• Journal of Life Science
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• v.28 no.8
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• pp.985-991
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• 2018

Biological clocks are the basis of temporal control of metabolism and behavior. These clocks are characterized by autonomous free-running oscillation and temperature compensation and are found in animals, plants, and microorganisms. To date, various biological clocks have been reported. These include clocks governing hibernation, sleep/wake, heartbeat, and courtship song. These clocks can be differentiated by the period of rhythms, for example, infradian rhythms (> 24-hr period), circadian rhythms (24-hr period), and ultradian rhythms (< 24-hr period). In yeast (Saccharomyces cerevisiae), at least five different autonomous oscillations have been reported; (1) glycolytic oscillations (T = 1~30 min), (2) cell cycle-dependent oscillations (T = 2~16 hr), (3) ultradian metabolic oscillations (T = 15~50 min), (4) yeast colony oscillations (T = a few hours), and (5) circadian oscillations (T = 24 hr). In this review, we discuss studies on oscillators, pacemakers, and synchronizers, in addition to the application of biological clocks, to demonstrate the nature of autonomous oscillations, especially ultradian metabolic oscillations of S. cerevisiae.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.165-171
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• 2011

A Consider the dead man's switch installed in each and every locomotive cab, which support operational safety on railways around the world. The concept is very simple - every 150 to 180 seconds an illuminated push-button demands to be acknowledged so as to know that the Train Driver is alive and active. In the absence of a response over a period of minutes, the vigilance control will automatically apply the train brakes and bring the train to a stand. If we multiply the resetting of the vigilance control 60 times per hour by a 10-hour shift it equals 600 presses of the button during the shift that a Train Driver must pay attention to and acknowledge. This adds a fair bit of pressure on the train driver's job, particularly when he/she is driving through stations, with passengers moving about on platforms in an environment of complex signaling arrangements - all the while looking out for restricting signals. From this perspective, the Vigilance System's demand to be acknowledged every 150/180 seconds is disturbing and can unnecessarily take a driver's attention away from what is happening outside the confines of the cab. A much more dramatic situation can happen when a train driver is driving hour after hour at night when, by Mother's Nature request - people need to sleep. Experience and research shows that the the dead man's switch can be pressed by train driver in a state of deep relaxation and 'micro-sleep'. The vigilance control system which is applied to reduce the drive load considering bio-response multiple unit train is proposed.

• Research in Community and Public Health Nursing
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• v.16 no.3
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• pp.289-299
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• 2005

Purpose: This study was carried out to identify premenstrual discomforts and coping patterns and their effects. Method: The participants of this study were 297 female university students in C area. The Menstrual Discomfort Questionaire (MDQ) and coping method lists were used as measurement tools. Results: There were significant differences premenstrual discomforts according to age (F=5.76, p=.003) and according to health condition (F=3.43, p=.034). The mean scores of the sub-categorical factors of premenstrual discomfort were 2.35 points for pain, 2.29 for instability and 2.25 for water retention. The worst symptoms among the subcategories of premenstrual discomfort were as follows: backache (M=2.68) in the pain subcategory, irritability (M=2.53) in the instability subcategory and swelling(M=2.40) in the water retention subcategory. Their common coping patterns were 'coping according to menstrual period', 'active behavioral coping' and 'evasional coping'. Frequently used coping methods were 'taking a rest and sleep (99.3%)' and 'taking a warm shower (86.2%)'. Effective coping methods were 'taking a rest and sleep (89.5%)' and 'taking a warm shower (87.1%)'. Conclusion: Most participants have their own coping pattern. Some methods were very effective to PMS but some were not effective to PMS. To manage PMS, effective coping methods should be encouraged for female university students. To keep up with effective coping, education and counseling should be continued. It is considered necessary to make the same research with a larger number of samples and more specified assessment.

• The Korean Journal of Pharmacology
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• v.15 no.1_2 s.25
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• pp.13-19
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• 1979

