• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.38
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• pp.9-15
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• 1996

The purpose of this research is to develop a method for part-machine grouping subject to production and management constraints. In the proposed integer programming model, minimization of operating and material-handling costs are considered as an objective function. The model allows one to recognize the existing parts and machines into disaggregated cells. New constraints are introduced in the model to resolve unbalancing capacity and bottleneck problems. It is found that this approach could have a better flexibility on cell size design for mote alternatives than conventional methods. Experimental grouping and comparison studies with ROC algorithm are given for evaluation purposes.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.153-158
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• 2000

This paper addresses an intelligent robot control system using an off-line programming to teach a precise assembly task of electronic components in a flexible way. The investigated task consists of three job: heat caulking test, soldering on a circuit board, and checking of soldering defects on the back cover of a camera. This study investigates the remodelling of the most complicated cell in terms of the accuracy and fault rate among the twelve cells in a camera back-cover assembly line. We have attempted to enhance back-cover assembly line. We have attempted to enhance soldering quality, to add task flexibility, to reduce failure rate, and to increase product reliability. This study modifies the cell structure, and improves the soldering condition. The developed all system implements the real-time control of assembly with vision data, and realized an easier task teaching on off-line programming.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.2
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• pp.23-27
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• 2008

As a biofuel source, direct photosynthetic/metabolic biofuel cells (DPBFC) use cyanobacteria whose photosynthesis and metabolization reactions can convert light energy to electricity, In our previous work, we fabricated a prototype micro-DPBFC that could generate a peak current density of $36{\mu}A/cm^{2}$ and a maximum power density of $270nW/cm^{2}$. In this study, we improve on the previous results by using carbon micro electromechanical systems (C-MEMS), formed from the pyrolysis of patterned photoresist, to fabricate carbon electrodes of an arbitrary shape and controlled porosity to increase the surface area. With these new C-MEMS electrodes, the maximum power density of the micro-DPBFC was $516nW/cm^{2}$, a performance twice as good as the results of our previous work.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.710-713
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• 2005

In this study, waffle type barrier ribs for counter electrode discharge cells were prepared via micro-molding process. The master mold was prepared by UV lithography and working mold was manufactured by replicating the master mold. The UV paste used in this study consisted of ceramic powders for the barrier ribs, binder, hardener, and dispersant was filled into cavities of a polymeric mold by action of capillary pressure developed between mold and paste. The results demonstrated a possibility of one-step process for the manufacturing of waffle type barrier ribs embedded with sustaining electrodes.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.4
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• pp.353-362
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• 2005

This article describes a state-of-the art review in nano-biomanipulation technologies. Nanomanipulation of biological objects enables an in-depth study of single molecules such as DNA and RNA, and of biophysical events at the molecular level like molecular motors. Controlled nanomanipulation is challenging but essential for precisely engineering biomolecules or cells and for manufacturing functional nano-biosystems. In this paper, we summarize several contact, non-contact and hybrid methods available for nanomanipulation of biological objects. Advantages currently available methods and their limitations are also compared. Finally, we discuss possible applications of nano-biomanipulation technologies to life science and molecular medicine including cell biology, genetic engineering, biophysics, and biochemistry.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.3
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• pp.65-74
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• 2005

본 연구는 기계고장 시 대체경로를 고려한 새로운 유사계수와 주어진 기간 내 수요변화를 고려하여 제조 셀을 구성하는 방법론을 개발하는 것이다. 본 연구의 방법론은 2단계로 나누어진다. 1단계에서는 기계고장 시 이용 가능한 대체경로를 고려하여 새로운 유사계수를 제시하고 유전자 알고리즘을 활용하여 부품 군을 식별하는 것이다. 셀 응용의 성패를 좌우하는 주요한 요소들 중 하나는 수요변화에 대한 유연성으로 수요변화, 이용 가능한 기계의 능력 및 납기일에 따라 셀을 재구성하기가 쉬운 일은 아닐 것이다. 대부분의 논문에서 제안한 방법들은 단일기간에 대한 고정 수요를 고려하였으나, 수요의 변화로 인하여 셀 설계는 대부분의 연구에서 고려한 단일기간보다는 장기적인 면을 고려해야 할 것이다. 수요가 변화하는 상황에서 운용요소와 일정요소를 고려한 셀 구성에 대한 새로운 방법론을 2단계에 소개한다.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.239-254
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• 1995

Automated Storage/Retrieval (AS/R) systems have been used mostly in manufacturing or distribution industry in order to store or retrieve palletized items automatically. Since the items ore heavy or bulky, only one pallet at a time is moved by the stacker crane In this study, however, we introduce the "multi -load" AS/R system in which the items to be stored are data storage devices of equal size such as video tape or compact disc. Since the items are small and light multiple items can be stored and retrieved in each trip by using a magazine and a robot arm mounted on the crane Given the magazine capacity, and the locations of retrieval items and empty cells in the rack, the throughput of the multi-load AS/R system will depend on the selection of storage locations and the sequence of visits. We propose four heuristic algorithms for the multi-command. Computer simulation is used to evaluate the four algorithms in terms of throughput and number of back tracking of the crane.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.448-451
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• 2000

The purpose of this study is to manufacture and test a thermoelectric generator which converts unused energy from close-at-hand sources, such as garbage incineration heat and industrial exhaust, to electricity. A manufacturing process and the properties of a thermoelectric generator are discussed before simulating the thermal stress and thermal properties of a thermoelectric module located between an aluminum tube and alumina plate. We can design the thermoelectric modules having the good properties of thermoelectric generation. Resistivity of thermoelectric module for thermoelectric generation consisting of 62 cells was 0.15-0.4$\Omega$ Developed thermoelectric modules can be expected th have better properties than thermoelectric cooling modules above $70^{\circ}C$ in temperature difference between hot and cold ends.

• Transactions of Materials Processing
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• v.21 no.1
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• pp.5-12
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• 2012

The weight of the bipolar plate is one of the crucial aspects of improving power density in PEMFC stacks. Aluminum alloys have good mechanical properties such as density, electrical resistivity, and thermal conductivity. Furthermore, using aluminum in a bipolar plate instead of graphite reduces the bipolar plate cost and makes machining easier. Therefore in this study, an aluminum alloy was selected as the appropriate material for a bipolar plate. Results from feasibility experiments with the aim of developing fuel cells consisting of Al bipolar plates with multiple channels are presented. Dynamic loading was applied and the formability of micro channels was estimated as a function of punch pressure and die radius. Sheets of Al5052 with a thickness of 0.3mm were used. For a die radius of 0.1mm the formability was optimized with a sine wave dynamic load of 90kN at maximum pressure and 5 cycles of a sine wave punch travel. The experimental results demonstrate the feasibility of the proposed manufacturing technique for producing bipolar plates.

• Journal of the Korean Solar Energy Society
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• v.28 no.5
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• pp.8-13
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• 2008

In this study, we analyze the electrical optical characteristics of transparent glass for photovoltaic and glass-glass module application. The elemental facts from raw glass to laminated glass with solar cells are analyzed using UV spectrophotometer and spectroradiometer. From the data of transmittance and reflectance, the optimum PV module processing condition and selection of material for fabrication should be considered deeply for obtaining high module efficiency. Also we introduce two glasses which has 2%$\sim$4% higher transmittance using coating technology with anti-reflection material. From this experiment, we try to give some basic information for PV module manufacturing industry. The detail description is specified as the following paper.