• The Bulletin of The Korean Astronomical Society
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• v.14
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• pp.12.1-12.1
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• 1989

• The Bulletin of The Korean Astronomical Society
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• v.33 no.2
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• pp.77.1-77.1
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• 2008

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.1
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• pp.1-9
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• 1992

Radiation heat transfer was calculated for initial stage of crystal growth in Czochralski crystal growth system. View factors among surface elements were calculated for the estimation of heat evolution and all the surfaces were assumed to be diffuse-gray. The values of view factors were greatly different along the position of surface elements. The dissipated amounts of heat flux from the melt surface were 3.6 times larger than those from the crystal surface at the initial stage of crystal growth and this amounts were greater when the surface elements were not considered. The trijunction part of the crystal was greatly affected by the melt surface near the crystal. Consequently radiation heat transfer between surface elements must be considered in order to correctly simulate the initial crystal growth.

• Solar Energy
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• v.11 no.1
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• pp.3-15
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• 1991

In this study global radiation and global illumination are directly measured and diffuse radiation and diffuse illumination measured utilizing semi-circular shadow ring. By analyzing measured radiation data, clear and overcast sky are classified according to the sky classification method used in Mantes, France. Measured illumination data are analyzed and 1) Clear sky illumination on a horizontal surface as a function of solar altitude. 2) Overcast sky illumination on a horizontal surface as a function of solar altitude, 3) Monthly variation of illumination. 4) Cumulative percentage of illumination, 5) Daylight intensity as a function of hours in a typical day, 6) Average number hours per day of illumination above 10 and 20klx are presented as a climatic data for daylighting design for Seoul, Korea.

• The Korean Journal of Nuclear Medicine
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• v.6 no.2
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• pp.7-20
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• 1972

Experimental radiation nephritis was produced in 15 rabbits by X-irradiation. About $2,000{\gamma}$ (tissue doses) were given to both kidneys of a rabbit in 5 days. Other tissues and organs except both kidneys were protected with 2mm thickened lead plates. 5 weeks after the last irradiation, blood pictures, blood pressures, B.U.N., serum creatinine, Ca, Mg, Fe levels and serum erythropoietin activity of the irradiated rabbits were studied. After finishing above studies, rabbits were sacrificed and both kidneys were removed and examined histopathologically. Same laboratory and pathological studies were performed in 6 control rabbits. In this study, the author obtained following results. 1) Both kidneys of rabbitis with experimental raditation nephritis showed marked histopathological changes, i.e.: renal tubules showed diffuse cloudy swelling, impacted intraluminal hyaline casts and focal precipitations of lime salts on the tubular epithelium. Diffuse interstitial fatty necrosis and various degrees of fibrotic infiltrations on the interstitium were also seen in association with focal lymphocytic infiltrations. Hyaline degenerations were observed on the glomeruli and small vessels. 2) Experimental radiation nephritis rabbits showed marked lowering in R.B.C. counts, decreased hemoglobin levels, low hematocrit values and leucopenia in comparison with those of control rabbits. (P<0.01). (Table 1 & 2). 3) Mild proteinuria were observed in experimental radiation nephritis in rabbits. 4) The levels of B.U.N. and serum creatinine increased in experimental radiation nephritis. (P<0.01). (Table 1,3 & 4) 5) The levels of serum Ca and Mg Showed no statistical difference in comparison with those of control rabbits. (P>0.05) (Table 3 & 4). 6) No statistical correlations were observable between the levels of B.U.N. and Hb. values. (${\gamma}=-0.223$) No close correlations (${\gamma}=-0.328$) were noticed between the levels of B.U.N. and serum iron levels. 7) Erythropoietin activity (R.B.C. $^{59}Fe$ Incorporation) was measured by the modified Fried method. No change in its activity was noticed in radiation nephritis group comparing with that of the control group. (P>0.05). (Table 1,3 & 5). 8) Carotid artery blood pressures showed also no difference. (P>0.05). (Table 1 & 2).

