h filtering for fuzzy systems with immeasurable premise variables an uncertain system approach this paper discusses a design of stable filters with h disturbance attenuation of takagi sugeno fuzzy systems with immeasurable premise variables when we consider the filter design of takagi sugeno fuzzy systems the selection of premise variables plays an important role if the premise variable is the state of the system then a fuzzy system describes a wide class of nonlinear systems in this case however a filter design of fuzzy systems based on parallel distributed compensator idea is infeasible to avoid such a difficulty we consider the premise variables uncertainties then we consider a robust h filtering problem for such an uncertain system a solution of the problem is given in terms of linear matrix inequalities lmis some numerical examples are given to illustrate our theory

observer based event driven fault tolerant control for a class of system with state dependent uncertainties abstractthe method of designing an event driven observer based fault tolerant controller is addressed for a state dependent system with external disturbance and fault in this paper an event driven criterion is proposed to determine the updating of the controller based on the state of the luenberger type state dependent observer as a result communication resources can be saved significantly while the desired h performance is preserved the observer error closed loop system is rewritten as a time varying delay system by employing a state dependent integral function to be a lyapunov function candidate the error system is proved to be asymptotically stable the observer gain the controller gain and the event parameters in the event condition can be co designed and obtained in terms of solution to a set of linear matrix inequalities lmis finally a numerical example and the tunnel diode circuit model are shown that the proposed method is effective and the simulation results can reflect that the even

stability analysis for neural networks with time varying delay based on quadratic convex combination in this paper a novel method is developed for the stability problem of a class of neural networks with time varying delay new delay dependent stability criteria in terms of linear matrix inequalities for recurrent neural networks with time varying delay are derived by the newly proposed augmented simple lyapunov krasovski functional different from previous results by using the first order convex combination property our derivation applies the idea of second order convex combination and the property of quadratic convex function which is given in the form of a lemma without resorting to jensen s inequality a numerical example is provided to verify the effectiveness and superiority of the presented results

experimental investigation of the wave propagation on a point driven submerged capped cylinder using k space analysis classically sparse accelerometer measurements are made on vibrating structures to help in deducing the physics of the vibration however the experimenter now has at his command more sophisticated measurement tools such as nearfield acoustical holography or laser doppler velocimetry which provide much more data often complete mapping of the acceleration or displacements on the surface of these structures can be acquired as a result more sophisticated analysis tools must be developed such a tool useful for vibrating structures which are basically cylindrical or planar is presented herein the measured spatial velocity is decomposed at fixed temporal frequencies into its helical wave spectrum also known as the k space spectrum this decomposition contains a great deal of information about the physics of the vibrator for example it provides the dominant wavenumbers the dispersion diagram of free waves that exist on the shell these free waves reach maximum amplitudes when close to a resonance fr

surface fields on nonseparable geometries the field on the surface of a structure having nonseparable geometry may be expanded in a set of eigenfunctions suitable for that particular geometry the eigenfunctions are computed numerically using the boundary elements method to compute a matrix that relates the field on the surface of the structure to its normal derivative at vanishing frequency and diagonalizing the matrix the field on the surface of a finite cylinder with hemisphical end caps is expanded in such a set of eigenfunctions for both a simple cylinder and a cylinder containing frames results for the framed cylinder is compared to fourier decomposition of the field on the cylindrical portion of the structure

a defect relation for holomorphic curves intersecting hypersurfaces in 1933 h cartan proved a defect relation q j 1 f h j n 1 for a linearly nondegenerate holomorphic curve f inline graphic xmlns xlink http www w3 org 1999 xlink xlink href 01i and hyperplanes h j 1 j q in inline graphic xmlns xlink http www w3 org 1999 xlink xlink href 02i in general position this paper extends it to holomorphic curves intersecting hypersurfaces in 1979 b shiffman conjectured that if f inline graphic xmlns xlink http www w3 org 1999 xlink xlink href 03i is an algebraically non degenerate holomorphic map and d 1 d q are hypersurfaces in inline graphic xmlns xlink http www w3 org 1999 xlink xlink href 04i in general position then q j 1 f d j n 1 this paper proves this conjecture

