• Sleep Medicine and Psychophysiology
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• v.14 no.1
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• pp.26-32
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• 2007

Objectives: Angiotensin-converting enzyme (ACE) gene polymorphism has been reported to be associated with depression and therapeutic outcome in depression. The purpose of this study was to determine whether ACE gene polymorphism is associated with seasonal variation in mood and behavior in a young Korean college student sample. Methods: 297 young Korean medical students were recruited in this study. All subjects were free of major medical and psychiatric problems. They were genotyped for the ACE gene polymorphism and evaluated the seasonal variation in mood and behavior by the Seasonality Pattern Assessment Questionnaire (SPAQ). Results: Global Seasonality Score (GSS) of SPAQ between three genotypes were not different. However, comparison of the group that showed seasonality of mood and behavior during winter with the group that did not showed seasonality indicated significant difference in genotype distribution ($x^2=6.79$, p=0.034). The D allele non-carrier (ll genotype) frequency was significantly higher in winter seasonality group than non-seasonality group ($x^2=6.59$, p=0.010；odds ratio [OR]=2.27, 95% confidence interval [CI] 1.20-4.28). Conclusion: These results suggest that the ACE gene polymorphism is related to winter-type seasonality in a Korean population.

• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.349-355
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• 2015

Background: The tuberculin skin test (TST) is the standard tool to diagnose latent tuberculosis infection (LTBI) in mass screening. The aim of this study is to find an optimal cut-off point of the TST+ rate within tuberculosis (TB) contacts to predict the active TB development among adolescents in school TB outbreaks. Methods: The Korean National Health Insurance Review and Assessment database was used to identify active TB development in relation to the initial TST (cut-off, 10 mm). The 7,475 contacts in 89 schools were divided into two groups: Incident TB group (43 schools) and no incident TB group (46 schools). LTBI treatment was initiated in 607 of the 1,761 TST+ contacts. The association with active TB progression was examined at different cut-off points of the TST+ rate. Results: The mean duration of follow-up was $3.9{\pm}0.9years$. Thirty-three contacts developed active TB during the 4,504 person-years among the TST+ contacts without LTBI treatment (n=1,154). The average TST+ rate for the incident TB group (n=43) and no incident TB group (n=46) were 31.0% and 15.5%, respectively. The TST+ rate per group was related with TB progression (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.001-1.050; p=0.037). Based on the TST+ rate per group, active TB was best predicted at TST+ ${\geq}$ 16% (OR, 3.11; 95% CI, 1.29-7.51; area under curve, 0.64). Conclusion: Sixteen percent of the TST+ rate per group within the same grade students can be suggested as an optimal cut-off to predict active TB development in middle and high schools TB outbreaks.

• Anxiety and mood
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• v.15 no.2
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• pp.115-121
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• 2019

Objective : The purpose of this study was to investigate prevalence of psychiatric symptoms and determine predictors of emotional distress of military hospital surgical patients. Methods : This study examined 104 orthopedic patients admitted to the Armed Forces Military Hospital September-November 2018. For the study, every subject completed self-assessment inventories regarding depressive and anxiety symptoms (Hospital Anxiety and Depression Scale), sleep problems (Pittsburgh Sleep Quality Index), problematic alcohol and tobacco use (Cut off, Annoyed, Guilty, Eye-opener screening), and psychiatric history. We performed the Student's t-test and the chi-square test for the collected data to investigate the prevalence of psychiatric symptoms, including emotional distress. Logistic regression analysis was used to examine the risk factors related to emotional distress of hospitalized military personnel. Results : There were no significant differences in socio-demographic and psychiatric symptoms between soldiers and officers. The prevalence of depressive and/or anxiety symptoms (emotional distress) was 21.2% (n=21). In the logistic regression analysis, psychiatric history [Adjusted Odds Ratio (AOR)=18.99 ; 95% Confidence Interval (CI)=1.42-253.57 ; p=0.026] and low military life satisfaction (AOR=15.67; 95% CI=1.46-168.11 ; p=0.023) correlated with emotional distress. Conclusion : Soldiers admitted to the military hospital showed similar prevalence of emotional distress as those at general hospitals. Considering military circumstances, it is necessary to detect and intervene regarding soldiers with a psychiatric history and low military life satisfaction to promote mental health at military hospitals.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.7
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• pp.335-343
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• 2006

