determination of the mutual radiation resistances of a rectangular plate and their impact on the radiated sound power abstract the mutual radiation resistances resulting from cross modal coupling have been mostly excluded from sound power calculations on the belief or premise that either for some reasons they have an insignificant impact on the power radiation or consideration of them can be an enormous computational burden in this paper the characteristics of the mutual radiation resistances are investigated of a simply supported rectangular plate it is shown that once the self radiation resistances or the so called modal radiation efficiencies have been calculated the mutual radiation resistances can be readily obtained at virtually no cost of equal importance because no approximation is made the present formulation is fully accurate in the entire frequency range an asymptotic expression is also derived for large modal wavenumbers numerical results are presented to illustrate the spectral characteristics of the mutual radiation resistances and the corresponding impact on the radiated sound power

some new characterizations of dirichlet type spaces on the unit ball of cn abstract the dirichlet type spaces on the unit ball of c n are characterized by some oscillations in the bergman metric in this paper as an application of these new characterizations of dirichlet type spaces we prove that composition operators induced by biholomorphic maps are bounded on d p 1 p n

synchronization and desynchronization in a network of locally coupled wilson cowan oscillators a network of wilson cowan wc oscillators is constructed and its emergent properties of synchronization and desynchronization are investigated by both computer simulation and formal analysis the network is a 2d matrix where each oscillator is coupled only to its neighbors we show analytically that a chain of locally coupled oscillators the piecewise linear approximation to the wc oscillator synchronizes and we present a technique to rapidly entrain finite numbers of oscillators the coupling strengths change on a fast time scale based on a hebbian rule a global separator is introduced which receives input from and sends feedback to each oscillator in the matrix the global separator is used to desynchronize different oscillator groups unlike many other models the properties of this network emerge from local connections that preserve spatial relationships among components and are critical for encoding gestalt principles of feature grouping the ability to synchronize and desynchronize oscillator groups within this network offers a promising approach for pattern segmentation and figure ground segregation based on oscillatory correlation

a network of oscillators a model of neuronal behaviour capable of accounting for the oscillatory plateau and rebound properties of biological neurons is derived discussed and analysed the model is based on a piecewise linear form of the fitzhugh nagumo equations but reduces to a set of maps very similar to those of the hopfield model 1982 in particular the binary description of individual neurons and the well studied form of the synaptic current sigma jijsj are preserved although the model is capable of reproducing behaviours on the slow timescales characteristic of plateau and oscillation by coupling two model cells together a mutually inhibitory or half centred oscillator and an oscillator fixed phase follower pairs are constructed

nonlinear dynamics of pattern formation and pattern recognition in the rabbit olfactory bulb abstract a mathematical model of the process of pattern recognition in the first olfactory sensory cortex of the rabbit is presented it explains the formation and alteration of spatial patterns in neural activity observed experimentally during classical pavlovian conditioning on each inspiration of the animal a surge of receptor input enters the olfactory bulb eeg activity recorded at the surface of the bulb undergoes a transition from a low amplitude background state of temporal disorder to coherent oscillation there is a distinctive spatial pattern of rms amplitude in this oscillation which changes reliably to a second pattern during each successful recognition by the animal of a conditioned stimulus odor when a new odor is paired as conditioned stimulus these patterns are replaced by new patterns that stabilize as the animal adapts to the new environment i will argue that a unification of the theories of pattern formation and associative memory is required to account for these observations this is achieved in a model of the bulb as a discrete excitable medium with spatially inhomogeneous coupling expressed by a connection matrix the theory of multiple hopf bifurcations is employed to find coupled equations for the amplitudes of competing unstable oscillatory modes these may be created in the system by proper coupling and selectively evoked by specific classes of inputs this allows a view of limit cycle attractors as stored fixed points of a gradient vector field and thereby recovers the more familiar dynamical systems picture of associative memory

