• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.13 no.2
• /
• pp.1-18
• /
• 2017

Metal fatigue is an important aging mechanism that material characteristics can be deteriorated when even a small load is applied repeatedly. An accurate fatigue evaluation is very important for component structural integrity and reliability. In the design stage of a nuclear power plant, the fatigue evaluations of the Class 1 components have to be performed. However, operating experience shows that the design evaluation can be very conservative due to conservatism in the transient severity and number of occurrence. Therefore, the fatigue monitoring system has been considered as a practical mean to ensure safe operation of the nuclear power plants. The fatigue monitoring system can quantify accumulated fatigue damage up to date for various plant conditions. The purpose of this paper is to describe the fatigue monitoring procedure and to introduce the fatigue monitoring program developed by the authors. The feasibility of the fatigue monitoring program is demonstrated by comparing with the actual operating data and finite element analysis results.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.05a
• /
• pp.539-544
• /
• 2003

우리나라는 급격한 경제의 발달과 더불어 자동차문화의 많은 변화를 가져왔다. 이러한 변화는 교통혼잡 및 교통사고로 사회의 중요한 이슈로 등장하였고, 사고에 따른 인적, 물적피해가 증가하고 그 심각도(Severity)가 더해지고 있는 실정이다.(중략)

• Korean Journal of Adult Nursing
• /
• v.29 no.2
• /
• pp.190-199
• /
• 2017

Purpose: The purpose of this study was to investigate the differences in sleep, fatigue, and neurocognitive function between shift nurses and non-shift nurses. Methods: A cross-sectional descriptive study design was used. A total of 100 nurses participated in the study. 50 were shift nurses and the remaining 50 were non-shift nurses. The Pittsburgh Sleep Quality Index, Fatigue Severity Scale, and a computerized neurocognitive function test (CNS Vital Signs-VS4) were administered to the subjects to assess verbal and visual memory, processing speed, reaction time, and simple attention. After the last night shift, the shift nurse conducted the study at around 8:00 am and the non-shift nurse participated after work. Results: Compared to non-shift nurses, shift nurses had a significantly lower sleep quality (p=.002) and higher fatigue (p=.001) and achieved significantly lower scores on verbal memory (p=.001), processing speed (p=.003), and reaction time (p=.018). There were significant correlations between sleep quality and processing speed (p=.042), and reaction time (p=.015) of shift nurses who were bad sleepers. Conclusion: This study findings suggest shift work could interfere with cognitive function. Personal and organizational programs should be developed to support their sleep and neurocognitive function.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.322-327
• /
• 2001

The internal leaks of RCS pressure boundary valves may cause thermal fatigue crack because of the TASCS in RCS branch line. After experienced unisolable piping failures in several PWR plants, many studies have peformed to understand these phenomena and various methods were applied to ensure the structural integrity of piping. In this paper, the cause of unisolable piping failures and the alternatives to prevent recurrence of failure were reviewed. Also, the severity of piping failure including susceptibility of valve leaks was evaluated for the Westinghouse 2-loop plant. The length of turbulent penetration on RHR inlet piping was measured and, thermal fluid analysis and fatigue analysis was performed for this piping. As a means of ensuring the structural integrity, temperature monitoring and specialized UT and other alternatives were compared for the further application.

• Sleep Medicine and Psychophysiology
• /
• v.19 no.2
• /
• pp.89-96
• /
• 2012

Objectives: Individuals differ in their biological rhythms. This study investigated the association between the morningness-eveningness and sleep patterns, daytime sleepiness and fatigue in Korean male adolescents. Methods: Participants were 501 eleventh grade male students ($16.9{\pm}0.2$ years of age) in one male high school in Seoul. Each student completed the Korean translation of composite scale (KtCS), Epworth sleepiness scale (ESS), Fatigue Severity Scale (FSS) and a questionnaire about their sleep schedule. Results: The evening group had shorter weekday sleep time than the intermediate (p<0.001) or morning group (p=0.029). The evening group had more daytime napping (16.8%, p<0.001), high rate of caffeine use (58.8%, p<0.001) and snoring (18.5%, p=0.037). The evening group showed more daytime sleepiness (8.7, SD=3.2, p<0.001) and severe fatigue (4.4, SD=1.2, p<0.001) than the intermediate or morning group. Conclusion: Adolescents with eveningness have higher problems in weekday sleep, daytime sleepiness and fatigue. An intervention program for sleep problem in these adolescents should be considered.

