The Experts below are selected from a list of 141585 Experts worldwide ranked by ideXlab platform

Kwangil Seon - One of the best experts on this subject based on the ideXlab platform.

  • smoothing of an all sky survey map with a fisher von mises Function
    arXiv: Astrophysics, 2007
    Co-Authors: Kwangil Seon
    Abstract:

    A convolution of the all-sky survey data with a smoothing Function is crucial in calculating the smooth surface brightness of the sky survey data. The convolution is usually performed using a spherical version of the convolution theorem. However, a Gaussian Function, applicable only in the flat-sky approximation, has been usually adopted as a smoothing kernel. In this paper, we present an exact analytic solution of the spherical-harmonics transformation of a Fisher-von Mises Function, the mathematical version of a Gaussian Function in spherical space. We also obtain the approximate solutions exp[-l(l + 1)/2k]. The exact and the approximate solutions may be useful when an astrophysical survey map is convolved with a smoothing Function of k>1.

  • smoothing of an all sky survey map with a fisher von mises Function
    Journal of the Korean Physical Society, 2006
    Co-Authors: Kwangil Seon
    Abstract:

    Convolution of all-sky survey data with a smoothing Function is crucial in calculating the smooth surface brightness of the sky survey data. The convolution is usually performed using the spherical version of the convolution theorem. However, a Gaussian Function, applicable only in flat-sky approximation, has been usually adopted as a smoothing kernel. In this paper, we present an exact analytic solution of the spherical harmonic transformation of a Fisher-von Mises Function, the mathematically version of a Gaussian Function in spherical space. We also obtain the approximate solutions exp[−l(l + 1)/2κ]. The exact and approximate solutions may be useful when an astrophysical survey map is convolved with a smoothing Function of κ > 1.

Serdar Ozoguz - One of the best experts on this subject based on the ideXlab platform.

  • TSP - CMOS implementation of scalable Morlet wavelet for application in signal processing
    2015 38th International Conference on Telecommunications and Signal Processing (TSP), 2015
    Co-Authors: Ali Naderi Saatlo, Serdar Ozoguz
    Abstract:

    Implementation of Morlet wavelet using current-mode circuits is presented in CMOS technology. The circuit consists of four main building blocks: squaring circuit, exponential Function generator circuit, Gaussian Function generator circuit and analog multiplier circuit. The proposed structure is fully programmable in terms of standard deviation and peak gain of the Gaussian Function. Therefore Morlet wavelet can be programmed to define different scaling and shifting parameters. Simulation results of the circuits are obtained by HSPICE in 0.35μm standard CMOS process. Simulated results verify the feasibility of both the wavelet realization and proposed circuits.

  • on the realization of Gaussian membership Function circuit operating in saturation region
    International Conference on Telecommunications, 2015
    Co-Authors: Ali Naderi Saatlo, Serdar Ozoguz
    Abstract:

    In this paper a novel method for realization of Gaussian Function is presented. The current-mode circuits are employed for the implementation of main circuits owing to the simple circuitry and intuitive configuration. Unlike the previous works which were based on the transistors worked in weak inversion region, the proposed configuration operates in the saturation region, therefore high-accuracy as well as the highspeed performance are obtained. The proposed circuit is fully programmable in terms of mean value, standard deviation and peak gain of the Gaussian Function. Simulation results of the circuit is obtained by HSPICE with TSMC level 49 (BSIM3v3) parametes in 0.35μm standard CMOS process.

  • TSP - On the realization of Gaussian membership Function circuit operating in saturation region
    2015 38th International Conference on Telecommunications and Signal Processing (TSP), 2015
    Co-Authors: Ali Naderi Saatlo, Serdar Ozoguz
    Abstract:

    In this paper a novel method for realization of Gaussian Function is presented. The current-mode circuits are employed for the implementation of main circuits owing to the simple circuitry and intuitive configuration. Unlike the previous works which were based on the transistors worked in weak inversion region, the proposed configuration operates in the saturation region, therefore high-accuracy as well as the highspeed performance are obtained. The proposed circuit is fully programmable in terms of mean value, standard deviation and peak gain of the Gaussian Function. Simulation results of the circuit is obtained by HSPICE with TSMC level 49 (BSIM3v3) parametes in 0.35μm standard CMOS process.

Johan Brynolfsson - One of the best experts on this subject based on the ideXlab platform.

  • Parameter estimation of Oscillating Gaussian Functions using the scaled reassigned spectrogram
    Signal Processing, 2018
    Co-Authors: Johan Brynolfsson, Maria Sandsten
    Abstract:

    Abstract In this paper we suggest an algorithm for estimation of the parameters detailing Oscillating Gaussian Functions. The different components of the signal are first detected in the spectrogram. After this we exploit the fact that a Gaussian Function may be perfectly reassigned into one single point given a correct scaling factor, where this scaling factor is a Function of the unknown shape parameter of the Gaussian Function. The scaled reassignment of the spectrogram is performed using a set of candidate scaling factors and the local Renyi entropy is used to measure the concentration of each component using every candidate scaling factor. The estimates are refined by using non-linear least squares. The algorithm is evaluated on both simulated and real data.

