a hybrid energy approach for vibrational modelling of laminated trapezoidal plates with point supports abstract an investigation on the free flexural vibration of symmetric angle ply thin trapezoidal plates continuous over arbitrarily distributed point supports is reported a hybrid energy approach which combines the pb 2 rayleigh ritz method with the lagrangian multiplier method is proposed for the modelling of the aforementioned plate problem the pb 2 rayleigh ritz method uses a set of ritz functions generated from the product of a two dimensional polynomial and the equations of boundaries each raised to the power of 0 1 or 2 corresponding to a free simply supported or clamped edge respectively the geometric boundary conditions associated with the point supports are satisfied through the use of lagrangian multipliers in this paper some new solutions for the natural frequencies of several laminated trapezoidal plates with different stacking sequences and location of point supports are presented the first known mode shapes by means of contour plots for such laminated plates are also included

three dimensional vibration analysis of cantilevered and completely free isosceles triangular plates the free vibration of cantilevered and completely free isosceles triangular plates based on exact three dimensional elasticity theory is investigated the actual plate domain is first mapped onto a basic cubic domain then the ritz method is applied to derive the eigenfrequency equation from the strain energy and the kinetic energy of the plate a set of chebyshev polynomial series multiplied by a boundary function chosen to satisfy the essential geometry boundary conditions of the plate is developed as the admissible functions of each displacement component the convergence and comparison studies show that rather accurate results can be obtained by using this approach the effects of thickness to width ratio and apex angle on eigenfrequencies of the plates are studied in detail sets of valuable results are presented which may serve as the benchmark values for future numerical techniques in thick plate vibration analysis data for the completely free isosceles triangular plates are presented for the first time

brief paper h filtering for uncertain stochastic time delay systems with sector bounded nonlinearities in this paper we deal with the robust h filtering problem for a class of uncertain nonlinear time delay stochastic systems the system under consideration contains parameter uncertainties ito type stochastic disturbances time varying delays as well as sector bounded nonlinearities we aim at designing a full order filter such that for all admissible uncertainties nonlinearities and time delays the dynamics of the filtering error is guaranteed to be robustly asymptotically stable in the mean square while achieving the prescribed h disturbance rejection attenuation level by using the lyapunov stability theory and ito s differential rule sufficient conditions are first established to ensure the existence of the desired filters which are expressed in the form of a linear matrix inequality lmi then the explicit expression of the desired filter gains is also characterized finally a numerical example is exploited to show the usefulness of the results derived

formulation of mindlin engesser model for stiffened plate vibration in this paper a mindlin engesser model is developed for the vibration analysis of moderately thick plates with arbitrarily oriented stiffeners the theoretical derivation incorporates the mindlin theory to account for the effects of transverse shear deformation and rotary inertia of plates and the engesser theory to account for the shear deformation of stiffeners with the inclusion of torsion effect in the method of solution the resulting energy functionals are minimized using the ritz procedure with a set of admissible two dimensional functions expressed in the form of simple polynomials the key kinematic feature of these shape functions is that they are boundary oriented and no boundary losses are introduced as in discretization methods with the aim of demonstrating the applicability and versatility of the method numerical examples including plates of various shapes with arbitrarily oriented stiffeners are presented several findings and conclusions regarding the method have been highlighted and discussed

the kronecker product and stochastic automata networks this paper can be thought of as a companion paper to van loan s the ubiquitous kronecker product paper j comput appl math 123 2000 85 we collect and catalog the most useful properties of the kronecker product and present them in one place we prove several new properties that we discovered in our search for a stochastic automata network preconditioner we conclude by describing one application of the kronecker product omitted from van loan s list of applications namely stochastic automata networks

stability analysis for neural networks with time varying interval delay this letter is concerned with the stability analysis of neural networks nns with time varying interval delay the relationship between the time varying delay and its lower and upper bounds is taken into account when estimating the upper bound of the derivative of lyapunov functional as a result some improved delay interval dependent stability criteria for nns with time varying interval delay are proposed numerical examples are given to demonstrate the effectiveness and the merits of the proposed method

