a compact covering method to exploit embedding capacity for matrix encoding recently a number of covering schemes proposed to exploit embedding capacity in covering images using matrix encoding when binary secret data include a high frequency of repeated bit blocks a preprocessing phase is employed to compress secret data prior to the embedding process regardless of whether the compressed secret data still contain some repeated bit blocks this paper proposes two novel compact covering schemes compact covering scheme ccs and intelligent compact covering scheme iccs which directly compress and conceal the repeated bit blocks of secret data bits into covering images within a single phase the proposed schemes can exploit the embedding capacity and increase the embedding efficiency by reducing the required encoding operations in addition the proposed iccs scheme can indicate up to which degree of repeated bit blocks of secret data it can take advantage of in order to improve the embedding capacity experimental results demonstrate that the proposed iccs method can significantly improve the embedding capacity when the ratio of the repeated bit blocks over the total number of blocks is low the proposed schemes are feasible for actual data hiding applications

nodal ground state solution to a biharmonic equation via dual method abstract using the dual method we establish the existence of a nodal ground state solution for the following class of problems 2 u f u in u bu 0 on where r n n 1 is a smooth bounded domain 2 is the biharmonic operator b or b and f is a c 1 function having subcritical growth

stability analysis for neutral stochastic differential equation of second order driven by poisson jumps this paper studies the existence uniqueness and exponential stability in mean square for the mild solution of neutral second order stochastic partial differential equations with infinite delay and poisson jumps by utilizing the banach fixed point theorem first the existence and uniqueness of the mild solution of neutral second order stochastic differential equations is established then the mean square exponential stability for the mild solution of the stochastic system with poisson jumps is obtained with the help of an established integral inequality

controllability of semilinear stochastic systems in hilbert spaces we study the weak approximate and complete controllability properties of semilinear stochastic systems assuming controllability of the associated linear systems the results are obtained by using the banach fixed point theorem applications to stochastic heat equation are given

controllability of linear stochastic systems we discuss several concepts of controllability for partially observable stochastic systems complete controllability approximate controllability and stochastic controllability we show that complete and approximate controllability notions are equivalent and in turn they are equivalent to the stochastic controllability for linear stochastic systems controlled with gaussian processes we derive necessary and sufficient conditions for these concepts of controllability these criteria reduce to the well known rank condition

variational methods for non differentiable functionals and their applications to partial differential equations the interest in extending the theory of nonlinear partial differential equations pde to pde with discontinuous nonlinearities dnde has been increasing daily the reasons are twofold 1 many free boundary problems may be reduced to boundary value problems of dnde cf chang 16 71 chang and jiang 9 and fleishman and mahar 121 2 sometimes in dealing with a pde problem it is beneficial to put the original pde into a large category for instance dnde cf chang 7 simply speaking a dnde is as follows

existence of a nontrivial solution for a class of hemivariational inequality problems at double resonance abstract in this paper we discuss a class of semilinear elliptic hemivariational inequality problems by using the nonsmooth minimax principle for locally lipschitz functions we establish the existence of a nontrivial solution for the semilinear elliptic hemivariational inequality problem where incomplete double resonance occurs at infinity between two distinct consecutive eigenvalues

existence of solutions for dirichlet elliptic problems with discontinuous nonlinearity abstract in this paper we concern with definite sign and sign changing solutions of a class of discontinuous problems by using the dual method we overcome the difficulty of non differentiability and obtain the existence results of definite sign solution and a sign changing solutions on the nehari manifold for the discontinuous problems some continuous results are extended to the discontinuous cases

ground state sign changing solutions for kirchhoff type problems in bounded domains abstract in the present paper we consider the existence of ground state sign changing solutions for a class of kirchhoff type problems 0 1 a b u 2 d x u f u x u 0 x where r n is a bounded domain with a smooth boundary n 1 2 3 a 0 b 0 and f c r r under some weak assumptions on f with the aid of some new analytical skills and non nehari manifold method we prove that 0 1 possesses one ground state sign changing solution u b and its energy is strictly larger than twice that of the ground state solutions of nehari type furthermore we establish the convergence property of u b as the parameter b 0 our results improve and generalize some results obtained by w shuai 2015 34

sign changing solutions to a gauged nonlinear schrodinger equation abstract we study the existence and asymptotic behavior of the least energy sign changing solutions to a gauged nonlinear schrodinger equation u u h 2 x x 2 x h s s u 2 s d s u u p 2 u x r 2 u h r 1 r 2 where 0 p 6 and h s 1 2 0 s r u 2 r d r combining constraint minimization method and quantitative deformation lemma we prove that the problem possesses at least one least energy sign changing solution u which changes sign exactly once moreover we show that the energy of u is strictly larger than two times of the ground state energy finally the asymptotic behavior of u as 0 is also analyzed

