• 제목/요약/키워드: focus control

검색결과 1,733건 처리시간 0.03초

Energy-Efficient Cooperative Medium Access Control (MAC) Protocol for Wireless Sensor Networks

  • Ahmed, Mohammad Helal Uddin;Hong, Choong-Seon
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(D)
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    • pp.267-268
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    • 2011
  • Recent research activities in cooperative communication focus on achieving energy efficiency and reliability. Relay selection strategy for cooperative communication improves the performance significantly. However, due to imbalance consumption of power, network might die earlier and more than 90% energy remains unused. In this paper, we provide a framework of an energy-efficient medium access control protocol that minimizes these problems and improves energy efficiency.

The Air Pollution Prevention and Control Division's Program within U.S. EPA's Office of Research and Development

  • Princiotta, Frank T.
    • 청정기술
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    • 제2권2호
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    • pp.30-41
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    • 1996
  • Air pollution problems are serious and present significant challenges to the engineering research community. EPA's engineering research programs have shifted from a primary focus on $SO_2$ and NOx pollution control to more complex and more difficult problems such as indoor air quality, air toxics, and global climate change. EPA research engineers are working closely with other research organizations in both the private sector and other federal research organizations to identify, evaluate, and develop cost-effective engineering solutions. The APPCE works closely with the EPA regulatory and regional offices to ensure that the best engineering information is utilized to formulate and implement the Agency's environmental protection program.

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Opto-Mechanical Detailed Design of the G-CLEF Flexure Control Camera

  • Jae Sok Oh;Chan Park;Kang-Min Kim;Heeyoung Oh;UeeJeong Jeong;Moo-Young Chun;Young Sam Yu;Sungho Lee;Jeong-Gyun Jang;Bi-Ho Jang;Sung-Joon Park;Jihun Kim;Yunjong Kim;Andrew Szentgyorgyi;Stuart McMuldroch;William Podgorski;Ian Evans;Mark Mueller;Alan Uomoto;Jeffrey Crane;Tyson Hare
    • 천문학회지
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    • 제56권2호
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    • pp.169-185
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    • 2023
  • The GMT-Consortium Large Earth Finder (G-CLEF) is the first instrument for the Giant Magellan Telescope (GMT). G-CLEF is a fiber feed, optical band echelle spectrograph that is capable of extremely precise radial velocity measurement. G-CLEF Flexure Control Camera (FCC) is included as a part in G-CLEF Front End Assembly (GCFEA), which monitors the field images focused on a fiber mirror to control the flexure and the focus errors within GCFEA. FCC consists of an optical bench on which five optical components are installed. The order of the optical train is: a collimator, neutral density filters, a focus analyzer, a reimager and a detector (Andor iKon-L 936 CCD camera). The collimator consists of a triplet lens and receives the beam reflected by a fiber mirror. The neutral density filters make it possible a broad range star brightness as a target or a guide. The focus analyzer is used to measure a focus offset. The reimager focuses the beam from the collimator onto the CCD detector focal plane. The detector module includes a linear translator and a field de-rotator. We performed thermoelastic stress analysis for lenses and their mounts to confirm the physical safety of the lens materials. We also conducted the global structure analysis for various gravitational orientations to verify the image stability requirement during the operation of the telescope and the instrument. In this article, we present the opto-mechanical detailed design of G-CLEF FCC and describe the consequence of the numerical finite element analyses for the design.

AGV의 분산제어를 위한 에이전트 기반의 제어시스템 (Agent-based control systemfordistributed control of AGVs)

  • 오승진;정무영
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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    • pp.1117-1123
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    • 2005
  • This paper deals with a new automated guided vehicle (AGV) control system for distributed control. Proposed AGV control system adapts the multi-agent technology. The system is composed of two types of controller: routing and order. The order controller is in charge of assignment of orders to AGVs. Through the bidding-based negotiation with routing controllers, the order controller assigns a new order to the proper AGV. The order controller announces order information to the routing controllers. Then the routing controllers generate a routing schedule for the order and make a bid according to the routing schedule. If the routing schedule conflicts with other AGV's one, the routing controller makes an alternative through negotiation with other routing controllers. The order controller finally evaluates bids and selects one. Each controller consists of a set of agents: negotiation agent, decision making agent and communication agent. We focus on the agent architecture and negotiation-based AGV scheduling algorithm. Proposed system is validated through an exemplary scenario.

