• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.653-662
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• 2011

As technology in 3D industry has rapidly advanced, a lot of studies primarily focusing on visual function and cognition have become vigorous. However, studies on effect of 3D visual fatigue on autonomic nervous system have not less been conducted. Thus, this study was to identify and determine the effect that might have a negative influence on sympathetic nervous system, parasympathetic nervous system, and cardiovascular system. Fifteen undergraduates (female: 9, mean age: $22.53{\pm}2.55$) participated and were sat on a comfortable chair, viewing a 3D content during about 1 hour. Cardiac responses like SDNN(standard deviation of RR intervals), RMS-SD(root mean squared successive difference), and HF/LF ratios extracted from the measured PPG(Photo-PlethysmoGram) before viewing 3D were compared to those after viewing 3D. The results showed that after subjects watched the 3D, responses in sympathetic nervous system and parasympathetic nervous system were activated and deactivated, respectively relative to those before watching the 3D. The results showed that HF/LF ratio, Ln(LF), and Ln(HF) after viewing 3D were significantly reduced relative to those before viewing 3D. No significant effects were observed in SDNN and RMS-SD. Results obtained in this study showed that visual fatigue induced by watching 3D adversely influenced autonomic nervous system, and thereby reduced heart rate variability causing sympathetic nervous acceleration.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2012.05a
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• pp.9-10
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• 2012

• Journal of People, Plants, and Environment
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• v.22 no.3
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• pp.309-319
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• 2019

This study was conducted to investigate the effects of watching a virtual reality (VR) forest video on stress reduction in adults. Experiments were performed in an artificial climate chamber where temperature, humidity and illumination were controlled. To cause stress in subjects, the subjects were asked to multiply two digit numbers by one digit numbers for two minutes. The subjects then watched a VR forest video for five minutes. During the experiment, the heart rate variability (HRV) and heart rate (HR) of subjects were continuously measured for evaluating their physiological state. After measuring the baseline and watching a VR forest video, their psychological state was evaluated using the profile of mood state (POMS), semantic differential (SD) method, and positive affect and negative affect schedule (PANAS). The results of physiological evaluation after watching a VR forest video showed a decrease in the stress index and HR, an increase in the activity of the parasympathetic nervous system, and the standard deviation of normal to normal RR intervals (SDNN). The results of psychological assessment confirmed that watching a VR forest video induced "comfort", "natural", and "soothed" feelings in subjects. In addition, watching a VR forest video decreased "tension-anxiety (T-A)", "depression-dejection (D)", "anger-hostility (A-H)", "fatigue (F)", "total mood disturbance (TMD)", and increased "vigor (V)" compared to the base line, and decreased "negative affect" and increased "positive affect." These results indicate that watching a VR forest video decreases adults' stress index, stabilizes physiological state, and has a positive impact on psychological state. The findings of this study can serve as a basis for providing forest welfare services to people in the blind spots of forest welfare, and can lay a foundation for the adoption of VR, one of the technologies of the fourth industrial revolution in forestry.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.105-109
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• 2014

Purpose: To compare the change of visual acuity and NIBUT after watching smart-phone in 1 hour under low intensity of illumination. Methods: 50 subjects (male 22, female 28) aged 20's years old ($20.7{\pm}2.4$ years) who do not have eye disease and have a good eye condition were participated for this study. Objective refraction, corrected distance visual acuity and NIBUT were measured before and after watching smart-phone (Galaxy 2, Samsung, KOREA) under low intensity of illumination (0 lx.) Objective refraction was carried out using auto-chart project (CP-1000, Dongyang, Korea), phoropter (VT-20, Dongyang, Korea) and auto refractor-keratometer (MRK-3100, Huvitz, Korea). Results: Refractive error was changed from $-3.20{\pm}2.00$ D to $-3.38{\pm}2.00$ D (p=0.006) and corrected distance visual acuity was changed from $0.93{\pm}0.08$ to $0.91{\pm}0.10$ (p=0.000) and NIBUT was changed from $10.48{\pm}7.00$ seconds to $10.29{\pm}6.47$ seconds (p=0.761) before and after watching smart-phone under low intensity of illumination. Conclusions: Continuous watching smart-phone under low intensity of illumination lead to temporal change of distance visual acuity and suitable rest may reduce the influence of distance visual acuity and tear safety.

• The Journal of the Korea Contents Association
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• v.17 no.2
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• pp.521-534
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• 2017

In 2013 the Netflix, an OTT in USA, launched all at once 13 episodes of the House of Cards season. Binge-watching is the word which means watching continuously 2~6 episodes of a TV program with one sitting, the new normal of TV watching behavior, cultural and social currents all over the world. This study has analyzed the factors and motivations which affect to the persistent intention to use binge-watching. It conducted an online survey from 333 Quota sample from Korean age groups between 20th~60th with 81 questionnaires. The 5 groups were induced as motivation factors to binge-watching. The 3 groups which consisted of , , are affecting as positive to intention to use binge-watching. But the other 2 groups which are and doing as negative. The survey has shown that the persistent intention to binge-watching is affected by ages more younger, whom doing binge watching more frequently, whom estimating more higher to the conceived usefulness to use. As a theoretical model, expanded technology acceptance model was adopted and US drama House of Cards. This study could promote the next generation contents planning and S-VOD service industry.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.11
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• pp.990-999
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• 2013

Previous studies based on the theoretical evidence and based on the empirical data have been constantly revealing related factors affecting visual fatigue in viewing 3D images. however, the measurement data coupled with the factors that affect the viewers to feel fatigue is insufficient. this study research that the viewers feel the visual functional data is based on subjective fatigue such as IPD, AC/A ratio, and the degree of phoria and the effects on variance in these data, is to examine the correlation between these data. based on the average score of subjective fatigue which is $6.00{\pm}3.88$, total fatigue points from 0 up to 6 is classified as a group not appealing for the fatigue and from 7 up to 16, they were classified as the fatigue appealing group. the results showed no difference in satisfaction of the images by each subjective fatigue, IPD and far phoria. AC/A ratio was higher from the fatigue not appealing group, near phoria was higher from the fatigue appealing group. after watching 3D images, the fatigue not appealing group showed a tendency of higher increase of exophoria. correlations appeared in this experiment showed that AC/A ratio and near phoria are closely related to level of subjective fatigue which feel when watching 3D images. when watching 3D images based on two data appear to be able to predict the fatigue, even during content production fatigue reduce the data dimensions to be used as the main basis is expected.

