• 한국광물학회지
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• 제23권1호
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• pp.85-91
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• 2010

NIST 표준시료인 SRM 2710(Montana Soil)을 대상으로, 중금속의 지화학적 존재형태 연구에 일반적으로 적용되는 Tessier 연속추출법과 최근 소개된 초음파연속추출법을 적용 및 비교하여 오염 토양 내 중금속의 효율적 분석방법을 제시하고자 하였다. As, Cd, Cu, Pb, Zn의 총함량을 USEPA Method 3050B, KBSI Method, 초음파 추출법을 적용하여 분석한 결과, 모두 공인 분석값에 가까운 값으로 측정되었다. Tessier 연속추출법과 초음파 연속추출법의 비교 결과, 원소별 및 단계별 추출 양상과 추출효율이 두 방법 모두 거의 동일한 것으로 나타났다. 초음파 연속추출에는 총 3시간 정도 소요되었으며, 기존의 Tessier 연속추출법의 12시간 정도와 비교할 때 크게 단축되었다. 유기오염 시료의 전처리법으로 흔히 사용되는 초음파 추출법은 비교적 짧은 시간 내 추출이 이루어지고, 고온의 가열이 필요치 않으며, 시료에 직접 강한 파장을 주어 추출하기 때문에 비교적 높은 추출효율을 보이는 효과적인 방법이라 할 수 있다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.95-105
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• 2011

Total extraction method and environmental standards for heavy metals in soils were revised in regulation recently. In case of Area 3, as the law amended, the soil pollution level has gone up to 4 to 13 times higher depending on the type of heavy metal. In this study, it compares the properties of heavy metals of soil by sequential extraction and total extraction methods depending on the analysis method, using the soil around mine. In case of arsenic, the soil pollution level has gone up to 4 times higher, but 6 to 10 times in the sample soil. Also, according to the results of portability evaluation depending on the type of existence form of heavy metal it exists as residual form in mine waste rock, which is less likely to move, while it exists as migrated form in tailing. Therefore, it should be considered to evaluate the soil pollution and decide the contaminated bounds depending on the existence form of heavy metals on soil to restore the polluted soil.

• 한국환경과학회지
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• 제8권2호
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• pp.197-204
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• 1999

The extent of heavy metal pollution in agricultural in soils near the abandoned mine land site was investigated using their concentrations from the 47 sampling sites in B mine. Samples were prepared using 0.1N HCI - Korean Standard Methods - and then analysed for Cd, Cu, Pb, As and Cr by Inductively Coupled Plasma Spectrometer. In addition, soil and mine tailing samples were sequentially extracted to investigate the chemical speciation of heavy metals in them. The soils in the vicinity of mining area are highly contaminated by heavy metals ranging up to 5.96mg Cd/kg, 253.3mg Cu/kg, 76.7mg Pb/kg, and 15.45 mg As/kg, according to the analysis of Korean Standard Methods. The heavy metal levels by the sequential extraction are much higher than its level by Korean Standard Methods, and little correlated with each other. Based on the results, it is suggested that the As pollution in agricultural soils near the AMLS should be dealt as of prior significance in establishing reclamation strategies for the area.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권1호
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• pp.42-50
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• 2011

Potential risk of heavy metals to various receptors including humans depends on the bioavailability of the heavy metals in soil. In this study, the heavy metal extraction methods using 0.1N HCl and aqua regia were compared with the Tessier's sequential extraction method to assess whether these two methods can be used to determine the plant-available heavy metal concentrations. The contamination characteristics of copper (Cu), cadmium (Cd), lead (Pb), and arsenic (As) found in soils collected from 75 sites around the closed Janghang smelter were analyzed by extracting heavy metals using 0.1 N HCl, aqua regia, and the Tessier's sequential extraction method. The portion of metals bioavailable to plants is considered as the sum of the fraction 1 (exchangeable) and the fraction 2 (carbonates binding) of the Tessier's 5-step sequential extraction method, which were determined to be 3.1 ${\pm}$ 3.82, 0.6 ${\pm}$ 0.15, 20.6 ${\pm}$ 18.78, and 7.0 ${\pm}$ 6.48 mg/kg for Cu, Cd, Pb, and As, respectively, in this study. When the extraction using aqua regia and the Tessier's extraction method were compared, the extracted Cu and Pb concentrations did not show significant differences, whereas the extracted Cd and As concentrations showed significant differences. These results indicate that the portion of Cd and As in the fraction 5 of the Tessier's sequential extraction can not be extracted using aqua regia. Using aqua regia, which is the official test method, higher concentrations of Cu, Cd, Pb and As were extracted than the sum of the fraction 1 and 2. The results show that only 9, 40, 39 and 10% of Cu, Cd, Pb and As using aqua regia can be uptaken by plants (i.e., plant-available). Using 0.1N HCl, the portion of Cd equivalent to about 66% the fraction 1 could be extracted, while, with Pb, the portion of the fraction 1 and about 90% of the fraction 2 could be extracted. With As, the portion equivalent to the fraction 1, 2 and 79% of the fraction 3 was extracted, while with Cu, the portion equivalent to the fraction 1, 2, 3 and 20% of the fraction 4 was extracted using 0.1N HCl.

