• Korean Journal of Child Studies
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• v.15 no.2
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• pp.55-68
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• 1994

A survey analysis of home video games was carried out for 1,018 elementary school children. Children responded to a questionnaire consisting of sociodemographic variables, degree of game participation(frequency and mean time), control behavior(eg. resting during games, lightening interior), and physical symptoms(eg. eyestrain, headache, trembling, paralyses) during and/or after playing games. Statistical analysis was done by frequency, percentile, and chitest. The results showed that many children enjoyed video games frequently and played continually, that few children did control behavior during games. Main variables related to degree of game playing and control behavior were sex, game experience, parent's education, and mother's activity. In particular, the results implied that the level of physical symptoms during and/or after game differed by lighting factors.

• Journal of the Korean Professional Engineers Association
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• v.43 no.3
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• pp.23-27
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• 2010

Since 3DTV was introduced, the market could not grow further due to the several causes such as the lack of content, technology for production and display and eyestrain. However, the rapid advances of the technologies on digital broadcasting, consumer electronics and computer enabled the commercialization of 3D animation, computer graphic, 3D advertising as well as 3D movies, and since then the international technical competition is growing fiercer. Since much more companies introduced the solutions for 3D in NAB 2010 than 2009, the expected size of the market will be bigger than ever before. This article describes the recent trends and the prospect of the 3D technologies including national defence strategy, content, construction, consumer electronics, advertisement, and terrestrial 3D1V pilot project in Korea.

• Korean Journal of Occupational Health Nursing
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• v.31 no.2
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• pp.95-103
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• 2022

Purpose: This study aims to identify general, workplace, and health-related characteristics of outdoor workers exposed to high temperatures, and to compare the risk of disease according to outdoor high temperature exposure. Methods: This secondary analysis study used the 5th Korean Working Conditions Survey (2017) to identify 4,915 outdoor workers exposed to high temperatures. Results: Outdoor workers exposed to high temperatures were mostly male, elderly, less educated, and daily contract workers. Most of them were engaged in agriculture, forestry and fishing, and construction industries. About 40~50% of them complained of musculoskeletal pain and overall fatigue. The results showed that high temperature exposure increased the risk of illness (hearing problem, skin problem, backache, muscular pains in upper and lower limbs, headache/eyestrain, injuries, depression, and overall fatigue) among workers. Conclusion: High temperature exposure might increase the risk of illness among workers. The results of this study demonstrated that the outdoor workers should be protected from high temperatures.

• Journal of the Korean Society of Safety
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• v.38 no.6
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• pp.16-25
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• 2023

This study investigated health problems and work-relatedness for fishermen. In total, 121 fishermen (103 males and 18 females) were extracted from the data of the 6th Korean Working Conditions Survey. Two groups (Symptomatic and Asymptomatic) were statistically compared in terms of health problems and exposure to hazards. The most common health problems identified for fishermen were muscular pain in the shoulder, neck, and upper limbs (73.6%), backache (71.1%), muscular pain in the lower limbs (58.7%), overall fatigue (33.9%), headaches or eyestrain (22.3%), and anxiety (8.3%). These health problems were found to be related to the working conditions of the fishermen (low temperatures, tiring or painful postures, stance, sitting position, repetitive hand or arm placement, and the experience of stress). This study's findings may help us better understand the characteristics of the health problems and work-relatedness of fishermen and could be helpful for improving fishermen's overall health and safety.

• Journal of Pharmacopuncture
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• v.13 no.4
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• pp.91-107
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• 2010

Objectives : The purpose of this study was to analyze the propensity and find out the Syndrome Differentiation of teeth-mark tongue by taking survey and body examinations with 178 male patients. 164 patients out of 178 were checked up on Heart Rate Variability (HRV), Accelerated Photoplethysmograpy (APG), Body Composition. This study was also planned to find out the distinctive characteristics of teeth-mark tongue diagnosis and compare differences between Qi-Deficiency and Accumulation of Dampness and Phlegm patients group. Methods : The questionnaire was carried out targeting 178 male with teeth-mark tongue respondents among who had Oriental Health Examination and patients from the 3rd oriental-internal medicine department in Dongeui Hospital from $1^{st}$, March 2005 to $30^{th}$, April 2010. Only 164 patients were checked on HRV, APG and Body composition examinations. Results : It showed that 86 patients had Qi-Deficiency and 78 had Dampness and Phlegm but 14 couldn't be categorized. The major symptoms of Qi-Deficiency compared to Dampness and Phlegm were 'Frequent running nose', 'Soft stool', 'Chronic fatigue', and 'Eyestrain'. On the contrary, Dampness and Phlegm's dominant symptoms were 'Chest discomfort', 'Feeling bloated', 'Back pain', 'Feeling sluggish', and 'Itchy skin'. However, all symptoms were not matched with the Syndrome Differentiation of Qi-Deficiency or Dampness and Phlegm. It also showed that teeth-mark tongue patients' frequent symptoms were 'Stuffy nose', 'Feeling bloated', 'Oliguria', 'Shoulder pain', 'Chronic fatigue' 'Eyestrain' and these symptoms were matched with the Syndrome Differentiation of Qi-Deficiency and Dampness and Phlegm. In the results from this study, there were no significant differences between Qi-Deficiency and Dampness and Phlegm. Conclusions : It is hard to conclude that teeth-mark tongue could be only one to diagnose Qi-Deficiency or Dampness and Phlegm with 3 examinations.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.4
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• pp.550-561
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• 2019

