http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Thu, 23 May 2013 19:02:58 +0000 http://www.hindawi.com/journals/jmath/2013/502635/ We investigate a variant of the stochastic logistic model that allows individual variation and time-dependent infection and recovery rates. The model is described as a heterogeneous density dependent Markov chain. We show that the process can be approximated by a deterministic process defined by an integral equation as the population size grows. Yilun Shang Copyright © 2013 Yilun Shang. All rights reserved. Wed, 22 May 2013 11:08:27 +0000 http://www.hindawi.com/journals/jmath/2013/721868/ A mathematical model to control the vibrations of a rectangular plate is constructed with an aim to assist engineers in designing and fabrication of various structures used in the field of science and technology, mostly used in satellite and aeronautical engineering. The present study is related to the analysis of free vibrations of nonhomogeneous rectangular plate clamped at all the four edges. Authors studied the bilinear effect of thickness as well as temperature variations in both and directions. Variation in Poisson's ratio is also considered linearly in -direction due to nonhomogeneity. Rayleigh-Ritz method is used to analyze the frequencies for the first two modes of vibrations for different values of thermal gradient, nonhomogeneity constant, taper constants and aspect ratio. All the numerical computations have been performed for an alloy of aluminum, that is, duralumin. All the results are presented in the form of graphs. Anupam Khanna and Ashish Singhal Copyright © 2013 Anupam Khanna and Ashish Singhal. All rights reserved. Mon, 20 May 2013 10:52:43 +0000 http://www.hindawi.com/journals/jmath/2013/967045/ A fixed point theorem is presented for single-valued map with using generalized -weak contractive condition involving various combinations of on a complete metric space. Our result is an extension as well as a generalization of Alber and Guerre-Delabriere (1997) in particular. It also generalizes the results of Rhoades (2001), Choudhury and Dutta, (2000), and Dutta and Choudhury, (2008). Penumurthy Parvateesam Murthy and K. N. V. V. Vara Prasad Copyright © 2013 Penumurthy Parvateesam Murthy and K. N. V. V. Vara Prasad. All rights reserved. Sun, 12 May 2013 14:13:20 +0000 http://www.hindawi.com/journals/jmath/2013/821762/ This paper is devoted to study further properties of generalized Mittag-Leffler function associated with Weyl fractional integral and differential operators. A new integral operator depending on Weyl fractional integral operator and containing in its kernel is defined and studied, namely, its boundedness. Also, composition of Weyl fractional integral and differential operators with the new operator is established. Ahmad Faraj, Tariq Salim, Safaa Sadek, and Jamal Ismail Copyright © 2013 Ahmad Faraj et al. All rights reserved. Thu, 09 May 2013 12:52:16 +0000 http://www.hindawi.com/journals/jmath/2013/841837/ We define two new general integral operators for certain analytic functions in the unit disc and give some sufficient conditions for these integral operators on some subclasses of analytic functions. H. Özlem Güney and Serap Bulut Copyright © 2013 H. Özlem Güney and Serap Bulut. All rights reserved. Wed, 08 May 2013 10:39:20 +0000 http://www.hindawi.com/journals/jmath/2013/609218/ We begin by recalling a group which is an enlargement of the diffeomorphisms on an ordinary manifold. We used this larger group to unify the gravitational and electroweak fields, which are mediated by bosons. Unfortunately, we could not include the neutrinos, because geometrical theories based on an ordinary manifold generally cannot include fermions. Therefore, in this paper, we introduce an analogous group that contains the superdiffeomorphisms on a DeWitt supermanifold as a proper subgroup. Dave Pandres Jr. Copyright © 2013 Dave Pandres Jr. All rights reserved. Tue, 07 May 2013 13:11:43 +0000 http://www.hindawi.com/journals/jmath/2013/793824/ Frame theory is the study of topology based on its open set lattice, and it was studied extensively by various authors. In this paper, we study quotients of intuitionistic fuzzy filters of an intuitionistic fuzzy coframe. The quotients of intuitionistic fuzzy filters are shown to be filters of the given intuitionistic fuzzy coframe. It is shown that the collection of all intuitionistic fuzzy filters of a coframe and the collection of all intutionistic fuzzy quotient filters of an intuitionistic fuzzy filter are coframes. Rajesh K. Thumbakara Copyright © 2013 Rajesh K. Thumbakara. All rights reserved. Thu, 02 May 2013 16:02:29 +0000 http://www.hindawi.com/journals/jmath/2013/457631/ We study a mixed problem with an integral two-space-variables condition