• Current Optics and Photonics
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• 제8권3호
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• pp.246-258
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• 2024

In aerospace and energy engineering, the reconstruction of three-dimensional (3D) temperature distributions is crucial. Traditional methods like algebraic iterative reconstruction and filtered back-projection depend on voxel division for resolution. Our algorithm, blending deep learning with computer graphics rendering, converts 2D projections into light rays for uniform sampling, using a fully connected neural network to depict the 3D temperature field. Although effective in capturing internal details, it demands multiple cameras for varied angle projections, increasing cost and computational needs. We assess the impact of camera number on reconstruction accuracy and efficiency, conducting butane-flame simulations with different camera setups (6 to 18 cameras). The results show improved accuracy with more cameras, with 12 cameras achieving optimal computational efficiency (1.263) and low error rates. Verification experiments with 9, 12, and 15 cameras, using thermocouples, confirm that the 12-camera setup as the best, balancing efficiency and accuracy. This offers a feasible, cost-effective solution for real-world applications like engine testing and environmental monitoring, improving accuracy and resource management in temperature measurement.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1553-1561
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• 2024

Nondestructive radiography using cosmic ray muons has been used for decades to monitor nuclear reactor and spent nuclear fuel storage. Because nuclear fuel assemblies are highly dense and large, typical radiation probes such as x-rays cannot penetrate these target imaging objects. Although cosmic ray muons are highly penetrative for nuclear fuels as a result of their relatively high energy, the wide application of muon tomography is limited because of naturally low cosmic ray muon flux. This work presents a new image reconstruction algorithm to maximize the utility of cosmic ray muon in tomography applications. Muon momentum information is used to improve imaging resolution, as well as muon scattering angle. In this work, a new convolution was introduced known as M-value, which is a mathematical integration of two measured quantities: scattering angle and momentum. It captures the objects' quantity and density in a way that is easy to use with image reconstruction algorithms. The results demonstrate how to reconstruct images when muon momentum measurements are included in a typical muon scattering tomography algorithm. Using M-value improves muon tomography image resolution by replacing the scattering angle value without increasing computation costs. This new algorithm is projected to be a standard nondestructive radiography technique for spent nuclear fuel and nuclear material management.

• 한국지반신소재학회논문집
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• 제18권4호
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• pp.53-61
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• 2019

북극권에는 미개발된 막대한 에너지·자원이 매장되어 있다. 지구온난화로 인해 북극 항로의 이용이 가능해지고, 자원개발에 대한 관심이 높아짐에 따라 극지 인접국들과 선진국들은 국가적 차원에서 북극권 개발과 건설 사업을 활발히 추진하고 있다. 동시에 북극권 자원 개발과 자원 이송에 따른 환경오염 문제도 꾸준히 제기되어 왔다. 오늘날 환경 문제는 북극권 개발사업의 비용뿐 아니라, 사업 자체의 성공 여부에 중대한 영향을 미치고 있다. 따라서 북극권 자원 개발사업을 위해서는 에너지·자원 개발 및 이송과 관련된 기술 확보와 함께 환경영향평가(Environmental Impact Assessment, EIA)에 대한 전략 수립이 반드시 필요하다. 본 논문에서는 북극권 자원 개발 시, 고려해야 할 환경영향평가의 특성과 절차를 살펴보고, 그에 필요한 정보를 체계적으로 관리하기 위한 시스템 구축 방안을 고찰하였다. 본 시스템은 북극권 환경영향평가에 필요한 정보 데이터베이스와 그를 활용하는 응용시스템으로 구성되며, 북극권 자원 개발사업을 위한 전략수립 등을 위하여 활용될 것으로 기대된다.

• Nutrition Research and Practice
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• 제4권4호
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• pp.317-322
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• 2010

Prevalence of childhood obesity is increasing significantly worldwide due to energy imbalance perhaps stemming from undesirable dietary behavior and physical activity level. The objective of the study was to examine the effects of physical activity level on nutritional status in elementary school students. The subjects were comprised of 287 elementary school students between 4th and 6th grades in Seoul, Korea. The level of physical activity was scored with a modified Godin leisure-time exercise questionnaire and was categorized as active, moderately active, and sedentary. Dietary intakes were obtained using a 24-hour food recall method. An analysis of variance (ANOVA) was conducted to test for global significant differences of nutrient intakes by physical activity level. Boys were more active than girls. Daily intakes of energy in moderately active boys were significantly higher than in the sedentary group, but intakes of calcium and iron in moderately active boys were lower than active boys. For girls, physical activity level did not affect nutrient density at all. Intakes of calcium, vitamin C, and folate for both boys and girls were below 50% of recommended intake. Physical activity did not affect nutrient density and our participants were exposed to nutritional imbalance. Therefore, the results suggest that nutrition education regarding balanced diet and optimum physical activity is required for children's health and growth.

• 한국환경과학회지
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• 제25권7호
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• pp.1007-1016
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• 2016

Environmental policy implementation has been strengthened to protect the source waters in Korea and to improve their water quality. Increasing of non-point source caused water quality problem continuously. Research on runoff from forests, which occupy over 65% of the land in korea, is insufficient, and studies on the characteristics and influences of storm runoff are necessary. In this study, we chose to compare the effects of land use in the form of two types of forest distribution and then gathered data on storm characteristics and runoff properties during rainfall events in these areas. Furthermore, the significance and influences of the discharges were analyzed through correlation analysis, and multilateral runoff characteristics were examined by deducing a formula through $COD_{Mn}$ and TOC regression analysis. At two forest points, for which the basin areas differed from each other, flow changed according to storm quantity and intensity. The peak discharge at point A, where the basin area was big, was high, whereas water-quality fundamental items (BOD, $COD_{Mn}$, and SS) and TOC density were high at point B where the slope and storm intensity were high. Effects of dissolved organic matter were determined through correlation analysis, and the regression formulas for $COD_{Mn}$ and TOC were deduced by regression analysis. It is expected that the data from this study could be useful as basic information in establishing forest management measures.

