Search results for "Autocorrelation"
showing 10 items of 146 documents
A Highly Flexible Trajectory Model Based on the Primitives of Brownian Fields—Part II: Analysis of the Statistical Properties
2016
In the first part of our paper, we have proposed a highly flexible trajectory model based on the primitives of Brownian fields (BFs). In this second part, we study the statistical properties of that trajectory model in depth. These properties include the autocorrelation function (ACF), mean, and the variance of the path along each axis. We also derive the distribution of the angle-of-motion (AOM) process, the incremental traveling length process, and the overall traveling length. It is shown that the path process is in general non-stationary. We show that the AOM and the incremental traveling length processes can be modeled by the phase and the envelope of a complex Gaussian process with no…
Autocorrelation in meter induction: the role of accent structure.
2006
The performance of autocorrelation-based meter induction was tested with two large collections of folk melodies, consisting of approximately 13 000 melodies for which the correct meters were available. The performance was measured by the proportion of melodies whose meter was correctly classified by a discriminant function. Furthermore, it was examined whether including different melodic accent types would improve the classification performance. By determining the components of the autocorrelation functions that were significant in the classification it was found that periodicity in note onset locations was the most important cue for the determination of meter. Of the melodic accents includ…
Modeling of Vehicle-to-Vehicle Channels in the Presence of Moving Scatterers
2012
In this paper, we derive a vehicle-to-vehicle~(V2V) channel model assuming a typical propagation scenario in which the local scatterers move with random velocities in random directions. The complex channel gain of the proposed V2V channel model is provided. Subsequently, for different scatterer velocity distributions, the corresponding autocorrelation functions~(ACFs) are derived, illustrated, and compared with the classical ACF derived under the assumption of fixed scatterers. Furthermore, under specific conditions, highly accurate approximations for the ACFs are provided in closed form. Since the proposed V2V channel model covers several communication scenarios as special cases, including…
ChemInform Abstract: Specific Heat of Amorphous Silica within the Harmonic Approximation.
2010
We investigate to what extent the specific heat of amorphous silica can be calculated within the harmonic approximation. For this we use molecular dynamics computer simulations to calculate, for a simple silica model (the BKS potential), the velocity autocorrelation function and hence an effective density of states g(ν). We find that the harmonic approximation is valid for temperatures below 300 K but starts to break down at higher temperatures. We show that, to obtain a reliable description of the low-frequency part of g(ν), i.e., where the boson peak is observed, it is essential to use large systems for the simulations and small cooling rates to quench the samples. We find that the calcul…
Specific Heat of Amorphous Silica within the Harmonic Approximation
1999
We investigate to what extent the specific heat of amorphous silica can be calculated within the harmonic approximation. For this we use molecular dynamics computer simulations to calculate, for a simple silica model (the BKS potential), the velocity autocorrelation function and hence an effective density of states g(ν). We find that the harmonic approximation is valid for temperatures below 300 K but starts to break down at higher temperatures. We show that, to obtain a reliable description of the low-frequency part of g(ν), i.e., where the boson peak is observed, it is essential to use large systems for the simulations and small cooling rates to quench the samples. We find that the calcul…
Towards unsupervised analysis of second-order chromatographic data: automated selection of number of components in multivariate curve-resolution meth…
2007
A method to apply multivariate curve-resolution unattendedly is presented. The algorithm is suitable to perform deconvolution of two-way data (e.g. retrieving the individual elution profiles and spectra of co-eluting compounds from signals obtained from a chromatograph equipped with multiple-channel detection: LC-DAD or GC-MS). The method is especially adequate to achieve the advantages of deconvolution approaches when huge amounts of data are present and manual application of multivariate techniques is too time-consuming. The philosophy of the algorithm is to mimic the reactions of an expert user when applying the orthogonal projection approach--multivariate curve-resolution techniques. Ba…
Photon antibunching in the optical near field
2010
International audience; We show that a combination of the field-susceptibility technique with the optical Bloch equations gives access to the temporal evolution of the populations and coherences of any quantum system placed in the optical near field of a nanostructure. In particular, we show that the near-field evanescent states, confined around dielectric or plasmonic particles, can be used to modify and control the photon statistics of the quantum system. This theoretical scheme leads to second-order autocorrelation functions in good agreement with recent experimental measurements performed with nitrogen-vacancy center in diamond nanocrystals placed in interaction with gold nanoparticles.
A narrowband MIMO car-to-car channel model based on the geometrical street scattering model
2012
In this paper, we model a narrowband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. In the proposed channel model, an infinite number of scatterers are uniformly distributed in rectangular grids located on both sides of the street. Analytical solutions are presented for the three-dimensional (3D) space-time cross-correlation function (CCF), the temporal autocorrelation function (ACF), and the two-dimensional (2D) space CCF. An …
The design of sum-of-cisoids channel simulators using the iterative nonlinear least square approximation method
2013
In this paper, we propose the iterative nonlinear least square approximation (INLSA) algorithm as an effective method for the design of sum-of-cisoids (SOC) channel simulators assuming non-isotropic scattering conditions. For the characterization of non-isotropic scattering scenarios, we use the von Mises distribution for describing the distribution of the angles-of-arrival (AOAs). The INLSA method relies partially on numerical optimization techniques. This method determines the SOC model parameters iteratively by minimizing the Frobenius error norm. We evaluate the performance of the INLSA method and compare the results with those obtained for the Riemann sum method (RSM) and the Lp-norm m…
All-optical measurements of background, amplitude, and timing jitters for high speed pulse trains or PRBS sequences using autocorrelation function
2008
International audience; We present a simple method for all-optical measurements of background, amplitude, and timing jitters of ultra high speed pulse trains or PRBS sequences using the jitter dependence of the intercorrelation-peak shape. This method is numerically and experimentally demonstrated on a 42.66 Gbit/s PRBS sequence and then applied to measure the jitter growths occurring during the propagation of a 160-GHz pulse train in a classical SMF/DCF dispersion map.