**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**29

# Search results for: Iterative algorithm

##### 29 An Improved Method to Compute Sparse Graphs for Traveling Salesman Problem

**Authors:**
Y. Wang

**Abstract:**

The Traveling salesman problem (TSP) is NP-hard in combinatorial optimization. The research shows the algorithms for TSP on the sparse graphs have the shorter computation time than those for TSP according to the complete graphs. We present an improved iterative algorithm to compute the sparse graphs for TSP by frequency graphs computed with frequency quadrilaterals. The iterative algorithm is enhanced by adjusting two parameters of the algorithm. The computation time of the algorithm is *O*(*CN*_{max}*n*^{2}) where *C* is the iterations, *N*_{max} is the maximum number of frequency quadrilaterals containing each edge and *n* is the scale of TSP. The experimental results showed the computed sparse graphs generally have less than 5*n* edges for most of these Euclidean instances. Moreover, the maximum degree and minimum degree of the vertices in the sparse graphs do not have much difference. Thus, the computation time of the methods to resolve the TSP on these sparse graphs will be greatly reduced.

**Keywords:**
Frequency quadrilateral,
iterative algorithm,
sparse graph,
traveling salesman problem.

##### 28 Conjugate Mixed Convection Heat Transfer and Entropy Generation of Cu-Water Nanofluid in an Enclosure with Thick Wavy Bottom Wall

**Authors:**
Sanjib Kr Pal,
S. Bhattacharyya

**Abstract:**

**Keywords:**
Entropy generation,
mixed convection,
conjugate heat
transfer,
numerical,
nanofluid,
wall waviness.

##### 27 A Numerical Study on Electrophoresis of a Soft Particle with Charged Core Coated with Polyelectrolyte Layer

**Authors:**
Partha Sarathi Majee,
S. Bhattacharyya

**Abstract:**

**Keywords:**
Debye length,
double layer polarization,
electrophoresis,
mobility reversal,
soft particle.

##### 26 An Efficient Iterative Updating Method for Damped Structural Systems

**Authors:**
Jiashang Jiang

**Abstract:**

Model updating is an inverse eigenvalue problem which concerns the modification of an existing but inaccurate model with measured modal data. In this paper, an efficient gradient based iterative method for updating the mass, damping and stiffness matrices simultaneously using a few of complex measured modal data is developed. Convergence analysis indicates that the iterative solutions always converge to the unique minimum Frobenius norm symmetric solution of the model updating problem by choosing a special kind of initial matrices.

**Keywords:**
Model updating,
iterative algorithm,
damped structural
system,
optimal approximation.

##### 25 New Iterative Algorithm for Improving Depth Resolution in Ionic Analysis: Effect of Iterations Number

**Authors:**
N. Dahraoui,
M. Boulakroune,
D. Benatia

**Abstract:**

In this paper, the improvement by deconvolution of the depth resolution in Secondary Ion Mass Spectrometry (SIMS) analysis is considered. Indeed, we have developed a new Tikhonov- Miller deconvolution algorithm where a priori model of the solution is included. This is a denoisy and pre-deconvoluted signal obtained from: firstly, by the application of wavelet shrinkage algorithm, secondly by the introduction of the obtained denoisy signal in an iterative deconvolution algorithm. In particular, we have focused the light on the effect of the iterations number on the evolution of the deconvoluted signals. The SIMS profiles are multilayers of Boron in Silicon matrix.

**Keywords:**
DRF,
in-depth resolution,
multiresolution
deconvolution,
SIMS,
wavelet shrinkage.

##### 24 Effect of Iterative Algorithm on the Performance of MC-CDMA System with Nonlinear Models of HPA

**Authors:**
R. Blicha

**Abstract:**

High Peak to Average Power Ratio (PAPR) of the transmitted signal is a serious problem in multicarrier systems (MC), such as Orthogonal Frequency Division Multiplexing (OFDM), or in Multi-Carrier Code Division Multiple Access (MC-CDMA) systems, due to large number of subcarriers. This effect is possible reduce with some PAPR reduction techniques. Spreading sequences at the presence of Saleh and Rapp models of high power amplifier (HPA) have big influence on the behavior of system. In this paper we investigate the bit-error-rate (BER) performance of MC-CDMA systems. Basically we can see from simulations that the MC-CDMA system with Iterative algorithm can be providing significantly better results than the MC-CDMA system. The results of our analyses are verified via simulation.

