• 한국측량학회지
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• 제18권3호
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• pp.233-240
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• 2000

소하천은 지역주민에게 아름다운 경관과 놀이공간 및 휴식장소를 제공할 뿐만 아니라 중요 용수원이자 배수로로 활용되는 지역주민의 가장 밀접한 생활공간의 일부이며 수변의 각종 식물이나 동물이 인간과 가장 조화롭게 공존하는 공간이라 할 수 있다. 이런 소하천에 대한 정비 계획을 수립하는데 여러 가지의 방향과 모델이 제시 되어왔으나, 소하천은 다양한 변화와 많은 재원이 투입해야 하는 어려움이 있다. 소하천 정비계획은 일반하천의 정비계획과 달리 관할구역내 모든 소하천을 대상으로 일시에 수립해야 하는 계획으로 정비 우선순위 결정이 선행되어야 한다. 현재 소하천 우선순위 결정을 실시한 지역은 아직 미미한 편이며, 처리를 했다 할지라도 처리 작업이 모두 수작업으로 많은 시간이 소요되고 있다. 그러므로 지리정보시스템은 공간 자료의 분석과 관리를 위한 도구로, 소하천에 대한 정비 우선순위 결정을 위해 사용된다면 많은 도움을 줄 수 있을 것이다. 이 연구의 목적은 지형공간정보체계를 사용함으로써 소하천 정비에 있어 효율적인 우선순위 결정을 위한 것으로 소하천의 빈번한 우선순위 결정인자 변화에 신속히 대응할 수 있도록 하였다.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3307-3311
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• 2013

A new fiber optical sensor was developed for the determination of 2,4-dichlorophenol (DCP). The sensor was based on DCP oxidation by oxygen with the catalysis of iron(III) tetrasulfophthalocyanine (Fe(III)PcTs). The optical oxygen sensing film with $Ru(bpy)_3Cl_2$ as the fluorescence indicator was used to determine the consumption of oxygen in solution. A lock-in amplifier was used for detecting the lifetime of the oxygen sensing film by measuring the phase delay change of the sensor head. The different variables affecting the sensor performance were evaluated and optimized. Under the optimal conditions (i.e. pH 6.0, $25^{\circ}C$, Fe(III)PcTs concentration of 0.62 mg/mL), the linear detection range and response time of the sensor are $1.0{\times}10^{-6}-9.0{\times}10^{-6}$ mol/L and 250 s, respectively. The sensor displays high selectivity, good repeatability and stability, and can be used as an effective tool in analyzing DCP concentration in practical samples.

• The Korean Journal of Physiology and Pharmacology
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• 제10권6호
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• pp.349-354
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• 2006

The aromatic hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the biological and toxicological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related chemicals. The application of recombinant reporter plasmid such as the firefly luciferase gene has proven to be a very effective method to detect these chemicals. The bioassay system, CALUX, is sensitive in directly detecting AhR-agonists from a variety of environmental and biologic materials. However, responses of the AhR-dependent bioassays are dependent on the cell types used. Thus, we developed a sensitive bioassay using the recombinant mouse hepatoma cell (Hepa1c1c7) for the determination of dioxins. The recombinant cell line was stably transfected with firefly luciferase reporter gene (pGudLuc1.1). The transfected cells showed the highest induction of luciferase activity at 4.5 hr and a decrease beyond this time point. The system showed the highest sensitivity of detection ever reported. Upon TCDD exposure cells showed 2 fold increase at 10 pM and 7 fold increase at 100 pM, respectively. The passage number after the transfection played an important role in the sensitivity. The increase of passage number tended to increase the sensitivity of the cells up to 15. The media without phenol red showed a higher induction rate than with phenol red, suggesting the preferable use of phenol red-free media for the bioassay. Since each of the assays has unique characteristics that make them suitable for some screening applications and not others, development of sensitive bioanalytical methods based on a variety of cellular systems in a key to the successful determination of dioxins. The bioassay system developed in this study will contribute to further development of successful screening the AhR agonists among the environmental mixture. In addition, the rapid and sensitive nature of this cellular system can be applied as a valuable tool to screen the dioxin-like moieties among the prodrugs at the initial stage, thereby expediting the new drug discovery.

