• Title/Summary/Keyword: Visual Fatigue

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Relationship between Reading Speed and Blinking Rate according to Longitudinal Chromatic Aberration during Book Reading (종이책 독서 시 종색수차에 따른 읽기속도와 순목횟수의 상관관계)

  • Kim, Se-il;Park, Mijung;Kim, So Ra
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.369-375
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    • 2015
  • Purpose: The current study was performed to estimate the changes in reading speed and blinking rate according to different background colors when reading paper book and further investigate their correlation. Methods: Twenty-nine adults (10 males, 19 females) who consented to the present study and had no ocular disease, ocular surgery history showing normal binocular vision were participated into the study. The subjects were asked to read the novels with black letter printed on white, red, green and blue background for 15 min, respectively. Then, the reading speed per page and blinking rate per page were measured during reading and analyzed according to background colors. Results: Reading speed per page according to the background color showed a tendency to accelerate in the white and green background as the reading time increased however, it was almost unchanged in the blue background and rather decelerated in the red background. On the other hand, the blinking rate per page tended to decrease in all background as the reading time was increased however, the smallest reduction was shown in the red background. There was a correlation that the reading speed increased as the blinking rate decreased in all backgrounds and the best correlation was shown in the green background. Conclusions: From the results, a correlation between the increasing reading speed and the reducing blinking rate while reading paper book with same demand on accommodation and convergence was confirmed however, the change in blinking rate and reading speed was varied depending on the main wavelength of light. It might mean that the working speed and visual fatigue can be varied depending on the difference of main wavelength when doing near work. Thus, it can be suggested that the adjustment of working environment and conditions should be made according to the kind of required perception.

Research a Person's Eyesight Changes on According to the Optimum Color Temperature for the Stand Lamp Using White Light LED Sources (백색광 LED를 사용한 독서등의 최적 색온도에 따른 사람의 시력 변화 연구)

  • Kim, Juhyun;Chang, Wonbeom;Lee, Seokhwan;Jung, Kwangkyo;Kim, Donghyun;Kim, Jeongmi;Ryu, Jaejun;Moon, Seongdeuk;Lee, Seunghyun;Ko, Youngsu;Huh, San;Jang, Mina;Jung, Changho;Chang, Jiho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.1
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    • pp.80-82
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    • 2013
  • White light emitting diode (LED) determined the most appropriate color temperature in reading lighting evaluated fatigue degree of eye according to color temperature. The eye fatigue degrees are determined by brightness and color temperature. Therefore, we measured the results of eyes test according to the change of color temperature and brightness. Experiments except for astigmatic corrected visual acuity of 0.8 more and age 20 to 25 years old, male and female college students was conducted in 100 patients. And constant illumination conditions, visual acuity was measured by varying the color temperature. The optometry at 10 minutes in the darkroom adapted eye. And then the temperature of $25{\pm}3$ degrees, the humidity was carried out at $50{\pm}5%$. As a result of typical color temperature of white light (5,600 K) has identification of the readability.

The Study for Fracture in the First Stage Blade of Aircraft Engine (항공기엔진용 1단계 터빈블레이드에 대한 파손 연구)

  • Yoon, Youngwoung;Park, Hyoungkyu;Kim, Jeong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.10
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    • pp.806-813
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    • 2018
  • The fracture of a turbine blade of aerospace engine is presented. Although there are a lot of causes and failure modes in blades, the main failure modes are two ways that fracture and fatigue. Degradation of blade material affects most failure modes. Total propagation of failure in this study specifies failure of fracture type. Some section appears fatigue mode. Especially since this study describes analysis of failure for blade in high temperature, it can be a case in point. Analysed blade is Ni super alloy. Investigations of blade are visual inspection, material, microstructure, high temperature stress rupture creep test, analysis and fracture surface, etc. The root cause for fracture was stress rupture due to abnormal thermal environment. Thermal property of Ni super alloy is excellent but if each chemical composition of alloys are different due to change mechanical properties, selection of material is very important.

Effectiveness of Additional Acupuncture Therapy for Lung Cancer Patients - A single group before-and-after, preliminary study - (폐암 환자에 대한 부가적인 침치료 효과 - 단일군, 전후, 예비임상 연구 -)

  • Kim, Do Hyung;Jeon, Doo Soo;Park, Seung Chan;Lee, Seung Eun;Cho, Woo Hyun;Han, Chang Woo;Kim, So Yeon;Choi, Jun-Yong;Kim, Yun Seong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.1
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    • pp.82-88
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    • 2014
  • This study is a single group before-and-after study aimed to evaluate the effectiveness of additional acupuncture therapy for lung cancer patients being treated with chemotherapy. Acupuncture therapy was conducted twice a day at least for a week. The effectiveness outcome measures were the Korean Functional Assessment of Cancer Therapy (FACT-L) and the Korean Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) at the baseline, discharge and four weeks after discharge, and visual analogue scale(VAS) checked daily from the baseline to discharge. Ten patients were enrolled, one patient had excluded due to acute exacerbation of lung cancer. The data of nine patients showed some improvement in all of FACT-L, FACIT-F and VAS, however, there were no statistical significance. Additional acupuncture therapy for lung cancer patients treated with chemotherapy might be beneficial to improve the quality of life(QoL) and to improve fatigue. Prospective trials with complex traditional Korean medicine interventions are needed to further investigation.

