• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.227-233
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• 2008

Porous concrete has large continuous voids of 20-30 % by volume, and this concrete is attractive as environmental material in Japan i.e. permeable road pavement, river bank protection with vegetation and green roof system which influence thermal environment. It is necessary to confirm the frost resistance when constructing porous concrete structure in cold region. However applicable test method and evaluation criterion of porous concrete has not defined yet. Therefore, the object of this study is to investigate the frost resistance of porous concrete and this investigation attempts to address this concern by comparing 4 kinds of specified freezing and thawing tests methods (JIS A1148 procedure A/B and RILEM CIF/CDF test) in consideration of actual environment. RILEM freeze-thaw tests are different from JIS A1148 freeze-thaw tests, which are widely adopted for evaluating the frost resistance of conventional concrete in Japan, in water absorption, cooling rate, length of freezing and thawing period, and number of freezing and thawing cycles. RILEM CIF test measures internal damage and is primarily applicable for pure frost attack. CDF test is appropriate for freeze-thaw and de-icing salt attack. JIS A1148 procedure A/B showed extremely low frost resistance of porous concrete if the large continuous voids were filled with water and the ice expansion in the large continuous voids set in during cooling. Frost resistance of porous concrete was improved by mixing coarse aggregate (G7) which particle size is smaller and fine aggregate in JIS freezing and thawing tests. RILEM CIF/CDF test showed that freeze-thaw and de-icing resistance of porous concrete was seems to be superior in that of conventional concrete.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.784-793
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• 2006

As the number of CFRD constructions increases, the necessity of an accurate assessment on its behavior also has been increasing accordingly. The performance of concrete faced rockfill dam (CFRD) under different water levels is greatly concerned by dam engineers and designers in the world. However, domestic research on CFRD design and construction has yet been insignificant. This study deals with three centrifuge model tests, mainly investigates the deformation of the concrete faced slabs with different face slab stiffness under different water levels. The prototype of a centrifugal model dam is half size of domestic CFRD dam. Detailed material preparation, model design, model set-up, model instrumentation and testing procedures are presented. In order to simulate the prototype concrete faced slab, three kinds of thin fiberglass plates with different thickness was adopted in the three model tests. The water level control facility was specially designed for this experiment to control the water level rise and drawdown during centrifuge flight. Although most of the results from the three model tests are satisfactory, it is also required that the centrifuge test results should be compared with those of numerical analysis and field measurements to analyze the centrifuge test results more in detail.

• 생태와환경
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• 제40권4호
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• pp.560-568
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• 2007

The objectives of this study were to analyze ecological effects on effluents from the Sagok Stream (Chonnam province) as an abandoned mine drainage through necropsy-based health assessments and fish exposure tests, and to conduct In situ field pilot tests for restoration of stream water. Also, we analyzed water quality including general parameters and heavy metals. The tests were performed three times on April 2005, April 2006, and April 2007. Also, we constructed a reactor facility in the outflowing point of the abandoned mine for the remediation of AMD wastewater. In lab test, death rates in all three treatments were ${\geq}50%$ in the experiments. Necropsybased fish tissue assessments using the Health Assessment Index (HAI), indicated that the most frequently damaged tissue was liver (average: 20.8). Values of Health Assessment Index were lower in the control than any other treatments of T1, T2, and T3 and three treatments showed a distinct toxicity impacts by the AMD. In situ lethal test, concentration of Fe, Al and Zn decreased particularly by 85%, 99% and 94%, respectively through the disposal facility. Values of pH, ranged from 3.1 to 7.0, increased by 2.3 fold (mean=5.1) along with the reduction of metal contents. All fishes in P1 cage died 100% on 3 days later after the experimental setting, while all fishes in the P6 died 100% on 9 days later. Overall, these results evidently provide a key methodology for pilot test using the disposal facility and also clarify the toxicity of AMD once again, so this approach used in the pilot facilities here may reduce the acidic and toxic effects in the abandoned mining drainage.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.162-162
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• 2000

• 대한임상검사과학회지
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• 제37권2호
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• pp.111-117
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• 2005

The purpose of this study is to provide the basic guidelines of spatial and physical environment for the planning and design of clinical laboratory by analysing the extent of satisfaction of clinical laboratory scientists. The data for this analysis was gathered from March to May 2005 by the questionnaires of 208 clinical laboratory scientists who work in the 13 hospitals. All the collected data was analyzed by the SPSSWIN program. In this study, the satisfaction measurement tool was composed with 8 items and 5 score scale. The mean score of satisfaction for spatial and physical environment was 2.89 out of 5.0, "noise" was the lowest 2.40, "temperature and moisture of the lab." was 2.72, "lab. area, service area and administration area" was 2.77, "passageway space" was 2.94, circulation of workers was 2.94, "color of finish" was 3.19, "lighting of lab." was the highest 3.39. In conclusion, various factors, noise, temperature and moisture, clinical lab area, were evaluated to moderate dissatisfaction. Noise was especially the first serious problem in clinical lab. Considering the high growth of the number of tests, the planning of the clinical laboratory size should be considered not only to provide the optimal size but how it will correspond to the growth of the number of tests. Therefore the arrangement of each section need to be flexible in arrangement which is inevitable in expansion and reconstruction in the future.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.836-839
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• 2005

