• Title/Summary/Keyword: Equivalent k

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Simple method for static and dynamic analyses of guyed towers

  • Meshmesha, H.;Sennah, K.;Kennedy, J.B.
    • Structural Engineering and Mechanics
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    • v.23 no.6
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    • pp.635-649
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    • 2006
  • The static and dynamic responses of guyed telecommunication towers can be determined by using two models, the space truss element model, and the equivalent beam-column element model. The equivalent beam-column analysis is based on the determination of the equivalent shear, torsion, and bending rigidities as well as the equivalent area of the guyed mast. In the literature, two methods are currently available to determine the equivalent properties of lattice structures, namely: the unit load method, and the energy approach. In this study, an equivalent beam-column analysis is introduced based on an equivalent thin plate approach for lattice structures. A finite-element modeling, using suitably modified ABAQUS software, is used to investigate the accuracy of utilizing the different proposed methods in determining the static and dynamic responses of a guyed tower of 364.5-meter high subjected to static and seismic loading conditions. The results from these analyses are compared to those obtained from a finite-element modeling of the actual structure using 3-D truss and beam elements. Good agreement is shown between the different proposed beam-column models, and the model of the actual structure. However, the proposed equivalent thin plate approach is simpler to apply than the other two approaches.

New Force Expression on Dielectrics: Equivalent Electrifying Current Method

  • Choi, Hong-Soon;Lee, Se-Hee
    • Journal of Electrical Engineering and Technology
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    • v.12 no.6
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    • pp.2262-2267
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    • 2017
  • A new force expression on dielectrics subjected to electric field is proposed in this paper. It is the electric version of the equivalent magnetizing current method in magnetic field. From the idea of electromagnetic duality, virtual equivalent electrifying magnetic current method is conjectured in the field of dielectric force problem. Numerical results show that the proposed method has good agreements with the conventional methods. The merits and demerits of the proposed method are also discussed.

TRV analysis by using multi - port equivalent (다 단자망 축약 이론을 이용한 TRV 해석)

  • Yoon, Jae-Young;Moon, Young-Hyun;Park, Dong-Wook
    • Proceedings of the KIEE Conference
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    • 1988.11a
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    • pp.236-240
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    • 1988
  • The simplified equivalent by using the short circuit impedance has been used for analyzing the prospective transient recovery voltage of the large power system. But it sometimes generates untorelable error in the rate-of-rise of TRV when using the Thevenin equivalent source. This paper provides the new equivalent by using the multi-port theory. The application of the new method to the sample system gives satisfactory accuracy compared with the short-circuit equivalent.

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Development of Dermal Equivalent Using Mouse Fibroblasts (세포조직배양법을 이용한 쥐 인공피부의 개발)

  • Yang, Eun-Kyoung;Lee, Jae-Ho;Choe, Tae-Boo;Park, Jung-Keug
    • Microbiology and Biotechnology Letters
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    • v.21 no.4
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    • pp.381-391
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    • 1993
  • As the first stage of development of an artificial skin, fibroblasts were cultured in the collagen matrices to make a living dermal equivalent. Mouse embryonic fibroblasts were incorporated into a collagen matrices on plastic dishes containing concentrated DMEM culture media supplemented with sodium bicarbonate, hepes, antibiotics and fetal bovine serum. As the growth stimulation components, glycosaminoglycans were added: hyaluronic acid, chondroitin sulfate, heparin, chitosan were incorporated into the media at a concentration of either 1% or 5% w/w/ to collagen in order to investigate the effect on development of dermal equivalent. After the few days of incubation, gel matrics were contracted and firm dermal equivalent were formed. And the keratinocytes were cultured on top of dermal equivalent and make a three dimensional artificial skin tissue.