**Keywords:**
MC-CDMA,
Iterative algorithm,
PAPR,
BER,
Saleh,
Rapp,
Spreading Sequences.

##### 23 Approximating Fixed Points by a Two-Step Iterative Algorithm

**Authors:**
Safeer Hussain Khan

**Abstract:**

In this paper, we introduce a two-step iterative algorithm to prove a strong convergence result for approximating common fixed points of three contractive-like operators. Our algorithm basically generalizes an existing algorithm..Our iterative algorithm also contains two famous iterative algorithms: Mann iterative algorithm and Ishikawa iterative algorithm. Thus our result generalizes the corresponding results proved for the above three iterative algorithms to a class of more general operators. At the end, we remark that nothing prevents us to extend our result to the case of the iterative algorithm with error terms.

**Keywords:**
Contractive-like operator,
iterative algorithm,
fixed point,
strong convergence.

##### 22 A New Inversion-free Method for Hermitian Positive Definite Solution of Matrix Equation

**Authors:**
Minghui Wang,
Juntao Zhang

**Abstract:**

An inversion-free iterative algorithm is presented for solving nonlinear matrix equation with a stepsize parameter t. The existence of the maximal solution is discussed in detail, and the method for finding it is proposed. Finally, two numerical examples are reported that show the efficiency of the method.

**Keywords:**
Inversion-free method,
Hermitian positive definite solution,
Maximal solution,
Convergence.

##### 21 An Iterative Method for Quaternionic Linear Equations

**Authors:**
Bin Yu,
Minghui Wang,
Juntao Zhang

**Abstract:**

By the real representation of the quaternionic matrix, an iterative method for quaternionic linear equations Ax = b is proposed. Then the convergence conditions are obtained. At last, a numerical example is given to illustrate the efficiency of this method.

**Keywords:**
Quaternionic linear equations,
Real representation,
Iterative algorithm.

##### 20 Accuracy of Displacement Estimation and Selection of Capacitors for a Four Degrees of Freedom Capacitive Force Sensor

**Authors:**
Chisato Murakami,
Makoto Takahashi

**Abstract:**

Force sensor has been used as requisite for knowing information on the amount and the directions of forces on the skin surface. We have developed a four-degrees-of-freedom capacitive force sensor (approximately 20×20×5 mm^{3}) that has a flexible structure and sixteen parallel plate capacitors. An iterative algorithm was developed for estimating four displacements from the sixteen capacitances using fourth-order polynomial approximation of characteristics between capacitance and displacement. The estimation results from measured capacitances had large error caused by deterioration of the characteristics. In this study, effective capacitors had major information were selected on the basis of the capacitance change range and the characteristic shape. Maximum errors in calibration and non-calibration points were 25%and 6.8%.However the maximum error was larger than desired value, the smallness of averaged value indicated the occurrence of a few large error points. On the other hand, error in non-calibration point was within desired value.

**Keywords:**
Force sensors,
capacitive sensors,
estimation,
iterative algorithms.

##### 19 Two Iterative Algorithms to Compute the Bisymmetric Solution of the Matrix Equation A1X1B1 + A2X2B2 + ... + AlXlBl = C

**Authors:**
A.Tajaddini

**Abstract:**

In this paper, two matrix iterative methods are presented to solve the matrix equation A1X1B1 + A2X2B2 + ... + AlXlBl = C the minimum residual problem l i=1 AiXiBi−CF = minXi∈BRni×ni l i=1 AiXiBi−CF and the matrix nearness problem [X1, X2, ..., Xl] = min[X1,X2,...,Xl]∈SE [X1,X2, ...,Xl] − [X1, X2, ..., Xl]F , where BRni×ni is the set of bisymmetric matrices, and SE is the solution set of above matrix equation or minimum residual problem. These matrix iterative methods have faster convergence rate and higher accuracy than former methods. Paige’s algorithms are used as the frame method for deriving these matrix iterative methods. The numerical example is used to illustrate the efficiency of these new methods.

