existence of solutions to fuzzy differential equations with generalized hukuhara derivative via contractive like mapping principles abstract we study the existence and uniqueness of solution for fuzzy initial value problems in the setting of a generalized hukuhara derivative and by using some recent results of fixed point of weakly contractive mappings on partially ordered sets

coupled fixed point theorems for nonlinear contractions in partially ordered metric spaces abstract we introduce the concept of a mixed g monotone mapping and prove coupled coincidence and coupled common fixed point theorems for such nonlinear contractive mappings in partially ordered complete metric spaces presented theorems are generalizations of the recent fixed point theorems due to bhaskar and lakshmikantham t g bhaskar v lakshmikantham fixed point theorems in partially ordered metric spaces and applications nonlinear anal tma 65 2006 1379 1393 and include several recent developments

common fixed points for maps on cone metric space the purpose of this paper is to generalize and to unify fixed point theorems of das and naik ciric jungck huang and zhang on complete cone metric space

iterative selection methods for the common fixed point problems in a banach space many problems encountered in applied mathematics can be recast as the problem of selecting a particular common fixed point of a countable family of non expansive mappings in banach space in the paper under the hypotheses that e is a reflexive banach space which has a weakly continuous duality mapping j with gauge function several viscosity approximation methods are investigated for finding a common fixed point of non expansive mapping sequences

generalized weak contractions in partially ordered metric spaces recent results of doric d doric common fixed point for generalized j f weak contractions appl math lett 22 2009 1896 1900 on generalized weakly contractive mappings are extended to the setting of partially ordered metric spaces thus generalization of fixed point results of harjani and sadarangani j harjani k sadarangani fixed point theorems for weakly contractive mappings in partially ordered sets nonlinear anal 71 2009 3403 3410 is obtained some applications are presented examples are given to show that our results are proper generalizations of the existing ones

particle filters for state estimation of jump markov linear systems jump markov linear systems jmls are linear systems whose parameters evolve with time according to a finite state markov chain in this paper our aim is to recursively compute optimal state estimates for this class of systems we present efficient simulation based algorithms called particle filters to solve the optimal filtering problem as well as the optimal fixed lag smoothing problem our algorithms combine sequential importance sampling a selection scheme and markov chain monte carlo methods they use several variance reduction methods to make the most of the statistical structure of jmls computer simulations are carried out to evaluate the performance of the proposed algorithms the problems of on line deconvolution of impulsive processes and of tracking a maneuvering target are considered it is shown that our algorithms outperform the current methods

brief paper detection and estimation for abruptly changing systems the problem of state estimation and system structure detection for discrete stochastic dynamical systems with parameters which may switch among a finite set of values is considered the switchings are modelled by a markov chain with known transition probabilities a brief survey and a unified treatment of the existing suboptimal algorithms are provided the optimal algorithms require exponentially increasing memory and computations with time simulation results comparing the various suboptimal algorithms are presented

coincidence point theorem for generalized weakly contractions in ordered metric spaces abstract in this article we establish two coincidence point theorems for four mappings satisfying a generalized weakly contractive condition in ordered metric space and apply it to find new coincidence point and common fixed point results we furnish suitable examples to demonstrate the validity of the hypotheses of our results also we give an existence theorem for common solution of two integral equations

on iterations methods for zeros of accretive operators in banach spaces in this paper three iterations are designed to approach zeros of set valued accretive operators in banach spaces the first one is the continuous picard type iteration involving the resolvent the second one is the approximate picard type iteration involving the resolvent and the third one is the halpern type iteration involving the resolvent some strong convergence theorems for three iterations are proved

fixed point theorems and the ulam hyers stability in non archimedean cone metric spaces abstract let x p be a metric space with a k valued non archimedean metric p in this paper we prove the existence and approximation of a fixed point for operators f x x satisfying the contractive condition in the form p f x f y q p x y where q k k is an increasing operator then we study the generalized ulam hyers stability of fixed point equations we next obtain an extension of the krasnoselskii fixed point theorem for the sum of two operators finally an application to functional equations is given

