• 대한기계학회논문집B
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• 제22권4호
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• pp.468-480
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• 1998

The temporal and spatial distributions of soot volume fractions were measured for single toluene droplet flames as a function of pressure under the normal-gravity condition. In order to characterize the transient nature of the flame and sooting regions, a full-field light extinction and subsequent tomographic inversion technique was used. The reduction in sooting as a function of pressure was assessed by comparison of the maximum soot volume fractions at several vertical positions along the axis above the droplet. The maximum soot volume fraction was reduced by 70% when the pressure was reduced by 60% from 1 atm to 0.4 atm. The reduction in sooting is attributed to variation of the geometric configuration of flame which reduces the system Grashof number as well as only the change in the adiabatic flame temperature as the pressure decreases. The gravimetrically-measured total soot yield was also compared to the optically-measured soot volume fraction to obtain a correlation between the two measurements. As a result, the total soot yield was linearly proportional to the optically-measured maximum soot volume fraction and linearly reduced as the pressure decreased. Accordingly, the non-intrusive full-field light extinction-measurements were able to be calibrated not only to measure soot volume fraction, but to simultaneously evaluate the total soot yield emitted from the toluene droplet flame (which is useful in the practical application).

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 춘계학술발표회 논문집
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• pp.215-218
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• 2003

There are lots of ways to measure earth-volume, but recently Total Station and GPS are more frequently used. According to the advance of science, acquisition and processing of image by camera are also going to make great progress. So that, in this study, we search the efficiency for earth-volume calculation using digital photogrammetry.

• 한국의상디자인학회지
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• 제10권2호
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• pp.79-89
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• 2008

The purpose of this study is to evaluate the differences among visual images under variations in shoulder length and puff volume of the puff sleeve blouse. The stimuli are 21 samples: three variations of shoulder length and seven variations of puff volume. The data has been obtained from 40 fashion design majors, where they had been analyzed through frequency, factor analysis, ANOVA, Scheffe's test and MCA method. The results of the study are as the following: As a result, through factor analysis of the visual images according to the variation of shoulder point and puff volume, the following four factors had been identified. Factor 1 is the brightness from evaluation terms such as childish-precocious, cute-mature, bright-genteel, soft-hard, enlarged-reduced, particular-ordinary, interesting- uninteresting, etc. Factor 2 is the attractiveness from evaluation terms such as refine-rustic, stylish-dull, attractive-unattractive, modern-classic, urban-rural, cool-gloomy, spacious-tight. etc. Factor 3 is the comfortness from evaluation terms such as comfort-discomfort, intense-indistinct, etc. Factor 4 is the elegance from evaluation terms such as elegance-shallowness, womanish-manly, etc. These four factors were 66.7% of the total variables. Of the total variables, the first factor had been evaluated as brightness in 26.2%, attractive in 21.0%, comfortness in 11.1%, and elegance in 8.4%. From this study, the more puff volume and shorter shoulder length, the puff volume wrapped the shoulder naturally, thus making the shoulder look narrow, and giving a cute and bright image. However, by having less puff volume and excessively short shoulder length, the puff volume did not naturally wrap the shoulder, which gave an unnatural and unattractive feel.

• Clinical and Experimental Reproductive Medicine
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• 제50권4호
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• pp.262-269
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• 2023

Objective: The aim of this study was to compare semen parameters and sperm DNA fragmentation (SDF) and explore the relationship between semen parameters and SDF between 2 and 7 days of abstinence and a short abstinence period (within 4 hours) in oligozoospermic infertile patients. Methods: Two semen samples were collected from infertile oligozoospermic men (n=34) after an abstinence period of 2 to 7 days and within 4 hours, respectively. Sperm parameters were compared between the two abstinence duration groups, including semen volume, sperm concentration, total sperm count, sperm motility, total motile sperm count (TMSC), morphology, and SDF. Results: The semen volume, concentration, and total sperm count were significantly decreased after 4 hours of abstinence than after 2 to 7 days of abstinence, with median differences of 1.2 mL (p<0.001), 2×10⁶/mL (p=0.011), and 9.6×10⁶/ejaculation (p<0.001), respectively. TMSC was significantly lower after a short abstinence, with a median difference of 4.24×10⁶/ejaculate (p<0.001). However, there were no significance differences in the percentage of motility, the SDF, and the percentage of sperm with normal morphology. Interestingly, volume, concentration, total sperm count, sperm motility, and SDF, but not TMSC, exhibited significant linear correlations between the two abstinence groups in univariate regression analysis, except for TMSC. Conclusion: In oligozoospermic men, the volume, concentration, and total sperm count were significantly lower after a short abstinence period, but without adverse effects on sperm motility and SDF.

• Nutrition Research and Practice
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• 제5권3호
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• pp.236-245
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• 2011

This study investigated the correlation between consumption of sugar intake by fifth grade students in primary schools and development of Attention Deficit Hyperactivity Disorder (ADHD). A total of 107 students participated, and eight boys and one girl (8.4% of the total) categorized as high risk for ADHD according to diagnostic criteria. There were significant differences in the occupations and drinking habits of the respondents' fathers between the normal group and risk group. In a comparison of students' nutrition intake status with daily nutrition intake standards for Koreans, students consumed twice as much protein as the recommended level, whereas their calcium intake was only 60% of the recommended DRI (dietary reference intake). Regarding intake volume of vitamin C, the normal group posted 143.9% of the recommended DRI, whereas the risk group showed only 65.5% of the recommended DRI. In terms of simple sugar intake from snacks, students in the normal group consumed 58.4 g while the risk group consumed 50.2 g. These levels constituted 12.5% of their total daily volume of sugar intake from snacks, which is higher than the 10% standard recommended by the WHO. In conclusion, children who consumed less sugar from fruit snacks or whose vitamin C intake was less than RI was at increased risks for ADHD (P < 0.05). However, no significant association was observed between total volume of simple sugar intake from snacks and ADHD development.