**Keywords:**
Bisymmetric matrices,
Paige’s algorithms,
Least
square.

##### 18 Preconditioned Jacobi Method for Fuzzy Linear Systems

**Authors:**
Lina Yan,
Shiheng Wang,
Ke Wang

**Abstract:**

A preconditioned Jacobi (PJ) method is provided for solving fuzzy linear systems whose coefficient matrices are crisp Mmatrices and the right-hand side columns are arbitrary fuzzy number vectors. The iterative algorithm is given for the preconditioned Jacobi method. The convergence is analyzed with convergence theorems. Numerical examples are given to illustrate the procedure and show the effectiveness and efficiency of the method.

**Keywords:**
preconditioning,
M-matrix,
Jacobi method,
fuzzy linear
system (FLS).

##### 17 An Iterative Algorithm for Inverse Kinematics of 5-DOF Manipulator with Offset Wrist

**Authors:**
Juyi Park,
Jung-Min Kim,
Hee-Hwan Park,
Jin-Wook Kim,
Gye-Hyung Kang,
Soo-Ho Kim

**Abstract:**

**Keywords:**
5-DOF manipulator,
Inverse kinematics,
Iterative
algorithm,
Wrist offset.

##### 16 Automated Stereophotogrammetry Data Cleansing

**Authors:**
Stuart Henry,
Philip Morrow,
John Winder,
Bryan Scotney

**Abstract:**

The stereophotogrammetry modality is gaining more widespread use in the clinical setting. Registration and visualization of this data, in conjunction with conventional 3D volumetric image modalities, provides virtual human data with textured soft tissue and internal anatomical and structural information. In this investigation computed tomography (CT) and stereophotogrammetry data is acquired from 4 anatomical phantoms and registered using the trimmed iterative closest point (TrICP) algorithm. This paper fully addresses the issue of imaging artifacts around the stereophotogrammetry surface edge using the registered CT data as a reference. Several iterative algorithms are implemented to automatically identify and remove stereophotogrammetry surface edge outliers, improving the overall visualization of the combined stereophotogrammetry and CT data. This paper shows that outliers at the surface edge of stereophotogrammetry data can be successfully removed automatically.

**Keywords:**
Data cleansing,
stereophotogrammetry.

##### 15 An Iterative Algorithm to Compute the Generalized Inverse A(2) T,S Under the Restricted Inner Product

**Authors:**
Xingping Sheng

**Abstract:**

**Keywords:**
Generalized inverse A(2)
T,
S,
Restricted inner product,
Iterative method,
Orthogonal projection.

##### 14 A Numerical Approach for Static and Dynamic Analysis of Deformable Journal Bearings

**Authors:**
D. Benasciutti,
M. Gallina,
M. Gh. Munteanu,
F. Flumian

**Abstract:**

**Keywords:**
Journal bearing,
finite elements,
deformation,
dynamic analysis

##### 13 Experimental Results about the Dynamics of the Generalized Belief Propagation Used on LDPC Codes

**Authors:**
Jean-Christophe Sibel,
Sylvain Reynal,
David Declercq

**Abstract:**

In the context of channel coding, the Generalized Belief Propagation (GBP) is an iterative algorithm used to recover the transmission bits sent through a noisy channel. To ensure a reliable transmission, we apply a map on the bits, that is called a code. This code induces artificial correlations between the bits to send, and it can be modeled by a graph whose nodes are the bits and the edges are the correlations. This graph, called Tanner graph, is used for most of the decoding algorithms like Belief Propagation or Gallager-B. The GBP is based on a non unic transformation of the Tanner graph into a so called region-graph. A clear advantage of the GBP over the other algorithms is the freedom in the construction of this graph. In this article, we explain a particular construction for specific graph topologies that involves relevant performance of the GBP. Moreover, we investigate the behavior of the GBP considered as a dynamic system in order to understand the way it evolves in terms of the time and in terms of the noise power of the channel. To this end we make use of classical measures and we introduce a new measure called the hyperspheres method that enables to know the size of the attractors.