• 펄프종이기술
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• 제45권5호
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• pp.30-36
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• 2013

Hydrophobic property of Kapok fiber was investigated by sequential removal of its components by different extraction methods. Acetone extraction for the removal of the hydrophobic extractives, holo-cel-lulose preparation after the removal of lignin and xylan extraction by potassium hydroxide was applied. The degree of hydrophobicity of each samples were measured by the water sorption ability. The water sorption ability of Kapok fiber was increased by the sequential treatment of acetone extraction, holocellulose preparation and xylan removal. Based on holocellulose compositional analysis by $^1H$-NMR spectroscopic method, the unusual high amount of the acetyl groups in the holocellulose of Kapok partially contributed to the hydrophobicity of Kapok holocellulose fiber.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.40-43
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• 2002

Electrokinetic remediation was studied for the removal of toxic heavy metals from tailing soils. This study emphasized the dependency of removal efficiency upon heavy metal speciation, as demonstrated by different extraction methods (sequential extraction, total digestion, and 0.1 N HC1 extraction). The tailing soils examined showed different physicochemical characteristics, in view of initial pH, particle size distribution, and major mineral constituents, and contained high concentrations of target metal contaminants in various forms. The electrokinetic removal efficiency of heavy metals was significantly influenced by their partitioning prior to treatment, and by the pHs of the tailing soils. The mobile and weakly bound fractions of heavy metals, such as exchangeable fraction, were easily removed by electrokinetic treatment (more than 90% in removal efficiency), whereas immobile and strongly bound fractions, such as organically bound and residual fractions, were not effectively removed (less than 20% in removal efficiency).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.1263-1266
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• 1998

In this paper, we propose an optimal feature extraction method for normally distributed multiclass data. We search the whole feature space to find a set of features that give the smallest classification error for the Gaussian ML classifier. Initially, we start with an arbitrary feature vector. Assuming that the feature vector is used for classification, we compute the classification error. Then we move the feature vector slightly and compute the classification error with this vector. Finally we update the feature vector such that the classification error decreases most rapidly. This procedure is done by taking gradient. Alternatively, the initial vector can be those found by conventional feature extraction algorithms. We propose two search methods, sequential search and global search. Experiment results show that the proposed method compares favorably with the conventional feature extraction methods.

• 한국멀티미디어학회논문지
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• 제20권5호
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• pp.740-747
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• 2017

A fast cell contour extraction method using CUDA parallel processing technique is presented. The cell contour extraction is one of important processes to analyze cell information in pathology. However, conventional sequential contour extraction methods are slow for a huge high-resolution medical image, so they are not adequate to use in the field. We developed a parallel morphology operation algorithm to extract cell contour more quickly. The algorithm can create an inner contour and fail to extract the contour from the concave part of the cell. We solved these problems by subdividing the contour extraction process into four steps: morphology operation, labeling, positioning and contour extraction. Experimental results show that the proposed method is four times faster than the conventional one.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1647-1654
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• 2008

The characteristics of arsenic(As) contamination were investigated on soils of 3 abandoned metal mine sites in Gangwon-do, Korea. Total forty nine soils were sampled to conduct standard methods(extraction by 1HCl), sequential extraction and column leaching test. Concentration of As extracted by 1N HCl was ordered as follows: A mine > B mine > C mine, and the concentration of arsenic in the soils of A mine was significantly greater than that at any other cases and all samples of A mine were exceeded the national regulation of $6mg \;kg^{-1}$. In the results of sequential extraction, the potential contamination risk for groundwater and plants was ordered as follows: C mine > B mine > A mine because the C mine showed the relatively greater mobility and bioavailability of fraction than any other mines. And, in colume test, concentration of As was ordered as follows: C mine > B mine > A mine, and it was expected that these results were connected with fraction characteristics of the mine sites. Therefore adequate leaching investigations should be used to simulate the effect of natural leaching conditions, and to predict both the potential mobility of metals to groundwater and their bioavailability to plants under natural conditions.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권1호
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• pp.69-78
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• 1998

Contents of heavy metals (Cr, Cu, Zn, Cd, and Pb) in the sediments of Ulsan Bay were investigated by the sequential extraction methods that classifies heavy metals into five types of chemical forms: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. The analytes were determined by using an ICP-MS. Total Cr concentrations in the sediments were in the range of 41.6-96.4, Cu 60.7-680, Zn 189-1954, Cd 33.1-83.4, and Pb 138-567 mg/kg. Results of sequential fractionation indicates that relatively high proportion $(\~44\%)$ of Cu is associated with organic matter A large proportion of Pb is associated with three types of chemical forms: Fe-Mn oxides, organic matter, and residual. There were significant correlation in concentrations between the exchangeable components and total organic carbons. The heavy metals in the residual phase cannot be easily released to the environment since these are bound to the crystal lattice. But, reducible and organic Phases cfn a significant amount of most heavy metals. Therefore. there is potential danger of a substantial amount of metals becoming chemically mobile with environmental changes.