optimal control of non homogenous prey predator models during infinite and finite time intervals we propose a lattice to describe dynamics of two animal species population one being a prey and the other a predator the problem of controlling steady states of non homogenous prey predator model during finite and infinite time intervals is studied using lyapunov bellman technique the optimal control law is derived from the conditions that ensure the asymptotic stabilization of the steady states of this model using bellman s equation the densities of both prey and predator populations are obtained as functions of time graphical and numerical example studies of the obtained results are presented

vibration analysis of annular like plates abstract the existence of eccentricity of the central hole for an annular plate results in a significant change in the natural frequencies and mode shapes of the structure in this paper the vibration analysis of annular like plates is presented based on numerical and experimental approaches using the finite element analysis code nastran the effects of the eccentricity hole size and boundary condition on vibration modes are investigated systematically through both global and local analyses the results show that analyses for perfect symmetric conditions can still roughly predict the mode shapes of recessive modes of the plate with a slightly eccentric hole they will however lead to erroneous results for dominant modes in addition the residual displacement mode shape is verified as an effective parameter for identifying damage occurring in plate like structures experimental modal analysis on a clamped free annular like plate is performed and the results obtained reveal good agreement with those obtained by numerical analysis this study provides guidance on modal analysis vibration measurement and damage detection of plate like structures

robust finite time h control of singular stochastic systems via static output feedback abstract this paper addresses the problem of robust finite time stabilization of singular stochastic systems via static output feedback firstly sufficient conditions of singular stochastic finite time boundedness on static output feedback are obtained for the family of singular stochastic systems with parametric uncertainties and time varying norm bounded disturbance then the results are extended to singular stochastic h finite time boundedness for the class of singular stochastic systems designed algorithm for static output feedback controller is provided to guarantee that the underlying closed loop singular stochastic system is singular stochastic h finite time boundedness in terms of strict linear matrix equalities with a fixed parameter finally an illustrative example is presented to show the validity of the developed methodology

finite time stabilization of linear time varying continuous systems in this technical note the problem of finite time stabilization of linear time varying continuous systems is considered necessary and sufficient conditions based upon the solution to some lyapunov differential matrix equations are proposed for particular cases of interest from these conditions the design of time varying state feedback controller guaranteeing the finite time closed loop stability is presented numerical experiments illustrate the potentialities of the approach

robust h sup spl infin filtering for uncertain markovian jump systems with mode dependent time delays this paper considers the problem of robust h sup spl infin filtering for uncertain markovian jump linear systems with time delays which are time varying and depend on the system mode the parameter uncertainties are time varying norm bounded the aim of this problem is to design a markovian jump linear filter that ensures robust exponential mean square stability of the filtering error system and a prescribed l sub 2 induced gain from the noise signals to the estimation error for all admissible uncertainties a sufficient condition for the solvability of this problem is obtained the desired filter can be constructed by solving a set of linear matrix inequalities an illustrative numerical example is provided to demonstrate the effectiveness of the proposed approach

robust h observer design of linear time delay systems with parametric uncertainty abstract this paper deals with the problem of h observer design for a class of uncertain linear systems with delayed state and parameter uncertainties this problem aims at designing the linear state observers such that for all admissible parameter uncertainties the observation process remains robustly stable and the transfer function from exogenous disturbances to error state outputs meets the prespecified h norm upper bound constraint independently of the time delay the time delay is assumed to be unknown and the parameter uncertainties are allowed to be norm bounded and appear in all the matrices of the state space model an effective matrix inequality methodology is developed to solve the proposed problem we derive the conditions for the existence of the desired robust h observers and then characterize the analytical expression of these observers in terms of some free parameters a numerical example demonstrates the validity and applicability of the present approach

observer based h control of discrete time delay systems with random communication packet losses and multiplicative noises this paper investigates the observer based h control problem for a class of discrete time mixed delay systems with random communication packet losses and multiplicative noises where the mixed delays comprise both discrete and distributed time varying delays the random packet losses are described by a bernoulli distributed white sequence that obeys a conditional probability distribution and the multiplicative disturbances are in the form of a scalar gaussian white noise with unit variance in the presence of mixed delays random packet losses and multiplicative noises sufficient conditions for the existence of an observer based feedback controller are derived such that the closed loop control system is asymptotically mean square stable and preserves a guaranteed h performance then a linear matrix inequality lmi approach for designing such an observer based h controller is presented finally a numerical example is provided to illustrate the effectiveness of the developed theoretical results

optimal h filtering for singular markovian jump systems abstract this paper considers h filtering for continuous time singular markovian jump systems smjss while the existing researches in the literature suggested only sufficient conditions in terms of strict or non strict linear matrix inequalities lmis for sub optimal h filtering this paper successfully derives a necessary and sufficient condition in terms of strict lmis for optimal h filtering first the necessary and sufficient condition that guarantees the stochastic admissibility of the filtering error system is obtained in terms of matrix inequalities to reformulate it into strict lmis the congruence transformation by specially designed matrices is used two numerical examples show the validity of proposed h filtering