convergence of composite iterative methods for finding zeros of accretive operators abstract strong convergence theorems on composite iterative schemes by the viscosity approximation methods for finding a zero of an accretive operator are established in banach spaces the main results generalize the recent corresponding results of aoyama et al k aoyama y kimura w takahashi m toyoda approximation of common fixed points of a countable family of nonexpansive mappings in banach spaces nonlinear anal 67 2007 2350 2360 ceng et al l c ceng a r khan q h ansari j c yao strong convergence of composite iterative schemes for zeros of m accretive operators in banach spaces nonlinear anal 70 2009 1830 1840 kim and xu t h kim h k xu strong convergence of modified mann iterations nonlinear anal 61 2005 51 60 and xu h k xu strong convergence of an iterative method for nonexpansive and accretive operators j math anal appl 314 2006 631 643 to viscosity methods in a strictly convex and reflexive banach space having a uniformly g teaux differentiable norm our results also improve the corresponding results of t d benavides g l acedo h k xu iterative solutions for zeros of accretive operators math nachr 248 249 2003 62 71 r chen z zhu viscosity approximation fixed points for nonexpansive and m accretive operators fixed point theory appl 2006 2006 1 10 s kamimura w takahashi approximation solutions of maximal monotone operators in hilbert spaces j approx theory 106 2000 226 240 p e mainge viscosity methods for zeroes of accretive operators j approx theory 140 2 2006 127 140 k nakajo strong convergence to zeros of accretive operators in banach spaces j nonlinear convex anal 7 2006 71 81

common fixed points for self mappings on compact metric spaces in this paper we obtain a result of existence of points of coincidence and of common fixed points for two self mappings on compact metric spaces satisfying a contractive condition of suzuki type we also present some examples to illustrate our results moreover using the scalarization method of du we deduce a result of common fixed point in compact cone metric spaces

on line inference for hidden markov models via particle filters we consider the on line bayesian analysis of data by using a hidden markov model where inference is tractable conditional on the history of the state of the hidden component a new particle filter algorithm is introduced and shown to produce promising results when analysing data of this type the algorithm is similar to the mixture kalman filter but uses a different resampling algorithm we prove that this resampling algorithm is computationally efficient and optimal among unbiased resampling algorithms in terms of minimizing a squared error loss function in a practical example that of estimating break points from well log data our new particle filter outperforms two other particle filters one of which is the mixture kalman filter by between one and two orders of magnitude

some coincidence point results in ordered b metric spaces and applications in a system of integral equations the aim of this paper is to present some coincidence point results for four mappings satisfying generalized j f weakly contractive condition in the framework of ordered b metric spaces an example and an application are also provided to support our results

viscosity approximation methods with weak contraction for l lipschitzian pseudocontractive self mapping abstract in this paper under the framework of real reflexive banach space which admits a weakly sequentially continuous duality mapping from e to e we study the strong convergence of an implicit and an explicit composite viscosity approximation algorithm i and ii respectively for a pseudocontractive mapping t by using the weakly contractive mapping f as follows i x t s t f x t s 1 t y t s y t s s x t s 1 s t x t s and ii x n 1 n f x n 1 n y n y n n x n 1 n t x n n 0 our results unify improve and complement several recent ones existing in the current literature

some fixed point theorems using weaker meir keeler function in metric spaces with w distance abstract in the present paper we prove some new fixed point theorems for self mappings defined on a complete metric space with a w distance these results extend some previous fixed point theorems in this field to more general contractive conditions in the setting of w distances for selfmappings which satisfy certain weaker meir keeler conditions

iterative approximation for a zero of accretive operator and fixed points problems in banach space abstract in this paper we introduced an iteration scheme for viscosity approximation for a zero of accretive operator and fixed points problems in a reflexive banach space with weakly continuous duality mapping a new iterative sequence is introduced and strong convergence of the algorithm xn is proved the results improve and extend the results of hu and liu l hu and l liu a new iterative algorithm for common solutions of a finite family of accretive operators nonlinear anal 70 2009 2344 2351 and some others

approximation of fixed points of weakly contractive nonself maps in banach spaces abstract let k be a closed convex subset of a real uniformly smooth banach space e suppose k is a nonexpansive retract of e with p as the nonexpansive retraction let t k e be a d weakly contractive map such that a fixed point x int k of t exists it is proved that a descent like approximation sequence converges strongly to x furthermore if k is a nonempty closed convex subset of an arbitrary real banach space and t k k is a uniformly continuous d weakly contractive map with f t x k tx x it is proved that a descent like approximation sequence converges strongly to x f t

a scattering chamber approach for solving finite rough surface scattering problems in this paper a new method is derived for the computation of scattering from a finite rough free surface the free surface is infinite in extent but only a portion of it is rough in order to reduce the amount of numerical computation for such a problem it is desirable to restrict the computations to the interval of roughness even for remote sources and receivers this can be easily done in the case that the rough portion of the surface is only directed into the surrounding fluid medium in this case the use of the appropriate half space green s function will restrict the integral equation to the interval of roughness only however for general deformations this green s function cannot be used the use of truncated integral equations utilizing the free space green s function is discussed an alternate approach is then described a system of boundary conditions is derived for a finite curve containing the interval of roughness and a surrounding contour in the fluid half space the resulting equations are solved using the method of wave field superposition the derived method is also easily generalized to the case that the rough surface under consideration is the upper boundary of a waveguide

