• Sleep Medicine and Psychophysiology
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• v.6 no.1
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• pp.68-75
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• 1999

Objectives: We intended to observe changes in sleep patterns and mood states of night-shift workers following light exposure. We also estimated the degree of tolerance of light exposure. By studying these, we investigated the possibility of applying light therapy to night-shift workers for improving their adaptation. Methods: Twelve night-shift nurses working at Yong-In Mental Hospital volunteered to participate in this study. The study consisted of 3 parts: 1) night-shift control study; 2) light exposure study; 3) day-shift control study. All the nurses accomplished 3 parts of the study, each of which continued for 3 days, except one nurse who did not participate in day-shift control study. During light exposure study, nurses were exposed to bright light for 4 hours from 1AM to 5AM. Sleep patterns were evaluated with wrist actigraphy and automatic sleep analysis program. Mood states and side effects of light exposure were assessed with self-report scales. Results: Sleep period time, total sleep time, and sleep efficiency were increased following light exposure compared with night-shift control study. Light exposure study showed no difference from day-shift control study in above-mentioned sleep parameters. Daily fluctuation of sleep efficiency was less prominent during light exposure study than during night-shift control study. During light exposure study, the subjects felt more elated and energetic in the evening after daytime sleep than during night-shift control study. None of the subjects complained of severe side effects related to light exposure on the third day of light exposure. Tolerance of side effects was noted to develop with the repetition of light exposure. Conclusion: Light exposure improved the daytime sleep of night-shift workers to the level of normal nighttime sleep, making the subjects more elated and energetic. Side effects of light exposure were found to be tolerable. Light exposure seems to be safely applicable to night-shift workers for their adaptation.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.86.2-86.2
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• 2010

태양광발전 시스템에 있어 일사량의 높고 낮음은 경제성 평가를 결정하는 주요인자로 작용하며 일사량은 지역적, 지형적 환경 조건의 차이에 따라 달리 나타난다. 본 연구에서는 주암 저수지 수면에 설치된 수면태양광 일사량 계측자료와 지상에서의 주암댐 관리단 옥상에 설치된 일사량 계측자료를 비교하여 분석한 결과 수면태양광의 일사량이 지상에서의 일사량 보다 약간 상회하는 패턴을 보이며 풍속, 기온 등 기타 데이터 분석 시 수면이 태양광발전에 있어 지상보다 더 유리하다는 점을 검증 할 수 있었다. 또한 취득한 데이터를 가지고 경제성 분석 프로그램을 사용하여 분석한 결과 지상보다 수면태양광이 더 경제성 있다는 결과를 얻을 수 있었다.

• The Journal of Korean Academy of Sensory Integration
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• v.15 no.1
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• pp.33-45
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• 2017

Objective : This study was to investigate the relationship between sensory processing patterns and sleep quality for poor sleepers enrolled in universities. Methods : The participants are 191 students, aged 18 to 25, at the 6 universities located in Busan, Daegu, and other Gyeongsang Provinces. These participants completed the Korean version of Adolescent/Adults Sensory Profile (AASP) and the Pittsburgh Sleep Quality Index (PSQI). Results : The group with lower sleep quality of this study participants suggested low but positive correlation with sleep disturbance which is one of sleep quality components of the PSQI. Low sensory registration suggested high positive correlation and Sensory sensitivity suggested low positive correlation with daytime dysfunction. Conclusion : We identified that sensory processing patterns and sleep quality may influence each other and sleep quality can be more significantly influenced by specific sensory processing pattern. More studies requires on sleep quality and sensory processing patterns in children, adults, and elders.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.311-316
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• 2020

The purpose of this study is to compare fatigue, stress and quality of sleep between good sleep quality and poor sleep quality. Fatigue, stress and quality of sleep were assessed using three questionnaires; fatigue severity scale(FSS), Perceived stress scale(PSS), and Pittsburgh sleep quality index(PSQL). As a result of the study, the higher stress(22.2 vs. 19.0, p=.000) and poorer quality of sleep(11.2 vs. 5.7, p=.000) were observed between good sleep quality and poor sleep quality groups. Our finding show that time of going to bed and stress level influenced quality of sleep.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.406-406
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• 2020