generalized multidimensional orthogonal polynomials with applications to shape analysis a technique using the generalized multidimensional orthogonal polynomials gmdop for 2 d shape analysis is proposed in shape analysis spatial invariances i e translational invariance scaling invariance rotational invariance etc are important requirements for a shape analysis algorithm the described technique provides not only the three invariant properties but also mirror image rotational invariance and permutational invariance experimental results supporting the theory are presented

h control for descriptor systems a matrix inequalities approach abstract this paper considers the h control problem for descriptor systems that possibly have impulsive modes and or j axis zeros first we propose matrix inequalities that give a generalized stability condition and an h norm condition for descriptor systems using these matrix inequalities we show that the solvability of a set of matrix inequalities is necessary and sufficient to the existence of a proper controller that satisfies a prescribed h norm condition as well as stabilizing the closed loop system and eliminating all impulsive modes these inequalities are equivalent to certain linear matrix inequalities to which we can get solutions whenever they exist using efficient polynomial time algorithms

technical communique finite time stability of linear time varying systems with jumps this paper deals with the finite time stability problem for continuous time linear time varying systems with finite jumps this class of systems arises in many practical applications and includes as particular cases impulsive systems and sampled data control systems the paper provides a necessary and sufficient condition for finite time stability requiring a test on the state transition matrix of the system under consideration and a sufficient condition involving two coupled differential difference linear matrix inequalities the sufficient condition turns out to be more efficient from the computational point of view some examples illustrate the effectiveness of the proposed approach

the method of fundamental solutions applied to the calculation of eigensolutions for 2d plates in this paper we study the application of the method of fundamental solutions mfs to the numerical calculation of the eigenvalues and eigenfunctions for the 2d bilaplacian in simply connected plates this problem was considered in kang and lee j sound vib 2001 242 1 9 16 using wave type functions and in chen et al eng anal boundary elem 2004 28 535 545 using radial basis functions for circular and rectangular domains the mfs is a mesh free method that was already applied to the calculation of the eigenvalues and eigenfunctions associated with the laplace operator cf appl math lett 2001 14 7 837 842 eng anal boundary elem 2005 29 2 166 174 comput mater continua 2005 2 4 251 266 the application of this method to the bilaplace operator was already considered in chen and lee eccomas thematic conference on meshless methods lisbon 2005 for multiply connected domains but only for simple shapes here we apply an algorithm for the choice of point sources as in alves and antunes comput mater continua 2005 2 4 251 266 which leads to very good numerical results for simply connected domains a main part of this paper is devoted to the numerical analysis of the method presenting a density result that justifies the application of the mfs to the eigenvalue biharmonic equation for clamped plate problems we also present a bound for the eigenvalues approximation error equation for clamped plate problems also preser which leads to an a posteriori convergence estimate

theory of stochastic dissipative systems by introducing the escape time a new definition of the dissipativity is introduced under some assumptions that are very reasonable for most physical models based on this definition criteria on the existence and the stability of the solution are presented which can be seen as the extension of lyapunov method to the non smooth case the dissipativity is applied to cascaded nonlinear stochastic systems and interconnected systems to display the superiority of the new framework which shows that there is no need to calculate the first exit time and the escape time

small amplitude transverse vibrations of circular plates with an eccentric rectangular perforation elastically restrained against rotation and translation on both edges abstract the rayleigh ritz variational method is applied to the determination of the first four frequency coefficients for small amplitude transverse vibrations of circular plates with an eccentric rectangular perforation that is elastically restrained against rotation and translation on both edges coordinate functions are used which identically satisfy the boundary conditions at the outer circular edge while the restraining boundary conditions at the inner edge of the cutout are dealt with directly through the energetic terms in the functional expressions the procedure seems to show very good numerical stability and convergence properties as an added bonus the method allows for increased flexibility in dealing with boundary conditions at the edge of the cutout

sufficient conditions for finite time stability of impulsive dynamical systems the finite time stability problem for state dependent impulsive dynamical linear systems sd idls is addressed in this note sd idls are a special class of hybrid systems which exhibit jumps when the state trajectory reaches a resetting set a sufficient condition for finite time stability of sd idls is provided s procedure arguments are exploited to obtain a formulation of this sufficient condition which is numerically tractable by means of differential linear matrix inequalities since such a formulation may be in general more conservative a procedure which permits to automate its verification without introduce conservatism is given both for second order systems and when the resetting set is ellipsoidal

reliable finite time sliding mode control for singular time delay system with sensor faults and randomly occurring nonlinearities abstract this paper focuses on the finite time sliding mode control problem for singular time delay system with sensor failures and uncertain nonlinearities based on the proposed sliding mode control law sufficient criteria are provided to guarantee the closed loop system is singular sliding mode finite time boundedness in both reaching phase and sliding motion phase the prescribed sliding mode control law can drive the state trajectories onto the specified sliding surface in a short time interval furthermore the singular h finite time boundedness conditions for error system have been established with sensor faults over the whole interval through the linear matrix inequalities technique gain matrices for controller and estimator can be obtained finally numerical examples have been given to demonstrate the potentials of the proposed method