data extrapolation method for boundary element method based near field acoustical holography a new data extrapolation method for boundary element method bem based near field acoustical holography nah is proposed to reduce an error of the reconstructed result obtained from the pressure measured on an aperture small compared with the structure the finiteness of the measurement aperture is a serious impediment to actual large scale implementation of nah because nah requires the measurement of the pressure field over a complete surface of structure to eliminate the requirement the wave number space data extrapolation method for fast fourier transform fft based nah has been proposed in this paper the extension of this data extrapolation method to bem based nah is presented the effectiveness of this method is demonstrated by experiments the experiment results confirm that the reconstruction error is sufficiently suppressed by the proposed method

data driven realizations of kernel and image representations and their application to fault detection and control system design this paper deals with the data driven design of observer based fault detection and control systems we first introduce the definitions of the data driven forms of kernel and image representations it is followed by the study of their identification in the context of a fault tolerant architecture the design of observer based fault detection feed forward and feedback control systems are addressed based on the data driven realization of the kernel and image representations finally the main results are demonstrated on the laboratory continuous stirred tank heater csth system

prediction of the vibroacoustic behavior of a submerged shell with non axisymmetric internal substructures by a condensed transfer function method the vibroacoustic behavior of axisymmetric stiffened shells immersed in water has been intensively studied in the past on the contrary little attention has been paid to the modeling of these shells coupled to non axisymmetric internal frames indeed breaking the axisymmetry couples the circumferential orders of the fourier series and considerably increases the computational costs in order to tackle this issue we propose a sub structuring approach called the condensed transfer function ctf method that will allow assembling a model of axisymmetric stiffened shell with models of non axisymmetric internal frames the ctf method is developed in the general case of mechanical subsystems coupled along curves a set of orthonormal functions called condensation functions which depend on the curvilinear abscissa along the coupling line is considered this set is then used as a basis for approximating and decomposing the displacements and the applied forces at the line junctions thanks to the definition and calculation of condensed transfer functions for each uncoupled subsystem and by using the superposition principle for passive linear systems the behavior of the coupled subsystems can be deduced a plane plate is considered as a test case to study the convergence of the method with respect to the type and the number of condensation functions taken into account the ctf method is then applied to couple a submerged non periodically stiffened shell described using the circumferential admittance approach caa with internal substructures described by finite element method fem the influence of non axisymmetric internal substructures can finally be studied and it is shown that it tends to increase the radiation efficiency of the shell and can modify the vibrational and acoustic energy distribution

regularization method for the application of k space data extrapolation to near field acoustical holography a regularization method for applying the k space data extrapolation method to near field acoustical holography nah is proposed the influence of the finiteness of measurement aperture is a serious impediment to the nah reconstruction of structural vibration when the size of the measurement aperture is smaller than that of the structure the k space data extrapolation method has been proposed to reduce the influence of this finiteness an appropriate regularization method is necessary to apply the k space data extrapolation method if the measured pressure is contaminated by noise some regularization methods for nah have been proposed however it is difficult to determine an appropriate k space filter if the finiteness of the measurement aperture becomes an issue an estimation method of appropriate regularization filter for applying the k space data extrapolation method is proposed to solve this difficulty the effectiveness of this method is demonstrated by simulations the simulation results confirm

addendum to on a general thue s equation the present note is an addendum to our previous article on a general thue s equation corollary 2 in that paper provides a lower bound for the values of a polynomial with algebraic coefficients at integral points our purpose here is to prove a stronger version of it also we slightly simplify its proof avoiding the use of theorem 3 in the original paper

a new fuzzy lyapunov function approach for a takagi sugeno fuzzy control system design in this paper a new fuzzy lyapunov function approach is presented for a class of continuous time takagi sugeno fuzzy control system the proposed fuzzy lyapunov function is formulated as a line integral of a fuzzy vector which is a function of the state and it can be regarded as the work done from the origin to the current state in the fuzzy vector field unlike the approaches using a fuzzy blending of multiple quadratic lyapunov functions the time derivatives of membership functions do not appear in the proposed approach the effectiveness of the proposed approach is shown through numerical examples

finite element formulation for a baffled fluid loaded finite cylindrical shell a new method for obtaining the response of a baffled fluid loaded finite cylindrical shell using the finite element method is presented the galerkin finite element formulation for this problem utilizes a neumann green s function representation of the pressure loading on the shell by representing the pressure loading in this manner only the structure need be discretized both c0 and c1 finite element discretizations of the shell are considered the finite element results are compared with the analytic solutions of the fluid loaded cylinder which are obtained using an expansion of the displacement in terms of the in vacuo modes of the naghdi cooper and flugge shell theories

