• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.130-136
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• 2003

A FQI(fatigue quality index) analysis using the concept of SF(severity factor) is performed to various shape of elliptical hole. FQI is fatigue quality index to estimate the dynamic SF from static SF by finite element analysis. Since the SF is affected by the location of cutout in plate and radius ratio, static SF is analyzed with finite element method and forms the equation of FQI for predicting a dynamic SF. To examine the validity, dynamic SF is measured by photoelastics and thermalelastics for an epoxy resin plate with various elliptical holes under dynamic load.

• Korean journal of aerospace and environmental medicine
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• v.31 no.2
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• pp.38-44
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• 2021

Purpose: This study aimed to identify the prevalence of fatigue and its associated factors leading to the fatigue among Korean commercial airline pilots. Methods: An anonymous, web-based questionnaire collecting data on sleep related characteristics was completed by airline pilots. The final 1,029 samples of completed questionnaires were analyzed. The association of the risk factors with fatigue was determined using logistic regression analysis. Results: The prevalence of fatigue was 60% (Fatigue Severity Scale index≥3.2), disturbed sleep 28% (Pittsburgh Sleep Quality Index≥9), daytime sleepiness 17% (Epworth Sleepiness Scale≥10), and sleep apnea (Berlin Questionnaire≥2) 11%. The fully adjusted logistic regression showed that quality of life (odds ratio [OR]=0.16, confidence interval [CI]=0.11-0.24), daytime sleepiness (OR=1.26, CI=1.18-1.34), sleep quality (OR=1.44, CI=1.29-1.61), mental workload (OR=1.10, CI=1.05-1.14), vigorous physical activity (OR=0.82, CI=0.72-0.92), late starts (OR=1.25, CI=1.06-1.46) and average weekly flying hours (OR=1.02, CI=1.00-1.03) were associated with higher levels of fatigue. Conclusion: Lower quality of life, disturbed sleep, more subjective sleepiness, shorter sleep duration, higher mental workload, less vigorous physical activity, frequent late starts, and longer flying hour were shown to be risk factors for fatigue in airline pilots. These findings should be taken into account in the development of sleep and fatigue countermeasures for airline pilots.

• Korean Journal of Occupational Health Nursing
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• v.23 no.3
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• pp.171-179
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• 2014

Purpose: The purpose of this research was to provide baseline data by utilizing solutions to health problems caused by work-related stress and to examine a way of treatment by comparing and analyzing how the stresses link to fatigue and quality of researchers' life. Methods: A survey was conducted with 50 researchers working for in H research institute in Daejeon Metropolitan City from April 10th to May 10th, 2012 to examine the correlation of work stress, fatigue and quality of life. The data were analyzed using the Kruskal-Wallis test to look into examine the difference in work stress, fatigue, and quality of life. Also, the correlation of work stress, fatigue and quality of life was measured through by the Pearson correlation coefficient. The data collected through the questionnaires was were analyzed by SPSS 21.0 based on the significant level with a p-value, 0.05. Results: The results showed that fatigue was caused by work stresses in researchers and quality of life was ranked in a relatively low level. Correlation of work stresses, quality of life and fatigue and work stresses against mental health index was negative and fatigue against physical index was also negative. Conclusion: It is necessary to maintain more detailed provisions in order to improve mental health and stress level of researchers. Moreover, systematic, in-depth evaluation should be done to reduce researcher's work-related stress and fatigue. In addition, stress management and prevention program should be implemented for these researchers.

• Journal of Society of Preventive Korean Medicine
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• v.21 no.2
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• pp.35-44
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• 2017

Objectives : The purpose of this study was to investigate the association between quality of life and Mibyeong index of abnormal symptoms by the Mibyeong state. Methods : A total of 1,100 people were recruited into this study and were collected by specialized research company. The data were collected by personal information using MBI(Mibyeong Index) and SF-12 (Short form-12) and were analyzed with SPSS (version 21.0) computer program, and included Pearson's chi-square test, ANOVA, Pearson's correlation coefficient, and multiple regression analysis. Results : The Mibyeong Index which represents abnormal symptom type showed significant difference for Mibyeong state (p<.001). In Total subject, fatigue, pain, low sleep quality and indigestion were found to be significant predictors of PCS(Physical Component Summary). In Healthy group, pain was found to be significant predictor of PCS. In MI 1 group, fatigue, pain, indigestion and anxiety were found to be significant predictors of PCS. In MI 2 group, fatigue, pain and low sleep quality were found to be significant predictors of PCS. In Total subject, fatigue, depression, anger and anxiety were found to be significant predictors of MCS (Mental Component Summary). In Healthy group, indigestion and anxiety were found to be significant predictors of MCS. In MI 1 group, depression and anger were found to be significant predictors of MCS. In MI 2 group, fatigue and depression were found to be significant predictors of MCS. Conclusions : The relationship between Quality of life and MBI changes according to Mibyeong state. We expect that this result could be contribute to health management of people in Mibyeong state.

