• Membrane Journal
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• v.25 no.2
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• pp.99-106
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• 2015

Polysulfone (PSF) hollow fiber membrane was prepared to separate $CO_2$ from the flaring gas. Fabricated PSF membrane system was fulfilled under 1 stage, 2 stage membrane process and simulation in order to confirm the operating condition for 99% of $CH_4$ and 1% of $CO_2$ concentration. Also, $25Nm^3/h$ bench scale $CO_2$ separation membrane system was operated under 1% of $CO_2$ concentration during 100 hr, and $CH_4$ recovery ratio was 98%.

• Resources Recycling
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• v.14 no.5 s.67
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• pp.54-61
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• 2005

In 2006, the coal usage that is used as energy source of power plant will meet 16,000 MW which is 30% of the whole energy usage. A Coal deposits among the fossil fuels is very plentiful in natural resources and has high economical efficiency but application technique is very inconvenient. Also when burned for utilization, it generate various toxic and untoxic air pollution materials; fly ash, bottom ash, sulfurous acid gas etc. In this study, we could establish a preparation of clean coal by triboelectrostatic separation. In this study, we made a bench-scale's triboelectrostatic separation equipment using electrostatic technology, and got an optimum conditions of various factors for increasing recovery rate and purification in separation. A test result, we got a clean coal that recovery rate is 68.10%, rejection rate of ash and sulfur content is 31.23% and 28.33%.

• Journal of Environmental Health Sciences
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• v.28 no.5
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• pp.42-52
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• 2002

Two full-scale distribution systems, one treating water by ozonation and another treating water by nanofiltration in parallel with lime softening, were monitored for bacterial growth. Both systems kept disinfectant residuals surf as chlorine and chloramine in their respective distribution systems. Bacterial growth was assessed by heterotrophic plate counts (HPC) on R2A agar. In the distribution systems fed by ozonated water, HPCs were correlated ($R^2$= 0.97) using an exponential model with the assimilable organic carbon (AOC) at each sampling site. Also, it was observed that ozonation caused a significant increase in the AOC concentration of the distribution system (over 100％ increase) as well as a significant increase in the bacterial counts of the distribution system (average increase over 100％). The HPCs from the distribution systems fed by nanofiltration in parallel with lime-softening water also displayed an exponential correlation ($R^2$ = 0.75) with an exponential model based on AOC. No significant correlation was found between bacteria growth on R2A agar and BDOC concentrations. Therefore, in agreement with previous work, bacterial growth in the distribution systems was found to correlate with AOC concentrations.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.4
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• pp.266-273
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• 2003

The purpose of this study is to obtain the effects of the parameters of the suspension system in railway rolling-stock for KT-23 type Passenger vehicle. According to the analysis and the small scale model car test. optimal condition was obtained for the stiffness ratio of secondary spring to primary spring of the suspension system and the mass ratio of the bogie frame to the car body. The analysis of the study shows that if the car body mass is increased or secondary stiffness Is lowered, the vertical vibration level is reduced and the passenger comfort can be improved. Especially, strong peaks are occurred in the frequencies corresponding to the rotational speed of driving axle and vehicle wheel. Hence, in order to obtain the dynamic characteristics through the small scale model car, the driving method of the vehicle on the test bench, rotational characteristics of the wheel and the natural modes of vehicle should be investigated and be modified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.139-142
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• 2008

While a lot of comparisons of DBMS performance for processing large scale database are given as results of bench-mark tests, there are few comparisons of DBMS performance for processing small scale database. Therefore, in this study, we compared and analyzed on the performance of commercial DBMS and public DBMS for small scale database. Analysis results show that while Oracle has low performance on the operations of update and insert due to the overhead of rollback for data safety, MySQL and MS-SQL have good performance without additional overhead.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1999-2004
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• 2008

While a lot of comparisons of DBMS performance for processing large scale database are given as results of bench-mark tests, there are few comparisons of DBMS performance for processing small scale database. Therefore, in this study, we compared and analyzed on the performance of commercial DBMS and public DBMS for small scale database. Analysis results show that while Oracle has low performance on the operations of update and insert due to the overhead of rollback for data safely, MySQL and MS-SOL have good performance without additional overhead.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.235-238
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• 2002

폐기물을 처리대상으로 하는 가스화용융공정은 환경문제와 에너지효율 문제를 동시에 접근할 수 있는 공정으로서 향후 연소반응에 근거한 공정을 점진적으로 대체할 것으로 예측되고 있다. 본 센터에서는 "가연성 폐기물처리용 5톤/일급 가스화용융 공정기술개발"의 과제를 과학기술부 국가지정연구실사업을 통해 수행 중에 있으며, 1톤/일급 가스화 용융로의 설계/운전, 폐기물별 가스화용융특성 Database화, 5톤/일급 scale-up 설계 등을 주요 연구목표로 폐기물의 가스화용융기술을 개발 중에 있다.(중략)

• Journal of Korean Society of Water and Wastewater
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• v.7 no.2
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• pp.1-8
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• 1993

Constant rate permeat experiments using polyethylene hollow fiber membranes were conducted in order to treat dam water for potable purposes. The experiments consisted of two series. One series consisted of six bench scale apparatuses, each having a $0.4m^2$ nominal permeat area, which were applied in determining the optimum operating conditions. The other series was comprised of two pilot scale plant, each having a $40m^2$ nominal permeat area. Both series were operated for six months. Coagulant was not used in any of the experiments. To suppress an increase in differential pressure between the inlet and outlet of the membrane, a hydrophilic membrane was found to be better than a hydrophobic membrane. Also, permeat flux should not be more than 0.03m/h, and air bubbling-washing for 1 minute should be conducted at 180 minutes intervals or less.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.127-132
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• 2002

Numerical and experimental works have been made in order to figure out the physical mechanism of thermal storage system for the determination of optimal design and to enhance the thermal efficiency of the system. To this end a computer program is developed and evaluated successfully against experimental data measured with a bench scale facility. Considering the thermal efficiency of storage is critically impaired by the mixing effect, the minimum flow mixing situation is calculated by the assumption of uniform plug-type flow as a reference condition. Further a parametric systematic calculations have been made for a hypothetical full-scale storage system with Fr, storage dimension, diffuser type and loading hour, etc.

• Fire Protection Technology
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• s.19
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• pp.22-28
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• 1995

The rate of heat release is probably the single most important measure of fire hazard. Several tech-niques were developed for the measurement of rate of heat release, but were not suitable for fire test-ing purpose. Recently the application of oxygen consumption principle made it possible to development of well-characterized heat release rate measurement apparatus, the furniture calorimeter for large-scale fire tests and the cone calorimeter for bench-scale fire tests. The cone calorimeter can be used to determine the ignitability as well as heat release rate and smoke development, mass loss rate, combustion gas production etc. from burning materials. Thus, test method using cone calorimeter, an internationally recognized and accepted for the evalua-tion of fire properties, is a very promising tool for combustion study on various kind of materials and products.