• 한국지반공학회논문집
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• 제24권4호
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• pp.115-123
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• 2008

지반과 같은 다층으로 구성된 시스템을 통과하여 전파되는 파의 분산특성은 표면파 지반조사에서 매우 중요한 요소이다. 이러한 표면파의 분산곡선(주파수위상속도 곡선)은 크로스 파워 스펙트럼에 의해 결정되는 위상 스펙트럼을 사용하여 쉽게 결정할 수 있다. 그러나 크로스 파워 스펙트럼에 의해 결정되는 분산곡선은 현장에 항상 존재하는 잡음에 의해 쉽게 손상되며, 손상된 분산곡선을 사용하는 경우 잘못된 조사 결과를 도출하기도 한다. 본 논문에서는 이러한 기존 방법의 문제점을 해결하고자 하모닉 웨이브릿 변환을 이용한 새로운 위상 스펙트럼 결정방법을 제안하고 이를 분산곡선을 결정에 적용하였다. 제안된 방법은 효과적으로 현장에 존재하는 배경잡음의 효과를 제거할 수 있다. 제안된 방법의 타당성을 검증하기 위하여, 지반을 모사한 다층구조에 대해 수치모의실험을 수행하였다. 수치모의실험을 통하여 제안된 방법이 심한 잡음조건하에서도 효과적으로 신뢰할 수 있는 위상 스펙트럼과 분산곡선을 결정할 수 있음을 볼 수 있었으며, 이를 통하여 제안된 방법의 타당성을 확인하였다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2002년도 제3회 최신 분말제품 응용기술 Workshop
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• pp.25-37
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• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• 디지털융복합연구
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• 제13권10호
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• pp.579-586
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• 2015

어린 초등학교 2~6학년 학생들을 대상으로 과학적이며, 체계적인 훈련을 지원하기 위하여 전국 권역별 대학교를 중심으로 체육영재센터를 운영하고 있다. 이를 위하여 초등학생 2~6학년을 대상으로 기초체력 및 잠재력 검사를 통해 선발운영토록 한다. 하지만 현재 시행 중인 이러한 선발방법은 체육영재 학생들에 대한 질적 평가는 포함되어 있지 않으며, 특히 측정시점에서의 체력, 체격요인에 의하여 상위 순위에 의하여 체육영재를 선발하는 방식으로써 대상 학생들에 대한 잠재적 능력의 평가 및 내재적 평가는 포함되어 있지 않다. 이에 본 연구에서는 윤영길(2011)의 경기지능을 바탕으로 체육영재의 잠재력을 평가할 수 있는 관찰방법에 기초한 영재성 판별 도구를 개발하고자 하였다. 이를 위하여 2회에 걸친 전문가 협의를 통해 체육영재 판별을 위한 하위요인을 추출하였으며, 추출된 하위요인을 바탕으로 현장 지도자들의 관찰방법에 기초한 훈련지능, 학습능력, 실천지능의 요인별 16개의 평가문항을 개발, 제시하였다. 제시된 평가문항은 체육영재 학생들의 질적 평가에 도움이 될 것이며, 아울러 체육영재 선발을 위한 내재적 평가 방법으로의 활용도 기대해 본다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1125-1125
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• 2001