• Korean Journal of Community Nutrition
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• v.7 no.2
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• pp.177-187
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• 2002

This study was done to determine the factors associated with childhood overweight in 721 sixth grade elementary school students, in Busan. The students' heights, weights, waist circumferences and triceps-skinfold thicknesses were measured using standard techniques. Other data were collected using a questionnaire that included information about physical activity, television watching, and the amount of exorcise taken during leisure times, family history of diseases related to obesity: social data including family income, parents'education and occupations, eating behaviors; parental weights and heights; and parental activity levels. Childhood overweight was defined as a body mass index at or above the 85th percentile for age and sex. The prevalence of overweight revealed no significant difference between sexes, (24.2% in boys and 22.03% in girls). The risk of childhood overweight was significantly greater if either the mother or the father were overweight. The odds ratio for childhood overweight associated with maternal overweight was 5.045 (94% CI : 3.262-7.801), and 2.727 (95% CI : 1.764-4.218) was the case for parental overweight. Children having a history of hear diseases had higher odds ratios than those who did not. The odds ratios for overweight associated with income were not different. However, a higher odds ratio for overweight was observed in children whose fathers had only an elementary or middle school education than those whore fathers had a high school or college education. Children whose fathers' occupations were service workers or shopkeepers (OR : 3.314, 95% C = 1.851-5.934) or had no occupation (OR = 3.756, 95% CI : 1.898-7.430) had a treater risk of overweight than those whose fathers'were professionals or once workers. The risk of overweight increased in children having more irregular meal times and faster eating times, rather than those having an intake pattern of high energy and sugar containing floods. The amount of exercise taken during leisure times, and daily physical activity showed no difference between overweight and non-overweight children. However, television watching time, especially on weekends, was greater in overweight children than in non-overweight children. Television watching time was positively correlated with BMI, triceps-skin(31d thickness, waist circumference and waist/height ratio. Therefore, television watching was found to be a useful predictor of overweight in children. Television watching in children was negatively related to paternal activity levels, and positively related to parental television watching time. In fact, fathers whose children were overweight were physically less active than fathers whose children were non-overweight. Parents appeared to be a strong influence on their children's physical activity levels. In conclusion, a low family social class, defined on the basis of the father's occupation or education, parental overweight, increased television watching, and unhealthy physical activity levels in parents were all considered risk factors for childhood overweight. Among these, television watching time and lack of physical activity were considered to be the most important risk factors that could be easily modified for the prevention of and intervention in, overweight in children.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1811-1814
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• 2007

Accommodation error is one of the main factors that degrade the comfort while watching stereoscopic 3D images. We analyze the limit of the expressible 3D depth without an accommodation error using the human factor information and wave optical calculation under Fresnel approximation.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.440-453
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• 2019

This study was carried out to investigate the effect of watching a two-dimensional (2D) forest video and a virtual reality (VR) forest video on stress reduction in adults. Experiments were conducted in an artificial climate room, and 40 subjects participated. After inducing stress in the subjects, subjects watched a 2D gray video, 2D forest video, or VR forest video for 5 mins. The autonomic nervous system activity was evaluated continuously in terms of measured heart rate variability during the experiment. After each experiment, the subject's psychological state was evaluated using a questionnaire. The 2D forest video decreased the viewer's stress index, increased HF, and reduced heart rate compared with the 2D gray video. The VR forest video had a greater stress index reduction effect, LF/HF increase effect, and heart rate reduction effect than the 2D gray video. Psychological measurements showed that subjects felt more comfortable, natural, and calm when watching the 2D gray video, 2D forest video or VR forest video. We also found that the 2D forest video and VR forest video increased positive emotions and reduced negative emotions compared to the 2D gray video. Based on these results, it can be concluded that watching the 2D forest and VR forest videos reduces the stress index and heart rate compared with watching the 2D gray video. Thus, it is considered that the 2D forest video increases the activity of the parasympathetic nervous system, and the VR forest video increases the activity of the sympathetic nervous system. The increased activity of the sympathetic nervous system upon watching the VR forest video is judged to be positive sympathetic nerve activity, such as novelty and curiosity, and not negative sympathetic activity, such as stress and tension. The results of this study are expected to be the basis for examining the visual effects of forest healing, with hope that the utilization of VR, the technology of the fourth industrial revolution in the forestry field, will broaden.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.941-948
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• 2021

This study investigated the differences between active and inactive TV watching groups, in terms of residential characteristics, of class-oriented drama viewing rate. We compared Flow and Social Comparison Theories to explain the relationship between class-oriented contents in the drama and viewing rate. We collected 110,000 TV viewers data of 4 class-oriented and the other 4 dramas, aired between Feb. 2016 and March 2019, through D-Live local cable service provider. Controlling gender ratio and income level which may affect viewing rate, we found that class-oriented content significantly and positively affects viewing rate in active watching group while the same content significantly and negatively affects viewing rate in inactive watching group. These results imply that Flow and Social Comparison Theories may apply in opposite directions in different watching groups.