• Title/Summary/Keyword: 주기기

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절연유열화센서를 이용한 변압기 ON-LINE 진단(上)

  • 강장원
    • Electric Engineers Magazine
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    • v.183 no.11
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    • pp.49-53
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    • 1997
  • 산업의 발전과 자동화, 자동화에 따라 전력설비도 점차 대형화 초고입화되고 있는 추세에 있어 전력설비 사고시 그 피해도 막대해지고 있으나 주기적으로 점검을 하여 사고를 사전에 예방하기에는 매우 어려운 것이 현실이다.

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분실단말기 집중관리센터 운영 현황

  • Go, Jung-Heung
    • 정보화사회
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    • s.129
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    • pp.39-41
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    • 1999
  • '99. 4월부터 "PCS폰 주인찾아주기"운동 일원화로 한국정보통신진흥협회는 신세기통신과 PCS 3사가 참여한 가운데 분실단말기 집중관리센터를 개소, 운영해 오고 있다.

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Fringe Sensitivity of Projection Moire Topography Due to Position of Light Source and Object Distance According to Grating Periods (영사식 무아레 토포그래피에서 격자 주기에 따른 물체거리와 광원의 위치에 대한 무늬 민감도 변화)

  • Oh, Hyun Seock;Ju, Yun Jae;Jo, Jae Heung
    • Korean Journal of Optics and Photonics
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    • v.27 no.2
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    • pp.67-72
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    • 2016
  • In projection moire topography, the investigation of fringe sensitivity, which means the change rate of fringe order according to object height, is important and necessary to reduce the measurement error of the shape of an object. Using the fringe sensitivity, the determination of the absolute orders of moire fringes can be performed very easily and rapidly. The important parameters in the determination of absolute orders of fringes are the positions of light source and object, and the grating period in projection moire topography. Among these parameters, the fringe sensitivity due to the transverse motion of the light source and the longitudinal motion of the object according to grating periods are analyzed and compared. As a result, whereas the fringe sensitivity in the transverse-motion method increases linearly and gradually as the distance between light source and imaging sensor increases, the fringe sensitivity due to the longitudinal-motion method decreases dramatically as the distance between imaging lens and object increases. In these methods, the fringe sensitivity and its change increase as the grating period increases.

Analysis on the Results of Measured Concentration of the Combustion Gases Considering Respiration Characteristics in Gasoline Pool Fire (가솔린 풀 화재에서 인체 호흡량 변화를 고려한 연소가스 농도 측정 결과 분석)

  • Choi, Seung Il;Kang, Jung Ki;You, Woo Jun
    • Fire Science and Engineering
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    • v.33 no.4
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    • pp.83-88
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    • 2019
  • This study examined the concentration of combustion gases while considering low ventilation and respiration frequency. A one-quarter-size ISO 9705 room corner test was performed. The concentrations of carbon monoxide and oxygen were measured in each case with the continuous inhalation of combustion gas with low ventilation (2, 6, and 10 LPM) and different respiration frequencies (2 s, 5 s, and infinity). The combustion of a gasoline pool fire in the compartment had a theoretical heat release rate of 5.34 kW. The results show that the deviation of the gas concentrations becomes higher as the low ventilation increases compared to the respiration frequency. In addition, as the respiration frequency increases, the variation in the minimum oxygen concentration is larger than the average value, while in the case of carbon monoxide, the variation in the average value is larger than the maximum value. These results show that the inhalation characteristics of refugees should be considered to investigate fires.

The Characteristics of a Life Cycle of a Theme Park - A Case Study of Everland in Yongin, Korea - (테마파크 에버랜드의 수명주기 특성)

  • Park, Yang-Choon;Choi, Jeong-Su
    • Journal of the Korean association of regional geographers
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    • v.8 no.1
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    • pp.20-39
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    • 2002
  • The purpose of this study is to analyze the characteristics of a life cycle of a theme park through looking at Everland in Yongin, Korea. The life cycle of Everland is divided into four stages. In "initial development" stage(1976 - the mid-80's), Everland become inclined the characteristics of an amusement park by constructing the amusement facilities in the Flower Center(botanical garden). In "growth" stage(the mid-80's - the early 90's), Everland had full grown to the amusement park and inclined to a theme park. In "maturity" stage(the early 90's - the mid-90's), many visitors were not motivated to re-visit Everland because the facilities and events did not change often. Therefore, Everland makes plans for multiple theme park. In "rejuvenation" stage(after the mid-90's), Everland has practiced the plans for multiple theme park and has become the family and accommodating-oriented theme resort park. Since 1976 when Everland was opened, it has evolved from an amusement park to a theme park by creating various and continuous innovations in facilities and events.