• Korean Journal of Adult Nursing
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• v.14 no.2
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• pp.205-212
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• 2002

Purpose: The purpose of this study was to investigate the level of nausea, vomiting, anorexia, fatigue and quality of life as well as to determine the relationship between those variables and identify the influencing factors on fatigue and quality of life in stomach cancer patients receiving adjuvant chemotherapy. Method: Subjects were 94 stomach cancer patients undergoing postoperational chemotherapy in a general hospital in Seoul. Nausea and vomiting were measured with Rhodes et al(1984) and anorexia with one 5-point item. Fatigue was measured using Lee's tool(1999) except open questions. The tool for quality of life was modified based on the Quality of Life Index by Padilla et al(1983). Result: Subjects reported low level of fatigue(mean=3.86, range=0-10) compared with the results of previous researches and moderate quality of life(mean=2.64, range=1-4). Fatigue was positively correlated with nausea, vomiting and anorexia(r=.21 ~ .55, p<.05). Quality of life was negatively correlated with nausea, vomiting, anorexia(r= -.24 ~ -.45, p<.05) and fatigue (r=-.61, p<.01). Multiple regression analysis revealed that activity level, vomiting before admission, anorexia during chemotherapy and age explained 52.8% of the variance in fatigue. Fatigue, anorexia before admission, age and sex explained 50.5% of the variance in quality of life. Fatigue and quality of life were not influenced by the stage of disease, nor weight change. Conclusion: These results may contribute to a better understanding of how much the side effects of anticancer drugs can affect fatigue and quality of life in cancer patients undergoing chemotherapy. Also it is the remarkable fact that symptoms remaining after discharge such as vomiting or anorexia continued until re-admission, contributing to patients fatigue and lowered their quality of life.

• Korean Journal of Adult Nursing
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• v.29 no.1
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• pp.87-97
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• 2017

Purpose: The purpose of this study was to investigate the relationship among sleep quality, heart rate variability (HRV), fatigue, depression, and anxiety reported by Korean adults. Methods: A cross-sectional study of 208 adults aged 20~60 years was conducted using a short-term HRV analysis and self-reported questionnaires of Pittsburgh Sleep Quality Index (PSQI), Fatigue Severity Scale, Beck Depression Inventory, and State Trait Anxiety Inventory. Results: Subjects with good sleep quality (PSQI $score{\leq}5$) had higher HRV total power (t=2.03, p=.043) and high-frequency (t=2.04, p=.043) with lower fatigue (t=-4.08, p<.001), depressive mood (t=-3.66, p<.001), and trait anxiety (t=-3.84, p<.001) than subjects with poor sleep quality. Poor sleep quality was negatively correlated with HRV total power (r=-.17, p=.016), high-frequency (r=-.14, p=.049), and positively fatigue (r=.39, p<.001), depression (r=.44, p<.001), state anxiety (r=.23, p=.001) and trait anxiety (r=.34, p<.001). Conclusion: The results indicated that sleep quality is correlated with HRV which reflects the activities of the autonomic nerve system, fatigue, depression, and anxiety in adults.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.1
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• pp.37-44
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• 2020

