• 전기학회논문지
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• 제63권5호
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• pp.636-643
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• 2014

Length of most underground power cable in nation is not so long. Therefore it is operated without conductor transposition due to low unbalanced ratio. However, if cable length is long, line constant of each cable will be different. Different line constant can induce unbalanced voltage and current of sheath. Also it can induce several induced interference. This paper describes the operation effectiveness through steady and transient analysis on transposition and untransposition of cable conductor. Especially sheath current and induced voltage are analyzed and compared in case of transposition and untransposition. EMTP is used for modeling and analysis.

• 수산해양기술연구
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• 제21권1호
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• pp.19-27
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• 1985

우리 나라 연근해에 널리 분포하며 정치망에 주로 어획되는 부시리 Seriola aureovitta (TEMMINCK et SCHLEGEL)에 대하여 소비전력을 최소로 하면서도 동일한 주전반응이나 전기임비를 일으킬 수 있는 충격주파수와 펄스폭을 찾고자 전기자극실험을 행하였다. 주전반응과 전기임비를 일으키는 데 요하는 역치를 조사한 결과는 다음과 같다. 1. 주전반응과 전기임비를 일으키는 데 요하는 전력은 대체로 충격주파수가 낮을수록 감소하였다. 2. 전기임비를 일으키는 데 요하는 평균전력은 주전반응의 약 4.5~10배였다. 3. 주전반응과 전기임비를 일으키는 데 요하는 전력이 최소로 되는 펄스폭은 0.5msec 였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1603-1604
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• 2007

The load of power plants changes every from time to time according to which steam flow of boiler changes. the feed water control is very important for the power plant to be operated in its stability conditions. In case of circulation type boiler, the instability of feed water control leads to instability of drum level control. The higher level of drum water can induce bad quality steam to go into turbine which means the possibility of damage. The lower level of drum water can induce the tubes of boiler water wall to be overheated. In case of once through type boiler, the instability of feed water control leads to bad cooling of superheaters. The less the feed water flow is, the more heated the superheater is. It is necessary for the turbine driving feed water pump to be controlled for the optimal feed water flow in the large capacity power plant. The speed of turbine is controled for the feed water flow. By the way, the optimal control of steam valve is necessary for the speed control of turbine. Therefore, the various kinds of the steam valve structures are introduced in this paper

• 전기학회논문지
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• 제64권2호
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• pp.240-246
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• 2015

Length of most underground power cable in home is not so long. Therefore it is operated without transposition due to low unbalanced ratio. However, if cable length is long, line constant of each cable will be different. Different line constant can induce unbalanced voltage and current of sheath. Also it can induce several induced interference. This paper describes the effectiveness of transposition through sheath component analysis on transposition and untransposition of cable conductor. Especially sheath current and induced voltage are analyzed and compared in case of transposition and untransposition. EMTP is used for modeling and analysis.

• 마케팅과학연구
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• 제16권1호
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• pp.93-116
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• 2006

본 연구의 목적은 라디오 광고에서 정보원이 사용하는 언어 힘이 설득에 효과가 있는지를 관찰하고, 그 효과를 정보원의 성 그 자체의 효과와 비교해 봤을 때 과연 어떤 것이 설득을 결정하는 더 큰 요소인지를 알아보는 데 있다. 이 문제와 관련하여 선행 연구들은 일관성 없는 결괄르 보여주었다. 어떤 연구는 오디오 커뮤니케이션에서 언어 힘의 설득 효과는 학자의 성에 달려있다고 주장했고(Carli, 1990), 또 어ㅏ떤 연구는 오디오 커뮤니케이션에서 언어 힘의 설득 효과는 학자의 성에 관계없이 나타나는 굳건한 효과임을 주장했다(Holtgraves & Lasky, 1999; Erickson, Lind, Johnson, & O'Barr, 1978). 이에 본 연구는 라디오 광고에서 언어 힘과 정보원 성의 상호작용을 관찰함으로써 언어 힘의 설득 효과에 정보원의 성이 어떤 영향을 미치는지에 대한 실험적 증거를 제시하고자 했다. 실험 결과, 라디오 광고에서 정보원이 사용하는 언어 힘은 설득에 강한 효과가 있으며, 그 효과는 정보원 성의 영향을 받지 않는다는 것이 밝혀졌다. 이는 언어 힘의 지위 효과가 성의 지위 효과보다 더 강력하다는 것을 함축한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.85-88
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• 2000

