• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.219-227
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• 2012

Daily solar radiation is essential for water resources planning and environmental impact assessment. However, radiation data is not commonly available in Korea other than in big cities, and there has been no direct measurement for rural areas where water resources planning and environmental impact assessment is usually most needed. In general, missing radiation data is estimated from nearby regional stations within a certain distance, and this study compared two dominant methods (modified Angstrom equation and transmittance interpolation method) at six stations in Nakdong River watershed area. Two methods shows a similar level of accuracy but the transmittance interpolation method is likely to be superior in that there is no need for any measurement element since the modified Angstrom equation require the sunshine hour measurement. This study will contribute to improve water resource and water quality management in Nakdong River watershed.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.56-60
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• 2002

Since the transmittance of solar radiation directly affected by the structural frames of greenhouse can be changed according to the ratio of diffuse to direct radiations, it is necessary to investigate the transmittance of greenhouse at the different weather conditions. We can easily get the data of total solar radiation from the Meteorological Administration, but we have to personally measure the photosynthetic photon flux (PPF). If the relationship between total solar radiation and PPF is established, the PPF can be simply acquired from the relationship. Sol it is required to develop the equation to calculate PPF depending on weather condition. This study was conducted to determine the transmittance of PPF at canopy level in glasshouse and the correlation between total solar radiation and PPF at clear and cloudy days. The variation phase of greenhouse transmittance at clear day was very different from that at cloudy day. It was concluded that the proper transmittance, depending on the weather condition, should be adopted to calculate the accurate total solar radiation and PPF in greenhouse. The transmittance of solar radiation was the same as that of PPF in greenhouse. It was confirmed that the ratio of PPF to total radiation increased as the amount of cloud increased. The correlation between the hourly total solar radiation and PPF was derived.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.4
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• pp.375-382
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• 1987

Accurate solar radiation data are fundamental to the design of HVAC systems and solar driven devices. Unfortunately, the total radiation data on a horizontal surface has been only reported by meteorological office. Consequently, there is interest in development of model to estimate the solar radiation data. Based on the statistically estimated TAC data which were obtained from measured hourly values collected over a period of ten years at Seoul, the solar radiation model was determined. Atmospheric transmittance for this model was presented in the form of polynominal.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.4
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• pp.316-322
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• 1992

A simplified TAC method was developed for the selection of solar atmospheric transmittance data fundamental to the calculation of design solar radiation for the peak cooling load calculation using ETD method. The summer and autumn solar atmospheric transmittance data of the 11 major cities in Korea were obtained. Based on the simplified TAC method, the atmospheric transmittance data were selected by the TAC 2.5% of July instead of the TAC 2.5% of June through September for summer and the TAC 5.0% of October instead of the TAC 2.5% of October and November for autumn. Results show that the atmospheric transmittance data at solar noon were in the range of 0.61-0.66 for summer and 0.78-0.82 for autumn except for Pusan and Incheon.

• Journal of the Optical Society of Korea
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• v.16 no.3
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• pp.191-195
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• 2012

Among the atmospheric effect of laser propagation, the variations of the radiation transmittance by water aerosol evaporation have quantitatively been investigated. When the aerosol was exposed by a 1.07 ${\mu}m$ cw fiber laser, the increased amount of the transmittance variation was a maximum of 19.1% and the volume concentration variation of aerosol was observed as an increasing of laser intensity. Also, significant irregularity of refractive index was not found in the heated area during the continuous laser heating.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.4
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• pp.205-209
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• 2010

Transparent and conductive AZO films were deposited on the glass by using radio frequency (RF) magnetron sputtering with intense electron radiation, simultaneously. After deposition, the effect of electron radiation energy on the optical and electrical properties of AZO was investigated. In XRD measurements, the films irradiated with intense electron beam show the larger grain size than that of the films prepared without electron radiation. Sheet resistance was also dependent on the electron radiation energy, while the optical transmittance in visible wavelength region was not affected seriously by electron radiation. X-.ray diffraction, UV-Vis spectrophotometer and four point probes were used to observe the crystallization, optical transmittance and sheet resistance, respectively.

