effects of the poisson ratio and negative thrust on the dynamic stability of a free plate subjected to a follower force abstract the macroscopic poisson ratio of a large plate like truss structure may vary due to the geometry of the truss studied are the effects of the poisson ratio and negative thrust on the dynamic stability of a flexible rectangular plate which has four free edges one of the four edges is subjected to a tangential follower thrust the model is simplified to a continuous isotropic plate and is investigated by means of modal analysis a change in poisson ratio sometimes reduces the flutter load drastically the drastic reduction comes from the existence of a weak flutter instability it is also shown that there may exist both flutter and divergence even for negative thrust and that the tensile divergence load is smaller than the compressive one

general synthesis procedures for fir lossless transfer matrices for perfect reconstruction multirate filter bank applications a recently reported procedure see ibid vol assp 35 p 476 492 apr 1987 and proc ieee int conf acoust speech sig processing apr 1987 p 2169 2172 for the design of m channel perfect reconstruction quadrature mirror filter qmf bands uses the concept of lossless alias component matrices the synthesis of such qmf banks centers around the generation of a lossless m m finite impulse response fir transfer matrix e z recent results for such generation have been somewhat ad hoc i e not sufficiently general a general procedure is outlined for the generation of such transfer matrices the procedure is based on a cascaded lattice structure derived from a state space viewpoint the structure is such that it generates only m m lossless fir transfer matrices regardless of parameter values and conversely any m m lossless fir transfer matrix can be obtained by a suitable choice of parameters these parameters turn out to be angles theta sub k and the structure is such that the number of angles is minimal a design example is presented to demonstrate the main results

image compression based on fuzzy algorithms for learning vector quantization and wavelet image decomposition this paper evaluates the performance of an image compression system based on wavelet based subband decomposition and vector quantization the images are decomposed using wavelet filters into a set of subbands with different resolutions corresponding to different frequency bands the resulting subbands are vector quantized using the linde buzo gray 1980 algorithm and various fuzzy algorithms for learning vector quantization falvq these algorithms perform vector quantization by updating all prototypes of a competitive neural network through an unsupervised learning process the quality of the multiresolution codebooks designed by these algorithms is measured on the reconstructed images belonging to the training set used for multiresolution codebook design and the reconstructed images from a testing set

the design of weighted minimax quadrature mirror filters a technique for converting the constrained nonlinear optimization problem encountered in the design of weighted minimax quadrature mirror filters into an iterative unconstrained nonlinear optimization problem is presented this renders the design of weighted minimax quadrature mirror filters possible the technique is very efficient typically taking about seven iterations to converge a rapidly converging iterative procedure for solving the above nonlinear unconstrained optimization problem is also presented this procedure typically requires less than five iterations to converge

classical sampling theorems in the context of multirate and polyphase digital filter bank structures the recovery of a signal from so called generalized samples is a problem of designing appropriate linear filters called reconstruction or synthesis filters this relationship is reviewed and explored novel theorems for the subsampling of sequences are derived by direct use of the digital filter bank framework these results are related to the theory of perfect reconstruction in maximally decimated digital filter bank systems one of the theorems pertains to the subsampling of a sequence and its first few differences and its subsequent stable reconstruction at finite cost with no error the reconstruction filters turn out to be multiplierless and of the fir finite impulse response type these ideas are extended to the case of two dimensional signals by use of a kronecker formalism the subsampling of bandlimited sequences is also considered a sequence x n with a fourier transform vanishes for mod omega mod or l pi m where l and m are integers with l

a new look at q exponential distributions via excess statistics q exponential distributions play an important role in nonextensive statistics they appear as the canonical distributions i e the maximum generalized q entropy distributions under mean constraint their relevance is also independently justified by their appearance in the theory of superstatistics introduced by beck and cohen in this paper we provide a third and independent rationale for these distributions we indicate that q exponentials are stable by a statistical normalization operation and that pickands extreme values theorem plays the role of a clt like theorem in this context this suggests that q exponentials can arise in many contexts if the system at hand or the measurement device introduces some threshold moreover we give an asymptotic connection between excess distributions and maximum q entropy we also highlight the role of generalized pareto distributions in many applications and present several methods for the practical estimation of q exponential parameters

