• 자원환경지질
• /
• 제28권3호
• /
• pp.279-286
• /
• 1995

The amount of the high level radioactive wastes in Korea will be increased up to 14,297 MTU about 2010 year. Most of countries adopt the concept of deep burial repository in high level radioactive waste disposal. Because the high level radioactive wastes are very toxic in biosphere and to human, the data verifing its never return to the biosphere are requisite for the disposal. Presently, the evaluating techniques for the high level radioactive waste disposal are not fully developed. Therefore, in order to dispose the high level radioactive wastes in proper time the R & D of it is urged in our country. The R & D and/or the international joint research programme for the disposal of high level wastes have already been proceeded. In our country no plan for its disposal has been prepared. It is the time that the direction of the R & D is to be discused seriously. The R & D for the disposal of high level radioactive wastes in Korea is believed to be focused on developing the pecular techniques such as in situ characteristics of groundwater flowage, and change of properties of in situ rock mass at thermal effects.

• 한국의류학회지
• /
• 제47권6호
• /
• pp.1193-1203
• /
• 2023

This study aims to provide primary data regarding the thermal stress of disposable personal protective coveralls. Thermal stress and surface temperature measurements were taken among ten men wearing coveralls. The size of the ten men corresponds to a size eight in Size Korea. As a result of thermal stress, sensations of humidity and discomfort were higher when wearing Level C compared to Level D. Level D felt significant thermal stress in their upper body after exercise. However, they did not feel such stress in their lower body. Level C felt thermal stress in their upper and lower body after exercise. In addition, in Level C, the ratings of perceived exertion blood pressure and pulse rate after exercise were higher than those of Level D. Furthermore, the surface temperature of disposable personal protective coveralls among Level C was slightly higher than that of Level D.

• 한국항공운항학회지
• /
• 제14권2호
• /
• pp.9-16
• /
• 2006

FAA AC120-40B Level D flight dynamics model for T-50 Full Mission Trainer was successfully developed. Since AC120-40B Level D requires the quantitative validation tests for simulation model compared with flight test data, T-50 flight test data for each validation test item was gathered, and also automatic test environments which include AFT (Automatic Fidelity Tester) and STA (Simulation Test Analyzer) were developed. The final test results after the iterative test-tuning processes were all within the tolerances specified in AC120-40B Level D. Qualification Test Guide, QTG contains the detail test processes and results.

• Journal of Information Display
• /
• 제13권4호
• /
• pp.159-166
• /
• 2012

In this paper, a display's emotional image quality can be primarily determined by designing the proper luminance level. Though displays with high luminance are preferred, too much light emission from a display may cause glare or visual fatigue to viewers. To find out the proper luminance level based on various video contents, this study was conducted with an OLED display with a real-black level and a wide color gamut, and with an LCD display with a high luminance level, to set the glare threshold under various conditions. The optimum luminance levels according to the display's loading ratio were found, and the maximum luminance that did not cause a glare in the test is proposed.

• Journal of Nutrition and Health
• /
• 제31권1호
• /
• pp.46-61
• /
• 1998

This study was carried out to evaluate the effects of vitamin D nutritional status on bone mineral density of adults (21-49 years). To attain the aim, we measured bone mineral density (BMD) of the subjects at distal radius by single-photon absorptiometry (SPA). Serum level of 25-hydroxyvitamin D(25-(OH)D) , known to be the best indicator of indicator of vitamin D status in humans was analyzed . The factors affecting this vitamin D level were also investigated in autumn in 122 young adults. Serum level of 25-(OH)D was measured by high pressure liquid chromatography(HPLC) and biochemical variables, general health status, time spent outdoors, and dietary intakes of the subjects. BMD of the male subjects was significantly greater than that of female subjects. Weight, activity and total energy expediture (TEE) showed a positive correlation with distal BMD. The mean level of serum 25-(OH)D was 24.4$\pm$11.0 ng./ml and by sex, 26.0$\pm$6.8ng/ml for males and 23.3$\pm$12.3ng/ml for females , the level was significantly higher in male (p<0.01). there was significant correlation between BMD at distal-radius and s-25(OH)D levels (p<0.001). The serum level fo parathyroid hormone (PTH) showed a negative correlation with BMD(p<0.05), with the more obvious correlation in females. Vitamin D intake was estimated to be 3.75$\pm$2.19ug/day in average. Among the nutrients studied, protein ,fat, calcium , and vitamin D intake were positively correlated with distal BMD. When food frequencies were concerned , milk and dairy products showed a significant positive correlation with the BMD level, and driedfoods, eggs , fats and oils, and cereals also showed a positive correlation. Time spent outdoors was estimated to be about 70 minutes in average and positively correlated with the distal BMD level(p<0.01). During the day, the specific time between 12 :00pm and 2:00pm showed the most significant correlation with BMD (p<0.001). Multiple regression analysis with the variables showed that distal BMD could be fit 31.9% by the time spent outdoors a day, intake of Ca and vitamin D, and TEE. The standardized estimates were 0.344 for vitamin D intake, 0.284 for Ca intake 0.179 for the time spent outdoors a day and 0.273 for TEE. For males, s-25*OH)D level, TEE and time spent outdoors during a day showed a significant correlation. For females, intake of Ca and vitamin D could fit about 27.1% of the distal BMD.