the upper and lower bounds of the information hiding capacity of digital images the information hiding capacity of a digital image is the maximum information that can be hidden in that image while the lower limit of information hiding is the minimum detectable information capacity this paper proposes a new method of information hiding capacity bounds analysis that is based on the neural network theories of attractors and attraction basins with this method the processes for determining upper and lower limits of information hiding are unified within a single theoretical framework results of research show that the theory of attraction basins of neural networks can be used to determine the upper limit of information hiding and the theory of attractors of neural networks can be used to determine the lower limit of information hiding

approximate controllability of second order semilinear stochastic system with nonlocal conditions in this paper the approximate controllability of second order semilinear stochastic system involving nonlocal conditions is studied by using sadovskii s fixed point theorem with stochastic analysis theory we derive a new set of sufficient conditions for the approximate controllability of second order semilinear stochastic system with nonlocal conditions under the assumption that the corresponding linear system is approximately controllable finally an application to a second order semilinear stochastic system with nonlocal initial condition is provided to illustrate the obtained theory

approximate controllability for stochastic evolution inclusions of clarke s subdifferential type in this paper we deal with the approximate controllability of stochastic evolution inclusions of clarke s subdifferential type firstly by using stochastic analysis nonsmooth analysis theory of operator semigroups and fixed point theorems of multivalued maps we show the existence of mild solutions for the stochastic evolution inclusions then we provide a sufficient condition to guarantee the approximate controllability of the stochastic evolution inclusions actually our results cover a broader class of inclusion problems involving time depending operators finally an example is included to illustrate the applicability of the main results

the dual variational principle and elliptic problems with discontinuous nonlinearities on etudie des problemes aux valeurs limites elliptiques du type u f u p x x u 0 x ou r n est un domaine borne et f peut avoir des discontinuites on cherche des solutions en utilisant le principe d action duale de clarke

approximate controllability of semilinear deterministic and stochastic evolution equations in abstract spaces various sufficient conditions for approximate controllability of linear evolution systems in abstract spaces have been obtained but approximate controllability of semilinear control systems usually requires some complicated and limited assumptions in this paper we show the approximate controllability of the abstract semilinear deterministic and stochastic control systems under the natural assumption that the associated linear control system is approximately controllable the results are obtained using new properties of symmetric operators which are proved in this paper compact semigroups the schauder fixed point theorem and or the contraction mapping principle

a variational approach to discontinuous problems with critical sobolev exponents abstract we employ variational techniques to study the existence and multiplicity of positive solutions of semilinear equations of the form u h x h u a uq u2 1 in rn where a 0 are parameters h x is both nonnegative and integrable on rn h is the heaviside function 2 is the critical sobolev exponent and 0 q

controllability of non linear stochastic systems complete controllability of a semi linear stochastic system assuming controllability of the associated linear sytem is studied it is also shown that a non linear stochastic system is locally null controllable provided that the corrsponding linearized system is controllable

a note on exponential stability for second order neutral stochastic partial differential equations with infinite delays in the presence of impulses in this work the problem on the exponential stability for second order neutral stochastic partial differential equations with infinite delays is considered in the presence of impulses under some conditions by employing the new integral inequality technique some algebraic criteria of stability are established for the concerned problem and some existing results are generalized and improved finally an illustrative example is given to demonstrate the effectiveness of the obtained results

on controllability conception for stochastic systems the controllability notions for partially observed stochastic systems are defined their relation with complete and approximate controllabilities is shown in particular it is proven that the approximate controllability condition is necessary and the complete controllability condition is sufficient for the partially observed linear gaussian control system to attain the arbitrarily small neighborhood of each point in the state space with probability arbitrarily closely to one

adaptive embedding techniques for vq compressed images an embedding algorithm which can adaptively embed a binary message into a vq compressed image is proposed in this paper the proposed algorithm is divided into three phases in the codeword grouping phase a new group of codewords is initiated by the two most similar codewords which do not belong to any group for each codeword which does not belong to any group if the codeword is similar to all of the codewords in the group it will be added to the group in the embedding phase each codeword in a group will be assigned to embed a certain sub message whose length is determined by the number of codewords in the group the more codewords a group has the higher the embedding capacity of a codeword in the group will be in the extracting phase given a codeword and the number of codewords in the group to which the codeword belongs the embedded message can be extracted from the codeword by simply determining the order of the codeword in the group experimental results show that the proposed algorithm performs better than previous algorithms with regard to embedding capacity and image quality for the test images when the embedding capacity is less than 5bits per codeword index the difference of the psnr values between the stego image and its vq compressed cover image will be no more than 5db on average

existence and multiplicity of solutions for semilinear hemivariational inequalities at resonance abstract in this paper we study semilinear hemivariational inequalities at resonance assuming a partially anticoercive nonsmooth potential we prove an existence and a multiplicity theorem the method of the proof is variational and in the multiplicity result we employ the nonsmooth local linking theorem