• KIPS Transactions on Computer and Communication Systems
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• v.7 no.7
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• pp.175-182
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• 2018

The purpose of this study is to analyze the effect of sleep environment on individual sleep and to calculate optimal sleep environment. The input and output data sets are selected and the optimized sleep environment information is calculated using the neuro-fuzzy technique. Provides optimal sleep environment considering sleep duration. The arousal ratio calculated by the proposed method is 12%, which is at least 5% lower than the previous studies.

• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.127-129
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• 2013

문풀은 해저케이블선, 해저탐사선, 생산용 부선, 드릴쉽과 같은 여러 종류의 선박에 설비되어 해상에서 각 작업에 필요한 장비의 진수 및 작업공간으로 활용되고 있다. 이러한 문풀내 자유수면의 유동은 정수중 부유체의 이동으로 인한 것과 작업중인 부유체에 작용하는 입사파에 의해 기인하는 것으로 알려져 있다. 본 연구에서는 입사파에 의한 문풀내 유동 특성을 분석하기 위하여 다양한 해상상태, 즉 서로 다른 파고와 파장에서의 자유수면의 변화와 문풀에 작용하는 유체력 계산을 CFD에 의하여 수행하였다. 수치 계산 결과 문풀내 수면 상승 및 유체력은 파고 및 파장에 의해 크게 영향을 받고 이것은 보오텍스와 같은 비선형 현상에 의한 것임을 확인할 수 있었다.

• Sleep Medicine and Psychophysiology
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• v.1 no.2
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• pp.163-171
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• 1994

Objectives: Symptoms of sleep apnea consisted of insomnia, excessive sleepiness during daytime, impaired cognitive functions and emotional disturbances. It was not so well known how these symptoms are correlated with various parameters of sleep and respiration, and what kind of psychophysiological processes are involved in development of these symptoms. Methods: In sixty patients with sleep apnea, sleep and respiration were studied by polysomnography of one night, also symptoms of sleep apnea were evaluated with the scales of insomnia, daytime sleepiness, emotional disturbance and cognitive impairment We studied correlations between apnea symptoms, and various parameters of sleep and respiration such as sleep efficiency, number severity of apnea, $O_2$ desaturation and number of snoring. Results: The result showing significant correlations are as follows. The patients with better sleep in insomnia scale showed more number of apnea, particularly more central type, and much more snoring in stage 3 sleep and mild desaturation of $O_2$. Excessive sleepiness during daytime correlated significantly with stage 1 sleep and its snoring, but correlated negatively with stage 2 sleep. However, no significant correlation was found with degree of $O_2$ desaturation. Emotional disturbance was more apparent in the patients with severe $O_2$ desaturation and smaller amounts of stage 4 sleep. Cognitive function was more impaired in cases of more REM sleep and less apnea. Conclusions: Symptoms of sleep apnea may occur through different causes and processes. The evaluation of apnea symptoms may be helpful to understand in some degree the condition of sleep and respiration during sleep in clinical setting.

• Journal of Korea Ship Safrty Technology Authority
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• s.33
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• pp.12-31
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• 2012

수치 계산으로 고속 활주선의 저항 성능을 평가하기 위해서는 활주 상태에서의 항주자세 예측이 무엇보다도 중요하다고 할 수 있다. 항주자세의 변화가 큰 고속 활주선의 경우에는 활주 자세에 따라 선저 바닥면에서 나타나는 압력 변화에 의한 동적 부양력 변화가 크므로 단순히 정지 중 흘수를 기준으로 계산되어진 유체력으로 항주자세를 예측하기 보다는 자세 변화에 따른 동적 부양력의 변화와 이에 의한 자세 변화를 반복 계산을 통해 수렴시키는 것이 요구되어진다. 본 연구에서는 선형화된 자유수면 조건의 포텐셜 수치 계산으로 유체 동압력인 부양력을 계산해내고 이를 유체 정역학적 힘으로 간주하여 부력과 선체중량과의 힘과 트림 모멘트 평형 관계를 만족시키는 방법으로 반복적인 계산을 통해 수렴된 활주 자세를 얻어내었다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.11a
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• pp.23-27
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• 1999

