• Analytical Science and Technology
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• v.16 no.3
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• pp.232-239
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• 2003

The river sediments were collected from 4 points of Seoknam river, one point of Miho river and one point of the joining area of two rivers. For preparation of sample, three sediment samples were collected for the surface, middle and lower part of the sediment at each sampling point. The elemental concentrations were analyzed by neutron activation analysis using HANARO research reactor at Korea Atomic Energy Research Institute, and the concentrations of 30 elements were determined by the relative method using standard reference material of NIST. As a result of analysis, it was found that when the examination and prediction of contamination distribution about the site where the contamination site of river is connected to the lower river is done, the specific gravity of elements which is contained in the sediment and the speed of a current of river should be considered and also found that when the samples for concentration analysis in the river sediments are collected, for the establishment of regional representatives in samples, the range of sampling depth should be determined considering the specific gravity of elements and the speed of a current.

• Journal of Food Hygiene and Safety
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• v.3 no.3
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• pp.131-137
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• 1988

A pesticide monitoring survey was undertaken for the both 30 samples of pears and sweet persimmons from chief producing districts in1985 to evaluate pesticide residues in these agrcultural products and also to give basic informations in establishing maximum residue limits. Pesticide residues in pears were detected with fairly low in 7-60% of total samples. Even the maximum residue levels were only in the amount of 1/53-2/3 compared with maximum residue limits established in fruits in Environment Administration, Korea. Most of the residues (71-82%) was remained in peels of pears. Incase of sweet persimmons, captan, captafol, EPN, parathion, and phenthoate residues were also detected with fairly low in 3-20% of total samples. Presently, it is considered that pesticide residues in pears and sweet persimmons may be no harmful levels for food commodities.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.155-164
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• 2010

Emission from biomass combustion such as meat charbroiling is an important source of organic aerosol. Since source profiles are necessary input profiles for source apportionment of aerosol by a chemical mass balance model, meat cooking organic source profiles are developed by measuring organic marker compounds, including palmitic acid, stearic acid, oleic acid and cholesterol as well as PAH compounds. Emissions from meat and pork charbroiling are collected on quartz filters with a PM10-high volume sampler, extracted with organic solvents, derivatized with diazomethane/TMS and analyzed by GC/MS isotope dilution method. Organic and elemental carbon are also analyzed by an OCEC analyzer. Wt.% of cholesterol to the organic carbon(OC) content from beef and pork charbroiling is only 0.056 and 0.062, but wt. % of all saturated fatty acids to the OC content from beef and pork charbroiling is 2.727 and 2.022, and the wt% of all unsaturated fatty acids to the OC content is 0.278 and 0.438, respectively. Content of total PAH compounds to the OC content from beef charbroiling is higher than that from pork charbroiling, and those are 0.116 wt% and 0.044 wt%. Among PAH compounds benzo(a)pyrene as a single compound is account for 0.0071 wt% and 0.0023 wt% of OC content from beef and pork charbroiling. Ratios of marker compound to cholesterol are calculated, and those values are in good agreement with the values already reported at the food cooking emission, indicating that they can be used as organic source profiles for the apportionment of organic aerosol.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.685-685
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• 2012

농업용수 및 친수공간 확보, 경관 향상 등의 다양한 목적을 위한 보의 건설은 하천의 흐름을 차단하여 보를 기준으로 상 하류의 흐름특성을 변하게 하고 토사퇴적에 많은 영향을 미치게 된다. 토사의 퇴적으로 인해 하상이 상승되면 홍수시 홍수위 상승에 의한 치수적인 문제점이 발생하고 토사의 침식이나 공급차단으로 인해 하상이 저하되면 하상세굴로 인해 교각이나 수위관측소와 같은 하천시설물의 기능이 저하되며 하천부지의 변화 등 하천유역 관리에 많은 영향을 준다. 따라서 보 상 하류의 하상변동을 예측하고 분석하는 것은 하천 관리에 매우 중요하다. 본 연구에서는 공주보 건설 기간 중 공주보를 기준으로 상 하류의 하상변동 및 퇴적 토사의 입도 변화양상을 조사하기 위해 모니터링 지점을 선정하였고, 하상단면 수심측정기를 이용하여 하상의 형상 모니터링을 통해 하상변동 양상을 분석하였으며 토사시료를 채취하여 하상재료 입도분포를 분석하였다. 그 결과 공주보 상류 모니터링 지점의 하상 평균높이가 0.52m 낮아진 것으로 측정되었고, 하류 모니터링 지점 역시 하상고의 평균 높이가 0.36m 저하된 것으로 측정되었으며, 하상형상의 모습은 큰 차이를 보이지 않았다. 보의 건설로 상류측의 토사퇴적이 예상 되었으나 모니터링 시에는 수문이 개방되어 하천의 흐름이 비교적 원활하여 보 상류측에 토사의 퇴적현상이 발생하지 않은 것으로 판단된다. 또한, 하상재료를 채취하여 균등계수 및 곡률계수를 통해 입도분포를 분석한 결과 체가름시험 규정에 의해 '나쁜입도'로 분류되었다.

