Authors:Vejdi I. Hasanov; Aynur A. Ali Pages: 79 - 87 Abstract: In this paper, we give new convergence results for the basic fixed point iteration and its two inversion-free variants for finding the maximal positive definite solution of the matrix equation \(X+A^{*}X^{-1}A+B^{*}X^{-1}B=Q\) , proposed by Long et al. (Bull Braz Math Soc 39:371–386, 2008) and Vaezzadeh et al. (Adv Differ Equ 2013). The new results are illustrated by numerical examples. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0215-6 Issue No:Vol. 36, No. 1 (2017)

Authors:A. Brillard; J. F. Brilhac; M. Valente Pages: 89 - 109 Abstract: The pyrolysis and the combustion processes of grape marc samples are evaluated experimentally through a thermogravimetry analysis, which leads to curves indicating the variations of the overall mass of the sample and of the mass loss rate. An extended independent parallel reaction model (EIPR) based on the biomass lignocellulosic representation is proposed to simulate the thermal decomposition of the grape marc considering both the devolatilization and the char combustion steps. The set of the best kinetic parameters of this EIPR model is determined through a numerical procedure based on the SCILAB software and comparing the experimental and the computed curves. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0216-5 Issue No:Vol. 36, No. 1 (2017)

Authors:Sang-Eon Han Pages: 127 - 144 Abstract: To digitize subspaces of the Euclidean \(n\) D space, the present paper uses the Khalimsky (for short \(K\) -, if there is no danger of ambiguity) topology, \(K\) -adjacency and \(K\) -localized neighborhoods of points in \(\mathbf{Z}^n\) , where \(\mathbf{Z}^n\) represents the set of points in the Euclidean \(n\) D space with integer coordinates. Namely, given a point \(p \in \mathbf{Z}^n\) , the paper first develops a \(K\) -localized neighborhood of \(p \in \mathbf{Z}^n\) , denoted by \(N_K(p)\) in \(\mathbf{R}^n\) , which is substantially used in digitizing subspaces of the Euclidean \(n\) D space. The recent paper Han and Sostak in (Comput Appl Math 32(3):521–536, 2013) proposes a connectedness preserving map (for short CP-map, e.g., an \(A\) -map in this paper) which need not be a continuous map under \(K\) -topology and further, develops a certain CP-isomorphism, e.g., an \(A\) -isomorphism in this paper. It turns out that an \(A\) -map overcomes some limitations of both a \(K\) -continuous map and a Khalimsky adjacency map (for brevity \(KA\) -map) so that both an \(A\) -map and an \(A\) -isomorphism can substantially contribute to applied topology including both digital topology and digital geometry Han and Sostak in (Comput Appl Math 32(3):521–536, 2013). Using both an \(A\) -map and a \(K\) -localized neighborhood, we further develop the notions of a lattice-based \(A\) -map (for short \(LA\) -map) and a lattice-based \(A\) -isomorphism (for brevity \(LA\) -isomorphism) which are used for digitizing subspaces of the Euclidean \(n\)... PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0223-6 Issue No:Vol. 36, No. 1 (2017)

Authors:M. Pirhaji; H. Mansouri; M. Zangiabadi Pages: 145 - 157 Abstract: In this paper, we propose a primal–dual interior-point method for semidefinite optimization problems. The algorithm is based on a new class of search directions and the Ai-Zhang’s wide neighborhood for monotone linear complementarity problems. The theoretical complexity of the new algorithm is calculated. It is investigated that the proposed algorithm has polynomial iteration complexity \(O(\sqrt{n}L)\) and coincides with the best known iteration bound for semidefinite optimization problems. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0220-9 Issue No:Vol. 36, No. 1 (2017)

