• Journal of the Korean GEO-environmental Society
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• v.4 no.3
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• pp.79-88
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• 2003

This paper presents a numerical study of the spatial behavior of a linear absorbing solute in a heterogeneous porous medium. The spatially correlated log-normal hydraulic conductivity field is generated in a given two-dimensional domain by using the geostatistical method (Turning Bands algorithm). The velocity vector field is calculated by applying the two-dimensional saturated groundwater flow equation to the Galerkin finite element method. The simulation of solute transport is carried out by using the random walk particle tracking model with CD(constant displacement) scheme in which the time interval is automatically adjusted. In this study, the spatial behavior of a solute is analyzed by the longitudinal center-of-mass displacement, longitudinal spatial spread moment and longitudinal plume skewness.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.47-52
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• 2010

Physical, chemical and biological properties of soils and cadmium(Cd) content of Artemisia princeps var. orientalis collected from 10 metalliferous mines were analysed. Cd contents of unplanted soils and rhizosphere soils were not significantly different(p < 0.05), and mean values were 5.92 and 5.91 mg/kg, respectively. In addition, Cd content of rhizosphere soils were correlated with Cd content of Artemisia princeps (p < 0.05, ${R^2}_{shoot}$ = 0.3120, ${R^2}_{root}$ = 0.4177). Minimum data set(MDS) of soil quality parameters for statistical assessment of Cd uptake was established by principal component analysis, and it was identified as organic matter(OM), dehydrogenase activity(DHA), pH, exchangeable Mg. According to multiple regression analysis using the MDS, coefficients of determination ($R^2$) for Cd uptake of shoot and root of Artemisia princeps were found to be 0.3418 and 0.5121, respectively. This suggests that statistical soil quality assessment using the MDS seems a useful tool to interpret heavy metal uptake of plant.

• Polymer Science and Technology
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• v.6 no.1
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• pp.22-27
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• 1995

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2072-2078
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• 2011

In photovoltaic(PV) system, for obtaining maximum efficiency of solar power systems, the solar tracking system must be controlled to match position of the sun. In this paper, we design the solar tracking system to track movement of the sun using CdS sensor modules and to determine direction of the sun under shadow of directions. In addition, for an intelligent computation in tracking of the sun, a fuzzy controller is allocated to space avaliable for splitting area of fuzzy part for the fuzzy input space(grid-type fuzzy partition) in which a fuzzy grid partition divides fuzzy rules bases. As well, a simple model of solar tracking system is designed by two-axis motor control systems and the 8-direction sensor module that can measure shadow from CdS sensor modules by matching of axis of CdS modules and PV panels. We demonstrate this systems is effective for fixed location and moving vessels and our fuzzy controller can track the satisfactorily.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.36-36
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• 2003

목적： 고형성 종양에 특이적으로 발현하는 MR 분자영상용 조영제의 후보물질을 분자생물학적 방법 및 in vitro 분자영상기법을 이용하여 탐색하고자 하였다. 대상 및 방법： 암이 진행됨에 따라 유전자가 과발현되는 세포표면 단백질인 CD44 와 세포막에 존재하는 단백질분해효소의 일종인 MTI-MMP를 일차 선정하여 유전자 수준 및 단백질 수준에서 분자생물학적 방법으로 종양특이성에 대해 검증하였고, 특히 각종 암세포에서 발현양이 증가하는 CD44의 변형인 CD44v6 항체를 이용하여 생세포에서의 표적화에 대한 광학적 검증을 위해 초상자성 나노입자 대신 형광입자(FITC)를 결합하여 confocal microscopy로 실시간 표적화에 대한 분자영상을 획득하였다.

• Annual Conference of KIPS
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• 2007.05a
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• pp.653-656
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• 2007

과거의 기능 중심의 소프트웨어 개발방법론에서 벗어나 최근에는 서비스 중심의 컴포넌트 기반 소프트웨어 개발 (CBD: Component Based Development) 방법론이 새로운 개발 패러다임으로 각광을 받고 있다. 본 논문은 CBD 방법론 중 마이크로 소프트사의 MSF/CD 방법론을 기반으로 한 물리적인 설계를 할 때 기존의 CID (Component Interaction Diagram)에 Dispatch Agent 를 제안하였다. 실험 결과를 통해 제안된 기법이 component 서비스 속도를 향상시키고 보다 신속한 트랜잭션 처리를 제공함을 확인하였다.

• Journal of Soil and Groundwater Environment
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• v.16 no.4
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• pp.23-30
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• 2011

Risk based pollution level of Pb and Cd in metal contaminated soils depending on physicochemical properties of soil in a target site was assessed using biotic ligand model. Heavy metal activity in soil solution defined as exposure activity (EA) was assumed to be toxic to Vibrio fischeri and soil organisms. Predicted effective activity (PEA) determined by biotic ligand model was compared to EA value to calculate risk quotient. Field contaminated soils (n = 10) were collected from a formes area and their risk based pollution levels were assessed in the present study using the calculated risk quotient. Concentrations of Pb determined by aqua regia were 295, 258, and 268 mg/kg in B, H and J points and concentrations of Cd were 4.73 and 6.36 mg/kg in G and I points, respectively. These points exceeded the current soil conservation standards. However, risk based pollution levels of the ten points were not able to be calculated because concentrations of Pb and Cd in soil solution were smaller than detection limits or one (i.e., non toxic). It was because heavy metal activity in soil solution was dominant toxicological form to organisms, not a total heavy metal concentration in soil. In addition, heavy metal toxicity was decreased by competition effect of major cations and formation of complex with dissolved organic carbon in soil solution. Therefore, it is essential to consider site-specific factors affecting bioavailability and toxicity for estimating reliable risk of Pb and Cd.

• Review of KIISC
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• v.5 no.1
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• pp.85-100
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• 1995

지난 호에 이어 상대방이 자신이라고 주장한 실체가 정말 그 실체인지를 인증하기 위한 기법을 표준화하는 과제 중의 세번째로 "공개키 알고리듬을 이용한 인증"을 소개한다. 이 과제는 1990년 CD(Committee Draft), 1992년 DIS(Draft for International Standard)가 되었고 1993년에 IS(International Standard)가 되었으며 1998년에 1차 검토가 있을 예정이다.가 있을 예정이다.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.187-190
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• 2002

본 논문에서는 지금까지 소개된 44.1KHz compact disc (CD)에서 48KHz digital audio tape (DAT)로의 표본화율 변환기법들에 대해서 가청 주파수 대역에서 100dB 이상의 dynamic range와 ±5x10­4dB 이하의 리플 크기를 유지할 수 있도록 각 기법들을 재설계하였으며, 메모리 요구량 및 계산량에 대해서 살펴보고자한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.728-730
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• 2003

오늘날 방대한 양의 정보를 관리하고 검색하기 위해 정보를 효율적으로 처리 할 수 있는 방안에 대해서 많은 연구가 진행되고 있다. 본 논문에서는 문서를 구조화하기 위한 방법으로써 XML을 기반으로 하고, 이를 효과적으로 검색하기 위해서 색인기법을 제안하므서 CD-ROM이나 하드 디스크와 Locai 보조 기억 장치에 저장되어 있는 문서 파일을 효율적으로 검색할 수 있도록 한다.