reproducing kernel particle methods for large deformation analysis of non linear structures abstract large deformation analysis of non linear elastic and inelastic structures based on reproducing kernel particle methods rkpm is presented the method requires no explicit mesh in computation and therefore avoids mesh distortion difficulties in large deformation analysis the current formulation considers hyperelastic and elasto plastic materials since they represent path independent and path dependent material behaviors respectively in this paper a material kernel function and an rkpm material shape function are introduced for large deformation analysis the support of the rkpm material shape function covers the same set of particles during material deformation and hence no tension instability is encountered in the large deformation computation the essential boundary conditions are introduced by the use of a transformation method the transformation matrix is formed only once at the initial stage if the rkpm material shape functions are employed the appropriate integration procedures for the moment matrix and its derivative are studied from the standpoint of reproducing conditions in transient problems with an explicit time integration method the lumped mass matrices are constructed at nodal coordinate so that masses are lumped at the particles several hyperelasticity and elasto plasticity problems are studied to demonstrate the effectiveness of the method the numerical results indicated that rkpm handles large material distortion more effectively than finite elements due to its smoother shape functions and consequently provides a higher solution accuracy under large deformation unlike the conventional finite element approach the nodal spacing irregularity in rkpm does not lead to irregular mesh shape that significantly deteriorates solution accuracy no volumetric locking is observed when applying non linear rkpm to nearly incompressible hyperelasticity and perfect plasticity problems further model adaptivity in rkpm can be accomplished simply by adding more points in the highly deformed areas without remeshing

a ritz vibration analysis of doubly curved rectangular shallow shells using a refined first order theory integral expressions for strain and kinetic energies in vibration analysis of shear deformable doubly curved shallow shells are presented although the formulation follows the first order shear deformation theory the consideration of lame parameters for the transverse shear strain through shell thickness which have been hitherto neglected by other researchers shows linear distribution functions instead of constant values if the lame parameters were dropped finite higher order two dimensional orthogonal polynomials pb 2 functions previously used in thin shell analyses 3 6 have been generalized from three to five degrees to account for the additional rotation fields of a moderately thick shell these global shape functions satisfy the kinematic boundary conditions at the outset the excellent performance and versatility of the computational methodology of the pb 2 ritz method are illustrated in representative numerical simulations the resultant matrix size is far smaller than other discretization methods and yet accurate solutions can be obtained the validity of the results is verified through direct comparisons the discrepancy of various formulations with and without the lame parameters is presented and discussed

exponential stability of stochastic delay interval systems with markovian switching in the past few years a lot of research has been dedicated to the stability of interval systems as well as the stability of systems with markovian switching however little research has been on the stability of interval systems with markovian switching which is the topic of this paper the system discussed is the stochastic delay interval system with markovian switching it is a very advanced system and takes all the features of interval systems ito equations and markovian switching as well as time lag into account the theory developed is applicable in many different and complicated situations so the importance of the paper is clear

cluster synchronization stability for stochastic complex dynamical networks with probabilistic interval time varying delays the paper investigates the cluster synchronization stability problem for a class of complex dynamical networks with stochastic nonlinearities and probabilistic interval time varying delays the stochastic nonlinearities are considered here to reflect more realistic dynamical behaviors of complex networks the delay in this paper is assumed to be random and its probability distribution is known a priori based on the stochastic analysis techniques and the properties of the kronecker product delay dependent cluster synchronization stability criteria are derived in the form of linear matrix inequalities which can be readily solved by using the lmi toolbox in matlab the solvability of derived conditions depends on not only the size of the delay but also the probability of the delay taking values in some intervals finally a numerical example is given to illustrate the feasibility and effectiveness of the proposed method

effects of initial twist and thickness variation on the vibration behaviour of shallow conical shells abstract a thorough computational investigation is presented into the effects of initial twist and thickness variation on the vibratory characteristics of cantilevered pretwisted thin shallow conical shells with generally varying thickness an energy approach with the ritz minimization procedure is employed to arrive at a governing eigenvalue equation the admissiblepb 2shape functions which comprise sets of mathematically complete two dimensional orthogonal polynomials and a basic function are introduced to account for the boundary constraints and to approximate the three dimensional displacements of the conical shell the effects of angle of twist thickness variation and geometric parameters on the vibration response are presented in a comprehensive parametric study which provides useful new design data selected vibration mode shapes are also included to enhance the existing literature it is found that an increase in the angle of twist does not necessarily increase the torsional stiffness on the contrary the fundamental frequencies is reduced in the present analysis it is also observed that non zero angle of twist and non uniform chordwise thickness variation cause the absent of vibration mode symmetry