Authors:Vahid Kayvanfar; M. Zandieh; Ehsan Teymourian Pages: 159 - 184 Abstract: Identical parallel machine scheduling problem with controllable processing times is investigated in this research. In such an area, our focus is mostly motivated by the adoption of just-in-time (JIT) philosophy with the objective of minimizing total weighted tardiness and earliness as well as job compressions/expansion cost simultaneously. Also the optimal set amounts of job compressions/expansion plus the job sequence are determined on each machine. It is assumed that the jobs processing times can vary within a given interval, i.e., it is permitted to compress or expand in return for compression/expansion cost. A mixed integer linear programming (MILP) model for the considered problem is firstly proposed and thereafter the optimal jobs set amounts of compression and expansion processing times in a known sequence are determined via parallel net benefit compression–net benefit expansion called PNBC–NBE heuristic. An intelligent water drop (IWD) algorithm, as a new swarm-based nature-inspired optimization one, is also adopted to solve this multi-criteria problem. A heuristic method besides three meta-heuristic algorithms is then employed to solve small- and medium- to large-size sample-generated instances. Computational results reveal that the proposed IWDNN outperforms the other techniques and is a trustable one which can solve such complicated problems with satisfactory consequences. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0218-3 Issue No:Vol. 36, No. 1 (2017)

Authors:Yigui Ou; Yuanwen Liu Pages: 259 - 279 Abstract: This paper presents two new supermemory gradient algorithms for solving convex-constrained nonlinear monotone equations, which combine the idea of supermemory gradient method with the projection method. The feature of these proposed methods is that at each iteration, they do not require the Jacobian information and solve any subproblem, even if they do not store any matrix. Thus, they are suitable for solving large-scale equations. Under mild conditions, the proposed methods are shown to be globally convergent. Preliminary numerical results show that the proposed methods are efficient and can be applied to solve large-scale nonsmooth equations. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0228-1 Issue No:Vol. 36, No. 1 (2017)

Authors:Yifen Ke; Changfeng Ma Pages: 359 - 365 Abstract: In this paper, an alternating direction method (ADM) is proposed for nonnegative solutions of the matrix equation \(AX+YB=C\) . In addition, the preliminary convergence of the proposed method is given and proved. Numerical experiments illustrate the effectiveness of the method. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0232-5 Issue No:Vol. 36, No. 1 (2017)

Authors:Fuqing Zhao; Zhongshi Shao; Junbiao Wang; Chuck Zhang Pages: 433 - 458 Abstract: Estimation of distribution algorithms (EDAs) and differential evolution (DE) are two types of evolutionary algorithms. The former has fast convergence rate and strong global search capability, but is easily trapped in local optimum. The latter has good local search capability with slower convergence speed. Therefore, a new hybrid optimization algorithm which combines the merits of both algorithms, a hybrid optimization algorithm based on chaotic differential evolution and estimation of distribution (cDE/EDA) was proposed. Due to its effective nature of harmonizing the global search of EDA with the local search of DE, the proposed algorithm can discover the optimal solution in a fast and reliable manner. Chaotic policy was used to strengthen the search ability of DE. Meantime the global convergence of algorithm was analyzed with the aid of limit theorem of monotone bounded sequence. The proposed algorithm was tested through a set of typical benchmark problems. The results demonstrate the effectiveness and efficiency of the proposed cDE/EDA algorithm. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0237-0 Issue No:Vol. 36, No. 1 (2017)

Authors:Federica Di Michele; Pierangelo Marcati; Bruno Rubino Pages: 459 - 479 Abstract: We derive rigorously a set of boundary conditions for heterogenous devices using a description via the quantum hydrodynamic system provided by the Madelung transformations. In particular, we show that the generalized enthalpy should be constant at the interface between classical and quantum domains. This condition provides a set of boundary conditions, which we use to prove the existence and the uniqueness of regular steady solutions of the quantum hydrodynamic system. Finally, we analyse the linear stability of the system supplied with our boundary conditions and we test numerically our model on a toy device. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0235-2 Issue No:Vol. 36, No. 1 (2017)

Authors:M. Hached Pages: 561 - 570 Abstract: In this paper, we introduce a modernized and improved version of the Davison–Man method for the numerical resolution of Sylvester matrix equations. In the case of moderate size problems, we give some background facts about this iterative method, addressing the problem of stagnation and we propose an iterative refinement technique to improve its accuracy. Although not designed to solve large-scale Sylvester equations, we propose an approach combining the extended block Krylov algorithm and the Davison–Man method which gives interesting results in terms of accuracy and shows to be competitive with the classical Krylov subspaces methods. Numerical examples are given to illustrate the efficiency of this approach. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0244-1 Issue No:Vol. 36, No. 1 (2017)