We have designed the system that measure one channel ECG by two electrode and extract real-time EDR with more related resipiration and comportable to subject by using conductive textile. On the assumption that relation between RL electrode and potential measurement electrode is coupled with RC connected model, we designed RL drive output to feedback two electrode for reduction of common mode signal. The conductive textile which was used for two ECG electrode was offered more comfort during night sleep in bed than any other method using attachments. In the method of single-lead EDR, R wave point or QRS interval area could be used for EDR estimation in traditional method, it is, so to speak, the amplitude modulation(AM) method for EDR. Alternatively, R-R interval could be used for frequency modulation(FM) method based on Respiratory Sinus Arrhythmia(RSA). For evaluation of performance on AM EDR and FM EDR from 14 subject, ECG lead III was measured. Each EDR was compared with both temperature around nose(direct measurement of respiration) and respiration signal from thoracic belt(indirect measurement of respiration) on mean squared error(MSE), cross correlation(Xcorr), and Coherence. The upsampling interpolation technique of multirate signal processing is applied to interpolating data instead of cubic spline interpolation. As a result, we showed the real-time EDR extraction processing to be implemented at micro-controller.

• Safety and Health at Work
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• v.12 no.3
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• pp.390-395
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• 2021

Background: Health-care providers typically undergo shift work and are subjected to increased stress. Night shift work may induce disturbed sleep cycles and circadian rhythm. The objective of this study was to explore if night shift workers (NSWs) show an increased risk of abnormal thyroid-stimulating hormone (TSH). Methods: We conducted a retrospective cohort study of 574 employees without thyroid disease and abnormal TSH at baseline who underwent annual check-ups between 2007 and 2016 in a medical center. NSWs were defined as those with working time schedules other than daytime hours. We calculated the incidence rate and estimated the adjusted hazard ratio (HR) for incident abnormal TSH and subclinical hypothyroidism compared with non-NSWs using a Cox regression model. Results: A total of 56 incident abnormal TSH cases and 39 subclinical hypothyroidism cases in NSWs were identified during 3000 person-years of follow-up. In models adjusted for age, sex, obesity, and working departments, we found no increased relative risk for incident abnormal TSH (HR: 0.72, 95% confidence interval: 0.33-1.60) or subclinical hypothyroidism (HR: 0.52, 95% confidence interval: 0.19-1.45) when comparing NSWs to non-NSWs; nor were incidence rates significantly different among exclusively medical employees after excluding administrative staff. Conclusion: In this hospital-based nine-year follow-up retrospective cohort study, NSWs were not associated with increased relative risk of incident abnormal TSH and subclinical hypothyroidism, in contrast to previous cross-sectional studies.

• Safety and Health at Work
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• v.12 no.3
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• pp.384-389
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• 2021

Background: Social distancing by working-from-home is an effective measure to decrease the spread of COVID-19. However, this new work pattern could also affect the well-being of workers. Therefore, the aim of the study was to study the magnitude of occupational health problems and lifestyle changes among workers who have only recently started working from home. Methods: A cross-sectional study was conducted using online self-administered questionnaires during the coronavirus disease 2019 pandemic in the Bangkok metropolitan area, Thailand. The participants were from any organization that allowed working from home. The demographic data including the analysis of the characteristics of working from home, the occurrence of occupational health problems, and the lifestyle changes caused by working from home were analyzed. Results: A total of 869 workers were included as study participants. The highest prevalence of physical health problems among all workers was identified to be weight gain at a rate of 40.97% (95% confidence interval = 37.69-44.24), and the highest prevalence of psychosocial problems was identified to be cabin fever at a rate of 31.28% (95% confidence interval = 26.66-35.90%) among full-time working-from-home workers. The health effects that were significantly related to the intensity of working from home (p for trends <0.05), either positively or negatively, included body weight changes, ergonomic problems, indoor environmental problems, and psychosocial problems. Meanwhile, the lifestyle changes related to work intensity included eating pattern, sleep habits, and exercise. Conclusions: Working from home can affect workers' well-being in various aspects. Hence, occupational health providers must prepare for risk prevention and health promotion in this "new normal" working life pattern and for future pandemics.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.167-172
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• 1998

Methods of evaluating the physiological activity of the living body are EEG, EOG, Heart rate, and Rectal temperature, etc. In the study of Hagiwara and Araki(1993), they found positive correlations among performance test, physiological measurement, and subjective feeling measurement. Human alertness of pilot directly influences on the flight performance that accomplishes a lot of vigilance task and procedure execution in flight. Accordingly, this paper deals with the quantitative and objective performance test based on tracking error and reaction time by means of the new computer test program into which the perception-motion system of human beings is applies. Throughout this experiment using performance thst, the results suggest that performance capability in state of sleep deprivation 2 hours and alcoholic 0.05 .apaprox. 0.06% in blood were more impaired than one in a normal state, and they further showed statistically significant differences between them, which were influenced by impairment factors of body regulation and pilot's grade. We also obtained the prediction value and the 95% confidence interval of tracking error and reaction time at the normal state for the purpose of distinguishing performance capability between the normal state and the abnormal state. And it is ecpected that the evaluation of human alertness using performance test will be applied to the quantitative assessment of an each pilot's realistic consciousness/attention, and will lead a flight commander to the accurate decision of mission approval prior to a flight.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.12
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• pp.1045-1053
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• 2013