stochastic models for closed boundary analysis representation and reconstruction the analysis of closed boundaries of arbitrary shapes on a plane is discussed specifically the problems of representation and reconstruction are considered a one to one correspondence between the given closed boundary and a univariate or multivariate sequence of real numbers is set up univariate or multivariate circular autoregressive models are suggested for the representation of the sequence of numbers derived from the closed boundary the stochastic model representing the closed boundary is invariant to transformations like sealing translation choice of starting point and rotation over angles that are multiples of 2 pi n where n is the number of observations methods for estimating the unknown parameters of the model are given and a decision rule for choosing the appropriate number of coefficients is included constraints on the estimates are derived so that the estimates are invariant to the transformations of the boundaries the stochastic model enables the reconstruction of a dosed boundary using fft algorithms results of simulations are included and the application to contour coding is discussed

event triggered networked h control of discrete time nonlinear singular systems this paper is concerned with h controller design for a class of discrete time nonlinear singular system which is controlled over a communication network the network induced delay is considered and its distribution characteristic is described by a bernoulli stochastic variable a novel event triggered control scheme is proposed in order to save the limited network communication bandwidth based on the lyapunov kravoskii stability theory a delay distribution dependent criterion is derived which guarantees the closed loop networked discrete time nonlinear singular system is regular causal and stable with a certain h performance index a co design method for the h controller and the event triggered scheme is presented by using the singular value decomposition technology an numerical example is given to illustrate the effectiveness of the proposed method

on robust stability of singular systems with random abrupt changes this paper deals with the class of continuous time singular linear systems with markovian switching sufficient conditions on stochastic stability and robust stochastic stability are developed in the lmi setting the developed sufficient conditions are used to check if either the nominal or the uncertain systems are regular impulse free and stochastically stable or robust stochastically stable

on the lyapunov theorem for singular systems in this paper we revisit the lyapunov theory for singular systems there are basically two well known generalized lyapunov equations used to characterize stability for singular systems we start with the lyapunov theorem of the work by lewis we show that the lyapunov equation of that theorem can lead to incorrect conclusion about stability some cases where that equation can be used are clarified we also show that an attempt to correct that theorem with a generalized lyapunov equation similar to the original one leads naturally to the generalized equation of takaba et al

image normalization by complex moments the role of moments in image normalization and invariant pattern recognition is addressed the classical idea of the principal axes is analyzed and extended to a more general definition the relationship between moment based normalization moment invariants and circular harmonics is established invariance properties of moments as opposed to their recognition properties are identified using a new class of normalization procedures the application of moment based normalization in pattern recognition is demonstrated by experiment

robust stability and stabilization of uncertain discrete time markovian jump linear systems this note deals with robust stability and control of uncertain discrete time linear systems with markovian jumping parameters systems with polytopic type parameter uncertainty in either the state space model matrices or in the transition probability matrix of the markov process are considered this note develops methods of robust stability analysis and robust stabilization in the mean square sense which are dependent on the system uncertainty the design of both mode dependent and mode independent control laws is addressed the proposed methods are given in terms of linear matrix inequalities numerical examples are provided to demonstrate the effectiveness of the derived results

finite time stability and stabilization of nonlinear stochastic hybrid systems this paper deals with the problem of finite time stability and stabilization of nonlinear markovian switching stochastic systems which exist impulses at the switching instants using multiple lyapunov function theory a sufficient condition is established for finite time stability of the underlying systems furthermore based on the state partition of continuous parts of systems a feedback controller is designed such that the corresponding impulsive stochastic closed loop systems are finite time stochastically stable a numerical example is presented to illustrate the effectiveness of the proposed method

technical communique new bounded real lemma for discrete time singular systems in this paper the problem of bounded real lemma for discrete time singular system with strict matrix inequalities is investigated it is proved that the bounded real lemma for discrete singular system can be described by a strict matrix inequality the results lead to more tractable and reliable computation when applying them to design control systems

finite time h control for t s fuzzy descriptor semi markov jump systems via static output feedback abstract this paper is concerned with the finite time static output feedback h controller design problem for a type of nonlinear continuous time descriptor semi markov jump systems s mjss via takagi sugeno t s fuzzy model where the transition rates are time varying and dependent on sojourn time firstly based on the stochastic lyapunov functional sufficient conditions on singular stochastic h finite time boundedness ss h ftb for continuous time t s fuzzy descriptor s mjss are given then in order to design the static output feedback controller easily the closed loop system is represented in an augmented form furthermore based on the lower and upper bounds of the time varying transition rates and by using the matrix inequality decoupling technique a novel linear matrix inequality lmi condition on ss h ftb of closed loop system is presented meanwhile the static output feedback controller is developed in terms of lmis the proposed design method doesn t impose any constraints on system matrices or slack variables which shows less conservative results lastly numerical examples are given to demonstrate the effectiveness of the obtained methods

