• 한국방사선학회논문지
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• 제5권6호
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• pp.335-341
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• 2011

본 연구는 미나리와 울금의 방사선 피폭이 어떠한 영향이 미치는지 알아 보고자 하였다. 실험동물은 ICR계 5주령 25~30g 수컷 50 마리를 마우스를 사용하여, 5 마리를 하나의 군으로 3 Gy 대조군(A), 5 Gy대조군(B), 3 Gy 미나리 전처치(C), 5 Gy 미나리 전처치(D), 3 Gy 미나리 후처치(E), 5 Gy 미나리 후처치(F), 3 Gy 울금 전처치(G), 5 Gy 울금 전처치(H), 3 Gy 울금 후처치(I), 5 Gy 울금 후처치(J)으로 설정하였고, 대조군(A, B)은 방사선 조사 후 7 일 동안 생리식염수 500mg/kg/day)를 마우스에 경구투여 하였고, 후처치 대조군(E, F, I, J)도 방사선조사 후 7일 동안 미나리(500mg/kg/day)와 울금(500mg/kg/day)을 각각 마우스에 경구투여 하였다. 또 이와 같은 방법으로 전처치 대조군(C, D, G, H)은 미나리(500mg/kg/day)와 울금 (500mg/kg/day)을 각각 마우스에 7 일 동안 경구투여 후 방사선 조사를 하였다. 그 결과 3 Gy 대조군에서 백혈구 평균수치(마우스 5 마리)는 평균 200K/${\mu}L$, 3 Gy 미나리 전처치군에서는 평균 6,46K/${\mu}L$로 정상수치(1.8-10.7 K/${\mu}L$)로 되었다. 3 Gy 울금 전처치의 백혈구 평균수치는 23.33K/${\mu}L$로 정상수치는 아니지만, 200K/${\mu}L$에 비하여 정상수치에 가까워졌음을 알 수가 있다. 3 Gy 대조군에서 림프구의 평균 수치는 118.87K/${\mu}L$로, 3 Gy 울금 전처치군은 1.51 K/${\mu}L$로 림프구 정상수치(0.9-9.3K/${\mu}L$)로 나타내었다. 혈소판에서는 3 Gy 대조군의 평균 수치는 4000K/${\mu}L$, 3 Gy 미나리전처치군은 1107 K/${\mu}L$, 3 Gy 울금 전처치군은 2759.6 K/${\mu}L$로 혈소판정상수치(592-2972 K/${\mu}L$)로 나타내었다. 위의 결과로 미나리와 울금이 방사선 피폭에 대한 예방적 차원에서 방어효과가 있는 것으로 사료되었고, 동물실험에서는 혈구수치가 정상수치로 돌아오는 것을 알 수가 있었다. 이 실험을 바탕으로 향 후 다양한 연구가 선행되어야 할 것으로 사료되는 바이다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.584-587
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• 2008

최근 새로운 천연가스 수송/저장 방법으로 가스 하이드레이트 형성법이 주목받고 있다. 본 연구에서는 천연가스의 저장 매체로 다공성 실리카 젤을 사용하였다. 다공성 매질을 사용할 경우 물이 기체와 접촉하는 면적이 극대화되어 하이드레이트로의 전환율이 높아진다. 기공의 직경이 각각 6.0, 15.0, 30.0 nm의 실리카 젤을 사용하여 270 - 285 K의 온도 범위와 0.5 - 3.0 MPa의 압력 범위에서 기공 크기의 분포를 고려하여 에탄 하이드레이트의 3상 평형점 (하이드레이트 (H) - 물 (LW) - 기상 (V))을 측정하였다. 기공의 크기가 작아질수록 벌크 상태의 에탄 하이드레이트에 비해 하이드레이트 평형 조건이 온도는 낮아지고 압력이 높아지는 저해효과가 커짐을 알 수 있었다. 천연가스 수송/저장으로의 응용을 고려할 경우 저해효과가 적은 30.0 nm 이상의 실리카 젤을 사용하는 것이 유용할 것으로 사료된다. 본 연구의 결과는 심해저 천연가스 개발, 이산화탄소 심해저장 등의 가스 하이드레이트 응용 연구에도 유용한 기초자료가 될 것이다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.217-220
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• 2005

Zero tail type mini excavator is small in size and capacity compared with medium or large excavator. Therefore noise and heat problems are major issues in design due to layout of each components such as engine and hydraulic module. It is necessary to assure reduction of noise and vibration in construction machine, due to be enforced regulation for high noise construction machinery at home and abroad. The objective of this study is to provide basic data which is apply to predict noise effect in detail design stage by estimating noise of cabin for zero tail type mini excavator.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.156-161
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• 1998

As grouting materials for ground improvement, silicate materials such as water glass, silica-sol and so forth are used worldwide. However, they may pollute underground water. In this study, fish poison test(Korean standard industrial code KS M 0111) which estimates toxicity for fish is applied to evaluate the toxic effect by grouting materials. From the test result of the sample made of LW, LC50(Median Lethal Concentration) reaches within 24 hours. In case of the silica-sol, it does not even in 96 hours. Therefore, we can conclude that the sililca-sol grouting method is more free from the danger of underground water pollution. From the result that the mortality of fish under the condition of pH 8.6 is 0% within 96 hours, the groundwater can be saved by controlling pH below 8.6 for the grouting in the field.

