• Title/Summary/Keyword: flow-feedback

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고진동 운송계에서의 정밀 압력제어 장치의 설계 및 성능실험

  • 장원익;장기호;정기로;이종현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.237-242
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    • 1993
  • In the cluster tool, it is necessary to precisely control the vacuum pressure for the wafer transportation between transport module and cassette or process with the range of 10 $^{-4}$ to 5*10 $^{-5}$ torr. So we have designed the pressure control system for the transport module of the cluster tool and have evaluated its performance. Digital PID is utilized with the weighted sum of both three previous errors and one current error. The feedback signal is put into the nitrgen mass flow controller using the transport module controller. This pressure control system can prevent the transport module from the particle generation and backstreaming of hazardous process gases of the process chamber.

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Trends on Human/Robot Interface Research (휴먼/로봇 인터페이스 연구동향 분석)

  • Im, Chang-Ju;Im, Chi-Hwan
    • Journal of the Ergonomics Society of Korea
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    • v.21 no.2
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    • pp.101-111
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    • 2002
  • An intelligent robot, which has been developed recently, is no more a conventional robot widely known as an industrial robot. It is a computer system embedded in a machine and utilizes the machine as a medium not only for the communication between the human and the computer but also for the physical interaction among the human, the computer and their environment. Recent advances in computer technology have made it possible to create several of new types of human-computer interaction which are realized by utilizing intelligent machines. There is a continuing need for better understanding of how to design human/robot interface(HRI) to make for a more natural and efficient flow of information and feedback between robot systems and their users in both directions. In this paper, we explain the concept and the scope of HRI and review the current research trends of domestic and foreign HRL. The recommended research directions in the near future are also discussed based upon a comparative study of domestic and foreign HRI technology.

Congestion Control for the ABR Service of ATM networks with Multiple Congested Nodes and Multicast Connections (다수의 혼잡 노드와 멀티개스트 연결을 가지는 비동기 전송망의 ABR 서비스에 대한 혼잡 제어)

  • Nho, Ji-Myong;Lim, Jong-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.8
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    • pp.629-637
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    • 2000
  • Unbalance between user requirements and insufficient network resources makes a congestion. In the future since the communication networks will have very heavy traffic congestion will be more serious. The ATM networks was recommended to support the B-ISDN service for the future multimedia communication. In thie sense of congestion avoidance and recovery the ABR service category in ATM networks allows the feedback flow control mechanism to dynamically allocate the idle bandwidth of the network to users fairly and to control the network congestion rapidly In this paper we introduce a congestion control scheme using systematical approach to confirm robust stability with respect to unknown round trip delay for the network which has both unicast and multicast connections.

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Effects of mud-flap parameters on aeroacoustic noise generation inside high-speed trains (풍동을 이용한 고속열차 머드플랩 형상변경에 따른 공력소음 특성 분석)

  • Ryu, Ji-Myung;Park, Jun-Hong;Park, Ki-Hyoung;Song, Si-Mon;Choi, Sung-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.469-472
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    • 2007
  • Aeroacoustic sound induced from inter-couch spacing is an important contributor to interior noise generation for high speed trains. Especially the open space between mud-flap has significant impact from flow-structure interactions. To understand noise generation mechanism, experiments were performed using the wind tunnel. To find mud-flap parameters for minimal noise generations the various shape of the mud-flap was installed and its effects on the wall-pressure generation were investigated.

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Indicated and Load Torque Estimation of SI-Engine using Cylinder Pressure Sensor (실린더 압력센서를 사용한 가솔린 엔진의 도시토크와 부하토크의 추정)

  • 백종탁;박승범;선우명호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.1-6
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    • 2003
  • The torque is an important measure that represents the performance of a particular engine. Furthermore the information of engine torque can be used as a primary feedback parameter in modem engine management system. In this paper, a methodology is proposed for torque estimation of SI-engine. Since the proposed method uses cylinder pressure sensor, the torque can be estimated in a simple manner. The indicated torque is estimated from the peak pressure and its location, and the load torque is observed by the state observer based on the estimated indicated torque. The proposed method is accurate and robust against the variations that affect the torque production such as spark timing, mass air flow and others. This torque estimation method may be an alternative solution to the use of engine torque maps in a modem torque-based engine management system.