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Calculation of the Parameter according to the Slip in Squirrel-Cage Induction Motor (Slip에 따른 농형유도전동기의 회로정수 산정)

  • Lee, Su-Jin;Lee, Jeong-Jong;Kim, Sung-Il;Hong, Jung-Pyo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.738_739
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    • 2009
  • This paper describes the calculation of the equivalent circuit parameters according to the slip in squirrel-cage induction motor. Recently, the induction motor is demanded of the various operation condition. In order to acquire the accurate characteristic for the operation condition of the motor, equivalent circuit parameters have to be calculated accurately. So the equivalent circuit parameters are computed by using the finite element method, the reliable characteristic analysis is carried out by application of the parameter to the equivalent circuit analysis. From the analysis result using this combined equivalent circuit and finite element method is compared with the experimental results by a detailed equivalent circuit, the validity of the method is proved.

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A Phase-Domain Equivalent Representation for Electromagnetic Transients Studies (전력계통 과도현상 해석을 위한 상영역에서의 등가축약 기법)

  • Jung, B.T.;Kim, S.H.;Heo, S.I.;Ahn, B.S.;Hong, J.H.
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.731-733
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    • 1996
  • In this paper, a new time-domain reduction method for unbalanced 3 phase power systems will be represented. The impulse response of the system is used to identify a discrete-time equivalent filter model. The model is formulated directly in the phase domain. Each phase has a self-mode equivalent model and two mutual-mode equivalent models. The equivalent model is determined by the transfer function identification technique based on the Prony analysis. The model is implemented in EMTDC and tested with an unbalanced 3 phase network. The result of test showed that the equivalent model is accurate.

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ON LOCALLY B*- EQUIV ALENT ALGEBRAS

  • Kang, Soon-Ja
    • Honam Mathematical Journal
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    • v.4 no.1
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    • pp.167-172
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    • 1982
  • Let A be a Banach $^{\ast}$-algebra and C(t) be a closed $^{\ast}$-subalgebra of A gengerated by $t{\in}A$. A is locally $B^{\ast}$-equivalent [$B^{\ast}$-equivalent] if C(t) [A] for every hermitian element t is $^{\ast}$-isomorphic to some $B^{\ast}$-algebra. It was proved that the locally $B^{\ast}$-equivalent algebras with some conditions is $B^{\ast}$-equivalent by B. A. Barnes. In this paper, we obtain the some conditions for a locally $B^{\ast}$-equivalent algebra to be $B^{\ast}$-equivalent.

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Determination of Equivalent Roughness for Estimating Flow Resistance in Stabled Gravel-Bed River: II. Review of Model Applicability

  • Park, Sang-Woo;Lee, Sin-Jae;Jang, Suk-Hwan
    • Journal of Environmental Science International
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    • v.17 no.11
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    • pp.1211-1220
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    • 2008
  • In this study, we estimated, the equivalent roughness using an estimation model, which considered grain distribution on the bed and the protrusion height of the grains. We also reviewed the appropriateness of the estimated equivalent roughness at the Goksung and Gurey station in the Seomjin River. To review the appropriateness of this model, we presented the water level-discharge relation curve applying the equivalent roughness to the flow model and compared and reviewed it to observed data. Also, we compared and reviewed the observed data by estimating the Manning coefficient n, the Chezy coefficient C, and the Darcy-Weisbach friction coefficient f by the equivalent roughness. The calculation results of the RMSE showed within 5% error range in comparison with observed value. Therefore the estimated equivalent roughness values by the model could be proved appropriate.

A Boundary Protection for Power Distribution Line Based on Equivalent Boundary Effect

  • Zhang, Xin;Mu, Long-Hua
    • Journal of Electrical Engineering and Technology
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    • v.8 no.2
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    • pp.262-270
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    • 2013
  • A boundary protection method for power distribution line based on equivalent boundary effect is presented in this paper. In the proposed scheme, the equivalent resonance component with a certain central frequency is sleeve-mounted at the beginning of protected zone. The 'Line Boundary' is built by using boundary effect, which is created by introducing impedance in the primary-side of line. The 'Line Boundary' is significantly different from line wave impedance. Therefore, the boundary protection principle can be applied to power distribution line without line traps. To analyze the frequency characteristic corresponding to traveling-waves of introducing impedance in the primary-side of line, distributed parameters model of equivalent resonance component is established. The results of PSCAD/EMTDC simulation prove the obvious difference of voltage high frequency component between internal faults and external faults due to equivalent resonance component, and validate the scheme.