  • The Scaled Reassigned Spectrogram with Perfect Localization for Estimation of Gaussian Functions
    IEEE Signal Processing Letters, 2015
    Co-Authors: Maria Hansson-sandsten, Johan Brynolfsson
    Abstract:

    The reassignment technique is used to increase localization for signal components in the time-frequency representation. The technique gives perfect localization for infinite linear chirp-signals, impulses and constant frequency signals but not for short non-stationary signals. In this paper, a scaled reassignment is proposed, based on the spectrogram using a Gaussian window. The resulting reassignment gives perfect localization for a Gaussian Function when the window length matches the Function length. Based on the scaled reassignment, an algorithm that estimates the Gaussian Function length is also proposed.

  • EUSIPCO - Parameter estimation of Gaussian Functions using the scaled reassigned spectrogram
    2015 23rd European Signal Processing Conference (EUSIPCO), 2015
    Co-Authors: Johan Brynolfsson, Maria Hansson-sandsten
    Abstract:

    In this paper we suggest an improved algorithm for estimation of parameters detailing Gaussian Functions and expand it to handle linear combinations of Gaussian Functions. Components in the signal are first detected in the spectrogram, which is calculated using a Gaussian window Function. Scaled reassignment is then performed using a set of candidate scaling factors and the local Renyi entropy is used to measure the concentration of each component using every candidate scaling factor. Exploiting the fact that a Gaussian Function may be perfectly reassigned into one single point given the correct scaling, one may identify the parameters detailing the Gaussian Function. We evaluate the algorithm on both simulated and real data.

Ali Naderi Saatlo - One of the best experts on this subject based on the ideXlab platform.

  • TSP - CMOS implementation of scalable Morlet wavelet for application in signal processing
    2015 38th International Conference on Telecommunications and Signal Processing (TSP), 2015
    Co-Authors: Ali Naderi Saatlo, Serdar Ozoguz
    Abstract:

    Implementation of Morlet wavelet using current-mode circuits is presented in CMOS technology. The circuit consists of four main building blocks: squaring circuit, exponential Function generator circuit, Gaussian Function generator circuit and analog multiplier circuit. The proposed structure is fully programmable in terms of standard deviation and peak gain of the Gaussian Function. Therefore Morlet wavelet can be programmed to define different scaling and shifting parameters. Simulation results of the circuits are obtained by HSPICE in 0.35μm standard CMOS process. Simulated results verify the feasibility of both the wavelet realization and proposed circuits.

  • on the realization of Gaussian membership Function circuit operating in saturation region
    International Conference on Telecommunications, 2015
    Co-Authors: Ali Naderi Saatlo, Serdar Ozoguz
    Abstract:

    In this paper a novel method for realization of Gaussian Function is presented. The current-mode circuits are employed for the implementation of main circuits owing to the simple circuitry and intuitive configuration. Unlike the previous works which were based on the transistors worked in weak inversion region, the proposed configuration operates in the saturation region, therefore high-accuracy as well as the highspeed performance are obtained. The proposed circuit is fully programmable in terms of mean value, standard deviation and peak gain of the Gaussian Function. Simulation results of the circuit is obtained by HSPICE with TSMC level 49 (BSIM3v3) parametes in 0.35μm standard CMOS process.

  • TSP - On the realization of Gaussian membership Function circuit operating in saturation region
    2015 38th International Conference on Telecommunications and Signal Processing (TSP), 2015
    Co-Authors: Ali Naderi Saatlo, Serdar Ozoguz
    Abstract:

    In this paper a novel method for realization of Gaussian Function is presented. The current-mode circuits are employed for the implementation of main circuits owing to the simple circuitry and intuitive configuration. Unlike the previous works which were based on the transistors worked in weak inversion region, the proposed configuration operates in the saturation region, therefore high-accuracy as well as the highspeed performance are obtained. The proposed circuit is fully programmable in terms of mean value, standard deviation and peak gain of the Gaussian Function. Simulation results of the circuit is obtained by HSPICE with TSMC level 49 (BSIM3v3) parametes in 0.35μm standard CMOS process.

Esteban Tlelo-cuautle - One of the best experts on this subject based on the ideXlab platform.

  • ISCAS (1) - Analog implementation of MOS-translinear Morlet Wavelets
    Proceedings of the 2003 International Symposium on Circuits and Systems 2003. ISCAS '03., 2003
    Co-Authors: Carlos Sánchez-lópez, Alejandro Diaz-sanchez, Esteban Tlelo-cuautle
    Abstract:

    The design of a low-voltage current-mode Morlet Wavelet, using MOS transistors in weak inversion, is presented. The proposed design is based on two translinear building blocks: a normalized Gaussian-Function generator and a four-quadrant analog-multiplier. Simulation results using BSIM3.v3 model for a 0.6 /spl mu/m AMS process parameters, in a CADENCE environment, are presented.

  • MOS-translinear Morlet wavelets
    The 2002 45th Midwest Symposium on Circuits and Systems 2002. MWSCAS-2002., 2002
    Co-Authors: Carlos Sánchez-lópez, Alejandro Diaz-sanchez, Esteban Tlelo-cuautle
    Abstract:

    The design of a low-voltage current-mode Morlet wavelet, using MOS transistors in weak inversion, is presented. The proposed design is based on two translinear building blocks: a normalized Gaussian-Function generator and a four-quadrant analog-multiplier. Simulation results using a BSIM3.v3 model for a 0.6 /spl mu/m AMS process parameters, in a CADENCE environment, are presented.