• Title/Summary/Keyword: Visual fatigue

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The Effect of Visual Feedback of Head Angles With Using a Mobile Posture-Aware System on Craniocervical Angle and Neck and Shoulder Muscles Fatigue During Watching the Smartphone

  • Kim, Su Jeong;Jeong, So Yeon;Yoon, Tae Lim
    • The Journal of Korean Physical Therapy
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    • v.30 no.2
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    • pp.47-53
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    • 2018
  • Purpose: To find the effect of visual feedback of head angle with using a mobile posture-aware system on craniocervical angle and neck and shoulder muscles fatigue for preventing or decreasing the forward head posture. Methods: Twenty-four healthy young adults in Chungbuk to participate in this study. The subjects started to watch a movie clip for 10 minutes with visual feedback in $0^{\circ}$, $30^{\circ}$, and $60^{\circ}$ of head angles. During the task, surface electromyography (EMG) was used to collect data from the upper trapezius (UT), sternocleidomasetoid muscle (SCM), cervical erecter spinae (CES) during watching the smartphone. Craniocervical angles were measured using a sagittal-view photograph of the subject in a sitting posture. A one-way repeated analysis of variance with a significant level of 0.05 used for statistical analysis. Results: Craniocervical angle with $0^{\circ}$ visual feedback was significantly greater than $30^{\circ}$ and $60^{\circ}$. Craniocervical angle with $30^{\circ}$ visual feedback was significantly greater than $60^{\circ}$. In addition, MDF of UT muscles in $0^{\circ}$ and $30^{\circ}$ of visual feedback was significantly greater than $60^{\circ}$. Conclusion: We concluded that $0^{\circ}$ visual feedback of head angle with using a mobile posture-aware system would be beneficial to prevent or decrease forward head posture during watching a smartphone. We also could recommend using of $30^{\circ}$ visual feedback in case of caring UT muscle fatigue primarily.

Study on the change of the fatigue scale by Sasang Constitutional herbal tea (피로 호소 환자의 사상체질 약차 복용 전후 변화 연구)

  • Bae, Young Chun;Joo, Jong Cheon
    • Journal of the Korean Institute of Oriental Medical Informatics
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    • v.19 no.2
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    • pp.21-28
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    • 2013
  • Background The aim of this study is assessing the adaption of the Sasang Constitutional herbal tea to the patient complained fatigue. Method Five times assessments were accomplished for 8 weeks using Chalder fatigue scale and visual analogue scale of health status. Herbal tea was served on the point of 4 weeks from 1st visit. Results Chalder fatigue scale and visual analogue scale of health status were significantly improved. Conclusion Sasang Constitutional herbal tea can be used for the control of chronic fatigue.

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An experimental study on search speed and error rate according to Korean letter size and font on search task with VDT (VDT 화면에서 한글의 글자크기와 서체에 따른 탐색속도와 오류율에 관한 실험적 연구)

  • 황우상;이동춘;이상도;이진호
    • Journal of the Ergonomics Society of Korea
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    • v.16 no.2
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    • pp.29-38
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    • 1997
  • The research on the factors which effect on legibility is mainly utilized as the basic data of selecting the standard guideline of VDT screen. But the research on Korean is scarcer than that of English. Furthermore, it is unreasonable to apply the results of the foreign language to Korean, beause of the difference between the typography of English and that of Korean. Therefore, more systematic and ergonomic research of the Korean typography on VDT screen is needed. In this paper, an experimental study on search speed and error rate is designed and performed according to different Korean letter size and font on search task with VDT. The experimental screen based on popular Ming and Gothic style is made up of total 12 artificial screens, each 6 different font size. As the criteria of the performance, searching speed(s.s.) and error rate (e) are selected, and CFF value is measured to evaluate user's visual fatigue. The results of experiment in font show that the Korean Gothic style is superior to the Korean Ming style in user's visual performance. The letter size that gives user the optimal performance ranges from the visual angle 39.8' to 55.5' in Ming style, from the visual angle 39.8' to 52.6' in Gothic systle. In visual fatigue experiment, the better performance of letter size is, the less tired user feels. And the smaller letter size is, the more tired user feels. There is no relationship between font and user's visual fatigue.