almost periodicity of set valued functions and set dynamic equations on time scales in this paper we first propose the concept of the almost periodicity of set valued functions on almost periodic time scales then based on the exponential dichotomy we discuss the existence and uniqueness of almost periodic solutions of set dynamic equations on time scales as an application several examples are presented to exhibit that one can obtain the existence of almost periodic solutions to interval valued dynamic equations or fuzzy dynamic equations and their discrete counterparts in a united means

common fixed points of almost generalized contractive mappings in ordered metric spaces the existence theorems of common fixed points for two weakly increasing mappings satisfying an almost generalized contractive condition in ordered metric spaces are proved some comparative example are constructed which illustrate the values of the obtained results in comparison to some of the existing ones in literature

best proximity point theorems an exploration of a common solution to approximation and optimization problems abstract given a non self mapping t a b in the setting of a metric space this work concentrates on the resolution of the non linear programming problem of globally minimizing the real valued function x d x tx thereby yielding an optimal approximate solution to the equation tx x an iterative algorithm is also presented to compute a solution of such problems as a sequel it is possible to compute an optimal approximate solution to some non linear equations

fixed point theorems for weakly contractive mappings in partially ordered sets abstract the purpose of this paper is to present some fixed point theorems for weakly contractive maps in a complete metric space endowed with a partial order

the shifted rayleigh mixture filter for bearings only tracking of maneuvering targets this paper introduces the shifted rayleigh mixture filter srmf which is based on jump markov linear systems the formulation permits the presence of clutter for bearings only tracking problems involving maneuvering targets the conditional density of the target state given the available measurements evolves as a growing mixture of probability density functions associated with a history of manoeuvre modes similar to other mixture algorithms the srmf approximates this conditional density by a gaussian mixture of fixed order unlike the extended or unscented kalman filters the shifted rayleigh filter incorporates an exact calculation of the posterior density when the prior is assumed to be gaussian given the latest bearings measurement computer simulations are provided to demonstrate the performance of the algorithm

coincidence point theorems on metric spaces via simulation functions due to its possible applications fixed point theory has become one of the most useful branches of nonlinear analysis in a very recent paper khojasteh et al introduced the notion of simulation function in order to express different contractivity conditions in a unified way and they obtained some fixed point results in this paper we slightly modify their notion of simulation function and we investigate the existence and uniqueness of coincidence points of two nonlinear operators using this kind of control functions

fixed point theorems for non self mappings in symmetric spaces under φ weak contractive conditions and an application to functional equations in dynamic programming in this paper we prove some common fixed point theorems for two pairs of non self weakly compatible mappings enjoying common limit range property besides satisfying a generalized f weak contractive condition in symmetric spaces we furnish some illustrative examples to highlight the realized improvements in our results over the corresponding relevant results of the existing literature we extend our main result to four finite families of mappings in symmetric spaces using the notion of pairwise commuting mappings finally we utilize our results to discuss the existence and uniqueness of solutions of certain system of functional equations arising in dynamic programming

on ψ φ weakly contractive condition in partially ordered metric spaces recently heman kumar nashine and bessem samet h k nashine b samet fixed point results for mappings satisfying j f weakly contractive condition in partially ordered metric spaces nonlinear anal 74 2011 2201 2209 studied some coincidence fixed point and common fixed point theorems for two mappings satisfying j f weakly contractive condition in an ordered complete metric space in the present paper we study some coincidence fixed point and common fixed point theorems for three mappings s t and r satisfying j f weakly contractive condition in an ordered complete metric space where the mappings s and t are assumed to be weakly increasing with respect to r our results generalize several well known results in the literature

equivalent theorems of the convergence between proximal type algorithms abstract the main aim of this work is to give the equivalence of the convergence between proximal type algorithms our convergence analysis covers rockafellar type proximal point algorithm with a weak contraction for finding zeros of accretive operators as well as browder and halpern type iterations and viscosity approximation methods for finding fixed points of nonexpansive type mappings in banach spaces we also provide simple proofs of some results of wong sahu and yao n c wong d r sahu j c yao solving variational inequalities involving nonexpansive type mappings nonlinear anal 69 12 2008 4732 4753

existence and data dependence of fixed points for multivalued operators on gauge spaces abstract the purpose of this note is to present some fixed point and data dependence theorems in complete gauge spaces and in hyperconvex metric spaces for the so called meir keeler multivalued operators and admissible multivalued a contractions our results extend and generalize several theorems of espinola and kirk r espinola w a kirk set valued contractions and fixed points nonlinear anal 54 2003 485 494 and rus petrusel and sint m rian i a rus a petrusel a sint m rian data dependence of the fixed point set of some multivalued weakly picard operators nonlinear anal 52 2003 1947 1959

