 상용화된 제품이 출시되고 있지만, 대부분의 기존 연구 기술은 시뮬레이션을 통해 성능을 분석하였다. 본 논문에서는 실제 상황을 고려하여 무선 메쉬 네트워크 테스트베드를 구축하였다. 본 테스트 베드는 무선 분산 시스템(Wireless Distribution System)과 브릿지를 응용하여 멀티 채널 멀티 인터페이스와 동적인 위치기반 라우팅 프로토콜을 지원한다. 위치기반 라우팅 프로토콜은 링크 채널 변화와 물리적 거리를 고려한 메트릭을 이용하여 무선 간섭에 강하게 설계하였다. 그리고 메쉬 클라이언트들은 중앙 집중 주소 관리 서버를 통해 주소를 할당 받아 통신하며, 간이 망 네트워크 관리 프로토콜을 통해 망을 관리하도록 설계 및 구현하였다.

• 대한화장품학회지
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• 제28권1호
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• pp.202-213
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• 2002

There have been a lot of research going on for developing a new blend of cosmetic ingredients. such as Porous sphere power, High functional composition power, Ultrafine power, UV sunscreen agent, Flat titanium dioxide etc. It's said that these ingredients will have multi functional effects on foundation users. Regarding foundation products. UV care effect is basic and consumers want special feelings for skin and its'transparency. People also look for a high performance foundation which helps skin stay shineless and flawless with a longlasting beautiful finish. A lot of cosmetics are produced in small quantities resulting in a greater variety depending on consumers'ages, hobbies, trends, season and environment, so more specific cosmetics should be developed. To satisfy more specific clientele, It is expected that special care product will come out. Foundations for the elderly and men are already being considered as well as ones for trans-genders are possibility. It's considered that fecundation is not a makeup but something in skin-care categories based on the development and production of high performonce foundations.