thermodynamics from first principles correlations and nonextensivity the standard formulation of thermostatistics being based on the boltzmann gibbs distribution and logarithmic shannon entropy describes idealized uncorrelated systems with extensive energies and short range interactions in this rapid communication we use the fundamental principles of ergodicity via liouville s theorem the self similarity of correlations and the existence of the thermodynamic limit to derive generalized forms of the equilibrium distribution for long range interacting systems significantly our formalism provides a justification for the well studied nonextensive thermostatistics characterized by the tsallis distribution which it includes as a special case we also give the complementary maximum entropy derivation of the same distributions by constrained maximization of the gibbs shannon entropy the consistency between the ergodic and maximum entropy approaches clarifies the use of the latter in the study of correlations and nonextensive thermodynamics

vibration and stability of annular plates under conservative and non conservative loads abstract this paper deals with the vibration and stability of annular plates elastically restrained against translation and rotation at the edges the plate is subjected to a horizontal or tangential radial load both axisymmetric and non axisymmetric vibrations are considered numerical results are obtained for the plate with free outside and elastically restrained inside edges when the ratio of inner to outer radius is 0 3 the flutter and divergence instability loads are obtained for a range of constraint stiffness parameters of the inside edge and are shown graphically it is found that the flutter load of a plate subjected to a follower load results from a coalescing of the m n and m 1 n modes where m and n are the number of nodal circles and nodal diameters as for the plate studied in the numerical calculation the flutter type of instability occurs for m 0 and n 0 1 2

reconstruction of signals after filtering and sampling rate reduction a wave digital filter wdf two port has two input and two output terminals by using these to appropriately connect a wdf to its transpose the filtering effect is fully compensated except for an all pass phase and this independently of any selectivity requirement this remains true if at the points of interconnection every second sample is reduced to zero provided that a certain condition easily to be satisfied exactly is fulfilled very efficient solutions are then possible the method is of interest e g for subband coding

generalized superstatistics of nonequilibrium markovian systems abstract the paper is devoted to the construction of the superstatistical description for nonequilibrium markovian systems it is based on kirchhoff s diagram technique and the assumption on the system under consideration to possess a wide variety of cycles with vanishing probability fluxes the latter feature enables us to introduce equivalence classes called channels within which detailed balance holds individually then stationary probability as well as flux distributions are represented as some sums over the channels the latter construction actually forms the superstatistical description which however deals with a certain superposition of equilibrium subsystems rather than a formal expansion of the nonequilibrium steady state distribution into terms of the boltzmann type

empirical regularities of opening call auction in chinese stock market abstract we study the statistical regularities of an opening call auction using the ultra high frequency data of 22 liquid stocks traded on the shenzhen stock exchange in 2003 the distribution of the relative price defined as the relative difference between the order price in the opening call auction and the closing price on the last trading day is asymmetric and that the distribution displays a sharp peak at the zero relative price and a relatively wide peak at the negative relative price the detrended fluctuation analysis dfa method is adopted to investigate the long term memory of relative order prices we further study the statistical regularities of order sizes in the opening call auction and observe a phenomenon of number preference known as order size clustering the probability density function pdf of order sizes could be well fitted by a q gamma function and the long term memory also exists in order sizes in addition both the average volume and the average number of orders decrease exponentially with the price level away from the best bid or ask price level in the limit order book lob established immediately after the opening call auction and a price clustering phenomenon is observed

the infinite number of generalized dimensions of fractals and strange attractors abstract we show that fractals in general and strange attractors in particular are characterized by an infinite number of generalized dimensions dq q 0 to this aim we develop a rescaling transformation group which yields analytic expressions for all the quantities dq we prove that lim q 0 dq fractal dimension d limq 1dq information dimension and dq 2 correlation exponent v dq with other integer q s correspond to exponents associated with ternary quaternary and higher correlation functions we prove that generally dq dq for any q q for homogeneous fractals dq dq a particularly interesting dimension is dq for two examples feigenbaum attractor generalized baker s transformation we calculate the generalized dimensions and find that d is a non trivial number all the other generalized dimensions are bounded between the fractal dimension and d

monotonically equivalent entropies and solution of additivity equation generalized entropies are studied as lyapunov functions for the master equation markov chains three basic properties of these lyapunov functions are taken into consideration universality independence of the kinetic coefficients trace form the form of sum over the states and additivity for composition of independent subsystems all the entropies which have all three properties simultaneously and are defined for positive probabilities are found they form a one parametric family we consider also pairs of entropies s1 s2 which are connected by the monotonous transformation s2 f s1 equivalent entropies all classes of pairs of universal equivalent entropies one of which has a trace form and another is additive these entropies can be different one from another were found these classes consist of two one parametric families the family of entropies which are equivalent to the additive trace form entropies and the family of renyi tsallis entropies

