• Design & Manufacturing
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• v.1 no.1
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• pp.33-37
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• 2007

In recent, the demand of high-productivity injection mold increases because of the growth of international packaging market. The increase of productivity leads to the large-sized injection molding machine and peripheral devices. For solving this problem, the stack mold which is based on the existing machine and device is studied in advanced countries actively. In this study, as the preliminary research of stack mold development, the stack mold which has 2 Level ${\times}4$ Cavity is designed and manufactured. Besides, the motion and structural analysis are executed to verify the stability of developed stack mold.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.134-138
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• 2004

The discrepancies between theoretical values and measured data of PEFC(Proton Exchange Fuel Cell) is carried out for the machine tool power generation. Rudimental approach of theoretical fuel cell open circuit potential using Gibbs free energy is employed for the examination of PEFC module. The stack temperature, stack voltage and stack current are measured during the operation of PEFC module. It is found that stack voltage and current values show the pronounced discrepancy with the results calculated by Gibbs free energy approach. It is analysed that the discrepancy is due to activation polarization, concentration overvoltage and ohmic overvoltage.

• Journal of the Korea Society of Computer and Information
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• v.6 no.4
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• pp.100-103
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• 2001

The best solution to improve the execution speed of Java program is to make use of the high speed JVM(Java Virtual Machine). The performance of JVM depends on the difference of its implementation. One of the technologies to enhance JVM performance is a JIT(Just-in-Time) code generator. The JIT code generator transforms Java byte code to the native machine code in accordance with computer system platform. The native machine code is faster than the existing interpreter method, since it can reduce the time to analyze the Java byte code. But the JIT code generator have the problem of increasing the traffic between stack and register because of using many register. Therefore, this paper suggests how to reduce the traffic by applying the policy of stack allocation to JIT code generation, as one of the methods to enhance the performance of JVM.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.413-415
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• 1998

스택 머신 코드(stack-machine code)를 레지스터 기반 언어로 변환하는데 있어 스택의 타입 정보가 있으면 보다 효율적인 코드를 생성할 수 있음을 알아내었다. 본 논문에서는 스택 머신 코드의 타입을 분석해야 할 이유를 제기하고, 요약해석 방법론에 따라 분석 방법을 제시하고, 제시된 분석 방법의 안전성을 짚어 본다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.6
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• pp.92-96
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• 2003

Feul-Cell system consists of fuel reformer, stack and energy translator. Among these parts, stack is a core part which produces electricity directly. In order to set a stack module, fabrication of appropriate stack, design of water flow path in stack and control of coolant are needed. Especially, oater or air is used as a coolant to dissipate heat. The different temperature of each electric cell after cooling affects the performance of the stack. Therefore, it is necessary that the relationship between coolant hearing rate, width of stack, properties of stack, and the shape of water flow path must be understood. For the optimal design, the computational simulation by CFD-ACE has been conducted and the resulting database has been constructed.

• Design & Manufacturing
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• v.2 no.3
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• pp.28-31
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• 2008

In recent, the demand of high-productivity injection mold is increased because of the growth of international packaging market which is induced by an increase of population. The increase of productivity leads to the large-capacity injection molding machine and peripheral devices. For solving this problem, the stack mold which is based on the exsiting machine and device has researched in advanced countries actively. In this paper, as the preliminary research of stack mold development, the stack mold which has 2 level ${\times}4$ cavity was designed and fabricated. Besides, the motion and structural analysis were performed to verify the stability of developed stack mold.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.1-7
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• 2005

PEMFC (Proton Exchange Membrane Fuel Cell) is considered as an attractive option to produce electric power in manyapplications. A fundamental step of theoretical fuel cell open circuit potential is examined and compared with the measured data from 1.2KW PEMFC module. The hydrogen pressure and stack temperature are also measured during the operation of PEMFC module. It is found that the stack voltage and current data agree in general with the results calculated by chemical potential approach though they still have a discrepancy. It is analysed that the discrepancy is due to activation polarization, concentration overvoltage and ohmic overvoltage.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.14-18
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• 2003

Feul-cell system consists of fuel reformer, stack and energy translator. Among these parts, slack is a core part which produces electricity directly. In order to set a stack module, fabrication of appropriate stack, design of water flow path in stack, and control of coolant are needed. Especially, water or air is used as a coolant to dissipate heat. The different temperature of each electric cells after cooling and the high temperature of the stack affect the performance of the stack, Therefore, it is necessary that the relationship between coolant, healing rate, width of slack, properties of stack, and the shape of water flow path must be understood. For the optimal design, the computational simulation by CFD-ACE has been conducted and the resulting database has been constructed.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.6
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• pp.8-13
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• 2003

CFRP composite has a lot of merits such as mechanical characteristic, light weight and thermal resistance. For these merits CFRP is applied to so many industrial area. In order for the composite materials to be used in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joints must be provided, which require precise machining. In this paper, the relationship between the stack thickness and drill diameter is examined from the drilling experiment, which is the drilling of 16, 32, 48p1ies specimen with the ${\phi}8$, ${\phi}10$, ${\phi}12mm$ cemented carbide drill. The results are analyzed with consideration of cutting force, stack thickness and drill diameter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.381-382
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• 2007