The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Bo Xu - One of the best experts on this subject based on the ideXlab platform.

  • comparison of fwm and xpm induced crosstalk using the volterra series Transfer Function Method
    Journal of Lightwave Technology, 2003
    Co-Authors: Bo Xu, Maite Brandtpearce
    Abstract:

    New analytical tools to calculate the variance due to cross-phase modulation (XPM) and four-wave mixing (FWM) induced intensity distortion are derived based on the Volterra series Transfer Function Method. The analysis for both the XPM and FWM effects is based on the same system configuration with a continuous-wave (CW) probe channel plus modulated pump channels, which makes possible a fair comparison between the two nonlinear effects. Effective ways to reduce the XPM- and FWM-induced intensity distortion are given. The new results on the variance of the nonlinearity-induced intensity fluctuation also make it possible to study both synchronous wavelength-division multiplexing (WDM) systems with fixed channel delays and asynchronous WDM systems with random channel delays. The new analytical results provide accurate and efficient ways for system parameter optimization to reduce these two nonlinear effects.

  • Modified Volterra series Transfer Function Method
    IEEE Photonics Technology Letters, 2002
    Co-Authors: Bo Xu, Maite Brandt-pearce
    Abstract:

    In this letter, we offer a modified version of the Volterra series Transfer Function (VSTF) Method that has been previously proposed as an analytical solution to the nonlinear Schrodinger equation for single-mode fibers. The modified VSTF provides a simple closed-form expression of the output of a mildly nonlinear fiber. It gives orders more accurate result than the original VSTF Method and can successfully solve the energy divergence problem experienced by the original Method. The result is a stronger analytical tool for modeling signal propagation in optical communication systems.

  • Modified Volterra series Transfer Function Method and applications to fiber-optic communications
    Conference Record of Thirty-Fifth Asilomar Conference on Signals Systems and Computers (Cat.No.01CH37256), 2001
    Co-Authors: Bo Xu, Maite Brandt-pearce
    Abstract:

    We offer a modified version of the Volterra series Transfer Function (VSTF) Method that has been previously proposed as an analytical solution to the nonlinear Schrodinger (NLS) equation for single-mode fibers. The modified VSTF provides a simple closed-form expression of the output of a mildly nonlinear fiber. It gives orders more accurate result than the original VSTF Method and can successfully solve the energy divergence problem experienced by the original Method. The result is a stronger analytical tool for modeling signal propagation in optical communication systems.

Gerrit Vermeir - One of the best experts on this subject based on the ideXlab platform.

  • calibration of the two microphone Transfer Function Method with hard wall impedance measurements at different reference sections
    Mechanical Systems and Signal Processing, 2009
    Co-Authors: Rene Boonen, Wim Desmet, Walter Lauriks, Gerrit Vermeir
    Abstract:

    Abstract In many acoustic simulations, particularly when using lumped parameter models or electrical analog circuits, the acoustic impedance of a component needs to be determined accurately. A widely used acoustic impedance measurement Method is the “two microphone Transfer Function Method”, which is standardized in ISO-10534-2. When the acoustic impedance is needed over a wide frequency band with a high impedance magnitude range, this Method faces some limitations. In this paper, a calibration Method is proposed which uses hard wall impedance measurements at different positions of the reference section. The measured hard wall impedance is used to calibrate the microphone positions, to compensate the microphone mismatch and to estimate the wave guide damping. Also, the measured hard wall impedance can be used as performance criterion. It can be used to select frequency bands from different load impedance measurements where the accuracy is maximum and to assemble them in a load impedance measurement. As a result, impedances with a high ratio with respect to the characteristic duct impedance can be accurately measured. The capability of the presented calibration Method is illustrated by the impedance measurement of an open duct end and a closed tube.