Circadian susceptibility of sleeping induced by pentobarbital was observrd in male DDO mouse treated with phenobarbital and ginseng saponin. The pentobarbital elimination rate was also measured in the same animal. The mouse had been maintained for one week under 12 hours of artificial illumination extending from 06:00 to 18:00 hours alternating with 12 hours of darkness. During the period the animals were administered intraperitoneally with 100mg/kg of phenobarbital for three days or 10mg/kg and 100mg/kg of ginseng saponin for seven days. At 24 hours after last injection pentobarbital sleeping time and elimination rate were measured following intraperitoneal administration of 50mg/kg of pentobarbital sodium. In a control group treated with saline, the duration of pentobarbital-induced sleep varied with circadian rhythmicity, which had a trough at 02:00 hours of light phase and a crest at 14:00 hours of dark phase. And the elimination rate measured at 02:00 hours was faster than that at 14:00 hours. Pretreatment with phenobarbital markedly shortened the pentobarbital steeping time and abolished the circadian rhythmicity. Those were correlated with the increased pentobartital elimination by phenobarbital throughout light and dark phases examined. Ginseng saponin, given for seven days in a dose of 10mg/kg or 100mg/kg, did not affect the circadian rhythmicity of sleeping and the elimination rate. Sleeping time during light phase, however, was somewhat shortened in ginseng treated animals, which was not matched with the finding of unaltered elimination rate. It seemed that the central nervous system stimulating effect of ginseng saponin might be involved in the findings observed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.180-186
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• 2017

In this paper we propose a traffic aware Demand Wakeup MAC(TADW-MAC) protocol, in which low data delay and high throughput can be achieved, for wireless sensor networks. With the TADW-MAC protocol, the problem of the DW-MAC protocol, which schedules only one packet to deliver during the Sleep period in a multi-hop transmission is resolved. DW-MAC is not adequate for the applications such as object tracking and fire detection, in which busty data should be transmitted in a limited time when an event occurs [6-8]. When an event occurs, duty cycle can be adjusted in the TADW-MAC protocol to get less energy consumption and low latency. The duty cycle mechanism has been widely used to save energy consumption of sensor node due to idle listening in wireless sensor networks. But additional delay in packet transmission may be increased in the mechanism. Our simulation results show that TADW-MAC outperforms RMAC and DW-MAC in terms of energy efficiency while achieving low latency.

• Journal of Korean Public Health Nursing
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• v.10 no.1
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• pp.80-94
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• 1996

This study was to investigated the complaints of physical and mental health problem of professors and officials in H University of Seoul and collected during the period from April 25 to May 31. 1995. The complaints of physical and mental health problem were measured by Cornell Medical Index. The results of this study are as follows: 1. Among the items of physical health problem. respondents showed the highest rate of complaints related to fatigability. and among the items of mental health problem. respondents showed the highest rate of complaints related to inadequacy. 2. Females showed significantly higher rates of complaints related to the musculoskeletal system(p<0.001), fatigability(p<.001). habits(p<.01), inadequacy(p<.05). and tension(p<.001) compared with those of males. Twenties showed significantly higher rates of complaints related to the digestive system(p<.01) compared with those of other age groups. Singles showed significantly higher rates of complaints related to the digestive system(p<.05). inadequacy(p<.01) and depression(p<.001) compared with those of marries. Officals showed significantly higher rates of complaints related to the cardiovascular system(p<.01). digestive system(p<.05), musculoskeletal system(p<.05), and tension(p<. 05) compared with those of professors. Resondents who have irregular eating habits showed significantly higher rates of complaints related to the digestive system(p<.01), musculoskeletal system(p<.05). habits(p<.05). and depression(p<.001) compared with those of respondents who have regular eating habits. Respondents who usually sleep below 6 hours a day showed significantly higher rates of complaints related to the cardiovascular system(p<.01). digestive system(p<.05). musculoskeletal system(p<.01). fatigability(p<.05). habits(p<.01). and tension(p<.05) compared with those of respondents who sleep above 6 hours.

• Journal of Society of Preventive Korean Medicine
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• v.10 no.1
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• pp.95-107
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• 2006

This study was explore the level of Yangseng by certain elderly people in Dalian, china. The subject of this study is(randomly) selected Dalian residents over 65 years-old. We used a formultaed questionnaire for this research during the period from October 2004 to November. 266 subjects in total answered to the questionnaire. The analyses are as follows: 1. Man does more Exercise Yangseng than woman. Elderly with spouse has better Total of Yangseng, Exercise Yangseng, Seasonal Yangseng, Sex life Yangseng than single elderly. Compare to elderly living with family other than their spouse, single elderly has better Total of Yangseng, Diet Yangseng, Activities and rest Yangseng, Exercise Yangseng, Sex life yangseng. 2. Educated elderly has better life than illiterate in every aspects except Diet Yangseng and Seasonal Yangseng. Elderly who does not belive in any religion has better Activities and rest Yangseng and Seasonal Yangseng. Religious elderly has better sleep yangseng than irreligioius elderly. Elderly with occupation has better Total of Yangseng, Activities and rest Yangseng, Exercise Yangseng and Sex life Yangseng. 3. Elderly who support himself of the living expense has better Sleep Yangseng, and elderly who support himself with his sons and daughters has better Morality Yangseng, Exercise Yangseng, Seasonal Yangseng and Sex life Yangseng. Elderly who has time to spare has better life than elderly who has bo leisure in Total of Yangseng and other 8 sub-factors.

