• 한국생산제조학회지
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• 제23권1호
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• pp.32-37
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• 2014

Open-cell silicon foam is difficult to cut using conventional machining processes because of its low stiffness. That is, open-cell silicon foam is easily pressed down when the tool is engaged, which makes it difficult to remove the material in the form of chip. This study proposes an advanced method of machining open-cell silicon foam by freezing the material using liquid nitrogen. Furthermore, the machining conditions are optimized to maximize the efficiency of material removal and minimize the usage of liquid nitrogen by conducting experiments under various machining conditions. The results show that open-cell silicone foam products with free surface can be successfully machined by employing the proposed method.

• 경영과학
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• 제28권2호
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• pp.53-62
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• 2011

The objective of this paper is to propose a Binary Particle Swarm Optimization(BPSO) for design of reporting cell management system. The assignment of cells to reporting or non-reporting cells is an NP-complete problem having an exponential complexity in the Reporting Cell Location Management(RCLM) system. The number of reporting cells and which cell must be reporting cell should be determined to balance the registration(location update) and search(paging) operations to minimize the cost of RCLM system. Experimental results demonstrate that BPSO is an effective and competitive approach in fairly satisfactory results with respect to solution quality and execution time for the optimal design of location management system.

• 한국경영과학회지
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• 제22권4호
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• pp.133-149
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• 1997

The major two steps required to design a cellular layout are cell formation and cell layout. Because of the differences between manufacturing and assembly operations, the logic of cell formation and cell layout between an FMS and an FAS is not the same. Since the time for the assembly operations is usualaly relatively short, the transfer time is thus very crucial for the performance of assembly systems. Transfore in a cellular FAS it is more important to eliminate backtracking operations in assembly planning, not to allow intercellular movements in cell formation, and to arrange machines according to assembly sequence in cell layout. This study presents a method for the integrated layout design in cellular FASs considering the characteristics of FAS, layout, and production factors.

• 한국공작기계학회논문집
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• 제13권5호
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• pp.75-80
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• 2004

Feasibility of the small capacity fuel cell powered vehicle is carried out for system design with loading characteristics. The major design concepts which include battery, driving motor, and fuel cell module are analyzed and discussed for the future development. A load characteristics program is developed in order to calculate the traction power of fuel cell vehicle according to the driving courses specified. Further, the small capacity fuel cell vehicle is analyzed to determine the capacity of stack as a function of the velocity for an appropriate power required.

• 한국통신학회논문지
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• 제25권1B호
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• pp.48-55
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• 2000

본 논문에서는 전기장 프로브 교정용 비대칭형 TEM cell의 설계과정과 제작결과에 대해 나타내었다. 2cm$\times$2cm인 시험 공간(test space)에서 전자기장의 균일도가 $\pm$2 ㏈내를 유지하면서, 제1공진 주파수는 1.5GHz 이하에서 출현하도록 하고 제2공진 주파수는 약 GHz에서 출현할 수 있도록 제작하였다. 제작 결과 계산된 결과와 실험된 데이터가 일치함을 볼 수가 있었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.182-183
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• 2013

In the design of the fuel cell charger, it is important to find out the suitable topology and to design the converter to guarantee the performance of the fuel cell as well as the battery. Most of the chargers developed so far have used step-down converters. However, since the small fuel cell stack can only generate a low voltage, it is required to use the step-up converter to charge the battery. In this paper, a modified non-isolated boost charger topology for the Proton Exchange Membrane Fuel Cell (PEMFC) is proposed to meet the strict ripple requirements for the battery charge and its control method by using PI controller is detailed. The feasibility of the proposed topology and its control method is then verified by the experiments.

• 전기학회논문지
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• 제58권9호
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• pp.1706-1713
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• 2009

In this paper, a parallel operation algorithm for high power PEMFC generation systems is proposed. According to increasing the capacity of fuel cell systems with several fuel cell stacks, the different dynamic characteristics of each fuel cell stack effect on imbalance of load sharing and current distribution, so that a robust parallel operation algorithm is desired. Therefore, a power-sharing technique is developed and explained in order to design an optimal distributed PEMFC generation system. In addition, an optimal controller design procedure for the proposed parallel operation algorithm is introduced, along with informative simulations and experimental results.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2001년도 Bulletin of The 5th Asian Design Conference International Symposium on Design Science
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• pp.53.1-53
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• 2001

• 한국자동차공학회논문집
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• 제12권3호
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• pp.159-169
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• 2004

In this study, integration control of air-cell seat and semi-active suspension is proposed to minimize the road-tyre force which can cause uncomfortable feeling to rider. The proposed integration control with sliding perturbation observer is consisted of air-cell seat control which uses the force generated by air-cell and the sky-hook control. The air-cell seat itself has been modeled as a 1 degree of freedom spring-damper system. The actual characteristics of the air-cell have been analyzed through experiments. In this paper, we introduces a new robust motion control algorithm using partial state feedback for a nonlinear system with modelling uncertainties and external disturbances. The major contribution of this work is the development and design of robust observer for the state and the perturbation. The combination skyhook controller and air-cell controller using the observer improves control performance, because of the robust routine called Sliding Observer Design for Integration Control of Air-Cell Seat and Semi-active Suspension. The simulation results show a high accuracy and a good performance.

• 한국융합학회논문지
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• 제11권4호
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• pp.157-163
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• 2020

본 논문은 도시 생활구조물 활용을 위한 CIGS 태양전지 심미성 향상 제품디자인 개발융합연구로써, 기존 태양전지 패널의 문제점을 파악하고 제품디자인의 심미성 요소를 바탕으로 설문조사와 FGD [전문가 집단 토론]를 통해 CIGS 태양전지 심미성 향상을 위한 전문적인 심미성 요소를 도출하였다. 도출된 심미성 요소 중 '환경 조화성', '패턴 균형성', '시대 보편성' 이렇게 상위 3종을 콘셉트로 제품 디자인 프로세스를 진행하여 심미성 향상을 위한 CIGS 태양전지 모듈 디자인과 어셈블리 디자인을 도출하였으며, 제품 시뮬레이션을 통해 아파트, 베란다와 창호, 스트릿퍼니처에 적용했다. 본 연구는 추후 실제 도시 생활구조물에 활용해 심미성과 CIGS태양전지의 기능을 적용하기에 적합하며, 향후 연구방향은 다양한 패턴과 구조적 디자인개발에 관한 연구가 필요하다.