for parabolic equation with the Bessel operator. The existence and uniqueness of the solution in functional weighted Sobolev space are proved. The proof is based on a priori estimate “energy inequality” and the density of the range of the operator generated by the problem considered. Bouziani Abdelfatah, Oussaeif Taki-Eddine, and Ben Aoua Leila Copyright © 2013 Bouziani Abdelfatah et al. All rights reserved. Sun, 28 Apr 2013 08:45:55 +0000 http://www.hindawi.com/journals/jmath/2013/645752/ For the famous Darboux-Pöschl-Teller equation, we present new wronskian representation both for the potential and the related eigenfunctions. The simplest application of this new formula is the explicit description of dynamics of the DPT potentials and the action of the KdV hierarchy. The key point of the proof is some evaluation formulas for special wronskian determinant. Pierre Gaillard and Vladimir Matveev Copyright © 2013 Pierre Gaillard and Vladimir Matveev. All rights reserved. Tue, 23 Apr 2013 10:54:43 +0000 http://www.hindawi.com/journals/jmath/2013/146836/ The aim of this paper is to extend the use of homotopy perturbation method (HPM) to study the solutions for some important generalized nonlinear partial differential equations (PDEs) such as Fisher equation with convection term, Sharma-Tasso-Olver (STO) equation, and Fitzhugh-Nagumo (FN) equation. Marwan Alquran, Mahmoud Mohammad, and Ahmad Ababneh Copyright © 2013 Marwan Alquran et al. All rights reserved. Mon, 22 Apr 2013 13:08:39 +0000 http://www.hindawi.com/journals/jmath/2013/630934/ We introduce and study a subclass of analytic functions related to Robertson functions. Here we discuss the coefficient estimate for function in this class. Muhammad Arif and Mumtaz Ali Copyright © 2013 Muhammad Arif and Mumtaz Ali. All rights reserved. Thu, 18 Apr 2013 10:21:16 +0000 http://www.hindawi.com/journals/jmath/2013/920528/ The hyperbolic cosines and sines theorems for the curvilinear triangle bounded by circular arcs of three intersecting circles are formulated and proved by using the general complex calculus. The method is based on a key formula establishing a relationship between exponential function and the cross-ratio. The proofs are carried out on Euclidean plane. Robert M. Yamaleev Copyright © 2013 Robert M. Yamaleev. All rights reserved. Thu, 18 Apr 2013 08:17:29 +0000 http://www.hindawi.com/journals/jmath/2013/650480/ Maji et al. introduced the concept of intuitionistic fuzzy soft sets, which is an extension of soft sets and intuitionistic fuzzy sets. In this paper, we apply the concept of intuitionistic fuzzy soft sets to rings. The concept of intuitionistic fuzzy soft rings is introduced and some basic properties of intuitionistic fuzzy soft rings are given. Intersection, union, AND, and OR operations of intuitionistic fuzzy soft rings are defined. Then, the deffinitions of intuitionistic fuzzy soft ideals are proposed and some related results are considered. B. A. Ersoy, S. Onar, K. Hila, and B. Davvaz Copyright © 2013 B. A. Ersoy et al. All rights reserved. Wed, 17 Apr 2013 08:19:56 +0000 http://www.hindawi.com/journals/jmath/2013/430965/ We have examined the spectra of the operator on the sequence spaces and . Binod Chandra Tripathy and Avinoy Paul Copyright © 2013 Binod Chandra Tripathy and Avinoy Paul. All rights reserved. Tue, 16 Apr 2013 18:49:19 +0000 http://www.hindawi.com/journals/jmath/2013/467351/ Let , and let be an even function. In this paper, we consider some Lagrange interpolation polynomials and the Gauss-Jacobi quadrature formula of entire functions associated with Erdös-type weights , , and we will estimate the error terms. Gou Nakamura, Ryozi Sakai, and Noriaki Suzuki Copyright © 2013 Gou Nakamura et al. All rights reserved. Tue, 16 Apr 2013 13:04:36 +0000 http://www.hindawi.com/journals/jmath/2013/719324/ First we prove common fixed point theorems for weakly compatible maps which generalize the results of Chen (2012). Secondly, we prove common fixed point theorems using property E.A. along with weakly compatible maps. At the end, we prove common fixed point theorems using common limit range property (CLR property) along with weakly compatible maps. Manoj Kumar, Pankaj Kumar, and Sanjay Kumar Copyright © 2013 Manoj Kumar et al. All rights reserved. Tue, 16 Apr 2013 10:52:06 +0000 http://www.hindawi.com/journals/jmath/2013/207176/ We study the inverses of block Toeplitz matrices based on the analysis of the block cyclic displacement. New formulas for the inverses of block Toeplitz matrices are proposed. We show that the inverses of block Toeplitz matrices can be decomposed as a sum of products of block circulant matrices. In the scalar case, the inverse formulas are proved to be numerically forward stable, if the Toeplitz matrix is nonsingular and well