• 제목/요약/키워드: simulated field condition

검색결과 182건 처리시간 0.034초

대형 강의실의 실내 열환경 실측 및 컴퓨터시뮬레이션 비교 연구 (Field Measurements and CFD Simulations of Indoor Thermal Environments in the Assembly Hall)

  • 윤재옥
    • KIEAE Journal
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    • 제4권3호
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    • pp.179-186
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    • 2004
  • The evaluation of the indoor environment of the Assembly Hall in the University, which is designed to be a large space, requires efficient design of its heating system that takes into consideration natural convection and the characteristics of the occupant's spaces. Indoor thermal environment was measured in the field and simulated with CFD code. The estimations of temperature distribution and indoor airflow distribution must be carried out simultaneously, as the thermal stratification is induced by natural convection flows. In order to simulate the even distribution of factors affecting the indoor environment, including temperature and airflow, Phoenics is used. The turbulent flow model adopted is the RNG k- model. The inlets and outlets of the air-conditioning systems, material and thermal properties, and the size of the test room ($35m{\times}18m{\times}10m$) are used for the simulation. Since the Assembly Hall is symmetric, half of the space is simulated. A Cartesian grid is used for calculation and the number of grids are respectively $60{\times}45{\times}35$. The results of the computer simulation during winter conditions are compared with the measurements at the typical points in the assembly hall with the heating system. After evaluating the results of the computer simulations, the methods of the heating system and layout are suggested.

GIS내 금속이물 존재시 절연특성 (The Insulation Characteristics by Conducting Particle in GIS)

  • 조국희;김재철;곽희로
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 춘계학술대회 논문집 전기설비전문위원
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    • pp.105-108
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    • 2004
  • This paper describes the influence of conducting particle in the coaxial cylindrical electrodes under alternating voltage condition investigated using breakdown electric field and electro magnetics simulation method. Simulated particle-location in GIS chamber were the particle on electrode, the particle on enclosure and free moving particle. As results, it was founded that in case of breakdown electric field of the GIS chamber, breakdown electric field of particle on electrode was the lowest, that of free moving particle was middle and that of particle on enclosure was the highest. And in case of the electric field analysis with particle locations, electric field of particle on electrode was the highest that of lifted particle was middle and that of particle on enclosure was the lowest. This results can offer a practical reference ra the insulation design of domestic GIS.

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구형 유전체비드를 가지는 단층절연방전관의 수(水)오존농도측정 및 전계분포 시뮬레이션 (The measurement of Ozone Concentration and Simulation of Electric Field Distribution at Dielectric Tube of one Layer with Globular Dielectric in Water)

  • 이동훈;박재윤;박홍재;고희석;이현수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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    • pp.44-47
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    • 2003
  • In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric($ZrO_2$) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], $ZrO_2(\varepsilon_r:10)$ and one glass plate of thickness(2[mm]), $\varepsilon_r$(10) as electrode. The discharge gap was 8[mm]. To get more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, ozone was measured higher dissolved ozone in water at condition of water rate(l[l/min]) and injector than condition of non-injector or 2~3[l/min].

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구형 유전체비드를 가지는 단층절연방전관의 $H_2O_2$ 농도 측정 및 전계분포시뮬레이션 (The measurement of $H_2O_2$ Concentration and Simulation of Electric Field Distribution at Dielectric Tube of one Layer with Globular Dielectric in Water)

  • 박홍재;박재윤;이동훈;고희석;이현수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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    • pp.40-43
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    • 2003
  • In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric(glass) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], glass(${\varepsilon}_r$:5) and one glass plate of thickness(2[mm]), ${\varepsilon}_r$(5) as electrode. The discharge gap was 8[mm). Toget more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, $H_2O_2$ was measured higher generated $H_2O_2$ in water at condition of water rate(1[l/min]) and injector than condition of non-injector or 2-3[l/min])

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TOPLATS 지표해석모형 기반의 고해상도 수문성분 평가 (Evaluation of High-Resolution Hydrologic Components Based on TOPLATS Land Surface Model)

  • 이병주;최영진
    • 대기
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    • 제22권3호
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    • pp.357-365
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    • 2012
  • High spatio-temporal resolution hydrologic components can give important information to monitor natural disaster. The objective of this study is to create high spatial-temporal resolution gridded hydrologic components using TOPLATS distributed land surface model and evaluate their accuracy. For this, Andong dam basin is selected as study area and TOPLATS model is constructed to create hourly simulated values in every $1{\times}1km^2$ cell size. The observed inflow at Andong dam and soil moisture at Andong AWS site are collected to directly evaluate the simulated one. RMSEs of monthly simulated flow for calibration (2003~2006) and verification (2007~2009) periods show 36.87 mm and 32.41 mm, respectively. The hourly simulated soil moisture in the cell located Andong observation site for 2009 is well fitted with observed one at -50 cm. From this results, the cell based hydrologic components using TOPLATS distributed land surface model show to reasonably represent the real hydrologic condition in the field. Therefore the model driven hydrologic information can be used to analyze local water balance and monitor natural disaster caused by the severe weather.