Distributed Control System(DCS) is one of the best solutions to implement control systems because it provides continuous observation of control process and execution of commands to induce proper operations. In this paper, a design of control network for DCS in nuclear power plant is proposed. The proposed control network on DCS has a simple architecture and deterministic property. Thus, the proposed control network offers hard real-time periodic service. It also has redundant media for the fault-tolerance. As a result, high safety and reliability required in nuclear power plant are guaranteed.

• 대한안전경영과학회지
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• 제8권3호
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• pp.51-66
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• 2006

This study was attempted to analyze risk factors and suggest accident prevention in live line works for power transmission lines to be developed and applied in Korea. Safety problem cannot but occur at development of live line works and application to the field. With respect to this, problems likely to occur in the field among works adopting methods of works including live line works for power transmission lines were investigated and analyzed through documentary survey and risk assessment method. The results are summarized as follows. A risk assessment method model was suggested. This method enables scientific and systematic development of safety control. That is, the owner may autonomously induce safety control and build risk assessment database by work process to use them as best training data for workers. Also, in the field, it may induce all workers to participate in safety program and secure safety by making workers seek for safety working method under smooth flow from looking at risk factors to accident prevention activities. It is deemed that this humble study will prevent both accident and injury likely to occur in live line works for power transmission lines.

• Journal of Power Electronics
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• 제9권2호
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• pp.308-319
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• 2009

An increasing number of power electronic applications require high power density. Therefore, the switching frequency and switching speed have to be raised considerably. However, the very fast switching transients induce a strong voltage and current ringing. In this work, a novel damping concept is introduced where the parasitic wiring inductances are advantageously magnetically coupled with a damping layer for attenuating these unwanted oscillations. The proposed damping layer can be implemented using standard materials and printed circuit board manufacturing processes. The system behavior is analyzed in detail and design guidelines for a damping layer with optimized RC termination network are given. The effectiveness of the introduced layer is determined by layout parasitics which are calculated by application of the Partial Element Equivalent Circuit (PEEC) simulation method. Finally, simulations and measurements on a laboratory prototype demonstrate the good performance of the proposed damping approach.

• 한국정보통신학회논문지
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• 제24권5호
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• pp.666-669
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• 2020

Energy harvesting sensor networks have the ability to collect energy from the environment to overcome the power limitations of traditional sensor networks. The sensor network, which has a limited transmission range, delivers data to the destination node through a multi-hop method. The routing protocol should consider the power situation of nodes, which is determined by the residual power and energy harvesting rate. At this time, if only considering the magnitude of the power, power imbalance can occur among nodes and it can induce instantaneous power shortages and reduction of network lifetime. In this paper, we designed a routing protocol that considers the balance of power as well as the residual power and energy harvesting rate.

• 한국안전학회지
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• 제31권5호
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• pp.16-21
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• 2016

The purpose of this paper is to conduct ETA on 15 components of power installations: the DS/LBS, LA, MOF, CT, PT, A/V meter, VCB, OCR, COS, PF, Transformer, Condenser(C), Grounding, Cable and Connector. To achieve that, power installations work flow and its components are categorized. Based on performance, human, environmental, management, and safety, this paper drew Initiation events (IE) and End states (ES). ETA is applied to the main functions of each component, and the end states that may occur in one initiation event are suggested. In addition, detailed classification was performed to induce various end states on the basis of the suggested initiation events. If the suggested IEs and ESs are applied on the basis of power installations event cases, it is expected to prevent the same kinds of accident and operate power installations safely.