common fixed point results for noncommuting mappings without continuity in cone metric spaces the existence of coincidence points and common fixed points for mappings satisfying certain contractive conditions without appealing to continuity in a cone metric space is established these results generalize several well known comparable results in the literature

some generalizations of caristi s fixed point theorem with applications to the fixed point theory of weakly contractive set valued maps and the minimization problem abstract in this paper we first prove some generalizations of caristi s fixed point theorem then we give some applications to the fixed point theory of weakly contractive set valued maps and the minimization problem

a new numerical method for rough surface scattering calculations a new approach to solving the magnetic field integral equation mfie for the current induced on a infinite perfectly conducting rough surface is presented by splitting the propagator matrix into contributions from the left and from the right of the point of observation a second kind integral equation can be formed with a new born term and a new kernel following discretization of this new integral equation the unknown currents can be determined more rapidly and with significantly less storage requirements than conventional lu decomposition where the time saving factor is roughly n 3 where n is the number of current samples on the surface and the usual storage requirements associated with matrix inversion are eliminated while the new born term is usually adequate for scattered field calculations the new discretized integral equation can be iterated to amy desired accuracy with no apparent convergence problems results are presented for one dimensional rough surfaces with rms heights exceeding one wavelength and rms slopes exceeding 40 which illustrate the robustness of the new born term

cyclic generalized ψ weakly contractive mappings and fixed point results with applications to integral equations abstract we introduce a cyclic generalized weakly contractive mappings for a map in a metric space and originate existence and uniqueness results of fixed points for such mappings examples are given to support the usability of our results at the end of the results an application to the study of existence and uniqueness of solutions for a class of nonlinear integral equations is presented

generalized contractions in partially ordered metric spaces and applications to ordinary differential equations the purpose of this paper is to present some fixed point theorems in a complete metric space endowed with a partial order by using altering distance functions we also present some applications to first and second order ordinary differential equations

coupled common fixed point theorems for w compatible mappings in ordered cone metric spaces abstract we establish coupled coincidence point results for mixed g monotone mappings under general contractive conditions in partially ordered cone metric spaces over solid cones we also present results on existence and uniqueness of coupled common fixed points our results generalize extend and unify several well known comparable results in the literature to illustrate our results and to distinguish them from the earlier ones we equip the paper with examples

a best proximity point theorem for weakly contractive non self mappings abstract let us consider a map t a b where a and b are two nonempty subsets of a metric space x the aim of this article is to provide sufficient conditions for the existence of a unique point x in a called the best proximity point which satisfies d x t x dist a b inf d a b a a b b our result generalizes a result due to rhoades b e rhoades some theorems on weakly contractive maps nonlinear analysis tma 47 2001 2683 2693 and hence it provides an extension of banach s contraction principle to the case of non self mappings

multilevel fast multipole algorithm for general targets on a half space interface the multilevel fast multipole algorithm mlfma is considered for scattering from an electrically large conducting or dielectric target resting on the interface of a dielectric half space we focus on analysis of the half space green s function such that it is computed efficiently and accurately while retaining a form that is applicable to an mlfma analysis attention is also directed toward development of a simple preconditioner to accelerate convergence of the conjugate gradient solver the utility of the model is examined for several applications including scattering from an electrically large vehicle trees and rough dielectric interfaces in the presence of a dielectric half space background

coupled fixed point theorems for a generalized meir keeler contraction in partially ordered metric spaces abstract let x be a non empty set and f x x x be a given mapping an element x y x x is said to be a coupled fixed point of the mapping f if f x y x and f y x y in this paper we consider the case when x is a complete metric space endowed with a partial order we define generalized meir keeler type functions and we prove some coupled fixed point theorems under a generalized meir keeler contractive condition some applications of our obtained results are given the presented theorems extend and complement the recent fixed point theorems due to bhaskar and lakshmikantham t gnana bhaskar v lakshmikantham fixed point theorems in partially ordered metric spaces and applications nonlinear anal 65 2006 1379 1393

fixed point theorems for generalized weakly contractive mappings we prove a fixed point theorem for a generalized weakly contractive mapping and a fixed point theorem for a pair of weakly contractive mappings we also show that these mappings satisfy properties p and q

fixed point theorems in partially ordered metric spaces and applications abstract we prove a fixed point theorem for a mixed monotone mapping in a metric space endowed with partial order using a weak contractivity type of assumption besides including several recent developments our theorem can be used to investigate a large class of problems as an application we discuss the existence and uniqueness of solution for a periodic boundary value problem

