• Title/Summary/Keyword: inhomogeneous

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Evolution of bone structure under axial and transverse loads

  • Qu, Chuanyong;Qin, Qing-Hua
    • Structural Engineering and Mechanics
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    • v.24 no.1
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    • pp.19-29
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    • 2006
  • The evolution process of an initially homogeneous bone structure under axial and transverse loads is investigated in this paper. The external loads include axial and external lateral pressure, electric, magnetic and thermal loads. The theoretical predictions of evolution processes are made based on the adaptive elasticity formulation and coupled thermo-magneto-electro-elastic theory. The adaptive elastic body, which is a model for living bone diaphysis, is assumed to be homogeneous in its anisotropic properties and its density. The principal result of this paper is determination of the evolution process of the initially homogeneous body to a transversely inhomogeneous body under the influence of the inhomogeneous stress state.

Electromagnetic Interference Analysis of an Inhomogeneous Electromagnetic Bandgap Power Bus for High-Speed Circuits

  • Cho, Jonghyun;Kim, Myunghoi
    • Journal of information and communication convergence engineering
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    • v.15 no.4
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    • pp.237-243
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    • 2017
  • This paper presents an analysis of the electromagnetic interference of a heterogeneous power bus where electromagnetic bandgap (EBG) cells are irregularly arranged. To mitigate electrical-noise coupling between high-speed circuits, the EBG structure is placed between parallel plate waveguide (PPW)-based power buses on which the noise source and victim circuits are mounted. We examine a noise suppression characteristic of the heterogeneous power bus in terms of scattering parameters. The characteristics of the dispersion and scattering parameters are compared in the sensitivity analysis of the EBG structure. Electric field distributions at significant frequencies are thoroughly examined using electromagnetic simulation based on a finite element method (FEM). The noise suppression characteristics of the heterogeneous power bus are demonstrated experimentally. The heterogeneous power bus achieves significant reduction of electrical-noise coupling compared to the homogeneous power buses that are adopted in conventional high-speed circuit design. In addition, the measurements show good agreement with the FEM simulation results.

Estimation of Discontinuity Orientations in Excavation Faces (굴착면에서의 분리면방향성 평가)

  • Ro, Byung-Don;Han, Byeong-Hyeon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1484-1489
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    • 2005
  • An inhomogeneous and anisotropic rock has different properties at different location. Thus, this refers to any of the properties which we may be measuring. There are two concepts of rock mass, namely, CHILE(Continuous, Homogeneous, Isotropic, Linear Elastic) material and DIANE(Discontinuous, Inhomogeneous, Anisotropic, Non-linear Elastic) rock. The former is essentially the properties of intact rock, the latter is essentially the properties governed by the structure of rock. In geotechnical aspect, the most important parameter is strength of rock or rock mass. In particular, characteristics of strength of rock mass depend upon the orientation of discontinuities And this orientation of discontinuities has different properties at different direction of excavation. Therefore, it needs for characterization of different properties of discontinuity orientation against different direction of excavation.

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Network Optimization in the Inhomogeneous Distribution Using Genetic Algorithm Traffic (유전자 알고리즘을 이용한 비균일 트래픽 환경에서의 셀 최적화 알고리즘)

  • 박병성;한진규;최용석;조민경;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.2B
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    • pp.137-144
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    • 2002
  • In this paper, we optimize the base station placement and transmission power using genetic approach. A new representation describing base station placement and transmit power with real number is proposed, and new genetic operators are introduced. This new representation can describe the locations, powers, and number of base stations, Considering coverage, power and economy efficiency, we also suggest a weighted objective function. Our algorithm is applied to an obvious optimization problem, and then it is verified. Moreover, our approach is tried in inhomogeneous traffic distribution. Simulation result proves that the algorithm enables to fad near optimal solution according to the weighted objective function.

Effects of Asymmetric Distribution of Charged Defects on the Hysteresis Curves of Ferroelectric Capacitors

  • Lee Kang-Woon;Kim Yong-Il;Lee Won-Jong
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.3 s.36
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    • pp.219-226
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    • 2005
  • When a ferroelectric film has an inhomogeneous distribution of charged defects, a voltage shift in the polarization curve is induced by the internal field generated in the film. The direction and the magnitude of voltage shift in the P-V hysteresis curves obtained by the Sawyer-Tower method are different from those obtained by the virtual ground method. In this study, the asymmetric behavior in the P-V hysteresis curves of inhomogeneous ferroelectric films was investigated with a physical model and the polarization curves obtained by the Sawyer-Tower and the virtual ground methods are compared.