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.63.2-63.2
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• 2010

Solar radiation data are used in several forms and for a variety of purposes. The most detailed information we have is beam and diffuse solar radiation on a horizontal surface, by hours, which is useful in simulations of solar processes. Daily data are more often available and monthly total solar radiation on horizontal surface can be used in some process design methods. However, as performance is generally not linear with solar radiation, the use of average may lead to serious errors if non-linearities ara not taken into account. It is also possible to reduce radiation data to more manageable forms by statistical methods. The control of the quality of most measurements is relegated to the control of the measuring instruments and measuring processes themselves. An accurate measurement will usually result from the use of a high-quality instrument that has been accurately calibrated and is properly used by a qualified individual.

• Journal of The Korean Astronomical Society
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• v.48 no.1
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• pp.67-73
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• 2015

We present a novel method to implement time-delayed propagation of radiation fields in cosmological radiative transfer simulations. Time-delayed propagation of radiation fields requires construction of retarded-time fields by tracking the location and lifetime of radiation sources along the corresponding light-cones. Cosmological radiative transfer simulations have, until now, ignored this "light-cone effect" or implemented ray-tracing methods that are computationally demanding. We show that radiative transfer calculation of the time-delayed fields can be easily achieved in numerical simulations when periodic boundary conditions are used, by calculating the time-discretized retarded-time Green's function using the Fast Fourier Transform (FFT) method and convolving it with the source distribution. We also present a direct application of this method to the long-range radiation field of Lyman-Werner band photons, which is important in the high-redshift astrophysics with first stars.

• Radiation Oncology Journal
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• v.4 no.1
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• pp.51-53
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• 1986

Malignant lymphoma of the sinus is very rare but potentially radiocurable neoplasm. The disease is tend to be localized to the sinus and spread to adjacent local structures on initial presentation, and change to generalized lymphoma is uncommon. Most of sinus lymphoma is diffuse histiocytic type. Radiotherapy to the primary and neck nodes is the treatment of choice, and a survival rate of $50-70\%$ can be expected.

• Journal of the Korean Institute of Navigation
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• v.4 no.2
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• pp.1-6
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• 1980

Computer simulation results on the radiation pattern of an ultrasonic beam by the plurall arrangement of the transducers were reported by Sin (1979). This paper describes on the measurement of radiation pattern in case of one vibrox transducer and two vibrox transducers by varying the interval between the transducers. The measured results obtained are as follows; 1. Radiation wave of ultrasonic transducer is propagated to diffuse with spherical wave from center of transducer. 2. In case of one vibrox transducer, the greater the length of transducer, the sharper becomes the radiation pattern. 3. In case of two vibrox transducers, the maine lobe is revealed at the center of two transducers, it is shown difficult to make control freely of radiation pattern by varying merely the interval of transducers.

• Journal of Bio-Environment Control
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• v.7 no.4
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• pp.324-329
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• 1998

Effect of roof slope on the transmissivities of direct and diffuse solar radiation using a computer simulation model developed by Kim and Lee(1997) was analyzed for 10-span glasshouse located in Seoul(37$^{\circ}$34' N), Chonju(35$^{\circ}$49' N) and Cheju(33$^{\circ}$31' N). Transmissivities of diffuse solar radiation in glasshouse with roof slopes of 15, 20, 24.6, 30 and 35 degree were calculated as 61.3, 61.6, 61.7, 56.8 and 58.6%, respectively. Transmissivities of direct solar radiation(TDSR) during the period except summer season were highly affected by the roof slope. During the winter season, TDSR in glasshouse with roof slopes of 30 and 35 degree were higher than those with other roof slopes. Also, during the period except winter season, TDSR in glasshouse with roof slope of 20 degree were higher than those with other roof slopes. Difference in TDSR with latitude was significant during the period from October to February. At this period TDSR were highly appeared at lower latitude. Effect of roof slope on TDSR in S-N greenhouse was smaller than those in E-W greenhouse. It is considered that direct solar radiation highly transmitted in the glasshouse with roof slope of 20 degree.