• 한국철도학회논문집
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• 제10권5호
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• pp.492-498
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• 2007

곡선통과 새마을호 열차의 주행안전성을 평가하기 위하여 다물체동력학 해석모델이 사용된다. 이 모델과 ADAMS/Rail 사용하여 탈선계수와 관련된 변수의 변화에 따른 민감도해석이 수행된다. 저속에서 우측차륜의 탈선계수와 윤중감소율이 좌측차륜보다 높으나, 고속의 경우는 좌측차륜이 우측차륜보다 높다. 곡선반경의 감소에 따라 탈선계수와 윤중감소율이 감소된다. 완화곡선의 길이가 증가하면 탈선계수는 증가하나 윤중감소율은 변화가 없다. 캔트가 증가하면 탈선계수와 윤중감소율이 증가한다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권1호
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• pp.71-77
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• 2017

Objective: This experiment was conducted to investigate the effects of dietary supplementation with marigold extract on growth performance, pigmentation, antioxidant capacity and meat quality in broiler chickens. Methods: A total of 320 one-day-old Arbor Acres chickens were randomly divided into 5 groups with 8 replicates of 8 chickens each. The chickens of control group were fed with basal diet and other experimental groups were fed with basal diet supplemented with 0.075%, 0.15%, 0.30%, and 0.60% marigold extract respectively (the corresponding concentrations of lutein were 15, 30, 60, and 120 mg/kg). Results: The results showed that marigold extract supplementation increased the yellowness values of shank, beak, skin and muscle and the redness ($a^*$) value of thigh muscle (linear, p<0.01). Marigold extract supplementation significantly increased the total antioxidant capacity, and the activities of superoxide dismutase in liver and thigh muscle (linear, p<0.01) and significantly decreased the malondialdehyde contents of liver and thigh muscle (linear, p<0.01). Marigold extract supplementation significantly decreased the drip loss and shear force of thigh muscles (linear, p<0.01). There was no significant effect on growth performance with marigold extract supplementation. Conclusion: In conclusion, dietary supplementation of marigold extract significantly increased the yellowness values of carcass, antioxidant capacity and meat quality in broiler chickens.

• 대한건축학회논문집:계획계
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• 제35권7호
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• pp.109-117
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• 2019

Recently, child safety map making education has attracted attention as a way to reduce crimes against children. In Korea, the Ministry of Gender Equality and Family organized a child safety map making education program in 2011. The program's manual was revised in 2013 and the Ministry implemented it as a project to promote the rights of women and children. Child safety map making education aims to raise a child's understanding of their neighborhood, to have voluntary control and normal consciousness as a local inhabitant, to be aware of wrong behavior and crime, and to be part of creating a safe urban environment. However, when compared to educational programs in other major developed countries, the child safety map making education program in Korea currently does not improve a child's awareness of their surroundings. In this workshop study, we proposed and ran a new program to improve children's awareness of their environment based on the active participation of children in the existing safety map educational program. The workshop was held for 4 weeks for 48 students from 5th and 6th grade at Osan Daeho Elementary School. We analyzed this new program's effects with the following results. First, an analysis of the effects of the program on children's recognition of safe and dangerous spaces revealed that their understanding of these spaces increased by 30.4% after the workshop. The safety-related factor in the mind map key concept increased from 0.94 to 4.94, indicating that the children's perception of neighborhood risk and safety factors improved. Second, the analysis of the effects of the program on the children's coping ability in dangerous situations showed that their understanding of how to deal with dangerous situations increased by 11.3%. The children's understanding of facilities they could ask for help, such as police boxes and child safety guard houses, improved by 17.9%. Third, analysis of the effects of child safety map making education on children's understanding of their neighborhood, their perception of responsibility in the neighborhood, and their neighborhood attachment showed that these levels of children's understanding of the neighborhood improved by 6.0% after the workshop.

• Nuclear Engineering and Technology
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• 제48권2호
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• pp.518-524
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• 2016

The thermal aging effects on mechanical properties and microstructures in China low-activation martensitic steel have been tested by aging at $550^{\circ}C$ for 2,000 hours, 4,000 hours, and 10,000 hours. The microstructure was analyzed by scanning and transmission electron microscopy. The results showed that the grain size and martensitic lath increased by about $4{\mu}m$ and $0.3{\mu}m$, respectively, after thermal exposure at $550^{\circ}C$ for 10,000 hours. MX type particles such as TaC precipitated on the matrix and Laves-phase was found on the martensitic lath boundary and grain boundary on aged specimens. The mechanical properties were investigated with tensile and Charpy impact tests. Tensile properties were not seriously affected by aging. Neither yield strength nor ultimate tensile strength changed significantly. However, the ductile-brittle transition temperature of China low-activation martensitic steel increased by $46^{\circ}C$ after aging for 10,000 hours due to precipitation and grain coarsening.

