• Korean Journal of Clinical Laboratory Science
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• v.53 no.4
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• pp.333-341
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• 2021

Benzodiazepines (BDZs) drugs act on the GABA_A receptor, function as nerve suppressors, and are used to treat anxiety, insomnia, and panic disorder. We analyzed the data of 30 individuals to determine any differences in the sleep-electroencephalogram findings among individuals varying in age, benzodiazepine use, and duration of benzodiazepine use. Comparisons between users and non-users of benzodiazepines, short-term and long-term users, older and younger users, and older short-term and older long-term users, were achieved using electroencephalographic findings obtained through polysomnography. The parameters evaluated included sleep latency, sleep efficiency, sleep-stage percentages, number of sleep spindles, and average frequency of sleep-spindle. The difference between benzodiazepine users and non-users was significant with respect to sleep-stage percentages and average frequency of sleep-spindle. Older and younger users differed significantly with respect to sleep efficiency and sleep-stage percentages, whereas significant difference for sleep efficiency was obtained between long-term and short-term users. Taken together, our results indicate that BDZ consumption suppresses slow-wave sleep and increases the frequency of sleep spindles.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.808-813
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• 2008

The study was to evaluate the air-conditioning of sleep algorithm. The algorithm was developed through the analysis of brain waves and MST, the experiments using air conditioner was performed in a apartment bedroom. Five female subjects were participated for the experiment. Eight hours of data collection a day was performed under different algorithm, case A, case B and case C. Physiological signals, EEG, ECG, EOG, and EMG, were obtained using polygraph and converted into digital signal. Then, subjects were asked to answer the questionnaire about their thermal sensation after experiment in bedroom. Sleep stages were classified, then TST, Sleep latency and Sleep efficiency were calculated for the three different air conditioner algorithm. As results, TST, Sleep efficiency, questionnaire showed the higher values for Case B algorism than that for other algorism. On the other hand, SWS latency was lower than for other conditions. Therefore, it was concluded that Case B of the algorithm was the best for comfortable and deep sleep.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1074-1086
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• 2015

We Relay-assisted cellular network architecture has been developed to cover cell-edge users and to improve capacity. However, the deployment of relay stations (RSs) in cellular networks may increase the total energy consumption. Though energy efficiency has become a major concern in cellular networks, little work has studied the energy efficiency of relay-assisted cellular networks by sleep scheduling. In this paper, a distributed base stations (BSs) sleep scheduling scheme in relay-assisted cellular networks is proposed. The goal is to maximize the energy efficiency under the spectral efficiency constraint. Firstly, whether the BSs should be sleeping or active is determined by the traffic profile. Then, the transmission powers of the active BSs are optimized within the game-theoretic framework, by using an interior-point method, so as to maximize the energy efficiency. Simulation results demonstrate that the effectiveness of the proposed scheme is superior to that turning on all the BSs without sleep scheduling.

• Journal of Korean Critical Care Nursing
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• v.1 no.1
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• pp.19-31
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• 2008

Purpose: This study was conducted to exam the effects of the Abbreviated Cognitive Behavioral Therapy(ACBT) on chronic insomnia. Methods: Study was one-group interrupted time series study that involved 13 adults(mean age=51.7, aged 25-77 years) with chronic primary insomnia who visited sleep disorder clinic of S Hospital from November 2004 to October 2005. The subjects received 2-session individual ACBT with 2 week-interval($1^{st}$: 1.5- 2hrs, $2^{nd}$: 20-30min). To measure the subjective insomnia severity and sleep patterns, 3 times of insomnia severity index and sleep logs were completed(before ACBT, after ACBT, and 3-month after ACBT). The main outcomes were subjective insomnia severity and sleep patterns(sleep onset latency, waking after sleep onset, and total sleep time, sleep efficiency). The data were analyzed with SPSS 10.0 version program by Friedman test, Wilcoxon signed rank test with Bonferroni correction. Results: There were statistically significant decrease in insomnia severity index, sleep onset latency, and waking after sleep onset, and increase total sleep time and sleep efficiency. Conclusion: ACBT was effective in reducing subjective insomnia severity and improving sleep patterns. Sleep improvement was better sustained over time with ACBT.

• Journal of Korean Biological Nursing Science
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• v.13 no.3
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• pp.211-219
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• 2011

Purpose: The study compared the rest-activity rhythm and sleep pattern of elderly with young group. Methods: The subjects were 22 over than 65 years old and 23 under 65 years old. An actigraph, sleep diary, Pittsburgh Sleep Quality Index and Insomnia Severity Index scale were used as measurement tools for this study. The data were analyzed with $x^2$, Lamda test, t-test and correlation with SPSS 15.0 program. Results: The elderly had lower curve than the young group in rest-activity rhythm on each time zone. In particular, the elderly group had lower rest-activity rhythm curve of 8, 9, 14, 18, 19, 20, 21, 22 and 23 time zone than those of young group. Sleep pattern had statistical difference in the total sleep time, PSQI and insomnia. Total sleep time of elderly had lower score and PSQI and Insomnia had higher score than young group. Age had correlation with rest-activity rhythm, sleep efficiency, PSQI and insomnia. Conclusion: Rest-activity rhythm of the elderly showed an increase in activity in the early morning because of earlier get up than the young group and an decrease in activity in the afternoon because of taking a nap at this time. Elderly sleep was that total sleep time increased but sleep efficiency decreased and insomnia intensified. This sleep pattern was related to age and rest-activity rhythm.

