• Journal of Electrical Engineering and Technology
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• 제1권3호
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• pp.376-380
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• 2006

Temperature distribution measured to estimate the condition of an electrical apparatus is an absolute reference for the apparatus conditions and the difference between the reference temperature and the current temperature. Because of passive thermography, without the external thermal stimulation, the difference in surface temperature between the region of interest and back ground shows that the results can apply only to the estimation or the monitoring for the condition of loose terminal and the overload pertaining to the rise in temperature. However, a thermal diffusion in the active thermography is differently generated by the structure and condition of the surface and subsurface. This paper presents a nondestructive test using this behavior and deals with the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권4호
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• pp.180-183
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• 2004

This paper presents a description of the point collocation method and its application to the electromagnetic field computation. The interpolation scheme is based on the fast moving least square reproducing kernel approximation. In the method, the integration cell is not required and the essential boundary conditions can be enforced directly. Numerical simulations on 1-D and 2-D problems are carried out to validate the method. It is found that computational efficiency is higher than the general mesh-free methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.860-863
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• 2002

Recently, main nozzle and inner nozzle for EHV class gas circuit breakers were made by PTFE(Poly Tetra Fluoro Ethylen) for the basic material composite. But, nowadays strengthened PTFE was demanded because the supply of electric power increased. This paper shows the research results for nozzles according to the filler materials.

• 환경위생공학
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• 제16권2호
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• pp.38-46
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• 2001

In this work, the heterogeneous ion exchange membrane was used in a electrodialysis apparatus to treat a Ni planting rinse water because the heterogeneous ion exchange membrane was excellent efficiency as compared with low manufacturing cost, was easy to make, and had a good mechanical properties. For a regeneration of membrane and to obtain the optimal condition for a scale-up of apparatus after treating Ni plating rinse water, we would find about the limiting current density and the concentration polarization. When the Ni plating rinse water 150mg/L was treated with the electrodialysis apparatus using the heterogeneous ion exchange membrane, the limiting current density was about $1.49{\;}mA/\textrm{cm}^2$. And the limiting current density increased with the flow rate and concentration of Ni plating rinse water. We recognized that the used membrane could be reused by periodic backwashing because efficiency was constant when the membrane was backwashed after treating wastewater.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.562-570
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• 2002

The Purpose of this paper is to design and manufacture an educational system in order to demonstrate the causes and effects of electromagnetic induction.'rho educational system described in this study is a "jumping ring apparatus". This system demonstrates the principle of electromagnetic induction, a force from AC sources, Lenz's law of repulsion and transformer. The educational system is composed of a jumping ring apparatus, a sensor array, encoder, A/D converter, D/A converter and nonlinear controller. The educational system is controlled by 586 PC using Turbo C program. The sensor array is composed of 20 optical sensors. The nonlinear controller consists of nonlinear control algorithm and control board included SCR, FET and phase controller. The A/D converter is used to show the height of ring position to analog for an education purpose. The control signal calculated from the nonlinear control of algorithm send control board through 8 bit D/A convertor. Experiment results are given to verify that Proposed nonlinear controller is useful in on line control of the educational system.al system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.193-195
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• 1996

In amorphous transformer core, magnetic field annealing is required for inducing uniaxial magnetic anisotropy to circular direction of the core. Generally annealing temperature is about foot, so insulator using in solenoid bed must have a high temperature stability, mechanical strength and good machinability. In this study, we made the magnetic field annealing apparatus using insulators, conductors, connectors and power supply. And then tested the apparatus in annealing process of 50 kVA amorphous transformers.

• 한국건축시공학회지
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• 제5권4호
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• pp.139-144
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• 2005

A ground anchor system is used as a load carrying element in soil work. The conventional systems with ground anthers bring about the anchorage loss of wedges when anchors are installed for the support of soil structures. Hence we developed the new type of anchor system using both the spacing apparatus and spring (length 60mm, diameter 6mm). In this system, we tan directly check the condition of wedges and PS strands and modify the problems with the slip and anchorage of wedges under construction. For demonstrating the superiority of this system, we carried out a series of the laboratory test. Consequently, we can obtain satisfactory result (18.99$\%$ reduction to the loss of conventional systems). Moreover, the replacement of wedges is easy and simple when retensioning of strands.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1306-1311
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• 2004

The performance test apparatus of liquid-phase plate heat exchanger was installed and the computer program for design was developed in this study. The detail temperature distribution of hot and cold fluids in each path of heat exchanger was calculated by numerical method and the correlation for the heat transfer coefficient was defined. The heat transfer coefficients were measured using the working fluids of water and glycerine to investigate the effect of fluid viscosity. The measured heat transfer coefficients were compared with the calculated values obtained from the computer program and it was shown that error of the calculated values was generally less than 5%.

• 한국가구학회지
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• 제25권4호
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• pp.239-249
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• 2014

Color is an important subject of interest for cognitive developmental stages of children and it also correlate to emotional and physical development. Children can acquire concept of color by 'play'. Color play can be experienced to children through diversity activity and theses activities contain creative craft art activity. The color-paly with art activity for kids can be called 'kids color-design play'. Recently, indoor playgrounds are rapidly grow-up because parent's concern degree that about play activity get higher. The indoor playground being enlargement and it contains various paly contents. Color-design play is also enacted animatedly in kids indoor playground. The great part of color-design plays are enacted through program that needs teaching. On the other hand, color-design play facility that children can play spontaneously is not composed sufficiently. Therefore this study aim at design proposal of 'Kids color-design playground apparatus' in indoor playground.

• BMB Reports
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• 제36권3호
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• pp.265-268
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• 2003

Retinoic acid (RA) can transform the Golgi apparatus (GA) into a diffuse vacuolar aggregate and increase the toxicity of some immunotoxins that enter into cells by receptor-mediated endocytosis. An ultramorphological study of the RA-induced GA disruption was performed on F2000 fibroblasts. Cultures were treated with 0.11 to $30\;{\mu}M$ RA for 7 - 180 min. The endocytosis of Limax flavus agglutinin-peroxidase conjugate (LFA), and the interactions between a phorbol ester (PMA) and RA concerning GA disruption, were examined. Exposure to $0.33\;{\mu}M$ RA for 20 min transformed the GA into vacuolar aggregate. These vacuoles were not involved in endocytosis since they remained unstained after endocytosis of LFA. However, the lysosomes were involved in endocytosis, as they were strongly stained. Therefore, a RA-induced shift towards lysosomal routing of the entered LFA was presumed. Exposure to PMA made cells resistant to the Golgi-disturbing effects of RA, indicating that protein kinase C plays an important role in this process.