conditioned. Xiao-Guang Lv and Ting-Zhu Huang Copyright © 2013 Xiao-Guang Lv and Ting-Zhu Huang. All rights reserved. Tue, 16 Apr 2013 10:14:24 +0000 http://www.hindawi.com/journals/jmath/2013/126347/ The widespread and rapid proliferation of logical systems in several areas of computer science has led to a resurgence of interest in various methods for combining logical systems and in investigations into the properties inherited by the resulting combinations. One of the oldest such methods is fibring. In fibring the shared connectives of the combined logics inherit properties from both component logical systems, and this leads often to inconsistencies. To deal with such undesired effects, Sernadas et al. (2011, 2012) have recently introduced a novel way of combining logics, called meet-combination, in which the combined connectives share only the common logical properties they enjoy in the component systems. In their investigations they provide a sound and concretely complete calculus for the meet-combination based on available sound and complete calculi for the component systems. In this work, an effort is made to abstract those results to a categorical level amenable to categorical abstract algebraic logic techniques. George Voutsadakis Copyright © 2013 George Voutsadakis. All rights reserved. Wed, 10 Apr 2013 09:34:47 +0000 http://www.hindawi.com/journals/jmath/2013/105848/ Certain properties of the S-transform are given and composition of S-transform is defined. We study the fractional S-transform on spaces of type . It is shown that the fractional S-transform is a continuous linear map of the space of type defined on into the space of type defined on . Sunil Kumar Singh Copyright © 2013 Sunil Kumar Singh. All rights reserved. Tue, 09 Apr 2013 13:29:09 +0000 http://www.hindawi.com/journals/jmath/2013/489863/ The aim of this paper is to study magneto-thermoelastic interactions in an initially stressed isotropic homogeneous half-space in the context of fractional order theory of generalized thermoelasticity. State space formulation with the Laplace transform technique is used to obtain the general solution, and the resulting formulation is applied to the ramp type increase in thermal load and zero stress. Solutions of the problem in the physical domain are obtained by using a numerical method of the Laplace inverse transform based on the Fourier expansion technique, and the expressions for the displacement, temperature, and stress inside the half-space are obtained. Numerical computations are carried out for a particular material for illustrating the results. Results obtained for the field variables are displayed graphically. Some comparisons have been shown in figures to present the effect of fractional parameter, ramp parameter, magnetic field, and initial stress on the field variables. Some particular cases of special interest have been deduced from the present investigation. Sunita Deswal, Sandeep Singh Sheoran, and Kapil Kumar Kalkal Copyright © 2013 Sunita Deswal et al. All rights reserved. Tue, 09 Apr 2013 11:44:29 +0000 http://www.hindawi.com/journals/jmath/2013/912643/ Let be a commutative Noetherian local ring and let be a finitely generated -module of dimension . Then the following statements hold: (a) if width for all with , then is co-Cohen-Macaulay of Noetherian dimension ; (b) if is an unmixed -module and depth , then is co-Cohen-Macaulay of Noetherian dimension if and only if is either zero or co-Cohen-Macaulay of Noetherian dimension . As consequence, if is co-Cohen-Macaulay of Noetherian dimension for all with , then is co-Cohen-Macaulay of Noetherian dimension . Hero Saremi and Amir Mafi Copyright © 2013 Hero Saremi and Amir Mafi. All rights reserved. Sun, 07 Apr 2013 16:25:21 +0000 http://www.hindawi.com/journals/jmath/2013/726297/ We study the continuous-time mean-variance portfolio selection problem in the situation when investors must pay margin for short selling. The problem is essentially a nonlinear stochastic optimal control problem because the coefficients of positive and negative parts of control variables are different. We can not apply the results of stochastic linearquadratic (LQ) problem. Also the solution of corresponding Hamilton-Jacobi-Bellman (HJB) equation is not smooth. Li et al. (2002) studied the case when short selling is prohibited; therefore they only need to consider the positive part of control variables, whereas we need to handle both the positive part and the negative part of control variables. The main difficulty is that the positive part and the negative part are not independent. The previous results are not directly applicable. By decomposing the problem into several subproblems we figure out the solutions of HJB equation in two disjoint regions and then prove it is the