• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1503-1508
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• 2009

This study applied image processing techniques, constructed to real-time, to thermal infrared camera image. Thermal infrared image data was utilized for hot mapping, cool mapping, and rainbow mapping according to changing temperature. It was histogram image processing techniques so that detected shade contrast function of the thermal infrared image, and the thermal infrared image's edge was extracted to classification of object. Moreover, extraction of temperature from image was measured by using the image information program.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1455-1464
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• 1994

A new and efficient algorithm for the integration of the thermal-elasto-plastic constitutive equation is proposed. While it falls into the category of the return mapping method, the algorithm adopts the three point approximation of plastic corrector within one time increment step. The results of its application to a von Mises-type thermal-elasto-plastic model with combined hardening and temperature-dependent material properties show that the accurate iso-error maps are obtained for both angular and radial errors. The accuracy achieved is because the predicted stress increment in a single step calculation follows the exact value closely not only at the end of the step but also through the whole path. Also, the comparison of the computational time for the new and other algorithms shows that the new one is very efficient.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.788-789
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• 2011

A comprehensive thermo-electromagnetic model has been developed to estimate temperature and electromagnetic distribution in an three-phase induction motor under steady state operation. Electromagnetic modeling enables us to predict thermal dissipation rates by eddy-current loss and copper loss in induction motors. Non-uniform temperature distributions are investigated to account for the strong effect of local temperature build-up on the motor performance and expected life-span. For more accurate thermal modeling purpose, Heat loss mapping method, which is matched up with electromagnetic losses and volumetric heat source, is developed and performed analysis. Heat loss mapping method can be greatly used as a design or diagnostic tool for three-phase induction motors with complex structural electromagnetic fields.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.29-32
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• 2010

공정이 미세화 될수록 프로세서 상에서의 thermal management는 점점 중요해지고 있다. 칩의 온도가 임계 온도를 넘어 손상되거나, 시스템이 불능이 되는 상황을 방지하기 위해 그 동안 많은 기법들이 소개되어 왔다. 하지만 이러한 기법들은 시스템 전체를 끄거나 느려지게 함으로써 상당한 양의 성능 저하를 가져왔다. 이 논문에서는 프로세서의 가장 중요한 Hotspot인 Register File의 온도 관리를 위한 기법으로 Periodic Mapping을 제안하고, 이를 기존의 기법들과 비교해 본다.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2162-2173
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• 2021

In this paper, the coupling of fine-mesh computational fluid dynamics (CFD) thermal-hydraulics (TH) code and neutronics code is achieved using the Ansys Fluent User Defined Function (UDF) for code development, including parallel meshing mapping, data computation, and data transfer. Also, some CFD schemes are designed for mesh mapping and data transfer to guarantee physical conservation in the coupling computation. Because there is no rigorous research that gives robust guidance on the various CFD schemes that must be obtained before the fine-mesh coupling computation, this work presents a quantitative analysis of the CFD meshing and mapping schemes to improve the accuracy of the value and location of key physical prediction. Furthermore, the effect of the sub-pin scale coupling computation is also studied. It is observed that even the pin-resolved coupling computation can also create a large deviation in the maximum value and spatial locations, which also proves the significance of the research on mesh mapping and data transfer for CFD code in a coupling computation.

• Proceedings of the Optical Society of Korea Conference
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• 1999.08a
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• pp.58-59
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• 1999

• Smart Structures and Systems
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• v.22 no.2
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• pp.201-207
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• 2018

This paper proposes a line laser thermography scanning (LLTS) system for multiple crack evaluation on a concrete structure, as the core technology for unmanned aerial vehicle-mounted crack inspection. The LLTS system consists of a line shape continuous-wave laser source, an infrared (IR) camera, a control computer and a scanning jig. The line laser generates thermal waves on a target concrete structure, and the IR camera simultaneously measures the corresponding thermal responses. By spatially scanning the LLTS system along a target concrete structure, multiple cracks even in a large scale concrete structure can be effectively visualized and evaluated. Since raw IR data obtained by scanning the LLTS system, however, includes timely- and spatially-varying IR images due to the limited field of view (FOV) of the LLTS system, a novel time-spatial-integrated (TSI) coordinate transform algorithm is developed for precise crack evaluation in a static condition. The proposed system has the following technical advantages: (1) the thermal wave propagation is effectively induced on a concrete structure with low thermal conductivity of approximately 0.8 W/m K; (2) the limited FOV issues can be solved by the TSI coordinate transform; and (3) multiple cracks are able to be visualized and evaluated by normalizing the responses based on phase mapping and spatial derivative processes. The proposed LLTS system is experimentally validated using a concrete specimen with various cracks. The experimental results reveal that the LLTS system successfully visualizes and evaluates multiple cracks without false alarms.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.555-555
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• 2009

A web GIS based database system of thermophysical property of rocks in Korea is under construction. Rock samples were randomly collected over the whole country and sample spacings were generally 1 to 10 km. Thermal diffusivity, spedific heat, thermal conductivity, specific heat, density and porosity were measured on a collection of 1,560 rock samples in the laboratory. The sampled rocks were classified into igneous, metamorphic and sedimentary rock types and the variables were statistically studied. The thermal conductivity were compared with thermal diffusivity, porosity and dry density to define any correlations and the distribution of thermal conductivity is characterized by the geostatistical analysis. The optimal mapping of thermal conductivity is very useful as a practical design component for any geothermal systems.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.1-8
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• 2016

PURPOSES : This study evaluates the reliability of the patterns of changes in the road surface temperature during winter using a statistical technique. In addition, a flexible road segmentation method is developed based on the collected road surface temperature data. METHODS : To collect and analyze the data, a thermal mapping system that could be attached to a survey vehicle along with various other sensors was employed. We first selected the test route based on the date and the weather and topographical conditions, since these factors affect the patterns of changes in the road surface temperature. Each route was surveyed a total of 10 times on a round-trip basis at the same times (5 AM to 6 AM). A correlation analysis was performed to identify whether the weather conditions reported for the survey dates were consistent with the actual conditions. In addition, we developed a method for dividing the road into sections based on the consecutive changes in the road surface temperature for use in future applications. Specifically, in this method, the road surface temperature data collected using the thermal mapping system was compared continuously with the average values for the various road sections, and the road was divided into sections based on the temperature. RESULTS : The results showed that the comparison of the reported and actual weather conditions and the standard deviation in the observed road surface temperatures could produce a good indicator of the reliability of the patterns of the changes in the road surface temperature. CONCLUSIONS : This research shows how road surface temperature data can be evaluated using a statistical technique. It also confirms that roads should be segmented based on the changes in the temperature and not using a uniform segmentation method.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.274-279
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• 2012

Daegu Solar Power Tower Plant of 200 kW thermal capacity was developed for the first time in Korea, 2011. Measurement of the heat flux distribution is essential to evaluate the solar energy concentrated by reflectors and to design a suitable receiver. The flux mapping technique, which uses a radiometer and a diffuse plate, is common for measurement of the heat flux distribution. Because the solar power tower plant has a wide concentration area, the flux mapping technique using a fixed diffuse plate is difficult to apply. Therefore, the flux distribution in the solar power tower plant should be measured by the flux mapping technique using a small moving bar. In this study, we measured flux distributions with the moving-bar system developed at the KIER solar furnace and evaluated its applicability for the solar power tower plant.