• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.247-248
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• 2012

• 한국대기환경학회지
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• 제31권2호
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• pp.181-194
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• 2015

Spatial-temporal meteorological features of the Ulsan metropolitan region (UMR) were analyzed using observations and high-resolution numerical modeling. Long-term trend analysis (1970~2013) showed a significant increase of $0.033^{\circ}Cyr^{-1}$ in the 5-year moving average temperature, although detailed short-term features varied, whereas wind speed and relative humidity over the same period displayed clear decreases of $-0.007ms^{-1}$ and $-0.29%yr^{-1}$, respectively. These trends indicate the effects of regional climate change and urbanization in the UMR. Seasonal variations averaged for the most recent three years, 2011~2013, showed that temperatures in three different regions (urban/industrial, suburban, coastal areas) of the UMR had similar seasonality, but significant differences among them were observed for a certain season. Urban and industrial complex regions were characterized by relatively higher temperatures with large differences (max.: $3.6^{\circ}C$) from that in the coastal area in summer. For wind speed, strong values in the range from 3.3 to $3.9ms^{-1}$ occurred in the coastal areas, with large differences clearly shown between the three regions in September and October. Diurnal variations of temperature were characterized by pronounced differences during the daytime (in summer) or nighttime (in winter) between the three regions. Results from the WRF modeling performed for four months of 2012 showed large variations in gridaverage temperature and winds in the UMR, which displayed significant changes by season. Especially, a clear temperature rise in the urban center was identified in July ($0.6^{\circ}C$ higher than nearby urban areas), and overall, relatively weak winds were simulated over urban and inland suburban regions in all seasons.

• 대한전자공학회논문지SD
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• 제46권12호
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• pp.24-29
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• 2009

$0.18{\mu}m$ deep n-well 벌크 NMOSFET에서 측정된 차단주파수 $f_T$의 고온종속성을 모델화하기 위해, 측정된 S-파라미터를 사용한 정확한 RF 방법으로 $30^{\circ}C$에서 $250^{\circ}C$까지 전자속도 고온 데이터가 추출되었다. 이러한 추출데이터를 사용하여 개선된 온도종속 전자속도 방정식이 높은 온도의 범위에서 생기는 기존 방정식의 모델링 오차를 없애기 위해 개발되었으며 BSIM3v3 SPICE RF 모델에 구현되었다. 개선된 온도 종속 방정식은 기존 모델보다 $30^{\circ}C$에서 $250^{\circ}C$까지 측정된 $f_T$와 더 잘 일치하였으며, 이는 개선된 방정식의 정확성을 입증한다.

• The Korean Journal of Ceramics
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• 제4권2호
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• pp.136-140
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• 1998

This work demonstrates a method for modeling of electrical conductivity in high-temperature proton-conducting oxides. Total conductivity was calculated assuming that it comprises partial conductivities contributed by protons, oxygen ions and electron holes. From the polt $\sigma_{tot}$ vs. $po_2\;{1/4}$ in wet atmosphere, thermodynamic and kinetic parameters were obtained representing transport properties such as concentration and mobility of the charge-carrying defects. The formulas for the calculation of partial conduction were derived based on the defect structure of HTPCs. Illustrative calculation were made for $SrCe_{0.95}Yb_{0.05}O_{2.975}$ system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.37-39
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• 2003

This paper Presents an effective modeling scheme of high temperature superconducting transformer. So far there were numerical modeling and designs for conventional transformers for various applications. Recently, the interest and the R&D in superconducting technology and devices such as superconducting generator, motor, cable, fault current limiter and transformer have been increased gradually. With those interests, this paper proposes a simulation model of high temperature superconducting transformer using PSCAD/EMTDC, which can be applied to the utility network simulation readily under various system conditions.

• 한국환경과학회지
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• 제9권1호
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• pp.57-64
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• 2000

The sensitivity analysis of two short-term models (ISCST3, INPUFF2.5) is performed to improve the model accuracy. It appears that the sensitivities on the changes of wind speed, stack height and stack inner diameter in the near distance from source, stability and mixing height in the remote distance form source, are significant. Also the gas exit velocity, stack inner diameter, gas temperature and air temperature which affect the plume rise have some effects on the concentration values of each model within the downwind distance where final plume rise is determined. And in modeling for the atmospheric dispersion of point pollutant source INPUFF2.5 can calculate amount, trajectory of puff and concentration versus time at each receptors. So, it is compatible to analyze distribution of point pollutants concentration at modeling area.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.473-473
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• 2011

Group method of data handling neural networks model (GMDH-NNM) is used to estimate daily reference evapotranspiration (ETo) using limited climatic variables such as max temperature ($T_{max}$), min temperature ($T_{min}$), mean wind speed ($W_{mean}$), mean relative humidity ($RH_{mean}$) and sunshine duration (SD). And, for the performances of GMDH-NNM, it consists of training and test performances, respectively. The training and test performances are carried out using daily time series data, respectively. From this research, we evaluate the impact of GMDH-NNM for the modeling of the nonlinear time series data. We should, thus, construct the credible data of the daily ETo data using GMDH-NNM, and can suggest the methodology for the irrigation and drainage networks system. Furthermore, this research represents that the strong nonlinear relationship such as ETo modeling can be generalized using GMDH-NNM.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.600-601
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• 2010

This paper presents the superheater dynamic modeling and parameter estimation for the thermal plant boiler. The temperature control is closely related to the power plant efficiency and boiler life. The dynamic modeling of the superheater and desuperheater is essentially needed and developed by using the heat balance principle. The simulated model outputs are well matched with the actual ones. It is expected that the proposed model is useful for the temperature controller design.

• 마이크로전자및패키징학회지
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• 제20권3호
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• pp.7-10
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• 2013

This study presents an approach to predict insulation resistance failure of multilayer ceramic capacitors (MLCCs) using non-linear modeling. A capacitance aging model created by non-linear modeling allowed for the prediction of insulation resistance failure. The MLCC data tested under temperature-humidity-bias testing conditions showed that a change in capacitance, when measured against a capacitance aging model, was able to provide a prediction of insulation resistance failure.

• 설비공학논문집
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• 제25권1호
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• pp.20-27
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• 2013

Numerical modeling of $CO_2$ water heater was conducted prior to optimal design of medium and large sized $CO_2$ water heater, and the experimental test with small sized $CO_2$ water heater having heat capacity of 4 kW was completed to verify the present numerical model. The present model estimated the experimental data of COP(coefficient of performance), heating capacity, and the hot water outlet temperature within the range of 3% to 8% of mean deviation. As increase of EEV(electric expansion valve) opening area, decreasing of heating capacity and the hot water outlet temperature, and increasing of COP were found in both experimental and numerical investigation.