• 제목/요약/키워드: Closed circuit

검색결과 341건 처리시간 0.03초

New and Improved Time-selective Self-triggering Water Sampler: AUTTLE

  • Jin, Jae-Youll;Hwang, Kuen-Choon;Park, Jin-Soon;Eo, Young-Sang;Kim, Seong-Eun;Yum, Ki-Dai;Oh, Jae-Kyung
    • Ocean and Polar Research
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    • 제22권2호
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    • pp.57-67
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    • 2000
  • Time-selective self-triggering water sampler, AUTTLE developed by Jin et al. (1999) has been improved in order to prevent pre-deposition of suspended sediments (SS) before sampling. By using two solenoids, the improved sampler is able to be moored or deployed with inclination. Its position is changed to horizontal position by activating the first solenoid, and then the endcaps of the sampling bottle are closed by the second solenoid that is driven three times to minimize possible failure of sampling. An external control unit for setting sampling time has been also constructed. Additionally, the electric circuit housing of the sampler has been modified to be detached from the sampling bottle when operating manually. Its performance has been confirmed through flume tests and a field experiment. It will serve as a valuable tool in the various fields of oceanography and environmental engineering, especially where seawater sampling synchronized at several sites and/or the information in storm period is important.

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미디어아트를 이용한 패션 액세서리 디자인 (Fashion Accessory Design Using Media Art)

  • 제갈미;이연희
    • 복식
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    • 제58권4호
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    • pp.1-12
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    • 2008
  • The expansion of media art has not only developed the digital technology but also given lots of environmental evolution to improve various fields of design as the main topic of the 21st century. The purpose of this study is aimed at proposing the new design that integrates fashion accessaries with media art technology. This will be done by understanding the social environment in digital ages and studying technology of design based on a variety of literature about changes in our society, neo value, vision, culture and art with fundamental notion of media art. First stage for this study, put an idea into just fashion accessary design because it is not sufficient to incoporate fashion and media art technology. The presented OLED(Organic Light Emitting Diodes) in this study is a kind of display to be in a limelight in the next generation and can be applied to various field of design. media art simultaneously moved into the scope of artistic debates. As a result, we can found that the use of audiovisual introduced numerous new aspects to the conceptual and aesthetic engagement with questions of conception. Today, the presented forms of art and inter-action from the closed -circuit work to interactive media art installations to open process-exist as parallel possibilities.

유압 트랜스포머를 이용한 유압 실린더의 에너지 절감에 관한 연구 (A study of Energy Saving Hydraulic Cylinder System Using Hydraulic Transformer)

  • 안경관;이민수;조용래;윤주현;조우근;윤홍수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1075-1080
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    • 2007
  • In order to reduce energy consumption, secondary controlled system has been applied to many types of equipments. In lifting equipments or press machines using hydraulic cylinder, a hydraulic transformer is used as a control component instead of a valve for motion control and a component for recovering potential energy of load. The transformer is a combination of a variable displacement pump/motor as a secondary controlled element and a fixed displacement pump/motor. In this paper the effect of transformer is studied. Multiple closed loop controllers with displacement feedback of variable pump/motor, speed feedback and position feedback of cylinder are used. The efficiency and energy consumption when cylinder is driven up and down is calculated by simulation. Simulation results show that considerable energy saving is achieved by choosing load ratio, circuit type and supply pressure.

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PDFF 제어기법을 이용한 단상 UPS 인버터 전압, 전류제어에 관한 연구 (A study on single phase UPS inverter control with PDFF method)

  • 오방원;이상용;이용균;전윤석;최규하
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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    • pp.799-802
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    • 2004
  • There are many methods in controlling inverter's voltage and currents. most of all, PI control method is a general method. PI control has some merits. But, PI control has zero effect. So, steady-state response errors always exist by the zero effect. For removing the steady-state error, This paper presents the modeling, design and analysis of the double loop feedback control scheme. and computing the value of parameters and applying In the single-phase full bridge inverter for comparison and analysis between the PI control and PDFF control. The system model is employed to examine the dynamics of power circuit and select appropriate feedback variables for stable operation of the closed-loop UPS inverter system. It analyzes and proves the output characteristic of inverter system with the PDFF control.

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반송정수장 CCTV망의 구조개선을 통한 운영효율화 및 보안성 개선사례에 관한 연구 (A study on operation efficacy and security improvement through structural modification of CCTV network for bansong water purification plant)

  • 박은철;최현주
    • 상하수도학회지
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    • 제32권2호
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    • pp.193-200
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    • 2018
  • Owing to the development in information and communications technologies have improved the technology for high-speed transmission of massive data, which has changed closed-circuit television (CCTV) video transmission technology. In particular, digitization of the CCTV video format and streaming technology has made it possible to minimize transmission loss and integrate video transmission and camera control(pan/tilt). It has also become possible to provide additional services like remote emergency warning broadcasting with just Internet Protocol (IP). However, because of the structural problems of IP, these changes have also brought about the threat of hacking of CCTV monitoring systems. In this study, we propose a methode to optimize network management by examining cases of enhancement of operational efficiency and security by improving the structure of CCTV monitoring network.