본 연구에서는 하도에 대한 하천환경성을 평가하기 위해 관련연구 및 환경관련사업 분석을 통해 환경기능을 대표할 수 있는 환경생태수심, 수면폭-하폭비, 횡단구조물, 수질 등 4가지 요소를 결정요소로 선정하였다. 각각의 결정요소에 대해서 관련지침, 연구, 설계기준 등을 토대로 평가 기준을 설정하였다. 이 중 수면폭-하폭비에 대한 정량적 기준이 명확하지 않아 자연하천과 도시하천을 대상으로 환경생태유량 적용을 통한 수리분석을 실시하였으며 분석 결과를 통해 평가 기준을 결정하였다. 자연하천으로는 자연성을 비교적 잘 유지하고 있는 평창강, 영강, 남강을 포함한 8개 하천, 도시하천은 안양천, 중랑천을 포함한 24개 하천을 대상으로 하였다. 분석결과 자연하천은 도시하천에 비해 수면폭-하폭비가 크고, 분포가 고른 것으로 나타났으며 도시하천은 수면폭-하폭비가 자연하천과 비교하여 작은 구간이 많으며 각종 하천사업으로 인해 분포가 고르게 분포하지 못하는 것으로 나타났다. 또한, 도시하천 중 복개구간을 포함하는 하천은 인위적인 하폭 및 수면폭 형성으로 인해 수면폭-하폭비가 큰 것으로 분석되었다. 분석결과를 종합하여 하도의 환경성 평가를 위한 수면폭-하폭비 기준은 0.33으로 결정하였으며 이를 특정하천에 활용할 경우, 측점별 수면폭-하폭비를 산정하고, 하천 전체 연장 대비 해당 값에 만족하는 구간연장을 점수화 하여 수면폭-하폭비 평가 결과로 활용하도록 하였다. 본 연구의 성과는 하천환경성을 정량적으로 평가함으로써 향후 하도계획 수립 시 하천환경성 증진을 위한 기반자료로 활용될 수 있을 것으로 기대된다.

• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.11-20
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• 2008

IEEE 802.16e has adopted sleep mode to minimize energy consumption of mobile nodes with high speed mobility. If the Base Station (BS) has no data to be sent to a Mobile Subscriber Station (MSS) at the instant of ending sleep window of the MSS, the MSS increases its sleep window interval by double until the window interval reaches to the maximum sleep window interval. Thus, during the operation of sleep mode, MSS repeatedly performs switch on/off action until there exist frames to be received from BS. The switch on/off operation significantly consumes energy of MSS. To effectively deal with the energy of the MSS, this paper proposes an algorithm which decides the minimum sleep window interval that will be used in next sleep mode based on the current sleep window interval. We evaluate the performance of IEEE 802.16e sleep mode algorithm and our proposed algorithm in terms of energy consumption and blocking probability. Compared with the current sleep mode algorithm used in IEEE 802.16e, the proposed algorithm decreases the energy consumption by about 30% without increasing blocking probability.

• Journal of Oral Medicine and Pain
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• v.31 no.1
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• pp.91-99
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• 2006

This study was performed to investigate about sleep quality and orofacial pain pattern between experimental and control group. 101 subjects with temporomandibular disorders without any psychologic and neurologic problem were selected from the patients presented to Wonkwang University dental hospital. Routine clinical examination for TMD was carried out, especially for the frequency of headache and the craniocervical muscles were also done by the author in the first visit. All the subjects filled out the questionnaires, that was, for the evaluation of sleep quality using Pittsburgh sleep quality index(PSQI), and for the analysis of behavioral pain scale questionnaires. Data obtained were statistically processed by the SPSS Windows program and the results of this study were as follows: 1. Subjective sleep index, sleep latency, sleep disturbance, global score in control group were significantly lower than 2. Subjective sleep index, sleep disturbance, global score in subject with headache were significantly lower than subject without headache(P<0.05). 3. Medicine taker have sleeping drug. Caffeine drinkers was significantly higher in daytime dysfunction, global score than no drinker. 4. It have more frequent head and neck pain, pain spreading, daily life difficult in poor sleeper than good sleeper.