boolean dynamics of networks with scale free topology the dynamics of boolean networks with scale free topology are studied the existence of a phase transition from ordered to chaotic dynamics governed by the value of the scale free exponent of the network is shown analytically by analyzing the overlap between two distinct trajectories the phase diagram shows that the phase transition occurs for values of the scale free exponent in the open interval 2 2 5 since the boolean networks under study are directed graphs the scale free topology of the input connections and that of the output connections are studied separately ultimately these two topologies are shown to be equivalent a numerical study of the attractor structure of the configuration space reveals that this structure is similar in both networks with scale free topologies and networks with homogeneous random topologies however an important result of this work is that the fine tuning usually required to achieve stability in the dynamics of networks with homogeneous random topologies is no longer necessary when the network topology is scale free finally based on the results presented in this work it is hypothesized that the scale free topology favors the evolution and adaptation of network functioning from a biological perspective

cluster synchronization for nonlinearly time varying delayed coupling complex networks with stochastic perturbation via periodically intermittent pinning control this paper investigate the mean square exponential cluster synchronization of a class complex networks with nonlinear hybrid time varying delays and stochastic noises via periodically intermittent pinning control to be more practical the network topology can be directed and the time delay is assumed to be time varying based on the lyapunov stability theory stochastic analysis theory and linear matrix inequalities lmi the sufficient conditions are derived to guarantee the mean square exponential cluster synchronization furthermore our results can cover and extend the related ones in existing literatures some numerical simulations are provided to show the effectiveness of our theoretical results

a rayleigh ritz approach to transverse vibration of isotropic and anisotropic trapezoidal plates using orthogonal plate functions abstract to overcome the lack of a more general method for free vibration analysis of trapezoidal plates a computationally efficient and highly accurate rayleigh ritz approach with the newly developed orthogonal plate functions is proposed to solve these problems with any combination of clamped simply supported and free edge support conditions the deflection of the plate is approximated by a set of two dimensional orthogonal plate functions generated using the gram schmidt procedure which expresses the entire plate domain into two implicitly related variables in the present paper the effects of the fibre orientation on the vibrational behaviour of the plates are considered the numerical results for isotropic and anisotropic trapezoidal plates are presented where possible the numerical results are verified with other existing values in the literature

impulsive control and synchronization for delayed neural networks with reaction diffusion terms this paper discuss the global exponential stability and synchronization of the delayed reaction diffusion neural networks with dirichlet boundary conditions under the impulsive control in terms of p norm and point out the fact that there is no constant equilibrium point other than the origin for the reaction diffusion neural networks with dirichlet boundary conditions some new and useful conditions dependent on the diffusion coefficients are obtained to guarantee the global exponential stability and synchronization of the addressed neural networks under the impulsive controllers we assumed finally some numerical examples are given to demonstrate the effectiveness of the proposed control methods

elasticity solutions for free vibrations of annular plates from three dimensional analysis abstract this article examines the vibrational characteristics of annular plates by using the three dimensional elasticity theory it aims to raise the quality of the investigation beyond that provided by the two dimensional plate theories by resorting to a full three dimensional analysis a polynomials ritz model based on sets of orthogonally generated polynomial functions to approximate the spatial displacements of the plates in cylindrical polar coordinates is presented the model is then used to extract the full vibration spectrum of natural frequencies and mode shapes the vibration responses due to the variations of boundary conditions and thickness are investigated frequency parameters and three dimensional deformed mode shapes are presented in vivid graphical forms the accuracy of the method is validated through appropriate convergence and comparison studies

generation models for scale free networks abstract in the last few years it has been established that the connectivity distribution of the large real world networks often follows the power law i e they are scale free networks in this article stochastic models leading to scale free network are considered and a model close to them is proposed deterministic models for creating scale free networks with given nodes static model are demonstrated a characteristic of graphs which could be used for determining the scale free topology of networks is suggested

stability analysis of impulsive stochastic cohen grossberg neural networks with mixed time delays abstract in this paper the problem of stability analysis for a class of impulsive stochastic cohen grossberg neural networks with mixed delays is considered the mixed time delays comprise both the time varying and infinite distributed delays by employing a combination of the m matrix theory and stochastic analysis technique a sufficient condition is obtained to ensure the existence uniqueness and exponential p stability of the equilibrium point for the addressed impulsive stochastic cohen grossberg neural network with mixed delays the proposed method which does not make use of the lyapunov functional is shown to be simple yet effective for analyzing the stability of impulsive or stochastic neural networks with variable and or distributed delays we then extend our main results to the case where the parameters contain interval uncertainties moreover the exponential convergence rate index is estimated which depends on the system parameters an example is given to show the effectiveness of the obtained results