Previous studies have reported an association between poor sleep and various symptoms and diseases, such as fatigue, obesity, depression, and anxiety. The effects of poor sleep may differ by age and sex. In addition, sleep characteristics and their effects may vary according to Sasang constitutional type. The aim of this study was to investigate the associations between sleep quality, fatigue, and quality of life and to assess whether these differ by constitutional type. Participants were individuals aged 40-69 years living in two Korean communities in 2012-2014. Sleep quality, fatigue, and quality of life were measured using the Pittsburgh Sleep Quality Index (PSQI), the Fatigue Severity Scale, and the 12-item Short Form Health Survey, respectively. The effects of total PSQI score and PSQI component scores were analyzed using a generalized additive model. A Korean Sasang constitutional diagnostic questionnaire was used to assess Sasang constitution. Data for 5,793 participants were analyzed. Poor sleep quality was related to greater fatigue, and lower physical and mental quality of life. The PSQI components including subjective sleep quality, sleep latency, sleep disturbances, use of sleep medications, and daytime dysfunction were associated with fatigue and physical and mental quality of life. Sleep quality was significantly lower in So-Eum compared to So-Yang and Tae-Eum. PSQI component scores for fatigue and quality of life differed significantly by Sasang constitution: for Tae-Eum, sleep latency and use of sleep medications; for So-Eum, daytime dysfunction; and for So-Yang, use of sleep medications and daytime dysfunction. The effects of different aspects of sleep quality differ by Sasang constitution. To improve sleep quality, interventions need to be tailored to constitutional type.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.90-95
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• 2005

Most of mechanical structures are composed of many substructures connected to one another by various types of mechanical joints with various shapes of cutouts. It is important to study these connected structures under dynamic forces for evaluation of stress concentration. In this paper, a FQI(fatigue quality index) analysis using the concept of SF(severity factor) is performed to various shape of elliptical hole. The SF is affected by the location of cutout in plate and radius ratio, static SF is analyzed with finite element analysis and the equation of FQI for predicting a dynamic SF is formed.

• Journal of Korean Academy of Nursing
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• v.50 no.5
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• pp.646-657
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• 2020

Purpose: The purpose of this study was to identify the quality of sleep in novice and experienced shift work nurses and compare the factors associated with their quality of sleep. Methods: We analyzed the data of 192 and 256 novice and experienced nurses, respectively. The quality of sleep, sleep hygiene, job stress, and fatigue were measured using Insomnia Severity Index, Sleep Hygiene Practice Scale, the Korean Occupational Stress Scale, and Fatigue Severity Scale. Data were analyzed using SPSS 25.0 to calculate descriptive statistics and logistic regression. Results: Sleep quality was lower in experienced nurses (12.55 ± 5.71) than in novice nurses (11.18 ± 5.78). Fatigue was more severe in experienced nurses (4.47 ± 1.13) than in novice nurses (4.23 ± 1.12). In the logistic regression, factors related to sleep quality in novice nurses were sleep hygiene (odds ratio; OR = 1.06, p < .001) and fatigue (OR = 2.49, p < .001). Factors related to sleep quality in the experienced nurses were also sleep hygiene (OR = 1.04, p = .001) and fatigue (OR = 1.53, p = .012). Conclusion: Sleep quality of experienced nurses is lower than those of novice nurses. Factors associated with sleep quality in novice and experienced nurses are equally identified as sleep hygiene and fatigue. Therefore, personal efforts to improve sleep hygiene, such as providing comfortable sleep environment, are needed. Furthermore, organized efforts to decrease fatigue, such as constructing a working environment with a bright light at night and providing a fatigue-decreasing program that includes meditation, are required.

• Journal of Korean Traditional Oncology
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• v.26 no.1
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• pp.49-59
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• 2021

Objective: Insomnia is a very common symptom of cancer and has a substantial effect on the patients' quality of life. This study aimed to identify the effects of foot reflexology on insomnia in cancer patients. Methods: The study employed a before-after test design on a single group of 13 cancer patients with insomnia, selected by convenience sampling in Daegu. The foot reflexology treatment comprised 30-min sessions twice a week over four weeks. Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) were measured at the baseline, at 2 and 4 weeks, and after 4 weeks post treatment completion. Brief Fatigue Inventory-Korean (BFI-K), Functional Assessment of Cancer Therapy-General (FACT-G), and Heart Rate Variability (HRV) were measured at baseline, post-treatment, and 4 weeks after completing treatments. Results: Thirteen patients (mean age 44.77 ± 6.70 years), with thyroid, breast or cervical cancer, were included in the study. Post-treatment, PSQI (from 12.33 ± 3.17 to 8.54 ± 3.43, p<0.001), ISI (from 20.33 ± 3.88 to 13.38 ± 4.23, p<0.001), FACT-G (from 49.6 ± 13.27 to 61.35 ± 14.45, p<0.001), and BFI (from 6.46 ± 0.91 to 5.00 ± 2.02, p<0.001) scores improved significantly over those at the baseline. Conclusion: Foot reflexology can be a good alternative treatment to improve insomnia, fatigue, and quality of life in cancer patients