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적응 퍼지-뉴로 제어기의 설계와 응용 (Design & application of adaptive fuzzy-neuro controllers)

  • 강경운;김용민;강훈;전홍태
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.710-717
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    • 1993
  • In this paper, we focus upon the design and applications of adaptive fuzzy-neuro controllers. An intelligent control system is proposed by exploiting the merits of two paradigms, a fuzzy logic controller and a neural network, assuming that we can modify in real time the consequential parts of the rulebase with adaptive learning, and that initial fuzzy control rules are established in a temporarily stable region. We choose the structure of fuzzy hypercubes for the fuzzy controller, and utilize the Perceptron learning rule in order to update the fuzzy control rules on-line with the output error. And, the effectiveness and the robustness of this intelligent controller are shown with application of the proposed adaptive fuzzy-neuro controller to control of the cart-pole system.

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Development of the Broadband PLC Home Controller using JINI Surrogate

  • Kim, Yong-Seok;Kim, Hee-Sun;Lee, Chang-Goo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1563-1567
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    • 2005
  • The Home network system means that information appliances, Home PCs, etc., using wired or wireless network method enable to control and share with peripheral devices such as internet, shared data, a scanner and a printer, and it is networking solution, which intelligent communication will be possible as the system which can do a remote control such as TV Set, refrigerators, air conditioners, DVD players, digital camcorders based on external network using an internet, a potable information terminal and a mobile phone whenever, wherever and freely. In this study, the home network interface solution is used one of the wired network standards, PLC (Power-Line Communication) technology, so we can construct of intelligent home network's home controller without re-build a network at home. On keeping with current waves of thought, we will focus on a home controller development with great interest which is enabled to do an effective managed control, applying intelligent home network technology which can be new paradigm like a cyber apartment.

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한국형 관제시스템을 위한 시스템 구조 (System Architecture for Korean Air Traffic Control System)

  • 이창호;신광식;정진하;정동석;박효달;최상방
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.1199-1200
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    • 2008
  • In this paper, we suggest a system architecture for korean air traffic control system through investigating a korean ARTS (Automated radar terminal system) and ACC (Area control center) system. We focus on designing a network architecture for supporting both an approaching control and an area control. This paper will be a base for developing korean air traffic control system by ourselves.

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산업용 다관절 로봇의 비주얼 피드백 제어에 관한 연구 (A Study on Visual Feedback Control of Industrial Articulated Robot)

  • 심병균;한성현
    • 한국기계가공학회지
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    • 제12권1호
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    • pp.35-42
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    • 2013
  • This paper proposes a new approach to the designed of visual feedback control system based on visual servoing method. The main focus of this paper is presented how it is effective to use many features for improving the accuracy of the visual feedback control of industrial articulated robot for assembling and inspection of parts. Some rank conditions, which relate the image Jacobian, and the control performance are derived. It is also proven that the accuracy is improved by increasing the number of features. The effectiveness of redundant features is verified by the real time experiments on a SCARA type robot(FARA) made in samsung electronics company.

Improved H.263+ Rate Control via Variable Frame Rate Adjustment and Hybrid I-frame Coding

  • 송환준
    • 한국통신학회논문지
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    • 제25권5A호
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    • pp.726-742
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    • 2000
  • A novel rte control algorithm consisting of two major components, i.e. a variable encoding frame rate method and a hybrid DCT/wavelet I-frame coding scheme, is proposed in this work for low bit rate video coding. Most existing rate control algorithms for low bit rate video focus on bit allocation at the macroblock level under a constant frame rate assumption. The proposed rate control algorithm is able to adjust the encoding frame rate at the expense of tolerable time-delay. Furthermore, an R-D optimized hybrid DCT/wavelet scheme is used for effective I-frame coding. The new rate-control algorithm attempts to achieve a good balance between spatial quality and temporal quality to enhance the overall human perceptual quality at low bit rates. It is demonstrated that the rate control algorithm achieves higher coding efficiency at low bit rates with a low additional computational cost. The variable frame rate method and hybrid I-frame coding scheme are compatible with the bi stream structure of H.263+.

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중첩의 정리를 이용한 PMSM의 센서리스 제어 (The study on the sensorless PMSM control using the superposition theory)

  • 박현주;박성준;김종달;손무헌;김규섭;이일천
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 학술대회 논문집 전문대학교육위원
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    • pp.120-126
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    • 2001
  • This paper presents a solution to control a PMSM(Permanent Magnet Synchronous Motor) without sensor. The control method is the presented superposition principle. This method of sensorless theory is very simple to compute estimated angle. The use of this system yields enhanced operations, fewer system components, lower system costs, efficient energy control system designs and increased efficiencies. A practical solution is described and its results are given in this study. The performance of a sensorless architecture allows an intelligent approach to reduce the complete system costs of digital motion control applications using the cheaper electrical sensorless motors. This paper deals with an overview of solutions in the sensorless PMSM control applications, whereby the focus will be the new sensorless controller and its applications.

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