• 제목/요약/키워드: ERF

검색결과 86건 처리시간 0.026초

ER브레이크 작동기를 이용한 능동 장력 제어 (Active Tension Control Using an ER Brake Actuator)

  • Park, S.B.;Kim, G.W.;Cheong, C.C.
    • 한국정밀공학회지
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    • 제13권8호
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    • pp.102-111
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    • 1996
  • This paper presents a proof-of-concept investigation on an active tension control using an ER (electro-rheological) brake actuator. Firstly, an ERF (electro-rheological fluid) which has an inherent reversible feature from Newtonian fluid to Bingham fluid upon applying an electric field is composed, and its property is tested to obtain intrinsic parameters of the Bingham model. An appropriate size of the ER brake is manufactured on the basis of the Bingham model, and dynamic characteristics of the brake are experimentally identified. After formulating a governing equation of motion of the tension control system, a sliding mode controller is designed to achieve a certain desired level of tension. Both simulation and experimental works are undertaken in order to demonstrate the efficiency and feasibility of the proposed active tension control method.

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ER댐퍼를 이용한 차량의 진동제어 (Vibration Control of a Vehicle using ER Damper)

  • 주동우;이육형;박명관
    • 한국정밀공학회지
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    • 제16권5호통권98호
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    • pp.104-111
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    • 1999
  • A semi-active suspension system for a vehicle using an Electrorheological Fluid damper has been studied. Apparent viscosity of ERF(Electrorheological Fluid) can be changed rapidly by applying electric field. The damping force of ER damper can be selectively controlled by employing electric field to the ER fluid domain. This paper deals with a two-degree-of-freedom suspension using the ER damper for a quarter car model. An intelligent control method using fuzzy control with genetic algorithm has been employed to control the damping force of the ER damper. The GA designs the optimal structure and performance of Fuzzy Net Controller having hybrid structure. The designed fuzzy net controller has been compared with the skyhook type controller for a quarter car model. The computer simulation results show that the semi-active suspension with ER damper has a good performance in the sense of ride quality with less vibration for ground vehicle.

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ERF를 이용한 유압제어밸브의 특성실험 (Characteristic Experiment of a Hydraulic Control Valve by Using Electro-Rheological Fluid)

  • 김동수;박재범;장성철
    • 연구논문집
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    • 통권30호
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    • pp.93-99
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    • 2000
  • Electro-Rheological(ER) fluids change their apparent viscosity according to the electric field strength. The electrical and rheological properties of zeolite based the ER fluids were reported. The electric field dependent yield stress are obtained from experimental investigation on the Bingham property of the ER fluid. Using ER fluids, it is possible to directly interface between electric drop and flow rate of the ER fluid was hydraulic control valve measured under application of an electric field. The purpose of the present study is pressure drop measurement of an ER valve by using strain gage. The performance characteristics of the valve system are evalusted in terms of pressrue fixed with respect to the intensity of employed electric fields and flow rates. As a result, it is esperimentally confirmed that pressure control valve using ER fluids applicable to use in hydraulic power systems.

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STRUCTURE OF IDEMPOTENTS IN POLYNOMIAL RINGS AND MATRIX RINGS

  • Juan Huang;Tai Keun Kwak;Yang Lee;Zhelin Piao
    • 대한수학회보
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    • 제60권5호
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    • pp.1321-1334
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    • 2023
  • An idempotent e of a ring R is called right (resp., left) semicentral if er = ere (resp., re = ere) for any r ∈ R, and an idempotent e of R∖{0, 1} will be called right (resp., left) quasicentral provided that for any r ∈ R, there exists an idempotent f = f(e, r) ∈ R∖{0, 1} such that er = erf (resp., re = fre). We show the whole shapes of idempotents and right (left) semicentral idempotents of upper triangular matrix rings and polynomial rings. We next prove that every nontrivial idempotent of the n by n full matrix ring over a principal ideal domain is right and left quasicentral and, applying this result, we can find many right (left) quasicentral idempotents but not right (left) semicentral.

