• Journal of Korean Institute of Industrial Engineers
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• v.16 no.1
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• pp.67-81
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• 1990

Effectiveness of physical exercise in reducing work-related musculoskeletal stress was investigated. This was compared to the stress alleviation accomplished by using ergonomically designed work station. Tasks chosen for the study were data entry and file maintenance on the video display terminal (VDT). Three different measures, namely root-mean-square (RMS) values of electromyogram (EMG), subjective rating and task performance were used for the evaluation. Electromyograms were recorded from the neck, the left and right trapezius muscles in the shoulder region, and L2/L3 region of the back. Subjects rated discomfort levels for the same parts of their body. Task performance was measured by recording typing speed and errors. Each of the five subjects was tested for two days (8 hours/day) in two different work stations. These were the ergonomically designed adjustable work station and the fixed work station of traditional design with no adjustable features. Assigned physical exercises were performed for four minutes, every two hours during the breaks, by the subjects while working in the fixed work station. It was concluded that the physical exercise could be helpful in reducing musculoskeletal stress as effectively as the ergonomic design of the VDT work station.

• Journal of Preventive Medicine and Public Health
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• v.38 no.1
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• pp.45-52
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• 2005

Objectives : To investigate the fatigue subjective symptoms and VDT related risk factors in bank workers. Methods : A total of 2178 workers (62.8% male, 37.2% female) were surveyed with a self-administered and structured questionnaire consisting of 30 fatigue symptoms and other VDT related factors regarding work characteristics, work postures, work environments, personal medical histories, etc. Fatigue subjective symptoms were divided into 3 groups of 10 questions each: a dull, drowsy and exhausted feeling (Group I), a mental decline of working motivation (Group II), or a feeling of incongruity in the body and dysfunction of autonomic nervous system (Group III). Each question was weighted as 0 for 'none', 1 for 'sometimes', and 2 for 'always'. Results : Mean age was $35.8{\pm}7.2$ years ($38.9{\pm}6.0$ in males, $30.6{\pm}5.8$ in females), Mean work duration was $7.7{\pm}7.1$ years ($8.4{\pm}7.4$ in males, $6.5{\pm}6.4$ in females). Mean symptom score in males was $11.0{\pm}8.1$ ($4.9{\pm}3.1$ in Group I, $3.0{\pm}3.1$ in Group II, $3.1{\pm}2.8$ in Group III) and in females was $17.5{\pm}9.5$ ($7.0{\pm}3.8$ in Group I, $4.6{\pm}3.5$ in Group II, $5.9{\pm}3.4$ in Group III). Mean scores were higher in the order of Group I>III>II. Females had significantly higher scores than males in all three groups (p<0.001). Most common symptoms complained of as 'always' or 'sometimes' were feel strained in the eyes' (85.4%) among Group I, 'find difficulty in thinking'(54.2%) among Group II, and 'feel stiff in the shoulders (72.3%) among Group III. In multiple regression analysis, female, non-straight spine at workstation, more VDT work hours, history of physical therapy, glare of screen, overtime work, young age, and non-horizontal elbow position were significantly related with high score of symptoms. Conclusions : More supportive VDT work environment and education for correct work postures for VDT workers are recommended.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.18-26
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• 2018

This study aimed to examine whether there was difference on visual fatigue between active seniors and young people, and to provide a guideline for appropriate computer use time for seniors. Blinking rate, maximal blinking interval, temperature of the ocular surface, visual fatigue questionnare were evaluated. The blinking rate, ocular surface temperature, visual fatigue showed significant change before and after the tasks. There was no difference between the two groups and thus, about 30-minute computer work appeared to be appropriate for seniors.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.75-86
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• 1998

