• Science of Emotion and Sensibility
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• v.14 no.3
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• pp.459-466
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• 2011

Sleep diseases such as snoring and sleep apnea are physically, mentally harmful and results serious health problems. Snoring, known as breathing noise, is caused by coupled oscillation of the airway when the air passes through the trachea, and sleep apnea is caused by upper airway blockage. In order to solve these problems, many attempts have been made to detect the snoring during sleep and alleviate it. In this study, a new sensing system and analysis algorithm were developed in order to detect snoring sounds correctly under various sleep environments. Two polyvinylidene fluoride (PVDF) vibration sensors were used inside the pillow. The first PVDF sensor detects vibration transmitted through skull caused by snoring. And the second PVDF sensor detects both snoring sounds and ambient noises. The signals of two sensors were acquired through the designed analog circuits, and analyzed for snoring detection. Ten volunteers were participated for the experiment under five different conditions. Data from two PVDF sensors were processed by the established analysis algorithm, and snoring sounds were compared to noises. The results indicated that the energy of snoring is 70% bigger than that of ambient noise, which proves effectiveness of sensing system and analysis algorithm. Further study would be continued for more wide clinical studies with various environment noises. Based on this study, development of anti-snore pillow and sleep monitoring system for comfort sleep could be developed.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.2
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• pp.198-210
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• 1999

This study is to investigate sleep patterns of rheumatoid arthritis patients through a survey research. The subjects for this study were 97 patients registered in Hanyang University Hospital Rheumatoid Arthritis Center, and the period of data collection was from July 15, 1998 to August 30, 1998. The research instruments used in this study were the measures of sleep, pain, and fatigue, and SPSSWIN 8.0 Program was used for data analysis. The research results are as follows ; The patients went to bed between 11 and 12 p.m., but many of them found difficulty in falling asleep within 5 minutes. They woke up quite early at around 4 to 6 o'clock in the morning and remained in bed about 1 hour. Only 39 percent of the subjects reported satisfaction with their sleep. Fifty six percent of the subjects took a nap, generally did in the afternoon and 22.7 percent of them napped for half an hour. They suffered sleep disturbance, but their sleep environments were calm and comfortable, and they turn off the light when they went to sleep. As for the quality of sleep, over 50 percent of the subjects reported not being able to sleep deeply, 30 percent of the subjects woke up frequently during sleep, 60 percent experienced frequent arousal after sleep onset. Over 90 subjects slept for 6 to 8 hours. This shows that even though they had rheumatoid arthritis, the patients remained in bed for a sufficient period of time. They also reported waking up or turning frequently during sleep. The sense of fatigue from sleep disturbance scored a relatively high 35.84 points on average against the possible score of 64 points. Behavior for sleep promotion was very active. Sleep disturbance occurred in proportion to the sense of fatigue and pain, and was negatively correlated with quality of sleep. The pain had positive correlations with the illness duration, sleep disturbance and had a negative correlation with the quality of sleep.

• International Journal of Highway Engineering
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• v.7 no.2 s.24
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• pp.13-22
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• 2005

Using recycled aggregate from demolished concrete structures provides a peat opportunity fur conserving natural resources. In many parts of world, virgin aggregate deposits have been depleted, and transporting aggregates over long distances can be much more expensive than using a low-cost recycled aggregate. In Korea, about 7-million tons of concrete occurs annually, out of this, about 2-3 million tons are available for recycling. This study is to present the method of utilizing the recycled aggregate. The recycled aggregate concretes were made for compressive strength test, flexural strength test and fatigue test using w/c of 40, 50 and 60%. The replacing rates of recycled aggregate to virgin aggregate were 0, 25 and 50%. The purpose of this study is to compare the fatigue lift of recycled aggregate concrete with that of virgin aggregate concrete. It was shown that the fatigue life of recycled concrete was function of recycled aggregate replacement ratio and water cement ratio.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.2164-2172
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• 2009

The purpose of the present study was intended to assess fatigue symptoms of nurses working at special part(operating room, intensive care unit, emergency room) and ward in general hospitals, and to reveal its related factors. The self-administered questionnaires were given to 393 nurses employed in 3 participating hospitals located in Daejeon City. As a results, the special part workers had higher scores of fatigue symptoms than the ward workers. Multiple stepwise analysis revealed that the factors of influence on fatigue symptoms in the special part workers included subjective health status, age and job satisfaction, and in the ward workers, the factors of influence on fatigue symptoms included subjective health status, sleep hour, shift work and job satisfaction. In conclusion, the fatigue symptoms were higher in the special part workers than the ward workers, and its related factors were different from two worker groups.