entropy and complexity analysis of dirac delta like quantum potentials abstract the dirac delta like quantum mechanical potentials are frequently used to describe and interpret numerous phenomena in many scientific fields including atomic and molecular physics condensed matter and quantum computation the entropy and complexity properties of potentials with one and two dirac delta functions are here analytically calculated and numerically discussed in both position and momentum spaces we have studied the information theoretic lengths of fisher renyi and shannon types as well as the cramer rao fisher shannon and lmc shape complexities of the lowest lying stationary states of one delta and twin delta they allow us to grasp and quantify different facets of the spreading of the charge and momentum of the system far beyond the celebrated standard deviation

derivation of power law distributions within standard statistical mechanics abstract we show that within classical statistical mechanics it is possible to naturally derive power law distributions which are of tsallis type the only assumption is that microcanonical distributions have to be separable from of the total system energy which is reasonable for any sensible measurement we demonstrate that all separable distributions are parametrized by a separation constant q which is one to one related to the q parameter in tsallis distributions the power laws obtained are formally equivalent to those obtained by maximizing the tsallis entropy under q constraints we further ask why nature fixes the separation constant q to 1 in so many cases leading to standard thermodynamics we answer this with an explicit example where it is possible to relate q to system size and interaction parameters characterizing the physical system we argue that these results might be helpful to explain the ubiquity of tsallis distributions in nature

vibration and stability of elasticity supported circular plates under conservative and non conservative loads abstract this paper deals with the vibration and stability of circular plates elastically restrained against translation and rotation along concentric intermediate circles as well as at the outer edge the plate is subjected to a horizontal or tangential radial load at the periphery both axisymmetric and non axisymmetric vibrations are considered it is assumed that the plate is thin elastic and isotropic the solutions are obtained in terms of bessel functions for both the complete and annular plate sections the effect of the support stiffnesses on the plate natural frequency and the divergence and flutter instability loads are studied in detail

polyphase networks block digital filtering lptv systems and alias free qmf banks a unified approach based on pseudocirculants the relationship between block digital filtering and quadrature mirror filter qmf banks is explored necessary and sufficient conditions for alias cancellation in qmf banks are expressed in terms of an associated matrix derived from the polyphase components of the analysis and synthesis filters these conditions called the pseudocirculant conditions make it possible to unite qmf banks with the framework of block digital filtering directly absence of amplitude distortion in an alias free qmf bank translates into the losslessness property of the pseudocirculant matrix involved

fractal surfaces from simple arithmetic operations fractal surfaces patchwork quilts are shown to arise under most general circumstances involving simple bitwise operations between real numbers a theory is presented for all deterministic bitwise operations on a finite alphabet it is shown that these models give rise to a roughness exponent h that shapes the resulting spatial patterns larger values of the exponent leading to coarser surfaces

generalized kolmogorov entropy in the dynamics of multifractal generation abstract we point out that applying a maximization principle on a tsallis like generalized form of the kolmogorov entropy for iterated function systems naturally provides a canonical statistical frame for the description of the multifractal measures generated by such dynamical processes multifractal spectra can then be characterized by usual statistical parameters in particular the temperature we show that in the limit of zero temperature the multifractal measure collapses to a homogeneous distribution over a fractal support for finite temperatures multifractal spectra are studied numerically in an illustrative example

possible generalization of boltzmann gibbs statistics with the use of a quantity normally scaled in multifractals a generalized form is postulated for entropy namelys q k 1 i 1 w p i q q 1 whereq characterizes the generalization andp i are the probabilities associated withw microscopic configurations w the main properties associated with this entropy are established particularly those corresponding to the microcanonical and canonical ensembles the boltzmann gibbs statistics is recovered as theq 1 limit

an efficient iterative algorithm for designing optimal recursive digital filters a new iterative algorithm is presented for the efficient design of unconstrained and constrained infinite impulse response iir digital filters both in the unconstrained and constrained cases the numerator and denominator of the filter transfer function are designed iteratively by recourse to the remez algorithm and to appropriate design parameters and criteria at each iteration this makes it possible for the algorithm to be implemented by means of a short main program which uses at each iteration the finite impulse response fir filter design algorithm of mcclellan et al as a subroutine as a consequence the entire design procedure proves to be very efficient the approach taken also permits the filter to be designed with a desired passband to stopband ripple ratio typically the design algorithm converges to the optimal solution within a few iterations several examples are given to illustrate the procedure the filter design computer program is provided in the appendix