• Sleep Medicine and Psychophysiology
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• v.8 no.2
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• pp.129-137
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• 2001

Objectives: The purpose of this study is to investigate the effects of 38-hour sleep deprivation on fine motor performance. The Motor Performance Series (MPS) in the Vienna Test System (computerized neurocognitive function tests) was used in this study. Methods: Twenty four subjects participated in this study. Subjects had no past history of psychiatric disorders and physical illness. Subjects had normal sleep-waking cycle without current sleep disturbances and were all right-handed (Annett's Hand Preference Questionnaire: above +9 points). To minimize the learning effects, familiarization with the Vienna Test System was performed one day before the study. Subjects were to get up at 6:00 in the morning after getting enough sleep according to his or her usual sleep-wake cycle. After awakening, subjects remained awake for 38 hours under continuous surveillance. During two consecutive study days, the subjects tested MPS at 7 AM and 7 PM each day, which means the MPS was done four times in total. During the experiment, anything that could affect the subjects' sleep such as coffee, tea, alcohol, a nap, tiring sports, and all medications were prohibited. Results: In MPS, the fine motor functions of both hands decreased after 38 hours of sleep deprivation. The decrement in motor performance was prominent in the dominant right hand. In the right hand, the total number of tapping was reduced (p<.005), and the number of misses (p<.05) and the length of misses (p<.05) of line tracking, the total length of inserting a short pin (p<.01), the total length of inserting a long pin (p<.05), and the number of misses in aiming (p<.05) increased. Such performance decrement was distinct in the morning sessions. Conclusions: These results suggest that fine motor performance decrement during sleep deprivation is predominant in the right hand, which exerts maximal motor function. The finding of decrement in motor function in tapping during sleep deprivation also suggested that the time required for exhaustion of muscles is shortened during sleep deprivation. More deterioration of motor performance was shown in the morning, which could be explained as circadian rhythm effects.

• Sleep Medicine and Psychophysiology
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• v.28 no.1
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• pp.27-33
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• 2021

Objectives: The purpose of this study is to investigate the difference in the effects of eye-mask and light-off on sleep status according to a commercial fitness tracker and a sleep diary of psychiatric in-patients in correctional facilities where nocturnal light is compulsory. Methods: This study was conducted over 3 consecutive nights. In-patients of the National Forensic Psychiatric Hospital (n = 29) were assigned random subject numbers and slept as usual in the light-on condition on the first night. The subjects slept with eye-masks in the light-on condition on another night and without an eye-mask in the light-off condition on the other night. Subjects were asked to sleep wearing a commercial fitness tracker and to keep a sleep diary. The order of these changes in bedroom lighting condition on the second and third nights was assigned randomly to participants. Results: In comparison of the sleep variables between the light-on condition and the eye-mask condition, the Wakefullness After Sleep Onset (WASO) was shorter and sleep satisfaction was higher in the latter.(respectively, Z = 3.66, p < 0.017 ; Z = 2.69, p < 0.017) In comparison of the sleep variables between the light-on and light-off conditions, the WASO was shorter and sleep efficiency and sleep satisfaction were higher in the latter (respectively, Z = 2.40, p < 0.017 ; Z = 3.02, p < 0.017 ; Z = 3.88, p < 0.017). However, there were no differences in the sleep variables between the eye-mask condition and the light-off condition. Conclusion: Subjective improvements in sleep variables were noted in sleep diaries of institutionalized psychiatric patients under either the 'eye-mask' or 'light-off' condition. However, there were no significant differences between the 'eye-mask' and 'light-off' conditions. Therefore, we suggest that psychiatric patients in correctional facilities use eye-masks when sleeping.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.116-126
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• 2020

This study analyzed the effects of auricular acupressure on improving sleep disorders of the elderly. The data was collected from domestic and foreign databases. The keywords were 'auricular,' 'sleep,' 'insomnia, and so on. RoB and RoBANS were used to evaluate the risk of bias in the selected literature. Meta-analysis was performed using RevMan 5.3. Seven of 386 studies were selected. Regarding the sleep score, those studies with an intervention period of less than four weeks showed WMD of 25.66 (95% CI; 20.18 to 31.14), which was significantly higher than that of the control group. Similarly, the studies with an intervention period longer than four weeks had significantly higher WMD than that of the control group, and the former exhibited WMD of 8.59 (95% CI: 6.26 to 10.92). In contrast, sleep satisfaction was significantly higher in the studies with a maintenance period of three days or less, which resulted in SMD of 13.37 (95% CI: 5.29 to 21.45). The score in the studies with a maintenance period longer than four days was significantly higher than that of the control group with SMD of 2.27 (95% CI: 1.82 to 2.72). Auricular acupressure was effective in alleviating sleep disorders among the elderly in terms of both sleep quality and sleep satisfaction.