• Laser Solutions
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• v.2 no.2
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• pp.18-26
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• 1999

An innovative real-time weld monitoring technique using chromatic filtering of the thermal radiation from a weld pool is developed. The thermal radiation from the weld pool is focused on an aperture and the transmitted thermal radiation is monitored at two wavelengths with high-speed single-element detectors. Due to the chromatic aberration introduced in the focusing optics, the transmittance curve of thermal radiation varies by the wavelength. Owing to this difference in the transmittance, the local variation of thermal radiation from the weld pool can be monitored by processing the two spectroscopic signals from two detectors. In this paper, the algorithms to monitor the laser power on the weld specimen and the focus shift we investigated and the performances of laser power and focus monitoring are shown for a pulsed Nd:YAG laser welding. The monitoring of the weld pool size variation is also discussed.

• The Korean Journal of Community Living Science
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• v.14 no.3
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• pp.13-19
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• 2003

The purpose of this study was to investigate the UVA radiation protection effects of summer hats currently on the market with the purpose of making it possible to choose a hat with suitable UVA protection. Twelve different summer hats from the market were selected for the experiment. The results are summarized as follows: It is more effective to wear a hat than not wear a hat to block UVA radiation. Summer hats with the greatest degree of protection, from highest to lowest, are cotton, straw2, and straw1. In the area of the forehead, which is rarely influenced by the irradiation angle, the cotton hat was the most effective in protecting from UVA radiation because the material density was greater than that of the straw hats. A hat with a 8.5 cm brim was more effective at blocking UVA radiation on the jaw than 6 cm, 4 cm, and 0 cm wide brims, but it still couldn't block the radiation completely. Irradiation amounts at 11:00 AM on the forehead, jaw! s and left and right cheeks were lower than amounts measured on the back of the neck. This revealed that irradiation amounts depend on the shape of the hat and time of day. A hat with a brim encircling the head was found to be more effective in blocking UVA radiation than a hat with only a front or side brim.

• Journal of the Korean Ceramic Society
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• v.32 no.6
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• pp.697-702
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• 1995

The rough growth surfaces of diamond films fabricated by the hot filament CVD were polished using thermomechanical polishing method. And then, its application to the optical windows was discussed through the measurement of transmittance in the range of infrared radiation and analysis of surfaces structure. The results were compaerd with those of the films polished with conventional mechanicla polishing. The transmittance of the mechanically polished film reached 57~66% over the whole range from 500 to 4000 cm-1. But the transmittance of the film polished with thermomechanical polishing method was reduced below 35%. This decrease in transmittance was due to both the graphitization of diamond on the polished surface and the growth of $\beta$-SiC at diamond/Si interface during polishing. The residual Fe in hte thermomechanically polished surface was confirmed by SIMS analysis. This Fe played the role of the graphitization of near surface region of the diamond film.

• Journal of the Korean Solar Energy Society
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• v.31 no.1
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• pp.59-67
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• 2011

This paper is focused on the effect of indoor temperature rise according to the use of windows and blinds in double skin facade in summer. For the experiment, we set up the mock-up of double skin facede and measuring temperature and solar radiation. Total 7 cases were used for measuring solar transmittance and indoor temperature rise. When the venetian blind was not installed, solar transmittance was 44.5%, and solar transmittance for the case that installed the venetian blind (angle 0) was 22.5%. Cases that opened inner and outdoor windows for ventilation showed lower indoor temperature rise than cases with closed windows. In addition, Case 5 (opened inner and outdoor windows with the venetian blind (angle 0) to reduce solar transmittance) indicated lower indoor temperature rise than Case 3(opened inner and outdoor windows). Consequently, Case 5 which uses inner and outdoor window for ventilation and venetian blind to reduce solar transmittance is the most effective way to reduce indoor temperature rise among all cases tested in this research.