• Nutrition Research and Practice
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• 제8권5호
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• pp.571-579
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• 2014

BACKGROUND/OBJECTIVES: The objectives were to investigate the effect of a 12-wk intervention with behavioral modification on clinical characteristics and dietary intakes of young and otherwise healthy obese and to identify factors for successful weight loss. The goal was to lose 0.5 kg per week by reducing 300-500 kcal/day and by increasing physical activities. SUBJECTS AND METHODS: Forty four obese subjects (BMI > 25) and 19 normal weight subjects (BMI 18.5-23) finished the 12-week intervention. Obese subjects participated in 5 group educations and 6 individual counseling sessions. Normal weight subjects attended 6 individual counseling sessions for evaluations of dietary intake and exercise pattern. Anthropometric and clinical characteristics and 3-day dietary records were evaluated at baseline and week12. RESULTS: Weight and serum triglyceride and free fatty acid concentrations in obese group decreased significantly with intervention. Intakes of energy, fat, and cholesterol decreased significantly in the obese. Active participation, realistic weight loss goal setting, and weight gain after high school graduation not during childhood were identified as key factors for successful weight loss. CONCLUSIONS: The 12-week intervention with behavioral modification resulted in reduced energy and fat intakes and led to significant weight loss and improvements of clinical characteristics in the obese. The finding that those who became obese during childhood lost less weight indicates the importance of 'early' intervention.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.376-382
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• 2011

Since the Industrial Revolution has caused global change by using of a fossil fuel, a reckless and growth-oriented development. A global mean temperature since 19th century has climbed up 0.4~$0.8^{\circ}C$. Our country, afterwards, global warming has increased the temperature every season. After The Kyoto Protocol regarding a greenhouse gas reduction goal took effect, be situations that decrease of greenhouse gas was acutely required. Therefore, interest of utilization of the new & renewable energy is increasing everyday. In advanced research, we shows that at first divided a country to nine range by natural geography, and second executed Meteorological data analysis of recent 30 years considering level of significance by nine range. The results of advanced research are that the similarities are low because there are the regions that temperature deviation of the similar climate regions is large in winter season, and there are not characteristics of clear discrimination of temperature. This study shows that at first divided a country to six range by temperature range, and second executed Meteorological data analysis of recent 30 years considering level of significance by six range. The results of this study are that in heating load calculation of building, periodic temperature data management is required because facility capacity and cost are affected greatly by outdoor temperature, and temperature by climate range needs consideration of pertinent area. Ground temperature was assumed of the weather in region, the ground and soil. Lastly, we were able to know that establishment of climate region by temperature range can be useful policy making and plans of design of the horticultural facilities and architectures.

• 대한인간공학회지
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• 제30권1호
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• pp.213-220
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• 2011

Objective: The aim of this study was to investigate middle-aged drivers' driving performance and heart-rate as the behavior and physiological changes due to intersection types in left-turn situation. Background: In Korea, the drivers were aged 40~50s are most plentiful. In addition, the intersection traffic accidents are increasing every year. However, the researches for middle-aged drivers and intersection environments have been little. Method: In this study, three kinds of left-turning intersection types(T1, T2, T3) was used as the within-subject independent variables, three age groups(young, middle-aged, elderly) was used as the between-subject independent variables. Also, passing time, approaching velocity, speed and steering variations and heart-rate were used as dependent variables. Results: Overall, middle-aged drivers' driving behaviors were similar to those of the younger drivers. At the T2 intersection type, however, the approaching velocity of middle-aged drivers was similar to younger drivers, whereas the passing time of middle-aged drivers was similar to elderly drivers. Conclusion: These results could be interpreted that a transition driving behavior of middle-aged drivers in terms of age would be appeared on the T2 intersection type. Application: The results might help to understand the characteristics of driving behavior for middle-aged drivers.

• 한국자원공학회지
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• 제55권6호
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• pp.564-575
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• 2018

최근 남한과 북한의 긴장완화에 따라 남북 경제협력사업 추진 가능성이 높아지고 있다. 북한의 광산 개발 사업은 남북 경협사업으로 많은 관심을 받고 있는 상황이다. 북한 광산개발 혹은 광산분야 협력사업 추진 시 광해위험관리에 대한 고려를 해야한다. 그러나, 북한의 광해실태 정보는 부족한 상황이다. 이에 본 연구에서는 구글 어스를 활용하여 북한의 12개의 대표 광산에 대하여 광해현황를 조사하였다. 구글 어스 영상 분석 결과, 북한 지역의 광물찌꺼기 적치장 붕괴, 적화현상, 지반침하 등의 광해를 확인할 수 있었다.

• 한국위험물학회지
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• 제6권2호
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• pp.77-86
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• 2018

Interest in renewable energy is increasing for eco-friendly use of energy, and fuel cells are being used in various ways such as houses and buildings as power generation methods that have low emissions such as $NO_X$ and $CO_2$. As the supply of fuel cells expands, more and more boilers are installed in the existing buildings, but safety management is not being performed properly. Therefore, in this study, a prior study was conducted on the status of fuel cell-boiler complex installation and related criteria, and the risk factors were analyzed according to the installation environment and structure. Based on these standards, the safety performance of the fuel cell-boiler combined installation is assessed by conducting a demonstration using the starting product of the simulated operation to derive the installation criteria (proposal) for the fuel cell-boiler combined installation. The installation criteria (proposal) include the construction and connection method of the piping according to the fuel cell-boiler complex installation.