The purpose of this study is to evaluate the effects of continuing work on VDT(video display terminal), therefore this study examined visual fatigue, unaided visual acuity, refractive error, accommodation and horizontal phoria of 152 subjects who did two hour long VDT work. For the ocular symptoms, the greatest number was tired eyes accounting for 45.71%. In the visual symptoms, blurred vision was the hightest rate of 80.39% and in case of systemic symptoms shoulder pain was 33.33% marked top ranking. The average of near visual acuity decresed almost 10% from 0.47 to 0.42, but refractive error increased about 0.10D to the direction of myopic shift. The amplitude of accommodation decreased approximately 0.72D from 7.46D to 6.74D. Accommodation facility was delayed from 2.27 second to 2.50 second, the amplitude of positive relative accommodation was decreased from 4.76D to 4.16D and the amplitude of negative relative accommodation was decreased from 2.46D to 2.33D. The horizontal phoria shifted to the direction of esophoria from $1.82{\Delta}$ to $3.24{\Delta}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.264-273
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• 2012

This cross-sectional study was investigated musculoskeletal discomfort symptoms and related factors on some middle high school teachers. Self-questionnaire of KOSHA CODE H-30-2003 was done with 250 teachers from 1st to 15th October, 2010, the data from 231 teachers (68 male, 163 female) was statistically analyzed to search the factors related to musculoskeletal discomfort symptoms. According to NIOSH rate of musculoskeletal discomfort symptoms by body parts was 36.8%. Musculoskeletal discomfort symptoms related to age, school types, subjective health status, housekeeping time, VDT work time and regular rest. After adjusting for related variables, odds ratio (OR) of musculoskeletal discomfort symptoms was correlation significantly to subjective health status unhealthy (OR 11.75, 95% Confidence Interval, CI, 3.56-378.78). In addition, ORs (95% CI) of age (40-49) and housekeeping time (${\geq}3$) were 4.63 (1.82-26.18) and 4.33 (1.97-19.34). Analysis of the factors influencing the musculoskeletal discomfort symptoms vary in different parts of the body. The most discomfort symptoms by parts was neck (26.0%) and shoulder (30.0%). In the neck region was related to subjective health status and regular rest. In the shoulder and waist region was subjective health status and sex. Age was wrist/finger, leg/foot was related to subjective health status, sex and VDT work time. Age, school types, subjective health status, housekeeping time, VDT work time and regular rest related to musculoskeletal discomfort symptoms and the most discomfort symptoms by parts was neck and shoulder.

• JOURNAL OF ELECTRICAL WORLD
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• no.5 s.197
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• pp.38-45
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• 1993

하루가 새롭게 변천되어 가는 현대사회라고 하지만 컴퓨터기술만큼 빠르게 변화하는 것도 없을 것이다. 하루가 멀다하고 새기술, 새제품이 쏟아져 나오는데 이것은 제품을 뒷받침하고 있는 컴퓨터 기술의 발전에 힘입은 것이라고 해도 과언이 아니다. 따라서 정보화 시대를 살아가는 현대인들은 각자 맡은 바 분야의 수준에 따라 컴퓨터에 관련된 제반지식을 익히는 것이 필요하다고 생각된다. 본란은 이러한 취지에 입각하여 컴퓨터의 Software, Hardware 및 관련용어들을 알기 쉽게 풀이한 것이다.

• Physical Therapy Korea
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• v.15 no.2
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• pp.73-80
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• 2008

With the introduction of the video display terminal (VDT), the efficiency and productivity of work has improved. However, VDT syndrome is threatening the health of workers as a side effect of prolonged use of a VDT. Among various VDT syndromes, the musculoskeletal disorder, especially, the cumulative trauma disorder (CTD) is the common research topic related with upper extremities function. The aim of this study was to investigate the effect of the wrist-hand orthosis (WHO) on fatigue in middle deltoid, anterior deltoid, serratus anterior, and upper trapezius during one-hour computer keyboard typing. Twelve healthy subjects participated in this study. Surface electromyography was used to assess the localized muscle fatigue (LMF), and the LMF was calculated at 10 minutes, 20 minutes, 40 minutes, and 60 minutes in each muscle, with and without the WHO. Data were analyzed by paired t-test with a level of significance of .05. The results of this study are as follows: 1) At 10 minutes, the LMF decreased significantly with applied WHO in the middle deltoid, anterior deltoid, and upper trapezius (p=.001, p=.026, p=.019, respectively). 2) As the computer keyboard typing period increased, there were no significant LMF differences, except for the upper trapezius. Therefore, it can be concluded that the WHO can be applied to decrease the LMF for the initial 10 minute period in the middle deltoid, anterior deltoid, and upper trapezius' but that the long term effect of WHO in reducing the LMF was proven only in upper trapezius during continued computer keyboard typing.