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Visual Fatigue Prediction for Stereoscopic Video Considering Individual Fusional Characteristics (시청자의 입체시 특성을 고려한 3D 비디오의 피로도 예측)

  • Kim, Dong-Hyun;Choi, Sung-Hwan;Sohn, Kwang-Hoon
    • Journal of Broadcast Engineering
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    • v.16 no.2
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    • pp.331-338
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    • 2011
  • In this paper, we propose a visual fatigue prediction metric which considers individual fusional characteristics for stereoscopic video. It predicts the visual fatigue level by examining the disparity and motion characteristics of 3D videos. In addition, we classified the viewers into 2 groups according to fusional limit and the slope of fusional response which are acquired from random dot stereogram test. Then, Pearson's and Spearman's correlation coefficient was measured between the proposed metrics and the subjective results, acquiring 80% and 79%.

Human Fatigue Inferring using Bayesian Networks (베이지안 네트워크를 이용한 인간의 피로도 추론)

  • Park, Ho-Sik;Nam, Kee-Hwan;Han, Jun-Hee;Jung, Yeon-Gil;Lee, Young-Sik;Ra, Sang-Dong;Bae, Cheol-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.1145-1148
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    • 2005
  • In this paper, we introduce a probabilistic model based on Bayesian networks (BNs) for inferring human fatigue by integrating information from various visual cues and certain relevant contextual information. Visual parameters, typically characterizing the cognitive states of a person including parameters related to eyelid movement, gaze, head movement, and facial expression, serve as the sensory observations. But, an individual visual cue or contextual Information does not provide enough information to determine human fatigue. Therefore in this paper, a Bayesian network model was developed to fuse as many as possible contextual and visual cue information for monitoring human fatigue. At the experiment results, display the utility of the proposed BNs for predicting and modeling fatigue.

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A Real-Time Virtual Re-Convergence Hardware Platform

  • Kim, Jae-Gon;Kim, Jong-Hak;Ham, Hun-Ho;Kim, Jueng-Hun;Park, Chan-Oh;Park, Soon-Suk;Cho, Jun-Dong
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.2
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    • pp.127-138
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    • 2012
  • In this paper, we propose a real-time virtual re-convergence hardware platform especially to reduce the visual fatigue caused by stereoscopy. Our unique idea to reduce visual fatigue is to utilize the virtual re-convergence based on the optimized disparity-map that contains more depth information in the negative disparity area than in the positive area. Our virtual re-convergence hardware platform, which consists of image rectification, disparity estimation, depth post-processing, and virtual view control, is realized in real time with 60 fps on a single Xilinx Virtex-5 FPGA chip.

The Effects of Self-acupressure on the Visual Health of College Students (자가 경혈지압이 대학생의 눈 건강에 미치는 효과)

  • Kim, Mee-Kyung;Yoon, Hyun-Min;Jung, Hyang-Mi
    • Journal of Acupuncture Research
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    • v.29 no.5
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    • pp.39-50
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    • 2012
  • Objectives : The purpose of this study was to identify the effects of self-acupressure on the visual health of college students. Methods : A nonequivalent control group pretest-posttest design was used. Participants were determined by OSDI(ocular surface disease index) and the Schirmer test, they were assigned to an experimental group of 22 and control group of 22. The experimental group participated in self-acupressure, which were practiced 2 times a day, 5 days a week for 4 weeks. Results : Scores of ocular surface disease index, Schirmer test and ocular fatigue were significantly better in the experimental group after the intervention compared to the control group. Conclusions : The result indicate that self-acupressure is an effective nursing intervention for improving the dry eye syndrome and decreasing ocular fatigue in college students.

Clinical Consideration of Visual Fatigue on 3D Images (3D 영상 시청에 대한 시각적 피로도의 임상적 고찰)

  • Kim, Jung-Ho;Son, Jeong-Sik;Park, Sung-Jin;Kwon, Soon-Chul
    • 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.