• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.10 no.2
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• pp.73-82
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• 2004

Objectives : In order to develop the measuring tool of visual display terminal (VDT) syndrome and investigate the variables affecting the development of VDT syndrome. Methods : A questionnaire study accompanied with the evaluation of working environment was performed with 42 VDT users from banking operations. Results : As a results of analysis with data colleted by newly developed questionnaire, VDT syndrome included five factors named as eye-related component, and psychological component. general body discomfort component. musculoskeletal component, and skin-related component. The scores of eye-related symptoms was 15.17, scores of psychological symptoms was 7.36, scores of general body discomfort symptoms was 10.52, scores of musculoskeletal symptoms was 9.38, scores of skin-related symptoms was 3.67, and total scores was 46.10. Scores of 2.05 eye fatigue in the level of eye-related symptoms were higher significantly. Scores 50.52 of female was statistically higher than scores 41.67 of male. Conclusions : The subjective symptoms of VDT syndrome scores was significantly associated with gender and age.

• Smart Media Journal
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• v.3 no.1
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• pp.52-62
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• 2014

Prevalence of common three-dimensional display progresses, increasing the demand for three-dimensional content. Starting from the year 2010 to meet increasing 2D to 3D conversion is insufficient to meet demand content was presented as an alternative. But, Convert 2D to 3D stereo effect only emphasizes content production as a three-dimensional visual fatigue and the degradation of the Quality problems are pointed out. In this study, opened in 2011 'Scenes Guan', the 13 selected Scene is made of the three-dimensional transform the content and the Quality of the transformation applied to the Depth-Map is a visual representation of three-dimensional fatigue and, the adequacy of whether the expert has group interviews and surveys were conducted. Many of the changes are applied to the motion picture of the three-dimensional configurations of Depth-Map conversion technology used in many ways before and after the analysis of the relationship of cascade configurations to create a depth map to the stage. Experiments, presented in this study is a three-dimensional configuration of Depth-Map transformation can lower the production of a three-dimensional visual fatigue and improve the results obtained for a reasonable place was more than half of the experiment accepted the expert group to show a positive reaction were. The results of this study with a rapid movement to convert 2D images into 3D images of applying Depth-map configuration cascade manner to reduce the visual fatigue, to increase the efficiency, and has a three-dimensional perception is the result derived.

• Journal of the Korea Society of Computer and Information
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• v.24 no.12
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• pp.75-84
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• 2019

The Naval Combat System has several equipment needed to operate the system, such as radar equipment, underwater sensor equipment, guns and missile control and armed control equipment, and a multi function console is configured to control it. The multi function console is equipped with HCI(Human Computer Interaction)-based software for displaying the status information of equipment and controlling equipment, and the operator uses the installed software to operate the Naval Combat System. However, when operating a Naval Combat System for a long time, there are problems such as physical discomfort caused by the structure of the multi function console display and increase in fatigue of the person who operates various and complicated user interface configuration. These issues are important factors in reducing Naval Combat System operability. In order to solve these issues, in this paper, based on a questionnaire survey conducted for Naval Combat System development personnel, multi function console screen design to reduce physical discomfort and HCI design to reduce fatigue and increase intuition are proposed. The proposed design is expected to provide convenience to future Naval Combat System operators and improve operation over existing Naval Combat System.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.53-58
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• 2006

The purpose of this study was to test the safety of the heel rest which was made for reducing the automobile driver's muscle fatigue with automatic transmission. Sixty subjects participated in the test, including ten males and ten females in 30s, 40s, 50s, respectively. Simulator consisted of automobile cockpit, accelerator and brake pedal sensor, heel rest. and driving displays. 30 seconds were given to subjects to be accustomed to the simulator environment. They also had one pre-trial to use the brake pedal according to the experimental scenario. They were told to step on the brake pedal immediately as soon as the red light was on the display The reaction time representing the foot travel time between accelerator and brake pedal was measured with/without the heel rest. In results, there was no significant difference in reaction time between conditions with/without heel rest. The result indicated that the heel rest used in this study would be a safe accessory for drivers who need to reduce the fatigue of the muscle or joint during driving.

• Imaging Science in Dentistry
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• v.41 no.1
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• pp.11-16
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• 2011

Purpose : The aim of this study was to evaluate the effect of liquid crystal display (LCD) monitor type and observer experience on the diagnostic performance in soft-copy interpretations of maxillary sinus inflammatory lesions on panoramic radiographs. Materials and Methods : Ninety maxillary sinuses on panoramic images were grouped into negative and positive groups according to the presence of inflammatory lesions, using CT for confirmation. Monochrome and color LCDs were used. Six observers participated and ROC analysis was performed to evaluate the diagnostic performance. The reading time, fatigue score, and inter-/intra-observer agreements were assessed. Results : The interpretation of maxillary sinus inflammatory lesions was affected by the LCD monitor type used and by the experience of the observer. The reading time was not significantly different, however the fatigue score was significantly different between two LCD monitors. Inter-observer agreement was relatively good in experienced observers, while the intra-observer agreement for all observers was good with monochrome LCD but not with color LCD. Conclusion : The less experienced observers showed lowered diagnostic ability with a general color LCD.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.74-85
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• 2012