Authors:R. Cancelliere; R. Deluca; M. Gai; P. Gallinari; L. Rubini Pages: 599 - 609 Abstract: Some novel strategies have recently been proposed for single hidden layer neural network training that set randomly the weights from input to hidden layer, while weights from hidden to output layer are analytically determined by pseudoinversion. These techniques are gaining popularity in spite of their known numerical issues when singular and/or almost singular matrices are involved. In this paper, we discuss a critical use of Singular Value Analysis for identification of these drawbacks and we propose an original use of regularisation to determine the output weights, based on the concept of critical hidden layer size. This approach also allows to limit the training computational effort. Besides, we introduce a novel technique which relies an effective determination of input weights to the hidden layer dimension. This approach is tested for both regression and classification tasks, resulting in a significant performance improvement with respect to alternative methods. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0246-z Issue No:Vol. 36, No. 1 (2017)

Authors:M. Heydari; G. B. Loghmani; S. M. Hosseini Pages: 647 - 675 Abstract: In this study, an effective collocation method using new weighted orthogonal basis functions on the half-line, namely the exponential Bernstein functions, is proposed for simulating the solution of the heat transfer of a micropolar fluid through a porous medium with radiation. The governing equations and their associated boundary conditions can be written as a system of nonlinear ordinary differential equations. The presented approach does not require truncating or transforming the semi-infinite domain of the problem to a finite domain. In addition, this method reduces the solution of the problem to the solution of a system of algebraic equations. The effects of the coupling constant, radiation parameter and the permeability parameter on velocity and temperature profiles will be discussed in detail and shown graphically. A comparative study with the previous results of viscous fluid in the literature is made. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0251-2 Issue No:Vol. 36, No. 1 (2017)

Authors:Zhao Yuxin; Li Shenghong; Jin Feng Pages: 749 - 768 Abstract: Community structure is an important topological property of complex networks, which has great significance for understanding the function and organization of networks. Generally, community detection can be formulated as a single-objective or multi-objective optimization problem. Most existing optimization-based community detection algorithms are only applicable to disjoint community structure. However, it has been shown that in most real-world networks, a node may belong to multiple communities implying overlapping community structure. In this paper, we propose a multi-objective evolutionary algorithm for identifying overlapping community structure in complex networks based on the framework of non-dominated sorting genetic algorithm. Two negatively correlated evaluation metrics of community structure, termed as negative fitness sum and unfitness sum, are adopted as the optimization objectives. In our algorithm, link-based adjacency representation of overlapping community structure and a population initialization method based on local expansion are proposed. Extensive experimental results on both synthetic and real-world networks demonstrate that the proposed algorithm is effective and promising in detecting overlapping community structure in complex networks. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0260-1 Issue No:Vol. 36, No. 1 (2017)

Authors:Z. Saeidian; M. Reza Peyghami; M. Habibi; S. Ghasemi Pages: 769 - 790 Abstract: In this paper, we propose a new trust-region method for solving nonlinear systems of equalities and inequalities. The algorithm combines both standard and adaptive trust-region frameworks to construct the steps of the algorithm. The trust-region subproblem is solved in the first iteration using a given initial radius. Then, in each iteration, the standard trust-region method is followed whenever the current trial step is accepted, otherwise, the subproblem is resolved using an adaptive scheme. The convergence results for the new proposed algorithm are established under some mild and standard assumptions. Numerical results on some least-squares test problems show the efficiency and effectiveness of the proposed algorithm in practice too. PubDate: 2017-03-01 DOI: 10.1007/s40314-015-0257-9 Issue No:Vol. 36, No. 1 (2017)