외국어 교육인가 방해인가? - 한국 외국어 교육관행을 분석하며

  • 박진길
    • 한국독어학회지:독어학
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    • 제4집
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    • pp.373-394
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    • 2001
  • Bis jetzt haben wir $haupts\"{a}chlich$ verschiedene Probleme an Ort und Stelle des Fremdsprachunterrichts analysiert, und zwar: (a) den > Spracherwerbsmechanismus < die >SMQ< und den > auf jeweilige (Fremd)sprache fuhrenden Unterrieht<, die drei Lehr- u. Lernfaktoren des Spraeherwerbs, (b) den Lehr- u. $Lemproze\ss$ der Muttersprache, (c) die 5 Fertigkeitsaufgaben und (d) einige Prinzipien und ihre $Ma{\ss}nahmen$ der Sprachlehr- u. -lernmethode Aus diesen Grundlagen werden die folgenden Ergebnisse be- sonders hervorgebracht werden: (d) Das Hauptziel des Fremdspraehunterrichts soll/muss man darin finden, $zun\"{a}chst$ die >SMQ< zu $erf\"{u}llen$, die etwa 1000 $\"{A}u{\ss}erungen/S\"{a}tzen$ entspricht, um perfekt zu sprechen. (e) Alle Menschen kommen ausnahmslos genetisch mit dem >Spracherwerbsmechanismus< zur Welt, der alles Sprachmaterial grammatisch/systematisch aufnimmt. (f) Aus diesem Grund darf man den $Anf\"{a}nger$ keine Gramma -tik lehren, bis er perfekt sprechen kann, weil er als Mensch schon alles grammatisch lernen kann. (g) Stattdessen lohnt es sich, im Unterricht nur auf jeweilige Fremdsprache zu sprechen, zu schreiben und zu $erkl\"{a}ren$, d.h. den auf jeweilige Sprache $f\"{u}hrenden$ Unterricht intensiv zu hal- ten, was auch beim Mutterspracherwerb immer der Fall ist. (h) Es ist sehr ratsam $f\"{u}r$ uns, die Lehr- u. Lernmethode im Fall des Mutterspracherwerbs als Unterrichtsmodell dynamisch anzuwenden, weil sie uns immer den $100\%$ Erfolg geschenkt hat. (i) Im Alltag braucht man $st\"{a}ndig$ den Ansprecher/die -in (z.B. im Fernseh/ durch Internet) nachzuahmen, und zwar die Sprechweise, die Gestik bzw. Mimik usw. (j) Es soll/muss streng verboten werden, im Fremdsprach- unterricht auf Muttersprache zu sprechen, weil es mit der Fremd -sprachausbildung, d.h. mit der $Erf\"{u}llung$ von >SMQ< gar nicht zu tun hat, sondern eine Art Betrug sein $k\"{o}nnte$, soweit das folgende koreanische Sprichwort noch gilt: Der Apfel $f\"{a}llt$ nicht weit vom Stamm. (k) Ohne Reformierung des konventionellen Fremdsprachunter -richts, $100\%\;Mi{\ss}lingen$ hinnehmen zu $m\"{u}ssen$, kann man nichts weiter machen. Denn er $st\"{o}rt$ uns das auf jeweilige Sprache bezo -gene Denken. Z.B. die sinnlose Grammatik, auf Muttersprache zu sprechen, die unmittelbare $\"{U}bersetzung$ usw. sind dessen $R\"{a}delsf\"{u}hrer.\;Alle\;L\"{a}nder\;besch\"{a}ftigen\;sich\;st\"{a}ndig\;damit,\;ihre\;M\"{o}glichkeit$ in der harten Existenzkonkurrenz durch die Bildungsreform auszu -gleichen. Denn die Ausbildung der Hochtechnologie im 21. Jh. braucht notwendig die $Fremdsprachf\"{a}higkeit$ als ihre Grundlage. Ohne Selbstreformierung $k\"{o}nnten$ wir als Fremdsprachlehrer/-pro -fessoren - auf Koreanisch sprechend - weiter den Fremdsprach -unterricht halten?

