• Title/Summary/Keyword: approximation technique

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Second Harmonic Generation study on the transport dynamics of small molecules across liposome bilayers

  • Kim, Joon-Heon;Kim, Mahn-Won
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.79-79
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    • 2003
  • SHG (Second harmonic generation) can be used to probe the surface of centrosymmetric particles suspended in bulk isotropic solution, because it is forbidden in centrosymmetric media under the dipole approximation. Using this technique, we can study the transport dynamics of small organic dye molecules across liposome bilayers. Because molecules adsorbed on the outer layer are in opposite direction with that on the inner layer by symmetry, the SH field is proportional to the difference between the number density of dye molecules on both sides of the bilayer, and the time dependence of the SH intensity is related to the time constant of the molecular transportation of dye molecules across liposome bilayers.

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An Analytical Modeling of Threshold Voltage and Subthreshold Swing on Dual Material Surrounding Gate Nanoscale MOSFETs for High Speed Wireless Communication

  • Balamurugan, N.B.;Sankaranarayanan, K.;Amutha, P.;John, M. Fathima
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.3
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    • pp.221-226
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    • 2008
  • A new two dimensional (2-D) analytical model for the Threshold Voltage on dual material surrounding gate (DMSG) MOSFETs is presented in this paper. The parabolic approximation technique is used to solve the 2-D Poisson equation with suitable boundary conditions. The simple and accurate analytical expression for the threshold voltage and sub-threshold swing is derived. It is seen that short channel effects (SCEs) in this structure is suppressed because of the perceivable step in the surface potential which screens the drain potential. We demonstrate that the proposed model exhibits significantly reduced SCEs, thus make it a more reliable device configuration for high speed wireless communication than the conventional single material surrounding gate (SMSG) MOSFETs.

A Study on the Pitch Alteration Technique by Subband Scaling in Speech Signal (서브밴드 스케일링에 의한 음성신호의 피치변경법에 관한 연구)

  • Kim, Young-Kyu;Bae, Myung-Jin
    • Speech Sciences
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    • v.10 no.4
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    • pp.137-147
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    • 2003
  • Speech synthesis can classify by synthesis way, that is waveform coding, source coding and mixture coding. Specially, waveform coding is suitable for high quality synthesis. However, it is not desirable by synthesis techniques of syllable or phoneme unit because it do not separate and handles excitation and formant part. Therefore, there is a need for pitch alteration method applied in synthesis by the rule in waveform coding. This study propose about pitch alteration method that use spectrum scaling after do to flatten spectra by subband linear approximation to minimize spectrum distortion. This paper show evaluation whether show excellency of some measure compared with LPC, Cepstrum, lifter function and method that propose. estimation method seeks distribution of each flattened signal and measured degree of flattened spectra Signal flattened is normalized, So that highest point amounts to zero, and distribution of signal ,whose average is zero, is calculated. this show result that measure the spectrum distortion rate to estimate performance of method that propose. The average spectrum distortion rate was kept below the average 2.12%, so the method that propose is superiors than existent method.

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A Study on the Structural-acoustic Analysis Modeling Methods of the Room with Heavy Impact Noise Source (중량충격원 충격에 따른 공동주택 실내공간의 구조음장 해석 모델링방법에 관한 연구)

  • Lee, Jae-Kwang;Koo, Hae-Shik
    • KIEAE Journal
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    • v.9 no.6
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    • pp.81-87
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    • 2009
  • The purpose of the present study is to establish structural noise analyzing method for apartments building floor with structural-acoustic coupling analysis modeling. Noise through floor in the room is recognized as a significant problem with the consequence that noise isolation technique has been studied in the various fields of industry. From among noise factors, resonance sound is the main reason for solid noise of the floor, which is occurred by mechanical vibrations of the acoustic boundary line and the change of velocity. To analyse this phenomenon, numerical computation methods are provided in many fields, In this study, evaluation method for slab is established using finite element method, and a case study for analyzing acoustic phenomenon was suggested. The results show that numerical method, especially F.E.M, has a good approximation to predict noise at floors.