Objectives: The purpose of this study is to provide basic data for the improvement of the working environment for health prevention and related countermeasures for shift workers. This study was conducted based on the Fifth Korean Working Conditions Survey (KWCS), which analyzed the health effects of shift work forces and compared them with preceding studies. Methods: By analyzing secondary rates using raw data from the 5th KWCS, 4,870 (9.7%) of the 50,184 total study subjects were divided into shift work and 45,314 (90.3%) non-shift work groups based on the response to shift status. Variables that could affect work health issues were identified and corrected. A cross-analysis was conducted to examine demographic characteristics (gender, age, and education level) of the workers and occupation characteristics (monthly net earnings, employment type, occupation, working period up to now, workplace scale, type of work system, and weekly working hours). In order to find the work health issue ratio between the shift and non-shift work groups, logistic regression was analyzed and the association with health problems according to shift type by gender was looked at through cross-analysis. Results: According to the surveys conducted from the 1st KWCS (2006) to the 5th KWCS (2017), the proportion of shift workers continued to increase. Also, muscular pains in the lower limbs (hips, legs, knees, feet, etc.) (OR=1.135, 95%CI 1.031-1.251), headaches, eyestrain (OR=1.580, 95% CI 1.428-1.748), anxiety (OR=1.715, 95% CI 1.402-2.099), difficulty falling asleep (OR=1.391), and other problems (OR=7.392) were reported. In addition, back pain, muscular pains in shoulders, neck and/or upper limbs, muscular pains in lower limbs (hips, legs, knees, feet, etc.), headaches, eyestrain, depression, anxiety, overall fatigue resulted in significant results for both male and female shift workers. Depression and anxiety were higher in female shift/circulation compared to males. Conclusions: The social nets for the health and safety of shift workers should be explored in a variety of ways, including management and supervision of shift sites, attempts to reorganize and improve the shift system, development of workers' health recovery programs, promotion, systematic treatment, and compensation systems.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.421-425
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• 2007

A new 3D rear projection display system using double-layer polarization-selective screen systems, one stacked in front of the other, has been developed. The front and rear screens are made of scattering polarizer films, and they either diffuse-scatter or transmit the incident light depending on the polarization state of the light. The near and for images are projected onto the front and rear screens, respectively, using light waves with mutually orthogonal polarization states. The new display system produces clear high-resolution images, which are visible over a wide range of viewing angle. It was found that the impression of depth is pronounced and eyestrain is only comparable to that by 2D display systems.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.37-41
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• 2008

Purpose: The purpose of this case study is to prescribe a prismatic correction in uncommon case of cyclovertical heterophoria. Methods: The prescribed prism was used to balance the vertical vergence break values by the binocular vision evaluation such as phoria, vergence, accommodative function and the others. Results: Although asymptomatic lateral phoria was changed, the vertical prismatic correction improved the symptoms such as eyestrain, headaches, diplopia and others. And cyclophoria was disappeared by prismatic correction. Conclusions: The prismatic correction for this case was useful for alleviating symptoms of cyclovertical deviations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3416-3422
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• 2014

A shock absorber rod is located in the center of the absorber piston and is responsible for the reciprocating movement portion. If it has surface defects, the damping performance of product will be adversely affected. A rod surface has gloss by heat treatment. Therefore, it is difficult to find a defect, such as dust, imprints, and blowholes. Because a total inspection is achieved by visual inspection by workers, it causes eyestrain and the quality of the product is not constant. In this paper, a machine vision system was developed to find a defect using a line-scan camera. The machine can detect surface defects than 0.3mm. To minimize the occurrence probability of defects on the inspection process, the developed auto inspection system had an automatic feeding system and incorporated a protection system. Through the development of this system, which relies on the operator's visual inspection of the surface of the shock absorber, the Rod inspection system constructed quality inspection standards and standardized tests to ensure improved reliability.

• YAKHAK HOEJI
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• v.59 no.3
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• pp.107-112
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• 2015

Blueberries (Ericaceae) are cultivated worldwide, and are used not only as foodstuff but also for relievement of eyestrain. Bluberry species representatively includes highbush blueberry (V. corymbosum L.), lowbush blueberry (V. angustifolium $A_{IT}$.), rabbiteye blueberry (V. ashei $R_{EADE}$), and bilberry blueberry (V. myrtillus L.). All of these species contain large amounts of phenolics and anthocyanins. In this regard, we isolated six compounds from Korea cultivated blueberry and identified as 3-O-caffeoylquinic acid (1), 5-O-caffeoylquinic acid (2), myricetin-3-O-${\beta}$-D-galactoside (3), quercetin-3-O-rutinoside (4), ethyl-3-O-caffeoylquinic acid ester (5), ethyl-5-O-caffeoyl quinic acid ester (6) by $^1H$-NMR, $^{13}C$-NMR and MS. Anti-oxidative activities of six compounds were verified by anti-oxidant assay such as DPPH, ABTS and Hypoxanthine/xanthine oxidase system. And then, anti-oxidant activities of Korea blueberry and Canadian were compared with each other. These results support that Korean blueberry has also the possibility to be potential supplementary material as healthy food like Canadian blueberry. Therefore, Korean blueberry can be used as a substitute of Canadian blueberry.