• Title/Summary/Keyword: stress variables

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The effect of viewing distance and the speed of motion-in-depth on visual fatigue (시각적 피로도에 영향을 미치는 시청거리와 깊이방향의 운동속도)

  • Kham, Kee-Taek;Li, Hyung-Chul;Lee, Seung-Hyun
    • Science of Emotion and Sensibility
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    • v.12 no.2
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    • pp.169-180
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    • 2009
  • The present study have investigated the effect of the characteristics of stereoscopic images and viewing environment on visual fatigue. We manipulated the speed of stereo images with motion-in-depth and viewing distance, which were used as representative variables of the characteristics of stereo image and viewing environment, respectively. Visual fatigue was evaluated with use of a subjective questionnaire which is consisting of 5 different and independent factors: "Eye pain", "Visual stress," "Nauseousness", "Body stiffness", and "Blurriness". In general, when viewing time increased from 10 minutes to 20 and 40 minutes, observers felt severe visual fatigue. Among other factors, only the factor score of "Nauseousness" was significantly increased as the speed of object moving in depth became faster. When viewing distance was increased, the score of "Blurriness" was decreased. These results suggest that different kind of the visual fatigue might be induced depending on characteristics of the stereo images and viewing environment.

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Interactional Effects of Travel Experience and Traumatic Event on Subjective Well-Being (여행경험과 외상적 사건이 주관적 웰빙에 미치는 상호작용)

  • Hong, Sung-Kwon;An, Kyung-Jin;Jang, Ho-Chan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.2
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    • pp.1-10
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    • 2017
  • This study used a quasi-experimental method to investigate if both travel involvement and the degree of recall of a traumatic event affect subjective well-being. For this, independent variables such as positive affect, negative affect, and life satisfaction were established. Four waves of data collection were performed with two to three weeks intervals, then the collected longitudinal data were analysed by repeated measure ANOVA. The study results indicated that travel involvement increases positive affect and life satisfaction, with the effect lasting four weeks or more, which means that travel is an effective tool to boost subjective well-being. Respondents who thought about a traumatic event more frequently had a much higher negative affect following the disaster, and such increased negative affect was maintained over seven weeks or longer. Therefore, this study finds that negative events produce larger, more consistent, or more lasting effects than positive events. As well as travel participation, visiting an urban park is a pleasurable experience. Therefore, the study also finds that urban parks could be utilized for increasing and maintaining subjective well-being in the middle and long term as well as lessening personal stress.

Probabilistic Service Life Analysis of GGBFS Concrete Exposed to Carbonation Cold Joint and Loading Conditions (탄산화에 노출된 GGBFS 콘크리트의 콜드 조인트 및 하중 재하를 고려한 확률론적 내구수명 해석)

  • Kim, Tae-Hoon;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.3
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    • pp.39-46
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    • 2020
  • Carbonation is a deterioration which degrades structural and material performance by permitting CO2 and corrosion of embedded steel. Service life evaluation through deterministic method is conventional, however the researches with probabilistic approach on service life considering loading and cold joint effect on carbonation have been performed very limitedly. In this study, probabilistic service life evaluation was carried out through MCS (Monte Carlo Simulation) which adopted random variables such as cover depth, CO2 diffusion coefficient, exterior CO2 concentration, and internal carbonatable materials. Probabilistic service life was derived by changing mean value and COV (Coefficient of variation) from 100 % to 300 % and 0.1 ~ 0.2, respectively. From the analysis, maximum reduction ratio (47.7%) and minimum reduction ratio (11.4%) of service life were obtained in cover depth and diffusion coefficient, respectively. In the loading conditions of 30~60% for compressive and tensile stress, GGBFS concrete was effective to reduce cold joint effect on carbonation. In the tensile condition, service life decreased linearly regardless of material types. Additionally service life rapidly decreased due to micro crack propagation in the all cases when 60% loading was considered in compressive condition.