generalized boltzmann factors and the maximum entropy principle entropies for complex systems abstract we generalize the usual exponential boltzmann factor to any reasonable and potentially observable distribution function b e by defining generalized logarithms as inverses of these distribution functions we are led to a generalization of the classical boltzmann gibbs entropy s bg d e e b e ln b e to the expression s d e e 0 b e d x x which contains the classical entropy as a special case we show that this is the unique modification of entropy which is compatible with the maximum entropy principle for arbitrary non exponential distribution functions we demonstrate that this entropy has two important features first it describes the correct thermodynamic relations of the system and second the observed distributions are straightforward solutions to the jaynes maximum entropy principle with the ordinary not escort constraints tsallis entropy is recovered as a further special case

disequilibrium complexity the schottky effect and q entropies in paramagnetism abstract we investigate connections between statistical quantifiers and paramagnetism more concretely we apply the notions of i disequilibrium and ii statistical complexity to a paramagnetic system of non coupled dipoles interesting insights are thereby obtained in particular we encounter a kind of criticality not associated to the temperature but to the disequilibrium

dynamic stability of a completely free plate subjected to a controlled non conservative follower force abstract the dynamic instability of a rectangular plate with four free edges is investigated one edge of the completely free plate is subjected to a uniformly distributed non conservative follower force the direction of which is controlled in proportion to the rotation angle of the loading edge the plate may have both flutter and divergence type instabilities when the force is non conservative although it may have only divergence type instabilities when the force is conservative

on the stability of generalized entropies by the use of a probabilistic coupling technique and generalizing a recent result of zhang 2007 lett math phys 80 171 we derive several sharp inequalities concerning the uniform continuity of some generalized entropies these inequalities capture certain aspects of the interplay between the entropies and the uniform distance variational distance and establish the stability of the involved entropies

theory and design of m channel maximally decimated quadrature mirror filters with arbitrary m having the perfect reconstruction property based on the concept of losslessness in digital filter structures this paper derives a general class of maximally decimated m channel quadrature mirror filter banks that lead to perfect reconstruction the perfect reconstruction property guarantees that the reconstructed signal hat x n is a delayed version of the input signal x n i e hat x n x n n 0 it is shown that such a property can be satisfied if the alias component matrix ac matrix for short is unitary on the unit circle of the z plane the number of channels m is arbitrary and when m is two the results reduce to certain recently reported 2 channel perfect reconstruction qmf structures a procedure based on recently reported fir cascaded lattice structures is presented for optimal design of such fir m channel filter banks design examples are included

stability of a rectangular plate under nonconservative and conservative forces abstract a study is made of the flutter and divergence instabilities of a rectangular plate with two independent loading parameters the plate is subjected to the combined action of a tangential follower force and a unidirectional axial force along one edge two opposite sides of the plate are simply supported one side being clamped and the other being a free edge where the in plane forces act depending on the relative magnitudes of the follower and axial forces the plate may lose its stability by flutter or divergence the flutter problem is solved by maximizing the flutter load over the frequency and thereby obtaining the maximum point of an eigencurve the stability boundaries are given for plates with different aspect ratios the two dimensional nature of the problem reveals some interesting results not observed in the one dimensional counterpart of the problem which is a cantilevered column under vertical and follower forces the effect of an elastic foundation on the stability boundaries are determined the influence of poisson s ratio on the flutter load and frequency is investigated it is shown that no general rule can be formulated as to the effect of poisson s ratio on the flutter load and that this effect will vary according to the aspect ratio and axial load

indices for testing neural codes one of the most critical challenges in systems neuroscience is determining the neural code a principled framework for addressing this can be found in information theory with this approach one can determine whether a proposed code can account for the stimulus response relationship specifically one can compare the transmitted information between the stimulus and the hypothesized neural code with the transmitted information between the stimulus and the behavioral response if the former is smaller than the latter i e if the code cannot account for the behavior the code can be ruled out the information theoretic index most widely used in this context is shannon s mutual information the shannon test however is not ideal for this purpose while the codes it will rule out are truly nonviable there will be some nonviable codes that it will fail to rule out here we describe a wide range of alternative indices that can be used for ruling codes out the range includes a continuum from shannon information to measures of the performance of a bayesian decoder we analyze the relationship of these indices to each other and their complementary strengths and weaknesses for addressing this problem