recognitive aspects of moment invariants moment invariants are evaluated as a feature space for pattern recognition in terms of discrimination power and noise tolerance the notion of complex moments is introduced as a simple and straightforward way to derive moment invariants through this relation properties of complex moments are used to characterize moment invariants aspects of information loss suppression and redundancy encountered in moment invariants are investigated and significant results are derived the behavior of moment invariants in the presence of additive noise is also described

small amplitude transverse vibrations of circular plates elastically restrained against rotation with an eccentric circular perforation with a free edge abstract rayleigh ritz variational method is applied to the determination of the first four frequency coefficients for the title problem by making use of coordinate functions which identically satisfy the boundary conditions at the outer edge good stability and convergence properties are found the mathematical model seems to be realistic and accurate within the realm of the classical theory of vibrating plates

h filtering for a class of uncertain nonlinear systems abstract this paper investigates the problem of h filtering for a class of uncertain continuous time nonlinear systems with real time varying parameter uncertainty and unknown initial state we develop an infinite horizon h filtering methodology which provides both robust stability and a guaranteed h performance for the filtering error irrespective of the parameter uncertainty

method for solving eigenvalue problems of the helmholtz equation with an arbitrarily shaped outer boundary and a number of eccentric inner boundaries of arbitrary shape this paper presents a method for solving eigenvalue problems of various phenomena that are governed by the helmholtz equation with an arbitrarily shaped outer boundary and a number of eccentric boundaries of arbitrary shape in the analysis the outer boundary condition is satisfied by means of the fourier expansion collocation method using the exact solution of the equation of motion to satisfy the inner boundary conditions the point restraints are added to the equation of motion and the inner boundary conditions are satisfied by making use of a point matching procedure the equation for finding the eigenvalues are derived and numerical calculations are carried out for cases of elliptical outer and inner boundaries and polygonal outer and inner boundaries

technical communique finite time control of linear systems subject to parametric uncertainties and disturbances in this paper we consider finite time control problems for linear systems subject to time varying parametric uncertainties and to exogenous constant disturbances the main result provided is a sufficient condition for robust finite time stabilization via state feedback it can be applied to problems with both non zero initial conditions and unknown constant disturbances this condition is then reduced to a feasibility problem involving linear matrix inequalities lmis a detailed example is presented to illustrate the proposed methodology

technical communique h state feedback control for generalized continuous discrete time delay system in this paper we consider the problem of designing h state feedback controller for the generalized time delay systems with delayed states and control inputs in continuous and discrete time cases respectively the generalized time delay system problems are solved on the basis of linear matrix inequality lmi technique considering time delays the sufficient condition for the existence of controller and h state feedback controller design methods are presented also using some changes of variables and schur complements the obtained sufficient condition can be rewritten as an lmi form in terms of transformed variables the proposed controller design method can be extended into the problem of robust h state feedback controller design method easily

control of markovian jump discrete time systems with norm bounded uncertainty and unknown delay this paper studies the problem of control for discrete time delay linear systems with markovian jump parameters the system under consideration is subjected to both time varying norm bounded parameter uncertainty and unknown time delay in the state and markovian jump parameters in all system matrices we address the problem of robust state feedback control in which both robust stochastic stability and a prescribed h sub spl infin performance are required to be achieved irrespective of the uncertainty and time delay it is shown that the above problem can be solved if a set of coupled linear matrix inequalities has a solution

transverse vibrations of a circular plate with a concentric square hole with free edges the present study deals with the determination of the lower natural frequencies of vibration

state estimation and sliding mode control of markovian jump singular systems this paper is concerned with the state estimation and sliding mode control problems for continuous time markovian jump singular systems with unmeasured states firstly a new necessary and sufficient condition is proposed in terms of strict linear matrix inequality lmi which guarantees the stochastic admissibility of the unforced markovian jump singular system then the sliding mode control problem is considered by designing an integral sliding surface function an observer is designed to estimate the system states and a sliding mode control scheme is synthesized for the reaching motion based on the state estimates it is shown that the sliding mode in the estimation space can be attained in a finite time some conditions for the stochastic admissibility of the overall closed loop system are derived finally a numerical example is provided to illustrate the effectiveness of the proposed theory

stochastic stability properties of jump linear systems jump linear systems are defined as a family of linear systems with randomly jumping parameters usually governed by a markov jump process and are used to model systems subject to failures or changes in structure the authors study stochastic stability properties in jump linear systems and the relationship among various moment and sample path stability properties it is shown that all second moment stability properties are equivalent and are sufficient for almost sure sample path stability and a testable necessary and sufficient condition for second moment stability is derived the lyapunov exponent method for the study of almost sure sample stability is discussed and a theorem which characterizes the lyapunov exponents of jump linear systems is presented finally for one dimensional jump linear system it is proved that the region for delta moment stability is monotonically converging to the region for almost sure stability at delta down arrow 0 sup