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Iterative Inversion Using Moment Method and Improved Newton`s AIgorithmin the Configuration Domain (공간영역에서 모멘트방법과 개선된 Newton 알고리즘을 이용한 반복 역산란 방법)

  • 박천석;김정혜;라정웅
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.5
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    • pp.39-49
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    • 1994
  • In this paper, An inversion technique to reconstruct permittivity profiles of 2-D inhomogeneous dielectric objects by iterativeprocess using the moment-methodand improved newton's algoritham is presented. In order to reduce the noise effect in the scattered fieldon the reconstructed permittivity profiles, the cell size of inversescattering is made be larger than that of forward scattering. Performing numerical calculations of dielectric scatterer it is demonstrated that this inversion is able to reconstruct dielectric objectshaving large size and inhomogeneous characteristics, which is insentive tothe noise effect in the scattered field on the reconstructed result.

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CIRCUMSTELLAR PECULIARITIES IN INHOMOGENEOUS ENVELOPES OF THE YOUNG HERBIG AE/BE STARS

  • POGODIN MIKHAIL
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.259-259
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    • 1996
  • Circumstellar peculiarities of the young Herbig Ae/Be stars are analyzed using high-resolution CCD spectroscopic data, obtained in 1991-1996 at the ESO and the Crimean Astrophysical Observatory (about 450 spectrograms). The results of investigation of the rapid line variability in H$\alpha$, H$\beta$, HeI 5876 and DNaI lines are presented for AB Am, HD 163296, HD 36112, HD 100546, and HD 50138. We conclude that the behaviour of these lines can be explained in the framework of the model containing an equatorially concentrated and azimuthally inhomogeneous stellar wind, and an external cool shell that occasionally looses matter in form of infall onto the star.

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OPTIMAL CONTROL OF THE HEAT EQUATION IN AN INHOMOGENEOUS BODY

  • Borzabadi, A.H.;Kamyad, A.V.;farahi, M.H.
    • Journal of applied mathematics & informatics
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    • v.15 no.1_2
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    • pp.127-146
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    • 2004
  • In this paper we consider a heat flow in an inhomogeneous. body without internal source. There exists special initial and boundary conditions in this system and we intend to find a convenient coefficient of heat conduction for this body so that body cool off as much as possible after definite time. We consider this problem in a general form as an optimal control problem which coefficient of heat conduction is optimal function. Then we replace this problem by another in which we seek to minimize a linear form over a subset of the product of two measures space defined by linear equalities. Then we construct an approximately optimal control.

Crack Propagation at Boundary Face of Composite Compact Tension Specimen

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.337-341
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    • 2013
  • In this study, fatigue crack propagation in composite material under fatigue is investigated by simulation result. When another material on the specimen exists vertically to the crack line, the phenomena that crack may go straight or propagate along the boundary face according to the elastic modulus ratio of another material to matrix are investigated with compact tension specimen by compliance method. Crack propagation direction is evaluated by compliance method. By arranging this study result systematically about the crack propagation behavior due to the stiffness of inhomogeneous material, high-tech material (automobile, aircraft and steel industry) can be improved. The estimation of safety design and life (construction & nuclear power station, etc.) will be of great value industrially.

Charges of TIP4P water model for mixed quantum/classical calculations of OH stretching frequency in liquid water

  • Jeon, Kiyoung;Yang, Mino
    • Rapid Communication in Photoscience
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    • v.5 no.1
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    • pp.8-10
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    • 2016
  • The potential curves of OH bonds of liquid water are inhomogeneous because of a variety of interactions with other molecules and this leads to a wide distribution of vibrational frequency which hampers our understanding of the structure and dynamics of water molecules. Mixed quantum/classical (QM/CM) calculation methods are powerful theoretical techniques to help us analyze experimental data of various vibrational spectroscopies to study such inhomogeneous systems. In a type of those approaches, the interaction energy between OH bonds and other molecules is approximately represented by the interaction between the charges located at the appropriate interaction sites of water molecules. For this purpose, we re-calculated the values of charges by comparing the approximate interaction energies with quantum chemical interaction energies. We determined a set of charges at the TIP4P charge sites which better represents the quantum mechanical potential curve of OH bonds of liquid water.