The Experts below are selected from a list of 196548 Experts worldwide ranked by ideXlab platform
V. Vasudevan - One of the best experts on this subject based on the ideXlab platform.
-
A time-Domain Technique for computation of noise-spectral density in linear and nonlinear time-varying circuits
IEEE Transactions on Circuits and Systems I-regular Papers, 2004Co-Authors: V. VasudevanAbstract:This paper presents a new time-Domain Technique for computing the noise-spectral density. The power-spectral density (PSD) is interpreted as the asymptotic value of the expected energy-spectral density per unit time. The methodology of stochastic differential equations is used to derive a set of ordinary differential equations for the expected energy-spectral density. This set of equations can then be integrated in time until the steady-state value of the PSD is obtained. The method can be used to find the noise spectrum in any circuit in which noise can be treated as a perturbation. The general nature of this algorithm has been illustrated in this paper by using it to get the noise-spectral density in switched-capacitor circuits, externally linear circuits and oscillators. The results match well with published experimental/analytical data.
-
ISCAS (1) - A time-Domain Technique for computation of noise spectral density in switched capacitor circuits
Proceedings of the 2003 International Symposium on Circuits and Systems 2003. ISCAS '03., 2003Co-Authors: V. VasudevanAbstract:This paper presents a new time Domain Technique for computing the noise spectral density. The power spectral density is interpreted as the asymptotic value of the expected energy spectral density per unit time. We show that the methodology of stochastic differential equations can be used to derive a set of ordinary differential equations for the expected energy spectral density. This set of equations can then be integrated in time until the steady state value of the power spectral density is obtained. The method is quite general and can be used to find the noise spectrum in any circuit in which noise can be treated as a perturbation. In this paper, the algorithm has been used to simulate the spectrum of the noise voltage in switched capacitor circuits.
Kazuo Hotate - One of the best experts on this subject based on the ideXlab platform.
-
Distributed measurement of Brillouin dynamic grating spectrum localized by an intensity- modulated correlation-Domain Technique.
Optics express, 2020Co-Authors: Youhei Okawa, Rodrigo Kendy Yamashita, Masato Kishi, Kazuo HotateAbstract:Higher spatial resolution of the reflection spectrum measurement of Brillouin dynamic grating (BDG) was achieved by controlling phonon power distribution. We experimentally demonstrate the improvement effect of the light-source intensity-modulation method, proposed recently in a correlation-Domain Technique, and successfully detected an 8-cm cooled section in a 100-m-long polarization-maintaining fiber. Our method can improve the spatial resolution of BDG measurements, leading to high resolution discriminative and distributed fiber sensing of temperature and strain.
-
Analysis of Brillouin dynamic grating localized by intensity-modulated correlation-Domain Technique for distributed fiber sensing.
Optics express, 2020Co-Authors: Youhei Okawa, Rodrigo Kendy Yamashita, Masato Kishi, Kazuo HotateAbstract:We numerically analyzed reflection spectrum of Brillouin dynamic grating localized by intensity-modulated correlation-Domain Technique. Furthermore, based on the results, we proposed a novel modulation Technique achieving better spatial resolution for distributed fiber sensing along a polarization-maintaining fiber.
-
Spatial Resolution Improvement of Discriminative and Distributed Measurement of Temperature/Strain with PMF using Intensity-Modulated Correlation-Domain Technique
Optical Sensors and Sensing Congress (ES FTS HISE Sensors), 2019Co-Authors: Youhei Okawa, Rodrigo Kendy Yamashita, Masato Kishi, Kazuo HotateAbstract:We numerically analyzed reflection spectrum of Brillouin dynamic grating localized by intensity-modulated correlation-Domain Technique. Then, we proposed newly modulation Technique achieving better spatial resolution for discriminative temperature/strain sensing along a PM-fiber.
-
Determination of Brillouin Dynamic Grating Spectrum Localized by the Correlation Domain Technique through Fourier Transformation
Asia Communications and Photonics Conference 2014, 2014Co-Authors: Rodrigo Kendy Yamashita, Masato Kishi, Kazuo HotateAbstract:We propose a Fourier transformation based method to calculate the shape of Brillouin dynamic grating spectrum, when the grating is localized by the correlation Domain Technique. The simulation results match with experimental data reported previously.
-
Simulation for estimating spatial resolution in distributed measurement of Brillouin dynamic grating by correlation Domain Technique
Conference on Lasers and Electro-Optics 2012, 2012Co-Authors: Rodrigo Kendy Yamashita, Kazuo HotateAbstract:We propose a simulation method to calculate reflection spectra of Brillouin dynamic grating localized by the correlation Domain Technique. Simulation results match with experiments and the spatial localization of the dynamic grating can be estimated.