• 대한영양사협회학술지
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• 제28권3호
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• pp.182-194
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• 2022

After the onset of the COVID-19 pandemic, there has been an explosive increase in restaurant meal delivery or takeout. The purpose of this study was to analyze the consumer perception of food safety and its influence on the purchase of delivery or takeout food from restaurants. This study, the 2020 Consumer Behavior Survey for Food (CBSF), was conducted from June 10 to August 21 2020. A total of 6,355 responses were used for the analysis. The results were as follows: First, the differences in consumer perception about food safety were analyzed according to whether they used delivery or takeout. Concern about food safety, satisfaction with dietary habits, and the ability to maintain safe dietary habits were higher in the non-user group. Except for food at home, the perception about food safety at other locations was higher in the user group. Food hazards such as antibiotics were perceived to be safer in the user group. Second, the perception of food safety affecting use of delivery or takeout was analyzed. It was found that the usage of delivery or takeout increased when the perception of the safety of home meal replacement (HMR), delivery or takeout food, and the ability to be informed about the harmful factors of agricultural products increased. The findings of this study may offer the basis for the food and food service industry to consider safety issues seriously and develop strategies to lead to feasible practices. Further, this study also supports the direction of the government toward strengthening the safety of new segments which have shown explosive growth in the COVID-19 era.

• 자동차안전학회지
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• 제8권3호
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• pp.16-21
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• 2016

As motorcycles are getting more widely used recently, motorcycle accidents are gradually increased every year. Although most accidents are caused by human factors, the importance of motor vehicle safety standards cannot be underestimated indeed. A variety of regulations related to motorcycle safety have been issued in many countries such as EU, U.S., and Australia, etc. In order to harmonize the international safety standards, it is necessary to develop or enhance the Korean Motor Vehicle Safety Standards (KMVSS) for motorcycles. In this study, motorcycle safety standards for an exterior rear-view mirror and a tire are investigated. Actual test procedures are expected in sequential studies according to the results provided herein. Also, the findings in this paper can be utilized to ensure the KMVSS for a safer driving.

• 한국안전학회지
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• 제20권2호
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• pp.1-5
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• 2005

An experimental study was conducted to develop an understanding of failure of ceramic coating when subjected to a thermal cycling. Number of cycles to failure were decreased as the coating thickness and the oxide of bond coat were increased. Using the finite element method, an analysis of stress distribution in ceramic coatings was performed. Radial compressive stress was increased in the top/bond coat interface with increasing coating thickness and oxide of bond coat.

• 한국안전학회지
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• 제9권3호
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• pp.67-73
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• 1994

The gas holdup and volumeteric liquid phase mass transfer coefficient with the variation of the concentration of CMC aqueous solution, gas velocity, diameter and area of the draught tube were investigated. As the results of the experiments, the gas holdup and volumetric liquid phase mass transfer coefficient decreased with decreasing the concentration of CMC aqueous solution, increased with increasing the gas velocity and increased with increasing the circulated area ratio of the draught tube.

• 대한안전경영과학회지
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• 제4권3호
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• pp.35-43
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• 2002

For the unconfined vapor cloud explosion accident by the continuous release of gas-liquid flow of various saturated liquids in a vessel at ground level, overpressures were estimated and analyzed with various release conditions and materials by TNT equivalency model with vapor dispersion. We found that at same release conditions, overpressure showed n-heptane > xylene > n-hexane > toluene > n-heptane > benzene, respectively and that overpressure was increased with increasing the hole diameter and the storage pressure, but it was increased with decreasing the wind speed, the interested distance, and the vessel thickness.

• 대한안전경영과학회지
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• 제3권4호
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• pp.45-52
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• 2001

In order to Investigate water tree degradation behavior on XLPE cable, direct voltage of 200 to 800V has been applied to the material at 5$0^{\circ}C$~10$0^{\circ}C$, and the water tree property has been correlated with voltage and temperature. The leakage current was increase as temperature increased and the Ohm's law was generally satisfied in this experiment though some experimental errors were found. The leakage current was decreased and reached to the stable state with time. It was also shown that the time for the stabilization of leakage current was lessened as voltage increased