SOI(Silicon-on-Insulator) 소자에서 후면 Bias에 대한 전기적 특성의 의존성 (Dependence of Electrical Characteristics on Back Bias in SOI Device)

  • 강재경;박재홍;김철주
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 1993년도 춘계학술발표회
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    • pp.43-44
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    • 1993
  • In this study SOI MOSFET model of the structure with 4-terminals and 3-interfaces is proposed. An SOI MOSFET is modeled with the equivalent circuit considered the interface capacitances. Parameters of SOI MOSFET device are extracted, and the electrical characteristics due to back-bias change is simulated. In SOI-MOSFET model device we describe the characteristics of threshold voltage, subthreshold slope, maxium electrical field and drain currents in the front channel when the back channel condition move into accmulation, depletion, and inversion regions respectively.

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주변 상황에 적응하는 LVQ 지능 시스템 (Adaptive LVQ Intelligent System for Perimeter Condition)

  • 엄기환
    • 한국정보통신학회논문지
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    • 제3권3호
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    • pp.627-638
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    • 1999
  • In this paper, the system with an artificial intelligent that is able itself to adjust the perimeter condition of the plant is presented. The proposed intelligent system is composed of two learning vector quantization(LVQ) networks, which are used mostly in the field of the pattern recognition and signal processing. From the external condition of the plant, the first LVQ network recognizes the pattern of the sensed signal and the second LVQ network judges synthetically user's characteristics and performs learning. The controller controls the plant using the reference value, which is the output value of the synthetic judgement part. In order to verify the usefulness of the proposed method, we simulated the two LVQs are implemented for the artificial intelligent illuminator as well as being carried out computer simulations. We implemented the proposed artificial intelligent illuminator and perform the experiment.

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전기집진 기제를 조합시킨 DPF용 금속 폼 필터의 여과 특성 (Filtration Characteristics of Metal Foam Filters for DPF Combined with Electrostatic Precipitation Mechanism)

  • 박석주;이동근;김진현;조규백;김홍석;정용일
    • 한국자동차공학회논문집
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    • 제15권2호
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    • pp.151-158
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    • 2007
  • Filtration studies, using simulated test nanoparticles or diesel nanoparticles, have been performed about Inconel foam filters for DPF combined with electrostatic precipitation. The simulated test particles were synthesized by laser ablation in the nitrogen atmosphere at the standard condition. The diesel particles were exhausted from the diesel engine driven on the condition of idle or load mode. Filtration efficiency of the metal foam filter is very low because most of particles are penetrated through the large pores of filter. However, the efficiency was considerably improved by applying the electric field to the filter and/or charging the nanoparticles. Nevertheless, the pressure drop of filter hardly increased because the filter-pores were not clogged by deposited particles and kept open.

일체형 로켓-램제트 모드 천이 및 불안정 연소 유동장 해석 (Numerical Analysis on the Mode Transition of Integrated Rocket-Ramjet and Unstable Combusting Flow-Field)

  • 고현;박병훈;윤웅섭
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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    • pp.334-342
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    • 2005
  • A numerical analysis is performed using two dimensional axisymmetric RANS (Reynolds Averaged Navier-Stokes) equations system on the transition sequence of the Integrated Rocket Ramjet and the unsteady reacting flow-field in a ramjet combustor during unstable combustion. The mode transition of an axisymmetric ramjet is numerically simulated starting from the initial condition of the boost end phase of the entire ramjet. The unsteady reacting flow-field within combustor is computed for varying injection area. In calculation results of the transition, the terminal normal shock is occurred at the downstream of diffuser throat section and no notable combustor pressure oscillation is observed after certain time of the inlet port cover open. For the case of a small injection area at the same equivalence ratio, periodic pressure oscillation in the combustor leads to the terminal shock expulsion from the inlet and hence the buzz instability occurred.

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합리적 관개용수량 산정에 관한 연구 (Study on the Effective Calculation Method of Irrigation Water in a Paddy Fields Area)

  • 이용직;김선주;김필식;주욱종;양용석
    • 한국농공학회논문집
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    • 제48권3호
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    • pp.11-20
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    • 2006
  • In this study, the actual water management were investigated and analyzed on site for effective use of the paddy irrigation water. And this study is tried to analyze the difference between simulated irrigation water according to current design method and actual water supply in experimental reservoirs. The reservoirs in Idong, Yongdeok and Misan, which are managed by Korea Rural Community & Agriculture Corporation, were selected fur field investigation. The purpose of this study is to suggest an improved method for irrigation water calculation through quantitative and periodical analysis considering the difference between design and actual field condition.