• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.84-93
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• 2007

The pole transformer is one of the most important facility to insure the stability of electric power supply. which distributes electricity to customers directly. However there are a lot of defects which are caused by manufacturing fails(in 3 years) or deterioration (in 13 years), so we need a more improved transformer which insures quality. This thesis talks about the development of the new-type transformer using the hybrid insulation that is durable thermally, mechanically, and electrically. It would show how to lay out and produce the transformer using the hybrid insulation. And finally we are sure that we could increase the utilization rate of a transformer by 160% as compared with its own capacity through the overload test. Also, we carried out the examination about the short-circuit and insulation with a 100[kVA] model transformer, so that we expound the analysis of magnetic-mechanical forces intensity and the measure for improving short-circuit efficiency.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.1
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• pp.21-28
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• 2004

We have demonstrated the applicability of dry film photoresist (DFR) in photolithography process for fine pitch solder bumping on the polytetrafluoroethylene (PTFE/Teflon ) printed circuit board (PCB). The copper lines were formed with 100$\mu\textrm{m}$ width and 18$\mu\textrm{m}$ thickness on the PTFE test board, and varying the gaps between two copper lines in a range of 100-200$\mu\textrm{m}$. The DFRs of 15$\mu\textrm{m}$ thickness were laminated by hot roll laminator, by varying laminating temperature from $100{\circ}C$ to 15$0^{\circ}C$ and laminating speed from 0.28-0.98cm/s. We have found the optimum process of DFR lamination on PTFE PCB and accomplished the formation of indium solder bumps. The optimum lamination condition was temperature of $150^{\circ}C$ and speed of about 0.63cm/s. And the smallest size of indium solder bump was diameter of 50$\mu\textrm{m}$ with pitch of 100$\mu\textrm{m}$.

• Journal of IKEEE
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• v.23 no.2
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• pp.667-674
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• 2019

The recent incidents of Nuclear Power Plant(NPP) gave rise to a total power outage caused by the loss of the functions of the off-site and the emergency power supply. Currently, emergency power supply of NPP have been taken into account by Li-ion batteries instead of existing lead-acid batteries. In order to judge the applicability of the cylindrical Li-ion battery, it is necessary to analysis the results of various electrical tests. This paper investigates the basic electrical characteristics test of three types of cylindrical batteries in order to select the most suitable battery and estimate state of battery through equivalent circuit model and propose method to solve the problem.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.607-612
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• 2002

This paper presents the first domestic model product of hybrid Insulation low-loss type pole transformer, with increased overload ability, increased life, reduced loss, focusing improved short-circuit characteristics. The capacity of this transformer is 100 KVZ, rates first voltage 13200 V and secondary voltage 230/115 type. The volume of model transformer that was produced in high temperature using hybrid insulation can be reduced to 10-20% in comparison with that of present transformer with the same capacity. In this paper, we did short-circuit test and tested general characteristics of model transformer. In addition, we suggested design application new concept and methods thorough this experiment.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.91-94
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• 2002

It is important to develop new effective technologies for increasing the interruption capacity and reducing the size of a GCB (Gas Circuit Breaker). It is not easy to test the real GCB model in practice as in theory. Therefore, a simulation tool based on a CFD (Computational Fluid Dynamics) algorithm has been developed to facilitate an optimization of the interrupter. But the choice of grid is not at all trivial in the complicated geometries like a GCB. In this paper, we have applied a CFD-CAD integration using Cartesian cut-cell method, which is one of the grid generation techniques for dealing with complex and multi-component geometries.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2122-2126
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• 2007

A special PM-Tube(Photo Multiplier Tube) that is using the photoelectric effect has been designed and manufactured to measure the radiation energy of arc in a gas circuit breaker(GCB). The PM-Tube, LLG(liquid light guides), ND(neutral density) filter, and a model gas circuit breaker have been combined for the reception and the transmission of the light and a simplified synthetic test facility with the arc energy measuring system has been established. In the case of $SF_6$ gas pressure $5kg.f/cm^2$ and arc length 20mm, the radiation energy increases with the arc current but it tend to be saturated in the above 20kA. Under the arc current 20kA, the total radiation energy has the biggest value around 8kA and was not exceeded 40% of the total arc energy.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.63-71
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• 2006

In this paper, we consider a planning problem arising from printed circuit board manufacturing industries. Given a set of several types of PCBs, component feeders and surface mounting machines in series in a PCB assembly line, the problem is to define the feeder allocation and job sequence with the objective of minimizing the total operation time of the line. We formulate the problem as a mathematical model. And, the problem is proven to be NP-hard, so a genetic algorithm is developed. Finally, we give test results to evaluate the performance of the genetic algorithm.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.331-332
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• 2007

This Paper deals with the high sensitive camera circuit design, which is more sensitive than those on the market now in a way that it got rid of chronic smearing problem in CCD sensor and other kinds of noises in video signal effectively. This paper focused on the principle of CCD and video signal process and analyzed the specialized technique of industry and fundamental high sensitivity of CCTV camera. 1 also looked into the SONY super-HAD CCD camera which is very popular in the field now and compared this with the SONY EXview CCD camera to analyze the picture improvement using video test equipment. For the result, it had 190mv on camera sensitivity, 14dB on smearing, and 2dB on signal to noise ratio.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.134-136
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• 2001

In this paper, using equivalent circuit of BLDC motor in the 30W class, process of modeling the BLDC motor and calculating the parameter is shown. Through run-down-test and measuring back EMF, torque, speed and ampere, parameter that transfer function requires was gotten. In this result, for step response of BLDC motor, comparing the actual result obtained by circuit experiment with the simulation result obtained by substituting this parameter into the transfer function, it was established that process calculating parameters in this study is proper.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.317-319
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• 2007

Recently, there were many researches for efficiency improvement of DSC. Among of these works, research of surface treatment is still a prerequisite for electron diffusion, light-harvesting and surface state of $DSC^{4)}$. Using of the surface treatment, it can be raise up porosity of $TiO_{2}$ nano-crystalline structure on $photo-electrode^{5)}$. There are chemical, physical, electrical and optical methods which raise up its porosity. In this paper, we have designed and manufactured MOPA-type ultrasonic circuit (100W, frequency and duty variable). Manufactured ultrasonic circuit to use to force cavity density and power into $TiO_{2}$ paste. Then, we have optimized forcing time, frequency and duty of ultrasonic irradiation for surface treatment of photo-electrode of DSC. In I-V characteristic test of DSC, ultrasonic and thermal treated DSC shows 19% improved its efficiency against established DSC.