• Journal of Preventive Medicine and Public Health
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• v.45 no.1
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• pp.14-20
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• 2012

Objectives: The aim of this study was to evaluate and quantify the risk of both individual and combined health behaviors on premature mortality in middle aged men in Korea. Methods: In total, 14 533 male subjects 40 to 59 years of age were recruited. At enrollment, subjects completed a baseline questionnaire, which included information about socio-demographic factors, past medical history, and life style. During the follow-up period from 1993 to 2008, we identified 990 all-cause premature deaths using national death certificates. A Cox proportional hazard regression model was used to estimate the hazard ratio (HR) of each health risk behavior, which included smoking, drinking, physical inactivity, and lack of sleep hours. Using the Cox model, each health behavior was assigned a risk score proportional to its regression coefficient value. Health risk scores were calculated for each patient and the HR of all-cause premature mortality was calculated according to risk score. Results: Current smoking and drinking, high body mass index, less sleep hours, and less education were significantly associated with all-cause premature mortality, while regular exercise was associated with a reduced risk. When combined by health risk score, there was a strong trend for increased mortality risk with increased score (p-trend < 0.01). When compared with the 1-9 score group, HRs of the 10-19 and 20-28 score groups were 2.58 (95% confidence intervals [CIs], 2.19 to 3.03) and 7.09 (95% CIs, 5.21 to 9.66), respectively. Conclusions: Modifiable risk factors, such as smoking, drinking, and regular exercise, have considerable impact on premature mortality and should be assessed in combination.

• The Korean Journal of Health Service Management
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• v.5 no.2
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• pp.119-129
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• 2011

A researcher examined 158 medical technologists and 140 radiologists who are working at 9 general hospitals in Gyeongsangbuk-do area using structured questionnaire to find out degree of fatigue of health professionals, the primary factors that have effect on them, and actions to control their fatigue on December 1 through December 20, 2008. The average complaining rate of fatigue subjective symptom by syndromes was overall 17.24 points, and medical technologists scored 16.48 points while radiologists scored 18.09 points. There were significant difference in the average fatigue complaining score of both medical technologists and radiologists such as when the younger their age is, when they are single, when the lower their monthly salary is, when the shorter their total working period is, and when the current status is staff at work. As a result of multiple regression analysis which sets fatigue score as dependent variable, there were significant difference on both syndromes such as satisfaction on work, work stress, and sleeping condition. It was the highest on relaxation, which was 76.6%, among the 15 questions on actions to control fatigue, and the next was enough sleep and controlling stress. And the lowest was help from medical professionals, which was 7.3%. It was the highest on enough sleep, which was 1.98 points, and next was relaxation and controlling stress, and the lowest points were help from medical professionals and taking medicine in the effective score of fatigue control action. In consequence of research, it is necessary to develop program and health education to control health professionals' various fatigue such as stress management and sleeping, and it is considered to find out the plan about effective work system.

• Women's Health Nursing
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• v.28 no.3
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• pp.222-234
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• 2022

Purpose: This study investigated the changes in the health-related behaviors of adult women in Korea during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Data from the eighth Korea National Health and Nutrition Examination Survey (2019-2020) were analyzed. The participants were 4,848 women aged 19 to 64 years in 2019 and 2020. Data analysis using the complex sampling design was performed using SPSS 20.1. Results: Positive changes during the pandemic compared to before the pandemic in Korean adult women were found for improved subjective oral health perceptions (odds ratio [OR], 1.77; p<.001), increased moderate-intensity exercise in work and leisure activities (OR, 1.75; p<.001 and OR; 1.29, p=.004), and a decrease in secondhand smoke exposure at the workplace and in public places (OR, 0.64; p=.004 and OR, 0.60; p<.001). However, the following negative health behavior changes were found: decreased frequency of walking 5 days a week (OR, 0.81; p=.011) and an increase in unhealthy daytime sleep durations (OR, 1.40; p=006). Conclusion: Compared to before the COVID-19 pandemic, Korean adult women perceived their subjective dental health more positively during the COVID-19 pandemic, decreased their exposure to secondhand smoke at work and in public places, decreased walking, and increased sleep duration during the week. Since this study only compared data between 1 year before and after the start of the pandemic, it is necessary to investigate a longer period of time in the future. A future study should attempt to identify the factors related to changes in health behaviors caused by the pandemic.