• 청정기술
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• 제27권2호
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• pp.160-167
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• 2021

본 연구에서는 시화반월산업단지에서 보편적으로 사용하고 있는 일반형 활성탄흡착탑과 활성탄 공동재생시스템 적용을 위해 개발된 카트리지형 활성탄흡착탑으로 개선하여 얻게 되는 환경적 효과분석을 고찰하였다. 일반형 활성탄흡착탑 4개소와 카트리지형 활성탄흡착탑 2개소를 선정하여 사용하고 있는 활성탄의 물성특성을 분석하고 환경오염물질의 저감효율을 비교 분석하였다. 그 결과, 카트리지형 활성탄 흡착탑에 사용되는 활성탄은 요오드흡착력 800 mg g^-1 이상의 양질의 활성탄으로 확인되었으며 교체주기내에서 양호한 수준으로 활성탄 흡착성능이 유지되는 것으로 확인되었다. 환경오염물질 저검효율 분석결과 카트리지형 활성탄 흡착탑의 경우 THC (Total Hydrocarbon), toluene 및 MEK (Methylethylketone) 성분의 처리효율이 각각 71%, 77% 및 80%로 좋은 처리효율을 보인 것으로 확인되었다. 일반형 활성탄 흡착탑은 처리효율이 매우 낮아 배출오염물질을 처리하는 방지시설로서의 역할을 제대로 하지 못하고 있었다. 일반형 활성탄 흡착탑을 카트리지형 활성탄 흡착탑으로 개선하여 운영 시 배출오염물질을 저감시킬 수 있을 것으로 판단된다.

• 대한안전경영과학회지
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• 제18권3호
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• pp.33-45
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• 2016

Construction sites have gradually become bigger and bigger according to Korea economic growth. Also use of tower crane and other heavy equipment has been increased. The increased use of heavy equipment like tower crane is leading to fatality incident. This study will verify hazards to influence tower crane incident through structural and positive verification and find which hazard influence incident risk. The result of this study is as follows. First, while there is a significant difference between safety managers and tower crane operators for working environment, safety management, personal manage among risk factors, we can not find any evidence on the difference in perception of tower crane incident risk between them. Second, task manage risk and personal manage risk has a significant positive effect on perception of tower crane incident risk. Third, while site environment risk has a significant positive moderating effect of task type between risk factors and perception of tower crane incident risk, personal environment risk has a significant negative moderating effect between them.

• 설비공학논문집
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• 제22권1호
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• pp.20-25
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• 2010

In this study, As a basic research for improving indoor thermal environment at tower type apartment houses, specifications of heat storage and heat emission in the structures of apartment houses were investigated, and the ratio of indoor and outdoor air velocity at tower type apartment house was examined, too. Indoor temperature at night time was higher than outdoor air temperature because heat emission from the structure of wall, ceiling and floor those are constructed by use of reinforced concrete which has large heat capacity. The ratio of indoor and outdoor air velocity was lower than 0.1 and this was caused by the plan of tower type apartment house. PMV was in the range of 0.3~1.9, and was about 1.0 (it means slightly warm) at 10 : 00 p.m.. To improve indoor thermal environment in summer season at tower type apartment houses, it needs more investigation on specifications of heat storage and heat emission in the structure including winter season, and on the improvement of the ratio of indoor and outdoor air velocity.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.341-342
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• 2006

This study is concerned about the development of tower type automatic tool changer. The tower type automatic tool changer is developed to reduce stand-by time by shortening tool change time. The developed system can store more number of tools in small space. A structural analysis for the machine is carried out to check the machine design using commercial software, CATIA V5. In the result of structural analysis, the safety of the developed system is confirmed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.185.2-185.2
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• 2010

With the development of wind industry, the rated power of wind turbine also increase gradually. Accordingly, the size of wind turbine tower becomes larger and larger. The tower base diameter of 2MW wind turbine is about 4m. Larger tower is expected for 4MW or 5MW turbine. Due to limitation of transportation, new type of tower with smooth transportation and effective cost is needed. In this work, a hybrid tower consisting of steel and concrete is designed and analyzed. The optimum ratio of steel and concrete of hybrid tower are calculated as well as the thickness of the concrete part. Different FE analysis including modal analysis, buckling analysis and fatigue analysis are performed to check the design of hybrid tower comparing with the steel tower. Redesign is also expected after various analysis.