least squares approximation of perfect reconstruction filter banks designing good causal filters for perfect reconstruction pr filter banks is a challenging task due to the unusual nature of the design constraints we present a new least squares ls design methodology for approximating prfbs that avoids most of these difficult constraints the designer first selects a set of subband analysis filters from an almost unrestricted class of rational filters then given some desired reconstruction delay this design procedure produces the causal and rational synthesis filters that result in the best least squares approximation to a prfb this technique is built on a multi input multi output mimo system model for filter banks derived from the filter bank polyphase representation using this model we frame the ls approximation problem for prfbs as a causal ls equalization problem for mimo systems we derive the causal ls solution to this design problem and present an algorithm for computing this solution the resulting algorithm includes a mimo spectral factorization that accounts for most of the complexity and computational cost for this design technique finally we consider some design examples and evaluate their performance

new quadrature mirror filter structures this paper introduces new quadrature mirror filter qmf structures for the frequency domain analysis and synthesis of digital signals the conventional qmf technique is first extended to cover complex quadrature mirror filters cqmf in which a digital signal is split into n adjacent complex subbands where the real and imaginary parts are subsampled by 1 2n with respect to the original signal the computational complexity of qmf banks is then analyzed and a new scheme which reduces the computational complexity by about a factor of two over conventional qmf implementations is proposed finally the filter design tradeoffs are discussed and the microprogramed implementation of qmf banks is evaluated

some properties of q logarithm and q exponential functions in tsallis statistics we present some formulae which q logarithmic and q exponential functions introduced in tsallis statistics satisfy exact expression of the mellin transform of q exponential function is given moreover the q generalization of the digamma function is presented

determination of the steady state response of a viscoelastically point supported rectangular plate the steady state response to a sinusoidally varying force is determined for a viscoelastically point supported square or rectangular plate for this purpose the transverse deflection of the plate is written in a series of the product of the deflection functions of beams parallel to the edges and the response equation is derived by the generalized galerkin method the natural boundary conditions of the plate which cannot be satisfied by the beam functions at the edges and the corners are appropriately compensated by suitable additions to the residual forces and moments the method is applied to a square plate supported at four points symmetrically located at the corners or on the diagonals the steady state response of the plate to a point force acting at the centre is calculated numerically and the effects of the point supports on the vibration are studied

a class of efficient recursive quadrature mirror filters for subband coding a class of recursive quadrature mirror filters qmfs of the form h z n z d z sup 2 is proposed for subband coding these filters can be efficiently designed with the iterative remez exchange algorithm simple modifications are made to the pei see ieee trans circuits syst vol cas 36 no 2 p 311 1989 liang mcclellan and parks computer program for designing these recursive qmf filters efficiently the resulting filters totally eliminate the aliasing terms and can achieve almost perfect magnitude reconstruction with 131 5 db distortion a design example is presented to show the effectiveness of this approach

a new approach to recursive mirror filters with a special application in subband coding of images a novel method for applying recursive mirror filters rmf in applications where infinite delay can be tolerated is presented this type of situation can be found in several circumstances but the method has its main applications in a technique of subband coding of images which was presented by j w woods and s d o neill ibid vol assp 34 p 1278 88 oct 1986 in image coding a delay is only a shift in a spatial coordinate the present method has looser filter constraints than previous recursive quadrature mirror filter qmf techniques but may in certain applications require a large memory contrary to earlier recursive qmf techniques this approach leads to a linear phase characteristic a property that is vital in image coding

path integral approach to the nonextensive canonical density matrix abstract feynman s path integral is herein generalized to the nonextensive canonical density matrix based on tsallis entropy this generalization is done in two ways by using unnormalized and normalized constraints firstly we consider the path integral formulation with unnormalized constraints and this generalization is worked out through two different ways which are shown to be equivalent these formulations with unnormalized constraints are solutions to the two generalized bloch equations proposed in this work the first form of the generalized bloch equation is linear but with a temperature dependent effective hamiltonian the second form is nonlinear and resembles the anomalous correlated diffusion equation porous medium equation furthermore we can extend these results to the prescription of field theory using integral representations the second development is dedicated to analyzing the path integral formulation with normalized constraints to illustrate the methods introduced here we analyze the free particle case and a non interacting scalar field the results herein obtained are expected to be useful in the discussion of generic nonextensive contexts

convergence in reaction diffusion systems an information theory approach abstract we have applied an information theory approach in order to study the problem of convergence to point like or extended attractors in reaction diffusion systems a distance between two states based on the kullback leibler relative information was defined different forms of the probability distribution some of them based on the knowledge of the nonequilibrium potential when accesible give the possibility to look for a faster and or more accurate convergence this approach offers the chance to estimate the attraction basins of the different attractors as well as detecting limit circles together with an easy evaluation of their periods