In this paper, we propose a optical property correction technique for a low-cost heterogeneous stereoscopic camera. Three main optical properties of a stereoscopic camera are zoom, focus, and DOF(depth of field). The difference or mis-match of these properties between two stereoscopic videos are the main causes of the visual fatigue to human eyes. The proposed correction technique reduces the difference of the optical properties between the stereoscopic videos and produces high-quality stereoscopic videos. To correct the zoom difference, a LUT(look-up table) is established to match the zoom ratio between the stereoscopic videos. To correct the DOF difference, the magnitude of image edge is measured and the lens iris is changed to control the DOF of the camera. A vertical-type stereoscopic rig is developed for the experiments of the optical property correction. Based on the experimental results, we find that a low-cost heterogeneous stereoscopic camera can be implemented, which can yield low visual fatigue to human eyes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2865-2874
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• 2013

Recently, most of movies top-ranked in the box office are screening in Stereoscopic 3D, and the world's leading electronics companies such as Samsung and LG are getting the hots for 3DTV sales. However, each person has different binocular disparity and different viewing distance, and thus he or she feels the severe visual fatigue and headaches if he or she is watching 3D content with the same binocular disparity, which is very different from things he or she feels in the real world. To solve this problem, this paper proposes and implement a 3D rendering system that correct the disparity of 3D content by reflecting binocular distance and viewing distance. Then, the computational complexity is analyzed. Optical-flow and Warping algorithms turn out to consume 732 seconds and 5.7 seconds per frame, respectively. Therefore, a dedicated chip-set for both blocks is strongly required for real-time HD 3D display.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.4
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• pp.195-202
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• 2016

There have been many studies on subject tests for 3D contents using 3D glasses, but there is a limited research for 3D contents using autostereoscopic display. In this study, we investigated to assess usability of electroencephalogram (EEG) as an objective evaluation for 3D contents with different quality using autosteroscopic display, especially for lenticular lens type. The image with optimal quality and the image with distorted quality were separately generated for autostereosopic display with lenticular lens type and displayed sequentially through lenticular lens for 26 subjects. EEG signals of 8 channels from 26 subjects exposed to those images were detected and correlation between EEG signal and the quality of 3D images were statistically evaluated to check differences between optimal and distorted 3D contents. What we found was that there was no statistical significance for a wave vibration, however b wave vibration shows statistically significant between optimal and distorted 3D contents. b wave vibration observed for the distorted 3D image was stronger than that for the optimal 3D image. This results suggest that subjects viewing the distorted 3D contents through lenticular lens experience more discomfort or fatigue than those for the optimum 3D contents, which resulting in the greater b wave activity for those watching the distorted 3D contents. In conclusion, these results confirm that electroencephalogram (EEG) analysis can be used as a tool for objective evaluation of 3D contents using autosteroscopic display with lenticular lens type.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.267-280
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• 2017

Objective: The aim of this study is to investigate key user experience factors of interactions for Head Mounted Display (HMD) devices in the Virtual Reality Environment (VRE). Background: Virtual reality interaction research has been conducted steadily, while interaction methods and virtual reality devices have improved. Recently, all of the virtual reality devices are head mounted display based ones. Also, HMD-based interaction types include Remote Controller, Head Tracking, and Hand Gesture. However, there is few study on usability evaluation of virtual reality. Especially, the usability of HMD-based virtual reality was not investigated. Therefore, it is necessary to study the usability of HMD-based virtual reality. Method: HMD-based VR devices released recently have only three interaction types, 'Remote Controller', 'Head Tracking', and 'Hand Gesture'. We search 113 types of research to check the user experience factors or evaluation scales by interaction type. Finally, the key user experience factors or relevant evaluation scales are summarized considering the frequency used in the studies. Results: There are various key user experience factors by each interaction type. First, Remote controller's key user experience factors are 'Ease of learning', 'Ease of use', 'Satisfaction', 'Effectiveness', and 'Efficiency'. Also, Head tracking's key user experience factors are 'Sickness', 'Immersion', 'Intuitiveness', 'Stress', 'Fatigue', and 'Ease of learning'. Finally, Hand gesture's key user experience factors are 'Ease of learning', 'Ease of use', 'Feedback', 'Consistent', 'Simple', 'Natural', 'Efficiency', 'Responsiveness', 'Usefulness', 'Intuitiveness', and 'Adaptability'. Conclusion: We identified key user experience factors for each interaction type through literature review. However, we did not consider objective measures because each study adopted different performance factors. Application: The results of this study can be used when evaluating HMD-based interactions in virtual reality in terms of usability.

• 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 $3.24{\Delta}$.