• 대한임상검사과학회지
• /
• 제39권1호
• /
• pp.37-41
• /
• 2007

This study was carried out to investigate the cadmium level in blood by age, gender, and smoking status among 162 elderly subjects in Gyeongnam Province from September 2006 to February 2007. The cadmium level in blood was analyzed by atomic absorption spectrophotometer. Subjects were classified according to smoking status and divided into smokers and non-smokers, smoking duration, daily smoking habits, age, and gender. Mean blood cadmium levels in male and female were $0.70{\pm}0.41{\mu}g/dL$ and $0.57{\pm}0.32{\mu}g/dL$ respectively, with no significant differences between the two groups. Cadmium levels in the blood of smokers and non-smokers were $0.57{\pm}0.32{\mu}g/dL$, $0.90{\pm}0.44{\mu}g/dL$ respectively, with the cadmium level of smokers being significantly higher than that of non-smokers. In comparison by age, cadmium levels in the blood of subjects over the age 70 years and over the age 80 years were $0.91{\pm}0.44{\mu}g/dL$, $1.02{\pm}0.39{\mu}g/dL$ respectively, showing a significantly higher blood cadmium level than that of non-smokers. when compared by the amount of daily cigarette consumption, there were no significant differences in the blood cadmium level between groups. However when compared by smoking duration, the blood cadmium level for the group of smoking duration of over 10 years was $1.15{\pm}0.38{\mu}g/dL$, significantly higher than $0.67{\pm}0.31{\mu}g/dL$ for the group of smoking duration of less than 10 years. In conclusion, longer smoking duration and older aged group showed higher cadmium level in blood. For more reliable results, further study of the elements that elevate the cadmium level in blood with more subjects and study variables will be needed.

• 기술혁신연구
• /
• 제11권2호
• /
• pp.123-149
• /
• 2003

The paper examines the effects of tax incentives on corporate R&D expenditures. We regress tax incentives and financial variables on the increase or the level of corporate R&D expenditures. Tax incentive variables are the magnitude of R&D tax credit and the level of reserve for R&D, while financial variables are the amount or increase of R&D expenditures in prior years, profitability, cash flows and Tobin Q. Sample firms are selected among the listed companies which reported R&D expenditures in the financial statements from 1995 to 2000. The results indicate that increase and level of R&D expenditures is positively influenced by the magnitude of R&D tax credit and the level of reserve for R&D. The amount of R&D expenditures has positive relationship with prior one-year R&D expenditures, while the increase of R&D expenditures has negative relationship with prior year increase and recent three year's average of R&D expenditures. The evidence is consistent to the hypothesis and results of other studies, which suggest that tax incentives for R&D encourage the corporate R&D expenditures.