• Journal of Life Science
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• v.12 no.4
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• pp.375-382
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• 2002

The purpose of this experiment was to examine influence of acute exercise on nocturnal sleep which had been disrupted by caffeine(400mg$\times$3) thought the daytime. Six healthy young males aged 21.0$\times$0.2 yr with a history of low caffeine use. Subjects completed three conditions in a within-subject. At three conditions Sleep EEG were investigated: (1) nocturnal following quiet rest, (2) nocturnal sleep following the consumption of 1200mg of caffeine (3) nocturnal sleep following cycling at 60 min of 60% V $O_{2peak}$ with 1200mg of caffeine consumption. Sleep data were calculated for REM sleep, REM latency, sleep onset latency, sleep efficiency, sleep stages, SWS. Those data were analyzed using repeated-measures ANOVA of change scores. A main effect to, drug(caffeine) indicated that caffeine elicited sleep disturbance that is, TST and sleep onset latency increase and sleep efficiency and stage 4 decrease. The effects of exercise on sleep following caffeine intake generally improve sleep that is, stage 2, 3 and SWS increase and sleep onset latency decrease. A condition effect for sleep indicated sleep improvement after exercise Therefore The data supported a restorative theory of slow-wave sleep and suggest that acute exercise may be useful in promoting sleep and reducing sleep disturbance elevated by a high dose of caffeine.

• Sleep Medicine and Psychophysiology
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• v.18 no.2
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• pp.67-71
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• 2011

Schizophrenia is a chronic, currently incurable, and devastating syndrome. Although sleep disturbances are not primary symptoms of schizophrenia, they are important aspects of schizophrenia. Difficulties initiating or maintaining sleep are frequently encountered in patients with schizophrenia. Many schizophrenics report low subjective sleep quality. Measured by polysomnography, increased sleep latency as well as reduced total sleep time, sleep efficiency, slow wave sleep, and rapid eye movement sleep latency (REM latency), are found in most patients with schizophrenia and appear to be an important aspect of the pathophysiology of this disorder. Some literatures suggest that worsening sleep quality precedes schizophrenic exacerbations. Co-morbid sleep disorders such as obstructive sleep apnea (OSA) and restless legs syndrome (RLS), and sleep-disrupting behaviors associated with schizophrenia may lead to sleep disturbances. Clinicians should screen the patient with sleep complaints for primary sleep disorders like OSA and RLS, and carefully evaluate sleep hygiene behaviors of all patients with schizophrenia who complain of sleep disturbances.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.842-846
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• 2016

This paper presents a DC-DC buck converter which uses a sleep control to improve the power efficiency in a few mW light load condition. The sleep control turns off analog controller building blocks to reduce the static power losses during the off-duty period of pulse width modulation. For verification, a buck converter has been implemented in a $0.18{\mu}m$ CMOS process. The power efficiency has been improved from 76.7% to 82.5% with a 1.2 mW load. The maximum power efficiency is 95% with a 9 mW load.

• Journal of Korean Biological Nursing Science
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• v.16 no.4
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• pp.309-317
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• 2014

Purpose: The purpose of this study was to understand sleep circadian rhythm and sleep quality between normal-weight and obese group according to Body Mass Index to develop education and nursing intervention programs for the obese. Methods: This study involved 186 subjects who visited at S hospital obesity clinic, K province. They were divided into 2 groups: normal-weight group 91 and obese group 95. Data were collected from October 18th to November 12th in 2013. Data were analyzed with frequency, percentage, ${\chi}^2$-test, Mann-Whitney U test, ANCOVA, t-test and ANOVA with using SPSS version 20.0. Results: The results showed that morning type 1.1%, middle type 91.2% and evening type 7.7% of sleep circadian rhythm in normal-weight group and middle type 92.6% and evening type 7.4% of sleep circadian rhythm in obese group. There were statistically significant results on sleep quality with covariance sex and stress, sleep duration, habitual sleep efficiency and sleep disturbance between normal-weight and obese group. There were statistically significant results on sleep quality, sleep duration, habitual sleep efficiency and sleep disturbance in middle type of sleep circadian rhythm between normal-weight and obese group. Conclusion: Therefore, it is necessary to consider subject's sleep pattern to develop education and nursing intervention programs for the obese.

• Journal of Korean Biological Nursing Science
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• v.18 no.4
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• pp.203-212
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• 2016

Purpose: The purpose of this study was to identify the sleep patterns of nursing students using self-report questionnaire and physiologic measurement, to examine the factors influencing sleep patterns in based on Spielman's model. Methods: Participants were 119 nursing students who were in the clinical practice period. Self-report questionnaires and actigraphy were used to collect the data. Data were analyzed using descriptive statistics, correlation and regression by the SPSS/WIN 21.0 programs. Results: When sleep was measured by self-report questionnaire, 84 students (70.6%) showed poor sleep quality. The mean sleep efficiency was 82.6%, and 67 students(56.3%) showed low sleep efficiency (less than 85.0%). The factors affecting subjective sleep pattern measured by KMLSEQ were circadian sleep type (${\beta}=.28$, ${\rho}=.003$) and alcohol (${\beta}=.20$, ${\rho}=.031$). The factors affecting total sleep time were sedentary behavior (${\beta}=-.27$, ${\rho}=.003$) and daytime sleepiness (${\beta}=-.33$, ${\rho}$<.001). Conclusion: Many nursing students in their clinical practice period expressed sleep disturbance. Factors affecting the perceived sleep measured by the self-report questionnaire and objective sleep evaluated by physiologic measures were different. The evening type of students perceived poor sleep quality, however, sedentary life style and daytime sleepiness resulted in short sleep time. Therefore, more studies measuring the objective sleep characteristics are needed using subjective and objective characteristics.