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청청/낙동 배가반수체 집단에서 QTL을 통한 출수기와 수량관련 유전자좌 분석 (Characterization of Heading- and Yield-related Gene Loci in the Cheongcheong/Nagdong Doubled Haploid Line using Rice QTLs)

  • 장윤희;박재령;김경민
    • 한국작물학회지
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    • 제64권1호
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    • pp.1-17
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    • 2019
  • 본 연구는 2017년 CNDH 계통을 이용하여 출수기와 수량을 QTL 조사하여 다음과 같은 결과를 가졌다. 1. 도수분포표에서 QHD, QTPW, QM, QTGW, QY는 정규분포를 이루고 있었다. 2. 출수기 관련 QTLs은 총 1개가 잡혔고, 수량관련 QTLs은 총 9개가 잡혔다. QHD에서는 LOD 2.85가 가장 컸고, QTPW에서는 5.39, QM에서는 3.92, QTGW에서는 4.80, QY에서는 3.7이 가장 컸다. 3. 유전자 분석을 통해, 2, 3, 7, 8, 10번 염색체에서 총58개의 후보유전자를 찾았다. 이 중 수량요소인 QM에서 Rcd1 protein, OsERF3 유전자, QTGW에서 MtN3, Zinc finger protein 유전자, QY에서 OsNAC3 protein 유전자를 발견하였다. 4. 본 연구를 통해 발견된 CNDH 계통 내의 수분함량, 천립중, 수량에 관련된 유전자의 존재여부를 찾아낸다면 조생종, 수중형에 가까운 품종을 개발하는 데 기초자료로 이용될 수 있을 것이라 판단된다.

New Concept of Stiffness Improvement in Paper and Board

  • Seo, Yung B.
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2001년도 추계학술발표논문집
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    • pp.168-182
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    • 2001
  • A new concept of stock preparation for the increase of bending stiffness in paper and board was proposed. The 'stiff' fibers, which were mechanically not treated or treated slightly to remove fiber curls, were combined with extensively refined fibers (ERF) to produce higher stiffness papers than those where the whole fibers were refined. The combination of 'stiff' fibers and extensively refined fibers produced higher stiffness at the same tensile strength than the control furnish, in which all the fibers are refined together. In this concept, the fibers from recycled papers could be as much useful as the virgin fibers as long as they are stiff enough or they can produce highly bondable fiber fractions by extensive refining. Use of the concept in real paper mill needs considerations such as increase of refining energy, slower drainage, and added drying burden, but savings of wood fibers, utilization of more recycled fibers, and increase of physical properties may offset the negative concerns. The success of this concept implementation in mills, therefore, depends on the wood fiber market around the mills and the proper decision making for the papermakers about how to apply this concept.

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여성어의 수용적 태도 (Positive Sprechhandlung der Frauen im $Gespr\"{a}chstext$)