**Keywords:**
iterative decoder,
LDPC,
region-graph,
chaos.

##### 12 Iterative solutions to the linear matrix equation AXB + CXTD = E

**Authors:**
Yongxin Yuan,
Jiashang Jiang

**Abstract:**

**Keywords:**
matrix equation,
iterative algorithm,
parameter estimation,
minimum norm solution.

##### 11 Iterative Solutions to Some Linear Matrix Equations

**Authors:**
Jiashang Jiang,
Hao Liu,
Yongxin Yuan

**Abstract:**

In this paper the gradient based iterative algorithms are presented to solve the following four types linear matrix equations: (a) AXB = F; (b) AXB = F, CXD = G; (c) AXB = F s. t. X = XT ; (d) AXB+CYD = F, where X and Y are unknown matrices, A,B,C,D, F,G are the given constant matrices. It is proved that if the equation considered has a solution, then the unique minimum norm solution can be obtained by choosing a special kind of initial matrices. The numerical results show that the proposed method is reliable and attractive.

**Keywords:**
Matrix equation,
iterative algorithm,
parameter estimation,
minimum norm solution.

##### 10 Alternative Convergence Analysis for a Kind of Singularly Perturbed Boundary Value Problems

**Authors:**
Jiming Yang

**Abstract:**

A kind of singularly perturbed boundary value problems is under consideration. In order to obtain its approximation, simple upwind difference discretization is applied. We use a moving mesh iterative algorithm based on equi-distributing of the arc-length function of the current computed piecewise linear solution. First, a maximum norm a posteriori error estimate on an arbitrary mesh is derived using a different method from the one carried out by Chen [Advances in Computational Mathematics, 24(1-4) (2006), 197-212.]. Then, basing on the properties of discrete Green-s function and the presented posteriori error estimate, we theoretically prove that the discrete solutions computed by the algorithm are first-order uniformly convergent with respect to the perturbation parameter ε.

**Keywords:**
Convergence analysis,
green's function,
singularly perturbed,
equi-distribution,
moving mesh.

##### 9 An Iterative Updating Method for Damped Gyroscopic Systems

**Authors:**
Yongxin Yuan

**Abstract:**

The problem of updating damped gyroscopic systems using measured modal data can be mathematically formulated as following two problems. Problem I: Given Ma ∈ Rn×n, Λ = diag{λ1, ··· , λp} ∈ Cp×p, X = [x1, ··· , xp] ∈ Cn×p, where p<n and both Λ and X are closed under complex conjugation in the sense that λ2j = λ¯2j−1 ∈ C, x2j = ¯x2j−1 ∈ Cn for j = 1, ··· , l, and λk ∈ R, xk ∈ Rn for k = 2l + 1, ··· , p, find real-valued symmetric matrices D,K and a real-valued skew-symmetric matrix G (that is, GT = −G) such that MaXΛ2 + (D + G)XΛ + KX = 0. Problem II: Given real-valued symmetric matrices Da, Ka ∈ Rn×n and a real-valued skew-symmetric matrix Ga, find (D, ˆ G, ˆ Kˆ ) ∈ SE such that Dˆ −Da2+Gˆ−Ga2+Kˆ −Ka2 = min(D,G,K)∈SE (D− Da2 + G − Ga2 + K − Ka2), where SE is the solution set of Problem I and · is the Frobenius norm. This paper presents an iterative algorithm to solve Problem I and Problem II. By using the proposed iterative method, a solution of Problem I can be obtained within finite iteration steps in the absence of roundoff errors, and the minimum Frobenius norm solution of Problem I can be obtained by choosing a special kind of initial matrices. Moreover, the optimal approximation solution (D, ˆ G, ˆ Kˆ ) of Problem II can be obtained by finding the minimum Frobenius norm solution of a changed Problem I. A numerical example shows that the introduced iterative algorithm is quite efficient.

**Keywords:**
Model updating,
iterative algorithm,
gyroscopic system,
partially prescribed spectral data,
optimal approximation.

##### 8 Accurate Visualization of Graphs of Functions of Two Real Variables

**Authors:**
Zeitoun D. G.,
Thierry Dana-Picard

**Abstract:**

The study of a real function of two real variables can be supported by visualization using a Computer Algebra System (CAS). One type of constraints of the system is due to the algorithms implemented, yielding continuous approximations of the given function by interpolation. This often masks discontinuities of the function and can provide strange plots, not compatible with the mathematics. In recent years, point based geometry has gained increasing attention as an alternative surface representation, both for efficient rendering and for flexible geometry processing of complex surfaces. In this paper we present different artifacts created by mesh surfaces near discontinuities and propose a point based method that controls and reduces these artifacts. A least squares penalty method for an automatic generation of the mesh that controls the behavior of the chosen function is presented. The special feature of this method is the ability to improve the accuracy of the surface visualization near a set of interior points where the function may be discontinuous. The present method is formulated as a minimax problem and the non uniform mesh is generated using an iterative algorithm. Results show that for large poorly conditioned matrices, the new algorithm gives more accurate results than the classical preconditioned conjugate algorithm.

