• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.706-712
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• 1998

Previous counter-current flow limitation (CCFL) and critical heat flux (CHF) studies included investigations on the inlet entrance, inclined channel and gap effects for the most part. In this study, the local CHF correlation was presented to be used in the numerical analysis for the 3 dimensional hemispherical geometry. Also, first-principle analyses were performed to determine the maximum heat removal capability from the debris through the gap that may be formed during a core melt accident. The maximum heat removal capability by gap cooling can be applied in quantitatively assessing the severe accident management measures.

• Proceedings of the KIEE Conference
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• summer
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• pp.1412-1414
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• 2004

Railway takes an important role of transporting massive passenger and freight. Accidents which occur related to trains have a risk of serious loss of lives, so those accidents need to be controlled urgently. Therefore moving picture transmission system is required which transmits exact information of moving picture of accident status to CTC and also communication line is also required with it. By using WTB line as a wayside transmission line, railway telephones, fax and train service information are provided to local offices. As transmission line improving project, optical cabling work is being processed by phases. Therefore optical fiber line is more effective way for a communicating way between stations than coaxial transmission line. This paper consider's connecting method when optical fibers is used for moving picture data transmission of train accidents and its problems.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.386-392
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• 1998

Previous counter-current flow limitation (CCFL) and critical heat flux (CHF) studies included investigations on the inlet entrance, inclined channel and gap effects for the most part. In this study, the local CHF correlation was presented to be used in the numerical analysis for the 3 dimensional hemispherical geometry. Also, first-principle analyses were performed to determine the Maximum heat removal capability from the debris through the gap that may be formed during a core melt accident. The maximum heat removal capability by gap cooling can be applied in quantitatively assessing the severe accident management measures.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.9-11
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• 2018

This paper studies on the development of an electric fire prevention system with the detection and alarm in case of parallel arc fault occurrence in low voltage distribution lines. The proposed detector has the characteristics of high speed operation responsibility and superior system reliability from composition using a large number of semiconductor devices. The line voltage is always feedback, and when an arc or a spark occurs, these are detected by the microcomputer. In addition, we design and develop algorithms using high speed and high precision microcomputer. A new conceptual control technique is adopted that RCD cuts-off by forming a forced short circuit between the phase voltage and ground in the event of an electrical accident. Some experimental tests of the proposed system also confirm practicality and the validity of the analytical results.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2221_2222
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• 2009

본 논문에서는 BLDC 운전 중 각 상의 결상 사고에 따른 토크 및 속도의 최적화에 대해 연구하였다. BLDC 모터의 구동을 위하여 ATmega16이 사용되었으며 제어기법으로는 PWM(Pulse Width Modulation) 기법이 사용된다. 속도 제어는 Hall Sensor의 검출 속도에 따라 Duty비를 제어하여 이루어지며 회전자 위치는 Hall Sensor 검출 방식을 통하여 이루어진다. 이러한 BLDC 모터를 이용하여 예기치 못한 결상 상황의 발생 시 토크의 감소로 인한 급제동에 대비하여 부하에 상응하는 토크를 최대한 낼 수 있도록 알고리즘을 구현하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1937-1942
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• 2016

Unlike oil immersed transformers, cast-resin transformers have the solid insulator 'epoxy resin' in sealed structure. Therefore, they reveal a lot of limitations in checking aging conditions and predicting an accident. This study analyzed the characteristics of Cast-resin transformers by the measurement distance and measurement sensitivity with a corona defect sample, using antenna sensor. Therefore, the experiment has proven that the antenna sensor-based measurement method proposed in this study is able to detect the insulation defect location of the cast-resin transformer, unlike conventional measurement methods. It is expected that the result of this study will be used to develop a new type of measuring method in order to measure insulation defects and to use in safety inspection of domestic cast-resin transformers.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.652-655
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• 2003

The human being receives a new information from outside and the information shows gradual oblivion with time. But it remains in memory and isn't forgotten for a long time if the information is read several times over. For example, we assume that we memorize a telephone number when we listen and never remind we may forget it soon, but we commit to memory long time by repeating. If the human being received new information with strong stimulus, it could remain in memory without recalling repeatedly. The moments of almost losing one's life in on accident or getting a stroke of luck are rarely forgiven. The human being can keep memory for a long time in spite of the limit of memory for the mechanism mentioned above. In this paper, we will make a model explaining that mechanism using a neural network Adaptive Resonance Theory.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.362-364
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• 2009

Most of electrical installation and construction specifications consist of many letters as non-visual format. Therefore writing specification for installation and construction is so difficult to make easier to user. And it could not be an effective work to make a specification and make an accident or disabled facilities and equipments. Hence we need to develop the program that makes a specification of electrical installation and construction due to need a safety and coherence.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.6-9
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• 2009

Recently, there have been studied the importance of the grounding system, as electrical equipments installed in the building, such as intelligent building. The object of grounding of electrical facilities is to protect human and machine damage from the power supply interruption high voltage by use of the accident current dissipating into the ground. In this paper, we is proposed to design of grounding system with economical efficiency in electric rolling stocks facilities. To make efficient ground, ground potential rise must be controlled in the way of overall lowering and evenness instead of independent grounding method with respect to electrical facilities.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2305-2306
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• 2008

Charging of spacecraft occurs in plasma and radiation environment. Especially, we focused on an accident caused by internal charging in a glass material that was used as the cover plate of solar panel array, and tried to measure the charge distribution in glass materials under electron beam irradiation by using a PEA (Pulsed Electro-Acoustic method) system. In the case of a quartz glass (pure $SiO_2$), no charge accumulation was observed either during or after the electron beam irradiation. On the contrary, positive charge accumulation was observed in glass samples containing metal-oxide components. It is found that the polarity of the observed charges depends on the contents of the impurities. To identify which impurity dominates the polarity of the accumulated charge, we measured charge distributions in several glass materials containing various metal-oxide components and calculated the trap energy depths from the charge decay characteristics of all glass samples.