• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.381-384
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• 2002

The purpose of this study is to construct an Environment Database Management System (EDMS) for the Saemangeum watershed based on the linkage of Water Quality Model, i.e. QUALKO and WASP model, and GIS database to estimate water quality effectively in this area. There are two major river systems on this study area, the Mangyeong and the Dongjin rivers. Input data are automatically generated through the calculation of the pollutant loading and inflow concentration from the point and non-point sources. The developed system is composed of three different phases, such as pre-process, model performance and post-process. The Model performance is supported by the database at pre-process phase and model performance results were shown in the graphs and attribution data at post-process phase. The measured data from the Mangyeong and the Dongjin rivers are used to evaluate the applicability of EDMS. The EDMS shows higher reliability, and it is expected to contribute to the effective management and improvement of water quality modeling in the Saemangeum watershed since the system reduces complications of using a model in DOS operating environment and increases the accuracy of water quality analysis.

• Progress in Superconductivity
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• 제12권2호
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• pp.110-113
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• 2011

We have grown a Nb/Gd bilayer on a$SiO_2$/Si substrate by using a DC magnetron sputtering system, which was fabricated in situ with silicon stencil masks. In order to investigate proximity effect of the Nb/Gd bilayer, we used a planar tunnel junction with an AlOx tunnel barrier by oxidizing the Al ground electrode at the bottom. A $Co_{60}Fe_{40}$ backing of Al was deposited so as to reduce the superconductivity of the Al, ensuring a normal counterelectrode. With a 50-nm-thick Nb layer, we have measured dI/dV (dynamic conductance) by varying the thickness of Gd, which can reveal the density of states (DOS) of the Nb/Gd bilayer as a function of the Gd thickness resulting from the proximity effect of a superconductor/ferromagnet bilayer (S/F). The SF proximity effect in Nb/Gd will be discussed in comparison to our previous results of the CoFe/Nb, Ni/Nb and CuNi/Nb proximity effect; Gd is expected to show different effects since Gd has f-electrons, while CoFe, Ni, and CuNi have only d-electrons. Our studies will focus on the triplet correlation in a superconducting pair.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.25-30
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• 2008

본 연구에서는 Visual C++프로그램을 이용하여 램젯엔진시뮬레이션을 위한 코드를 생성하였다. 연구에 사용되어진 램젯엔진은 이상적인모델로 가정하였다. 우선, Visual C++에의해 만들어진 GUI프로그램을 이해하기위해 기초이론을 설명하였다. 주변에서 흔히 구할수 있고, 사용이 용이하며, 빠른계산이 가능한 Visual C++프로그램은 특히 GUI프로그램을 DOS Mode에서도 사용할 수 있게 해준다. GUI프로그램은 엔진흡입구의 초기입력값만 넣어주면, 나머지 스테이션의 초기입력값은 이 프로그램에 의하여 자동으로 계산되어진다. 이 프로그램의 결과는 널리사용되어지고 있는 상형툴인 GASTURB9의 결과와 비교하여 타당성을 검증하였다.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.819-826
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• 2020

The method of the Laplace transform has been used to obtain an analytical solution of the three-dimensional steady state advection diffusion equation for the airborne radionuclide release from any nuclear installation such as the power reactor in an area source. The present treatment takes into account the removal of the pollutants through the nuclear reaction. We assume that the pollutants are emitted as a constant rate from the area source. This physical consideration is achieved by assuming that the vertical eddy diffusivity coefficient should be a constant. The prevailing wind speed is a constant in 𝑥- direction and a linear function of the vertical height z. The present model calculations are compared with the other models and the available data of the atmospheric dispersion experiments that were carried out in the nuclear power plant of Angra dos Reis (Brazil). The results show that the present treatment performs well as the analytical dispersion model and there is a good agreement between the values computed by our model and the observed data.

• 한국환경보건학회지
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• 제34권2호
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• pp.175-182
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• 2008

This study investigates the optimal conditions for electrogenerated hydrogen peroxide production and the application of the electro-Fenton process using DSA electrodes. The influences of parameters for the hydrogen peroxide generation such as electrode materials, electrolyte concentration, current, pH, air flow rate and electrode distance were investigated using a laboratory scale batch reactor. The relative performance for hydrogen peroxide generation of each of the six electrodes is : Ru-Sn-Ti > Ru-Sn-Sb > Ru > Ir > Pt > Sn-Sb. Optimum NaCl dosage, current and air flow rate were 2.0 g/l, 12.5 A and 2 l/min, respectively. When the pH is low, hydrogen peroxide concentration was high. Electrode distance dos not effect to a hydrogen peroxide generation. A complete color removal was obtained for RhB (200 mg/l) at the 8 min mark of the electro-Fenton process under optimum operation conditions of $Fe^{2+}$ 0.105 g/l and 5.0 A. The electro-Fenton process increased initial reaction and decreased final reaction time. However the effect was not high.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1208-1211
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• 2008

