• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.502-505
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• 2008

Due to continuous difficulty of human power supply, it is necessary to develop an equipment which is good to saving cost and time at a construction site. A quick pipe coupling method is the kind of mechanical joint system using split-sleeve and sealing-pad at pipe groove without welding. In hence, it provides restrained pipe joint which is simple, safe, and dependable without environmental pollutions. It is more useful scheme than the other ones. The purpose of this study is to find out the main design factors and the optimum shape of split-sleeve. The stress analyses were carried out under various shapes of pipe groove configuration, materials and internal pressures with a commercial software, ANSYS workbench which uses FEM(finite element method). Results are graphically depicted with various parameters.

• Journal of Information Display
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• 제13권4호
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• pp.151-157
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• 2012

A simple method of fabricating out-coupling structures was demonstrated via solution-processing to enhance light extraction from organic light-emitting diodes (OLEDs). Scattering layers were easily obtained by spin-coating an $SiO_2$ sol solution that contained $TiO_2$ particles. By introducing the scattering layer and the solution-processible corrugated structure as internal and external extraction layers, the OLEDs showed increased external quantum efficiency without a change in the electroluminescence spectrum compared to conventional devices. Using these solution-processible out-coupling structures, nearly all-solution-processed OLEDs with enhanced light extraction could be fabricated. The light extraction enhancement is attributed to the suppression by the out-coupling structures of the light-trapping that arose at the interface of the glass substrate and the air.

• Elastomers and Composites
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• 제25권4호
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• pp.280-290
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• 1990

The effect of surface treatment of kaolinite with silane coupling agent on the reinforcement of SBR was investigated. The possibility of the practical use of kaolinite as an organic filler was also scrutinized and it was found that the reinforcement of SBR was improved by modifying surface of the cheap inactive inorganic filler with organic silane coupling agents. 3-Chloropropyltrimethoxysilane(C-series), 3-mercaptopropyltrimethoxysilane(M-series) and 3-aminopropyltriethoxysilane(A-series) were used as coupling agents. To test the material properties of vulcanized and unvulcanized SBR, Mooney viscosity, modulus, elongation and fractured surface measurements by SEM were carried out by changing the amount of silane coupling agents. Torqe of the unvulcanized SBR following the measurement of the degree of vulcanization was to be increased as the amount of silane was increasing, and Mooney viscosity of M-series and A-series was also increased.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제14권5호
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• pp.370-376
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• 2004

The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it ispossible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way (uni-directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two-stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.969-972
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• 2003

The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it is possible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way(nl- directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding Point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure

• Journal of IKEEE
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• 제23권2호
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• pp.747-750
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• 2019

Wearable devices have become practically indispensable to daily life and helped people track and manage fitness, health, and medical functions etc. As these wearable devices become smaller and more comfortable for the user, the demand for longer run time and charging ways presents new challenges for the power management engineer. Wireless power transfer (WPT) is the technology that forces the power to transmit electromagnetic field to an electrical load through an air gap without interconnecting wires. This technology is widely used for the applications from low power smart phone to high power electric railroad and main electrical grid. There are two kinds of WPT methods: Inductive coupling and magnetic resonant coupling. The model using magnetic resonant coupling method is designed for a resonant frequency of 13.45 MHz. In this study, the hardware implementations of these two coupling methods are carried out, and the efficiencies are compared.

• Journal of the Korea institute for structural maintenance and inspection
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• 제12권5호
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• pp.152-160
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• 2008

Since wall system apartment used the shear wall as main lateral resistance member, installation of openings which causing section loss of walls may cause significant problem to structure. Also, there are few studies for inducing coupling beam or slabs which are occurred by installing openings. Therefore, this study planned isolated 2-story shear walls which are reduced three half-scale specimen to find out walls behavior characteristic. The test results showed that strength reduction caused by loss of effective section of walls and different result of stiffness and energy dissipation regarding to the coupling beam and coupling slabs.

• Journal of KIISE:Software and Applications
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• 제36권11호
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• pp.891-900
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• 2009

The priority of software maintenance researches has been increasing, since the lengths of software lifecycle are more increasing. Measuring couplings among software entities provides a good quantitative source for analyzing source code and point out candidate refactoring positions. Logical-coupling measures how strongly two software entities are related with each other from the evolutionary point of view. The researches on logical-coupling have been focusing on improving the correctness and explaining more aspects that are hiding by measuring logical-coupling among finer-grained entities. However, existing researches on logical-coupling fails to consider characteristics of developers and projects reflected in transactions. The research proposes a logical-coupling measurement method based on transaction time, size and expertise of developer to improve the correctness by considering characteristics of developers and projects reflected in transactions. The method has been validated by applying it to three open-source projects.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.840-843
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• 2004

UV molding is a process for integrating micro/nano polymeric optical components on optoelectronic modules. In the present study, a microlens array for vertical cavity surface emitting laser(VCSEL) to fiber coupling was designed, integrated and tested. At the design stage, design variables ware optimized to maximize the coupling efficiency, and tolerance analysis was carried out. At the integration stage, the UV transparent mold was fabricated and the microlens array on VCSEL array was integrated by UV molding process. Finally the coupling efficiency of VCSEL to fiber was measured and analyzed.

• Journal of Ocean Engineering and Technology
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• 제23권6호
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• pp.17-22
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• 2009

This study presents an investigation of the characteristics of piezoelectric sensors whose main utilization is to measure impact pressure. The piezoelectric sensors were tested from several points of view. Their characteristics were investigated for repeatability, the effect of the diameter, temperature effect, water purity, flush mounting, and AC and DC coupling. Out of these, it was revealed that the temperature effect is very significant. The characteristics of the AC and DC coupling are also very important in understanding the time history of the impact pressure.