Behavior of RC Beam Strengthened with Advanced Lifting Hole Anchorage System (개선된 인양홀을 이용한 정착장치로 보강된 RC 보의 거동)

  • Oh, Min-Ho;Kim, Tae-Wan;Park, Sun-Kyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.3
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    • pp.91-99
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    • 2010
  • In order to strengthen RC structures, various strengthening methods have been used. Particularly, external tendon strengthening method is very popular method to strengthen damaged structures in terms of efficiency, ease, economics. In this study, improved anchorage elements using the lifting hole were proposed to strengthen PSC or RC girder without any damage. Two types of anchorage elements were proposed and these elements were applied on six RC beams. Also, three types of existing anchorage elements were applied on three RC beams. Otherwise, any anchorage element was not applied on one RC beam to used as a control beam. To analyse behavior of these elements, static load tests were carried out. Test variables were anchorage shapes, prestressing level on the steel bar and tendon profiles. Deflections, strains and modes of failure were recorded to examine the strengthening effects of the beams. Ductility index and tendon stress were analyzed by comparing cracking load, yielding load and ultimate load. As a result, proposed anchorage elements using lifting hole were superior to existing anchorage elements in terms of strengthening effect and furthermore, they showed ductile behavior based on energy method.

A Study on the Determinants among Types of the Korean Seniors' Physical Activity and Related Health (국내 노인들의 신체적 활동 유형별 참여와 건강 관련 요인 연구)

  • Chang, Ki-Yeon;Lee, Eun-Jin;Gang, Mi-Yeong
    • The Journal of Korean society of community based occupational therapy
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    • v.10 no.2
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    • pp.47-61
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    • 2020
  • Objective : This study aim to identify the relationships among the types of physical activities included related included related work, sports, leisure, transport and sedentary behaviors and mental health in elderly person. Methods : We analyzed using the data of the 7th Korea National Health and Nutrition Examination Survey(KNHANES VII-1) of 978 subjects who underwent the types of physical activities, quality of life, depression, level of stress, and sleeping hours survey. For statistical analysis, the Complex samples linear regression was used for relationships among the variables. Results : High level of physical activity and house-keeping activity associated negatively on health related quality of life. Mid-High level of leisure activities associated positively on health related quality of life. Contrasting from other studies, which show sedentary activities associated negatively on the health related quality of life, and sedentary activities associated positively on the health related quality of life and mental health. Conclusion : This study shows that physical and leisure activity of an elderly person whilst sedentary activities related positively on health related quality of life, and physical activities related to labor associated negatively on health related quality of life. Future studies should be referred when planning an occupation-focused and meaningful activity program for the elderly people.

The relationship between perceived subjective socioeconomic status and physical health among late school-aged children -A psychosocial perspective- (학령후기 아동이 인지한 주관적 사회경제적 지위와 신체건강과의 관계 -심리사회적 관점-)

  • Kim, Sue-Lynn;Yoo, P. Joan
    • Journal of the Korean Society of Child Welfare
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    • no.57
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    • pp.43-82
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    • 2017
  • As material perspective that stresses absolute income has limitations in explaining socioeconomic gradients in health, research on the relationship between an individual's subjective socioeconomic status(SSS) and health has emerged in recent years. Although previous research has been conducted mostly on adults, late school-aged children, who frequently evaluate themselves using social comparisons, are likely to subjectively perceive their socioeconomic status and be affected by their perception. Accordingly, this study examined the relationship between late school-aged children's SSS and their physical health, and its underlying path based on a psychosocial perspective. For this purpose, data from the first year survey of the Seoul Education and Health Welfare Panel (2014), which consisted of responses from 394 children ($4^{th}$ graders in elementary school) and their parents, were analyzed utilizing structural equation modeling. The results showed an indirect but significant relationship between late school-aged children's SSS and their physical health, via stress, self-efficacy, and health behaviors, which are mediating variables grounded on a psychosocial perspective. No direct relationship was found between late school-aged children's SSS and physical health. Based on these findings, we suggested several implications to improving children's health, including efforts to prevent adverse effects of low SSS on physical health through psychosocial factors.

Effect of Blood Donation on the Donor's Hemorheological Properties (헌혈이 헌혈자의 혈유변학적 지표에 미치는 영향)

  • Lee, Byoung Kwon
    • The Korean Journal of Blood Transfusion
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    • v.29 no.3
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    • pp.229-239
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    • 2018
  • The circulatory system is closely related to the inter-relationship between the anatomy of the heart and blood vessels, and the fluid dynamic properties of blood. The physical properties of blood, which affect blood flow, are called hemorheologic factors. Hemorheologic factors, such as blood viscosity and erythrocyte aggregation, are influenced mainly by hematocrit. A higher hematocrit level results in an increase in blood viscosity, erythrocyte aggregation, which impedes the circulation itself, and tissue oxygenation. An excess of serum ferritin causes injury to vascular endothelial cells and erythrocytes via oxygen free radicals. In addition, an excess of blood can aggravatee the adverse effects of the hemorheologic parameters and induce atherogenesis, microcirculatory disturbances, and major cardiovascular events. A preventive and therapeutic approach with a phlebotomy or blood donation has been stimulated by the knowledge that blood loss, such as regular donations, is associated with significant decreases in key hemorheologic variables, including blood viscosity, erythrocyte aggregation, hematocrit, and fibrinogen. Major cardiovascular events have been improved in regular blood donors by improving blood flow and microcirculation by decreasing the level of oxidative stress, improving the hemorheologic parameters, and reducing the serum ferritin level. Confirmation of the positive preventive and therapeutic effects of blood donations on cardiovascular disease by a well-designed and well-controlled Cohort study may be good news to patients with cardiovascular disease or at risk of these diseases, as well as patients who require a transfusion.