We study the amorphous In-Ga-Zn-O thin-film transistors (TFTs) properties under monochromatic illumination ($\lambda=420nm$) with different intensity. TFT off-state drain current ($I_{DS_off}$) was found to increase with the light intensity while field effect mobility ($\mu_{eff}$) is almost unchanged; only small change was observed for sub-threshold swing (S). Due to photo-generated charge trapping, a negative threshold voltage ($V_{th}$) shift is also observed. The photofield-effect analysis suggests a highly efficient UV photocurrent conversion in a-IGZO TFT. Finally, a-IGZO mid-gap density-of-states (DOS) was extracted and is more than an order lower than reported value for a-Si:H, which can explain a good switching properties of the a-IGZO TFTs.

• Spatial Information Research
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• 제2권2호
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• pp.107-116
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• 1994

코로플레스 지도는 지리사상의 지역간 분포 특성을 시각적으로 표현하는 지도이다. CMS는 코로플레스 지도 제작 프로그램으로 1988년에 처음 개발되었다. 본 연구에서는 최근 변화된 컴퓨터 기술과 사용자 환경을 고려하여 이에 적합한 CMS ll를 개발하였다. CMS ll는 IBM PC AT또는 상위 기종에서 실행되며 DOS 5.0 이상의 운영환경과 최소 640KB 이상의 메모리가 필요하다. 그래픽 해상력과 색상을 고려하여 그래픽보드로 VGA를 사용하고 고해상도의지도를 출력하기 위해 HP 호환의 레이저 ? 프린터를 지원한다. 코로플레스 지도를 효과적으로 디자인하기 위해 메뉴와 지도의 제목과 범례 등을 한글화하였고 한자의 사용도 가능하도록 제작하였다. 속성자료의 호환을 위해 DBF형식을 이용하였다.

• 대한가정학회지
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• 제32권5호
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• pp.55-66
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• 1994

The aim of this study is to propose the reasonable method of evaluation on the value of the life-time household work. for homemaker claim her share in the matrimonial property in relation to her life-time household work and to provide the basic data to measuring proper compensation for homemaker and calculating of the donation tax and inheritance tax amount. Tom compare the difference of the method of evaluation on the value of the life-time household work is evaluted by three methods: the model of the life-time household work which is reflected major variables in the FLC frame work marital stage, total marital period. The major findings are as follows: 1) Among the three evaluation me？ The method of Total marital period is evaluatied the lowest value of the life-time household work. 2) The evaluation method of marital stage is more resonable method than the method of total marital period habe a convenience of evaluation but it dos'nt reflected major variables which influence the value of life-time household work. 3) the most resonable method of evaluation on the value of the life-time household work is revealed the model of the life-time household work which is reflected major variables in the FLC frame work the age of first and last offspring marital period.

• 대한기계학회논문집B
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• 제28권9호
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• pp.1066-1074
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• 2004

With a diode corona charger, which is a component of ELPI(Electrical Low Pressure Impactor), aerosol particles are charged to make electrical detection possible before they are collected by the impactor. We designed and evaluated two cylindrical corona chargers, each of which had a central corona needle electrode. For the performance evaluation of each corona charger the polydisperse dioctyl sebacate(DOS) particles, with diameters of 0.1∼0.8 $\mu$m and NaCl particles, smaller than 0.1$\mu$m, were used. The particles were then led through an electrostatic classifier (TSI model 3081) to classify monodisperse aerosol with minimal size deviation. After evaluating the wall loss of the particles in the corona charger, we measured the product of penetration and number of charges, Pㆍn, to evaluate the corona charger efficiency at high positive voltages of 4, 5, 6 kV.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1417-1422
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• 2003

An electrical cascade impactor is a multistage impaction device to separate airborne particles into aerodynamic size classes using electrical method. We designed a real-time three-stage electrical low-pressure impactor, which is proper to nanometer sized environmental aerosols. Performance evaluation was carried out for stage 1 and 2. The monodisperse liquid dioctyl sebacate (DOS) particles were generated using condensation-evaporation followed by electrostatic classification using DMA (differential mobility analizer) for particles with diameters in the range of $0.04{\sim}0.8{\mu}m$. The evaluation of the electrical impactor is based on the use of two electrometers, one connected to the impaction plate of the impactor, and the other to the faraday cage as backup filter. The results showed that the experimental 50% cutoff diameters in the operation pressure were 0.53 and $0.12{\mu}m$ for stage 1 and stage 2. The effect of operation pressure on the cutoff diameter and the steepness of collection effcieicy curves is investigated.