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Histological Study on the Reproductive Cycle of Coilia nasus (웅어, Coilia nasus의 생식주기에 관한 조직학적 연구)

  • 이봉우;정의영;이정열
    • Journal of Aquaculture
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    • v.16 no.3
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    • pp.179-186
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    • 2003
  • Reproductive cycle, gonadal development and the spawning period of the Korean anchovy Coilia nasus were investigated by histologhical observations. Samples were collected at the coastal area of Geumgang dyke which is connected to Gunsan and Janghang, Korea, from February 2002 to January 2003. C. nasus is dioecious; the ovary consists of a pair of saccular structure with many ovarian lobules, and the testis consists of a pair of lobular structure with many testicular lobules and connected to the posterior seminal vesicle. Monthly changes in the gonadosomatic index (GSI) began to increase in April when seawater temperature increased and reached the maximum in June when the ovary was getting mature, the summer season of longer day length with higher water temperature. The reproductive cycle can be classified into five successive stage in females: early growing stage (February to March), late growing stage (March to April), mature stage (May to June), ripe and spent stage (June to July), and recovery and resting stage (July to January): in males, the cycle can be divided into four successive stages; growing stage (February to April), mature stage (May to July), ripe and spent (June to July), and recovery and resting stages (July to January). According to the frequency distributions of egg diameters in the spawning season. C. nasus is presumed to be summer spawning species and polycyclic species to spawn 2 times or more during the spawning season.

Dynamic Characterization of Passive Flow-Rate Regulator Using Pressure-Dependent Autonomous Deflection of Parallel Membrane Valves (압력에 따른 평행박막 밸브의 자율 변형을 이용한 수동형 유량 제어기의 동적특성 평가)

  • Doh, Il;Cho, Young-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.8
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    • pp.825-829
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    • 2011
  • We performed a dynamic characterization of passive flow-rate regulators, which compensate for inlet pressure variation and maintain a constant flow rate for precise liquid control in microfluidic systems. To measure the flow rate for a short time, much less than the period of the dynamic inlet pressure, we use the particle image velocimetry (PIV) method. DI water containing fluorescent beads with a $0.7-{\mu}m$ diameter was supplied to the flow-rate regulators, and two successive images of the particles were taken by a pulse laser and a fluorescent microscope to measure the flow velocity. For a dynamic inlet pressure of frequency 60 Hz, the flow velocity was constant with an average of 0.194 ${\pm}$ 0.014 m/s as the inlet pressure varied between 20 kPa to 50 kPa. The flow-rate regulators provided a constant flow rate of $5.82{\pm}0.29\;{\mu}l/s$ in the frequency range of the inlet pressure from 1 Hz to 60 Hz.

Changes in the girth of anthropometric variables during menstrual cycle in women university students (여자대학생의 생리주기에 따른 인체계측변인 둘레의 변화)

  • Kim, Young-Sun;Kang, Seol-Hee;Kim, Yun-Jung;Park, Won-Yeop;Jang, Jee-Hun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.5
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    • pp.421-429
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    • 2021
  • The purpose of this study was to identify the change in the girth of anthropometric variables during menstrual cycle, and to provide basal data for health promotion program development during pre-menstrual phase and menstrual phase. Participants were 10 healthy women university students without menstrual irregularity, subjective premenstrual syndrome, premenstrual dysphoric disorder, dymenorrhea, obstetrician and gynecologic disease. Chest girth(axillary and papillary), waist girth(half point between iliac crest and 12th rib, and navel), and hip girth were repeatedly measured in menstrual phase, follicular phase, luteal phase during single menstrual cycle. As a result, axillary chest girth in menstrual phase was significantly increased than that in luteal phase. Papillary chest girth and waist girth at half point between iliac crest and 12th rib in menstrual phase were significantly increased than those in follicular phase. No significance was shown in chest and waist girth between follicular and luteal phase. No significance was shown in hip girth during menstrual cycle. In conclusion, signicant difference was shown in chest and waist girth during menstrual cycle. And it is suggested that succeeding research should be carried out with reference to body weight, body fat, blood and local hormone concentration during menstrual cycle.