a non integrated defect relation and the uniqueness theorem for meromorphic maps of a complete kahler manifold into pn c abstract in this paper a non integrated defect relation is established for meromorphic maps of an m dimensional complete kahler manifold m into p n c intersecting q hypersurfaces d 1 d q in p n c located in k subgeneral position where d 1 d q are said to be in k subgeneral position if at most k k n of these hypersurfaces meet at one point in p n c the related uniqueness theorem is also given

on a general thue s equation we analyze the integral points on varieties defined by one equation of the form f 1 f r g where the f i g are polynomials in n variables with algebraic coefficients and g has small degree we shall use a method that we recently introduced in the context of siegel s theorem for integral points on curves classical very particular instances of our equations arise e g in a well known corollary of roth s theorem the case n 2 f i linear forms deg g r 2 and with the norm form equations treated by w m schmidt here we shall prove thm 1 that the integral points are not zariski dense provided deg f i n max deg f i deg g and provided the f i g satisfy certain mild assumptions which are generically verified our conclusions also cover certain complete intersection subvarieties of our hypersurface thm 2 finally we shall prove thm 3 an analogue of the schmidt s subspace theorem for arbitrary polynomials in place of linear forms

stabilization of networked control systems with a logic zoh the technical note is concerned with the stabilization problem of networked control systems a general framework is proposed firstly where the zero order hold has the logical capability of choosing the newest control input packet the continuous time process is discretized as a system with input delays then a sufficient condition for testing the stability of the discretized system and two sufficient conditions for designing a stabilizing controller are established based upon the lyapunov theory finally numerical examples and simulations are used to illustrate the developed theory

information criteria and selection of vibration models this paper presents a method of determining an appropriate equation of motion of two dimensional plane structures like membranes and plates from vibration response measurements the local steady state vibration field is used as input for the inverse problem that approximately determines the dispersion curve of the structure this dispersion curve is then statistically treated with akaike information criterion aic which compares the experimentally measured curve to several candidate models equations of motion the model with the lowest aic value is then chosen and the utility of other models can also be assessed this method is applied to three experimental case studies a red cedar wood plate for musical instruments a thick paper subjected to unknown membrane tension and a thick composite sandwich panel these three cases give three different situations of a model selection

near field acoustic holography for an axisymmetric geometry a new formulation near field acoustic holography has recently been extended to nonseparable coordinate systems by applying the boundary elements method the formulation currently implemented applies singular value decomposition to treat the presence of evanescent waves in the near field of the structure a new method is introduced for an axisymmetric geometry that is better suited for broadband data than the singular value decomposition algorithm enabling reduced computation time and providing a new expansion for the surface field with a set of functions that can be expressed as real functions independent of frequency and independent of the choice of a measurement surface the method is tested on numerically generated data

implicit methods of solution to integral formulations in boundary element method based nearfield acoustic holography two integral equation methods are considered which can be inverted to provide the surface velocity and or pressure given a measurement of the pressure on an imaginary surface in the nearfield of a vibrating or scattering body this problem is central to nearfield acoustical holography nah the integral equations are discretized using boundary element methods bems the integral equation methods considered are 1 an indirect formulation method based on the single layer integral equation and 2 a direct formulation method based on a system of equations derived from the helmholtz kirchhoff integral equation the formation of integral equations from the mentioned methods will not involve the explicit inversion of matrices but instead will require this inversion to be done implicitly since these methods back track the sound field from the measurement surface to the surface of the source vibrator they are ill posed in nature and tikhonov regularization are used to stabilize the reconstruction problems a

subspace based adaptive method for estimating direction of arrival with luenberger observer in this paper we propose a computationally simple and efficient subspace based adaptive method for estimating directions of arrival amend for multiple coherent narrowband signals impinging on a uniform linear array ula where the previously proposed qr based method is modified for the number determination a new recursive least squares rls algorithm is proposed for null space updating and a dynamic model and the luenberger state observer are employed to solve the estimate association of directions automatically the statistical performance of the rls algorithm in stationary environment is analyzed in the mean and mean squares senses and the mean square error mse and mean square derivation msd learning curves are derived explicitly furthermore an analytical study of the rls algorithm is carried out to quantitatively compare the performance between the rls and least mean square lms algorithms in the steady state the theoretical analyses and effectiveness of the proposed rls algorithm are substantiated through numerical examples