• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2249-2251
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• 2001

This paper proposes that it minimizes interference between link at high speed trajectory tracking of 2-degree parallel link manipulator and QFT(Quantitative Feedback Theory) controller which robust structure uncertainty and disturbance of plant. And using ICD(Individual Channel Design), it separates two channel from multivariable system, parallel link manipulator and designs robust controller with applying MISO QFT to each channel. Finally, we make sure of robustness and excellence of QFT controller through simulation and experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.57-59
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• 2004

Arc-furnace is one of the large loads in the electric power system. When the arc-furnace operates, it may cause a bus voltage fluctuation in the power system, because it consumes a lot of reactive power. In this paper, we simulated this phenomenon by using a PSAF program with on-site measured arc-furnace load for different amount of cutailment load.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권4호
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• pp.226-231
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• 2000

In this paper, we present new method to analyze the space charge effect on the electrical characteristics in polymer. It is new measurement system and analysis method that have not reported yet. By using this measurement system, we make observation to space charge accumulated on the surface of polymer at AC voltage, so it is examined to verify the correlation of space charge and partial discharge(PD). In the result of experiment, it can be known that PD pattern is related more closely to space charge accumulated on the surface of polymer than in the inner part, and applied voltage in the air is ruled by this dynamic partial discharge. Also, above critical voltage, the space charge accumulated on the surface of polymer have no effect to the magnitude of PD and the applied voltage in the air. It has been known that the electric power of the dissolution system is proportioned to the frequency and the magnitude of applied voltage, but we can know by this result of the experiment that the efficiency of the dissolution is not related to the rise of voltage above critical voltage.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권4호
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• pp.153-158
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• 2003

This thesis deal with ferroelectric and ferromagnetic materials. PZT/Ferrite ceramics were made by the making process using PZT powder and garnet ferrite powder. PZT and ferrite are mixed as much 90%-10%, 50%-50%, and so on. After making samples, we are polishing samples until thickness is 0.1~0.2mm. We measured all kinds of samples in room temperature and applied magnetic field from -4500 to 4500 Oersted and conducted test of magnetical and electrical measurement using VSM and lpC resolution electrometer calibrated with RT66A pulsed tester. From this measurement, we can calculate tunability of these samples using C value obtained from P-E loop. As a result, it was able to measure magnetic characteristic when two matter had each other component ratio, and it was compound. However, it confirmed the possibility that was able to have ferroelectric characteristic with you in PZT 90% and ferrite 10%. Therefore, If this thing comes for PZT 50% and ferrite 50% have ferroelectric characteristic as him in a compound sample ore, can use this in an oscillator, supersonic waves detector in addition to a piezoelectric element. It may contribute to multipurpose of an element and demands such as a miniaturization of equipment, efficiency, reduce of a price which can use a characteristic of two components.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권10호
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• pp.515-522
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• 2004

In this study, we tried to investigate that the advantages of SOM(Self Organizing Map) algorithm such as data accumulation ability and the degradation trend trace ability would be adaptable to the analysis of partial discharge pattern recognition. For the purpose, we analyzed partial discharge data obtained from the typical artificial defects in GIS and XLPE power cable system through SOM algorithm. As a result, partial discharge pattern recognition could be well carried out with an acceptable error by use of Kohonen map in SOM algorithm. Also, it was clarified that the additional data could be accumulated during the operation of the algorithm. Especially, we found out that the data accumulation ability of Kohonen map could make it possible to suggest new patterns, which is impossible through the conventional BP(Back Propagation) algorithm. In addition, it is confirmed that the degradation trend could be easily traced in accordance with the degradation process. Therefore, it is expected to improve on-site applicability and to trace real-time degradation trends using SOM algorithm in the partial discharge pattern recognition

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권10호
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• pp.546-550
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• 2004

Two fabrication approaches are proposed to planarize the sacrificial layer over hollow structures. One is the photoresist filling method that makes use of photolithography, thermal curing and plasma ashing. The other is the lamination method that is applying pressure and temperature to the organic film over the hollow structures. The fabrication results are compared with those of CMP process. Trenches and cavities with various dimensions have been made for the porposed process. Upon measuring the planarization levels, they are dependent on planarization methods and the geometrical size of hollow structures. The photoresist filling method is so strongly dependent on the width and depth of trenches that we have problems to use it for large dimensional trenches. To the contrary, the flatness of sacrificial layer over the trenches was found to be almost independent of trench dimensions for the lamination method. A CMP process shows the most excellent results, but the fabrication is complicated and the access to it is not so easy. It is important to choose the proper planarization method by considering the required flatness levels, materials to be planarized, and connection between the planarization step and the previous or the following process of it.

