• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.110-113
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• 2002

가상환경시스템은 매우 현실감 있는 정보를 제공할 수 있다는 점에서 산업, 의료, 교육훈련 등에 널리 사용되고 있다. 그러나 아직 많은 가상환경 시스템에서 부정적 요인으로 멀미나 시각피로로 대표되는 cybersickness 증세를 수반하고 있어 그 사용과 확산에 제약이 되고 있다. 한편 cybersickness 의 한 현상으로 볼 수 있는 신체동요도 이에 대한 객관적 지표로서의 가능성이 연구되어지고 있다. 본 연구에서도 가상환경시스템을 피실험자들에게 체험하게 하고 체험 전후의 신체동요으 변화를 측정평가 하였다. 측정 결과 가상환경 체험 후 약간의 신체 동요의 경향이 나타났으나 통계적으로 유의할만한 정도의 차이는 보이지 못했다. 특히 본 연구에서 신체동요의 변인으로 가정했던 Motion의 유무와 Feedback 의 유무에 대한 영향 분석 결과에서도 좌우 방향에 대한 Motion 유무만 차이를 보였을 뿐이었다. 신체동요는 비교적 간단히 객관적으로 cybersickness의 일면을 평가할 수 있는 지표로 후속 연구가 계속 요청되고 있다.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.1004-1013
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• 2012

3D images and videos are required viewers to wear 3D glasses. According to the data, about half of Korean people wear glasses or contact lens and this implies 3D video viewers may have a trouble due to putting a pair of 3D glasses atop their glasses. The purpose of this study is to examine gamers' perceived characteristics, presence, and fatigue according to video gaming display (2D vs. 3D) and glasses whether wearing or not. The results show that the interaction effect of the display and wearing glasses was statistically significant in the perceived presence, and the main effect of the display was statistically significant in the perceived characteristics and fatigue.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1482-1491
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• 2013

The purpose of this study was to investigate the safety accidents and physical fatigues of school foodservice employees. Out of 300 questionnaires distributed from December 1~20, 2011, 276 responded. After excluding 54 incomplete questionnaires, 222 (usage rate: 74%) were examined in the final analysis. First, our results showed that in terms of safety accidents, most received bruises (92.8%), followed by burns (73.0%), cuts and lacerated wounds (69.4%), sprains (47.7%), falls (42.8%), fractures/dislocations (31.5%) and electric shock (2.7%). Second, we found that the average degree of physical fatigue of school foodservice employees was 3.65 based on the 5-point Likert scale. Specifically, pain in the arms and wrist was rated the highest, at 4.18. Third, results showed that the factors affecting physical fatigue were 'class of school' (P<0.05), 'frequency of meal serving per day' (P<0.05), 'no. of meals served per day' (P<0.001), 'no. of meals per employee' (P<0.05) and 'warm-up exercise before starting work' (P<0.05). This means that foodservice employees serving middle schools, serving meals three times per day, serving more than 1,000 meals per day, and serving more than 111 meals per employee perceive higher levels of physical fatigue. In addition, the physical fatigue of those who perform warm-up exercises before starting work was significantly lower than those who do not perform warm-up exercises before work (P<0.05). In conclusion, the frequently occurring major safety accidents of school foodservice employees were bruises and burns. An increase in workload also leads to the increasing physical fatigue of school foodservice employees. Thus, to lower the physical fatigue of school foodservice employees, school foodservice employees should be encouraged to perform warm-up exercises before staring work and new staffing guidelines for school foodservice employees should be developed.

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.53-62
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• 2001

Effects of surface defect on thermal stability and stress crack resistance of high density polyethylene geomembranes in environmental conditions were examined by comparing the mechanical properties, chemical resistance and failure times of geomembranes between defective cases under different temperatures. Artificial surface defects were added to the surface of geomembranes by scratch apparatus designed specially. The number of surface defects was increased with the smaller size of scratch induced particles, and the more scratch addition numbers at the shear rate of scratch induced mechanism, 100mm/min. The tensile strength were decreased but the tensile strain was increased with the above conditions. In chemical resistance of defective geomembranes, the tensile strength were decreased but the tensile strain was increased with the longer immersion period and the higher temperature under the same scratch induced conditions. Finally, failure times of defective geomembranes by ESCR test were shifted to the shorter time ranges by increasing temperatures.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.67-74
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• 2020

This study was a correlational study between the violence experience and post-traumatic stress disorder, compassion fatigue, and job satisfaction of emergency room nurses. The researcher conducted this study on 114 randomized emergency room nurses from 9 emergency rooms located in Gyeonggi-do and collected data for approximately 4 weeks from July 1, 2019 to July 31, 2019. The mean values of verbal violence showed 11.50±3.37 points, physical threatening showed 11.57±4.15 points, and physical violence showed 11.07±5.20. In this study, the mean values of post-traumatic stress disorder was 34.59±14.46 points, compassion fatigue was 26.50±7.17, and job satisfaction was 61.19 ± 8.38 points. Multiple linear regression indicated that post-traumatic stress disorder (β=-.21, p=.009) respectively predicted job satisfaction(F=23.11, p<.001) Based on the study results above, it is considered that programs that can systematically manage and prevent post-traumatic stress disorder and compassion fatigue are required to reduce post-traumatic stress disorder, and compassion fatigue from violence experience of emergency room nurses. Moreover, safe work environments should be established to work efficiency.