mixture kalman filters in treating dynamic systems sequential monte carlo methods use discrete samples to represent a complicated probability distribution and use rejection sampling importance sampling and weighted resampling to complete the on line filtering task we propose a special sequential monte carlo method the mixture kalman filter which uses a random mixture of the gaussian distributions to approximate a target distribution it is designed for on line estimation and prediction of conditional and partial conditional dynamic linear models which are themselves a class of widely used non linear systems and also serve to approximate many others compared with a few available filtering methods including monte carlo methods the gain in efficiency that is provided by the mixture kalman filter can be very substantial another contribution of the paper is the formulation of many non linear systems into conditional or partial conditional linear form to which the mixture kalman filter can be applied examples in target tracking and digital communications are given to demonstrate the procedures proposed

fixed points of weak contractions in cone metric spaces abstract cone metric spaces are generalizations of metric spaces where the metric is banach space valued weak contractions are generalizations of the banach s contraction mapping which have been studied by several authors in the present work we establish a unique fixed point result for weak contractions in cone metric spaces our result is supported by an example

coupled fixed point results for ψ φ weakly contractive mappings in ordered g metric spaces in this paper we establish coupled coincidence and common coupled fixed point theorems for j f weakly contractive mappings in ordered g metric spaces presented theorems extend generalize and improve many existing results in the literature an example is given

coincidence and common fixed point theorems for a sequence of mappings in ordered metric spaces in this article the existence of coincidence points and common fixed points for a sequence of mappings satisfying generalized weakly contractive conditions which involves altering distance functions without exploiting the notion of continuity of any map involved therein in a ordered metric space is proved an example is given to support the usability of our results

generalized fractal transforms and self similar objects in cone metric spaces we use the idea of a scalarization of a cone metric to prove that the topology generated by any cone metric is equivalent to a topology generated by a related metric we then analyze the case of an ordering cone with empty interior and we provide alternative definitions based on the notion of quasi interior points finally we discuss the implications of such cone metrics in the theory of iterated function systems and generalized fractal transforms and suggest some applications in fractal based image analysis

fixed point theorems for nonlinear contractions in kaleva seikkala s type fuzzy metric spaces in this paper the existence and unicity of fixed points for mappings in fuzzy metric spaces in the sense of kaleva and seikkala is discussed nonlinear contractions of the boyd wong s type alber guerre delabriere s type and kannan reich s type are considered and several new fixed point theorems for these contractions in complete fuzzy metric spaces are presented respectively also some error estimates are given for iterations to approximate fixed point previous work with respect to fixed point in fuzzy metric spaces is based on the t conorm max the presented work does away with this restriction by proposing weaker conditions defining a generic class of suitable binary operations as applications the corresponding fixed point theorems for menger probabilistic metric spaces are obtained

fixed point for set valued mappings satisfying an implicit relation in partially ordered metric spaces abstract let x be a partially ordered set and d be a complete metric on x let f g be two set valued mappings on x we obtained sufficient conditions for the existence of common fixed point of f and g satisfying an implicit relation in partially ordered set x

cone metric spaces and fixed point theorems of contractive mappings in this paper we introduce cone metric spaces prove some fixed point theorems of contractive mappings on cone metric spaces

some common fixed point theorems for generalized nonlinear contractive mappings sufficient conditions for the existence of a common fixed point for generalized nonlinear contractive mappings are derived as applications some results on the set of best approximation for this class of mappings are also obtained the proved results generalize and extend various known results in the literature

existence and uniqueness of common fixed points for two multivalued operators in ordered metric spaces in this paper we discuss some new fixed point theorems for a pair of multivalued operators which satisfy weakly generalized contractive conditions our results are the extension and improvement of corresponding results of j harjani and k sadarangani fixed point theorems for weakly contractive mappings in partially ordered sets nonlinear analysis 71 2009 3403 3410 and x zhang common fixed point theorems for some new generalized contractive type mappings j math anal appl 333 2007 780 786 finally some examples are given to illustrate the usability of our results

on some nonlinear problems induced by an abstract maximal element principle abstract in this paper by applying an abstract maximal element principle on quasi ordered sets established by lin and du we obtain a generalized brezis browder principle system vectorial versions of ekeland s variational principle and maximal element principle and a vectorial version of takahashi s nonconvex minimization theorem moreover we investigate the equivalence between scalar versions and vectorial versions of these results

ordered cone metric spaces and fixed point results in this paper we introduce a partial order on a cone metric space and prove a caristi type theorem furthermore we prove fixed point theorems for single valued nondecreasing and weakly increasing mappings and multi valued mappings on an ordered cone metric space

fixed point results for mappings satisfying ψ φ weakly contractive condition in partially ordered metric spaces abstract we establish coincidence fixed point and common fixed point theorems for mappings satisfying weakly contractive condition in an ordered complete metric space some applications of our obtained results are given