• 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.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.47-52
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• 2005

Obstructive Sleep Apnea (OSA) is a representative symptom of sleep disorder caused by the obstruction of upper airway. Because OSA causes not only excessive daytime sleepiness and fatigue, hypertension and arrhythmia but also cardiac arrest and sudden death during sleep in the severe case, it is very important to detect the occurrence and the frequency of OSA. OSA is usually diagnosed through the laboratory-based Polysomnography (PSG) which is uncomfortable and expensive. Therefore researches to improve the disadvantages of PSG are needed and studies for the detection of OSA using only one or two parameters are being made as alternatives to PSG. In this paper, we developed an algorithm for the detection of OSA based on Heart Rate Variability (HRV). The proposed method is applied to the ECG data sets provided from PhysioNet which consist of learning set and training set. We extracted features for the detection of OSA such as average and standard deviation of 1 minute R-R interval, power spectrum of R-R interval and S-peak amplitude from data sets. These features are applied to the input of neural network. As a result, we obtained sensitivity of $89.66\%$ and specificity of $95.25\%$. It shows that the features suggested in this study are useful to detect OSA.

• Journal of muscle and joint health
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• v.6 no.1
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• pp.136-152
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• 1999

The purposes of this study were to identify the prevalence of fatigue. and factors influencing fatigue in women with rheumatoid arthritis. The subjects were 124 patients with rheumatoid arthritis. Most of all patients felt fatigue and mean score measured by Multidimensional Assessment of Fatigue was relatirely high. Fatigue was positively correlated with pain intensity, the number of pain sites, functional disability, depression. and sleep quality. A hierachical regression model was used to determine the variance which accounts for fatigue. Pain intensity, depression. sleep quality accounted for fatigue significantly. This finding indicates that pain influences fatigue through depression and sleep quality ; depression through sleep quality. The causative factors could be identified by further study of structural eqation model.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.2
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• pp.63-71
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• 2005

There is a concern in the aviation community that pilot schedules can lead to fatigue and increased chance of an aviation accident. Yet despite this concern, there is little empirical studies showing the relationship between pilot fatigue and commercial aviation accidents. At this point of view, countering fatigue is a challenging proposition in complex aviation operations. However, with appropriate planning, many strategies can contribute to pilot alertness and flight safety. With proper education program, sustaining a physiological fit, a right knowledge about pilot fatigue can design a safety operations. On this study, I inquire into the ways of enhancing pilot's efficiency from fatigue.

• 건강소식
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• v.38 no.8
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• pp.24-25
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• 2014

국민건강보험공단에 따르면, 수면 장애를 앓고 있는 사람이 지난 2008년 22만 8,000명에서 2012년 35만 7,000명으로 5년 사이에 약 13만명이 늘었다. 하루 이틀 잠을 설친다고 큰 병이 나는 건 아니나, 당장 피로와 두통을 느끼고 판단력 등 인지능력이 떨어지기 쉽다. 또 매번 밤잠을 설치면 매사에 의욕이 없고, 면역기능이 떨어져 병에 걸릴 확률도 높다. 당뇨나 심혈관질환, 뇌졸중 발생 위험이 폭발적으로 증가하게 된다. '짐이 보약'이라는 얘기를 허투루 들을 수 없는 이유다. 행복하고 개운한 굿~잠, 방법이 없을까.

• Sleep Medicine and Psychophysiology
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• v.25 no.2
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• pp.58-67
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• 2018

Objectives: The purpose of this pilot study was to examine the effects of a mindfulness-based Body-Mind Intervention Program using marine resources on the improvement of quality of sleep, mood symptoms, and cognitive function in Korean female emotional labor workers. Methods: Twelve female workers who experienced excess emotional labor participated at the training camp program for five days in Danghangpo-ocean park, Goseung-gun, Gyeongnam Province in South Korea. Participant sleep quality, mood symptoms, and cognitive functioning before, after, and 1.5 months later were evaluated and analyzed. Results: After participating in the marine resource program, participants reported significantly decreased sleep latency. Global sleep quality, cognitive functions (attention, flexibility, and inhibition control), and mood states, including depression, tension, anger, fatigue, were also improved. These effects were generally maintained after 1. 5 months (PSQI t = 2.63, p = 0.02 ; HAM-D t = 5.92, p < 0.001). Conclusion: A Body-Mind Intervention Program using marine resources was effective in relaxing emotion-related tension and improving cognitive function. To advance this pilot study, it is necessary to carry out further research to investigate the use of marine resources in mental health interventions.