• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.131-141
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• 2004

This study deals with the procedure of safety improvement, productivity increase, and tact-time reduction through setting up the system about preventive maintenance. Actually, it is hard to establish and carry out preventive maintenance, even though we recognize the importance of the system concerning time, cost, labor, and so forth. In this study in the viewpoint of cost we are for achieving maximum efficiency by change and reduction of planning process adapted to the special work group. At first we briefly will mention the kind, the necessity, and the concept of preventive maintenance, and then divide the equipment used in the assembly line into the two whether it is necessary or not by way of estimating the breakdown loss, comparing with general establishment of preventive maintenance and modifying it to the case. At the second step we will establish the operation system of plan management related to production and quality in the special case. Check period and category will be set by dividing the assembly equipment into LCL and Focus in the third step. The forth step will contain the operation procedure in detail. And then we must make check and repair record periodically. Finally, on the basis of the record the selection of checking of significance will be conducted. This results in safety improvement, tact time reduction, and productivity improvement.

• Journal of Korea Multimedia Society
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• v.12 no.1
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• pp.58-68
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• 2009

With the rapid development of computer hardware and invention of various game-related technologies, the quality of games has been greatly improved and the genres of games have been diversified. Yet, in comparison, puzzle games have held to the past simple way of games, which has only led to a depression of the puzzle game market. This paper is the first attempt to overcome limits of the current puzzle games, by finding a breakthrough in three-dimensional puzzle games. In order to describe a realistic puzzle assembly in a three-dimensional puzzle game, this paper aimed to design a structure assembly technique made up of three steps that used a proper process to handle structure suitable to assembly, an elaborate way of collisions between individual objects and a physical structure. Through this technique, we intend to show in a simple experiment that it is possible to minimize the calculation cost in the assembly process and at the same time to achieve an elaborate puzzle assembly between structures.

• Nano
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• v.13 no.12
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• pp.1850146.1-1850146.9
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• 2018

The rapid development of smart textiles requires the large-scale fabrication of conductive fibers. In this study, we develop a simple, scalable and low-cost capillary-driven self-assembly method to prepare conductive fibers with uniform morphology, high conductivity and good mechanical strength. Fiber-shaped flexible and stretchable conductors are obtained by coating highly conductive and flexible silver nanowires (Ag NWs) on the surfaces of yarn and PDMS fibers through evaporation-induced flow and capillary-driven self-assembly, which is proven by the in situ optical microscopic observation. The density of Ag NWs and linear resistance of the conductive fibers could be regulated by tuning the assembly cycles. A linear resistance of $1.4{\Omega}/cm$ could be achieved for the Ag NWs-coated nylon, which increases only 8% after 200 bending cycle, demonstrating high flexibility and mechanical stability. The flexible and stretchable conductive fibers have great potential for the application in wearable devices.

• Journal of the Korea Society for Simulation
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• v.31 no.3
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• pp.23-34
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• 2022

Due to the characteristics of the railway system, a fleet consists of multiple railway vehicles, and a project contract is made by supplying multiple fleets to the customer. If the project fails to meet the due date, the manufacturer must compensate for the delay to the customer. In this paper, we analyze the operation strategies of the railway vehicle manufacturing factory using simulation, in which the layout adopts the concept of the flow lines, and when shortages of parts are considered. If there is a shortage of parts, the subsequent assembly process cannot proceed due to the nature of the assembly process. Thus, in order to overcome this problem, three strategies for performing assembly work are presented when the events of shortages are occurred. We also compare the strategies with respect to reduce the total cost which includes labor costs and compensation costs for delay.

• Journal of Applied Reliability
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• v.18 no.3
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• pp.229-239
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• 2018

Purpose: There is a difficulty in Environmental Stress Screening (ESS) test design for weapon system's electrical/electronic components/products in small and medium-sized enterprises. To overcome this difficulty, I propose an easy ESS test design approach algorithm that is optimized with only one environment tolerance design information parameter (${\Delta}T$). Methods: To propose the mass production weapon system ESS test design for cost-effective optimization, I define an optimum cost-effective mathematical model ESS test algorithm model based on modified MIL-HDBK-344, MIL-HDBK-2164 and DTIC Technical Report 2477. Results: I clearly confirmed and obtained the quantitative data of ESS effectiveness and cost optimization along our ESS test design algorithm through the practical case. I will expect that proposed ESS test method is used for ESS process improvement activity and cost cutting of mass production weapon system manufacturing cost in small and medium-sized enterprises. Conclusion: In order to compare the effectiveness of the proposed algorithm, I compared the effectiveness of the existing ESS test and the proposed algorithm ESS test based on the existing weapon system circuit card assembly for signal processing. As a result of the comparison, it was confirmed that the test time was reduced from 573.0 minutes to 517.2minutes (9.74% less than existing test time).