L. Lucchese - One of the best experts on this subject based on the ideXlab platform.
-
a frequency Domain Technique for range data registration
IEEE Transactions on Pattern Analysis and Machine Intelligence, 2002Co-Authors: L. Lucchese, Gianfranco Doretto, G M CortelazzoAbstract:This work introduces an original method for registering pairs of 3D views consisting of range data sets which operates in the frequency Domain. The Fourier transform allows the decoupling of the estimate of the rotation parameters from the estimate of the translation parameters, our algorithm exploits this well-known property by suggesting a three-step procedure. The rotation parameters are estimated by the first two steps through convenient representations and projections of the Fourier transforms' magnitudes and the translational displacement is recovered by the third step by means of a standard phase correlation Technique after compensating one of the two views for rotation. The performance of the algorithm, which is well-suited for unsupervised registration, is clearly assessed through extensive testing with several objects and shows that good and robust estimates of 3D rigid motion are achievable. Our algorithm can be used as a prealignment tool for more accurate space-Domain registration Techniques, like the ICP algorithm.
-
a noise robust frequency Domain Technique for estimating planar roto translations
IEEE Transactions on Signal Processing, 2000Co-Authors: L. Lucchese, G M CortelazzoAbstract:This work presents a new method for estimating planar roto-translations that operates in the frequency Domain and as such, is not based on features. Since the proposed Technique uses all the image information, it is very robust against noise, it can be very accurate; estimation errors on the rotational angle varies from a few hundredths to a few tenths of a degree, depending on the noise level. Experimental evidence of this performance is presented, and the mathematical reasons behind these characteristics are explained in depth. Another remarkable feature of the algorithm consists in that it works in Cartesian coordinates, bypassing the need to transform from the Cartesian to the polar Domain, which, typically, is a numerically delicate and computationally onerous task. The proposed Technique can become an effective tool for unsupervised estimation of roto-translations by means of implementations based on FFT algorithms.
-
ICIP (1) - Free-form textured surfaces registration by a frequency Domain Technique
Proceedings 1998 International Conference on Image Processing. ICIP98 (Cat. No.98CB36269), 1Co-Authors: Guido M. Cortelazzo, Gianfranco Doretto, L. LuccheseAbstract:Free-form 3-D surfaces registration is a fundamental problem in 3-D imaging, typically approached by extensions or variations of the ICP algorithm. This work presents a new frequency Domain Technique for 3-D view registration, totally different form any other Techniques for 3-D motion estimation also, based on the Fourier transform. The proposed method can give a non-feature-based method for unsupervised registration of 3-D views. The obtained results are useful "per se" in applications targeted to visual quality or can serve as good starting point for the ICP algorithm when a higher precision is needed.
T. Itoh - One of the best experts on this subject based on the ideXlab platform.
-
Use of frequency derivatives in the three-dimensional full-wave spectral Domain Technique [microwave structures]
IEEE Transactions on Microwave Theory and Techniques, 1996Co-Authors: J. Pekarek, T. ItohAbstract:Rational function approximations are used to extrapolate the frequency response of the scattering coefficients of three-dimensional (3-D) structures. The rational functions are constructed by applying Pade approximation Techniques to single frequency solutions of the currents and the derivatives of the currents with respect to frequency. The currents and current derivatives are computed using a modified spectral Domain Technique. The efficiency of the method, along with the direct determination of the poles and zeros of the transfer function, make the method well-suited for model-based parameter estimation (MBPE). Multiple-frequency-point Pade approximations are also investigated.
-
Use of frequency derivatives in the 3D full-wave spectral Domain Technique
1996 IEEE MTT-S International Microwave Symposium Digest, 1Co-Authors: J. Pekarek, T. ItohAbstract:Rational function approximations are used to extrapolate the frequency response of scattering coefficients of 3D structures. The rational functions are constructed by applying Pade approximation Techniques to single frequency solutions of the currents and the derivatives of the currents with respect to frequency. The currents and current derivatives are computed using a modified spectral Domain Technique. The efficiency of the method, along with the direct determination of the poles and zeros of the transfer function, make the method well suited for Model-Based Parameter Estimation (MBPE). Multi-frequency-point Pade approximations are also investigated.
Jake K. Aggarwal - One of the best experts on this subject based on the ideXlab platform.
-
ICASSP - A comparsion between time- and frequency-Domain Techniques for time-varying signal processing
ICASSP '82. IEEE International Conference on Acoustics Speech and Signal Processing, 1Co-Authors: Nian-chyi Huang, Jake K. AggarwalAbstract:This paper compares the performances of time-varying digital filters designed by time- and frequency-Domain Techniques. The filter performances are compared based on the mean-square difference between the actual and the desired output sequences. Theoretically, such a comparison would favor the conventional time-Domain Technique which, however, requires much more computation time. In this paper, numerical examples are presented to illustrate the tradeoffs between the computation time and the filter performance. We show that the frequency-Domain Technique is efficient but yields suboptimal results.