Micro-scale test methods are producing small-sample size where the conventional physical and chemical tests can not be used (high standard deviation, uncertain sampling conditions, low repeatability). Different small-scale test methods were developed recently for determination of physico-chemical, functional, rheological properties of wheat or wheat dough using miniaturized instruments with sophisticated sample preparation/handling and mechanics (RVA, 2 g mixograph, micro-Z-arm mixer, small-scale noodle maker, micro-baking method etc.). The small-scale methodologies can be used as basic research tools or as technology supported measurements and can be also essential in the early selection for quality traits in breeding programs. The milling as a sample preparation step is essential procedure providing good quality flour or semolina samples from small amount of grain (5-10 g) in a reproducible and reliable way. The aim of present study was to use NIR as quality control tool, and to evaluate the recently developed and manufactured micro-scale lab mill (FQC-2000) produced by Inter-Labor Co. Ltd., Hungary. The milling characteristics of the new instrument were compared to other laboratory mills and the effects of milling action on the chemical composition of fractions were analysed. The fractions were tested with both chemical and near infrared spectroscopic methods. The micro-scale milling resulted significantly different yields, particle size distributions and different fractions from compositional point of view. The near infrared spectra were sensitive enough to distinguish the fractions obtained by different milling procedures. Quantitative NIR calibration equations were developed and tested in order to measure the chemical composition of characteristic milling fractions. Special qualification procedure the PQS (Polar Qualification System) method was used for detecting the differences between fractions obtained by macro and micro-milling procedures. The results and the limitations of PQS method in this application will be discussed.

• 대한환경공학회지
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• 제32권5호
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• pp.455-460
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• 2010

본 연구에서는 프탈레이트 화합물 측정 시 시료채취 및 분석과정 증에서 야기될 수 있는 공시료의 오염여부를 평가하고 clean-up 절차와 같은 적절한 개선 방안을 제시하였다. 실험도구 및 시료채취 매체에 대한 공시료를 평가한 결과 많은 종류의 실험기구 및 장치에서 DBP와 DEHP가 잔존하는 것으로 나타났다. 따라서 실험도구는 반드시 전처리하여 사용해야 하며, 이후 공시료 보정이 수반되어야 한다. 또한 본 연구에서 제시한 clean-up 방법을 통해 불순물이 많이 제거되었으며, GC/MS를 이용한 정성?정량분석에서 정도개선에 효과적인 것으로 나타났다.

• 한국자동차공학회논문집
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• 제20권4호
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• pp.46-51
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• 2012

Injection pressure, an important factor in filling process, should be minimized to enhance injection molding quality. Injection pressure can be controlled by valve gate open timing. In this work, we decided the valve gate open timing to minimize the injection pressure. To solve this design problem, we integrated MAPS-3D (Mold Analysis and Plastic Solution-3Dimension), a commercial injection molding CAE tool, to PIAnO (Process Integration, Automation and Optimization), a commercial PIDO (Process Integration, and Design Optimization) tool using the file parsing method. In order to reduce computational cost, we performed an approximate optimization using meta-models that replaced expensive computer simulations. At first, we carried out DOE (Design of Experiments) using OLHD (Optimal Latin Hypercube Design) available in PIAnO. Then, we built Kriging models using the simulation results at the sampling points. Finally, we used micro GA (Genetic Algorithm) available in PIAnO. Using the proposed design approach, the injection pressure has been reduced by 13.7% compared to the initial one. This design result clearly shows the validity of the proposed design approach.

• 한국농공학회논문집
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• 제54권6호
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• pp.53-63
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• 2012

The objectives of this study were to develop a linked watershed-waterbody modeling system and to assess the impacts of indirect wastewater reuse on irrigation water quality. The Osan stream watershed within Gyeonggi-do of South Korea was selected for this study. The linked modeling system was composed of the SWAT (Soil and water assessment tool) and QUALKO2 models. The SWAT model was calibrated and validated using the stream discharge and water quality data from 2010 to 2011. Runoff and non-point source pollutants from each subbasin and stream discharge from 1980 to 2009 were simulated by the SWAT model and applied to the QUALKO2 model. The QUALKO2 model was calibrated and validated under the conditions of low water and normal discharges, respectively. Finally, The 10-day irrigation water quality from April to September was simulated. The statistical measures of coefficient of determination ($R^2$), reliability index (RI), and efficiency index (EI) were used to evaluate the system performance. The $R^2$, RI and EI values ranged from 0.5 to 1.0, 1.03 to 1.92, and -35.03 to 0.95, respectively. The 10-day irrigation water quality showed the concentrations of BOD and coliform exceeded the water quality guidelines for wastewater reuse. The linked modeling system can be a useful tool to estimate non-point source pollutant loads in watershed and to control the water quality of effluent from a wastewater treatment plant and irrigation water in the downstream waterbody.