Authors:G. D. Reddy Abstract: The well-known approach to solve the ill-posed problem is Tikhonov regularization scheme. But, the approximate solution of Tikhonov scheme may not contain all the details of the exact solution. To circumference this problem, weighted Tikhonov regularization has been introduced. In this article, we propose two a posteriori parameter choice rules to choose the regularization parameter for weighted Tikhonov regularization and establish the optimal rate of convergence \(O(\delta ^\frac{\alpha +1}{\alpha +2})\) for the scheme based on these proposed rules. The numerical results are documented to demonstrate the significance of the theoretical results. PubDate: 2017-03-21 DOI: 10.1007/s40314-017-0433-1

Authors:Ashvinkumar Chaudhari; Ville Vuorinen; Jari Hämäläinen; Antti Hellsten Abstract: Development and validation of large-eddy simulation (LES) framework to study atmospheric boundary layer flows over complex terrains is reported here. The LES model uses the fourth-order time-accurate Runge–Kutta scheme and a fractional step method. The inflow boundary conditions are generated by using the so-called recycling (or mapping) technique. Evaluation of potential in-land wind park locations is the main application of the validated model. In this work, LES are carried out for turbulent boundary-layer flows over both simple and complex hill geometries. The prediction of the flow separation and reattachment length for a steeper wind-tunnel hill was closer to the measurements than previous numerical studies reported by other authors for the same hill geometry. For the complex hill case, the LES model showed good agreement with full-scale measurements. PubDate: 2017-03-20 DOI: 10.1007/s40314-017-0435-z

Authors:Leonardo A. Poveda; Juan Galvis; Victor M. Calo Abstract: We solve elliptic systems of equations posed on highly heterogeneous materials. Examples of this class of problems are composite structures and geological processes. We focus on a model problem which is a second-order elliptic equation with discontinuous coefficients. These coefficients represent the conductivity of a composite material. We assume a background with a low conductivity that contains inclusions with different thermal properties. Under this scenario, we design a multiscale finite element method to efficiently approximate solutions. The method is based on an asymptotic expansion of the solution in terms of the ratio between the conductivities. The resulting method constructs (locally) finite element basis functions (one for each inclusion). These bases generate the multiscale finite element space where the approximation of the solution is computed. Numerical experiments show the good performance of the proposed methodology. PubDate: 2017-03-20 DOI: 10.1007/s40314-017-0431-3

Authors:N. Barghi Oskouie; G. Hojjati; A. Abdi Abstract: We describe the construction of explicit Nordsieck sequential second derivative general linear methods with a large region of absolute stability. The constructed methods are of order \(p=q=s\) , where q and s are the stage order and the number of internal stages, respectively. To compare, we also construct methods in this class which possess Runge–Kutta stability property. Implementation of the constructed methods in a variable stepsize mode is discussed and efficiency of these methods is verified by some numerical experiments in fixed and variable stepsize environment. PubDate: 2017-03-20 DOI: 10.1007/s40314-017-0436-y

Authors:V. Sireesha; N. Ravi Shankar Abstract: It is often that both less technically trained and some technically trained people find the computation of fuzzy times and floats non intuitive and experience difficulties in understanding the same within a reasonable time. Moreover, for many projects team members frequently update the time estimates to complete the project on schedule; therefore, the earliest and latest times of activities should be determined from time to time. In this paper, an alternative method based on node-weighted rooted tree to compute the project characteristics of a fuzzy project network is proposed. The relation between total float and path float is established. The proposed method is illustrated by taking a numerical example and the practicability of the method is verified by comparing with existing methods. The comparisons revealed that the proposed method is straightforward and effective in finding project characteristics with relatively less computational burden. PubDate: 2017-03-18 DOI: 10.1007/s40314-017-0434-0

Authors:Yi-Fen Ke; Chang-Feng Ma Abstract: A preconditioner is proposed for the large and sparse linear saddle point problems, which is based on a low-order three-by-three block saddle point form. The eigenvalue distribution and an upper bound of the degree of the minimal polynomial for the preconditioned matrix are discussed. Numerical results show that the optimal convergence behavior can be achieved when the new preconditioner is used to accelerate the convergence rate of Krylov subspace methods such as GMRES. PubDate: 2017-03-09 DOI: 10.1007/s40314-017-0432-2