• Journal of the Korean GEO-environmental Society
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• v.8 no.6
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• pp.53-60
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• 2007

L/EPS, manufactured in the shape of block and used for civil engineering, is a lightweight material with an excellent resistance to compression, and provides a superb self-sufficient stability. EPS is a suitable material capable of resolving the problem of settlement and lateral flow if it is applied as the soil on soft ground. The Korean Standards (KS) has not yet proposed any testing method for use of EPS as an engineering banking material. Only its testing and quality ordinance as a heat insulation material has been standardized. The design criteria for EPS has been established and applied through the trial construction of KHC (Korea Highway Corporation) and quality test of manufacturer, but most studies on them have been confined to factory products. This study is focused on comparing and analyzing long-term durability by conducting cyclic load test, freezing and thawing test, absorption rate test and others. EPS used in the test was chosen from construction sites and factory products, focusing on the long-term durability of EPS depending on the passage of time. Unconfined compression test results indicated that the strength of collected samples was lower than factory products. While the triaxial compression test results indicated that the shear strength increased in proportion to the increase of confining pressure, and factory products had declining shear strength as the confining pressure rose.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.81-82
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• 2000

미국 EPA에서 $PM_{2.5}$를 새로운 대기환경기준으로 설정함에 따라 $PM_{2.5}$를 측정하기 위한 새로운 Reference method가 설정되었다. 새로운 $PM_{2.5}$측정방법(Reference method)은 2.5$\mu\textrm{m}$ cut-diameter를 가진 cyclone을 통하여 16.7 L/min 유량으로 24시간동안 테프론 필터에 시료를 채집하는 것으로 규정하고 있다. 최근에 국내외에서 $PM_{2.5}$에 대한 활발한 연구가 수행되고 있으며 이들 연구의 대부분이 현재 미국 EPA의 $PM_{10}$ Reference method인 Dichotomous 샘플러를 이용하여 테프론 필터에 시료를 채취하고 있다 (중략)

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.364-366
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• 2021

본 논문은 비전 기술을 기반으로 RHS 칼라차트를 이용하여 작물의 색채를 측정하는 특성조사기준에 관한 연구를 수행하였다. 다양한 색상을 가진 작물의 색채를 측정하기 위해 시료 채취 후 표준광원 촬영장치 광원 6500K 환경하에 촬영한 영상을 기반으로 분석 위치를 관심영역 선정 후, k-mean clustering을 활용한 세그먼테이션 방법을 통해 대표 RGB 색상을 획득한다. 획득한 RGB 색상과 RHS 칼라차트의 RGB 색상을 유클리디언 거리를 이용하여 최소화하는 RHS 칼라차트 정보를 추정하였다. 7가지 작물 시료에 대해 작물 형질 분석 전문가들이 측정한 결과와 비교 시 전체 평균 △E 5.013의 오차를 결과로 도출하였다.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.45-53
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• 1999

The soil samples were measured at 90 sites of Soil's Network In 1997~1998 which was established for the investigation of soil contamination in Seoul. This study was more focused to measure and analyze for BTEX(Benzene, Toluene, Ethylbenzene and Xylene) concentration in the Soil Network. Also, the samples were analyzed by Purge & Trap method. As a result, the BTEX were detected at all sampling sites in Seoul. The Min. Max and Mean BTEX concentration were respectively 0.047mg/kg, 2.618mg/kg and 0.437mg/kg in 1998. The concentration of the BTEX detected at all sampling sites was lower than that of the intervention standards(at industrial areas) of Soil Preservation Act.

• Journal of Radiation Protection and Research
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• v.37 no.4
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• pp.226-230
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• 2012

The gross alpha analysis of nasal smear samples for the radiation emergency and the additional follow-up steps were established. Cotton swab sticks using in local hospitals for nasal smear in Korea were used for the verification. The measurement results of standard samples spiked with certified reference source were well agreed within ${\pm}20%$ compared with reference values. The clearance ratio of smear samples conducted with wet smear condition showed higher value. To eliminate the quenching effect of liquid scintillation samples, dry of smear samples should be followed up before counting samples. Based on the measurement results, medical decision levels and internal dose assessment were established for the victims in the beginning of radiation emergency.

• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.27-35
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• 2004

There are two methods in estimating the remaining life of in-service airfield concrete pavement. They are a method simply using the past accumulated traffic and a method using the theoretical mechanistic analysis. Since the former method is somewhat far from the actual condition, the latter method is widely used by most engineers and researchers. The most essential component of the latter method is the fatigue model of the concrete slab. A fatigue model for airfield concrete pavement is developed in this study by a series of fatigue tests using 30 concrete cylinder specimens obtained from a 10 year old in-service airfield concrete slab. Strengths for the stress ratio calculation were obtained from the split tensile test of the cores sliced. Fatigue test mode was repeated split tensile test. The R2 of developed fatigue model was 0.5. Specimens taken from another airport had been tested for validation of the model. The results showed a good fit to the model. It was also found that the fatigue life predicted from the model was a tittle greater when the stress ratio is greater than 80 percent than other fatigue models developed earlier in America.