Clinical Trial for the Heat-Rising Action of Ginseng and Cultivated Wild Ginseng to The Subject Diagnosed as Heat Pattern by Cold-Heat Patternization (한열변증을 통한 열증 대상자에 산양삼과 재배인삼의 상부 승열 작용에 대한 인체적용시험)

  • Yoo, Su-Jeong;Ko, Sung-Kwon;Kim, Hyeong-Jun
    • The Journal of Korean Obstetrics and Gynecology
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    • v.30 no.4
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    • pp.45-58
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    • 2017
  • Objectives: The aim of this trial is to investigate the effect of Ginseng and Wild Cultivated Ginseng to Heat pattern subject. Methods: Eighty-nine Subjects were diagnosed as heat pattern by Cold-Heat Patternization and divided into Ginseng group (n=30), Wild Cultivated Ginseng group (n=31) and Placebo group (n=28) in their 1 st visit. In each visit, The researchers measured the subject's facial temperature using the infrared thermometer (Testo 835-T1). After that, The subjects were asked to mark the current score of flushing on the Visual Analogue Scale (VAS) and to complete the Chalder-Fatigue Scale (CFS) in each visit. The subjects took the test drug for one week and returned the remaining drug on the 2nd visit. The trial result was analyzed with one-way ANOVA using SPSS for Windows version 18. Results: 1. Systolic blood pressure was significantly lower in the Ginseng group and Wild Cultivated Ginseng group than in the control group (p=0.021). 2. There was no significant difference in facial temperature between each groups. 3. The current score of flushing showed the greatest decrease in the Ginseng group compared to the other groups but there was no significant difference (p=0.205). 4. The score of Chalder-Fatigue Scale was decreased in all groups but not statistically significant (p=0.180). Conclusions: This study showed that taking Ginseng extract and Wild Cultivated Ginseng extract do not affect to heat-rising reaction to the subjects diagnosed as heat pattern.

Effect of rapid rise in suffering rescue activity on cortisol and human symptom (수난 구조 활동에서의 급상승이 코르티솔 및 인체증상에 미치는 영향)

  • Jeon, Jai-In
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.3
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    • pp.99-104
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    • 2022
  • This study was to analyze the effects of sudden rise in cortisol and human symptoms in the situation of rescue at river, The experimental results are as follows. The subjects were A, B, C, and the values of cortisol elevation before and after diving were 6.30ug/dl, 6.50ug/dl, and 6.57ug/dl, respectively. However, in the subject D, the elevation of cortisol before and after diving was significantly elevated to 11.00ug/dl. The reason for this is thought to be the depletion of physical strength through weighty due to the inferiority of the underwater view and tense during the sudden rise. The subjects E showed significantly lower cortisol elevation before and after diving, as 4.28ug/dl, because the age of E was the youngest of the subjects and the anxiety was low due to abundant experience of deep sea diving. Fatigue is 7 to 8, anxiety is 7 to 9, Both showed high values. Psychological strain increased fatigue in underwater search, and poor visual field seemed to increase anxiety. The research results will be provided as empirical data on the safe underwater search activities of rescuers.

Effects of a Posture Correction Feedback System on Upper Body Posture, Muscle Activity, and Fatigue During Computer Typing

  • Subin Kim;Chunghwi Yi;Seohyun Kim;Gyuhyun Han;Onebin Lim
    • Physical Therapy Korea
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    • v.30 no.3
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    • pp.221-229
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    • 2023
  • Background: In modern society, the use of computers accounts for a large proportion of our daily lives. Although substantial research is being actively conducted on musculoskeletal diseases resulting from computer use, there has been a recent surge in interest in improving the working environment for prevention. Objects: This study aimed to examine the effects of posture correction feedback (PCF) on changes in neck posture and muscle activation during computer typing. Methods: The participants performed a computer typing task in two sessions, each lasting 16 minutes. The participant's dominant side was photographed and analyzed using ImageJ software to verify neck posture. Surface electromyography (EMG) was used to confirm the participant's cervical erector spinae (CES) and upper trapezius muscle activities. The EMG signal was analyzed using the percentage of reference voluntary contraction and amplitude probability distribution function (APDF). In the second session, visual and auditory feedback for posture correction was provided if the neck was flexed by more than 15° in the initial position during computer typing. A 20-minute rest period was provided between the two sessions. Results: The neck angle (p = 0.014), CES muscle activity (p = 0.008), and APDF (p = 0.015) showed significant differences depending on the presence of the PCF. Furthermore, significant differences were observed regarding the CES muscle activity (p = 0.001) and APDF (p = 0.002) over time. Conclusion: Our study showed that the feedback system can correct poor posture and reduces unnecessary muscle activation during computer work. The improved neck posture and reduced CES muscle activity observed in this study suggest that neck pain can be prevented. Based on these results, we suggest that the PCF system can be used to prevent neck pain.

