• Journal of Environmental Impact Assessment
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• v.9 no.1
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• pp.61-74
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• 2000

This study compares the results of environmental impact assessment with the results of post-environmental investigation, using the case of Taean thermal power plant construction. The atmospheric and water qualities were not greatly changed before and after the construction of the power plant. However, the site of the highest concentration predicted by the atmospheric quality modeling in environmental impact assessment was different from that after operation of 4 power plants. There was also a difference in the diffusion range of thermal discharge water between the measured result(1km) and the predicted value(1.5km) with the model. Thus, environmental impact evaluation should be based on long-term (more than a year) environmental monitoring data. For the modeling of atmospheric quality and numerical thermal discharge water diffusion, appropriate models for each plant should be selected and the numerical modeling should be accompanied by computer simulation, wind tunnel test, etc. Moreover, environmental evaluation should focus more on the degree of impact on surroundings than the prediction of changes in surroundings caused by operation of plants.

• Ecology and Resilient Infrastructure
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• v.7 no.1
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• pp.43-52
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• 2020

For investigating restriction in the use of computer modeling results without adjusting them with measured data, this study analyzed and compared microclimatic aspects and human thermal sensation between in situ measurement and computer modeling using ENVI-met in and around a small urban park of downtown Changwon in May, 2012. In the results, ENVI-met underestimated air temperatures and wind speeds than the measured ones and overestimated relative humidities. In the radiation analysis, ENVI-met overestimated solar radiation from the sky hemisphere and terrestrial radiation from the ground hemisphere and underestimated terrestrial radiation from the sky hemisphere. Also, the differences of mean radiant temperatures with the measured ones reached up to 19.6℃ which could create an 1.2 PMV difference. ENVI-met overestimated up to 2.3 PMV and 4℃ UTCI at 12:00. The difference was shown clearly in PMV than in UTCI. Therefore, when computer modeling is used in urban microclimate and human thermal sensation (comfort) studies the modeling results should be compared with measured data and adjusted adequately to adopt the results to urban and landscape planning and design.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.6
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• pp.698-702
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• 2016

Thermal imager is now regarded as one of the key observation devices for ISR activities and getting important more and more. As other detectors, however, the thermal detectors also have maximum input and therefore they will be saturated if the input IR energy exceeds the allowed range. The saturation in the thermal detector makes it impossible to distinguish the target from background, as a result, the thermal imager does not perform its own mission anymore. In order to get an insight related with the image saturation, this paper develops a saturation model for a thermal imaging system, not a thermal detector. The proposed modeling starts from analyzing the specification of a thermal imager. Coupled with the characteristic parameters of the object, the saturation model can be used to predict the distance on which the detector is saturated. The proposed saturation model prove its validity by applying it for the case of observing a flash-bang.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.81-92
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• 1997

This paper presents the results from the comparison analysis and evaluation between the air pollutant dispersion modeling results and the observation data in the area within a 10 km radius from the Boryong thermal power plants. The observation data used in this study were the air pollutant concentrations which had been continuously measured from 8 locations around the Boryong power plants by TMS(tele-monitoring system) for 3 months from September to November, 1996. The short-term and long-term predictions were carried out using ISC3 model and LPDM(Lagrangian Panicle Dispersion Model). The results of ISC3 modeling in a short-term showed highly as 0.7 in a correlation coefficient, but in a long-term showed just 0.54. On the other hand, LPDM showed 0.78 in a correlation coefficient for a long-term, but in a short-term showed highly value than the observation concentrations.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1457-1462
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• 2017

Unsteady thermal processes in storage containers with spent nuclear fuel were modeled. The daily fluctuations of outer ambient temperatures were taken into account. The modeling approach, which is based on the solving of conjugate and inverse heat transfer problems, was verified by comparison of measured and calculated temperatures in outer channels. The time delays in the reaching of maximal temperatures for each spent fuel assembly were calculated. Results of numerical investigations show that daily fluctuation of outer temperatures does not have a large influence on the maximal temperatures of stored spent fuel, so that fluctuation can be neglected and only daily average temperature should be considered for safety estimation using the "best estimation" approach.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.49-55
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• 2016

Nowadays there are magnetic sensors in a wide variety of equipment such as computers, cars, airplanes, medical and industrial instruments. In many of these applications the magnetic sensors offer safe and non-invasive means of detection and are more reliable than other technologies. The electric current in a conductor generates a magnetic field detected by this type of sensor. This work aims to define a package dedicated to an electrical current sensor using a MTJ (Magnetic Tunnel Junction) as a sensing device. Four different proposals of packaging, three variations of the chip on board (CoB) package type and one variation of the thin small outline package (TSOP) were analyzed by COMSOL modeling software by simulating a brad range of current injection. The results obtained from the thermal and magnetic analysis has proven to be very important for package improvements, specially for heat dissipation performance.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1784-1792
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• 2001

Numerical analysis on a parallel flow heat exchanger(PFHE) is performed using 2 dimensional turbulent porous modeling. This modeling can consider three-dimensional configuration of passage (flat tube with micro-channels), and the stability and accuracy of numerical results are improved. The geometrical parameters(e.g., the position of separators, inlet/outlet, and porosity of passages of a PFHE) are varied in order to examine the flow and thermal characteristics and flow distribution of the single phase multiple passages system. The flow non-uniformities along the paths of the PFHE are observed to evaluate the thermal performance of the heat exchanger. The location of inlet affects the heat transfer, and the location of outlet affects the pressure drop. The porosity with the optimum thermal performance is around 0.53.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1098-1100
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• 1993

In this paper, We found the thermal characterstic of impulsed magnetizing fixture system through the SPICE modeling and investigated the applied possibility in application aspects. As the detailed thermal characteristic of magnetizing fixure can be obtained, the efficient design of the magnetizing fixture which produce desired magnet will be possible using our thermal modeling. The purpose of this work is to compute the temperature increasing for different magnetizing conditions. The method uses multi-lumped model with equivalent thermal resistance and thermal capacitance. The model ing and experimental results are in close agreement.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.91.2-91
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• 2002

$\textbullet$ Machine tools $\textbullet$ Thermal distortion compensation $\textbullet$ Independent component analysis $\textbullet$ Temperature variable reduction $\textbullet$ Thermal distortion modeling $\textbullet$ Hardware Implementation $\textbullet$ Experiments

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.3
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• pp.119-125
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• 2013

IInsulation material is generally used for preventing heat loss from heat transport fluids, and water absorption severely reduces the insulation property. The purpose of this study is to evaluate the amount of water absorption supplied by the pouring method and spraying method, to investigate the effects of water absorption on the thermal conductivity of an insulation material, and modeling the relation between water absorption and thermal conductivity. E-glass, a kind of glass fiber, and HYPERLITE, mainly composed of pearlite, are selected, to compare hygroscopic and insulation properties. E-glass is found to have much higher water absorptivity, compared to HYPERLITE. The thermal conductivity of the water-absorbed E-glass is increased by more than 150%, compared to that of no absorption, while variation of the thermal conductivity of HYPERLITE with water absorption is insignificant. A three-stage model of water absorption for thermal conductivity is developed, and the modeling results are found to be in good agreement with the experimental data.