• 산업공학
• /
• 제25권3호
• /
• pp.283-289
• /
• 2012

M/G/1 queue with server vacations period depending on the previous vacation and customer's arrival is considered. Most existing studies on M/G/1 queue with server vacations assume that server vacations are independent of customers' arrival. However, some vacations are terminated by some class of customers' arrival in certain queueing systems. In this paper, therefore, we investigate M/G/1 queue with server vacations where each vacation period has different distribution and vacation length is influenced by customers' arrival. Laplace-Stieltjes transform of the waiting time distribution and the distribution of number of customers waiting for each class of customers are respectively derived. As performance measures, mean waiting time and average number of customers waiting for each class of customers are also derived.

• 한국멀티미디어학회논문지
• /
• 제11권10호
• /
• pp.1392-1402
• /
• 2008

홈 게이트웨이는 유비쿼터스 홈 서비스를 지속적으로 제공하기 위해 24시간 가동되므로 연간 소모하는 전력의 규모가 크다. 네트워크의 유휴 시간에 최소 전력을 사용하는 전력 절감 모드를 적용하면 이러한 전력 소모를 줄일 수 있다. 본 논문의 전력 절감 모드 결정 알고리즘은 유휴 시간이 시작되면 유휴 시간의 누적된 정보를 토대로 현재의 유휴 시간의 길이를 예측하고, 그 결과에 따라 전력 절감 모드로 전환한다. 전력 절감 모드에서 간단한 제어용 프로토콜 데이터는 활성 모드로의 전환 없이 프록시로 처리한다. 그리고 사용자 트래픽이 존재할 경우에만 활성 모드로 전환한다. 이러한 알고리즘을 검증하기 위해서는 흠 네트워크에서 트래픽 데이터를 수집하여, 시뮬레이션을 수행하였다. 그 결과 기존 방식에 비해 최소 14%에서 최대 49%의 전력 절감 효과를 보였다.

• 대한인간공학회지
• /
• 제30권1호
• /
• pp.221-227
• /
• 2011

Objective: The aim of this study is to investigate the quantitative effects of various emotions and retention periods on the color vividness of visual memory. Background: Although numerous studies have focused on the effects of emotions on memory such as visual detail and vividness of emotional events compared to neutral events, the relationship between emotion and visual memory is ambiguous yet. Furthermore, there were few studies on the effect of emotion on vividness of visual memory. Method: A total of 68 subjects were participated in serial experiments proceed on online and the experiments had two phases: recognition phase and reproduction phase. The 15 photographs were used as visual stimuli and all experiments were conducted over the internet(experiment website) and the results were collected on the web database. Results: The retention period, sleep-arousal emotion and subjective saturation of visual stimuli had a significant effect on the color vividness of visual memory. Conclusion: The results suggested that the color of visual stimulus might be more vividly remembered when it is arousing, the subjective saturation is higher and the retention period is longer. Application: The findings of this study may help clarify the relationship between human emotions and visual memory.

• 동의신경정신과학회지
• /
• 제29권4호
• /
• pp.305-314
• /
• 2018

Objectives: The objective of this study was to report the clinical effectiveness of the complex Korean medicine therapy and M&L (Mindfulness & Loving presence) psychotherapy on the patient with panic disorder. Methods: The subject for this study was the patient diagnosed with panic disorder who complained about intermittent panic attack and accompanying insomnia. During the treatment period, the patient received complex Korean therapy and M&L psychotherapy. The clinical effects were evaluated through Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HDRS), State-Trait Anxiety Inventory (STAI), Panic Disorder Severity Scale (PDSS), and Pittsburgh Sleep Quality Index (PSQI). Results: After the complex Korean medicine therapy and M&L psychotherapy, the overall symptoms of depression, anxiety, panic disorder and insomnia of the patient were lessened in a relatively short period. No specificities or adverse effects were reported during the treatment period. Conclusions: This study established that the complex Korean medicine therapy and M&L psychotherapy was effective in treating patients with panic disorder.