• 전기학회논문지
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• 제59권12호
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• pp.2165-2172
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• 2010

This paper presents the operation algorithm of microgrid on the Real Time Pricing(RTP) for building the smart grid. RTP is higher power price variability than flat rate and time of use. However it has an effect on peak clipping and peak load shifting due to the increased price on peak time power demand. When the RTP are applied to the microgrid system, the proposed algorithm is able to be effective and economic operation. The implemented system is operated for the economic operation in microgrid connected with the power system. On the other hand, when the microgrid is operated on isolation mode, it focus on the improvement of stability and the power supply reliability of the sensitive loads. The test system are implemented and calculated on various operation modes based on non-dispachable generator output and RTP data for validating the proposed operation algorithm. The calculated results are compared to the implemented results using real-time simulator. It can be confirmed that the proposed operation system are identical results to the calculated one. When the proposed operation algorithm is applied to the system, it can be show the effectiveness of the peak clipping and peak load shifting and the improvement of economic feasibility.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.622-623
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• 2011

산업화시대 이래로 과학기술의 진보, 물질문명의 발달과 더불어 에너지 소비량도 폭발적으로 증가하여 왔다. 이로 인한 환경문제, 지구온난화 등 범지구적인 차원의 이슈가 발생하였다. 기후변화에 대처하기 위한 에너지 절약은 정책당국자, 학계, 산업계뿐만 아니라 일반시민들에게 있어서도 오랫동안 고민되어온 화두가 되어 오고 있다. 또한, 최근 발생한 일본의 원자력 방사능 유출건도 일본 수도권의 막대한 전기 소비량을 뒷받침하기 위해 건설된 발전소로 인한 2차 피해라는 측면에서 보다 안전하고 환경 친화적 재생적인 에너지에 대한 관심은 더욱 높아갈 수 밖에 없는 실정이다. 그러나 이를 위해 수많은 캠페인들이 행해져 왔음에도 불구하고 에너지 과소비는 여전히 해결되지 않고 있는 난제 중에 하나이다. 이러한 오랜 이슈를 해결하기 위해 기존의 에너지 절감 정책의 틀에서 벗어나 인간의 실질적인 소비행태에 변화를 주려는 대안 모색을 목표로 경제학의 새로운 패러다임인 행동주의 경제학의 프레임워크를 동원하여 효과적인 에너지 절감방안을 사람들의 제한적 합리성에 근거하여 모색하고자 한다. 더불어 이러한 시도는 최신 IT기술과의 융합을 통해 그 효율성을 극대화할 수 있을 것이다. 따라서 행동주의 경제학의 이론적 개념과 실질적인 적용사례를 살펴보고, IT기술의 융합을 시도할 때 고려해야할 사항들에 대해서도 논의를 전개해 나갈 것이다. 이를 통해, 효과적이고 효율적인 에너지 절감정책을 발견하기 위한 정보의 전달방식, 정보의 영향력, 편익측면의 제약사항 등에 대한 다양한 실험적인 연구들을 촉구하고자 한다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권6호
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• pp.387-394
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• 2000

This paper presents a method of cold gas flow-field analysis within puffer type GCB(Gas Circuit Breaker). Using this method, the entire interruption process including opening operation of GCB can be simulated successfully. In particular, the distortion problem of the grid due to the movement of moving parts can be dealt with by the fixed grid technique. The gas parameters such as temperature, pressure, density, velocity through the entire interruption process can be calculated and visualized. It was confirmed that the time variation of pressure which was calculated from the application of the method to a model GCB agreed with the experimental one. Therefore it is possible to evaluate the small current interruption capability analytically and to design the interrupter which has excellent interruption capability using the proposed method. It is expected that the proposed method can reduce the time and cost for development of GCB very much. It also will be possible to develop the hot-gas flow-field analysis program by combining the cold-gas flow field program with the arc model and to evaluate the large current interruption capability.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권12호
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• pp.567-572
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• 2002

In these days, diesel vehicle or power plant emits $NO_X\; and SO_2$ which cause air pollution like acid-rain, ozone layer destroy and optical smoke, therefore there are many kinds of methods considered for removing them such as SCR, catalyst, plasma process, and plasma-catalyst hybrid process. T$TiO_2$ is commonly used as catalyst to remove $NO_X$ gas because it have very excellent chemical characteristic as photo catalyst. In this paper, $NO_X$ sensing characteristic of $TiO_2$ thin film deposited by R.F Magnetron sputtering is investigated. A finger shaped electrode on $Al_2$O$_3$ substrate is designed and $TiO_2$ is deposited on the electrode by the magnetron sputtering deposition system. Chemical composition of the deposited $TiO_2$ thin film is $TiO_{1.9}$ by RBS analysis. When the UV is irradiated on it with flowing air, capacitance of $TiO_2$ thin film increases, however, when NO gas is put into the system with air, it immediately decreases because of photo chemical reaction. and it monotonously decreases with increasing NO concentration.