• Science of Emotion and Sensibility
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• v.17 no.2
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• pp.55-62
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• 2014

In this study, a questionnaire was developed to assess error search and correction tasks, and an analysis was performed on the accuracy of the tasks and the time required for their completion in order to identify the effects of LED light source illumination on visual performance according to changes in a predicted mean vote(PMV) thermal environment. In addition, a subjective evaluation was performed by conducting a survey on the level of visual fatigue experienced during the tasks. In the experiment, four types of PMV thermal environments were established according to PMV values in the temperature range of $(17{\pm}1-29{\pm}1)^{\circ}C$ and the humidity range of $(50{\pm}5-60{\pm}5)%$, and the LED light source illumination was divided into three types: 400lx, 700lx, and 1000lx. The experimental results confirmed that the accuracy of the error search(LED p value=0.058, PMV*LED p value=0.083) and correction tasks and the time required(LED p value=0.004, PMV p value=0.000) for their completion were affected by changes in both the PMV thermal environment and the LED light source illumination, whereas a significant difference in visual fatigue was observed only in the PMV thermal environment(p value=0.003).

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.117-124
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• 2002

The lightness of components required in automobile and machinery industry is requiring high strength of components. In particular, manufacturing process and new materials development for solving the fatigue fracture problem attendant upon high strength of suspension of automobile are actively advanced. In this paper, the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in high temperatures($100^{\circ}C,\;150^{\circ}C,\;180^{\circ}C$) was investigated with considering fracture mechanics. So, we can obtain followings. (1) Compressive residual stress is decreased in high temperature, that is, with increasing temperature. (2) The effect of compressive residual stress on fatigue crack growth behavior in high temperature is increased below ${\Delta}K=17{\sim}19MPa\sqrt{m}$. The fatigue crack growth rate is increased with increasing temperature. The fatigue life is decreased with increasing temperature. (3) The dependence of temperature and compressive residual stress on the parameters C and m in Paris' law formed the formulas such as equations (3),(4),(5),(6),(7),(8),(9),(10). (4) It was investigated by SEM that the constraint of compress residual stress for plastic zone of fatigue crack tip was decreased in high temperature as compared with room temperature.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.4
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• pp.426-435
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• 2005

The lightness of components required in automobile and machinery industries is requiring high strength of components. Therefore this requirement is accomplished as the process of shot-peening method that the compressive residual stress is made on the metal surface as one of various improvement methods. Special research is, therefore, needed about compressive residual stress on the metal surface in the process of shot-peening method. Therefore, in this paper the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in environmental condition(temperature) and mechanical condition(shot velocity, stress ratio) was investigated with considering fracture mechanics. By using the methods mentioned above, the following conclusions have been drawn. (1) The fatigue crack growth rate(da/dN) of the shot-peened material was lower than that of the un-peened one. In high temperature range. fatigue crack growth rate decreased with increasing temperature range, while fatigue crack growth rate increased by decreasing temperature in low temperature. (2) Fatigue life shows more improvement in the shot-peened material than in the un-peened material. And compressive residual stress of surface on the shot-peen processed operate resistance force of fatigue crack propagation.

• The Research Journal of the Costume Culture
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• v.29 no.4
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• pp.505-521
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• 2021

This study analyzed the effects of consumer confusion on shopping fatigue and negative purchasing behaviors in an internet shopping environment. Further, the effects of shopping fatigue on negative purchasing behaviors were analyzed. The survey was conducted among consumers in their 20s and 40s in the Seoul metropolitan area who had experience of purchasing fashion products through internet shopping. A total of 392 questionnaire were analysis, with frequency, reliability, factor, correlation, and regression analysis completed using the SPSS statistics program. The results of the study showed that consumer confusion and shopping fatigue in internet shopping environment affected negative purchasing behaviors. First, consumer confusion comprised overload confusion, similarity confusion, and ambiguity confusion. It was found that overload confusion and similarity confusion significantly affected shopping fatigue. Second, shopping fatigue significantly affected negative purchasing behaviors, and an increased level of shopping fatigue result in, increased purchase delay and non-purchase behavior. Third, consumer confusion (overload confusion, similarity confusion, ambiguity confusion) significantly affected purchase delay behavior, while similarity confusion and ambiguity confusion significantly affected non-purchasing behavior. These results will provide useful data for e-CRM and marketing directions of internet companies and will contribute to rational decision-making of internet consumers and improve the quality of consumer life.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1145-1151
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• 2015

High pressure components of a gas turbine engine must operate for a long life under severe conditions in order to maximize the performance and minimize the maintenance cost. Enhanced cooling design, thermal barrier coating techniques, and nickel-base superalloys have been applied for overcoming them and furthermore, material modeling, finite element analysis, statistical techniques, and etc. in design stage have been utilized widely. This article aims to evaluate the effects on the low cycle fatigue life of the high pressure turbine nozzle caused by different turbine inlet temperature profiles and installation conditions and to investigate the most favorable operating condition to the turbine nozzle. To achieve it, the structural analysis, which utilized the results of conjugate heat transfer analysis as loading boundary conditions, was performed and its results were the input for the assessment of low cycle fatigue life at several critical zones.