diffusion on fractal phase spaces and entropy production abstract complex systems may show strongly non exponential relaxation the origins of these behavior seem to be related to the fractal structure of the phase space in this article we consider the diffusion on a dilute hypercube this stochastic process is a coarse grained model for the time evolution of a glassy system where both the dynamics and the structure of the phase space was considered as simple as possible we characterize this process using two quantities a memory function and the tsallis entropy the first one is a measure of mixing while the second is related to non extensivity we characterize quantitatively their relationship finally we discuss the implications for other glassy and complex systems

recursive quadrature mirror filters criteria specification and design method criteria are found for a pair of recursive infinite impluse response iir filters which have mirror image amplitude responses and whose outputs are in phase quadrature at all frequencies a method is suggested for designing filters with these characteristics and their performance and processing requirements are compared with a typical nonrecursive finite impluse response fir realization a particular filter is described in more detail and it is shown how it could be incorporated in a multiband processing scheme it is concluded that recursive quadrature mirror filters could offer considerable savings in terms of signal processing compared with nonrecursive filters with similar performances additionally it is suggested that because they can be designed to have relatively short absolute delays the performance of the iir filters may prove superior for certain applications

running fir and iir filtering using multirate filter banks the computational complexity of running fir finite impulse response and iir infinite impulse response filtering using multirate filter banks is considered no restrictions are put on signal filter or block lengths it is shown how to map long running convolutions into smaller ones by using filter banks based on aperiodic convolution algorithms and short time fourier transforms with the proposed approach good tradeoffs among computational complexity system architecture and input output delay are achieved

design of finite impulse response digital filters with nonlinear phase response most of the existing literature on fir digital filters is concerned with linear phase lp filters however several papers have appeared on the subject of nonlinear phase nlp filters mainly proposing methods for designing minimum phase filters or approximating a desired phase response in this paper an investigation is made of one such method based upon a selection of zeros from a prototype lp filter it is shown that with respect to minimizing the order of a filter subject to given gain response specifications this is the most efficient method for designing fir filters coefficient quantization error is analyzed for filters generated by this method a practical comparison is given between the resulting filter and the corresponding minimal order lp filter it is shown that while most lp filters can be implemented more efficiently than nlp filters by taking into account the symmetry of their coefficients for filters with very wide passband and for certain special purpose filters such as ccd and those used for filtering a delta modulated or adpcm signal an nlp implementation is usually more efficient in addition an alternate design algorithm is proposed for nlp filters which decreases ripple magnitude the resulting filters while not of minimal order can be efficiently implemented by decomposing the filter into lp stopband and nlp passband sections which is especially attractive for narrow passbands

generalized digital butterworth filter design this correspondence introduces a new class of infinite impulse response iir digital filters that unifies the classical digital butterworth filter and the well known maximally flat fir filter new closed form expressions are provided and a straightforward design technique is described the new iir digital filters have more zeros than poles away from the origin and their monotonic square magnitude frequency responses are maximally flat at spl omega 0 and at spl omega spl pi another result of the correspondence is that for a specified cutoff frequency and a specified number of zeros there is only one valid way in which to split the zeros between z 1 and the passband this technique also permits continuous variation of the cutoff frequency iir filters having more zeros than poles are of interest because often to obtain a good tradeoff between performance and implementation complexity just a few poles are best

student s t and r distributions unified derivation from an entropic variational principle abstract the optimization of the recently generalized entropy of the form s q 1 dx p x q q 1 with the constraints dx p x 1 and x 2 q dx x 2 p x q 1 yields the student s t distribution for q 1 and the r distribution for q

structures for m channel perfect reconstruction fir qmf banks which yield linear phase analysis filters the authors develop structures for fir finite impulse response perfect reconstruction qmf quadrature mirror filter banks which cover a subclass of systems that yield linear phase analysis filters for arbitrary m the parameters of these structures can be optimized to design analysis filters with minimum stopband energy which at the same time have linear phase and satisfy the perfect reconstruction property if there are m subbands then depending on whether the coefficients h sub k n of each analysis filter are symmetric or antisymmetric several combinations of filter banks are possible some of these permit perfect reconstruction and some do not for a given m the authors develop a formula for the number of combinations for a subclass of linear phase perfect reconstruction structures as an example they elaborate on a perfect reconstruction linear phase lattice structure for three channels the lattice structure is such that regardless of the parameter values the qmf bank enjoys the perfect reconstruction property while at the same time the analysis filters have linear phase a design example is presented along with tables of impulse response coefficients

