• Title/Summary/Keyword: ERF

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Fundamental Study on Performance Experiment of ER Clutch (ER클러치의 성능실험에 관한 기초적 연구)

  • 김도태;장성철;염만오;김태형
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.04a
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    • pp.66-71
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    • 2001
  • In this work, an ER clutch has been constructed and its characteristics have been evaluated by adapting an electro-rheological fluid(ERF) as an operating medium. ER fluids are suspensions which show an abrupt increase in rheological properties under electric fields. An ER clutch system using ER fluid is a new conception device because an apparent viscosity of ER fluid can be changed by apply an electric field. As a first, Bingham properties of ER fluids are experimentally distilled as a function of electric field. We use the disk type ER clutch in which the ER fluid fills the annular space between a pair of coaxial disk electrodes and experiment results show that the measured revolution per minute was increased with the increase of the electric field. The ER fluid used in the present study consists of weight fraction 35% in zeolite suspended silicone oil.

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Experimental Study on Flow Characteristics of ERF Between Two Parallel-Plate Electrodes by using PIV Technique (평행평판 전극사이에서 PIV 기법을 이용한 ER 유체의 유동특성에 관한 실험적 연구)

  • Chang Tae-Hyun;Chang Ki-Won
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.103-106
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    • 2003
  • An experimental investigation was peformed to study the characteristics of ER(Electro-Rheological) fluid water flow in a horizontal rectangular tube with or without D.C volatage. To determine some characteristics of the ER flow, 2D PIV(Particle Image Velocimetry) technique is employed for velocity measurement. This research found the mean velocity distribution with 0 kV/mm, 1.0kV/mm and 1.5kV/mm for Re = 0, 0.62, 1.29 and 2.26. When the strength of the electric field increased, the claster of ERF are clearly strong along the test tube and the flow rate decreased.

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ANFIS Intelligence Control of a Semi-Active Suspension System (반능동 현가장치의 ANFIS 지능제어)

  • 이육형;박명관
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.144-147
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    • 2000
  • In this paper, ANFIS intelligence control of a semi-active suspension system is investigated. The strength of the ER damper is controlled by a high voltage power supply. This paper deals with a two-degree-of-freedom suspension using the damper with ERF for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using passive and ANFlS control method. Computer simulation results show that the semi-active suspension with ERF damper has good performances of ride quality

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A Study on the Development of Nuclear Safety Parameter Display System for Korean Nuclear Power Plants (한국원전의 SPDS 개발에 관한 연구)

  • Kim, Dong-Hoon;Moon, Byung-Soo;Kim, Jae-Hee
    • Nuclear Engineering and Technology
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    • v.19 no.1
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    • pp.42-50
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    • 1987
  • Through a project "Development of Nuclear Safety Parameter Monitoring System", a nuclear data link system was established between Kori nuclear unit 2 and Nuclear Safety Center. We present in this paper the selected parameter sets, a description of the developed pseudo-network software and the functional descriptions of the equipments involved. We also include the conceptual design of the Kori four unit ERF/SPDS system, along with the localization direction for the related software and hardware. hardware.

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An Experimental Study on Flow Characteristics of ERF Between Two Parallel-Plate Electrodes by Using PIV Technique

  • Chang, Tae-Hyun;Jang, Sung-Cheol
    • Journal of Mechanical Science and Technology
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    • v.18 no.10
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    • pp.1763-1771
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    • 2004
  • An experimental investigation was performed to study the characteristics of ER (Electro-Rheological) fluid flow in a horizontal rectangular tube with or without D. C voltage. To determine some characteristics of the ER flow, 2D PIV(Particle Image Velocimetry) technique was employed for velocity measurements. This research found the mean velocity distributions with 0kV /mm, l.0kV /mm and l.5kV /mm for Re=0, 0.62, 1.29 and 2.26. When the strength of the electric field increased, the cluster of ERF was clearly strong along the test tube and the flow rate decreased. The present results will contribute to the economical and compact design of ER fluids system.

Experimental Study on Flow Characteristics of ERF by using PIV Technique (PIV 기법을 이용한 ER 유체의 유동특성에 관한 실험적 연구)

  • 장태현
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.1
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    • pp.116-123
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    • 2004
  • An experimental investigation was performed to study the characteristics of ER (Electro-Rheological) fluid flow in a horizontal rectangular tube with or without D.C volatage. To determine some characteristics of the ER flow. 2D PIV(Particle Image Velocimetry) technique is employed for velocity measurement. This research found the mean velocity distribution with 0 kV/mm. 1.0kV/mm and 1 5kV/mm for Re=0, 0.62, 1.29 and 2.26. When the strength of the electric field increased. the claster of ERF are clearly strong along the test tube and the flow rate decreased.

Skyhook Control of a Semi-Active ER Damper (반능동 ER댐퍼의 스카이훅 제어)

  • Lee, Yuk-Hyeong;Park, Myeong-Gwan
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.1
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    • pp.56-62
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    • 2001
  • In this paper, skyhook control of a semi-active ER(Electro-Rheological) damper is investigated. The strength of the ER damper is controlled by a high voltage power supply. This paper deals with a two-degree-of-freedom suspension using the damper with ERF for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using skyhook and Linear Quadratic Regulator(LQR) optimal control method. Computer simulation and experimental results show that the semi-active suspension with ERF damper has good performances of ride quality.

