• Title/Summary/Keyword: Dynamic Property

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Experimental Performance Analysis and Vibration Control of Commercial Vehicle Seat Suspension System Using ER Seat Damper (ER시트댐퍼를 사용한 상용차운전석의 실험적 성능해석 및 진동제어)

    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.3
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    • pp.7-13
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    • 1998
  • This paper presents a new concept of a commercial vehicle seat suspension system. The proposed suspension system features an ER(electro-rheological)damper which can produce continuously tunable damping forces by control elecric fields. A dynamic model of the ER damper is first achieved by incorporating Bingham property of the ER fluid, followed by the formulation of governing equations of motion for the suspension system The effectiveness of the proposed ER seat suspension system is evaluated by investigating vibration with respect to sinusoidal inputs.

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Development of 3-Axis Actuator for Active Tilt Compensation (틸트 구동형 엑추에이터의 개발)

  • 이강녕;박세준;이동주;박노철;조원익;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.226-233
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    • 2003
  • There are many researches going on to develop the information storage devices using Blue-ray disc and DVD as a demand for high-density information storage devices is highly increasing. This high-density information storage device requires a short-wave laser and objective lens of high numerical aperture set in fer its operation. And, that brings out rapid decrease of tilt tolerance. Therefore, it is necessary that an actuator should control tilt motions to get a stable signal. In this paper, a new mathematical form of 3-D.O.F coupled model is formulated and magnetic circuit in constraints is most effectively designed with the use of the moving coil type actuator in higher sensitivity. Further, this paper presents a tilt coil whose rotational center point is put on that of the lens through the variation of tilt coil and proposes a 3-axis actuator with high sensitivity improved in its dynamic property through its structure analysis.

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Study on Evaluation of Energy Efficiency Rating of the Buildings (건축물의 에너지효율등급 평가에 관한 연구)

  • Son, Won-Tug;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.15 no.3
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    • pp.65-69
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    • 2012
  • Since 2010, enhancement of the building energy efficiency and certification system and public office building should have been acquiring the first grade of Building Energy Efficiency. The Building Energy Efficiency Rating evaluation tool and Dynamic Analysis Energy simulation program for Building Energy Efficiency are widely used. The suitability to those programs have been discussed as a variety of programs have been used accordingly. In this study, evaluated the characteristic of Building Energy Efficiency Rating tool(ECO2) of the business building. At a result, the variables on the Weather Data, building Profile and building Load property in hourly between those Building Energy Efficiency evaluation tools have different.

A Semi-Active Suspension Using ER Fluids for a Commercial Vehicle Seat (ER 유체를 이용한 상용차 운전석의 반능동형 현가 장치)

  • 최정환;남무호;최승복;정재천
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.394-399
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    • 1997
  • This paper presents a new concept of a semi-active suspension system for a commercial vehicle seat. The proposed suspension system features an ER(electro-rheological) damper which can produce continuously tunable damping forces by control electric fields. A dynamic model of the ER damper is first achieved by incorporating Bingham property of the ER fluid, followed by the formulation of governing equations of motion for the suspension system. A sliding mode controller is then designed on the basis of the hyper-plane sliding mode scheme. The effectiveness of the proposed control system is evaluated by investigating control performance for vibration isolation.

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The Role of Compensation in Natural Resource Conflicts (자연자원분쟁에서 보상의 역할에 대한 연구)

  • Hong, Seonghoon
    • Environmental and Resource Economics Review
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    • v.11 no.1
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    • pp.31-55
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    • 2002
  • When landowners have private information about land value, compensation based on conservation value at the time of regulatory takings of land is impractical even though it generates an efficient outcome. No compensation rule to a landowner not only yields an inefficient outcome but also provides an ex ante pervasive incentive for the landowner to invest in lowering conservation value. An alternative rule of compensation based on the market value of the land provides ex ante incentives for landowner either to reduce conservation value or to increase it. Under the market value compensation rule, placing the burden of proof on landowner gives higher probability of conservation than placing it on regulator. Whether it is better to allure landowners to conserve by paying compensation with market value and placing the burden of proof on landowner through changes in the regulatory regime however depends on the magnitude of inefficiency, equity consideration and dynamic nature of property rights on environmental goods.

