• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1234-1242
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• 2013

To verify the effectiveness of the proposed system, the charges in power demand are analyzed for an AC and DC distribution system for the existing V2G concept and electric vehicle charging stations connected to a Battery Energy Storage System. In addition, since many power-converter-based chargers are operated simultaneously in an EV charging station, the change in the system harmonics when several EV chargers are connected at a single point is analyzed through simulations.

• Tribology and Lubricants
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• 제5권2호
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• pp.55-59
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• 1989

Measurement of the friction force of vane tip have been made to provide essential information for the study of the pump dynamics, the pump design and the analysis of triboligical problems in the sliding components. The influences of the radial load, rotating speed and frequency of vane on the friction forces of vane tip have been investigated. The results indicated that the friction coefficient of vane tip are affected by the rotating speed remarkably but the effect of acting load on the vane tip and frequency of load are very small. The stribecks diagram shows that the lubrication regime of the sliding point of vane tip is mixing lubrication.

• Advances in Computational Design
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• 제1권4호
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• pp.357-370
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• 2016

This paper aims to examine the dynamic response of a newly designed ultrasonic motor under half-sine shock impulses. Impact shock was applied to the motor along x, y or z axis respectively with different pulse widths to check the sensitivity of the motor to the shocks in different directions. Finite Element Analysis (FEA) with the ANSYS software was conducted to obtain the relative displacement of a key point of the motor. Numerical results show that the maximum relative displacement is of micro meter level and the maximum stress is five orders smaller than the Young's modulus of the piezo material, which proves the robustness of the motor.

• 한국전기전자재료학회논문지
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• 제18권10호
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• pp.891-895
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• 2005

Novel structure ultrasonic motors which have cross type stator were designed and fabricated. Driving characteristics of the motors were analyzed and measured by changing the materials of the stator. This ultrasonic motor has stator with hollowed cross bar and the stator rotate the rotor using elliptical displacement of the inside tips. This motion is generated by lateral vibration mode of cross bars. This stator was analyzed by finite element analysis depandent on stator's materials. And the cross type ultrasonic motors were made by analyzed results. The larger displacements were obtained, when the density of material was decreased. But the stress was increased when the stator's material has large density and Young's modulus. The fabricated one has high speed and torque in large stress on contact point between rotor and stator. The stress was more effected on speed and torque than the displacement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.205-207
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• 2005

In this paper, the Point of Common Coupling (PCC) is selected to analyze harmonic characteristic of distribution system by IEC 61000 - 3 - 6 in Electromagnetic Compatibility(EMC). Harmonic voltage and current were measured at the PCC of real distribution system. Harmonic distribution, nonlinear load component and Total Harmonic Distortion(THD) were verified by measurement. The effective and accurate modelling of real distribution system were proved through a analysis of harmonic impedance, voltage and current in steady-state. Harmonic transfer characteristic in distribution system were summarized and investigated through a analysis of harmonic voltage and harmonic current in harmonic current source.

• 제어로봇시스템학회논문지
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• 제15권8호
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• pp.786-791
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• 2009

Recently, digital camera module has been extensively utilized in mobile devices. The digital camera module should be smaller and lighter than digital still camera module to be used in mobile device. But, mobile camera can't get high quality image as good as the one of digital still camera due to the optical limitation of minimized module. Especially, AE system of mobile camera occurs excessive hunting and oscillation due to miniaturization of module. In this paper, improved AE algorithm which is applied fuzzy PI control is suggested to compensate this point.

• 대한화학회지
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• 제4권1호
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• pp.27-37
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• 1957

High-fire stain is influenced by the conditions of glaze, firing atmosphere, etc. On the contrary, low fire stain is not influenced by those conditions but obtainable in arbitrary colors and it is indispensable for pottery decoration. It is difficult for us to study into the color in the sphere of result publication method and expression of color. Looking over the literature on this subject, I have been confronted with much difficulties, accordingly, I made a basic and systematic experiment as to six low-firing stains (blue, green, blue-green, brown black and yellow) and made it proper to be applied in these studies. On pigment, I confirmed the influence of the assistant coloring matter by mixing up the coloring matter and the assistant coloring matter in various proportions. On flux, I measured the melting point by making PbO-$SiO_2$ system and PbO-$B_2O_3-SiO_2$ system and decided the range of usage. Also I checked the coloring by making the pigment on laze with pigment and flux manufactured, and concluded the pigment and flux adaptation to it.

• 한국농촌건축학회논문집
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• 제8권1호
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• pp.90-100
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• 2006

The purpose of this study is to suggest a actual conditions and expert's role on the green tourism in rural community. There are four types of green tourism in rural villages. It is an alternative tourism that has naturalism and sustainability, not mass tourism. I can find it is a one of the new rural development method in a point of view of rural people's income. Green tourism requires a participation of village peoples. So, management hang on not government office, but village people themselves. By surveying green tourism villages in the case of this study, I propose a few results as follow; firstly, green tourism of Korea will give an innovation to stagnant rural society. Secondly, rural people themselves must participate directly in development and guidance, when every programs are advanced. Thirdly, through this project of green tourism, we expect that urban and rural symbiosisically have a network.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.25.6-25
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• 2001

A new monitoring system is proposed to give direct visual information of the remote site when working with a tele-operation system. In order to have a similar behavior of a human when he is inspecting an object, multiple cameras that have different view point are attached around the robot hand and are switched on and elf according to the operator´s motion such as joystick manipulation or operator´s head movement. The performance of the system is estimated by performing comparison experiments among single camera (SC) vision system, head mount display (HMD)system and proposed multiple camera (MC) vision system by applying a task to several examines. The reality, depth feeling and controllability are estimated for the examines ...

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.241-246
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• 2000

Gas hydrates are solid solutions when water molecules are linked through hydrogen bondin create host lattice cavities that can enclose a large variety of guest gas molecules. The natural hydrate crystal may exist at low temperature above the normal freezing point of water and pressure greater than about 30 bars. A lot of quantities of natural gas hydrates exists in the ear many production schemes are being studied. In the present investigation, depressurization method considered to predict the production of gas and the simulation of the two phase flow - gas and - in porous media is being carried out. The simulation show about the fluid flow in porous have a variety of applications in industry. Results provide the appearance of gas and water prod the pressure profile, the saturation of gas/ water/ hydrates profiles and the location of the pl front.