A study on EPD(End Point Detection) controller on plasma teaching process (플라즈마 식각공정에서의 EPD(End Point Detection) 제어기에 관한 연구)

  • 최순혁;차상엽;이종민;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.415-418
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    • 1996
  • Etching Process, one of the most important process in semiconductor fabrication, has input control part of which components are pressure, gas flow, RF power and etc., and plasma gas which is complex and not exactly understood is used to etch wafer in etching chamber. So this process has not real-time feedback controller based on input-output relation, then it uses EPD(End Point Detection) signal to determine when to start or when to stop etching. Various type EPD controller control etching process using EPD signal obtained from optical intensity of etching chamber. In development EPD controller we concentrate on compensation of this signal intensity and setting the relative signal magnitude at first of etching. We compensate signal intensity using neural network learning method and set the relative signal magnitude using fuzzy inference method. Potential of this method which improves EPD system capability is proved by experiences.

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A Customization of Web Contents : The Case of Kookmin Interned Banking eCRM (고객 맞춤 웹 컨텐츠 : 국민은행 인터넷뱅킹의 eCRM 사례)

  • 함유근;윤태주
    • The Journal of Information Technology and Database
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    • v.8 no.2
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    • pp.1-15
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    • 2001
  • In trying to bring about online CRM(customer relationship management), companies have paid much attention to eCRM. The key of eCRM is a recommendation system, which is being used by E-commerce sites to find products to purchase. To maintain a constant flow of marketing information and feedback it is important to staying in touch with customers. In this respect, eCRM becomes a serious business tool for sales activities. In this article we present tee case of Kookmin Internet banking eCRM welch is one of the first examples of implementing eCRM in commercial web site in Korea. We examine how Kookmin Internet banking develops eCRM and how it provides customized services to customers. We also explore the role of eCRM in Internet banking and the level of personalization technology used in Kookmin eCRM case.

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Development of device measuring very high torque via torque arm with attached load cells (로드셀과 토크암을 이용한 대용량 토크 측정장치 개발에 관한 연구)

  • Lee, Y.B.;Han, S.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.7 no.1
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    • pp.6-10
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    • 2010
  • A measurement of very high torque for track drive unit in construction equipment is usually in difficulties due to the requirement of a torque meter with high capacity, and the limitation of geometry for an experimental set-up. To improve the troublesome problem, a new device was proposed, where a torque transmitted through the torque arm can be measured by load cells attached at each torque arm. The experimental set-up of the new device was carried out in order to measure the torque values for a mechanical feedback type planetary gear box, in which the power flow circulates itself in a closed-loop. The new device enables to measure torque values of 60,000Nm. Additionally, the measured values were estimated statistically in the aspect of their repeatability and reproducibility, so that an acceptable behaviour as a measuring device can be confirmed.

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An optimization of synchronous pipeline design for IP-based H.264 decoder design (IP기반 H.264 디코더 설계를 위한 동기화 파이프라인 최적화)

  • Ko, Byung-Soo;Kong, Jin-Hyeung
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.407-408
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    • 2008
  • This paper presents a synchronous pipeline design for IP-based H.264 decoding system. The first optimization for pipelining aims at efficiently resolving the data dependency due to motion compensation/intra prediction feedback data flow in H.264 decoder. The second one would enhance the efficiency of execution per each pipelining stage to explore the optimized latency and stage number. Thus, the 3 stage pipeline of CAVLD&ITQ|MC/IP&Rec.|DF is obtained to yield the best throughput and implementation. In experiments, it is found that the synchronous pipelined H.264 decoding system, based on existing IPs, could deal with Full HD video at 125.34MHz, in real time.

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Theoretical and Experimental Study on Airfoil Singing (날개 명음소음에 관한 이론 및 실험 연구)

  • Ahn, Byoung-Kwon;Kim, Jong-Hyun;Choi, Jong-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.04a
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    • pp.476-476
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    • 2009
  • Periodic vortex separations generate periodic vertical forces acting on a trailing edge of an airfoil. When a natural frequency of the trailing edge of the airfoil is close to a vortex shedding frequency, an amplitude of the edge oscillation becomes maximal; it makes intensive noise called singing. Motion of the trailing edge may also feedback to the vortex shedding so that self-sustained oscillation appear, and a resonant frequency is locked in some interval of the speed of the incident flow. In this study, a theoretical model is proposed and applied for modeling an airfoil singing. Results are compared with experimental measurements which are carried out in an anechoic wind tunnel.

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