robust h spl infin filter design for uncertain linear systems with multiple time varying state delays the problem of robust h spl infin filtering for continuous time uncertain linear systems with multiple time varying delays in the state variables is investigated the uncertain parameters are supposed to belong to a given convex bounded polyhedral domain the aim is to design a stable linear filter assuring asymptotic stability and a prescribed h spl infin performance level for the filtering error system irrespective of the uncertainties and the time delays sufficient conditions for the existence of such a filter are established in terms of linear matrix inequalities which can be efficiently solved by means of powerful convex programming tools with global convergence assured an example illustrates the proposed methodology

optimal control of an angular motion of a rigid body during infinite and finite time intervals this paper discusses the problem of optimal control of uniform angular motion of a rigid body containing an ideal fluid during both finite and infinite time intervals is studied by using lyapunov bellman technique using bellman equation the optimal control moments ensuring asymptotic stability of desired motion in both cases are obtained as non linear functions of the phase coordinates and time we are not concerned with the attitude of the body and consider only the evolution of the angular velocity as described by euler s equations the square of the euclidean norm of the perturbation of the angular velocity in both cases is estimated as a transcendental function of time

on designing of sliding mode control for stochastic jump systems in this note we consider the problems of stochastic stability and sliding mode control for a class of linear continuous time systems with stochastic jumps in which the jumping parameters are modeled as a continuous time discrete state homogeneous markov process with right continuous trajectories taking values in a finite set by using linear matrix inequalities lmis approach sufficient conditions are proposed to guarantee the stochastic stability of the underlying system then a reaching motion controller is designed such that the resulting closed loop system can be driven onto the desired sliding surface in a limited time it has been shown that the sliding mode control problem for the markovian jump systems is solvable if a set of coupled lmis have solutions a numerical example is given to show the potential of the proposed techniques

robust h sub spl infin control of discrete time markovian jump linear systems with mode dependent time delays considers the class of discrete time markovian jump linear system with norm bounded uncertainties and time delay which is dependent on the system mode linear matrix inequality lmi based sufficient conditions for the stability stabilization and h sub spl infin control are developed a numerical example is worked out to show the usefulness of the theoretical results

finite time h static output control of markov jump systems with an auxiliary approach this paper considers the finite time h static output feedback control of markov jump systems with the help of introducing two new variables related to the original system state and output sufficient conditions for the closed loop system to be stochastic finite time boundedness with the prescribed h performance level are proposed in terms of linear matrix inequalities lmis meanwhile the static output control gains are solved explicitly by the proposed conditions it is shown that the proposed method is less or at least the same conservative than the existing result lastly a numerical example is given to demonstrate the effectiveness of the proposed method

an implicit sequential algorithm for solving coupled lyapunov equations of continuous time markovian jump systems in this paper an implicit sequential algorithm is presented for solving coupled lyapunov matrix equations of continuous time markovian jump linear systems first some existing iterative algorithms which can be utilized to solve the coupled lyapunov matrix equations are reviewed and discussed next based on the existing parallel iterative algorithm an implicit sequential algorithm is proposed by using the latest updated information the proposed algorithm fills the current gap of implicit algorithms for solving continuous coupled lyapunov matrix equations it is shown that the proposed algorithm with zero initial conditions can monotonically converge to the unique positive definite solutions of the coupled lyapunov matrix equations if the associated markovian jump system is stochastically stable moreover a necessary and sufficient condition is established for the proposed algorithm to be convergent the algorithm presented in this paper has much better convergence performance than other existing iterative algorithms and requires less storage capacity finally a numerical example is given to show the effectiveness of the proposed algorithm

classification of partial 2 d shapes using fourier descriptors we present a method for the classification of 2 d partial shapes using fourier descriptors we formulate the problem as one of estimating the fourier descriptors of the unknown complete shape from the observations derived from an arbitrarily rotated and scaled shape with missing segments the method used for obtaining the estimates of the fourier descriptors minimizes a sum of two terms the first term of which is a least square fit to the given data subject to the condition that the number of missing boundary points is not known and the second term is the perimeter2 area of the unknown shape experiments with synthetic and real boundaries show that estimates closer to the true values of fourier descriptors of complete boundaries are obtained also classification experiments performed using real boundaries indicate that reasonable classification accuracies are obtained even when 20 30 percent of the data is missing

method for solving eigenvalue problems of the helmholtz equation with a circular outer and a number of eccentric circular inner boundaries the eigenvalue problem of the helmholtz equation is of importance because various physical phenomena are governed by this equation this article presents a method for solving the boundary value problem governed by the helmholtz equation with a circular outer boundary and a number of eccentric circular inner boundaries in this problem it is difficult to satisfy the multiconnected boundary conditions the present analysis uses the point matching approach for treating the inner boundary conditions and presents the expression for finding the eigenvalues numerical calculations have been carried out for the system having one two or four eccentric circular inner boundaries

