• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.4
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• pp.325-332
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• 2011

This paper is concerned with the active control experiments on elevator vibrations by means of the active roller guide. To this end, a roller guide was designed using a voice-coil actuator and linear guide. A simple proportional control algorithm combined with the band-pass filter was implemented using the DSP. Based on the initial experiments, a new control system which can handle lateral and front-back vibrations of elevator was built and tested using the elevator test tower. The experimental results show that the elevator vibrations are reduced by the active control technique.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.1023-1028
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• 2003

The structure of Tower Palace III Sports Center building was designed as concrete Filled Steel Tube(CFT) Column and the filled-in concrete was designed as high compressive strength of 500kgf/$m_2$. The self compacting concrete(SCC, non-vibrating concrete) with 65$\pm$5cm flow must be applied to this case for filling the CFT by injecting the concrete from the column bottom. Laboratory tests and pilot productions of batcher plant were performed for optimum mix design and the full scale Mock-Up test was performed to check the appicability of the construction method. As a result, we observed that good quality SCC and the pressure change of concrete pump normally used domestically. Based on these results, we have constructed 20-40m height CFT columns successfully.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.35-37
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• 2002

Most of the inhabitants living near power line complain wind noise from power line to be problems they can feel directly if there is no countermeasure to remove noise basically. Wind noise from power line happens by tower, insulators, conductor and others in their operating individually or complexly. Wind noise show us several forms like whistle, siren and bullfrog croaking as height of noise source is high and elastic wave tone with low frequency. This paper shows actual conditions and occurrence cause which may be investigated and analyzed on the wind noise, and also prepares mitigation methods and introduces a working sample to reduce a wind noise.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.455-459
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• 1999

용접열영향부는 최고 도달온도로부터의 거리에 따른 온도구배 변화와 급격한 열 사이 클 때문에 조직 및 물성치의 변화가 예상되는 영역이므로 인성저하등 취성이 잠재적으로 내포된 지역임을 쉽게 예상할 수 있다. 따라서 송전 철탑용 STKT 590 용접열영향부에서의 상변태 거동과 미세조직의 변화에 따른 기계적 특성을 파악하여 용접부의 안전성 확보를 위해 용접열영향부(HAZ)의 상변태거동과 미시파괴기구를 연구하고 개선안을 도출할 필요가 있다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.79-80
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• 2002

지난 수 십여년에 걸쳐 대기질 관리를 위해 시도된 범국가적 또는 범국제적 차원의 노력에 힘입어, 일반적으로 대기질을 평가하는 보편적인 지표로 간주되는 기준성 오염물질들의 계량적인 수치자료들은 괄목할 만한 개선효과를 확인시켜 주고 있다. 특히 기기적으로 검출한계 이하의 관측자료가 양산되는 이산화황 (SO$_2$) 또는 규제기준에 접근하기 어려울 정도로 낮은 농도에서 관측되는 납 (Pb) 성분 등의 시간적 저감양상은 이러한 노력의 큰 결실로 지목할 수 있다. 이와 같은 대기질 개선의 노력에도 불구하고, 아직까지 많은 사람들이 체감하는 대기질에 대한 평가는 상당 수준 부정적으로 남아 있다. (중략)

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04a
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• pp.111-130
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• 1997

The lack of water resources is becoming worse due to water pollution with accelerated industrialzation and regional unbalanced distribution of water resources. In recent, the production water quality is decreasing because of the increased organic matters and soluble solids in the water sources for power plants. The purpose of this paper discribes the ststus and prospect of membrane application in electric power industry. So this study lies in developing a process which can produce high purity water by appluing RO(Reserve Osmosis) ahead of the IX(Ion Exchange) tower and evaluating the product water quality and the cost effectiveness. The capital and operating cost for the treatment of brackish water, sea water by RO were presented as a reference for the review on securing water source for the new plant site.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.7
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• pp.832-838
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• 1999

Recently, there are growing concerns about power frequency electric and magnetic fields coming out from the high voltage transmission lines, because of the wide spread perception of their probable harmful effect on human body. In connection with this trend, this paper describes the electric and magnetic fields measurement result around 154 kV and 345 kV transmission lines, a comparison of measured EMF to calculated one and the correlations between transmission lines currents and measured magnetic fields. Daily maximum and minimum magnetic field quantities under the selected 154 kV and 345 kV transmission lines had been measured for 1 year of 1997 and the average value of magnetic field exposure under the lines were calculated and presented based on the measured data.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2280-2283
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• 1999

Close to high power radio/radar transmitters, there is a possibility that electrical sparks may occur at discontinuities in metallic structures. If these structures are in an area where flammable mixtures are present, there is a danger that fire or explosion may happen by these sparks. Voltage may be induced on these metallic structures by the radio-frequency transmitter. In this case, a person who comes into contact with these structure may be undergone a severe electrical shock. In this paper, assessment of the these hazards was investigated through experimental and evaluation for actual tower cranes near AM radio transmitters.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.99-107
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• 2004

Likelihood of failure (LOF) for the external corrosion of stainless steel, which affect to a risk of facilities, was analyzed quantitatively through the risk based inspection using API-581 BRD. We found that the technical module subfactor (TMSF) decreased as the inspection number increased and it increased as the inspection effectiveness and the used year increased, and that the TMSF showed high value for the case of the marine/cooling tower drift area as a corrosion driver, In this condition, the LOF for the external corrosion of stainless steel had lower than that for the carbon and low alloy steels

• Journal of the Korea Safety Management & Science
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• v.6 no.4
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• pp.239-248
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• 2004

Likelihood of failure for the external corrosion of carbon and low alloy steels, which affect to a risk of facilities, was analyzed quantitatively through the risk based inspection using API-581 BRD. We found that the technical module subfactor (TMSF) decreased as the inspection number increased and it increased as the Inspection effectiveness and the used year increased. In this condition, the TMSF showed high value for the case of the marine/cooling tower drift area as a corrosion driver, poor quality of coating, no insulation, and low insulation condition.