• 대한불안의학회지
• /
• 제9권2호
• /
• pp.128-134
• /
• 2013

Objective : As treatments for breast cancer require long period of time, the patients need continuous monitoring and management of their health related quality of life. The purpose of this preliminary study is to explore the utility of monitoring quality of life using a mobile phone based application, which was developed to enable the patients to report daily quality of life more efficiently. Methods : Department of psychiatry, breast cancer center and U-health team of Asan Medical Center collaborated in developing a mobile application titled 'DugunDugun'. Through the application, patients with breast cancer receiving neo-adjuvant chemotherapy could report on various questions about their daily quality of life. We extracted and explored the daily basis of the data of sleep duration, number of awake, sleep satisfaction, mood and anxiety from nine patients who reported on the questionnaire for more than a month. Results : The longitudinal data collected using our mobile application well represented the characteristics of individual sleep patterns and daily emotional changes. Most of the patients showed high daily variations in the scores of their quality of life while their averaged scores were similar among patients. The patient with highest daily variations in the subjective sleep quality and daily emotional change had highest score corresponding to moderate depression in Beck Depression Inventory (BDI). Conclusion : The results suggest that mobile application could be a useful tool for monitoring and collecting the daily quality of life in the patients with breast cancer. We expect that mobile application could facilitate early detection and proper intervention for the cancer patients at psychological crisis.

• 한국전자통신학회논문지
• /
• 제10권11호
• /
• pp.1265-1270
• /
• 2015

무선 센서 네트워크에서 배터리로 동작하는 센서 노드 또는 수집 노드를 위한 에너지 효율을 개선한 MAC 프로토콜은 중요한 성능 요소이다. 본 논문에서는 무선 센서 네트워크를 위한 MAC 프로토콜에서 활성구간과 수면구간을 반복하여 수행하는 Duty Cycle 기법의 고정적인 활성 구간에 따른 제한적인 성능을 개선하기 위해 수신 예측 기반의 주기 적응적 웨이크업 제어 기법을 제안한다. 제안된 기법은 CC2500 RF 트랜시버 및 C8051F330 마이크로컨트롤러 기반의 무선 노드를 이용한 성능평가를 통해 최소의 활성구간을 분석하였고, 주기 변화에 따라 적응적으로 수면구간을 증가시켜 에너지 성능을 향상시킬 수 있음을 확인하였다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제31권2호
• /
• pp.80-87
• /
• 2020

Objectives: The prevalence of psychiatric disorders among young adults is different from that among younger or older age groups because of biological and environmental changes. The purpose of this study was to analyze the diagnostic distribution of psychiatric disorders in 19-30-year-old Koreans based on their age and gender using data from the Korean National Health Insurance Service (NHIS). Methods: From the 2011 medical claims sample data of NHIS of 1,375,842 people, we extracted the data of 221,038 people aged 19-30 years, including 106,232 (48.1%) men and 114,806 (51.9%) women. We evaluated the overall changes in the diagnostic distribution of psychiatric disorders over a 3-year period. Results: The diagnostic frequency in women was 13,627 (59.0%), which was significantly higher than that in men. "Other anxiety disorders" was the most common psychiatric disorder in both genders, followed by depressive episodes, somatoform disorders, "other neurotic disorders," and nonorganic sleep disorders. In men, attention-deficit/hyperactivity disorder or intellectual disabilities were not among the top 10 disorders. In women, no significant changes in major psychiatric disorders were seen over the 3-year period. Conclusion: These results reveal the trends of diagnostic distribution of mental illnesses depending on the development, particularly in young adulthood. It is necessary to identify whether such trends are due to biological or environmental factors, aging processes, or complex influences.