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Effects of ${\beta}$-Conglycinin and Glycinin on Thermal Gelation and Gel Properties of Soy Protein

  • Kang, Il-Jun;Lee, Young-Sook
    • Food Science and Biotechnology
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    • v.14 no.1
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    • pp.11-15
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    • 2005
  • Dynamic shear moduli of isolated soy protein solutions upon heating were measured to monitor gelation. Onsets of gelation coincide with onset temperatures of denaturation in glycinin and ${\beta}$-conglycinin solutions, whereas in isolated soy proteins, onset of gelation was above denaturation temperature of ${\beta}$-conglycinin with storage modulus increasing in two steps. The first increase in storage modulus of isolated soy proteins occurred at about $78.5^{\circ}C$, while the second increase started at about $93^{\circ}C$. Gel properties of soy protein gels having different proportions of glycinin and ${\beta}$-conglycinin were measured by compression-decompression test. ${\beta}$-conglycinin was responsible for gel elasticity. Glycinin significantly increased hardness, toughness, and fracturability of gels at high heating temperature near $100^{\circ}C$. Results reveal texture of soy protein gels can be controlled by regulating ratio of glycinin to ${\beta}$-conglycinin and heating temperature.

Debris Flows Mitigation by means of Flexible Barriers (토석류 피해저감을 위한 유연성 방호책 적용에 관한 연구)

  • You Byung-Ok;Chang Buhm-Soo;Choi Seung-Il;Choi Yu-Kyung
    • 기술발표회
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    • s.2006
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    • pp.220-231
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    • 2006
  • Debris flows are a natural hazard which looks like a combination of flood, land and rock slide. Large rainfall in July 2006 produced several large scale debris flows and many small debris flows that resulted in loss of life and considerable property and highway damage, as was widely reported in the national media. The hazard "debris flow" is still insufficiently researched Furthermore debris flows are very hard to predict. In this paper, a general over view of the debris flow problems along the highway, a generic way for the design and dimensioning of flexible barrier systems will be presented. A brief description of the various unique barrier types will be provided, too. The future for these barrier concepts looks promising because these barriers represent the state of art for such applications and are superior to many other available options.

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A Study on Decision of Voiced/Unvoiced Region through Measuring the Vocal Cord Property (성문특성 측정을 통한 유/무성음 결정에 관한 연구)

  • 민소연;강은영;신동성;배명진
    • Proceedings of the IEEK Conference
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    • 2001.06d
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    • pp.281-284
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    • 2001
  • Speech is classified into voiced signal and unvoiced signal. Since the amplitude of voiced fall off at about -20dB/decade, dynamic range is often compressed prior to spectral analysis so that details at weak, high frequencies may be visible[5][6] There is a distinct difference in spectrum slope between voiced signal and unvoiced signal. In this paper, we got the slope of each frame by using autocorrelation method, and determined voiced /unvoiced region. Also, we used energy to decide region of silence. To show experimental results, we allot to 1 value in voiced region, -1 value in unvoiced region and 0 value in silence region.

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The Effect of Surface Area of Silicas on Their Reinforcing Performance to Styrene-butadiene Rubber Compounds

  • Ryu, Changseok;Kim, Sun Jung;Kim, Do Il;Kaang, Shinyoung;Seo, Gon
    • Elastomers and Composites
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    • v.51 no.2
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    • pp.128-137
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    • 2016
  • The effect of the surface area of silicas on their reinforcing performance to styrene-butadiene rubber (SBR) compounds was systematically investigated. The feasibility of the Brunauer-Emmett-Teller surface area ($S_{BET}$) as a parameter representing the characteristics of the silicas was discussed compared to the mesopore volume, c value, oil absorption, and uptake of silane. The increase in $S_{BET}$ of silicas caused a considerable increase in Mooney viscosity, minimum torque, and hysteresis loss of the silica-filled SBR compounds, while significantly enhancing their abrasion property. These changes were explained by the attrition between the hydrophilic silica surface and the hydrophobic rubber chains. As expected, the change in $S_{BET}$ did not induce any remarkable changes in the cure, processing, tensile, and dynamic properties of the silica-filled SBR compounds because the crosslinking density of the rubber chains mainly determined these properties.

Seismic response Analysis of Building Structures considering the Nonlinear Property of Viscoelastic Dampers (점탄성 댐퍼의 비선형 특성을 고려한 건물의 지진응답해석)

  • Choi, Hyun;Kim, Doo-Hun;Min, Kyung-Won;Lee, Sang-Jo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.228-235
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    • 1999
  • As a seismic damper the viscoelastic damper is known the effective method to control the drift of the flexible building. As the viscoelastic damper has the characteristics of both damping and stiffness specially when the rubber material used hysteretic damping. The behavior of the hysteretic damping is quite different from that of the viscous damping. For the evaluation of the viscoelastic damper for the seismic purpose the nonlinear response spectrum was generated based on the dynamic test of the viscoelastic damper and the results is compared to that of the typical linear response spectrum,

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