A Measurement-Based Adaptive Control Mechanism for Pricing in Telecommunication Networks

  • Davoli, Franco;Marchese, Mario;Mongelli, Maurizio
    • Journal of Communications and Networks
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    • v.12 no.3
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    • pp.253-265
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    • 2010
  • The problem of pricing for a telecommunication network is investigated with respect to the users' sensitivity to the pricing structure. A functional optimization problem is formulated, in order to compute price reallocations as functions of data collected in real time during the network evolution. No a-priori knowledge about the users' utility functions and the traffic demands is required, since adaptive reactions to the network conditions are sought in real time. To this aim, a neural approximation technique is studied to exploit an optimal pricing control law, able to counteract traffic changes with a small on-line computational effort. Owing to the generality of the mathematical framework under investigation, our control methodology can be generalized for other decision variables and cost functionals.

Time-dependent analysis of launched bridges

  • Mapelli, M.;Mola, F.;Pisani, M.A.
    • Structural Engineering and Mechanics
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    • v.24 no.6
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    • pp.741-764
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    • 2006
  • The time-dependent analysis of prestressed concrete bridges built adopting the incremental launching technique is presented. After summarizing the well known results derived from the elastic analysis, the problem is approached in the visco-elastic domain taking into account the effects consequent to the complex load history affecting the structure. In particular, the effects produced by prestressing applied both in the launching phase and after it and by application of imposed displacements and of delayed restraints during the launching phases are carefully investigated through a refined analytical procedure. The reliability of the proposed algorithm is tested by means of comparisons with reference cases for which exact solutions are known. A case study of general interest is then discussed in detail. This case study demonstrates that a purely elastic approach represents a too crude approximation, which is unable to describe the specific character of the problem.

Soil interaction effects on sloshing response of the elevated tanks

  • Livaoglu, Ramazan
    • Geomechanics and Engineering
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    • v.5 no.4
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    • pp.283-297
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    • 2013
  • The aim of this paper is to investigate how the soil-structure interaction affects sloshing response of the elevated tanks. For this purpose, the elevated tanks with two different types of supporting systems which are built on six different soil profiles are analyzed for both embedded and surface foundation cases. Thus, considering these six different profiles described in well-known earthquake codes as supporting medium, a series of transient analysis have been performed to assess the effect of both fluid sloshing and soil-structure interaction (SSI). Fluid-Elevated Tank-Soil/Foundation systems are modeled with the finite element (FE) technique. In these models fluid-structure interaction is taken into account by implementing Lagrangian fluid FE approximation into the general purpose structural analysis computer code ANSYS. A 3-D FE model with viscous boundary is used in the analyses of elevated tanks-soil/foundation interaction. Formed models are analyzed for embedment and no embedment cases. Finally results from analyses showed that the soil-structure interaction and the structural properties of supporting system for the elevated tanks affected the sloshing response of the fluid inside the vessel.

Analysis of Torque on Spur Gear by Inverse Problem (역문제에 의한 평치차의 토크 해석)

  • 박성완;이장규;우창기;김봉각;윤종희;인승현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.3-10
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    • 2002
  • This study proposed a technique for inverse problem, linear approximation of contact position and loading in single and double meshing of spur gear, using 2-dimension model considered near the tooth by root stress. Determine root stress is carried out for the gear tooth by finite element method and boundary element method. Boundary element discretization near contact point is carefully performed to keep high computational accuracy. And from those estimated results, the comparing estimate value with boundary element method value was discussed.

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Analysis of Spiral Bevel Gear by Inverse Problem (역문제에 의한 스파이얼 베벨기어의 해석)

  • 박성완
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.5
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    • pp.85-95
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    • 2001
  • This study proposed a technique for inverse problem, linear approximation of contact position and loading in single and double meshing of spiral bevel gear , using 2-dimension model considered near the tooth by root stress. Determine root stress is carried out far the gear tooth by finite element method and boundary element method. Boundary element discretization near contact point is carefully performed to keep high computational accuracy. And from those estimated results, the comparing estimate value with boundary element method value was discussed.

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Analysis of Torque on Spur Gear by Inverse Problem (역문제에 의한 평치차의 토크 해석)

  • 박성완
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.5
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    • pp.24-33
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    • 2003
  • This study proposed a technique for inverse problem, linear approximation of contact position and loading in single and double meshing of transmission contact element using 2-dimension model considered near the tooth by root stress. Determination of root stress is carried out far the gear tooth by finite element method and boundary element method. Boundary element discretization near contact point is carefully performed to keep high computational accuracy. The predicted results of boundary element method are good accordance with that of finite element method.