modified quadratic discriminant functions and the application to chinese character recognition issues in the quadratic discriminant functions qdf are discussed and two types of modified quadratic disriminant functions mqdf1 mqdf2 which are less sensitive to the estimation error of the covariance matrices are proposed the mqdf1 is a function which employs a kind of a pseudo bayesian estimate of the covariance matrix instead of the maximum likelihood estimate ordinarily used in the qdf the mqdf2 is a variation of the mqdf1 to save the required computation time and storage two discriminant functions were applied to chinese character recognition to evaluate their effectiveness and remarkable improvement was observed in their performance

periodic solution for a delay multispecies logarithmic population model with feedback control in this paper a delay multispecies logarithmic population model with feedback control is studied by using the contraction mapping principle as well as a new transformation some new results on the existence and uniqueness of the periodic solution are obtained after that by constructing a suitable lyapunov functional a set of easily applicable criteria is established for the global asymptotically stability of the periodic solution

periodicity in a delayed ratio dependent predator prey system abstract with the help of a continuation theorem based on gaines and mawhin s coincidence degree easily verifiable criteria are established for the global existence of positive periodic solutions of a delayed ratio dependent predator prey system in a periodic environment

on the periodic solutions of periodic multi species kolmogorov type competitive system with delays and feedback controls abstract in this paper we consider a periodic multi species kolmogorov type competitive system with delays and feedback controls applying schauder s fixed point theorem a criterion on the existence of the positive periodic solution of the system are obtained as application the existence of the positive periodic solution of a kind of nonlinear competitive model with delays and feedback controls is discussed

galerkin s method for ordinary differential equations subject to generalized nonlinear boundary conditions where xk belongs to tc a finite dimensional subspace of cc l 11 r il ii and i qj is a projection mapping cc l 11 r i i x r onto a subspace of c 1 11 r 11 ii having the same dimension as rck there is a vast collection of literature concerning the application of galerkin s method to differential equations 1 3 12 16231 we make a special reference to the papers of cesari 4 5 and urabe 22 23 our results provide an extension and a unification of previous results of urabe that were conderned with the determination of periodic solutions to systems of ordinary differential equations 22 and with the solvability of 112 0022 0396192 3 00

periodicity and stability for a lotka volterra type competition system with feedback controls and deviating arguments abstract this paper deals with the general periodic lotka volterra type competition systems with feedback controls and deviating arguments by employing fixed point index theory on cone an explicit necessary and sufficient condition for the global existence of the positive periodic solution of the systems is proved by constructing a suitable lyapunov functional a set of easily verifiable sufficient conditions for the global asymptotic stability of the positive periodic solution of the systems is given

multiple positive periodic solutions for a class of state dependent delay functional differential equations with feedback control by employing krasnoselskii fixed point theorem we investigate the existence of multiple positive periodic solutions for a class of state dependent delay functional differential equations with feedback control the system considered in this paper is more general and incorporates as special cases various problems which have been studied extensively in the literature moreover some easily verifiable sufficient criteria are established

coupled fixed points of multivalued operators and first order odes with state dependent deviating arguments abstract we establish a coupled fixed point theorem for a meaningful class of mixed monotone multivalued operators and then we use it to derive some results on the existence of quasisolutions and unique solutions to first order functional differential equations with state dependent deviating arguments our results are very general and can be applied to functional equations featuring discontinuities with respect to all of their arguments but we emphasize that they are new even for differential equations with continuously state dependent delays

existence and multiplicity of positive periodic solutions for a class of higher dimension functional differential equations with impulses this paper deals with the existence of multiple periodic solutions for n dimensional functional differential equations with impulses by employing the krasnoselskii fixed point theorem we obtain some easily verifiable sufficient criteria which extend previous results

on state dependent delay partial neutral functional integro differential equations in this paper the existence of mild solutions for a class of abstract neutral integro differential equations with state dependent delay is studied

positive periodic solutions of a class of delay differential system with feedback control with the help of continuation theorem based on gaines and mawhin s coincidence degree sufficient and realistic conditions are obtained for the global existence of positive periodic solutions for the delay differential system with feedback control when these results are applied to some special delay population models some new results are obtained and some known results are generalized

