• 정보처리학회논문지B
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• 제8B권6호
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• pp.705-717
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• 2001

이 논문에서는 카메라로 연속으로 촬영한 일련의 그레이레벨 영상으로부터 전방의 차량을 포착하기 위한 빠른 차선검출방법을 제안한다. 개별 영상에서 가려지지 않는 제한된 영역을 대상으로 차선의 위치를 검출하고, 에지 영상을 이용하여 차선의 기울기를 구한다. 이를 근거로 차량이 존재할 가능성이 있는 관심영역을 구하고 그 영역 내에서 에지 성분을 이용하여 구조적 방법으로 전방 차량의 위치를 포착한다. 제안된 방식의 효과를 검증하기 위해 노트북 PC와 PC용 CCD 카메라로 도로에서의 영상을 촬영하고 차선검출알고리즘을 적용한 처리 시간, 정확도, 차량검지 등의 결과를 보인다.

• 산업경영시스템학회지
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• 제21권45호
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• pp.101-112
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• 1998

Data mining, which is also referred to as knowledge discovery in database, means a process of nontrivial extraction of implicit, previously unknown and potentially useful information (such as knowledge rules, constraints, regularities) from data in databases. The discovered knowledge can be applied to information management, decision making, and many other applications. In this paper, a new data mining problem, discovering sequential patterns, is proposed which is to find all sequential patterns using sampling method. Recognizing that the quantity of database is growing exponentially and transaction database is frequently updated, sampling method is a fast algorithm reducing time and cost while extracting the trend of customer behavior. This method analyzes the fraction of database but can in general lead to results of a very high degree of accuracy. The relaxation factor, as well as the sample size, can be properly adjusted so as to improve the result accuracy while minimizing the corresponding execution time. The superiority of the proposed algorithm will be shown through analyzing accuracy and efficiency by comparing with Apriori All algorithm.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권2호
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• pp.15-22
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• 2018

Aqua regia extraction for the quantification of heavy metals and As in contaminated soils was investigated as one of preliminary steps for on-site monitoring using sensor technology. Soil samples were taken from closed railway depot, closed mines, and closed refinery and various extraction conditions including $30^{\circ}C/15min$, $30^{\circ}C/30min$, $30^{\circ}C/60min$, $30^{\circ}C/120min$, $80^{\circ}C/15min$, $80^{\circ}C/30min$, $80^{\circ}C/60min$, $80^{\circ}C/120min$ were tested. The optimal extraction condition was determined as $80^{\circ}C/60min$ because the extraction efficiencies of Zn were relatively low and did not reach the targeted level (80-100% of original concentrations) for $30^{\circ}C$ conditions. It was found that the fractionation of heavy metals and As using the sequential extraction method was useful to understand the degree of metal extraction. In order to enhance the extraction efficiency within short extraction time, ultrasound technology using a 20 kHz horn-type sonicator was additionally used for $30^{\circ}C/15min$. It was revealed that ultrasound could significantly enhance the extraction efficiency and pulsed irradiation showed higher efficiency than continuous irradiation due to the less formation of bubble clouds. However high temperature condition ($80^{\circ}C$) was required to achieve high extraction efficiency for Zn in spite of the use of ultrasound.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.46-51
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• 2000

Environmental quality regulations are used to establish the maximum permissible concentrations of heavy metals before a site can be deemed to be polluted or contaminated. This paper compares the results obtained by 0.IN HCl extraction and acid extraction method(HNO$_3$+HClO$_4$.HCl). The leaching efficiency of 0.1N HCl extraction is directly proportional to the final pH of leachate, due to the different solubilities of the heavy metals at different pH values, The severe differences between 0.1N HCl-extractable and total metal contents result mainly from the buffering effect of carbonates, present in sediment. samples. Application of sequential extraction experiments to some sediments collected from gully pot in Seoul illustrates a much stronger scavenging effect by Fe and Mn-hydroxides, carbonates and organic phases. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be: Mn>Zn>>Co>Cd>>Cu>Pb>Cr>Fe, in spite of large differences in heavy metal content and localization. Changes in the physicochemical environments (such as acidification) caused by a traffic accident may result in the severe environmental pollution of heavy metals of surrounding area( surface water and rivers).