fixed points of multivalued operators in ordered metric spaces with applications abstract the purpose of this paper is to present some new hybrid fixed point theorems involving multivalued operators which satisfy weakly generalized contractive conditions in an ordered complete metric space an example of the existence of solutions for a perturbed impulsive hyperbolic differential inclusion with variable times is given to illustrate the usability of our results

fixed points for φ ψ p weakly contractive mappings in metric spaces with w distance the fixed point theorems presented in this paper generalize recent results of dutta and choudhury 3 branciari 2 banach 1 rhoades 9 khan et al 6 kada 5 and rhoades and abbas 10

coincidence and common fixed point results in partially ordered cone metric spaces and applications to integral equations abstract in this paper coincidence and common fixed point results are established in a partially ordered cone metric space an application of our results obtained to prove the existence of a common solution to integral equations is presented

a simplified approach to solving finite rough surface scattering problems in this paper a simplified approach is described for the computation of scattering from finite length rough surfaces in an earlier paper fawcett j acoust soc 118 1348 1357 2005 it was described how to solve such problems by considering a scattering chamber and using the method of wavefield superposition to satisfy the various boundary and continuity conditions in this paper a form of the field in the interior of the scattering chamber is assumed and the solution to the scattering problem is reduced to solving a system of equations just along the rough surface the solution to this system of equations can then be used to compute the scattered or total fields anywhere in the half space the results of this approach are compared to those obtained by other methods

on the use of finite surfaces in the numerical prediction of rough surface scattering method of moments mom based monte carlo calculations are widely used in determining the average radar cross section of randomly rough surfaces it is desirable in these numerical calculations to truncate the scattering surface into as short a length as possible to minimize the solution time however truncating the surface tends to change the solution for the surface fields near the truncation points and may alter the scattered far fields in this paper these end effect errors are examined for one dimensional i e grooved or corduroy surfaces which are gaussian distributed in height and have either a gaussian or a pierson moskowitz spectra in the case of the pierson moskowitz type surface it is shown that a relatively short surface of 80 120 wavelengths can be used to obtain the average backscattered radar cross section for backscattering angles as large as 60 spl deg from normal for a comparatively smooth gaussian surface on the other hand its is shown that the truncation effects can be very significant at moderate backscattering angles also great care should be taken when examining the scattering from gaussian surfaces which are dominated by specular scattering it is shown that in this situation a very large number of calculations may be needed to obtain a good numerical average

strong convergence of iterative methods by strictly pseudocontractive mappings in banach spaces abstract in this paper we deal with fixed point computational problems by strongly convergent methods involving strictly pseudocontractive mappings in smooth banach spaces first we prove that the s iteration process recently introduced by sahu in 14 converges strongly to a unique fixed point of a mapping t where t is strongly pseudocontractive mapping from a nonempty closed and convex subset c of a smooth banach space into itself it is also shown that the hybrid steepest descent method converges strongly to a unique solution of a variational inequality problem with respect to a finite family of i strictly pseudocontractive mappings from c into itself our results extend and improve some very recent theorems in fixed point theory and variational inequality problems particularly the results presented here extend some theorems of reich 1980 1 and yamada 2001 15 to a general class of strictly pseudocontractive mappings in uniformly smooth banach spaces

on cone metric spaces a survey abstract using an old m krein s result and a result concerning symmetric spaces from s radenovic z kadelburg quasi contractions on symmetric and cone symmetric spaces banach j math anal 5 1 2011 38 50 we show in a very short way that all fixed point results in cone metric spaces obtained recently in which the assumption that the underlying cone is normal and solid is present can be reduced to the corresponding results in metric spaces on the other hand when we deal with non normal solid cones this is not possible in the recent paper m a khamsi remarks on cone metric spaces and fixed point theorems of contractive mappings fixed point theory appl 2010 7 pages article id 315398 doi 10 1115 2010 315398 the author claims that most of the cone fixed point results are merely copies of the classical ones and that any extension of known fixed point results to cone metric spaces is redundant also that underlying banach space and the associated cone subset are not necessary in fact khamsi s approach includes a small class of results and is very limited since it requires only normal cones so that all results with non normal cones which are proper extensions of the corresponding results for metric spaces cannot be dealt with by his approach

existence and approximation of fixed points of nonlinear mappings in spaces with weak uniform normal structure it is shown that in a banach space x with weak uniform normal structure every demicontinuous asymptotically regular nearly lipschitzian self mapping t with lim sup n h t n