• 콘크리트학회논문집
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• 제15권2호
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• pp.345-351
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• 2003

The transport characteristics of deleterious ions such as chlorides depend on the pore structures of concrete and are the major factors in the durability of concrete structures in subjected to chloride attack such as in marine environments. In this paper, the effect of the pore structure on compressive strength and chloride diffusivity of concrete was investigated. Six types of concretes were tested. The pore volume of concrete containing mineral admixtures increased in the range of 3∼30nm due to micro filling effect of hydrates of the mineral admixtures. There was a good correlation between the median pore diameter, the pore volume above 50nm and compressive strength of concrete, but there was not a significant correlation between the total pore volume and compressive strength. The relationship between compressive strength and chloride diffusivity were not well correlated, however, pore volume above 50nm were closely related to the chloride diffusion coefficient.

• 한국재료학회지
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• 제28권1호
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• pp.62-67
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• 2018

Active clay, bentonite and zeolite were used as porous materials for humidity controlling ceramic boards. The specific area and the pore volume of active clay were higher than bentonite and zeolite. The flexible strength of the gypsum board decreased with an increasing amount of porous material, and the flexible strength was lowest when active clay with a higher specific surface area than others porous materials was added. The specific surface area and total pore volume of ceramic boards containing porous material were highest at $102.25m^2/g$, $0.142cm^3/g$, respectively, when the active clay was added. In addition, as the amount of added porous materials increased, the specific surface area and total pore volume of the ceramic board increased, but the average pore diameter decreased. The addition of s porous materials with a high specific area and a large pore volume improved the moisture absorptive and desorptive performance of the ceramic board. Therefore, in this experiment, the moisture absorptive and desorptive properties were the best when active clay was added. Furthermore, as the amount of added porous materials increased, the moisture absorptive and desorptive properties improved. When 70 mass% of active clay was added to ${\alpha}$-type gypsum, the hygroscopicity was the highest, about $300g/m^2$, in this experiment.

• 환경영향평가
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• 제11권4호
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• pp.271-280
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• 2002

The purpose of this study is to explore the hydrological impacts and soil loss variation due to the land use change of Namak New Town development area. The analysis of hydrological effects and soil loss variation has been carried out using GIS in this study. In order to estimate the peak runoff volume, the Rational Method which is the most popular technique to predict runoff amounts is used. To estimate the soil loss in the study area, Universal Soil Loss Equation(USLE), which is one of the most comprehensive and useful technique to predict soil erosion is adopted. The result of this study has shown that the peak runoff volume and the total soil loss increase according to the land use change. The peak runoff volume and the total soil loss have been increased about 2 times and about 48 times more than that of pre development. The increasing of the peak runoff volume can be effective erosion, flooding and so on. A careful city planning is the first essential step to minimize the environmental impacts and to construct the ecological city.

• Nuclear Engineering and Technology
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• 제29권3호
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• pp.218-228
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• 1997

Correlations between the amount of DAW (Dry Active Waste) generated from present Korean PWRs and their operating parameters were analyzed. As the result of multi-variable linear regressions, a model predicting the volume of DAW using the number of shutdowns ( $f_{FS}$ ) and total personnel exposure ( $P_{\varepsilon}$) was derived. Considering one standard error bound, the model could successfully simulate about 8575 of the real data. In order to predict the amount of DAW to be generated from a KNGR another model was derived by taking into account the additional volume reduction by supercompaction system. In addition, the volume of WAW (Wet Active Waste) to be generated from KNGR (Korean Next Generation Reactor) was calculated by considering conceptual design data and replacement effect of radwaste evaporator with selective ion exchangers. Finally, total volume of SRW (Solid Radioactive Waste) to be generated from KNGR was predicted by inserting design goal values of $f_{FS}$ and $P_{\varepsilon}$ into the model. The result showed that the expected amount of SRW to be generated from KNGR would be in the range of 33~44㎥. $y^{-1}$ . It was proved that the value would meet the operational target of KNGR proposed by KEPCO, that is, 50㎥. $y^{-1}$ .

• 한국의학물리학회지:의학물리
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• 제11권1호
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• pp.85-90
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• 2000

방사선치료에서 치료의 효과는 총선량, 치료회수, 1회 조사선량 등에 의해서 결정된다. 선량강도조절법을 사용하여 방사선치료를 행할 때 치료회수나 1회 조사선량을 고려하여 총선량에 미치는 효과를 살펴보고자 한다. 방사선치료의 목적은 암조직에는 충분한 선량을 조사하면서 주위 정상 조직에는 최소한의 선량을 조사되게 하여 치료성적의 향상으로 암환자의 생존율과 삶의 질을 높이는데 목적이 있다. 이러한 문제를 해결하기 위하여 많은 연구자들이 여러 가지 방법으로 해결하고자 노력한 결과 CT의 영상을 치료계획에 이용할 수 있게 되어 three dimensional conformal radiation therapy(3DCRT)를 개발하였다. 선량강도조절법을 시행하여 총선량을 75, 80, 85, 90Gy를 조사할 때, 처음부터 선량강도조절법을 사용하여 치료하는 경우와 일차적으로 45Gy를 조사하고 boost를 조사할 때 나머지 선량을 선량강도조절 법으로 사용하는 것을 TDF 환산법을 사용하여 비교하였다. 처음부터 선량강도조절법으로 치료할 경우에는 총선량에서 약 12.5 - 15 Gy 정도 감해서 조사하여야 하는 것으로 나타났다.