• Proceedings of the KSRS Conference
• /
• 1999.11a
• /
• pp.227-230
• /
• 1999

Surface solar radiation over the sea is estimated using Visible and Infrared Spin Scan Radiometer data onbord Geostationary Meteorological Satellite(GMS) 5 for January, 1997 to December 1997 in clear and cloudy conditions. The hourly insolation is estimated with a spatial resolution of 5$\times$ 5 km grid. The island pyranometer belonging to the Japan Meteorological Agency is used for validation of the estimated insolation. It is shown that the estimated hourly insolation has RMSE(root mean square) error of 104 W/$m^2$. The variability of the hourly solar radiation was investigated on 3 areas over seas around Korean Peninsula. The solar radiation of East Sea is similar to Yellow Sea. The maximum value of solar radiation is on June of year. The maximum value in south sea is on August because weather is poor by low pressure and front in June

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.1
• /
• pp.54-60
• /
• 2011

Procedures for estimation of insulation thickness for a horizontal pipe for condensation control or personnel protection has been investigated, parallel to the previous work of a vertical wall case. Parameters include pipe diameter, emissivity, thermal conductivity, and operating temperatures. The results indicated that the surface emissivity plays a very important role in the design of insulation, specially for the case of high temperature application with low Bi. The effect of surface radiation in such case could be up to 65% of the total. Required insulation thickness for the surface temperature control increases as pipe diameter increases and as surface emissivity decreases. Adequate revision of specifications or standards to include newly invented insulation materials with high emissivity has been also suggested.

• Journal of Korean Neurosurgical Society
• /
• v.54 no.6
• /
• pp.521-524
• /
• 2013

Ependymoma can spread via cerebrospinal fluid, but late spinal recurrences of intracranial tumor are very rare. We describe a case of a 33-year-old male who presented with multiple, delayed, recurrent lesions in the spinal cord from an intracranial ependymoma. The patient underwent gross total resection and postoperative radiation therapy 14 years prior to visit for a low grade ependymoma in the 4th ventricle. The large thoraco-lumbar intradural-extramedullary spinal cord tumor was surgically removed and the pathologic diagnosis was an anaplastic ependymoma. An adjuvant whole-spine radiation therapy for residual spine lesions was performed. After completion of radiation therapy, a MRI showed a near complete response and the disease was stable for three years.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.8
• /
• pp.56-64
• /
• 2012

This paper proposes a novel maximum power point tracking (MPPT) control algorithm considering radiation to improve efficiency of PV system. The proposed algorithm is composed perturb and observe (PO) method and constant voltage (CV) method. PO method is simple to realize and CV method is possible to tracking MPP with low radiation. Response characteristics of proposed algorithm are compared to conventional MPPT algorithm such as PO method, IC method and CV method with radiation variation. This paper proves the validity of proposed algorithm through the analysis results.

• The Journal of the Acoustical Society of Korea
• /
• v.18 no.1E
• /
• pp.20-26
• /
• 1999

Although the radiation impedance of a transducer with a regular square surface has been studied by many researchers, the formulas are still very complicated, which results in long computation time and low accuracy. In this paper, we propose a new algorithm for the calculation of acoustic radiation impedance in which the regular square vibrating surface of a transducer is divided into small elements and duplicate calculations are eliminated in the process of calculating mutual effects of the elements. Using this algorithm, shorter computation time and higher accuracy of results can be obtained. As a demonstration, the self and the mutual radiation impedance of transducers with a regular square surface are calculated and the accuracy of the results is evaluated.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1998.02a
• /
• pp.18-18
• /
• 1998

F First I will introduce our works how to improve the crystal growth t technique for Rare earth pnictides and chalcogenides. All these substances h have hi양1 vapor pressure and high melting print up to 3$\alpha$)()C. 까len we employ m the tungsten or molybden crucibles and enclose the sample by 빼e welding of m the lid with high current electron beam. We cannot elevate the temperature up t to 3$\alpha$)()C without suitable radiation shield because rate of radiation loss r rapidly increase in such a high temperature regions. There were no good r radiation shield but we discovered that the p-BN could work as an excellent r radiation shield after checking of the many substances. S Secondly I will show several interesting and unusual 뻐ysical properties of obtained crystals under high magnetic field, hi양1 pressure and also i including angle resolve photoemission spectroscopy. I will stress the p properties of the low carrier concentration with strong correlation on C댐, U USb and Yb4As3

• Journal of the Korea Furniture Society
• /
• v.11 no.1
• /
• pp.25-29
• /
• 2000

This study was carried out to analyze the ultrasonic properties of sound board which was glued with various adhesives and to evaluate which adhesive is the best for the acoustic radiation of the musical instrument. The results are as follows: 1. Animal glue is the best adhesive for the sound board with respect to the acoustic radiation ratio of the musical instruments. Epoxy resin and polyvinyl acetate resin are the next group, urea formaldehyde resin and Hot melt are the third group, polychloroprene(CR) resin is the lowest. 2. Epoxy resin, animal glue and Titebond(PVA) give the highest shear strength and the highest wood failure relatively Hot melt and polychloroprene(CR) resin do not meet the standard because of low wood failure.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05d
• /
• pp.28-33
• /
• 1996

Wind-speed has much effect on the dispersion of the radioactive effluents released into the atmosphere. Accurate measurement of low wind-speeds is very important for the realistic assessment of radiation exposure. The objective of this study is to analyze the effects of different calm conditions on the radiation exposure due to the normal operation of a nuclear facility at KAERI (Korea Atomic Energy Research Institute) site. When calm condition is changed from 0.5 m/sec to 0.21 m/sec, the effects on radiation exposure show a distinct difference.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.2
• /
• pp.116-120
• /
• 2004

In order to investigate low molecular antioxidants synthesized by enhanced UV-B radiation, we used the seedlings of two rice varieties. Woonjangbyeo, UV-tolerant, and Hwajoongbyeo, UV-susceptible, were subjected under supplemental UV-B irradiation. When rice seedlings were irradiated with UV light for short period, biosynthesis of total phenolic compound, ascorbate and glutathione were momently reduced. With an increase of UV-B radiation, however, those were slightly synthesized. The content of lipid peroxides in UV-challenged rice leaves was considerably increased after 12 hrs of UV-B treatment. Lipoxygenase activity under supplemental UV-B radiation was differently responded on rice varieties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.473-476
• /
• 2004

This study has investigated radiation degradation of low density polyethylene(LDPE). Samples were irradiated using a $Co^{60}\;\gamma-ray$ and ray up to 800 kGy at a dose rate of 5 kGy/hr in the presence of air atmosphere at room temperature. After irradiation, free radical measurement of LDPE has established by electron spin resonance(ESR). Then, each sample was stored for 2 weeks. ESR measurement showed that free radical concentration(FRC) was increased with radiation dose and changed from alkyl, allyl radical to peroxy radical with time.