robust finite time stability and stabilization of uncertain markovian jump systems with time varying delay this paper deals with the robust finite time stability and stabilization problems of uncertain stochastic delayed jump systems where the uncertainty is in the form of additive perturbations and exists in the drift and diffusion sections simultaneously though perturbation time varying delay and brownian motion existing at the same time two conditions checking its robust finite time stability are proposed by a mode dependent parameter approach which are different from some existing methods based on the proposed results sufficient conditions for the existence of the state feedback controller are provided with lmis which could be solved directly it is seen that all the features of the underlying system such as time varying delay perturbation diffusion mode dependent parameters and uncertain transition rate matrix play important roles in the system analysis and synthesis of finite time stability finally numerical examples are used to demonstrate the effectiveness and superiority of the proposed methods

mathematical analysis and numerical study to free vibrations of annular plates using biem and bem in this paper the spurious eigenequations for annular plate eigenproblems by using biem and bem are studied in the continuous and discrete systems since any two boundary integral equations in the plate formulation 4 equations can be chosen 6 c options can be considered instead of only two approaches single layer and double layer methods or singular and hypersingular equations which are adopted for the eigenproblems of the membrane and acoustic problems the occurring mechanism of the spurious eigenequation for annular plates in the complex valued formulations is studied analytically for the continuous system degenerate kernels for the fundamental solution and the fourier series expansion for the circular boundary density are employed to derive the true and spurious eigenequations analytically for the discrete system the degenerate kernels for the fundamental solution and circulants resulting from the circular boundary are employed to determine the true and spurious eigenequations true eigenequation depends on the specified boundary condition while spurious eigenequation is embedded in each formulation it is found that the spurious eigenvalue for the annular plate is the true eigenvalue of the associated interior problem with an inner radius of the annular domain also we provide three methods svd updating technique burton and miller method and chief method to suppress the occurrence of the spurious eigenvalues several examples were demonstrated to check the validity of the formulations copyright 2005 john wiley sons ltd

free vibration analysis of circular plates with multiple circular holes using indirect biems in this paper a semi analytical approach is proposed to solve natural frequencies and natural modes for circular plates with multiple circular holes by using the indirect formulation in conjunction with degenerate kernels and fourier series all the kernels in the indirect formulation are expanded into degenerate form by uniformly collocating points on the boundary a linear algebraic system can be constructed the direct searching approach is adopted to determine the natural frequency through singular value decomposition svd after determining the unknown fourier coefficients the corresponding mode shape is obtained by using the indirect boundary integral formulations the results of the annular plate as a special case are compared with the analytical solution to verify the validity of the present method for the cases of circular plates with multiple circular holes the results are also compared with those of finite element method fem using abaqus besides the effect of eccentricity of the hole on the natural frequencies is also considered good accuracy high rate of convergence and computational efficiency are the main features of the present method due to the semianalytical procedure r 2007 elsevier ltd all rights reserved

trilateral teleoperation of adaptive fuzzy force motion control for nonlinear teleoperators with communication random delays in this paper an adaptive fuzzy control scheme is proposed for hybrid motion force of trilateral teleoperation systems with a dual master single slave configuration under stochastic time varying delays in communication channels different from previous works on bilateral teleoperation systems this paper addresses dual master trilateral control of a single holonomic constrained robotic manipulator where the communication delays are modeled as multiple markov chains and the motion force controls are investigated under consideration of unsymmetric stochastic time varying delays and system dynamical uncertainties using partial feedback linearization the whole trilateral teleoperation system which consists of both master and slave manipulator dynamics is transformed into three subsystems by integrating markov jump systems to handle random delays adaptive fuzzy control strategies are developed for the nonlinear teleoperators with modeling uncertainties and external disturbances by using the approximation property of the fuzzy logic systems flss it is proven that the trilateral teleoperation system is stochastically stable in mean square under specific linear matrix inequality lmi conditions and all the signals of the resulting closed loop system are uniformly bounded the proposed scheme is validated by extensive simulations

mean square admissibility for stochastic ts fuzzy singular systems based on extended quadratic lyapunov function approach the mean square admissibility problem of stochastic ts fuzzy singular systems via an extended quadratic lyapunov function is investigated in this paper comparing with the existing quadratic lyapunov function method the extended quadratic lyapunov function method can relax stabilization conditions firstly the sufficient condition is given for the mean square admissibility of stochastic ts fuzzy singular systems based on an extended quadratic lyapunov function approach secondly two sufficient conditions for mean square admissibility of closed loop systems via the parallel distributed compensation pdc fuzzy controller and non parallel distributed compensation non pdc fuzzy controller are proposed furthermore through the extended quadratic lyapunov function method and non pdc fuzzy controller the less conservative mean square admissibility conditions on solving fuzzy controllers are derived in terms of linear matrix inequalities lmis finally some simulation examples are given to show the effectiveness and merits of the proposed fuzzy controller design methodology

stabilization of hybrid neutral stochastic differential delay equations by delay feedback control abstract this paper is concerned with the problem of exponential mean square stabilization of hybrid neutral stochastic differential delay equations with markovian switching by delay feedback control a delay feedback controller is designed in the drift part so that the controlled system is mean square exponentially stable we discussed two types of structure controls that is state feedback and output injection the stabilization criteria are derived in terms of linear matrix inequalities

