• Nuclear Engineering and Technology
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• 제54권3호
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• pp.867-876
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• 2022

An experimental study has been conducted to investigate the heat transfer characteristics of supercritical carbon dioxide (sCO₂) uniformly heated in the horizontal circular smooth tube. The results illustrated that there was a significant difference in heat transfer between the top wall and bottom wall due to the buoyancy. Bulk flow acceleration cannot be negligible in the high heat flux region, which leads to heat transfer deterioration. A new heat transfer correlation is proposed, in which the buoyancy parameter and bulk flow acceleration have been taken into account. The new correlation and six classic correlations for sCO₂ are examined in horizontal tubes. The comparison indicates that the new correlation has a better performance for sCO₂ flowing through a horizontal heating tube under natural circulation conditions. For example, 94.9% of the calculated results using the new heat transfer correlation were within ±30% of the experimental results while only 87.9% of that using the Jackson correlation (the best of the six) were within the same error bands.

• 환경영향평가
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• 제15권4호
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• pp.271-277
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• 2006

In this study, we investigated the applicable plan of GIS on the environmental impact assessment of 60 Hz Powerline. So we assessed distance data based on calculations by use of 2D and 3D Geographical information systems(GIS) and distance data based on measurements on 1: 5000 maps accord with on site distance measurements to use input data for calculating magnetic field. One hundred eight of the on site measured addresses were selected from residences. The data were achieved by measuring the distance between residence and power line on maps with scales of 1: 5000. The digital map was obtained from National Geographic Information Institute with scales of 1: 5000, and we made 2D and 3D map. Correlation analyses were performed for statistical analyses. For the 3D GIS versus on site comparison of different exposure categories, 70 of 108 measurements were assigned to the correct category. Similarly for 2D GIS versus on site comparison, 71 of 108 were correctly categorized. When comparing map measurement with on site measurement, 62 of 108 were correctly categorized. When the correlation analysis was performed, best correlation was found between 3D GIS and on site measurements with r = 0.84947 (p<0.0001). The correlation between map and on site measurement yielded an r of 0.76517 (p<0.0001). Since the GIS measurements and map measurement were made from the center point in the building and the on site measurements had to be made from the closest wall on the building, this might introduce and additional error in urban areas. The difference between 2D and 3D calculations were resulted from the height of buildings.

• 대한영양사협회학술지
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• 제17권2호
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• pp.99-117
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• 2011

The purpose of this study was to investigate weight gain during pregnancy based on pre-pregnant Body Mass Index, to compare eating habits based on the recommended standards for weight gain presented by the Institute of Medicine, and to identify factors affecting the weight gain of pregnant women. The subjects were grouped into three categories according to the recommended weight gain standards presented by the Institute of Medicine: the inadequate group, the adequate group and the excessive group. The excessive group had a significantly higher pre-pregnant Body Mass Index than that of the two other groups. Based on a comparison of the eating habits and nutrient intake of the women to the recommended standards for weight gain, the excessive gain group had large meals and ate more frequently outside of the home when compared to the pre-pregnancy period. Based on an analysis of correlations between weight gain during pregnancy and diet factors, the adequate gain group had positive correlation between weight gain and a "balanced meal" and had negative correlation with "convenience meals". The excessive gain group had a positive correlation with "convenience meals" and had a negative correlation with "meal skipping." All the pregnant women were more frequent in the "overeating categories" and all ate more "fruit," as their weight gain was higher. In particular, the excessive gain group was frequently evaluated as "overeating". These results indicate that the factors affecting weight gain during pregnancy were the Body Mass Index before pregnancy, eating types, and eating habits. As the Body Mass Index before pregnancy was higher, the ingestion of a 'balanced meal' was less, and overeating and gluttony were more frequent. Therefore weight gain was enhanced.

• 한국수자원학회논문집
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• 제48권1호
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• pp.69-78
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• 2015