• 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.

• Environmental Engineering Research
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• 제17권3호
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• pp.145-150
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• 2012

Pb-contaminated soil at a clay shooting range was analyzed by the sequential extraction method to identify metal binding properties in terms of detrital and non-detrital forms of the soil. Most of the metals in the soils existed as non-detrital forms, exchangeable and carbonate-bound forms, which could be easily released from the soil by a washing method. Therefore, the characteristics of Pb desorption for remediation of the Pb-contaminated soil were evaluated using hydrochloric acid (HCl) by a washing method. Batch experiments were performed to identify the factors influencing extraction efficiency. The effects of the solid to liquid (S/L) ratio (1:2, 1:3, and 1:4), soil particle size, and extraction time on the removal capacity of Pb by HCl were evaluated. Soil samples were collected from two different areas: a slope area (SA) and a land area (LA) at the field. As results, the optimal conditions at 2.8 to 0.075 mm of particle size were 1:3 of the S/L ratio and 10 min of extraction time for SA, and 1:4 of the S/L ratio and 5 min of extraction time for LA. The characteristics of Pb desorption were adequately described by two-reaction kinetic models.

• 정보관리학회지
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• 제21권3호
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• pp.289-303
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• 2004

이 연구에서는 이용자가 여러 곳에 분산되어 있는 문서들을 일일이 보지 않고 하나의 요약문에서 쉽게 질의에 맞는 답을 찾을 수 있는 가장 효율적인 방안을 제시하고자 하였다. 이를 위해, 클러스터링 기법, 단락확장 기법, 두 기법의 특성을 반영한 혼합 기법 등 세 가지 복수문서 요약 기법의 성능을 평가하는 실험을 수행하였다. 요약기법 평가 기준으로는 요약 정확률과 요약문내 정보 중복도를 적용하였다. 실험결과 이용자 질의에 따라 여러 문서를 요약하는 최적 기법으로 문장검색을 기반으로 한 순차적 단락확장 기법을 제안하였다. 순차적 단락확장은 특히, 용약의 대상이 되는 문서가 대용량인 환경에서 정확한 정보를 찾아 요약문을 생성하는 성능이 가장 우수한 것으로 나타났다.

• 한국식품과학회지
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• 제18권5호
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• pp.335-338
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• 1986

토마토의 색도를 측정하기 위해 색소의 sequential extraction을 이용한 spectrophotometric technique을 시도하였다. 파장 480nm 와 660nm에서 각기 80% acetone과 chloroform으로 추출된 용액의 흡광도를 합한 다음 두 파장에서의 총 흡광도 차이를 구한 결과 토마토의 숙성(ripening) 정도가 잘 반영되었다. 이러한 측정방법은 토마토 색소의 객관적 측정을 위한 간단하고 신뢰성 있는 방법으로 간주된다.

• 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.

• 한국환경과학회지
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• 제1권1호
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• pp.89-96
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• 1992

In this study , we have investigated leaching characteristics of heavy metals and alkalinity centering around steel mill slags by several extraction methods, for the purpose of risk assessment that exert influence on environment and offer of the foundation data of reuse by slags. Korean standard method, U.S.EPA Extraction Procedure, alkalinity extraction test and 9 step sequential fractionation experiment by Miller et al. were carried out for investigating teachability of steel mill slags. As a result of this experiment, heavy metals were little detected and it was considered that alkalinity does not exert a bad effect around environment in slabs with large particle size. By the result of 9 step fractionation experiment, heavy metal contents in slags were not plentiful, in addition, even comparatively plentiful contended heavy metals, for the most part, were likely to detained or bonded in silica matrix. Therefore, in case of slags with large particle size, it seems that teachability of heavy metals were next to impossible that is existed as a safety condition.