improved technique for design of perfect reconstruction fir qmf banks with lossless polyphase matrices a technique is developed for the design of analysis filters in an m channel maximally decimated perfect reconstruction finite impulse response quadrature mirror filter fir qmf bank that has a lossless polyphase component matrix e z the aim is to optimize the parameters characterizing e z until the sum of the stopband energies of the analysis filters is minimized there are four novel elements in the procedure reported here the first is a technique for efficient initialization of one of the m analysis filters as a spectral factor of an mth band filter the factorization itself is done in an efficient manner using the eigenfilters approach without the need for root finding techniques the second element is the initialization of the internal parameters which characterize e z based on the above spectral factor the third element is a modified characterization mostly free from rotation angles of the fir e z the fourth is the incorporation of symmetry among the analysis filters so as to minimize the number of unknown parameters being optimized the resulting design procedure always gives better filter responses than earlier ones for a given filter length and converges much faster

fractal structure with a typical scale in order to understand the characteristics common to distributions which have both fractal and non fractal scale regions in a unified framework we introduce the concept of a typical scale we employ a model of 2d gravity modified by the r2 term as a tool to understand such distributions through the typical scale this model is obtained by adding an interaction term with a typical scale to a scale invariant system a distribution derived in the model provides power law one in the large scale region but weibull like one in the small scale region as examples of distributions which have both fractal and non fractal regions we take those of personal income and citation number of scientific papers we show that these distributions are fitted fairly well by the distribution curves derived analytically in the r2 2d gravity model as a result we consider that the typical scale is a useful concept to understand various distributions observed in the real world in a unified way we also point out that the r2 2d gravity model provides us with an effective tool to read the typical scales of various distributions in a systematic way

design of iir linear phase qmf banks based on complex allpass sections a new method for the design of two channel perfect reconstruction analysis synthesis qmf banks is presented the filters of the banks are iir power complementary linear phase and are represented by means of complex allpass functions design procedures based both on numerical approximation and on a flatness constraint imposed on the frequency responses of the filters are given

multiwavelet packet entropy and its application in transmission line fault recognition and classification multiwavelets possess better properties than traditional wavelets multiwavelet packet transformation has more high frequency information spectral entropy can be applied as an analysis index to the complexity or uncertainty of a signal this paper tries to define four multiwavelet packet entropies to extract the features of different transmission line faults and uses a radial basis function rbf neural network to recognize and classify 10 fault types of power transmission lines first the preprocessing and postprocessing problems of multiwavelets are presented shannon entropy and tsallis entropy are introduced and their difference is discussed second multiwavelet packet energy entropy time entropy shannon singular entropy and tsallis singular entropy are defined as the feature extraction methods of transmission line fault signals third the plan of transmission line fault recognition using multiwavelet packet entropies and an rbf neural network is proposed finally the experimental results show that the plan with the four multiwavelet packet energy entropies defined in this paper achieves better performance in fault recognition the performance with sa4 symmetric antisymmetric multiwavelet packet tsallis singular entropy is the best among the combinations of different multiwavelet packets and the four multiwavelet packet entropies

maximum entropy approach to power law distributions in coupled dynamic stochastic systems statistical properties of coupled dynamic stochastic systems are studied within a combination of the maximum information principle and the superstatistical approach the conditions at which the shannon entropy functional leads to power law statistics are investigated it is demonstrated that from a quite general point of view the power law dependencies may appear as a consequence of global constraints restricting both the dynamic phase space and the stochastic fluctuations as a result at sufficiently long observation times the dynamic counterpart is driven into a nonequilibrium steady state whose deviation from the usual exponential statistics is given by the distance from the conventional equilibrium

chebyshev design of filters for subband coders linear phase and minimum phase quadrature mirror filters with prescribed stopband attenuation and optimum reconstruction error are designed by linear programming the variation of the reconstruction error as a function of the filter is investigated on an example

lattice structures for optimal design and robust implementation of two channel perfect reconstruction qmf banks a lattice structure and an algorithm are presented for the design of two channel qmf quadrature mirror filter banks satisfying a sufficient condition for perfect reconstruction the structure inherently has the perfect reconstruction property while the algorithm ensures a good stopband attenuation for each of the analysis filters implementations of such lattice structures are robust in the sense that the perfect reconstruction property is preserved in spite of coefficient quantization the lattice structure has the hierarchical property that a higher order perfect reconstruction qmf bank can be obtained from a lower order perfect reconstruction qmf bank simply by adding more lattice sections several numerical examples are provided in the form of design tables