  • Calibration of the two microphone Transfer Function Method by determining the hard wall impedance at shifted reference sections
    2008
    Co-Authors: Rene Boonen, Wim Desmet, Walter Lauriks, Gerrit Vermeir
    Abstract:

    In many acoustic simulations, particularly when using lumped parameter models or electrical analog circuits, the acoustic impedance of a component needs to be determined accurately. A widely used acoustic impedance measurement Method is the ”two microphone Transfer Function Method”, which is standardized in ISO-10534-2. When the acoustic impedance is needed over a wide frequency band with a high impedance magnitude range, this Method faces some limitations. In this paper, a calibration Method is proposed which uses hard wall impedance measurements at different positions of the reference section. The measured hard wall impedance is used to calibrate the microphone positions, to compensate the microphone mismatch and to estimate the wave guide damping. Also, the measured hard wall impedance can be used as performance criterion. It can be used to select frequency bands from different load impedance measurements where the accuracy is maximum and to assemble them in a load impedance measurement. As result, impedances with a high ratio with respect to the characteristic duct impedance can be accurately measured. The capability of the presented calibration Method is illustrated by the impedance measurement of an open duct end and a closed tube.

  • Calibration of the two microphone Transfer Function Method to measure acoustic impedance in a wide frequency range
    2006
    Co-Authors: Rene Boonen, Wim Desmet, Walter Lauriks, Gerrit Vermeir
    Abstract:

    In many acoustic simulations, particularly when using lumped parameter models or electrical analog circuits, the acoustic impedance of a component needs to be determined accurately. A widely used acoustic impedance measurement Method is the ”two microphone Transfer Function Method”, which is standardized in ISO-10534-2. When the acoustic impedance is needed over a wide frequency band, for example from 10Hz to 10kHz, this Method faces some limitations. In this paper, a new calibration Method will be proposed such that acoustic impedances can be measured with high accuracy over a wide frequency range. The estimation of the speed of sound has been eliminated. Using the measured Transfer Functions between the two sensors at two different reference sections, the sensor positions will be accurately calibrated. The calibration of the sensor mismatch has become superfluous, so interchanging positions of the sensors is not necessary. A recursive procedure has been proposed to maximize the microphone position accuracy. The resulting calibration procedure has been reduced to the accurate determination of the sensor positions.

Maite Brandt-pearce - One of the best experts on this subject based on the ideXlab platform.

  • Modified Volterra series Transfer Function Method
    IEEE Photonics Technology Letters, 2002
    Co-Authors: Bo Xu, Maite Brandt-pearce
    Abstract:

    In this letter, we offer a modified version of the Volterra series Transfer Function (VSTF) Method that has been previously proposed as an analytical solution to the nonlinear Schrodinger equation for single-mode fibers. The modified VSTF provides a simple closed-form expression of the output of a mildly nonlinear fiber. It gives orders more accurate result than the original VSTF Method and can successfully solve the energy divergence problem experienced by the original Method. The result is a stronger analytical tool for modeling signal propagation in optical communication systems.

  • Modified Volterra series Transfer Function Method and applications to fiber-optic communications
    Conference Record of Thirty-Fifth Asilomar Conference on Signals Systems and Computers (Cat.No.01CH37256), 2001
    Co-Authors: Bo Xu, Maite Brandt-pearce
    Abstract:

    We offer a modified version of the Volterra series Transfer Function (VSTF) Method that has been previously proposed as an analytical solution to the nonlinear Schrodinger (NLS) equation for single-mode fibers. The modified VSTF provides a simple closed-form expression of the output of a mildly nonlinear fiber. It gives orders more accurate result than the original VSTF Method and can successfully solve the energy divergence problem experienced by the original Method. The result is a stronger analytical tool for modeling signal propagation in optical communication systems.

Bingen Yang - One of the best experts on this subject based on the ideXlab platform.

  • SEMI-ANALYTICAL SOLUTION OF TWO-DIMENSIONAL ELASTICITY PROBLEMS BY FINITE DIFFERENCE–DISTRIBUTED Transfer Function Method
    International Journal of Structural Stability and Dynamics, 2010
    Co-Authors: Yaubin Yang, Bingen Yang
    Abstract:

    A semi-analytical solution Method, called the Finite Difference–Distributed Transfer Function Method, is developed for static and dynamic problems of two-dimensional elastic bodies composed of multiple rectangular subregions. In the development, the original two-dimensional elasticity problem is first reduced into a one-dimensional boundary-value problem by finite difference; the exact solution of the reduced problem is then obtained by using the distributed Transfer Functions of the elastic continuum. The proposed technique, which combines the simplicity of finite difference and the closed form of analytical solutions, is capable of handling arbitrary boundary conditions, delivers highly accurate solutions for static and dynamic problems, and is computationally efficient. The proposed Method is illustrated on a square region and an L-shaped region.