하절기 실내 온도의 변화에 따른 수면 후의 감성상태를 비교하고자 5명의 여성 피험자로 하여금 3 수준(22$^{\circ}C$, 26$^{\circ}C$, 3$0^{\circ}C$)의 실내온도에서 8시간 정도의 수면을 하게 한 다음 수면 쾌적성에 관한 설문을 실시하였다. 설문분석 결과, 22$^{\circ}C$와 26$^{\circ}C$도 조건에서의 수면이 3$0^{\circ}C$도 조건에서보다 온도와 습도가 쾌적한 것으로 평가되었으며, 전반적으로 쾌적한 수면으로 평가되었다. 수면 후 집중력이나 식욕과 관련된 질문에서도 26$^{\circ}C$도 조건이 가장 쾌적한 것으로 나타났다.

• Journal of Digital Convergence
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• v.17 no.4
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• pp.335-344
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• 2019

This study aimed to identify the effect of stress, smartphone addiction, Social support, and physiological index on quality of sleep (PSQI) and to investigate the affecting factors according to sex in highschool students. The data were collected from 210 subjects from February 6 to 16, 2018 using a structured self-report questionnaires and analyzed using descriptive statistics, t-test, ANOVA, and multiple regression with SPSS WIN Version 24.0. The quality of sleep was lower in female students than in male students. In multiple regression analysis, Awake time, School grades stress were significant predictors and explained 29.6% of quality of sleep for male students. In female students, Smart phone start age, School grades stress, Disability of daily living and Appraisal social support were significant predictors and explained 24.3% of quality of sleep. Therefore, it is expected to be used as basic data for the development of intervention programs that can solve the factors affecting the quality of sleep of adolescents, thereby helping the healthy development of youth.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.3
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• pp.198-204
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• 2014

Ships sailing the seas encounter air resistance. The air resistance depends on the shape of the above-water hull, the ship speed, the wind speed and wind direction. The experimental or statistical methods which are used to predict the air resistance are one of the essential procedures of the calculation of the towing force of the disabled ships. This paper shows simplified air resistance prediction method using the variables of the projected area of the above-water hull, the speed of the ship, the wind speed and its direction. These methods have been applied to the existing computer program which had been set up to predict the towing force of the disabled ships.

• The Journal of Korean society of community based occupational therapy
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• v.8 no.3
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• pp.69-76
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• 2018

Objective : The study was to investigate the neurophysiological approach to the effect of complex exercise on memory, one of brain functions, and the degree of sleep disorder using experimental animals with sleep disorders. Methods : This study carried out a complex exercise that designed in an animal laboratory for 4 days to 16 sleep - disordered model rats. After the exercise, brain function was confirmed with the changes of BDNF in the hippocampus and the change of sleep level was confirmed with the concentration of melatonin in the blood. Results : First, the effect of the complex exercise program on brain function was significantly increased in the experimental group(p<0.01). Second, the effect of complex exercise program on sleep disturbance was significantly increased in the experimental group and control group(p<0.01)(p<0.05). Conclusion : The rate of increase of the elderly in the community is rapidly increasing, and the sleep disorder of the elderly can affect the quality of life of these elderly people. Secondary memory impairment due to sleep disturbances can also be a problem. Although there are many ways to improve sleep disturbance, it has been scientifically proven through experimental animals that sleep and memory can be improved with complex exercise that is not economically, spatially burdensome.

• Sleep Medicine and Psychophysiology
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• v.22 no.2
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• pp.53-56
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• 2015

Good sleepers tend to more resilient than poor sleepers. As sleep and resilience may have a bidirectional relationship, it is important to explore the relationship between healthy sleep and resilience. Objectively and subjectively measured sleep quality showed positive association with resiliency. In one study, more resilient adolescents had higher sleep efficiency, less light sleep, more slow-wave sleep, and a smaller number of awakenings after sleep onset. Circadian typology, jetlag and circadian misalignment may be associated with the capacity to deal with adversity. Eveningness, exposure to chronic jetlag and circadian misalignment might be risk factors for development of psychological problems and mental disorders. Additional studies are needed to evaluate whether promoting healthy sleep behaviors results in increased resilience.