• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.1
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• pp.41-49
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• 2022

Recently interests on the application of thermal cameras have increased with the advance of image analysis technology. Aside from a simple image acquisition, applications such as digital twin and thermal image management systems have gained popularity. To this end, we studied the effect of emissivity on the DN (Digital Number) value in the process of derivation of a relational expression for converting DN to an actual surface temperature. The DN value is a number representing the spectral band value of the thermal image, and is an important element constituting the thermal image data. However, the DN value is not a temperature value indicating the actual surface temperature, but a brightness value indicating high and low heat as brightness, and has a non-linear relationship with the actual surface temperature. The reliable relationship between DN and the actual surface temperature is critical for a thermal image processing. We tested the relationship between the actual surface temperature and the DN value of the thermal image, and then the radiation adjustment was performed to better estimate actual surface temperatures. As a result, the relation graph between the actual surface temperature and the DN value similarly show linear pattern with the relation graph between the radiation-controlled non-contact thermometer and the DN value. And the non-contact temperature after adjusting the emissivity was closer to the actual surface temperature than before adjusting the emissivity.

• Journal of Radiation Protection and Research
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• v.23 no.2
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• pp.115-121
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• 1998

Adsorption characteristics of the radionuclides and stable elements on AMP and $MnO_2$ in the seawater have been investigated. The adsorption yield of AMP was 97.5% for $^{137}Cs$, 11.8% for $^{85}Sr$, and 15.1% for $^{131}I$, while being less than 6% for other radionuclides and elements. The AMP showed the highest adsorption yield for $^{137}Cs$. The adsorption yields of $MnO_2$ were more than 90% for all radionuclides and elements, except for $^{40}K$, $^{137}Cs$ and $^{203}Hg$ of which the adsorption yields were less than 8%.

• Geophysics and Geophysical Exploration
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• v.24 no.1
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• pp.20-27
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• 2021

Subsurface rock produces heat from the decay of radioactive isotopes in constituent minerals and gamma-ray emissions, of which the magnitude is dominated by the contents of the major radioactive isotopes (e.g., U, Th, and K). The heat production is generally calculated from the rock density and contents of major isotopes, which can be determined by mass spectrometry of drilled core samples or rock fragments. However, such methods are not easily applicable to deep boreholes because core samples recovered from depths of several hundred meters to a few kilometers are rarely available. A geophysical logging technique for boreholes is available where the U, Th, and K contents are measured from the gamma-ray spectrum. However, this technique requires the density to be measured separately, and the measurement depth of the equipment is still limited. As an alternative method, a normal gamma-ray logging tool was adopted to estimate the heat production from the total gamma activity, which is relatively easy to measure. This technical report introduces the development of the proposed method for evaluating the heat production of a granitic rock mass with domestic commercial borehole logging tools, as well as its application to a ~2 km deep borehole for verification.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.135-140
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• 2005

Voltage of radiometer is measured experimentally using the radiation apparatus in each case of iron- and copper-plates as specimen heating device. The length between radiometer and conical shield and the temperature of specimen heating device are considered as variables. The length between radiometer and conical shield controls the amount of radiation from the specimen heating device. Emissivity for both iron-and copper-plates are calculated by using Stefan-Boltzmann equation. One of results shows that emissivity for both materials increases as the length between radiometer and conical shield increases.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2104-2105
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• 2008

작업자들이 현장에서 착용하는 안전모는 안전모 본연의 기능 때문에 통풍의 제한을 받게 된다. 이로 인해 작업자들은 작업 시 많은 땀을 흘리게 되며 작업자들이 흘리는 땀은 머리받침 끈과 머리고정대등에 흡수되어 각종세균을 번식하게 되고 이로 인해 냄새가 나게 된다. 최근 들어 원적외선 방사율이 뛰어난 천연소재들이 개발되고 있으며 원적외선은 항균과 탈취능력이 탁월한 것으로 알려지고 있다. 본 논문에서는 상기 나열된 문제점을 해소하기 위하여 상온에서 원적외선 방사율이 높은 소재와 수분의 흡,배출 능력이 뛰어난 소재를 사용하여 안전모내부의 냄새와 세균번식을 줄이는 방안을 제시 하고자 한다.

• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.66-79
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• 2019

The aim of the study is to use the by-products sawdust, formed during sawing and mandarin peel which are agricultural by products. The boards were manufactured by mixing the sawdust and mandarin peel at different mixing ratio and density. In terms of changes in surface temperature of ceramics, we could found that the velocity was fast in the early time of heat transfer until 10 minutes and after that the velocity increased but not very fast. At the elapsed time of 30 minutes, the surface temperature of ceramics increased with the carbonization temperature and rate of mandarin peel addition did not influence the surface temperature. Far - infrared emissivity had no constant tendency in rate of mandarin peel addition, it decreased with increase of carbonization temperature.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.05a
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• pp.123-124
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• 2010

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2008.05a
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• pp.99-100
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• 2008

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2008.05a
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• pp.101-102
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• 2008

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.254-255
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• 2005