In this paper, we propose a new power-saving mechanism (PSM) for Long-Term Evolution (LTE) systems by considering a round-trip delay between a user equipment (UE) and its correspondence node. The proposed PSM changes the order of the operational procedures of the legacy LTE PSM by taking the traffic arrival pattern suffering the round-trip delay into account. After modeling the round-trip delay, we numerically analyze the proposed PSM with respect to energy consumption and buffering delay. Then, we characterize these performances by employing a simple energy-delay tradeoff (EDT) curve according to the operational parameters. The resulting EDT curve clearly shows that the proposed PSM outperforms the legacy LTE PSM in terms of both the energy consumption and buffering delay.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.625-630
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• 2006

Zigbee 센서 네트워크에서는 multihop 전송을 위하여 tree topology와 beacon-enabled 네트워크 구성을 갖는다. 이러한 multihop beaconing 네트워크의 목적은 routing 노드들에게 Sleep할 기회를 주어 파워의 소모를 줄이고자 하는 데 있다. 파워의 소모를 줄이고 beacon 전송시의 충돌을 방지하기 위하여 beacon 전송 스케줄링이 필요한데 본 논문은 multihop을 지원하고 에너지 효율에 효과적인 beacon 전송 스케줄링 알고리즘과 이를 바탕으로 에너지 효율적인 라우팅 기법을 제안한다. 본 제안은 Zigbee coordinator의 beacon interval(BI)이 결정되면 네트워크 내의 beacon을 전송하는 모든 노드들은 Zigbee coordinator의 BI를 알고 모든 노드의 superframe duration(SD)은 동일하다고 가정한다. 이러한 가정하에서 beacon을 전송하는 노드들이 Zigbee coordinator의 BI 구간 중 항상 정해진 시간에 자신의 beacon을 전송한다면 beacon의 충돌을 막을 수 있음을 보여 준다. 또한 노드들이 서로의 beacon 전송 시간을 알 수 있기 때문에 목적지 노드의 beacon을 tracking하지 않고도 목적지 노드가 active 되는 시점에 패킷을 전송하면 에너지 측면에서 좀 더 효율적인 라우팅 기반을 제공한다는 것을 보여 준다.

• The Journal of Pediatrics of Korean Medicine
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• v.21 no.3
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• pp.177-188
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• 2007

Objectives The purpose of this study is to investigate the effects of simultaneous treatment with supplementary therapy and treatment interval for improving symptoms and satisfaction rate by treating child rhinitis or paranasal sinusitis patients. Methods 41 rhinitis or paranasal sinusitis patients who visited the clinic between April 2004 and April 2006 were involved for this study. The patients were classified into Group A(2 sessions per week, simultaneous supplementary therapy), Group B(1 session in 2 weeks, simultaneous supplementary therapy) and Group C(1 session in 2 weeks, no supplementary therapy). After the experiment, the improvement rates of symptoms and satisfaction rate were surveyed by the questionnaires. Supplementary therapies used in Group A and B were aroma spray, Saengbit-patch, cutaneous acupuncture, nebulizer and Chuna manipulation. Results From 41 of the rhinitis or paranasal sinusitis patients, the Group A(simultaneous treatment group, 2 sessions of intensive care per week with supplementary therapy) showed the remaining symptoms score of $12.1{\pm}10.0$ in average. This score was the lowest comparing with the average of $25.7{\pm}12.9$ in Group B(1 session in 2 weeks, simultaneous treatment group with supplementary therapy) and the average of $21.0{\pm}20.1$ in Group C(1 session in 2 weeks, no supplementary therapy). Nose symptoms and sleep scores were significantly lower in Group A(p<0.01). The satisfaction score was the highest in Group B that had the most remaining symptoms and it had no significant relationship with the symptom improvement. Additional analysis showed that among many factors such as treatment interval, treatment method, cost, accessibility of the clinic, family history and satisfaction with the doctor; the satisfaction with their doctor was the most closely related to the satisfaction rate of the patients. Conclusions In this study with 41 of rhinitis or paranasal sinusitis patients, the 2 sessions of intensive care group showed the best results in improving symptoms. Supplementary treatments were also used simultaneously; aroma spray, cutaneous acupuncture, Saengbit-patch, Chuna manipulation and nebulizer. The questionnaires showed that the satisfaction rate of the patients(care taker) was not related to the symptom improvement. Additional analysis of the factors that influence the satisfaction rate showed that it was more closely related to the satisfaction with their doctors.