• Animal Bioscience
• /
• 제36권3호
• /
• pp.471-483
• /
• 2023

Objective: This study was conducted to evaluate the interactive effects of dietary digestible tryptophan (dTry) and soy oligosaccharides (SO) on growth performance, caecal skatole level, and microflora of broiler chickens aged from 14 to 42 days. Methods: Three hundred and sixty broiler chicks were allocated equally to 36 cages at 14-day-of-age according to body weight and gender. Using a 3×2 factorial arrangement, 3 dietary dTry levels (0.18%, 0.23%, and 0.28%) supplemented with 0 or 3.5 g/kg of SO were used to create 6 diets (treatments). Each diet was fed to six replicates of 10 birds (60 birds/treatment), growth performance was measured. Caecal content samples were collected at 42 days of age. Results: Results showed that significantly different dTry level×SO interactions were found for average daily gain (ADG), caecal levels of indole, propionic acid, and butyric acid, and microbial Shannon index (p<0.05). Birds fed diet containing 0.23% dTry level with SO supplementation had higher ADG and lower feed/gain ratio than those fed the other diets (p<0.05). Broilers fed diets containing 0.28% dTry increased their caecal levels of indole and skatole compared with those containing 0.18% or 0.23% dTry (p<0.01), regardless of SO addition. SO supplementation to diets decreased the caecal skatole level by 16.17% (p<0.05), and increased the relative frequency of Clostridium IV (p<0.05), regardless of dietary dTry level. Conclusion: These results indicated that diets containing 0.23% dTry with SO supplementation positively promoted ADG, and decreased caecal skatole levels of broiler chickens. The dietary dTry level, SO affected the caecal skatole level, however, there was no interaction between them.

• 수산해양기술연구
• /
• 제23권4호
• /
• pp.163-168
• /
• 1987

1984, 85, 87년에 걸쳐 7~8월에 부산402호(380GT, 850PS)를 이용하여 한국동해안 주요항구 입구와 외해에서 해중소음과 선박기관소음의 해중음압 분포와 그 음의 스펙트럼 특성을 해황별로 환경소음과 선박기관진동소음으로서 비교.검토한 결과를 요약하면 다음과 같다. 1. 풍속 0~2m/sec일 때 깊이 5m층에서의 환경소음의 음압준위는 부산 동항에서는 108dB, 부산 남항에서는 106dB, 구룡포항에서는 101dB로서 항내에 소음원이 많을 때는 높고, 그렇지 않을 때는 낮았다. 한반도와 울릉도 중간의 외해에서는 다같이 100dB로서 항구 부근보다 낮았다. 또 외해에 있어서 깊이에 따른 음압의 분포는 깊이 20m, 70m 층에서는 5m층에서 보다 1~2dB 낮고, 100m층 이하에서는 100dB로 거의 일정했다. 2. 풍속 10~15m/sec일 때, 외해에서의 환경소음의 음압준위는 5m층에서 108dB이고 그 후 점차 낮아져 70m 층에서 100dB이며, 그 이하에서는 100dB로 모두 같았다. 선박기관진동소음의 음압준위는 깊이 5, 50, 100, 150, 200m층에서 각각 146, 125, 112, 110, 104dB로서 깊어짐에 따라 점차 낮아졌다. 3. 풍속 10~15m/sec일 때 외해의 깊이 5m층에서 10Hz, 100Hz, 1KHz, 10KHz의 주파수대에 있어서의 스펙트럼 레벨은 해중소음이 각각 86, 75, 61, 32dB, 선박진동소음이 각각 105, 95, 86, 55dB로서 후자가 전자보다 20dB 정도 높았다. 200m층에 있어서는 전자가 80, 68, 47, 26dB, 후자가 82, 70, 59, 31dB로서 후자가 전자보다 4dB 정도 높았다.

• 한국환경보건학회지
• /
• 제8권1호
• /
• pp.13-23
• /
• 1982

This Study was designed to investigate Traffic condition, Traffic Noise level, Traffic Noise Index (TNI) and Response for dissatisfactions of residents as part of assesment of Noise by 12 Sites in Seoul from July 1st to the end of August 1981. As the resut of this Study, the following Conclusion were obtained 1. The mean traffic Volume of Seoul was 3076/hour ranging 1440/hour to 5772/hour. 2. The range of Road Traffic Noise Level in Residential area was from 73.0dB (A) to 80.2dB (A). The highest level was 80.2dB (A) on Heugseog-dong and the lowest level was 73.0dB (A) on Suyu-dong. 3. Comparision of Road traffic noise level in the day and evening, the range of traffic noise level in day was from 73.9dB (A) to 80.2dB (A), and evening was ranging 73.0 to 79.9dB (A). 4. The range of TNI in Residential area was from 77.5 to 100.0. The highest TNI was 100.0 on Suyu-dong including Heugseog-dong, the lowest TNI was 77.5 on Hyuikyung-dong. 5. Respose of Noise by 360 householders has been examined in Residential Area: Sourse of Noise Causing bothersome to residents was 52.5% of traffic, the types of road traffic Cousing annoyance to residents residents were 84.8% of passing cars and 81.1% of horns, and 71.7% of reading interfered and 68.1% appeal dissatisfactions due to the sleeping disturbance by road traffic noise.