A limit switch box is used for a indicator of a valve actuator. This device indicates an opening and closing of a valve or throttle in a valve actuator. In a ship, equipments are required safety and robustness because of a rough environment and a specific condition during a voyage. However, the limit switch box is used in an indoor environment generally. In order to evaluate the endurance of the limit switch box used in an indoor environment, the endurance tests against salt water have been conducted. Experiment results showed that the limit switch box was corroded severely. Thus, this study developed a new limit switch box which can be used at an outdoor environment. The housing of the developed limit switch box was made by an stainless steel to prevent corrosion.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권1호
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• pp.53-61
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• 2020

This study assessed the feasibility of coal mine drainage sludge (CMDS) as a stabilizing agent for mercury contaminated soil through pot experiments and batch tests. In the pot experiments with 43 days of lettuce growth, the bioavailability of mercury in the amended soil and mercury content of the lettuce were decreased by 46% and 50%, respectively. These results were similar to those of the soil amended with the sulfide compound (FeS) generally used for mercury stabilization. Thus, CMDS could be an attractive mercury stabilizer in terms of industrial by-product recycling. Batch tests were conducted to examine mercury fractionation including reactions between the soil and acetic acid. The result showed that some elemental fraction changed to strongly bounded fraction rather than residual (HgS) fraction. This made it possible to conclude that mercury adsorption on oxides in CMDS was the major mechanism of stabilization.

• The Plant Pathology Journal
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• 제20권4호
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• pp.283-288
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• 2004

Four Erwinia carotovora strains isolated from potatoes showing blackleg symptoms and rotted Chinese cabbage were analysed by biochemical tests and sequence analysis of 16S rDNA and 16S-23S rRNA intergenic spacer (IGS) regions, and the data were compared to related E. carotovora strains. Based on the results of the biochemical tests and sequence analysis, 2 of the 4 strains were identified as E. carotovora subsp. carotovora (Ecc), whereas the rest strains were distinct from Ecc. The last two strains, HCC3 and JEJU, were biochemically similar to E, carotovora subsp. atroseptica (Eca). However, the results of sequence analysis and Eca-specific PCR assays showed that the strains were distinct from Eca. On the basis of 16S rDNA sequence analysis, HCC3 and JEJU strains were placed in E. carotovora subsp. odorifera and E. carotovora subsp. wasabiae, respectively. The results of sequence analysis and specific PCR assay for Eca indicated that Asian Eca strains were distinct from European Eca strains, although they were phenotycally homogeneous.

• 항공우주기술
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• 제3권2호
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• pp.124-132
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• 2004

본 논문은 KSLV-I의 추력기 제어기로 사용되는 TCU(Thruster Control Unit)의 하우징과 PCB의 정적 및 진동해석에 관한 것이다. KSLV-I(Korea Space Launch Vehicle-I)에 장착되는 전자유닛들은 KSLV-I의 비행환경을 모사하는 환경시험을 통과하여야만 비행환경에서 기능 및 성능에 문제가 없다는 가정 하에 장착이 된다. 이 중 가장 문제가 되는 진동 및 충격시험에 대한 설계기준을 제시하였으며 설계된 하우징과 PCB가 이 설계 기준에 타당한지를 검토하였다. 설계기준을 만족하기 위해서 하우징을 재설계하였으며 검토결과 주어진 환경시험에 파손되지 않고 정상 작동할 것이라는 결론을 얻었다.

• KIEAE Journal
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• 제14권3호
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• pp.97-103
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• 2014

This study aimed at developing integrated logic for controlling heating device and openings of the double skin facade buildings. Two major logics were developed-rule-based control logic and artificial neural network based control logic. The rule based logic represented the widely applied conventional method while the artificial neural network based logic meant the optimal method. Applying the optimal method, the predictive and adaptive controls were feasible for supplying the advanced thermal indoor environment. Comparative performance tests were conducted using the numerical computer simulation tools such as MATLAB (Matrix Laboratory) and TRNSYS (Transient Systems Simulation). Analysis on the test results in the test module revealed that the artificial neural network-based control logics provided more comfortable and stable temperature conditions based on the optimal control of the heating device and opening conditions of the double skin facades. However, the amount of heat supply to the indoor space by the optimal method was increased for the better thermal conditioning. The number of on/off moments of the heating device, on the other hand, was significantly reduced. Therefore, the optimal logic is expected to beneficial to create more comfortable thermal environment and to potentially prevent system degradation.