• International Journal of Contents
• /
• v.17 no.2
• /
• pp.20-31
• /
• 2021

This study aimed to pilot test a newly developed bilateral upper limb rehabilitation training program for improving the upper limb function of individuals with chronic stroke using a visual feedback method. The double-group pretest-posttest design pilot study included 10 individuals with chronic stroke (age >50 years). The intervention (four weekly meetings) consisted of five upper limb training protocols (wrist extension; forearm supination and pronation; elbow extension and shoulder flexion; weight-bearing shift; and shoulder, elbow, and wrist complex movements). Upper limb movement function recovery was assessed with the FuglMeyer Assessment of the Upper Extremity, the Wolf Motor Function Test, the Trunk Control Test, the modified Ashworth Scale, and the visual analog scale at baseline, immediately after, and four weeks after the intervention. The Fatigue Severity Scale was also employed. The Fugl-Meyer Assessment of the Upper Extremity and Wolf Motor Function Test showed significant improvement in upper limb motor function. The Trunk Control Test results increased slightly, and the modified Ashworth Scale decreased slightly, without statistical significance. The visual analog scale scores showed a significant decrease and the Fatigue Severity Scale scores were moderate or low. The bilateral upper limb training program using the visual feedback method could result in slight upper limb function improvements in individuals with chronic stroke.

• The Journal of Internal Korean Medicine
• /
• v.45 no.3
• /
• pp.478-487
• /
• 2024

Objectives: This case report describes good clinical progress in a patient with symptoms related to angina pectoris treated with a herbal medication. Methods: The 66-year-old male patient hospitalized in Chonnam National University Hospital (CNUH) in May 2020 for symptoms of dyspnea and chest pain was diagnosed with angina pectoris, medicated, underwent PCI in August 2020, and continued to take the medicine prescribed at CNUH during hospitalization. Korean medical treatments, including herbal medicines (Saengmaeg-san-hap-Bojungikgi-tang-gami, Yeonggyechulgam-tang), acupuncture, and cupping therapy were administered for 22 days. Symptom severity was assessed with a daily visual analog scale (VAS) for dyspnea and chest pain and standard deviation of NN (SDNN) score of heart rate variability. Results: Post-treatment, severity of dyspnea, chest pain, and fatigue reduced from VAS 7 to VAS 2, VAS 6 to VAS 1, and VAS 7 to VAS 1, respectively. The SDNN score improved from 16.474 ms to 23.270 ms. There were no side effects from Korean medicine treatment. Conclusion: Traditional Korean treatment could effectively treat symptoms related to angina pectoris.

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

• The Journal of the Society of Korean Medicine Diagnostics
• /
• v.17 no.3
• /
• pp.179-188
• /
• 2013

Objectives This study was designed to development the diagnosis indicators for the fatigue group without disease using analysis of questionnaire data. Methods The subjects were divided into three groups, the fatigue group with disease, the fatigue group without disease, non-fatigue group without disease. Thirteen kinds of questionnaire (Fatigue visual analogue scale, Fatigue severity scale, Pain visual analogue scale, Short-form McGill pain questionnaire score, Headache impact Test-6, Neck disability index, Oswestry low back pain disability questionnaire score, Blood stasis assessment scale, Physical activities questionnaire score, Beck depression inventory, Anger expression inventory score, Mood disability scale, Job stress scale) were carried out for the subjects. Results The results of this study are ; 1) The weight, the systolic and diastolic blood pressure were different among three groups. 2) Among nine questionnaires related to the physical or life conditions, the averages of eight questionnaires were not same one another. 3) Among four questionnaires related to the mental condition or autonomic nervous system, the averages of Beck depression inventory were not same one another. Conclusion The fatigue group without disease can be diagnosed through using the both the questionnaires related to the physical or life condition and the those related to the mental condition or autonomic nervous system.

• Journal of Home Health Care Nursing
• /
• v.29 no.3
• /
• pp.310-318
• /
• 2022

Purpose: This is a cross-sectional study aimed to investigate the effects of dry eye syndrome symptoms and eye fatigue on the vision-related quality of life (QOL) of middle-aged patients with dry eye syndrome. Methods: The participants of this study were 94 ophthalmology clinic outpatients aged 40-59 years who were diagnosed with dry eye syndrome at A and S Ophthalmology Clinics in D City, South Korea, and were exhibiting dry eye syndrome symptoms. Data were collected from July 5, 2021 to July 22, 2021, and analyzed using independent t-test, analysis of variance, Scheffe test, Pearson's correlation coefficient, and multiple regression analysis using the SPSS/WIN 25.0 program. Results: The severity of dry eye syndrome symptoms and asthenopia (r=.73, p<.001) in the participants were positively correlated, whereas the severity of dry eye syndrome symptoms and vision-related quality of life (r=-.76, p<.001) were negatively correlated. Additionally, there was a negative relationship between eye fatigue and vision-related QOL (r=-.55, p<.001). It was found that the final factors affecting the vision-related QOL of middle-aged patients with dry eye syndrome were the severity of dry eye syndrome symptoms (β=-0.76, p<.001) and dry eye stress (β=-0.14, p=.048). The explanatory power of vision-related QOL in the participants was 56.0%. Conclusion: To develop indices that can objectively measure patients' subjective symptoms for improving their vision-related QOL is necessary.