• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.48-50
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• 2001

Recently, electric heating using midnight power has brought a rapid increase. due to a rise of oil price and a low tariff of midnight power. Therefore, the increase of midnight power use has much influenced on midnight load pattern. This paper estimates the load pattern due to midnight power equipments, analyzes the influence of the spread of midnight power equipments on midnight load and suggests reasonable spread level of equipments.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.516-518
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• 1995

This paper presents the optimal short-term operation scheduling by using fuzzy linear programming method on cogeneration systems connected with auxiliary equipments. Simulation is performed in case of the bottomming cycle. Modeling of cogeneration systems and auxiliary equipments is done, the effectiveness of modeling is evaluated through the detailed simulation. After the optimal operation scheduling is established by using linear programming method, the last optimal operation scheduling is established by using fuzzy linear programming method. The results of simulation show the auxiliary equipments can be effeciently operated in case of the bottomming cycle by modeling proposed in this paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.798-806
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• 2001

As electronic industry and radio communication technologies progress, the electrical and electronic equipments are lightened, minimized, and operated by low power. At the same time, these equipments react sensitively by electromagnetic wave noise. It is a origine these equipments to wrong-operation. In this paper, we focused on the design and preperation condition of a advanced EMI filter. This filter sowed superior attenuation effect of 10 dB~20 dB compare with typical filter in the range of frequency from 150 kHz to 30 GHz and superior character over the variation of a load.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.102-104
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• 2004

Finger language is a typical tool for deaf persons. But learning the finger language for non-handicapped persons is very difficult. To overcome these difficulties, a new communication method using visual function is developed recently. Even though the developed system uses the visual function, it needs expensive equipments such as camera and computer. To be used in the real environments, the cost of equipments is a critical factor. If the recognition system for the finger language can be developed with low price equipments, the system can be used in the notebook or cellular phone. The image captured by PC camera was processed by preprocessing algorithm. To recognize the finger language, the resulting image was divide into $5{\times}5$ sections. The recognition system uses a similarity method and position information. The simulation results shows the effectiveness of the proposed algorithm.

• Proceedings of the KIEE Conference
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• 2006.05a
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• pp.12-16
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• 2006

현대사회의 빠른 변화는 서비스 업종 분야에서도 일어나고 있으며 다중이용업소의 종류뿐만이 아니라 내부에 시설되는 전기설비 또한 다양화 되고 있다. 본 논문에서는 신종다중이용업소의 전기설비에 대하여 실시된 현장실태조사 결과를 분석하여 문제점을 도출하고 개선방안을 제시하고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.269-273
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• 2013

This paper analyzed a potential interference of electric equipments on radio service below 30MHz through an experiment with a PDP(Plasma Display Panel) TV and a RF(Radio Frequency) light bulb in an anechoic chamber. The radiation levels of the PDP TV and the RF light bulb are measured and a combined interference is calculated on the basis of the experimental value. As a result, the combined interference signal level is increased according to the number of interferer. The possibility of a potential interference from electric equipments on radio service below 30MHz is realized through comparison between the measured radiation value of electric equipments and the CISPR(International Special Committee on Radio Interference) 11 limit.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.208-213
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• 2008

In recent society, the quality of human life has improved due to the use of electric appliances and the high powered electrical equipments. However, lots of electric appliances and equipments generate the electromagnetic field hazard. Many studies have been made about the wrong behavior of machines due to electromagnetic fields, the interferences in communication equipments, the possibility of the electromagnetic field hazard in human body, etc. There exist international standards about the RF equipments (ex. mobile phone, antenna, etc.). But, many researchers involved in power frequency electric and magnetic field only propose the prudential avoidance. In this paper, induced currents in a human body model due to magnetic fields in high speed railway are calculated by two dimensional impedance method. Power frequency(60Hz) magnetic fields are calculated and induced currents are simulated by Faraday's law. Induced currents are simulated with induced voltage, human body model impedances due to Ohm's law, magnetic fields derived from Biot-Savart's law and Transmission Line Method in high speed railway.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.273-280
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• 1997

Recently the importance of the cargo handling equipments in a port has been increasing to get strong competition from other ports. Many ports are making efforts to modernize their cargo handling equipments. The kernel technology of such equipments is the speed control of DC motor which is used as an essential part of them. In this paper, we discuss the speed control of a DC motor as a basic work for building cargo handling equipments in a port. DC Motors are still widely used in industrial fields, as driving power motor for electrical fields. DC drives, being easy to control, are widely used in many variable-speed and position control drive system. Traditional analog control circuits used in such applications have many disadvantages. Complex control schemes are difficult to implement with analog components. All these factor and invention of the microprocessor has made it possible to use digital control circuits, using microprocessing system. These digital circuits have been found to be reliable, flexible, and also immune to noise. In this paper it presents the speed control of a SCR DC motor driver which using dual converter by 80c196kc microprocessor. We developed a thyristor power amplifier which does not cause damage thyristor because it is designed to prevent triggering the two SCRs in the same arm simultaneously. And it was analyzed voltage and currents wave at reactive load.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.103-108
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• 2007

Eurostar 3000 AOCS is optimized for telecommunication mission with no strong requirement on attitude stability and has therefore to be upgraded to comply with COMS high stability requirements for the optical observations. This COMS configuration constraint induces specificities for the wheel. The aim of this analysis is to verify the electrical compatibility of the interfaces which exist between COMS wheels and external equipments. For each interface, this study checked the compatibility between equipments for the power links, commands, digital telemetry, analog telemetry, and failure condition or AIT errors. In addition with this interface compatibility verification, this study outputs electrical and manufacturing recommendations to be applied at harness level.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.196-197
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• 2006

Preventive maintenance can avail the generation utilities to reduce cost and gain more profit in a competitive supply-side power market. So, it is necessary to perform reliability analysis on the systems in which reliability is essential. In this paper, RCM (Reliability -Centered Maintenance) analytical method is adopted using real historical failure data in Korean power plants. Therefore, the reliability -based Probability model for predicting the failures of components in the power plant is also established, and application to FMECA(Failure Mode Effects and Critical Analysis) consideration of failure probability, Based on the weighting ranking of generating equipments which status to be probability estimation by FMECA. The FMECA is an engineering analysis and a core activity performed by reliability engineers to review the effects of probable failure modes of generating equipments and assemblies of the power system on system performance. The results of this paper show that application of FMECA with stochastic approach to the preventive maintenance can efficiently avail decreasing the cost on maintenance and hence improve the total benefit.