  • Modeling of Gossamer Space Structures with Distributed Transfer Function Method
    Journal of Spacecraft and Rockets, 2003
    Co-Authors: Houfei Fang, Bingen Yang, Yaubin Yang
    Abstract:

    A new structural modeling and analysis Method, the distributed Transfer Function Method, is presented for application to gossamer space structures. The distributed Transfer Function Method uses distributed Transfer Functions, instead of shape Function used by traditional finite element solvers, to represent the displacement field. The distributed Transfer Function Method maintains the modeling flexibility of the finite element Method, so that it is capable of modeling multibody complex structures, but it requires much fewer nodes and results in a significant reduction of computational time. The distributed Transfer Functions give rise to closed-form analytical solutions of both displacement and strain fields. As a result, the distributed Transfer Function Method only decomposes a structure at those points where multiple components are connected, to keep each component as large as possible. Gossamer space structures are generally composed of several long booms and large membranes. Therefore, the distributed Transfer Function Method can be used to model a gossamer structure with a small number of unknowns and matrices of low order. It offers very accurate results with high computational efficiency. The distributed Transfer Function Method is applied to investigate the sensitivity of buckling strength of an inflatable/rigidizable boom to the variations in bending stiffness.

  • Semi-analytical solution of 2-D elasticity problems by the strip distributed Transfer Function Method
    International Journal of Solids and Structures, 1996
    Co-Authors: Bingen Yang, J. Zhou
    Abstract:

    Abstract A new technique, called the strip distributed Transfer Function Method, is developed for static and dynamic analysis of two-dimensional elastic bodies that are composed of multiple rectangular subregions. The Method is capable of modeling elastic regions of complex geometry and arbitrary boundary conditions, delivers highly accurate semi-analytical solutions and saves tremendous computer storage. In the analysis, a complex elastic region is first divided into a number of subregions; each subregion is then divided into finite strips. Through introduction of strip distributed Transfer Functions, the response of every subregion is presented in a semi-exact and closed form; the whole region is systematically assembled from the subregions, leading to a dynamic equilibrium equation. Solution of the equilibrium equation yields the semi-exact displacements and stresses of the elastic body. The proposed Method is illustrated on a square region and an L-shaped region, and compared with the finite element Method.

  • Strip Distributed Transfer Function Method for Analysis of Plates
    International Journal for Numerical Methods in Engineering, 1996
    Co-Authors: J. Zhou, Bingen Yang
    Abstract:

    A semi-analytical Method, called the strip distributed Transfer Function Method, is developed for analysis of plate structures that are composed of rectangular plates. In the Method, a rectangular plate (substructure) is divided into a number of strips; the response of each strip is interpolated in the unknown nodal line displacements, which are Functions of the strip longitudinal co-ordinate and time. The nodal line displacements are determined in an exact and closed form by the distributed Transfer Functions that are defined along the strips. Synthesis of the substructures using the strip distributed Transfer Functions yields accurate prediction of the static and dynamic response, natural frequencies and buckling loads of the structure. The proposed Method is compared with some existing techniques in numerical examples.

  • Strip distributed Transfer Function Method for analysis of complex 2-D structures
    37th Structure Structural Dynamics and Materials Conference, 1996
    Co-Authors: Bingen Yang
    Abstract:

    An innovative semi-analytical solution technique, called the strip distributed Transfer Function Method, is developed for static and dynamic analysis of complex two-dimensional flexible structures. The Method is capable of modeling elastic continua of complex geometry and arbitrary boundary conditions, delivering highly accurate numerical, and saving tremendous computer storage. In the analysis, a complex elastic region is first divided into a number of subregions; each subregion is then divided into finite strips. Through introduction of strip distributed Transfer Functions, the response of every subregion is presented in a semi-exact and closed form; the whole region is systematically assembled from the subregions, leading to a dynamic equilibrium equation. Solution of the equilibrium equation yields the semi-exact displacements and stresses of the elastic body. The proposed Method is illustrated in numerical examples, and compared with the finite element Method and the finite strip Method.