some notes on the paper cone metric spaces and fixed point theorems of contractive mappings abstract huang and zhang reviewed cone metric spaces in 2007 huang long guang zhang xian cone metric spaces and fixed point theorems of contractive mappings j math anal appl 332 2007 1468 1476 we shall prove that there are no normal cones with normal constant m 1 and for each k 1 there are cones with normal constant m k also by providing non normal cones and omitting the assumption of normality in some results of huang long guang zhang xian cone metric spaces and fixed point theorems of contractive mappings j math anal appl 332 2007 1468 1476 we obtain generalizations of the results

on the vectoral ekeland s variational principle and minimal points in product spaces abstract phelps 13 noticed that the scalar ekeland s variational principle evp is equivalent to the existence of a minimal point of the epigraph of the corresponding function with respect to an appropriate order attouch and riahi 1 showed that evp is equivalent to the existence of maximal points with respect to cones satisfying some additional conditions taking these into account gopfert and tammer 6 7 established a maximal point theorem in a product space the aim of this paper is to obtain several minimal point theorems in product spaces and the corresponding variants of the vectorial evp

a generalized contraction principle with control functions on partial metric spaces partial metric spaces were introduced by matthews in 1994 as a part of the study of denotational semantics of data flow networks in this article we prove a generalized contraction principle with control functions f and j on partial metric spaces the theorems we prove generalize many previously obtained results we also give some examples showing that our theorems are indeed proper extensions

some ordered fixed point results and the property p in 2010 kadelburg et al 7 by providing an example showed that a contraction in an ordered metric space is not necessarily a contraction in the classical sense thus fixed point results in ordered metric spaces are generalizations of ones in metric spaces in a sense in this paper we give some ordered fixed point results for convex contractions and special mappings which satisfy some contraction conditions also we give some results concerning the property p

on the discretization of the integral equation describing scattering by rough conducting surfaces numerical simulations of scattering from one dimensional 1 d randomly rough surfaces with pierson moskowitz p m spectra show that if the kernel or propagator matrix with zeros on its diagonal is used in the discretized magnetic field integral equation mfie the results exhibit an excessive sensitivity to the current sampling interval especially for backscattering at low grazing angles lgas though the numerical results reported in this paper were obtained using the method of ordered multiple interactions momi a similar sampling interval sensitivity has been observed when a standard method of moments mom technique is used to solve the mfie a subsequent analysis shows that the root of the problem lies in the correct discretization of the mfie kernel we found that the inclusion of terms proportional to the surface curvature regarded by some authors as an additional correction in the diagonal of the kernel matrix virtually eliminates this sampling sensitivity effect by reviewing the discretization procedure for mfie we show that these curvature terms indeed must be included in the diagonal in order for the propagator matrix to be represented properly the recommended current sampling interval for scattering calculations with p m surfaces is also given

coincidence and fixed point theorems for generalized ψ φ weak nonlinear contraction in ordered k metric spaces in this paper we establish coincidence and fixed point theorems for a pair of mappings satisfying a new generalized j f weak nonlinear contraction type condition in ordered k metric spaces the presented results generalize and extend the very recent results of choudhury and metiya b s choudhury and n metiya the point of coincidence and common fixed point for a pair of mappings in cone metric spaces computers and mathematics with applications 60 2010 1686 1695

viscosity approximation schemes for fixed point problems and equilibrium problems and variational inequality problems abstract in this paper we first introduce a general iterative scheme by halpern approximation method for finding a common element of the set of solutions of an equilibrium problem the set of solutions of the variational inequality for an infinite family of i inverse strongly monotone mappings and the set of common fixed points for a family of infinitely nonexpansive mappings in a hilbert space then we extend the halpern iterative scheme to a general viscosity approximation scheme by a simple and different method as applications we utilize our results to investigate some convergence problems for strictly pseudocontractive mappings and maximal monotone operators the results obtained in this paper extend and improve the recent ones announced by many others

solving variational inequalities involving nonexpansive type mappings abstract the purpose of this paper is to investigate the asymptotic behavior of algorithms for finding solutions for a certain class of variational inequalities v i d c i f involving nonexpansive type mappings in smooth banach spaces we study the existence of solutions of variational inequalities v i d c i f when d is the set of solutions of zeros of accretive operators or the set of fixed points of nonexpansive mappings or the set of fixed points of pseudocontractive mappings our convergence analysis covers proximal point algorithm for finding zeros of accretive operators as well as functional halpern algorithm for finding fixed points of nonexpansive mappings in banach spaces our results improve a number of results concerned with viscosity approximation methods in the context of weakly contraction mappings

common coupled fixed point theorems in cone metric spaces for w compatible mappings in this paper we introduce the concept of a w compatible mappings to obtain coupled coincidence point and coupled point of coincidence for nonlinear contractive mappings in cone metric space with a cone having non empty interior coupled common fixed point theorems for such mappings are also proved our results generalize extend and unify several well known comparable results in the literature results are supported by three examples

