• Journal of Information Display
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• v.10 no.4
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• pp.188-194
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• 2009

Conventional stereoscopic (3D) displays using binocular parallax generate unnatural conflicts between convergence and accommodation. These conflicts can affect the observer's ability to fuse binocular images and may cause visual fatigue. In this study, time series changes in visual fatigue and depth sensation when viewing stereoscopic images with changing parallax were examined. In particular, the physiological changes, including the subjective symptoms of visual fatigue, when viewing five parallax conditions, were examined. Then a comparative analysis of the 2D and 3D conditions was performed based on the visual function. To obtain data regarding the visual function, the time series changes in the spontaneous-blinking rate before and during the viewing of 3D images were measured. The time series change results suggest that 2D and 3D images cause significantly different types of visual fatigue over the range of binocular disparity.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1099-1102
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• 2009

Conventional stereoscopic (3D) displays using binocular parallax generate unnatural conflicts between convergence and accommodation. Those conflicts can affect the ability to fuse binocular images and may cause visual fatigue. This study examined time-series changes in visual fatigue and depth sensation while viewing stereoscopic images with changing parallax. We examined the physiological changes, including the subjective symptoms of visual fatigue, when viewing five parallax conditions. The time-series results suggest that 2D and 3D images produce significantly different types of visual fatigue over the range of binocular disparity.

• Journal of Korean Academy of Nursing
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• v.36 no.7
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• pp.1224-1231
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• 2006

Purpose: This study was conducted to identify comprehensive predictors of fatigue in cancer patients. Methods: One hundred ten cancer patients visiting in-patient or out-patient clinics of a university hospital located in Incheon participated in this study. Results: The hematologic indicators (WBC and Hemoglobin) were significant fo. explaining fatigue. The psychological factors of fatigue were statistically significant. Both anxiety and depression, included as psychological factors, were significant in explaining fatigue in cancer patients. The influence of physical factors on fatigue was also statistically significant. Among the variables included as physical factors, pain, nausea/vomiting/anorexia, and sleep disturbance were significant whereas, dyspnea was not significant. The influence of the daily activity factor on fatigue was statistically significant. Among the variables included as daily activity factors, regular exercise or not and the usual activity level were significant in explaining fatigue of cancer patients, while the level of rest was not statistically significant. Conclusions: From the study results fatigue of cancer patients appeared to be influenced by multidimensional factors, such as physiological, physical, psychological, and activity related factors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.160-166
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• 2016

Crew fatigue has been recognized as a major cause of maritime accidents. Systematic study on crew fatigue has a direct impact on the human factor, but the various measures being taken to prevent human error account for most of the causes of marine accidents situation are still insufficient. In this study, 128 people who have a variety of career and job types boarded the T/S Hanbada were analyzed the changes of fatigue during the 87-days a Maritime Silk Road Sailing Expedition. Crew fatigue was measured by period of time onboard classified as mental, physiological and physical changes through survey responses and individual interviews of nurses. Also, it was identified the fatigue factor through quantitative statistical analysis. As a result of repeated measures analysis of variance for the changes of fatigue in position and gender criteria in accordance with boarded period, the position-specific analysis was that Professor Rating group has appeared to feel more mental and physical fatigue than the student population. Also, the results of fatigability about the sex-specific analysis have been found that women feel more physical fatigue than men.

• Korean Journal of Materials Research
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• v.31 no.3
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• pp.172-180
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• 2021

In this study, using the plasma spray method, tensile and compression fatigue tests are performed in saline solution to examine the effect of Ti undercoat on corrosion fatigue behavior of alumina-coated specimens. The alumina-coated material using Ti in the undercoat shows better corrosion fatigue strength than the base material in the entire stress amplitude range. Fatigue cracking of UT specimens occurs in the recess formed by grit-blasting treatment and progresses toward the base metal. Subsequently, the undercoat is destroyed at a stage where the deformation of the undercoat cannot follow the crack opening displacement. The residual stress of the UT specimen has a tensile residual stress up to about 100 ㎛ below the surface of the base material; however, when the depth exceeds 100 ㎛, the residual stress becomes a compressive residual stress. In addition, the inside of the spray coating film is compressive residual stress, which contributes to improving the fatigue strength characteristics. A hardened layer due to grit-blasting treatment is formed near the surface of the UT specimen, contributing to the improvement of the fatigue strength characteristics. Since the natural potential of Ti spray coating film is slightly higher than that of the base material, it exhibits excellent corrosion resistance; however, when physiological saline intrudes, a galvanic battery is formed and the base material corrodes preferentially.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.1-7
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• 2010