A Study on UCC and Information Security for Personal Image Contents Based on CCTV-UCC Interconnected with Smart-phone and Mobile Web

  • Cho, Seongsoo;Lee, Soowook
    • International Journal of Internet, Broadcasting and Communication
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    • 제7권2호
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    • pp.56-64
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    • 2015
  • The personal image information compiled through closed-circuit television (CCTV) will be open to the internet with the technology such as Long-Tail, Mash-Up, Collective Intelligence, Tagging, Open Application Programming Interface (Open-API), Syndication, Podcasting and Asynchronous JavaScript and XML (AJAX). The movie User Created Contents (UCC) connected to the internet with the skill of web 2.0 has the effects of abuse and threat without precedent. The purpose of this research is to develop the institutional and technological method to reduce these effects. As a result of this research, in terms of technology this paper suggests Privacy Zone Masking, IP Filtering, Intrusion-detection System (IDS), Secure Sockets Layer (SSL), public key infrastructure (PKI), Hash and PDF Socket. While in terms of management this paper suggests Privacy Commons and Privacy Zone. Based on CCTV-UCC linked to the above network, the research regarding personal image information security is expected to aid in realizing insight and practical personal image information as a specific device in the following research.

준설토 이송고효율화를 위한 유동특성의 실험적 분석 (Experimental study on flow characteristics for the high efficiency transporting of the dredged soil)

  • 김유승;이명한;이수연
    • 한국지반신소재학회논문집
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    • 제15권1호
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    • pp.71-81
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    • 2016
  • 준설토 이송 시 윤활층에 전자기장을 인가하여 이송 동력을 절감하고, 송토량을 증가시키는 연구의 일환으로, 이런 전자기장 장치의 실제 적용성을 검증하고자 실현장 8.5km의 이송거리의 준설현장에 전자기장 장치를 설치하여 그 효과를 검증하였다. 이송 유속에 관계되는 운전 조건 및 토질상태와 유동상태를 모니터링하고, 획득한 데이터를 송토량과 동력 사이의 관계로 정리하여 전자기장 인가 후 약 30%의 동력대비 이송량 증가가 있음을 확인하였고, 이를 통해 전자기장 인가가 준설토 이송 시 동력절감에 효과가 있음을 확인하였다.

멀티미디어와 RFID 등 IT를 활용한 지능형 타워크레인 개발 기초연구 (A basic study on the development of intelligent tower crane using IT)

  • 한용우;조훈희;이유섭;강태경;김종선
    • 한국건설관리학회:학술대회논문집
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    • 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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    • pp.625-628
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    • 2004
  • 타워크레인은 최근 증가되고 있는 고층 건축물의 시공에 핵심적인 장비임에도 불구하고, 지난 수십년간 이를 개선하기 위한 연구가 매우 부족하였다. 본 연구는 기존의 T형 타워크레인에 머신비전, RFID 및 GPS 기술 등을 접목한 지능형 타워크레인 개발 Framework을 제시하고, 제시된 Framework의 하위 모듈인 머신비젼 모듈의 프로토타입을 개발하였다. 머신비전 모듈은 CCTV와 LCD 모니터를 이용하여 현장 및 자재관련 멀티미디어 정보를 크레인 운전원과 현장 자업자가 실시간으로 공유학 수 있으므로 작업 생산성과 안전성을 의게 향상시킬 수 있을 것으로 기대된다.

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뇌보호설비용 인하도선의 설치조건에 따른 전위상승 (Potential Rises of Down-conductor for Lightning Protection System according to Establishment Conditions)

  • 이복희;강성만;이승칠;이동문;안창환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1724-1726
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    • 2001
  • This paper deals with the characteristics of the potential rises of down-conductor due to lightning surge currents. Direct lightning strikes can cause high impulse currents to the lightning protection system(LPS) of a building. These high impulse currents have the front time as short as 1[${\mu}s$]. In this case, the induced voltages caused in a closed circuit inside the building can be very high and cause damage or submit people to electric hazard. So, the LPS has to be designed to ensure safety condition to person and acceptable levels of induced voltages to the electrical and electronic equipments. The results of the potential rises related to the bonding conditions between the grounding conductor and metal raceway and the type of down-conductors are introduced.

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$TiO_2$ 나노 입자의 중간 전극을 이용한 직렬 적층형 유기 태양 전지 (Solution-processed Polymer Tandem Cells Using Nano Crystalline $TiO_2$ Interlayer)

  • 정원석;주병권;고민재;박남규;김경곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.444-444
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    • 2008
  • For the polymer tandem cell, simple and advantaged solution-based method to electron transport intermediate layer is presented which are composed $TiO_2$ nanoparticles. Device were based on a regioregular Poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl $C_{61}$ butyric acid methyl ester($PC_{60}BM$) blend as a donor and acceptor bulk-heterojunction. For the middle electrode interlayer, the $TiO_2$ nanoparticles were well dispersed in ethanol solution and formed thin layer on the P3HT:PCBM charge separation layer by spin coating. The layer serves as the electron transport layer and divides the polymer tandem solar cell. The open-circuit voltage (Voc) for the polymer tandem solar cells was closed to the sum of those of individual cells.

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