Rene Boonen - One of the best experts on this subject based on the ideXlab platform.

  • calibration of the two microphone Transfer Function Method with hard wall impedance measurements at different reference sections
    Mechanical Systems and Signal Processing, 2009
    Co-Authors: Rene Boonen, Wim Desmet, Walter Lauriks, Gerrit Vermeir
    Abstract:

    Abstract In many acoustic simulations, particularly when using lumped parameter models or electrical analog circuits, the acoustic impedance of a component needs to be determined accurately. A widely used acoustic impedance measurement Method is the “two microphone Transfer Function Method”, which is standardized in ISO-10534-2. When the acoustic impedance is needed over a wide frequency band with a high impedance magnitude range, this Method faces some limitations. In this paper, a calibration Method is proposed which uses hard wall impedance measurements at different positions of the reference section. The measured hard wall impedance is used to calibrate the microphone positions, to compensate the microphone mismatch and to estimate the wave guide damping. Also, the measured hard wall impedance can be used as performance criterion. It can be used to select frequency bands from different load impedance measurements where the accuracy is maximum and to assemble them in a load impedance measurement. As a result, impedances with a high ratio with respect to the characteristic duct impedance can be accurately measured. The capability of the presented calibration Method is illustrated by the impedance measurement of an open duct end and a closed tube.

  • Calibration of the two microphone Transfer Function Method by determining the hard wall impedance at shifted reference sections
    2008
    Co-Authors: Rene Boonen, Wim Desmet, Walter Lauriks, Gerrit Vermeir
    Abstract:

    In many acoustic simulations, particularly when using lumped parameter models or electrical analog circuits, the acoustic impedance of a component needs to be determined accurately. A widely used acoustic impedance measurement Method is the ”two microphone Transfer Function Method”, which is standardized in ISO-10534-2. When the acoustic impedance is needed over a wide frequency band with a high impedance magnitude range, this Method faces some limitations. In this paper, a calibration Method is proposed which uses hard wall impedance measurements at different positions of the reference section. The measured hard wall impedance is used to calibrate the microphone positions, to compensate the microphone mismatch and to estimate the wave guide damping. Also, the measured hard wall impedance can be used as performance criterion. It can be used to select frequency bands from different load impedance measurements where the accuracy is maximum and to assemble them in a load impedance measurement. As result, impedances with a high ratio with respect to the characteristic duct impedance can be accurately measured. The capability of the presented calibration Method is illustrated by the impedance measurement of an open duct end and a closed tube.

  • Calibration of the two microphone Transfer Function Method to measure acoustic impedance in a wide frequency range
    2006
    Co-Authors: Rene Boonen, Wim Desmet, Walter Lauriks, Gerrit Vermeir
    Abstract:

    In many acoustic simulations, particularly when using lumped parameter models or electrical analog circuits, the acoustic impedance of a component needs to be determined accurately. A widely used acoustic impedance measurement Method is the ”two microphone Transfer Function Method”, which is standardized in ISO-10534-2. When the acoustic impedance is needed over a wide frequency band, for example from 10Hz to 10kHz, this Method faces some limitations. In this paper, a new calibration Method will be proposed such that acoustic impedances can be measured with high accuracy over a wide frequency range. The estimation of the speed of sound has been eliminated. Using the measured Transfer Functions between the two sensors at two different reference sections, the sensor positions will be accurately calibrated. The calibration of the sensor mismatch has become superfluous, so interchanging positions of the sensors is not necessary. A recursive procedure has been proposed to maximize the microphone position accuracy. The resulting calibration procedure has been reduced to the accurate determination of the sensor positions.