The effects of mask applied aromatherapy on allergic rhinitis symptoms, fatigue, and quality of life related to allergic rhinitis in the COVID-19 era: a randomized controlled trial

  • Jihoo Her;Myung-Haeng Hur
    • Journal of Korean Biological Nursing Science
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    • v.26 no.3
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    • pp.177-184
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    • 2024
  • Purpose: Even after allergic rhinitis is diagnosed and treated, various symptoms such as runny nose, sneezing, and itchy nose recur periodically due to various environmental factors. Methods: This randomized controlled trial was conducted to confirm the effectiveness of mask-based aromatherapy as a method of alleviating allergic rhinitis during the coronavirus disease 2019 (COVID-19) pandemic. The study participants were adults between the ages of 19 and 60 who were diagnosed with allergic rhinitis and had a Total Nasal Symptom Score (TNSS) of 2 or more. Participants were randomly assigned to an aromatherapy group that was provided aromatherapy essential oils and a control group that did not receive aromatherapy. Participants in the aromatherapy group were asked to drop an aromatherapy essential oil onto a disposable face mask and wear it twice a day for two weeks. Results: The aromatherapy group experience significant alleviation of allergic rhinitis symptoms (visual analogue scale, F = 11.22, p < .001; TNSS, F = 15.82, p < .001). The aromatherapy group also showed significantly higher improvements in fatigue (F = 8.28, p < .001), allergic rhinitis-specific quality of life (F = 11.12, p < . 001). Conclusion: The oils used in this study appeared to be effective in relieving the symptoms of allergic rhinitis. In particular, the mask drop inhalation method was applied in light of mandatory mask-wearing due to the global COVID-19 pandemic during this study period. Mask drop inhalation is a method of inhaling oil close to the nose and is considered an effective method for reducing the inconvenience of applying oil.

Evaluation of sleep quality and stress response in patients requiring dental prosthetic treatment (치과보철치료를 요하는 환자에서의 수면질과 스트레스 반응 평가)

  • Jeon, Hye-Mi;Jung, Kyoung-Hwa;Choi, Na-Rae;Song, Jae-Min;Lee, So-Hyoun;Kim, So-Yeun
    • The Journal of Korean Academy of Prosthodontics
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    • v.59 no.2
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    • pp.181-189
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    • 2021
  • Purpose: The purpose of this study is to investigate the stress response and sleep state of the new patients who visit the hospital for prosthodontic treatment due to tooth loss to make reference to further treatment direction. Materials and methods: Examinations, consultations, and surveys were conducted on 236 patients (94 males, 142 females, and 24-86 years old), who newly registered at the department of prosthodontics at Pusan national university hospital, for 2 years from 2018. The number of remaining teeth, edentulous arch, possibility of mastication, and future prosthetic treatment directions were recorded. The visual analogue scale (VAS), stress response inventory (SRI) and Insomnia severity index (ISI) were used as tools to measure patient's subjective discomfort, stress response, and sleep status. Results: Among the entire prosthodontic patient group, the average value of 'fatigue' was significantly higher among the 7 items of SRI, and the value of 'aggression' was significantly lower (P<.001). There are a significant difference between the edentulous and full dentition in the oral discomfort value measured by VAS (P=.004). In cases where less than 20 teeth remain, mastication is impossible, and patients who are planning treatment with removable prostheses, VAS value and 'depression' and 'fatigue' values in SRI were higher than those in the reverse case (P<.05). The patients showed severe level in VAS value have high value of 'tension', 'somatization', 'depression', 'fatigue'and 'frustration'in SRI than non-serious patients (P<.05). Clinical insomnia occurred in 11.4% of all patients, and women had significantly lower sleep quality than men (P=.044). Patients with insomnia showed significantly higher scores on the VAS value and all 7 SRI items than those of normal sleepers (P<.05). Conclusion: The new prosthetics had high 'fatigue' value among the 7 items of SRI. The oral condition, number of residual teeth and mastication function and clinical insomnia affected oral discomfort and the stress response.

A Study on Technical Elements for Vision Therapy based on VR HMD (VR HMD에서의 비전 테라피 활용을 위한 기술 요소 연구)

  • Choi, Sangmi;Kim, Jungho;Kwon, Soonchul;Lee, Seunghyun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.12
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    • pp.161-168
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    • 2016
  • Thanks to mass production and provision of smartphones and the HMD (head mounted display), VR (virtual reality) is now being applied to various areas. The VR HMD is the interface equipment which allows users to have realistic experiences through human sensory organs such as vision and auditory sense. Since the majority of VR equipment is operated by the display for both eyes, 360-degree video content and the depth information, the VR mechanism is closely related to human senses, especially vision. Previous studies have focused on how to minimize negative impact such as motion sickness or visual fatigue. Little attention has been paid on research about the visual treatment. Therefore, the focus of this study is to develop technical elements for utilization of vision therapy with the VR HMD and explore possible areas to apply it. To this end, we analyzed the past case studies and technical elements to identify 16 areas for vision therapy. We also developed the optical parameters for utilization of the VR HMD visual targets. The result of this study is expected to be utilized for development of visual targets for vision therapy based on the VR HMD.