image segmentation based on oscillatory correlation we study image segmentation on the basis of locally excitatory globally inhibitory oscillator networks legion whereby the phases of oscillators encode the binding of pixels we introduce a lateral potential for each oscillator so that only oscillators with strong connections from their neighborhood can develop high potentials based on the concept of the lateral potential a solution to remove noisy regions in an image is proposed for legion so that it suppresses the oscillators corresponding to noisy regions but without affecting those corresponding to major regions we show that the resulting oscillator network separates an image into several major regions plus a background consisting of all noisy regions and we illustrate network properties by computer simulation the network exhibits a natural capacity in segmenting images the oscillatory dynamics leads to a computer algorithm which is applied successfully to segmenting real gray level images a number of issues regarding biological plausibility and perceptual organization are discussed we argue that legion provides a novel and effective framework for image segmentation and figure ground segregation

locally excitatory globally inhibitory oscillator networks a novel class of locally excitatory globally inhibitory oscillator networks legion is proposed and investigated the model of each oscillator corresponds to a standard relaxation oscillator with two time scales in the network an oscillator jumping up to its active phase rapidly recruits the oscillators stimulated by the same pattern while preventing other oscillators from jumping up computer simulations demonstrate that the network rapidly achieves both synchronization within blocks of oscillators that are stimulated by connected regions and desynchronization between different blocks this model lays a physical foundation for the oscillatory correlation theory of feature binding and may provide an effective computational framework for scene segmentation and figure ground segregation in real time

parallel activation of memories in an oscillatory neural network we describe a feedback neural network whose elements possess dynamic thresholds this network has an oscillatory mode that we investigate by measuring the activities of memory patterns as functions of time we observe spontaneous and induced transitions between the different oscillating memories moreover the network exhibits pattern segmentation by oscillating between different memories that are included as a mixture in a constant input the efficiency of pattern segmentation decreases strongly as the number of the input memories is increased using oscillatory inputs we observe resonance behavior

predicting the sound insulation of single leaf walls extension of cremer s model in his 1942 paper on the sound insulation of single leaf walls cremer 1942 akust z 7 81 104 made a number of approximations in order to show the general trend of sound insulation above the critical frequency cremer realized that these approximations limited the application of his theory to frequencies greater than twice the critical frequency this paper removes most of cremer s approximations so that the revised theory can be used down to the critical frequency the revised theory is used as a correction to the diffuse field limp panel mass law below the critical frequency by setting the nonexistent coincidence angle to 90 the diffuse field limp panel mass law for a finite size wall is derived without recourse to a limiting angle by following the average diffuse field single sided radiation efficiency approach the shear wave correction derived by heckl and donner 1985 rundfunktech mitt 29 287 291 is applied to the revised theory in order to cover the case of thicker walls the revised

characterizations of q p spaces in the unit ball of c n abstract let b denote the unit ball of c n for 0 p the holomorphic function spaces q p and q p 0 on the unit ball of c n are defined as f q p sup a b b f z 2 g p z a d z and f q p 0 lim a 1 b f z 2 g p z a d z 0 in this paper we give some derivative free mixture and oscillation characterizations for q p and q p 0 spaces in the unit ball of c n

a new characterization of dirichlet type spaces on the unit ball of cn abstract in this paper a bmo type characterization of dirichlet type spaces d p on the unit ball of cn is given

temporal segmentation in a neural dynamic system oscillatory attractor neural networks can perform temporal segmentation i e separate the joint inputs they receive through the formation of staggered oscillations this property which may be basic to many perceptual functions is investigated here in the context of a symmetric dynamic system the fully segmented mode is one type of limit cycle that this system can develop it can be sustained for only a limited number n of oscillators this limitation to a small number of segments is a basic phenomenon in such systems within our model we can explain it in terms of the limited range of narrow subharmonic solutions of the single nonlinear oscillator moreover this point of view allows us to understand the dominance of three leading amplitudes in solutions of partial segmentation which are obtained for high n the latter are also abundant when we replace the common input with a graded one allowing for different inputs to different oscillators switching to an input with fluctuating components we obtain segmentation dominance for small systems and quite irregular waveforms for large systems