filtering and smoothing in an h sup infinity setting the problems of filtering and smoothing are considered for linear systems in an h sup infinity setting i e the plant and measurement noises have bounded energies are in l sub 2 but are otherwise arbitrary two distinct situations for the initial condition of the system are considered the initial condition is assumed known in one case while in the other the initial condition is not known but the initial condition the plant and measurement noise are in some weighted ball of r sup n xl sub 2 finite horizon and infinite horizon cases are considered necessary and sufficient conditions are presented for the existence of estimators both filters and smoothers that achieve a prescribed performance bound and algorithms that result in performance within the bounds are developed in case of smoothers the optimal smoother is also presented the approach uses basic quadratic optimization theory in a time domain setting as a consequence of which both linear time varying and time invariant systems can be considered with equal ease in the smoothing problem for linear time varying systems one considers only the finite horizon case

brief paper stability and stabilization of continuous time singular hybrid systems in this paper the problems of stability and state feedback stabilization for a class of continuous time singular hybrid systems are investigated a new sufficient and necessary condition for a continuous time singular hybrid system to be regular impulse free and stochastically stable is proposed in terms of a set of coupled strict linear matrix inequalities lmis moreover a new sufficient and necessary condition is presented for the existence of the state feedback controller in terms of a set of coupled strict matrix inequalities finally a numerical example is given to illustrate the effectiveness of the obtained theoretical results

brief paper finite time control of discrete time linear systems analysis and design conditions in this paper we deal with some finite time control problems for discrete time time varying linear systems first we provide necessary and sufficient conditions for finite time stability these conditions require either the computation of the state transition matrix of the system or the solution of a certain difference lyapunov inequality then we address the design problem the proposed conditions allow us to find output feedback controllers which stabilize the closed loop system in the finite time sense all these conditions can be expressed in terms of lmis and therefore are numerically tractable as shown in the example included in the paper

robust finite time h control for uncertain discrete jump systems with time delay abstract this paper addresses the robust finite time h control problem for a family of uncertain discrete time markovian jump systems with time delay initially the concepts of stochastic finite time boundedness and stochastic h finite time stabilization are given then a stochastic finite time h controller is designed such that the underlying closed loop discrete jump time delay system is stochastic finite time boundedness and satisfies a prescribed h performance level in some given finite time interval based on lyapunov approach sufficient criteria on the stochastic h finite time stabilization are established for the solvability of the problem which can be handled by a feasibility problem in the form of linear matrix inequalities with a fixed parameter finally simulation examples are presented to demonstrate the validity of the developed techniques

robust finite time h control for discrete time singular markovian jump systems with time varying delay and actuator saturation in this paper the problem of robust finite time h control for discrete time singular markovian jump systems with time varying delay and actuator saturation is studied first sufficient conditions that guarantee the systems singular stochastic finite time boundedness are derived via constructing a delay dependent lyapunov krasonskii functional and linear matrix inequalities lmi approaches then the results are extended to singular stochastic finite time h boundedness furthermore with these conditions and convex optimization arithmetic the design method of h controller and conditions that ensure the h disturbance attenuation level are obtained finally some numerical examples are presented to illustrate the validity and efficiency of the proposed methods

on image analysis by the methods of moments various types of moments have been used to recognize image patterns in a number of applications a number of moments are evaluated and some fundamental questions are addressed such as image representation ability noise sensitivity and information redundancy moments considered include regular moments legendre moments zernike moments pseudo zernike moments rotational moments and complex moments properties of these moments are examined in detail and the interrelationships among them are discussed both theoretical and experimental results are presented

dynamic output feedback control for singular markovian jump system lmi approach for the dynamic output feedback stabilization of continuous time singular markovian jump systems this paper introduces the necessary and sufficient condition whereas the previous research works suggested the sufficient conditions a special choice of the block entries of lyapunov matrices leads to derive the necessary and sufficient condition in terms of linear matrix inequalities a numerical example shows the validity of the derived results

robust sliding mode control for markovian jump singular systems with randomly changing structure abstract this paper discusses the robust optimization by a sliding mode control smc approach for uncertain singular markovian jump smj time varying delay system with nonlinear perturbation which uncertainties occur randomly firstly a different integral type sliding mode surface sms and a different lyapunov krasovskii function are introduced secondly by using linear matrix inequalities sufficient conditions are proposed to ensure the mean square exponentially admissible msea with an h performance level of the unforced uncertain smj time varying delay system in the specified sms next a composed smc law with the parameter uncertainties occurring randomly can ensure the reachability of the predefined sms finally three numerical examples are given to test the feasibility of the theory