본 연구는 기상학적 가뭄지수가 수문학적 가뭄에 대한 모사정도를 검토하였다. 기상학적 가뭄지수 중에서 강수량을 변수로 하는 SPI(Standardized Precipitation Index)와 강수량 및 증발산량을 변수로 하는 SPEI(Standardized Precipitation Evapotranspiration Index)를 이용하였고, 수문학적 가뭄 평가를 위하여 월 총 유입량과 하천수 가뭄지수인 SDI(Streamflow Drought Index)를 계산하여, 최종적으로 기상학적 가뭄지수와 수문학적 가뭄지수와의 상관정도를 분석하였다. 월별 상관계수 비교결과, 지속기간 270일에 기상학적 가뭄지수와 월 총 유입량과 상관정도가 가장 높아서 0.67로 나타났고 기상학적 가뭄지수로 SDI와의 상관정도는 0.72~0.87이었다. 연별 극한값을 비교한 결과, 월 총 유입량의 최저값과 기상학적 가뭄지수의 연관성은 거의 확인되지 않았다. 다만 SDI와 SPEI가 매우 높은 상관정도를 보였다. 기상학적 가뭄지수로 수문학적 극한가뭄에 해석하는 데에 한계가 있는 만큼 수문 가뭄해석이 목적이라면 유량자료가 직접 활용될 수 있는 가뭄지수가 필요하다.

• Clinics in Shoulder and Elbow
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• 제21권1호
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• pp.15-21
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• 2018

Background: This study was undertaken to compare the outcome of supervised and home exercises with respect to range of motion (ROM), pain, and Single Assessment Numeric Evaluation (SANE). We further correlated the ROM recovery and pain reduction as well. Methods: The study included 49 patients who underwent arthroscopic rotator cuff repair. Rehabilitation was initiated after 4 weeks of immobilization. A total of 29 patients performed supervised exercise 3 times a week. Standardized education and brochures for review were provided to the remaining 20 patients who insisted on home rehabilitation. Statistical analysis was performed for comparing pain Numerical Rating Scale (NRS), SANE, and ROM. In addition, we also evaluated the correlation between pain and ROM. Results: Comparison of the two groups revealed no significant differences in forward flexion, internal rotation, abduction, and pain NRS. However, SANE at the 9th week (63.8 vs. 55.0, p=0.038) and improvement of external rotation from the 5th to the 9th week (17.6 vs. 9.3, p=0.018) were significantly higher in the supervised exercise group as compared to the home exercise group. Correlation of pain NRS with forward flexion, external rotation, internal rotation and abduction were statistically not significant (correlation coefficient=0.032 [p=0.828], -0.255 [p=0.077], 0.068 [p=0.642], and -0.188 [p=0.196], respectively). Conclusions: The supervised rehabilitation after arthroscopic rotator cuff repair showed better improvement in external rotation and higher SANE score after 4 weeks of rehabilitation exercise. However, no statistically significant correlation was observed between the recovery of ROM and short-term pain relief.

• 디자인학연구
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• 16호
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• pp.77-86
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• 1996

한국인의 색채감정에 맞는 효율적인 색채계획이 이루어지기 위해서는, 먼저 한국인의 색채감정의 고유성 확인이 필요하다고 생각된다. 이에 인국(隣國)인 일본과의 비교를 통한 한국인의 색채 기호의 고유성을 확인하기 위하여, PCCS 에 대한 한${\cdot}$일 대학생의 색채기호를 조사하였다. 조사결과는 다음과 같다. 1. 한${\cdot}$일 양국의 대학생이 가장 기호하는 색은 비비드 블루이고, 가장 혐오하는 색은 그레이쉬 브라운이다. 2. 한국 대학생이 가장 기호하는 색은 퍼프 블루이고, 일본 대학생이 가장 기호하는 색상은 블루이다. 한${\cdot}$일 양국의 대학생이 가장 혐오하는 색상은 옐로우 레드 이다. 3. 한${\cdot}$일 양국의 대학생이 가장 기호하는 톤은 비비드 이고, 가장 혐오하는 톤은 그레이쉬 이다. 4. 한${\cdot}$일간의 색채기호의 상관관계를 비교해 보면, 색상보다는 톤에 있어서의 강한 상관관계를 나타내었다.

• Korean Journal of Radiology
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• 제22권2호
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• pp.243-252
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• 2021

