• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.804-807
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• 2007

The acid gas removal (AGR) system was designed and installed to remove $H_2S$ in coal syngas in the pilot-scale coal gasification system for producing chemicals like Dimethyl Ether(DME). The syngas from the coal gasification at the rate of $100{\sim120$ $Nm^3$/hr included pollutants such as fly ash. $H_2S$, COS, $NH_3$, etc. The designed temperature and pressure of the AGR system are below 50oC and 8 kg/$cm^2$. Fe-chelate was used as an absorbent. $H_2S$ was stably removed below 0.5 ppm in the AGR system when the concentration of $H_2S$ was $150{\sim}450$ ppm. The pH of Fe-chelate solution was also stably maintained between $8{\sim}9$. FeMgO absorbent was also tested to remove $H_2S$ in the lab-scale AGR system and $H_2S$ was also removed below 0.5 ppm in the initial operation.

• Korean Journal of Crystallography
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• v.2 no.1
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• pp.23-26
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• 1991

Amethysts were grown hydrothemally. The origin of amethyst color is iron center, which is developed by correlation between Fe3+(substitutional) and Fe3+ (interstitial)1). Crackless amethysts without smoky centers were grown only from major (1011) and minor (1101) seeds on K2c03 solutions. The violet color of amethyst depended on both iron concentration and amount of irradiation of r-ray. Increasing the iron concentration resulted in the deep violet color. Also amethysts color were changed to dark proportional to amount of irradiation. From visible spectra it was found that increasing the amount of irradiation affected not the character of individual iron center but the total number of iron centers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.932-937
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• 2008

The transformer inrush current can cause a voltage drop by source impedance. This current can impact sensitive loads by the voltage drop. Therefore, it is necessary to take measures to limit this inrush current. This study, described in this paper, analyzes the power quality affected by transformer inrush current using the X power system in Korea. The Electromagnetic Transients Program(EMTP) is used to analyze the transient phenomenon. We discuss a method to model the hysteresis curve of the transformer in EMTP. We carried out various simulations to analyze the power quality during transformer energization. The analysis results of voltage drop by the inrush current occurrence when certain requirements are met are presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.25-27
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• 2010

국제해사기구(IMO) 제52차 NAV 회의에서 처음 소개된 e-Navigation은 그동안 국제항로표지협회(IALA), 국제수로기구(IHO), 국제통신연맹(ITU) 및 국제전기표준위원회(IEC)에서 많은 정책과 기술사항이 검토되어 왔다. 본 논문에서는 IALA e-NAV 제8차 기술위원회('10.9.20-24)에 참석하여 관련 국제기구에서 진행중인 e-Navigation 추진현황과 동향을 파악하여 앞으로 우리나라의 대응방향을 논하고자 한다.

• Korean Journal of Optics and Photonics
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• v.8 no.4
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• pp.297-302
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• 1997

A hemiconfocal resonator equipped with an intra-cavity adjustable aperture and a beam splitter has been studied experimentally to achieve a controlled low beam divergence operation in a vapor laser system. The dependences of output characteristics both on the aperture diameter and on the angle of beam splitter have been investigated. By adjusting the aperture diameter from 14mm to 2mm to 2mm, we were able to reduce the beam divergence from 3.1 mrad to 0.25 mrad and achieved the 8-times increase in the far-field power density.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.474-479
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• 1998

In this paper, the structural behavior of R.C. multi-layered floor structure including foam concrete layer is numerically analyzed. For the analysis, 3D interface element has been implemented to finite element analysis program to consider the interfacial behavior of multi-layered floor structure which consists of rubber layer, foam concrete layer and mortar layer on RC slab. Based on analysis results on multi-layered structure, its structural behavior is analyzed according to geometrical and material properties of foam concrete. Optimum material property of each layer of the floor structure is proposed to get optimum multi-layered concrete structure.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.320-325
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• 1999

세계기후협약으로 인하여 우리나라는 화석연료 사용량을 최소한 2010년까지 2000년 수준으로 감축시켜야할 처지에 놓여 있다. 따라서 지구 온난화의 주 요인이 되고 있는 이산화탄소 배출량을 2010년 예상배출량의 21%정도를 감축해야 하며, 경제활동은 1/4이상이 축소되는 영향을 받게 된다(차재호, 1998). 따라서 현재의 화석에너지에 의존하는 난방법은 자연에너지 또는 전기에너지 등으로 대부분이 전환되어야 할 것으로 전망하고 있다 그러나 농업에 이용되고 있는 난방에너지는 화석에너지에 집중되어 있으며, 온실, 축사, 버섯재배사 등에서 겨울철 난방에 소요되는 에너지 비용은 총경영비의 10-40%를 차지하고 있다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.52-58
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• 2001

우리나라의 시설농업은 겨울철 난방에 소요되는 에너지원의 대부분을 수입에 의존하는 화석에너지를 이용하고 있다. 따라서 생산비중 난방비의 비중이 국제원유가의 상승에 비례하여 증가하므로서 농산물의 가격이 불안정하며, 결국에는 재배농민의 생산욕구를 저하시켜 농가소득의 감소를 초래하고 있는 실정이다. (중략)

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.859-864
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• 2001

An effective live load model for analyzing probable maximum live load effects such as moment and shear in transverse direction was developed. The main procedure of this live load model is composed of four parts, i.e., firstly, determination of the appropriate influence lines in longitudinal direction, secondly, application of the characteristics of vehicles and traffic patterns in longitudinal direction, thirdly, determination of the appropriate influence lines in transverse direction, and fourthly, application of the characteristics of vehicles and traffic patterns in transverse direction. Through this procedure, the probabilistic distributions of maximum probable load effects are deduced in the form of probability density function (PDF) and/or cumulative density function(CDF). This live load model is able to consider local or global deterioration of bridges in the structural analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.865-870
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• 2001

An effective live load model for analyzing probable maximum live load effects in longitudinal direction such as moment and shear was developed. The main procedure of this live load model is composed of two parts. Firstly, determination of the appropriate influence lines, and secondly, application of the characteristics of vehicles and traffic patterns. Through this procedure, probabilistic distributions of maximum probable load effects are deduced in the form of probability density function (PDF) or cumulative density function (CDF). The proposed live load model is not limited by bridge types(number of spans or girders) and can consider local or global deterioration of bridges in the analysis. Besides, load effects can be determined at any section without restrictions.