finite time h control for a class of discrete time switched singular time delay systems subject to actuator saturation this paper concerns with the finite time h control problem for a class of discrete time switched singular time delay with actuator saturation not only linear matrix inequality conditions for the systems but also average dwell time of switching signal is given to guarantee regular causal and finite time boundedness for the discrete time switched singular time delay system moreover sufficient conditions are presented to ensure the h disturbance attenuation level and the design method of h controller is developed by solving linear matrix inequalities lmi optimization problem without any decompositions of system matrices and equivalent transformation furthermore the function in the proof procedure belongs to multiple lyapunov like functions whose advantage lies in their flexibility finally numerical examples are employed to verify the effectiveness of the proposed methods and to illustrate the significant improvement on the conservativeness of some reported results in the literature

partially mode dependent design of h filter for stochastic markovian jump systems with mode dependent time delays abstract this paper is concerned with the h filtering problem for stochastic delay systems with markovian jump parameters where both the state dynamics and measurements of systems are corrupted by wiener process in contrast with traditional mode dependent and mode independent filtering methods a new partially mode dependent filter is established via using a mode dependent lyapunov function where the system mode available to filter implementation is transmitted through an unreliable network and the stochastic property of mode available to a filter is considered sufficient conditions for the existence of h filters are obtained as linear matrix inequalities finally an example is used to show the effectiveness of the given theoretical results

stabilization of stochastic singular nonlinear hybrid systems abstract this paper deals with the control of the class of singular nonlinear stochastic hybrid systems under some appropriate assumptions results on stochastic stability and stochastic stabilization are developed two state feedback controllers linear and nonlinear that stochastically stabilize the class of systems we are considering are designed lmi sufficient conditions are developed to compute the gains of these controllers

the extended kalman filter as an exponential observer for nonlinear systems we analyze the behavior of the extended kalman filter as a state estimator for nonlinear deterministic systems using the direct method of lyapunov we prove that under certain conditions the extended kalman filter is an exponential observer i e the dynamics of the estimation error is exponentially stable furthermore we discuss a generalization of the kalman filter with exponential data weighting to nonlinear systems

adaptive stabilization of stochastic nonholonomic systems with nonlinear parameterization this paper investigates the problem of adaptive stabilization by state feedback for a class of stochastic nonholonomic systems in chained form with nonlinear parameterization a parameter separation technique is introduced to transform the nonlinear parameterized nonholonomic system into a linear like parameterized one then using input state scaling and backstepping techniques an adaptive state feedback controller is obtained based on switching strategy to eliminate the phenomenon of uncontrollability global asymptotic regulation in probability of the closed loop system states are guaranteed finally a simulation example is provided to illustrate the effectiveness of the proposed method

robust h infinity filtering for a class of non linear systems with state delay and parameter uncertainty this paper deals with the problem of robust h infinity filtering for a class of state delayed non linear systems with normbounded parameter uncertainty appearing in all the matrices of the linear part of the system model the non linearities are assumed to satisfy the global lipschitz conditions and appear in both the state and measured output equations attention is focused on the design of a non linear filter which ensures both the robust stability and a prescribed h infinity performance of the filtering error dynamics for all admissible uncertainties a sufficient condition for the existence of such a filter is given in terms of a linear matrix inequality lmi when this lmi is feasible the expression of a desired h infinity filter is also presented a numerical example is provided to demonstrate the applicability of the proposed approach

robust h sub spl infin control of uncertain markovian jump systems with time delay this paper is concerned with the robust stochastic stabilizability and robust h sub spl infin disturbance attenuation for a class of uncertain linear systems with time delay and randomly jumping parameters the transition of the jumping parameters is governed by a finite state markov process sufficient conditions on the existence of a robust stochastic stabilizing and spl gamma suboptimal h sub spl infin state feedback controller are presented using the lyapunov functional approach it is shown that a robust stochastically stabilizing h sub spl infin state feedback controller can be constructed through the numerical solution of a set of coupled linear matrix inequalities

an efficient approach for the assembly of mass and stiffness matrices of structures with modifications the finite element method is one of the most common tools for the comprehensive analysis of structures with applications reaching from static often nonlinear stress strain to transient dynamic analyses for single calculations the expense to generate an appropriate mesh is often insignificant compared to the analysis time even for complex geometries and therefore negligible however this is not the case for certain other applications most notably structural optimization procedures where the re meshing effort is very important with respect to the total runtime of the procedure thus it is desirable to find methods to efficiently generate mass and stiffness matrices allowing to reduce this effort especially for structures with modifications of minor complexity e g panels with cutouts therefore a modeling approach referred to as energy modification method is proposed in this paper the underlying idea is to model and discretize the basis structure e g a plate and the modifications e g holes separately the discretized energy expressions of the modifications are then subtracted from or added to the energy expressions of the basis structure and the coordinates are related to each other by kinematical constraints leading to the mass and stiffness matrices of the complete structure this approach will be demonstrated by two simple examples a rod with varying material properties and a rectangular plate with a rectangular or circular hole using a finite element discretization as basis convergence studies of the method based on the latter example follow demonstrating the rapid convergence and efficiency of the method finally the energy modification method is successfully used in the structural optimization of a circular plate with holes with the objective to split all its double eigenfrequencies