Recently, the vehicle driving device has been designed for driver's convenience. Especially, the automobile industry develops the vehicle using the joystick instead of steering wheel from the concept car. The biggest strength of using the joystick is that the driver feels less workload and fatigue than when the driver uses steering wheel. However, this kind of study still needs more research and experiments for more accurate result. Therefore, this research evaluated workload according to the driving device by the survey and the measurement of physiological signal. The reason not only using the survey also using the measurement of physiological signal is to support the result of the survey which is not enough to bring the accurate result. There were tow different kinds of methods to carry out this research; SWAT (Subjective Workload Assessment Technique) for the survey and the biopac equipment for the measurement of physiological signal. Furthermore, previously established driving simulator, GPS (Global Positioning System), and Seoul-Cheonan virtual expressway DB were used for the experiment. As the result of the experiment with 13 subjects, it was certain that using joystick device brings less workload and fatigue to the drivers than using steering wheel following both methods-the survey and the measurement of physiological signal. Also, it confirmed the significant result from the SPSS (Statistical Package for the Social Sciences) statistics analysis program.

• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.791-796
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• 2007

Objective : This study was conducted to find the relationship between syndrome-differentiation and Sasang-constitution in chronic fatigue patients. Methods : The subjects were 72 adults with chronic fatigue who visited Dunsan Oriental Hospital of Daejeon University between March 2007 and April 2007. Their main complaint was fatigue for longer than 6 months and they did not have any physical or mental problems. We measured their fatigue degree by using Chalder fatigue scale and health habits. To evaluate relationship between syndrome-differentiation with sasang-constitution, The patients were divided into four syndrome-differentiations, such as liver and kidney asthenia of Yin, spleen and kidney deficiency of Yang, deficiency of lung and spleen qi, and deficiency of heart and spleen blood. We also diagnosed Sasang-constitution by using Questionnaire for Sasang Constitution Classification II (QSCCII). Results : Among the 72 patients, 41.4%, 34.5% and 24.1% of belonged in Soyangin, Soeumin and Taeumin respectively. Interestingly, we found a meaningful correlation between syndrome-differentiation and physiological function by Sasang-constitution. Conclusion : The result may help Oriental medicine understanding and treatment of chronic fatigue-related diseases and patients.

• Journal of Korean Physical Therapy Science
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• v.4 no.2
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• pp.391-397
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• 1997

The purposes of this study were to determine wether knee muscular fatigue affects on one-leg static standing balance. Sixty four healthy subjects were used for this study : 44 men and 20 women, with an average age of 19.52. One leg static standing balance was measured at pre-fatigue and post-fatigue by an instrumented balance assessment system(kinesthetic ability training balance platform) which is commercially available for testing or training balance. Isokinetic exercises were used to evoke muscle fatigue at 180 degree/see by Cybex 1200. One leg static standing balance ability was significantly decreased after knee muscular fatigue. Although these phenomenons were not clearly understood, these results have important implications for rehabilitation in fatigable patients. These results suggest that the excessive fatiguing during rehabilitation in patients with fatigable disease may increase risk of reinjury and falling injury due to balance disturbance. Further studies are required to determine the physiological mechanisms of muscle fatigue that can play in decreasing one-leg static standing balance ability.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.605-611
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• 2005

Chronic fatigue refers to the tiredness which disturbs one's daily activities and lasts more than six months without the sign of improvement by rest or sleep. Male chronic fatigue is included in internal injuries due to overstrain and exhaustion and closely related to river, spleen, stomach and kidney out of five Jang organs. Male chronic fatigue is based on the deficiency of Yang and aggravated by liquor, sex and emotional depression. Chronic fatigue has the following features in Hyungsang ; an inclination for lying: unwillingness to everything; drooping eyes and feeble voice; yellow pale complexion; withered ears; redness on the tip of nose; cheekbone, and lips; blood shot eyes; dryness and loss of hair. Male chronic fatigue usually attacks the persons of horse type and bird type because they are hyperactive compared with what they eat. The following medicines are commonly prescribed for the treatment of male chronic fatigue. Ssangwhatang, Sokunzungtang, and Yanghyulsamultang are commonly prescribed to horse type. Jaumkangwhatang, Chungsimyunzaum, Yookmijiwhangtang to bird type. Palmiwhan, Gozinumja. and Shinkihwan to fish type. Bozungikkitang, Galwhahaesungtang, Samchulgunbitang and Sipjundaebotang to turtle type.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.450-457
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• 2022

The construction industry is demanding, dynamic, and complex making it difficult for workers to recognize hazards. The nature of construction tasks exposes workers to several critical risk factors, such as a high rate of exertion and fatigue. Recent studies suggest that fatigue may impact hazard recognition in the construction industry. However, most studies rely on subjective measures when assessing the relationship between physical fatigue and hazard recognition, limiting such studies' efficacy. Thus, this study examined the relationship between physical fatigue and hazard recognition using a controlled experiment. Worker fatigue levels were captured using physiological data and a subjective exertion scale. The findings confirmed that physical exertion plays a significant role in hazard recognition skills (p < 0.05). This research contributes to theory and practice by providing a process for objectively assessing the influence of physical fatigue on worker safety and providing construction professionals with some critical insight needed to improve workplace safety.