pattern segmentation in associative memory the goal of this paper is to show how to modify associative memory such that it can discriminate several stored patterns in a composite input and represent them simultaneously segmention of patterns takes place in the temporal domain components of one pattern becoming temporally correlated with each other and anticorrelated with the components of all other patterns correlations are created naturally by the usual associative connections in our simulations temporal patterns take the form of oscillatory bursts of activity model oscillators consist of pairs of local cell populations connected appropriately transition of activity from one pattern to another is induced by delayed self inhibition or simply by noise

hopfield net generation encoding and classification of temporal trajectories hopfield network transient dynamics have been exploited for resolving both path planning and temporal pattern classification for these problems lagrangian techniques and two well known learning algorithms for recurrent networks have been used for path planning the williams and zisper s learning algorithm has been implemented and a set of temporal trajectories which join two points pass through others avoid obstacles and jointly form the shortest path possible are discovered and encoded in the weights of the net the temporal pattern classification is based on an extension of the pearlmutter s algorithm for the generation of temporal patterns which is obtained by means of variational methods the algorithm is applied to a simple problem of recognizing five temporal trajectories with satisfactory robustness to distortions

synchronization of coupled oscillations an analysis of the comparator model the authors present a model for the study of the synchronization between coupled limit cycle oscillators this model is motivated by the recent observations that revealed the existence of synchronization in the firing patterns of neural cells the study is based on a particular coupling architecture where all the oscillators are coupled to a comparator unit that feeds back to each oscillator the mean value of the total phase the various regimes of this model are analysed in the presence of non uniform external driving

modal sound transmission loss of a single leaf panel asymptotic solutions in a previously published paper c wang j acoust soc am 137 6 3514 3522 2015 the modal sound transmission coefficients of a single leaf panel were discussed with regard to the inter modal coupling effects by incorporating such effect into the equivalent modal radiation impedance which is directly related to the modal sound transmission coefficient of each mode the overall sound transmission loss for both normal and randomized sound incidences was computed through a simple modal superposition benefiting from the analytical expressions of the equivalent modal impedance and modal transmission coefficients in this paper behaviors of modal sound transmission coefficients in several typical frequency ranges are discussed in detail asymptotic solutions are also given for the panels with relatively low bending stiffnesses for which the sound transmission loss has been assumed to follow the mass law of a limp panel results are also compared to numerical analysis and the renowned mass law theories

constraints on synchronizing oscillator networks this paper investigates the constraints placed on some synchronized oscillator models by their underlying dynamics phase response graphs are used to determine the phase locking behaviors of three oscillator models these results are compared with idealized phase response graphs for single phase and multiple phase systems we find that all three oscillators studied are best suited to operate in a single phase system and that the requirements placed on oscillatory models for operation in a multiple phase system are not compatible with the underlying dynamics of oscillatory behavior for these types of oscillator models

the forced sound transmission of finite single leaf walls using a variational technique the single wall is the simplest element of concern in building acoustics but there still remain some open questions regarding the sound insulation of this simple case the two main reasons for this are the effects on the excitation and sound radiation of the wall when it has a finite size and the fact that the wave field in the wall is consisting of two types of waves namely forced waves due to the exciting acoustic field and free bending waves due to reflections in the boundary the aim of the present paper is to derive simple analytical formulas for the forced part of the airborne sound insulation of a single homogeneous wall of finite size using a variational technique based on the integral differential equation of the fluid loaded wall the so derived formulas are valid in the entire audible frequency range the results are compared with full numerical calculations measurements and alternative theory with reasonable agreement

