• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.235.1-235
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• 2001

• Progress in Medical Physics
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• v.13 no.4
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• pp.218-223
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• 2002

Stereotactic radiosurgery for intracranial lesion is well established since the Lars Leksell first introduced radiosurgery concept in 1951 Its use in the treatment of spinal lesion has been limited by the availability of effective immobilization devices. The first clinical experience of the spinal stereotactic radiosurgery technique was reported by Hamilton AJ. in 1995. Recently, Optic-guided patient positioning technique for extracranial stereotactic radiosurgery was developed and reported. This study is for assess the target positioning accuracy of the optic guided patient positioning system Exactrac (BrainLab., Inc, Germany). We have designed phantom for assess the accuracy of spinal stereotactic radiosurgery The infrared reflective body markers attached to the relatively immobile part of the body and a series of 2 mm CT images was taken. The image sets were transferred to the planning computer. During the radiosurgery treatment, we measure the real-time display showing the positioning values from Exactrac computer. And we compare the isocenter deviation from irradiated center point of the film which was mounted on the lesion site of the phantom and pin hole site of that film. The accuracy of the ExacTrac system in positioning a target point shows enough for the clinical applications.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.197-198
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• 2003

최근 미국 및 유럽의 선진국에서는 시민에게 맑은 하늘을 체감적으로 느낄 수 있는 Clear Sky(푸른하늘)를 실현하기 위하여 시정(visibility)분야에 대한 연구가 급진적으로 확산되어 가고 있다. 미국의 IMPROVE, 북미대륙(미국, 캐나다. 멕시코) 공동연구인 NARSTO, 유럽대륙의 EURO-TRAC II 등, 선진국의 연구기관들은 인체에 유해할 뿐만 아니라 시정장애에 영향이 지배적인 미세입자(Dp 〈 2.5$\mu\textrm{m}$)에 대한 화학적이며, 광학적인 특성을 실시간으로 관측 및 분석하도록 권고하고 있다. 현재까지의 우리나라의 시정변화에 대한 분석은 광학적인 관측에 있어서는 실시간으로 시행되어 왔으나, 에어로졸의 화학적인 분석에 있어서는 일일 관측이 일반적인 관측간격이었다. (중략)

• The Korean Journal of Soil Zoology
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• v.8 no.1_2
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• pp.32-36
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• 2003

Diversity and altitudinal distribution of the ground-beetles including Silphidae were investigated on Mt. Gabjangsan, Sangju city, Korea. Of the collected 10 species belonging to 3 families, Synuchus cycloderus was the most abundant species and S. nitidus was the relatively more abundant than the other species. The highest number collected was at alto 700 m. Simpson dominance index was 0.66 the highest at 700 malt., whereas, 0.47 at alto 800 m, was the lowest. The highest Simpson diversity index was noticed at alto 800 m (0.53). Also, seasonal indices of diversity and dominance of Simpson and Menhinick index were provided.

• Nuclear Engineering and Technology
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• v.34 no.5
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• pp.421-432
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• 2002

As one of the advanced design features of the APR1400, direct vessel injection (DVI) system is being considered instead of conventional cold leg injection (CLI) system. It is known that the DVI system greatly enhances the reliability of the emergency core cooling (ECC) system. However, there is still a dispute on its performance in terms of water delivery to the reactor core during the reflood phase of a large-break loss-of-coolant accident (LOCA). Thus, experimental validation is under progress. In this paper, test results of direct ECC bypass performed in the steam-water test facility tailed MIDAS (Multi-dimensional Investigation in Downcomer Annulus Simulation) are presented. The test condition is determined, based on the preliminary analysis of TRAC code, by applying the ‘modified linear scaling method’with the l/4.93 length scale . From the tests, ECC direct bypass fraction, steam condensation rate and information on the flow distribution in the upper annulus downcomer region are obtained.