• 한국소음진동공학회논문집
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• 제17권7호
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• pp.649-661
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• 2007

Friction-type reinforcing members(FRM) to enhance the resistance to wind loads of a transmission tower through both stiffness strengthening and damping increase are energy dissipation devices that utilize bending deflection of a tower leg. In this paper, the hysteretic behavior of the transmission tower structure with FRMs was experimentally investigated through cyclic loading tests on a half scale substructure model. Firstly, the variation of friction forces and durability of the FRM depending on the type of friction-inducing materials used in the FRM were examined by performing the cyclic loading tests on the FRM. Secondly, cyclic loading tests of a half-scale two-dimensional substructure model of a transmission tower with FRMs were conducted. Test results show that the FRM, of which desired maximum friction force is easily regulated by adjusting the amplitude of the torque applied to the bolts, have stable hysteretic behaviors and it is found that there exists the optimum torque depending on a design load by investigating the amount of energy dissipation of the FRMs according to the increase of torque.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.568-577
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• 2007

Friction-type reinforcing members (FRM) to enhance the resistance to wind loads of a transmission tower through both stiffness strengthening and damping increase are energy dissipation devices that utilize bending deflection of a tower leg. In this paper, the hysteretic behavior of the transmission tower structure with FRMs was experimentally investigated through cyclic loading tests on a half scale substructure model. Firstly, the variation of friction forces and durability of the FRM depending on the type of Friction-inducing materials used in the FRM were examined by performing the cyclic loading tests on the FRM. Secondly, Cyclic loading tests of a half-scale two-dimensional substructure model of a transmission tower with FRMs were conducted. Test results show that the FRM, of which desired maximum friction force is easily regulated by adjusting the amplitude of the torque applied to the bolts, have stable hysteretic behaviors and it is found that there exists the optimum torque depending on a design load by investigating the amount of energy dissipation of the FRMs according to the increase of torque.

• Structural Engineering and Mechanics
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• 제81권2호
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• pp.147-161
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• 2022

The Brace-Type Shear Fuse (BSF) device is a newly proposed steel damper with excellent cumulative ductility and stable energy dissipation. In consideration of the current situation where there are not many alternatives for transversal seismic devices used in long-span three-tower self-anchored bridges (TSSBs), this paper implements improved BSFs into the world's longest TSSB, named Jinan Fenghuang Yellow River Bridge. The new details of the BSF are developed for the TSSB, and the force-displacement hysteretic curves of the BSFs are obtained using finite element (FE) simulations. A three-dimensional refined finite element model for the research TSSB was established in SAP2000, and the effects of BSFs on dynamic characteristics and seismic response of the TSSB under different site conditions were investigated by the numerical simulation method. The results show that remarkable controlling effects of BSFs on seismic response of TSSBs under different site conditions were obtained. Compared with the case without BSFs, the TSSB installed with BSFs has mitigation ratios of the tower top displacement, lateral girder displacement, tower bending moment and tower shear force exceeding 95%, 78%, 330% and 346%, respectively. Meanwhile, BSFs have a sufficient restoring force mechanism with a minor post-earthquake residual displacement. The proposed BSFs exhibit good application prospects in long-span TSSBs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1726-1735
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• 2008

Seoulmetro has operated the air cooling equipment for 57 stations to improve services focused on our customers who use Seoulmetro during the summer season and has established every year. However, a new set of problems has arisen with the cooling tower to support a heat exchange of cooling water. The most important matter is loss of efficiency in the cooling tower. The leading cause of this problem is that we use an indoor type. As the cooling tower room is located in the underground of the city because of the residents near the station. Therefore It is difficult to establish the cooling tower on the ground. But it is unsuitable for the location requirements of the underground type because it has a limited space to set up the air cooling equipment, for example, the cooling tower and a ventilating opening. As a result of such an unfavorable condition, the cooling tower doesn't work efficiently and the warmth of cooling water because of insufficiency of a heat exchange and a refrigerator's technical obstacle such as a high-temperature and a high-pressure has arisen. To prevent this situation, the operator tend to reduce refrigerant. Accordingly, the efficiency of the air conditioning is getting lower and lower. Study wishes to analyze the matter to improve indoor cooling tower efficiency and recommend a best practice for a person who manage the establishment.

• 한국대기환경학회지
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• 제26권3호
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• pp.339-345
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• 2010

There have been a number of efforts to satisfy national emission regulations and reduce the amount of emitted air pollutants. There are several air pollution control devices, however, only wet scrubber is efficiently used to remove particulate matters and gaseous pollutants, even if it has minimum collection efficiency in the particle size range of $0.1{\sim}1{\mu}m$. This study aimed to improve the collection efficiency of a spray tower type scrubber by introducing an electrospray system with two-flow nozzle. We found that the collection efficiency of a spray tower type scrubber was similar to that of a conventional wet scrubber. However, installation of an electrospray system in the scrubber resulted in drastic further improvement of collection efficiency comparing to that of a conventional scrubber, which is 26%, 35.2%, and 45.1% at the liquid to gas ratio of 0.26 $L/m^3$ and 19.9%, 35.1%, and 42.5% at 0.34 $L/m^3$ for the applied voltage of -30 kV, -35 kV, and -40 kV, respectively. Therefore, we found that the introduction of an electrospray system is very effective to improve the collection efficiency of a spray tower type scrubber.