zeroth law compatibility of nonadditive thermodynamics nonextensive thermodynamics is criticized by the statement that the zeroth law cannot be satisfied with nonadditive composition rules corrected in this paper we determine the general functional form of those nonadditive composition rules that are compatible with the zeroth law of thermodynamics we find that this general form is additive for the formal logarithms of the original quantities and the familiar relations of thermodynamics apply to these our result offers a possible solution to the long standing questions about equilibrium between extensive and nonextensive systems or systems with different nonextensivity parameters

tsallis like information measures and the analysis of complex signals abstract a tsallis like information measure that elaborates upon those of the tsallis type is shown to be a rather powerful tool for the analysis of complex non stationary signals as exemplified by the henon map and eegs the ensuing results could be of importance concerning the automatic detection of epileptic spikes

subband coder design incorporating recursive quadrature filters and optimum adpcm coders this paper presents the results of an analytical and experimental study of the use of iir quadrature mirror filters and forward adapting adpcm with optimum quantizers for octave band subband coders for speech it is shown that the underlying analysis synthesis systems can be designed such that there is no interband aliasing distortion in the coded speech and such that the analysis synthesis transfer function has no frequency distortion or no phase distortion but not both the experimental study showed that subband coders based on a mixture of infinite impulse response iir and finite duration impulse response fir filters resulted in higher quality coding systems using fewer multiplies than for systems based on fir filters alone it was also found that a signal to noise ratio snr gain of about 4 db could be obtained using optimum quantizers for forward adapting adpcm coders over linear quantizers in backward adapting apcm codes but no perceptual quality gain was observed

on the derivation of power law distributions within classical statistical mechanics far from the thermodynamic limit we show that within classical statistical mechanics without taking the thermodynamic limit the most general boltzmann factor for the canonical ensemble is a q exponential function the only assumption here is that microcanonical distributions have to be separated from the total system energy which is the prerequisite for any sensible measurement we derive that all separable distributions are parametrized by a mathematical separation constant q which can be related to the non extensivity q parameter in tsallis distributions we further demonstrate that nature fixes the separation constant q to 1 for large dimensionality of gibbs phase space our results will be relevant for systems with a low dimensional space for example nanosystems comprised of a small number of particles or for systems with a dimensionally collapsed phase space which might be the case for a large class of complex systems

extracting features of gaussian self similar stochastic processes via the bandt pompe approach by recourse to appropriate information theory quantifiers normalized shannon entropy and martin plastino rosso intensive statistical complexity measure we revisit the characterization of gaussian self similar stochastic processes from a bandt pompe viewpoint we show that the ensuing approach exhibits considerable advantages with respect to other treatments in particular clear quantifiers gaps are found in the transition between the continuous processes and their associated noises

subband decomposition an lms based algorithm to approximate the perfect reconstruction bank in the general case an algorithm based on least mean squares lms is described given an arbitrary invertible decomposition decimation process the algorithm will find the finite impulse response reconstruction filters which best approximate the perfect reconstruction ones by allowing the reconstruction filters impulse responses to be sufficiently long the quality of the approximation can be made as good as required two examples are presented for the implementation of this algorithm one in the case of a decomposition by a filter bank of galand 1977 where the reconstruction bank is already known the other in the situation of a two subband decomposition where one of the subbands covers two thirds of the frequency space and the other covers the remaining one third

a theory for multiresolution signal decomposition the wavelet representation multiresolution representations are effective for analyzing the information content of images the properties of the operator which approximates a signal at a given resolution were studied it is shown that the difference of information between the approximation of a signal at the resolutions 2 sup j 1 and 2 sup j where j is an integer can be extracted by decomposing this signal on a wavelet orthonormal basis of l sup 2 r sup n the vector space of measurable square integrable n dimensional functions in l sup 2 r a wavelet orthonormal basis is a family of functions which is built by dilating and translating a unique function psi x this decomposition defines an orthogonal multiresolution representation called a wavelet representation it is computed with a pyramidal algorithm based on convolutions with quadrature mirror filters wavelet representation lies between the spatial and fourier domains for images the wavelet representation differentiates several spatial orientations the application of this representation to data compression in image coding texture discrimination and fractal analysis is discussed