• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.252-257
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• 2006

Low vibration characteristics of a vehicle are mainly influenced by the local stiffness of the joint structure beam section. The method of substituting equivalent beam element to spring element for the joint is presented. Formation process of the equivalent beam joint modeling is described in terms of key section properties. To get required dynamic characteristics section properties of the equivalent beam element are set to design variables. The study shows that the equivalent beam joint model can be effectively used for low frequency vibration analysis of a vehicle.

• School Mathematics
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• v.4 no.3
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• pp.463-481
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• 2002

In this paper, I review the historical background of "the principle of the permanence of equivalent forms" and sum- marize properties of "the principle of the permanence of equivalent forms" as a kind of heuristic. 1 think that "the principle of the permanence of equivalent forms" can be used effectively for student's discovery of the algebraic structure. There are three ways of using "the principle of the permanence of equivalent forms" in extending number system - an extension on the base of set theory(SMSC), the formal or axiomatic extrapolation and the inductive-extrapolatory method. All those three methods are mixed up and being used potentially at various levels in current Korean text books. "The principle of the permanence of equivalent forms" is used most effectively in the subject of the exponent. 1 try to present a situation that makes the students find more general definition and cultivate their desirable attitudes for the mathematics in the process of extending the exponent through summarizing the debate between Goel & Robillard(1997) and Tirosh S, Even(1997).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2041-2046
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• 2008

A frequency-dependent slow-wave factor (SWF) and equivalent circuit model of transmission line with defected ground structures (DGS) is described. Once S-parameters of a DGS transmission line are given, the conventional frequency -independent equivalent circuit elements are extracted using 3dB cutoff and resonant frequencies (Fc and Fo) as the first step. Using the initial equivalent elements and simple transmission line theories, a frequency-dependent equivalent transmission line model is established through an analytical method, and finally the frequency dependent SWF is calculated. The proposed equivalent circuit model and SWF are frequency-dependent and more reliable because even small insertion loss within available passband is considered, while they have been independent of frequency.

• 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.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1012-1016
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• 2004

In the present paper, equivalent beam and equivalent bimorph beam models for IPMC(ionic Polymer-Metal Composite) actuators are described. Physical properties of an IPMC, such as Young's modulus and electro-mechanical coupling coefficient. are determined from the rule of mixture, bimorph beam equations, and measured force-displacement data of a cantilevered IPMC actuator. By using a beam equation with estimated physical properties, actuation displacements of a cantilevered IPMC actuator was calculated and a good agreement between the computed tip displacements and the measured data was observed. Finite element analysis(FEA) combined with the estimated physical properties was used to reproduce the force-displacement relationship of an IPMC actuator. Results from the FEA agreed well with the measure data. The proposed models might be used for modeling of IPMC actuators with complicated shapes and boundary conditions.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1834-1846
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• 2020

The SMART (System-integrated Modular Advanced ReacTor) is an integral-type small modular reactor developed by KAERI (Korea Atomic Energy Research Institute). This paper discusses the development of a dynamic equivalent model of the SMART control rod drive mechanism that can be efficiently utilized for complicated analysis during the design of the SMART. A semi-empirical approach is used to develop the equivalent model; that is, the equivalent model is defined analytically and verified empirically. Two types of tests, dynamic characteristics tests and seismic loading tests, are conducted for the development and verification of the dynamic equivalent model, respectively. Acceleration response spectra from the seismic analysis based on the developed equivalent model show good agreement with those from the seismic loading tests.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.18-23
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• 2012

A method to determine the equivalent circuits of broadband ultrasound transducers is necessary for designing filters that match the impedances of the transducer and the analysis of the transducer. A method is proposed to determine the equivalent circuits of broadband transducers with 2 resonances in the frequency band of interest. The circuit parameters are estimated by iterative Levy method with the measured electrical conductance data. The method is illustrated by computing the conductance and susceptance of the equivalent circuits of 3 types of broadband transducers. The equivalent circuit of a transducer.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.19-26
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• 2003

In energy-based design, the structures are generally transformed into equivalent SDOF systems to obtain the input and the dissipated energy. In this study the energy demands in multi-story structures were compared with that of equivalent single degree of freedom systems to validate the transformation method. Three-, eight-, and twenty-story steel moment-resisting frames and buckling restrained braced frames are compared with those of equivalent single degree of freedom systems. Sixty earthquake ground motions recorded in different soil conditions were used to compute the input and hysteretic energy demands in model structures. According to the analysis results, in 3 and 8-story structures the hysteretic energy demands computed in the equivalent SDOF structures are compatible with those computed in the original MDOF structures, while in the 20-story structures the transformed equivalent structures underestimated the hysteretic energy demands.

• KCI Concrete Journal
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• v.13 no.1
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• pp.11-17
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• 2001

The purpose of this state-of-the-art paper is to explore several important methods thor obtaining the equivalent loads in prestressed concrete structures. and to clarify the theoretical basis and implied assumptions of each method. The method devised in this stuffily include the use of curvature of tendon, characteristics of primary moment, self-equilibrium condition and linear segments approximation of tendon. It is shown that equivalent loading system it not uniquely determined depending on the approach adopted to calculate the equivalent loads. Self-equilibrium conditions of the equivalent loading system are carefully discussed. Numerical examples are presented to show the differences among the methods arid results of the approximations in each method explicitly.