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Viscoelastic properties of electrorheological fluids (전기유변유체의 점탄성 특성에 관한연구)

  • Choe, Yun-Dae;Kim, Sang-Guk
    • Korean Journal of Materials Research
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    • v.2 no.3
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    • pp.220-227
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    • 1992
  • Electrorheological(ER) fluid's storage shear modulus(G') and loss factor(${\eta}$) have been directly measured using small amplitude forced oscillating rheometer as a function of oscillating frequency, strain amplitude and applied electric field. Two types of experiment were performed , (a) frequency sweep and (b) amplitude sweep. Two kinds of sample were employed for this experiment ; cornstarch particles in corn oil and zeolite particles in silicone oil. The storage shear modulus was a strong function of driving frequency. Generally, the modulus increased with driving frequency. On the other hand, the loss factor was not well behaved as storage modulus, but as the driving frequency increases the loss factor slightly decreases was the trend of the material's characteristics. Also the modulus was a strong function of strain amplitude. Generally, modulus decreased with increasing strain, but loss factor increases slightly with increasing strain amplitude. For G', cornstarch in corn oil ER fluid has higher values than zeolite based fluid as we increased applied electric field. On the other hand, zeolite based fluid has higher values for ${\eta}$. There is a reasonable agreement between theoretical calculation and experiment.

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Die Rolle des minimalen Wortes $f\"{u}r$ die prosodische Struktur des Deutschen (독일어 운율구조에서 최소단어의 역할)

  • Yu Si-Taek
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.5
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    • pp.67-89
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    • 2002
  • Die meisten $W\"{o}rter$ im Deutschen, die zur lexikalichen Hauptkategorie $geh\"{o}ren,\;erf\"{u}llen$ die prosodischen Bedingungen, class sie ein phonologisches Wort bilden und class ein phonologisches Wort zumindest aus zwei Moren besteht. In dieser Arbeit wird gezeigt, welche Konsequenzen diese Constraints $f\"{u}r$ die prosodische Gestalt der deutschen $W\"{o}rter$ haben. Eine davon bezieht sich auf das $Ph\"{a}nomen$, das in der Literatur als 'minimales Wort' bekannt ist. Die distributionellen $Beschr\"{a}nkungen$ eines ungespannten kurzen Vokals im Deutschen sind darauf $Zur\"{u}ckzuf\"{u}hren$, class ein prosodisches Wort mindestens zwei Moren enthalten muss. Die Forderung nach einem minimalen Wort wirft aber die Frage, warum ein Stamm wie feige eine zweisilbige Struktur CVCV mit einer finalen Schwasilbe aufweisen, ein Stamm wie reif dagegen eine einsilbige Struktur eve. Allein die Forderung nach einem zweimorigen prosodischen Wort wurde auch eine ungrammatische Form wie feig $erf\"{u}llen$. Bei Formen wie feige ist festzustellen, dass das Constraint IDENT-IO [voiced] wichtiger als das Constraint ist, das einen einsilbigen Stamm verlangt. Eine Analyse, in der die finale Schwa-Silbe in einem CVCV-Stamm als ein stammbildendes Element oder Pseudosuffix aufgefasst wird, kann diese Interaktion zwischen Constraint nicht erfassen. Im Vergleich dazu zeigen die zweisilben Flexionsformen, bei denen Schwa-Silben als ein echtes Suffix fungieren, dass das Constraint 'Realisiere Morphem' nur dann verletzt werden kann, wenn es zur $Erf\"{u}llung\;des\;h\"{o}her$ rangierten Constraints OCP(nucleus) dient. Dieses Constraint ist seinerseits nur dann verletzbar, wenn damit das $h\"{o}here$ Constraint Coda-Cond erfullt werden kann.

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Analysis of Observation Characteristics by Cognitive Style : MEG Study (인지양식에 따른 관찰 특성 분석 : MEG 연구)

  • Yang, Il-Ho;Lee, Soon-Joo;Kim, Eun-Ae;Lee, So-Ree;Kwon, Suk-Won
    • Journal of The Korean Association For Science Education
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    • v.30 no.8
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    • pp.1097-1109
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    • 2010
  • The purpose of this study is to analyze the ERF components patterns of observers who have different cognitive styles using magneto-encephalography (MEG). The task was developed based on the CSA (Cognitive Style Analysis) program. Eight right-handed, healthy male college students participated in voluntarily. To investigate college students' ERF components during the task, an MEG system with block design was used to measure magnetic signals in their brains. For examining the observation characteristic by cognitive style, MEG ERF components were analyzed. As a result, four ERF components (M1, M2, M3, M4) were observed. Through the results of this study, the reason for different observation characteristics by cognitive styles was verified in the neurophysiological methods. This study will have implications to establish theories on scientific observation and cognitive styles.