a note on cone metric fixed point theory and its equivalence abstract the main aim of this paper is to investigate the equivalence of vectorial versions of fixed point theorems in generalized cone metric spaces and scalar versions of fixed point theorems in general metric spaces in usual sense we show that the banach contraction principles in general metric spaces and in t v s cone metric spaces are equivalent our theorems also extend some results in huang and zhang 2007 l g huang x zhang cone metric spaces and fixed point theorems of contractive mappings j math anal appl 332 2007 1468 1476 rezapour and hamlbarani 2008 sh rezapour r hamlbarani some notes on the paper cone metric spaces and fixed point theorems of contractive mappings j math anal appl 345 2008 719 724 and others

the validity of the perturbation approximation for rough surface scattering using a gaussian roughness spectrum the validity of the perturbation approximation for rough surface scattering is examined 1 by comparison with exact results obtained by solving an integral equation and 2 through comparison of low order perturbation predictions with higher order predictions the pressure release boundary condition is assumed and the field quantity calculated is the bistatic scattering cross section a gaussian roughness spectrum is used and the surfaces have height variations in only one direction it is found in general that the condition kh 1 k is the acoustic wavenumber h is the rms surface height is insufficient to guarantee the accuracy of first order or higher order perturbation theory when the surface correlation length l becomes too large or too small with h held fixed higher order perturbation terms can make larger contributions to the scattering cross section than lower order terms an explanation for this result is given the regions of validity for low order perturbation theory are also given th

endpoints and fixed points of set valued contractions in cone metric spaces abstract in this paper we introduce the concept of set valued contractions in cone metric spaces and establish new endpoint and fixed point theorems for such contractions the paper includes examples

equivalent conditions for generalized contractions on ordered metric spaces abstract we establish a geometric lemma giving a list of equivalent conditions for some subsets of the plane as its application we get that various contractive conditions using the so called altering distance functions coincide with classical ones we consider several classes of mappings both on metric spaces and ordered metric spaces in particular we show that unexpectedly some very recent fixed point theorems for generalized contractions on ordered metric spaces obtained by harjani and sadarangani j harjani k sadarangani generalized contractions in partially ordered metric spaces and applications to ordinary differential equations nonlinear anal 72 2010 1188 1197 and amini harandi and emami a amini harandi h emami a fixed point theorem for contraction type maps in partially ordered metric spaces and application to ordinary differential equations nonlinear anal 72 2010 2238 2242 do follow from an earlier result of o regan and petrusel d o regan and a petrusel fixed point theorems for generalized contractions in ordered metric spaces j math anal appl 341 2008 1241 1252

tapered wave with dominant polarization state for all angles of incidence typical applications of the method of moments mom to rough surface three dimensional 3 d electromagnetic scattering require a truncation of the surface considered and call for a tapered incident wave it is shown how such a wave can be constructed as a superposition of plane waves avoiding problems near both normal and grazing incidence and providing clean footprints and clear polarization at all angles of incidence the proposed special choice of polarization vectors removes an irregularity at the origin of the wavenumber space and leads to a least squared error property of the wave issues in the application to 3 d scattering from an object over a rough surface are discussed approximate 3 d scalar and vector tapered waves which can be evaluated without resorting to any numerical integrations are derived and important limitations to the accuracy and applicability of these approximations are pointed out

a new gaussian mixture algorithm for gmti tracking under a minimum detectable velocity constraint this paper introduces a new methodology to account for doppler blind zone constraints arising for example in ground moving target indicator gmti tracking applications in such problems target measurements are suppressed when the range rate doppler of the target drops below a specified threshold in magnitude the minimum detectable velocity the proposed method employing gaussian mixture approximations to the filtering density differs from earlier gaussian mixture approaches in the way missed measurements are modelled the distinctive feature of the algorithm as compared with other gaussian mixture filters is that it is based on an exact calculation of the filtering density when a measurement is not recorded algorithms that result from applying this methodology are simple to implement and computationally undemanding simulation results indicate a uniform improvement in estimation accuracy over that of earlier proposed analytic techniques and a tracking performance comparable to that of state of the art particle filters

generalized coupled fixed points and its application to a class of systems of functional equations arising in dynamic programming in this paper we introduce the definition of generalized coupled fixed point in the space of the bounded functions on a set s and we prove a result about the existence and uniqueness of such points as an application of our result we study the problem of existence and uniqueness of solutions for a class of systems of functional equations which appears in dynamic programming

the point of coincidence and common fixed point for a pair of mappings in cone metric spaces in this paper the existence of a point of coincidence and a common fixed point for two weakly compatible maps on a cone metric space has been established the two mappings are assumed to satisfy certain weak inequalities supporting examples are also given