  • 김홍자
    • 한국독어학회지:독어학
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    • 제4집
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    • pp.205-240
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    • 2001
  • Viele Feministinnen glauben, $da{\ss}\;unvollst\"{a}ndige\;S\"{a}tze$ ein typisches Merkmal $f\"{u}r$ einen spezifisch weiblichen Stil sind. An dieser Stelle soll lediglich ein kurzer Uberblick $\"{u}ber$ die wesentlichen Erscheinungsformen der geschlechtsspezifischen sprachlichen Variation gegeben werden. Zu den universellen Erscheinungen, die in allen Sprachen einen formalen Ausdruck finden, $k\"{o}nnen$ die kommunikativen Rollen $geh\"{o}ren$, die Personen in sprachlichen Interaktionen einnehmen. Im Rahmen der Linguistik sind nicht nur die expliziten und indexikalischen sprachlichen Mittel von Interesse, sondern auch deren kommunikative Signifikanz, da die $oberfl\"{a}chenspra­chliche$ Realisierung dieser auf die Geschlechtsidentitat verweisenden sprachlichen Indikatoren, deren Problematisierung hinsichtlich der Geschlechterdifferenzen signalisiert. Referenzen auf die $Berufsidentit\"{a}t$ hingegen verweisen auf das soziokulturelle Konstrukt der betreffenden Berufsfelder, wobei sie diese jedoch nur spezifizieren. 'Unter thematisch-inhaltlichen Gesichtspunkten haben sich diese Erwartungen $erf\"{u}llt$, da die Teilnehmerinnen zum Teil von sehr $pers\"{o}nlichen$ Erfahrungen berichteten. In dieser Arbeit hat es sich gezeigt, wie sich gesellschaftliche Diskriminierung von Frauen im Sprachgebrauch spiegelt, indem die Frauensprache untersucht wird: Unterschiedliches $Gespr\"{a}chs-und$ Sprachverhalten von $M\"{a}nnern$ und Frauen. Die sprachliche Gleichbehandlung von Frauen und $M\"{a}nnem\;mu\ss$ auf der aufrichtigen Erkenntnis von der $ver\"{a}nderten$ sozialen Rolle der Frauen $gegr\"{u}ndet$ werden.

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Plasticity of rice to water extremes: Farmers' genes to mechanisms

  • Bailey-Serres, Julia
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.5-5
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    • 2017
  • Too little and too much water due to climatic events is a significant cause of global food insecurity. Crops are less productive under water-limited conditions and all major crops, with the exception of rice (Oryza sativa), die within a few days of complete submergence. To complement our studies on genes such as SUB1A, (an ERF-VII transcription factor that provides robust submergence tolerance) and AG1 (a TREHALOSE 6-P PHOSPHATASE that promotes establishment of young seedlings underwater), we have retooled INTACT (${\underline{I}}solation$ of ${\underline{N}}uclei$ ${\underline{TA}}gged$ in specific ${\underline{C}}ell$ ${\underline{T}}ypes$) and TRAP (${\underline{T}}ranslating$ ${\underline{R}}ibosome$ ${\underline{A}}ffinity$ ${\underline{P}}urification$) for rice. These technologies enable us to follow dynamics in chromatin, nuclear pre-mRNAs and ribosome-bound mRNAs in meristems and diverse cell types. With these technologies we can better interpret responses to stresses and reestablishment of homeostasis. These include stress acclimation strategies involving changes in metabolism and development, such as dynamics in suberin deposition in sub-epidermal layers of roots that limit water loss under drought and oxygen escape during waterlogging. Our new data uncover dynamic and reversible regulation at multiple levels of gene regulation and provide new insights into processes of stress resilience. Supported by US NSF-PGRP Plasticity (IOS-1238243), Secretome (IOS-1546879) and REU (DBI-146129) grants.

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Molecular Cloning, Phylogenetic Analysis, Expressional Profiling and In Vitro Studies of TINY2 from Arabidopsis thaliana

  • Wei, Gang;Pan, Yi;Lei, Juan;Zhu, Yu-Xian
    • BMB Reports
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    • 제38권4호
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    • pp.440-446
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    • 2005
  • A cDNA that was rapidly induced upon abscisic acid, cold, drought, mechanical wounding and to a lesser extent, by high salinity treatment, was isolated from Arabidopsis seedlings. It was classified as DREB subfamily member based on multiple sequence alignment and phylogenetic characterization. Since it encoded a protein with a typical ERF/AP2 DNA-binding domain and was closely related to the TINY gene, we named it TINY2. Gel retardation assay revealed that TINY2 was able to form a specific complex with the previously characterized DRE element while showed only residual affinity to the GCC box. When fused to the GAL4 DNA-binding domain, either full-length or its C-terminus functioned effectively as a trans-activator in the yeast one-hybrid assay while its N-terminus was completely inactive. Our data indicate that TINY2 could be a new member of the AP2/EREBP transcription factor family involved in activation of down-stream genes in response to environmental stress.