• 한국환경과학회지
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• 제14권10호
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• pp.911-917
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• 2005

A comparison between the estimated chlorophyll a from OSMI, the SeaWiFS and the chlorophyll a measured from the research cruises of National Fisheries Research and Development Institute was made. The updated empirical algorithm for calibrating and validating of the estimated chlorophyll a in the East China Sea was formulated by relationship between the estimated chlorophyll a and the field one. The relationship between the chlorophyll a and the band ratio(nLw490/555) was still highest in the OSMI data after launching of KOMPSAT satellite. The distributions of OSMI chlorophyll a were compared with those of sea surface temperature, zooplankton biomass, and catch amounts of the Pacific mackerel in the East China Sea. In case of the relationships in specially winter seasons of 2002 and 2004, the zooplankton and the fish were totally depended on the distributions of SST than those of chlorophyll a.

• 한국안전학회지
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• 제15권2호
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• pp.118-125
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• 2000

Construction industry has one of the worst occupational health and safety records amongst all other industries. In this study, we developed a method to compute the severity rate (SR) and measured SR values of apartment construction incidents. The two-year records (1996-1997) from database by the Korea Industrial Safety Corporation (KISCO) were used in the current study. To determine the severity rate (SR), the lost workdays (LW) and the number of injured workers and fatalities (NIW) as well as the number of accidents (NA) were considered. These results appear to indicate that the SR measurement we developed in this study is adequate to estimate the safety of apartment construction environment.

• 한국안전학회지
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• 제9권2호
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• pp.3-11
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• 1994

This study discribes result of comparision of two other numerical method, method of characteristics (MOC) and Lax-Wendroff method(LWM) applied at wave action analysis of Intake and exhaust pipe. Partiality FCT(Flux Correct Transport) scheme is appeneded to LWM to protest unacceptable overshoots, occuring near discontinuity. The final conclusion of this study is that MOC should be replaced by a second order finite difference approach(such as the LW method). Clear benefits we can get by change are faster calculation, higher accuracy, conservation of mass and consistent calculation method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.292-295
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• 2006

Dimension and capacity of the zero tail type mini excavator are small as compared with medium or large excavators. Therefore, problems of the noise and the heat are major issues in design due to layout of each component such as the engine and the hydraulic module. It is necessary to reduce the noise and the vibration of construction machine, due to be enforced regulation for high noise construction machinery in the world. The objective of this study is to provide basic data which is apply to predict noise effect in detail design stage by estimating noise of cabin for zero tail type mini excavator.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.710-715
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• 1994

The program name TOLAPS is an acronym for Take-Off LAnding Profile Simulation. Some of the interesting features of this program is the ability to detect flight performance effects of airport altitude, ambient temperature, air pressure and wind. TOLAPS can also handle effects of TOW and LW. The program user can also calculate profiles by user difined flaps and thrust settings deviating from recommended standard settings for each aircraft. Wind effects on straight out flying as well as turns can also be demonstrated. Output form TOLAPS are either screen graphics of profiles (altitude, speed or thrust versus flight distance) or flight track. Profiles can also be made in a tabular form, ready for use in most airport noise calculation programs. In this way, TOLAPS is a valuable tool to evaluate effects of noise abatement procedures.

• 한국환경복원기술학회지
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• 제17권4호
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• pp.57-67
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• 2014

The vigor condition of trees is an important indicator for the management of urban forested area. But difficulties in how to assess the tree vigor condition still remain. Previous efforts were limited in the 1) measurement of single indicator rather than using multiple indices, 2) purpose-oriented measurement such as for air-pollution effect or specific pathological symptom, and 3) ordinal-scale evaluations by field crews 4) despite human errors based on his/her experiences or prior knowledge. Therefore, this study attempted to develop a quantitative and objective methodology for assessing tree vigor condition, by measuring multiple modules and building the profile inventory. Furthermore, the possibility and limitations were discussed in terms of schematic frames describing tree vigor condition. The vigor condition of 56 flowering cherry plants in urban park were assessed by in-situ measurements of following eight items; growth of crown(Gc), growth of shoots, individual tree volume(Vol), plant area index, woody area index, leaf area index, leaf chlorophyll content(Lc) and leaf water content(Lw). For validation, these measurements were compared with the ranks of holistic tree vigor condition, which were visually assessed using a 4-point grading scale based on the expert's knowledge. As a result, the measures of each evaluation item successfully highlighted a variety of aspects in tree vigor condition, including the states of both photosynthetic and non-photosynthetic parts. The variation in the results depending on evaluated parts was shown within an individual tree, even though the broad agreement among the results was found. The result of correlation analysis between the tested measurements and 4-point visual assessment, demonstrated that the state of water-stressed foliage of the season (Lw) or the development of plant materials since sapling phase (Vol) could be better viewed from the outer appearance of trees than other symptoms. But only based on the visual assessment, it may be difficult to detect the quality of photosynthesis (Lc) or the recent trend in growth of trees (Gc). To make this methodology simplified for the broad-scale application, the tested eight measurements could be integrated into two components by principal component analysis, which was labelled with 'the amount of plant materials' and 'vigor trend', respectively. In addition, the use of these quantitative and multi-scale indicators underlies the importance of assessing various aspects of tree vigor condition, taking into account the response(s) on different time and spatial scale of pressure(s) shown in each evaluated module. Future study should be advanced for various species at diverse developing stages and environment, and the application to wide areas at a periodic manner.