Objective: To compare and correlate the findings of intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging and arterial spin labeling (ASL) imaging in characterizing parotid gland tumors. Materials and Methods: We retrospectively reviewed 56 patients with parotid gland tumors evaluated by MR imaging. The true diffusion coefficient (D), pseudo-diffusion coefficient (D^*), and fraction of perfusion (f) values of IVIM imaging and tumor-to-parotid gland signal intensity ratio (SIR) on ASL imaging were calculated. Spearman rank correlation coefficient, chi-squared, Mann-Whitney U, and Kruskal-Wallis tests with the post-hoc Dunn-Bonferroni method and receiver operating characteristic curve assessments were used for statistical analysis. Results: Malignant parotid gland tumors showed significantly lower D than benign tumors (p = 0.019). Within subgroup analyses, pleomorphic adenomas (PAs) showed significantly higher D than malignant tumors (MTs) and Warthin's tumors (WTs) (p < 0.001). The D^* of WTs was significantly higher than that of PAs (p = 0.031). The f and SIR on ASL imaging of WTs were significantly higher than those of MTs and PAs (p < 0.05). Significantly positive correlation was found between SIR on ASL imaging and f (r = 0.446, p = 0.001). In comparison with f, SIR on ASL imaging showed a higher area under curve (0.853 vs. 0.891) in discriminating MTs from WTs, although the difference was not significant (p = 0.720). Conclusion: IVIM and ASL imaging could help differentiate parotid gland tumors. SIR on ASL imaging showed a significantly positive correlation with f. ASL imaging might hold potential to improve the ability to discriminate MTs from WTs.

• 가정과삶의질연구
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• 제26권4호
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• pp.73-83
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• 2008

This study examines the effects of mass media, the tendency for young women to make body comparisons, and the BMI of female high school and college students on their attitudes about eating. Participants were 392 high school students from Gyeonggi Province and 391 college students from Seoul, Gyeonggi and Chung-nam Province. Collected data were analyzed through Cronbach's ${\alpha}$, t-test, One-way ANOVA, $Scheff{\acute{e}}$ test, Pearson's correlation, and stepwise multiple regression. The findings of the study were as follows: 1) While mass media influence differed by grade, tendency for appearance comparison and attitude toward eating did not differ by grade. 2) Mass media influence, tendency for appearance comparison and attitude toward eating differed by BMI. 3) Mass media pressure, specific attributes comparison, and BMI were significant predictors of attitudes toward eating. 4) Tendency for appearance comparison played a mediating role in the relationship between mass media and attitudes toward eating.

• 한국융합학회논문지
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• 제8권1호
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• pp.1-6
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• 2017

본 논문은 7개 안테나로 구성된 원형배열 안테나에 전파가 입사될 때 안테나 상호간의 계산 위상차와 시험 환경에서 측정한 위상차를 데이터 융합하여 전파의 도래 방향을 탐지하는 상관형(correlative) 위상비교 방향탐지에 대하여 기술하였다. 상관형 위상비교 방식은 균일원형배열(UCA: uniform circular array)과 선형 배열 방식이 많이 사용되며, 수식적으로 계산한 위상차 데이터와 시험 환경에서 측정한 위상차 데이터를 상관함수로 데이터 융합하여 전파 입사 방위각을 계산하므로 현재 많이 사용되고 있는 측정위상차비교 방향탐지 방식보다 성능이 우수하다. 수신신호의 신호잡음비(SNR)가 20dB이고 수신신호의 파장에 대한 안테나 상호간 거리($L/{\lambda}$)가 0.5인 경우 상관형 방탐은 방향탐지 정확도가 $1.7^{\circ}$ 로 나타나서 측정형 위상비교인 경우 $2.5^{\circ}$ 이상인 것과 비교하여 우수한 것이 확인되었으며 전자파신호 감시용, 군사용 방향탐지용에 사용될 수 있을 것으로 판단된다.

• 한국생활과학회지
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• 제19권4호
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• pp.675-685
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• 2010

This study analyzed risk perception and risk reduction behaviors of male and female college students in their twenties who purchased fashion products in internet shopping malls. It also investigated the relationship between risk perception and risk reduction behavior as well as the ways in which groups, categorized by risk perception, differed in their risk reduction behaviors. The results of this study were as follows: first, seven factors of risk perception were identified. These were product quality, shipping, product image, payment, economic feasibility, fear of other people's reactions, and size. Six types of risk reduction behavior were also identified. These were product comparison, word-of-mouth information search, price search, preference for name-brand, service comparison, and referring to experiences. Next, a correlational analysis of the factors of risk perception and those of risk reduction behavior showed several patterns. The highest positive correlation was between economic risk perception and product comparison behavior. In addition, shipping risk perception was positively correlated with service comparison behavior and product quality and product image had a positive correlation with word-of-mouth information search behavior. Third, customers of internet shopping malls could be categorized into three groups: shipping risk perception group, high risk perception group, and product quality risk perception group. The groups were shown by factor analysis to be significantly different to each other. Finally, risk reduction behavior was investigated according to the different groups of risk perception of the internet shopping malls and the results showed significant differences among groups.