• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.318-320
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• 2000

This paper presents the develop-ment of electromagnetic wave detecting equipment for diagnosis of enclosed switchboard. High voltage power equipments are very important equipment of the key industries and the private enterprise power line accidents are national plans because of those set off casualties lose of power equipments and communication networks. Therefore the necessity of the development of detecting for power equipment diagnosis is demand for prevention of high voltage equipment accidents. This paper is the development of electromagnetic wave detecting equipment for diagnosis of high voltage equipment. This paper establishes the diagnosis method for high voltage power equipments, that secures original technique and possesses detecting technique for electromagnetic wave. By the study we developed electromagnetic wave detector and we applied this equipment application tests at the place constructed high voltage equipments.

• Proceedings of the KIEE Conference
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• 2005.11c
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• pp.80-82
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• 2005

Lightning surge damages of low voltage equipments in building are increasing due to increase in electrical and communication networks in the information-oriented society. And electrical circuits with semiconductor are very weak against lightning surge. To achieve effective method of surge protection on low voltage lines, there are needs for the relationship between propagation aspects of lightning surge and arrangement of indoor wire. This paper describes the experimental study on the relationship between them. This result may be raw data for establishment of surge protection system.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.899-901
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• 1996

KODAS is made up of the Central Control System(CCS) as four Vax workstations linked up with LAN networks, six Substation Communication Control Units(SCCU) installed in substation to transfer data, 125 Feeder Remote Units(FRU) located at the lower position of automated switch to provide the information of Fault Indicator(FI) and three kinds of automated switches to have remote control functions such as SF6 gas feeder automation switch, recloser and gas insulated pad mountes switchgear for under ground line. This paper explains the functions and characteristics in detail about each devices mentioned above.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1644-1646
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• 2003

This paper presents recent studies on the on-line insulation monitoring and diagnostic systems for transformers developed by HHI. Sufficiently high sensitivity and accuracy for practical use were achieved for the system, combined with communication networks to provide an on-line remote monitoring system. Several alarm criteria are formulated to enable a superimposed monitoring system to perform decisive action. The reasons for monitoring the condition and maintaining the health of electrical apparatus were discussed. The experience at the fields and the criteria for the judgment are also discussed in detail.

• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.91-93
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• 2004

This study presents recent trends on the on-line monitoring and diagnostic systems for oil-immersed transformers. Specially, our system on Yeo Su thermal power plant is introduced for high sensitivity and accuracy of ours. It is combined with communication networks to provide an on-line remote monitoring system. Several alarm criteria are formulated to enable a superimposed monitoring system to perform decisive action. The reasons for monitoring the condition and maintaining the health of electrical apparatus were discussed. The experience at the fields and the criteria for the judgment are also discussed in detail.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2037-2039
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• 2003

원자력 발전소의 원자로보호계통(Plant Protection Systems)은 그 특성상 안전성과 신뢰성을 중시하며, 매우 엄격한 설계 요건을 요구한다. 또한 원자로 보호계통에 사용되는 데이터 통신망은 최악의 예상된 조건에서도 신뢰할 수 있는 성능을 보여야 하며, 실증 시험을 통해 확인되어야 한다. 이러한 특성을 고려하여 국산화과제로 개발 중인 원자로보호계통의 데이터 통신망은, 개방형 통신 프로토콜인 프로피버스(Profibus)를 적용하고 있다. 본 논문에서는 적용된 통신 프로토콜인 Profibus에 대한 성능 모델을 제시하고, 제시된 성능 모델을 통해 데이터통신망이 결정론적(Deterministic) 요건을 만족한 수 있는 성능 특성을 분석하고자 한다. 이를 통해 Profibus를 적용한 데이터 통신망이 요구되는 성능, 신뢰성, 독립성 및 건전성 요건을 만족하도록 하기 위한 설계 요건을 제시하고자 한다.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.323-325
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• 1996

The design of Intelligent Energy Saving Power System Controller (IESPSC) for Telecom DC power plants is proposed and presented in this paper. From the past experience. rectifiers for Telecom DC power plants have been operated inefficiently at light loads. IESPSC offers "novel load sharing" approach based on the knowledge of each unit's efficiency of paralleled rectifiers. Neural networks is used for identifying each rectifier's efficiency characteristic curve corresponding to load currents, which is in turn utilized to produce a system efficiency close to the maximum under all operating conditions. In addition, by limiting the number of operating units to the minimum while maintaining high efficiency at the determined loads, a drastic savings in operating cost can be achieved.

• Journal of Sensor Science and Technology
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• v.13 no.1
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• pp.27-34
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• 2004

Camera calibration is an important and fundamental procedure for the application of a vision sensor to 3D problems. Recently many camera calibration methods have been proposed particularly in the area of robot vision. However, the reliability of data used in calibration has been seldomly considered in spite of its importance. In addition, a camera model can not guarantee good results consistently in various conditions. This paper proposes methods to overcome such uncertainty problems of data and camera models as we often encounter them in practical camera calibration steps. By the use of the RANSAC (Random Sample Consensus) algorithm, few data having excessive magnitudes of errors are excluded. Artificial neural networks combined in a two-step structure are trained to compensate for the result by a calibration method of a particular model in a given condition. The proposed methods are useful because they can be employed additionally to most existing camera calibration techniques if needed. We applied them to a linear camera calibration method and could get improved results.

• Journal of the Korean Society for information Management
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• v.6 no.1
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• pp.37-56
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• 1989

This study is a structural analysis of a multi-type and multi-level library network within the framework of a regional interlibrary loan (ILL) system. The study monitored to information network structure for resource sharing of academic and research library materials transmitted through the ILL. The local flow of academic and research information was measured by a survey of the filled ILL transactions by individual libraries in the Western 3Rs region. The major findings were as follows: 1) the regional ILL network showed less than half of participation of the total subject libraries, 2) existing structure surveyed was identified as a composite centralized network with three communication groups, 3) depending on the types of materials transacted, the structure were changed, 4) statewide and multi-state library cooperatives had direct interactions with some of the local libraries, 5) individual libraries participated in the ILL network more for periodicals than book materials, 6) academic libraries throughout the total six structure analyzed showed the highest percentage of participation.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.13-18
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• 2008

The 2005 west off Fukuoka earthquake with Mjma 7.0 occurred in the vicinity of Fukuoka city with 1.4 million populations, which had been regarded as rather seismically inactive in Japan. The strong motion records by K-net indicated PGV of 64 cm/s in Fukuoka city and some condominium buildings sustained extensive non-structural damages. In this study, we conducted a questionnaire survey for residents of 8 condominium buildings located in the downtown area of Fukuoka city after the earthquake. The results indicate that damaged nonstructural walls and distorted doors disrupted evacuation route for many occupants, and furniture and content damage on upper floors became severer resulting in higher rates of human casualty. Earthquake preparedness for indoor safety was raised after the earthquake, though further safety measures can be advised. In the phase of post-earthquake emergency and restoration period, residents' management organizations play important roles, so that neighborhood activities to promote communication networks are important in urban environment with aging population.