treatments of over restrained boundaries for doubly connected plates of arbitrary shape in vibration analysis abstract the problem of the free flexural vibrations of plates of doubly connected arbitrary shape is investigated a hybrid energy approach which combines both the advantages of the rayleigh ritz method and the lagrange multiplier method is developed for analysing the aforementioned plate problems the rayleigh ritz method with a set of pb 2 shape functions is used to formulate the plates with classical boundary conditions as a single continuum element while the lagrange multipliers are imposed at discrete points in the inner plate boundaries for instance when the overrestrained boundary has occurred the admissible pb 2 shape function consists of the product of a two dimensional polynomial and a basic function the basic function is defined by the product of the equations of the prescribed piecewise continuous boundary shape each raised to the power of 0 1 or 2 corresponding respectively to a free simply supported or clamped edge this set of functions automatically satisfies all the kinematic boundary conditions of the plate at the outset numerical results for several examples of doubly connected plates of arbitrary shape are presented to demonstrate the applicability and accuracy of the present method

the element free kp ritz method for free vibration analysis of conical shell panels in this paper the free vibration of conical panels is analyzed by the mesh free kp ritz method both 1 d and 2 d versions of the kp ritz approach are formulated for conical panels for conical panels with two simply supported straight edges the 1 d kp ritz version is used where the kernel particle estimation is employed in hybridized form with harmonic functions to approximate the 2 d displacement field for conical panels having arbitrary boundary conditions the displacement field is approximated by the 2 d kp ritz version with 2 d form of kernel particle functions employed the classical thin shell theory based on love s hypothesis is employed in the present analyses and based on the kernel particle concept and ritz technique the eigenequations of the frequencies of the conical panels are obtained to validate the accuracy of stability of the present method convergence studies were carried out based on the influences of the support size and the number of nodes comparisons were also made with existing results available in the open literature this study also examines in detail the effects of variation in the semi vertex angle and boundary conditions on the frequency characteristics of conical panels

flexural vibration of shear deformable circular and annular plates on ring supports this paper presents an analysis of free flexural vibration of circular and annular mindlin plates lying on multiple internal concentric ring supports the rayleigh ritz method with an admissible displacement function expressed in terms of a set of simple polynomials is used to obtain the governing eigenvalue equation the natural frequencies of circular and annular mindlin plates with one or two ring supports having inner and outer peripheries with different combinations of free simply supported and clamped conditions are determined a comprehensive set of vibration results is presented and where possible these have been verified with existing solutions published in the open literature no previous theoretical results for thick annular plates supported with internal rings are known to exist thus the study should be useful and valuable to engineers and researchers

synchronization analysis of linearly coupled networks of discrete time systems abstract in this paper we present a framework for analysis of synchronization of linearly coupled map lattices lcmls the dynamics at each node of the coupled map lattices is described by a general difference equation which can be of chaotic or others as for coupling configuration of the linearly coupled map lattices it is not assumed that the coupling matrix is symmetric and irreducible criteria are obtained for both local and global synchronization these criteria reveal that two factors influence synchronization dynamical behaviors at each node and coupling configuration by these criteria one can verify whether the lcml is synchronized which is important and useful for both understanding and interpreting synchronization phenomena and designing coupling configuration a scale d is presented to measure the synchronization capability of a linearly coupled map lattice as we show d can be regarded as a function of the smallest and the largest eigenvalues of the coupling matrix various kinds of coupling schemes including complex networks such as small world sw lattice and scale free network are studied the quantity d is carefully analyzed and calculated for each case

a stepwise resampling method of multiple hypothesis testing abstract this article introduces a method of multiple hypothesis testing that combines the idea of sequential multiple testing procedures with the structure of resampling methods the method can be seen as an alternative to the analytic method of dunnett and tamhane which requires a specific distributional form resampling incorporates the covariance structure of the data without the need for distributional assumptions recent work by westfall and young has shown that a step down resampling method is asymptotically consistent when adjusted p values can be obtained exactly for continuous data this article shows that in the case of a comparison of two groups on multiple outcomes those results are generalizable to discrete data where exact adjusted p values are not available it is shown that the method asymptotically attains the desired level for controlling the experimentwise probability of a type i error

stochastic adaptive synchronization for time varying complex delayed dynamical networks with heterogeneous nodes stochastic synchronization for a time varying complex delayed dynamical networks with heterogeneous nodes is studied in this paper using adaptive synchronization scheme for detailed analysis and discussion based on lyapunov stability theory the properties of weiner process brownian motions some controllers and adaptive laws are designed to ensure achieving stochastic synchronization of the complex delayed dynamical networks model a sufficient condition is given to ensure that the proposed controlled networks model is globally asymptotically synchronized in mean square sense a simulation example is presented to show the effectiveness and applicability of the proposed results