• PNF and Movement
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• v.15 no.2
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• pp.149-157
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• 2017

Purpose: The purpose of this study was to assess the effect of using smartphones for tele-rehabilitation on head position and neck dysfunction in workers with visual display terminal (VDT) syndromes over a four-week period. Methods: Sixteen VDT workers volunteered to participate in stretch exercise and posture education sessions. The subjects were divided into three groups as follows: five subjects in the visit group (VSG), six subjects in the video group (VEG), and five subjects in tele-rehabilitation group (TG). The subjects in all the groups performed the exercises three days per week for four weeks. Cranial rotation angle (CRA), craniovertebral angle (CVA) measurement, and neck disability index (NDI) tests were performed before and four weeks after the intervention. Results: No significant difference in the CRA and CVA variables was found among groups. No significant difference in the CRA variable was found within each group. A significant difference in the CRA variable was found in the VSG after the four-week intervention. No significant difference in NDI was found among the groups. The NDIs among all the groups were significantly decreased after the intervention when compared with the NDIs measured before the intervention. Conclusion: The use of smartphones in the tele-rehabilitation of VDT workers with neck pain was found to be as effective on neck function as the conventional intervention method. The tele-rehabilitation of VDT workers with neck dysfunctions may be presented as an alternative way.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.42
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• pp.39-47
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• 1997

There are four parameters (i.e. overall density, local density, grouping, layout complexity) to consider in designing screen of a visual display terminal. Among these, only the optimum level of overall density is known to be about 25~30% by some studies. Therefore, the present experiment is conducted to define the optimum levels of the other parameters to achieve the user's best performance in visual search task. The results are as follows; (1) The function related to the levels of local density and user's search times is shown to be U -shaped. When the level of local density is about 40%, the search time is shorter than those of any other levels. (2) In the experiment of grouping, user's performance is best when the number of group is 5, and the size of group does not exceed visual angle $5^{\circ}$ (0,088rad). (3) The user performance is improved as the layout becomes less complex.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.128-135
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• 1997

우리 나라에서 발생하는 누적외상성질환 실태에 대한 조사,연구는 그리 많지 않은 편으로서, 이미 보 고된 연구 결과나 직업병으로 인정된 사례들은 대부분 사무직종에 근무하는 VDT 작업자들이다. 특히 제조업의 경우, 이 질환을 유발시킬 수 있는 업종과 공정이 매우 다양하고 작업자수 또한 전체산업인 구 (10인 이상 상용근로자 기준)에서 차지하는 비율이 '97년 1월 현재 47.5%에 해당하는 2,513,000명에 달하는 등 작업자 수가 가장 많은 업종임에도 불구하고, 이에대한 실태 보고는 매우 적어 더 많은 연구 와 조사가 필요한 실정이다. 특히'95년 미구 제조업에서의 누적외상성질환 발생율(10.0건/1000명당)을 적용하면 우리 나라에서의 누적외상성 질환자 수를 약 25,130여명 정도로 추정할 수 있다. 본 연구에 서는 누적외상성질환과 관련하여 법제도상의 문제, 직업병 인정기준에 관한 문제, 의학적 관리상의 문 제, 작업환경 평가 및 관리에 관한 문제, 사업장 내 보건관리의 문제에 대한 쟁점 사항 및 이의 분석을 행하였다.