higher radial derivative of functions of qp spaces and its applications in this paper we give some characterizations of the integral and carleson type measure both associated with higher radial derivative for holomorphic functions of q p 0 and q p spaces in the unit ball of c n as applications some sharp forms of the relations between dirichlet type spaces and q p 0 spaces are shown by means of higher radial derivative carleson type measure and constructive methods for the cases of determinism and randomization respectively

characterizations of α bloch spaces on the unit ball abstract we obtain a characterization of the bloch space for any 0 in the unit ball of c n in terms of f z f w z w moreover a new characterization for the bloch space is given

glassy synchronization in a population of coupled oscillators a phase model for a population of oscillators with random excitatory and inhibitory mean field coupling and subject to external white noise random forces is proposed and studied in the thermodynamic limit different stable phases for the oscillator population may be found i an incoherent state where all possible values of an oscillator phase are equally probable ii a synchronized state where the population has a nonzero collective phase iii a glassy phase where the global synchronization is zero but the oscillators are in phase with the random disorder and iv a mixed phase where the oscillators are partially synchronized and partially in phase with the disorder these predictions are based upon bifurcation analysis of the reduced equation valid at the thermodynamic limit and confirmed by brownian simulation

the average specific forced radiation wave impedance of a finite rectangular panel the average specific forced radiation wave impedance of a finite rectangular panel is of importance for the prediction of both sound insulation and sound absorption in 1982 thomasson published numerical calculations of the average specific forced radiation wave impedance of a square of side length 2e for wave number k in half octave steps of ke from 0 25 to 64 thomasson s calculations were for the case when the forced bending wave number kb was less than or equal to k thomasson also published approximate formulas for values of ke above and below the published results this paper combines thomasson s high and low frequency formulas and compares this combined formula with thomasson s numerical calculations the real part of the approximate formula is between 0 7 db higher and 1 db lower than the numerical calculations the imaginary part of the approximate formula is between 2 3 db higher and 2 6 db lower than the numerical calculations this paper also gives approximate formulas for the case when kb is greater than or equal to k the differences are between 0 8 and 1 2 db for the imaginary part and between 6 2 and 2 4 db for the real part

global competition and local cooperation in a network of neural oscillators abstract an architecture of locally excitatory globally inhibitory oscillator networks is proposed and investigated both analytically and by computer simulation the model for each oscillator corresponds to a standard relaxation oscillator with two time scales oscillators are locally coupled by a scheme that resembles excitatory synaptic coupling and each oscillator also inhibits other oscillators through a common inhibitor oscillators are driven to be oscillatory by external stimulation the network exhibits a mechanism of selective gating whereby an oscillator jumping up to its active phase rapidly recruits the oscillators stimulated by the same pattern while preventing the other oscillators from jumping up we show analytically that with the selective gating mechanism the network rapidly achieves both synchronization within blocks of oscillators that are stimulated by connected regions and desynchronization between different blocks computer simulations demonstrate the model s promising ability for segmenting multiple input patterns in real time this model lays a physical foundation for the oscillatory correlation theory of feature binding and may provide an effective computational framework for scene segmentation and figure ground segregation

an analytical solution for the self and mutual radiation resistances of a rectangular plate it is widely accepted that for an arbitrary acoustic wavenumber the radiation resistance of a simply supported rectangular plate has to be calculated through numerical integration in this study an analytical solution for the self and mutual radiation resistances is obtained in the form of the power series of the non dimensional acoustic wavenumber unlike the previous analytical or asymptotic solutions it is not subject to any of the restrictions usually imposed upon the acoustic wavenumber a few numerical examples are given simply to verify the solution and elucidate the reliance of the self and mutual radiation resistances on the acoustic wavenumber and the plate aspect ratio it is shown that the present formulae are extremely efficient by cutting the cpu time by orders of magnitude in comparison with the traditional numerical integration scheme this investigation successfully fills the long existing gap in solutions for the moderate wavenumbers that are often of primary concern in an acoustic analysis