eigen deformations for elastic matching based handwritten character recognition deformations in handwritten characters have category dependent tendencies in this paper the estimation and the utilization of such tendencies called eigen deformations are investigated for the better performance of elastic matching based handwritten character recognition the eigen deformations are estimated by the principal component analysis of actual deformations automatically collected by the elastic matching from experimental results it was shown that typical deformations of each category can be extracted as the eigen deformations it was also shown that the recognition performance can be improved significantly by using the eigen deformations for the detection of overfitting which is the main cause of the misrecognition in the elastic matching based recognition methods

representation and recognition of handwritten digits using deformable templates we investigate the application of deformable templates to recognition of handprinted digits two characters are matched by deforming the contour of one to fit the edge strengths of the other and a dissimilarity measure is derived from the amount of deformation needed the goodness of fit of the edges and the interior overlap between the deformed shapes classification using the minimum dissimilarity results in recognition rates up to 99 25 percent on a 2 000 character subset of nist special database 1 additional experiments on an independent test data were done to demonstrate the robustness of this method multidimensional scaling is also applied to the 2 000 spl times 2 000 proximity matrix using the dissimilarity measure as a distance to embed the patterns as points in low dimensional spaces a nearest neighbor classifier is applied to the resulting pattern matrices the classification accuracies obtained in the derived feature space demonstrate that there does exist a good low dimensional representation space methods to reduce the computational requirements the primary limiting factor of this method are discussed

shape matching using lat and its application to handwritten numeral recognition this paper describes an iterative technique for gradually deforming a mask binary image with successive local affine transformation lat operations so as to yield the best match to an input binary image as one new and promising approach toward robust handwritten character recognition the method uses local shapes in the sense that the lat of each point at one location is optimized using locations of other points by means of least squares data fitting using gaussian window functions it also uses a multiscale refinement technique that decreases the spread of window functions with each iteration especially in handwritten character recognition structural information is indispensable for robust shape matching or discrimination the method is enhanced to explicitly incorporate structures by weighting the above least squares criterion with similarity measures of both topological and geometric features of the mask and input images moreover deformation constraints are imposed on each iteration not only to promote and stabilize matching convergence but also to suppress an excessive matching process shape matching experiments have been successfully carried out using skeletons of totally unconstrained handwritten numerals

affine invariant recognition of gray scale characters using global affine transformation correlation describes a technique of gray scale character recognition that offers both noise tolerance and affine invariance the key ideas are twofold first is the use of normalized cross correlation as a matching measure to realize noise tolerance second is the application of global affine transformation gat to the input image so as to achieve affine invariant correlation with the target image in particular optimal gat is efficiently determined by the successive iteration method using topographic features of gray scale images as matching constraints we demonstrate the high matching ability of the proposed gat correlation method using gray scale images of numerals subjected to random gaussian noise and a wide range of affine transformation moreover extensive recognition experiments show that the achieved recognition rate of 94 3 percent against rotation within 30 degrees scale change within 30 percent and translation within 20 percent of the character width along with random gaussian noise is sufficiently high compared to the 42 8 percent offered by simple correlation

periodic solutions of periodic delay lotka volterra equations and systems abstract by using the continuation theorem of coincidence degree theory sufficient and realistic conditions are obtained for the existence of positive periodic solutions for both periodic lotka volterra equations and systems with distributed or state dependent delays our results substantially extend and improve existing results

oscillation and global attractivity in a nonlinear delay periodic model of respiratory dynamics abstract in this paper we shall consider the nonlinear delay differential equation where m and n are positive integers and v t and t are positive periodic functions of period in the nondelay case we shall show that has a unique positive periodic solution x t and provides sufficient conditions for the global attractivity of x t in the delay case we shall present sufficient conditions for the oscillation of all positive solutions of about x t and establish sufficient conditions for the global attractivity of x t

positive periodic solutions for a class of higher dimensional state dependent delay functional differential equations with feedback control we use the krasnosel skii s fixed point theorem for cones to study the existence of positive periodic solutions of the following a class of higher dimensional state dependent delay functional differential equations with feedback controlx t a t x t f t x t x t t t x t u t a t u t b t u t c t x h t x t moreover we apply our results obtained in this paper to some population model