The Influence of the Organization and Implementation of the Curriculum on Teachers' Characteristics and Schools' Peculiarities in Specialized Industry High Schools (교사 및 학교별 특성이 특성화 공업계 고등학교의 교육과정 편성 및 운영에 미치는 영향)

  • Park, Changun;Shin, Seung-Keol;Oh, Kyunghee;Kim, suyeun
    • Journal of vocational education research
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    • v.29 no.3
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    • pp.41-60
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    • 2010
  • The purpose of this study was to investigate the relationships between teachers' characteristics and schools' peculiarities and to analyze relevant variables which influence the organization and implementation of the curriculum in specialized industry high schools. Subject were 414 teachers in specialized industry high school. The main result of this study are as follows. First, according to teachers' sex distinction, position, teaching experience, career of industry-related companies, subtle stress difference were found in establishment of education programs, relevance of educational activity, propriety of equipment. Second, in case of schools' subject of establishment, dormitory, specialized types, number of class, type of the sex of recruitment, subtle difference were found in connectivity of graders and subjects, relevance of the organization of education activity, substantial curriculum, push ahead with specialized high school. Third, measures to support development of specialized curriculum arrange sub-items in order of frequency. The way we understand things on vocational education must be settled without delay.

Difference in lifestyle according to whether breast disease occurs (여성의 유방질환 발생여부에 따른 생활습관의 차이에 대한 융합연구)

  • Lee, Ok Suk;Choi, So Young
    • Journal of the Korea Convergence Society
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    • v.10 no.2
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    • pp.57-66
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    • 2019
  • The purpose of this study was to identify the risk factors of breast disease by checking the difference in lifestyle and the natural estrogen-containing food intake. The subjects were women who visited the J-City Women's Hospital between the ages of 20 and 60 (disease=85, non disease=93) and to avoid the demographic factors that might affect lifestyle, and to ensure the homogeneity of the two groups, (${\pm}5$ years old) were randomly expressed. The logistic regression analysis was performed to examine the influence of variables on breast disease. The probability of receiving a diagnosis of breast disease increased by 3.04 times, the probability of receiving a diagnosis of breast disease was 4.76 times higher than that of others such as brown rice grains, and the hobby life of stress relieving methods The probability of being classified as breast disease was 2.38 times. People who have experience of artificial abortion, those who enjoy white rice, and those who do not enjoy hobbies are more likely to be diagnosed with breast disease. The breast disease prevention and education program and the education program for the general public reflecting this characteristic will be necessary.

Convergent Factors Affecting Depression of Drinkers by Age (연령에 따른 음주자 우울의 융합적 영향요인)

  • Kwon, Myoungjin;Kim, Jihyun;Jeong, Sunkyung
    • Journal of the Korea Convergence Society
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    • v.10 no.3
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    • pp.383-393
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    • 2019
  • The present study was conducted to determine convergent factors affecting depression in drinker by age. This was a cross-sectional secondary data analysis study that used the raw data from the Korea National Health and Nutrition Examination Survey in 2014 & 2016. The subjects of the present study were 4,446 middle-aged drinker. Variables related to general characteristics, physical and psychological factors were selected. After a sampling plan compound file was created using IBM SPSS 23.0 program, data were analyzed by giving weights. Depression was influenced by gender (30s, 50-60s), income (30-40s, 60s), education (30-40s), number of family members (30-60s), job (30-60s), eating level (30-40s, 60s), hypertension (40s), DM (30-40s), BMI (30-40s), smoking (30s, 50s), exercise (30s), weight control (60s), drinking binge (30-60s), subjective health (30-60s), subjective body awareness (30-50s), stress (30s-60s), quality of life (30-60s). It is required to design preventive interventions and management plans for depression, considering these factors comprehensively.