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.15-24
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• 2014

The study presents work information classification system of apartment house which can organize all construction management services throughout the planning and management of a construction such as the decomposition of the design process, the assembly of construction process and cost estimating, etc. In addition, the study suggested a way to connect work information classification system based on a relational database in working order and built a conceptual model for automated cost estimating by utilizing established data base. A conceptual model for automated cost estimating will resolve the fundamental problems of the existing cost estimating system and will be able to take advantage of scientific cost estimating system at the construction site of apartment house.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.256-262
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• 2014

Cycle length of domestic nuclear power plants is determined by the demand-supply plan of utility company. The target cycle length is achieved by adjusting the number of feed fuel assembly and fuel enrichment. Traditionally, utility company first select the number of feed fuel assembly and then find out the fuel enrichment to achieve the special cycle length. But it is difficult to find out if this method is most economical than any other combinations of the enrichment and batch size satisfying the same cycle length. In this paper, core depletion calculation is performed to find out the optimum combination of the enrichment and batch size for given target cycle length in terms of fuel cycle cost using commercial core design code; CASMO/MASTER code. To minimize the uncertainty resulting from transition core analysis, levelized fuel cycle cost analysis was applied to the equilibrium cycle core in order to determine the optimum combination. The sensitivity study of discount rate was also carried out to analyze the levelized fuel cycle cost applicable to countries with different discount rates. From the levelized fuel cycle cost analysis results, the combination with smaller batch size and higher fuel enrichment becomes more economical as the discount rate becomes lower. On the other hand, the combination with higher batch size and lower fuel enrichment becomes more economical as the discount rate becomes higher.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.6
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• pp.547-553
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• 2015

For commercialization of fuel cell electric vehicles, one of the key objectives is to reduce cost of full stack assembly. Regarding Membrane Electrode Assembly, the major issue is to improve fuel cell activation process in the initial Hydrogen Oxidation Reaction and Oxygen Reduction Reaction. In this research, the VD (Vacuum Drying) process has been developed for improvement of activation process. The VD condition is developed by controlling the temperature and degree of vacuum to remove the remaining solvent of electrode. Consequently, the electrode applied to VD process showed the low characteristics such as 3.5% of remaining solvent content and the improved efficiency such as 15% of activation process speed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.357-362
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• 2002

Most of battery industries are growing explosively as a core strategy industry for the development of the semi-conductor, the LCD, and the mobile communication device. In this thesis, dynamic characteristics of the steel can labeling machine on the automatic cell assembly line are studied. Dynamic characteristic analysis consists of dynamic behavior analysis and finite element analysis and is necessary for effective design of machines. In the dynamic behavior analysis, the displacement, velocity, applied force and angular velocity of each components are simulated according to each part. In the FEA, stress analysis, mode analysis, and frequency analysis are performed for each part. The results of these simulations are used for the design specification investigation and compensation for optimal design of cell manufacturing line. Therefore, Virtual Engineering of the steel can labeling machine on the automatic cell assembly line systems are modeled and simulated. 3D motion behavior is visualized under real-operating condition on the computer window. Virtual Prototype make it possible to save time by identifying design problems early in development, cut cost by reducing making hardware prototype, and improve quality by quickly optimizing full-system performance. As the first step of CAE which integrates design, dynamic modeling using ADAMS and FEM analysis using NASTRAN are developed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.727-730
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• 2002

Most of battery industries are growing explosively as a core strategy industry for the development of the semi-conductor, the LCD, and the mobile communication device. Dynamic characteristic analysis consists of dynamic behavior analysis and finite element analysis and is necessary for effective design of machines. In the dynamic behavior analysis, the displacement, velocity, applied force and angular velocity of each components are simulated according to each part. In the FEA, stress analysis, mode analysis, and frequency analysis are performed far each part. The results of these simulations are used for the design specification investigation and compensation for optimal design of cell manufacturing line. Virtual Engineering of the separator inserting machine on the automatic cell assembly line systems are modeled and simulated. 3D motion behavior is visualized under real-operating condition on the computer window. Virtual Prototype make it possible to save time by identifying design problems early in development, cut cost by reducing making hardware prototype, and improve quality by quickly optimizing full-system performance. As the first step of CAE which integrates design, dynamic modeling using ADAMS and FEM analysis using NASTRAN are developed.