• Advances in Traditional Medicine
• /
• 제6권1호
• /
• pp.21-26
• /
• 2006

The ethanolic extract of Fleurya interrupta Gaud, (Urticaceae) was tested for its possible neuropharmacological effects on experimental animals, For the primary neuropharmacological screening of this plant, the ethanolic extract of its aerial parts was subjected to preliminary evaluation for acute toxicity, antinociceptive activity and central nervous system (CNS) activities. At the doses of 125 and 250 mg/kg, the extract significantly (P < 0.01 and P < 0. 001) and dose-dependently increased the frequency of acetic acid induced writhing in mice. In the pentobarbitone induced sleeping time test, the extract at the above dose levels, significantly and dose-dependently decreased the pentobarbitone induced sleeping time (P < 0.001) and increased the time for onset of sleep (P < 0.001) in mice. In the open field and hole cross tests, test animals showed an increase in their movement in the both tests from the 2nd observation period (30 min) and persisted throughout the entire experimental period (240 min). These results of the extract may attribute a stimulating action on the CNS. On the basis of these findings, it can be assumed that the extract exerts its stimulating effect on the CNS in mice by interfering with the cortical function or increasing the effect of some CNS stimulating neurotransmitters.

• Toxicological Research
• /
• 제12권2호
• /
• pp.231-236
• /
• 1996

The toxicity of the mixture of diazinon, toxaphene(TOX) and/or endrin was studied in ICR male mice(18-22 g) by oral intubation, in corn oil, daily for up to 14 days. On day 15, the exposure was discontinued and animals were monitored for an additional period of 7 days for the possible reversibility of the toxicity. The body weight gain decreased with the mixtures, as well as with the individual pesticides, during the 14-day period. TOX and TOX containing mixtures significantly increased the liver/body weight ratio. The serum glutamic pyruvic transaminase level increased at 23~374% in diazinon, TOX, and endrin or their mixture group. The cholinesterase(ChE) activity in the serum and brain was inhibited in the animals of the group of diazinon(5, 10 mg/kg) and diazinon(5 mg/kg) containing mixtures. TOX(40, 80 mg/kg) caused initial inhibitory effects on the serum ChE Day 1. but there is little effects on the brain ChE levels. endrin(5,10 mg/kg) results in significantly elevated levels of the serum ChE, with substantial decreases in the brain ChE activity. TOX and TOX containing mixtures decreased the pentobarbital(60 mg /kg, ip., in saline) induced sleep. The effects produced by this pesticides singly, as well as by their mixtures, appeared to be reversible in nature. The toxic effects exhibited by the mixtures of diazinon(5 mf/kg), TOX(40 mg/kg), and /or endrin(5 mg/kg) were found to be the resultant of the effect showed by their components individually.

• 생명과학회지
• /
• 제28권8호
• /
• pp.985-991
• /
• 2018

생물시계(Biological clock)는 생명체에서 나타나는 반복되는 자율적인 리듬을 말하며, 단일세포는 물론 다세포 생명체의 기본적인 대사와 이에 따른 표현형과 행동을 직접적으로 조절하고 있다. 이러한 생물시계는 동면 리듬, 수면 리듬, 심장박동 리듬 및 짝짓기 노래 리듬 등 매우 다양하며, 24시간 이상의 주기를 infradian rhythm, 24시간 주기를 circadian rhythm, 24시간 이내의 짧은 주기를 ultradian rhythm으로 구분한다. 효모 Saccharomyces cerevisiae는 최소 5종 이상의 반복되는 자율적인 리듬이 알려져 있으며, 이중 일부는 생체시계로 인식되고 있다. 본 리뷰에서는 Saccharomyces cerevisiae의 glycolytic oscillation (T= 1~30분), cell cycle-dependent oscillation (T= 2~16 시간), ultradian metabolic oscillation (T= 15~50분), yeast colony oscillation (T= 수 시간) 및 circadian oscillation (T= 24시간)에 대한 연구 결과를 제시하고, 특히 ultradian metabolic oscillation의 특징, 집단 동조인자(population synchronizer), 동조인자의 조절 기작 및 효모 생물시계의 대사공학 분야의 이용성을 제시하여 효모를 이용한 동적 대사조절 및 생물시계 연구가 가능함을 제시하였다.