• The Transactions of the Korean Institute of Electrical Engineers A
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• 제48권5호
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• pp.636-642
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• 1999

The synthesis of the 3D images is the most important part of the virtual reality. The ray tracing is the best method for reality in the 3D graphics. But the ray tracing requires long computation time for the synthesis of the 3D images. So, we implement the ray tracing with software and hardware. Specially we design the hit-test unit with FPGA tool for the ray tracing. Hit-test unit is a very important part of ray tracing to improve the speed. In this paper, we proposed a new hit-test algorithm and apply the parallel architecture for hit-test unit to improve the speed. We optimized the arithmetic unit because the critical path of hit-test unit is in the multiplication part. We used the booth algorithm and the baugh-wooley algorithm to reduce the partial product and adapted the CSA and CLA to improve the efficiency of the partial product addition. Our new Ray tracing processor can produce the image about 512ms/F and can be adapted to real-time application with only 10 parallel processors.

• Proceedings of the KIEE Conference
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.402-404
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• 1997

The synthesis of the 3D images is the most important part of the virtual reality. The ray tracing is the best method for reality in the 3D graphics. But the ray tracing requires long computation time for the synthesis of the 3D images. So, we implements the ray tracing with software and hardware. Specially we designs the hit-test unit with FPGA tool for the ray-tracing.

• Korean Journal of Materials Research
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• 제5권1호
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• pp.12-21
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• 1995

The study was performed to study the effects of strain rate on acoustics emission( AE) during bulging test in corrosive environmentsynthetic sea water. The strain rates used were in the range $4 \times 10^{-6}S^{-1}$ to $1 \times 10^{-4} \times S^{-1}$ and the parameters used to evaluate AE signal characteristics were AE hit and amplitude. It can be observed that the cumulative AE hit and average amplitude during fracture process increase highly at decreasing strain rates while the equivalent fracture strain and the crack length of circumferencial direction become decrease. The peak point of AE signal characteristic parameters approach to the first half of test. When the average amplitude per unit equivalent fracture strain was above 20dB, it was definitly observed stress corrosion cracking phenomena. Additional, we knew that the AE test had the possibility to evaluate SCC susceptibility with various strain rates.

• Korean Journal of Adult Nursing
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• 제15권2호
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• pp.267-277
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• 2003

Purpose: The purpose of this study was to evaluate the applicability of braden scale to assess pressure ulcer risk patients and to identify additional risk factors of pressure sores in an neurologic intensive care unit. Method: The subjects of this study were 66 patients in neurologic intensive care units. Data was prospectively collected from Sep. to Dec., 2002. Data were analyzed by mean, percentage, t-test, chi-square, discriminant analysis using Spss pc+. Result: The results of this study were as follows: 1) There was a significant difference between scoring of braden scale and pressure ulcer development. The subscales that predicted pressure ulcer development using braden scale only were sensory perception, moisture, mobility, friction & shear. By using these subscales, sensitivity was 86.7%, and specificity was 61.1%, and total hit ratio was 72.7%. 2) Additional pressure ulcer risk factors which showed significance for discriminating two group were protein, albumin, gender, level of consciousness, pattern of bowel elimination. By using the combination of these additional risk factors in addition to the braden scale, total hit ratio increased to 84.8%. Conclusion: This data suggest that albumin, protein, gender, level of consciousness, pattern of bowel elimination in addition to the braden scale should be included in the pressure sore assessment tool.

• Korean Journal of Oriental Medicine
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• 제3권1호
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• pp.67-83
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• 1997

In order to search for anti-influenza virus type A agents from Korean medicinal herbs, we selected 100 medicinal herbs, based on a review of the Korean traditional medicine books. Four of 100 Korean medicinal herbs, MM-40, MM-55, MM-63, MM-110, exhibited very strong anti-influenza virus activity. The fractions of four medicinal herbs, which had very strong anti-influenza virus activity, were tested for antiviral activity by means of Haemagglutination inhibition test(HTT), 40% MeOH fraction of MM-40, $H_2O$ fraction of MM-55, 20% fraction of MM-63 3nd $H_2O$ fraction of MM-110 had strong anti-influenza virus activity at the range of $78{\mu}g/ml$ to $156{\mu}g/ml$, 1.56mg/ml to 100mg/ml, 6.25mg/ml to 50mg/ml and $48.7{\mu}g/ml$ to $780{\mu}g/ml$, respectively. These results of HIT indicated that fractions of Korean medicinal herbs might inhibit either attachment of virus to cell surface receptor or penetration of virus into cell during the initial stage of infection. In the cytotoxicity of fractions against red blood cells, 40% MeOH fraction of MM-40, 20% fraction of MM-63 and $H_2O$ fraction of MM-110 showed cytotoxicity at the range of $78{\mu}g/ml$ to 10mg/ml, 50mg/ml to 100mg/ml and $195{\mu}g/ml$ to 100mg/ml, respectively, whereas $H_2O$ fraction of MM-55 did not show cytotoxicity. In order to establish influenza virus adapted animal model, influenza virus type A were passaged 3 and 4 times successively in Balb/c mouse. As a result, we had 4 HA unit titers on the 5 days of 3rd passages and 7 days of 4th passages after infection, respectively.