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정근화,손진욱 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.6
In order to investigate the sleep habits of farmers in a rural area, we studied 270 subjects(farmers) in a rural area from August 14, 1995 to August 19, 1995. Sleep habits were analyzed according to age groups(3 groups of 18-30, 31-50, over 51 years) and sex. The results were as follows : 1) The mean sleep length was 6.7±1.5 hours, and was longer in female than in male. In the above 51-year-old age group, sleep length was significantly shorter than those in the other two age groups. 2) The mean sleep latency was 21.6±21.5 minutes, and was longer in female than in male. There were no significant differences in sleep latency among age groups. 3) The sleep onset time was later in the 18-30-year-old age group than in the other two age groups. The awakening time was earlier in the over 51-year-old age group than in the other two age groups. 4) One hundred and four subjects(38.5%) complained difficulty falling asleep, 196 subjects(72.6%) complained fragmented sleep, and 86 subjects(31.9%) complained early morning awakening during the past two weeks. Difficulty falling asleep and fragmented sleep were more common in females than in male. 5) One hundred and seventeen subjects(43.3%) had napped during the past two weeks and there were no significant differences among age groups. 6) One hundred and sixty five subjects(61.1%) experienced daytime drowsiness during the past two weeks and there were no significant differences among age groups. 7) Ninety-one subjects(33.7%) reported nightmares, 32 subjects(11.9%) reported sleeptalking 3 subjects(1.1%) reported sleepwalking, and 15 subjects(5.6%) reported bruxism during past two weeks.
Shon Jin-geun,Lee Hyun-jae,Moon Hak-ryong,Seung-hwa Park 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.2
The purpose of this paper is to quickly and accurately perform the maximum power point tracking (MPPT) of a photovoltaic panel in accordance with the surrounding environment of variously changing photovoltaic systems. In this photovoltaic system, a power conversion system is confi gured with a diff erential power processing (DPP) structure to perform MPPT, and a method for improving this MPPT performance is proposed. MPPT is performed using the charging characteristics of the attached capacitor for voltage smoothing of the MPPT PV panel based on the proposed voltage reference model. The voltage reference model-based MPPT was applied to the proposed DPP structured photovoltaic system. Therefore, by enabling the expansion of the application of a high-effi ciency photovoltaic system that has better power generation performance and can be adapted to various climate and temperature changes, a safer power generation system having less power loss was implemented to verify performance. It is also expected that by reducing the number of sensors in the system, annual maintenance costs will be reduced.
개선된 계측 및 스위칭 기법을 이용한 정전류조정 인버터 시스템
孫珍劤(Jin-Geun Shon),徐一東(Il-Dong Seo),田喜鐘(Hee-Jong Jeon) 대한전기학회 2007 전기학회논문지 P Vol.56 No.4
As development of industry is accelerated, most electricity load system requires power supply that could be high precision and effective control. Among supply and control unit of suitable power supply in these load characteristic, inverter systems of constant current regulate is used widely control of lighting & beaconing of aerodromes and electric heating system. Therefore, in this paper proposed a inverter systems of constant current regulate that using improved measurement and switching techniques. Proposed measure techniques that used moving average method of instantaneous r.m.s. for measuring current sensing improved response and precision. Also, in this paper proposed improved high effectiveness switching techniques that get high efficiency of inverter by the double-carrier modulation. Results of an experiment proved effect of proposed system.
DC/DC 컨버터를 이용한 DC Bus 커패시터의 간단한 ESR 측정 기법
손진근(Jin-Geun Shon),김진식(Jin-Sik Kim) 대한전기학회 2010 전기학회논문지 P Vol.59 No.4
Electrolytic capacitors have been widely used in power electronics system because of the features of large capacitance, small size, high-voltage, and low-cost. Electrolytic capacitors, which is most of the time affected by aging effect, plays a very important role for the power electronics system quality and reliability. Therefore it is important to estimate the parameter of an electrolytic capacitor to predict the failure. The estimation of the equivalent series resistance(ESR) is important parameter in life condition monitoring of electrolytic capacitor. This paper proposes a simple technique to measure the ESR of an electrolytic capacitor. This method uses a switching DC/DC boost converter to measure the DC Bus capacitor ESR of power converter. Main advantage of the proposed method is very simple in technique, consumes very little time and requires only simple instruments. Simulation results are shown to verify the performance of the proposed method.
전력변환기에 대한 직류링크 커패시터의 고장진단을 위한 간단한 용량 추정 기법
손진근(Jin-Geun Shon),김동준(Dong-Joon Kim) 대한전기학회 2010 전기학회논문지 P Vol.59 No.4
Due to the large capacity and low cost, DC link electrolytic capacitors with of energy storage and voltage regulation are used for almost all types of power converter as the DC/AC inverter or DC/DC converter. Electrolytic capacitor, which is the most of the time affected by the aging effect, plays very important role for the power converter system quality and reliability. Therefore, this paper proposes a simple method to estimate the capacitance variation of an electrolytic capacitor in order to analyze the internal characteristic decrease and worn-out state of an electrolytic capacitor. Simulation results by using capacitor storage energy computation show the validity of the proposed capacitance estimation method.
Super-Capacitor의 고장진단을 위한 파라미터의 특성 해석
손진근(Jin-Geun Shon),김용혁(Young-Hyuk Kim),김동준(Dong-Joon Kim),이상철(Sang-Cheol Lee) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.11
본 논문에서는 Super-Capacitor라 불리우는 EDLC(전기이중층콘덴서)의 고장진단을 위한 파라미터의 특성 해석에 관한 연구를 수행하였다. 에너지의 저장 및 전압연계를 위한 전력변환장치에는 납축전지 또는 전해커패시터를 사용하여 왔으나 환경문제 및 에너지밀도의 측면에서 불리하여 최근에는 Super -Capacitor의 사용이 주목을 받고 있다. 본 논문에서는 이러한 EDLC의 내부 특성을 해석하기 위하여 EDLC의 등가직렬저항 및 정전용량을 측정하여 진단데이터에 활용이 가능토록 하였으며, 또한 EDLC를 적용한 순간전압 보상장치의 응용 실험을 수행하여 그 결과를 제시하였다.
전력변환장치에서의 DC 출력 필터 커패시터의 온라인 고장 검출기법
손진근(Jin-Geun Shon) 대한전기학회 2009 전기학회논문지 P Vol.58 No.4
Electrolytic capacitors are used in variety of equipments as smoothening element of the power converters because it has high capacitance for its size and low price. Electrolytic capacitors, which is most of the time affected by aging effect, plays a very important role for the power electronics system quality and reliability. Therefore it is important to estimate the parameter of an electrolytic capacitor to predict the failure. This objective of this paper is to propose a new method to detect the rise of equivalent series resistor(ESR) in order to realize the online failure prediction of electrolytic capacitor for DC output filter of power converter. The ESR of electrolytic capacitor estimated from RMS result of filtered waveform(BPF) of the ripple capacitor voltage/current. Therefore, the preposed online failure prediction method has the merits of easy ESR computation and circuit simplicity. Simulation and experimental results are shown to verify the performance of the proposed on-line method.