vibration of shallow conical shells with shear flexibility a first order theory a formulation of shear deformation theory implemented numerically for the prediction of vibratory characteristics of shallow conical shell panels is presented the derivation of thickness shear is assumed in a linear approximation the lame parameter for the transverse shear strain component which has previously been neglected is considered this consideration accounts for the replacement of a term in transverse strain distribution through the shell thickness which results in linear transverse shear strain distribution in contrast to the constant distribution hitherto known to researchers in this field the energy integral which incorporates the shear deformation and rotary inertia is minimized to derive the governing eigen matrix equation a set of benchmark frequency solutions is presented for two exemplary conical shells the cantilever and the fully clamped shells some selected mode shapes in terms of mid surface contour plots and three dimensional meshes are also illustrated

global synchronization for delayed complex networks with randomly occurring nonlinearities and multiple stochastic disturbances this paper is concerned with the synchronization problem for a new class of continuous time delayed complex networks with stochastic nonlinearities randomly occurring nonlinearities interval time varying delays unbounded distributed delays as well as multiple stochastic disturbances the stochastic nonlinearities and multiple stochastic disturbances are investigated here in order to reflect more realistic dynamical behaviors of the complex networks that are affected by the noisy environment by utilizing a new matrix functional with the idea of partitioning the lower bound 1 of the time varying delay we employ the stochastic analysis techniques and the properties of the kronecker product to establish delay dependent synchronization criteria that ensure the globally asymptotically mean square synchronization of the addressed stochastic delayed complex networks the sufficient conditions obtained are in the form of linear matrix inequalities lmis whose solutions can be readily solved by using the standard numerical software a numerical example is exploited to show the applicability of the proposed results

global asymptotic stability of stochastic recurrent neural networks with multiple discrete delays and unbounded distributed delays abstract in this paper using lyapunov krasovskii functional and the linear matrix inequality lmi approach the global asymptotic stability of stochastic recurrent neural networks with multiple discrete time varying delays and distributed delays is analyzed a new sufficient condition ensuring the global asymptotic stability for delayed recurrent neural networks is obtained in the stochastic sense using the powerful matlab lmi toolbox two examples are provided to illustrate the applicability of the stability results

parameter dependent robust stability of uncertain time delay systems this paper presents a new delay dependent and parameter dependent robust stability criterion for linear continuous time systems with polytopic parameter uncertainties and time varying delay in the state this criterion expressed as a set of linear matrix inequalities requires no matrix variable to be fixed for the entire uncertainty polytope which produces a less conservative stability test result numerical examples are given to show the effectiveness of the proposed techniques

synchronization of markovian jumping stochastic complex networks with distributed time delays and probabilistic interval discrete time varying delays the paper investigates the synchronization stability problem for a class of complex dynamical networks with markovian jumping parameters and mixed time delays the complex networks consist of m modes and the networks switch from one mode to another according to a markovian chain with known transition probability the mixed time delays are composed of discrete and distributed delays the discrete time delay is assumed to be random and its probability distribution is known a priori in terms of the probability distribution of the delays the new type of system model with probability distribution dependent parameter matrices is proposed based on the stochastic analysis techniques and the properties of the kronecker product delay dependent synchronization stability criteria in the mean square are derived in the form of linear matrix inequalities which can be readily solved by using the lmi toolbox in matlab the solvability of derived conditions depends on not only the size of the delay but also the probability of the delay taking values in some intervals finally a numerical example is given to illustrate the feasibility and effectiveness of the proposed method

distributed h state estimation for stochastic delayed 2 d systems with randomly varying nonlinearities over saturated sensor networks in this paper the distributed h state estimation problem is investigated for the two dimensional 2 d time delay systems the target plant is characterized by the generalized fornasini marchesini 2 d equations where both stochastic disturbances and randomly varying nonlinearities rvns are considered the sensor measurement outputs are subject to saturation restrictions due to the physical limitations of the sensors based on the available measurement outputs from each individual sensor and its neighboring sensors the main purpose of this paper is to design distributed state estimators such that not only the states of the target plant are estimated but also the prescribed h disturbance attenuation performance is guaranteed by defining an energy like function and utilizing the stochastic analysis as well as the inequality techniques sufficient conditions are established under which the augmented estimation error system is globally asymptotically stable in the mean square and the prescribed h performance index is satisfied furthermore the explicit expressions of the individual estimators are also derived finally numerical example is exploited to demonstrate the effectiveness of the results obtained in this paper