viscosity solution of HJB equation. Finally we formulate solution of optimal portfolio and the efficient frontier. We also present two examples showing how different margin rates affect the optimal solutions and the efficient frontier. Yuan Zhou and Zhe Wu Copyright © 2013 Yuan Zhou and Zhe Wu. All rights reserved. Wed, 03 Apr 2013 14:14:35 +0000 http://www.hindawi.com/journals/jmath/2013/418546/ Using a generalized translation operator, we obtain an analog of Theorem 5.2 in Younis (1986) for the Bessel transform for functions satisfying the -Bessel Lipschitz condition in . Radouan Daher and Mohamed El Hamma Copyright © 2013 Radouan Daher and Mohamed El Hamma. All rights reserved. Wed, 03 Apr 2013 10:43:08 +0000 http://www.hindawi.com/journals/jmath/2013/936859/ The oblateness and the photogravitational effects of both the primaries on the location and the stability of the triangular equilibrium points in the elliptical restricted three-body problem have been discussed. The stability of the triangular points under the photogravitational and oblateness effects of both the primaries around the binary systems Achird, Lyeten, Alpha Cen-AB, Kruger 60, and Xi-Bootis, has been studied using simulation techniques by drawing different curves of zero velocity. A. Narayan and Amit Shrivastava Copyright © 2013 A. Narayan and Amit Shrivastava. All rights reserved. Wed, 03 Apr 2013 10:34:48 +0000 http://www.hindawi.com/journals/jmath/2013/678946/ We introduce a new implicit random iteration process generated by a finite family of asymptotically quasi-nonexpansive-type mappings and study necessary and sufficient conditions for the convergence of this process in a uniformly convex Banach space. The results presented in this paper extend and improve the recent ones announced by Plubtieng et al. (2007), Beg and Thakur (2009), and Saluja and Nashine (2012). A. S. Saluja and Pankaj kumar Jhade Copyright © 2013 A. S. Saluja and Pankaj kumar Jhade. All rights reserved. Sun, 31 Mar 2013 14:26:30 +0000 http://www.hindawi.com/journals/jmath/2013/181724/ Contour integral representations of Riemann's Zeta function and Dirichlet's Eta (alternating Zeta) function are presented and investigated. These representations flow naturally from methods developed in the 1800s, but somehow they do not appear in the standard reference summaries, textbooks, or literature. Using these representations as a basis, alternate derivations of known series and integral representations for the Zeta and Eta function are obtained on a unified basis that differs from the textbook approach, and results are developed that appear to be new. Michael S. Milgram Copyright © 2013 Michael S. Milgram. All rights reserved. Tue, 26 Mar 2013 12:39:47 +0000 http://www.hindawi.com/journals/jmath/2013/506275/ Recently, Denniston, Melton, and Rodabaugh presented a new categorical outlook on a certain lattice-valued extension of Formal Concept Analysis (FCA) of Ganter and Wille; their outlook was based on the notion of lattice-valued interchange system and a category of Galois connections. This paper extends the approach of Denniston et al. clarifying the relationships between Chu spaces of Pratt, many-valued formal contexts of FCA, lattice-valued interchange systems, and Galois connections. Sergey A. Solovyov Copyright © 2013 Sergey A. Solovyov. All rights reserved. Mon, 25 Mar 2013 11:58:37 +0000 http://www.hindawi.com/journals/jmath/2013/878730/ We prove some common fixed point theorems for -contractions in 0-complete partial metric spaces. Our results extend, generalize, and unify several known results in the literature. Some examples are included which show that the generalization is proper. Satish Shukla and Stojan Radenović Copyright © 2013 Satish Shukla and Stojan Radenović. All rights reserved. Mon, 25 Mar 2013 11:08:13 +0000 http://www.hindawi.com/journals/jmath/2013/592708/ We have characterized right weakly regular semigroups by the properties of their -fuzzy ideals. Madad Khan and Saima Anis Copyright © 2013 Madad Khan and Saima Anis. All rights reserved. Sun, 24 Mar 2013 16:24:18 +0000 http://www.hindawi.com/journals/jmath/2013/370143/ Let be a closed, convex, and nonempty subset of a real -uniformly smooth Banach space , which is also uniformly convex. For some , let and be family of nonexpansive maps and -inverse strongly accretive map, respectively. Let be a bifunction satisfying some conditions. Let be a nonexpansive projection of onto . For some fixed real numbers , , and arbitrary but fixed vectors , let and be sequences generated by , , , , , where is fixed, and are sequences satisfying appropriate conditions. If , under some mild conditions, we prove that the sequences and converge strongly to some element in . Bashir Ali Copyright © 2013 Bashir Ali. All rights reserved.