**Keywords:**
Function singularities,
mesh generation,
point allocation,
visualization,
collocation least squares method,
Augmented Lagrangian method,
Uzawa's Algorithm,
Preconditioned Conjugate Gradien

##### 7 Code-Aided Turbo Channel Estimation for OFDM Systems with NB-LDPC Codes

**Authors:**
Ł. Januszkiewicz,
G. Bacci,
H. Gierszal,
M. Luise

**Abstract:**

**Keywords:**
LDPC codes,
LMMSE,
OFDM,
turbo channelestimation.

##### 6 An Iterative Method for the Least-squares Symmetric Solution of AXB+CYD=F and its Application

**Authors:**
Minghui Wang

**Abstract:**

Based on the classical algorithm LSQR for solving (unconstrained) LS problem, an iterative method is proposed for the least-squares like-minimum-norm symmetric solution of AXB+CYD=E. As the application of this algorithm, an iterative method for the least-squares like-minimum-norm biymmetric solution of AXB=E is also obtained. Numerical results are reported that show the efficiency of the proposed methods.

**Keywords:**
Matrix equation,
bisymmetric matrix,
least squares problem,
like-minimum norm,
iterative algorithm.

##### 5 Determination of Sequential Best Replies in N-player Games by Genetic Algorithms

**Authors:**
Mattheos K. Protopapas,
Elias B. Kosmatopoulos

**Abstract:**

An iterative algorithm is proposed and tested in Cournot Game models, which is based on the convergence of sequential best responses and the utilization of a genetic algorithm for determining each player-s best response to a given strategy profile of its opponents. An extra outer loop is used, to address the problem of finite accuracy, which is inherent in genetic algorithms, since the set of feasible values in such an algorithm is finite. The algorithm is tested in five Cournot models, three of which have convergent best replies sequence, one with divergent sequential best replies and one with “local NE traps"[14], where classical local search algorithms fail to identify the Nash Equilibrium. After a series of simulations, we conclude that the algorithm proposed converges to the Nash Equilibrium, with any level of accuracy needed, in all but the case where the sequential best replies process diverges.

**Keywords:**
Best response,
Cournot oligopoly,
genetic algorithms,
Nash equilibrium.

##### 4 BIDENS: Iterative Density Based Biclustering Algorithm With Application to Gene Expression Analysis

**Authors:**
Mohamed A. Mahfouz,
M. A. Ismail

**Abstract:**

**Keywords:**
Machine learning,
biclustering,
bi-dimensional
clustering,
gene expression analysis,
data mining.

##### 3 The Riemann Barycenter Computation and Means of Several Matrices

**Authors:**
Miklos Palfia

**Abstract:**

An iterative definition of any n variable mean function is given in this article, which iteratively uses the two-variable form of the corresponding two-variable mean function. This extension method omits recursivity which is an important improvement compared with certain recursive formulas given before by Ando-Li-Mathias, Petz- Temesi. Furthermore it is conjectured here that this iterative algorithm coincides with the solution of the Riemann centroid minimization problem. Certain simulations are given here to compare the convergence rate of the different algorithms given in the literature. These algorithms will be the gradient and the Newton mehod for the Riemann centroid computation.

**Keywords:**
Means,
matrix means,
operator means,
geometric mean,
Riemannian center of mass.

##### 2 Contour Estimation in Synthetic and Real Weld Defect Images based on Maximum Likelihood

**Authors:**
M. Tridi,
N. Nacereddine,
N. Oucief

**Abstract:**

**Keywords:**
Contour,
gaussian,
likelihood,
rayleigh.

##### 1 An Iterative Algorithm for KLDA Classifier

**Authors:**
D.N. Zheng,
J.X. Wang,
Y.N. Zhao,
Z.H. Yang

**Abstract:**

**Keywords:**
Linear discriminant analysis (LDA),
kernel LDA
(KLDA),
conjugate gradient algorithm,
nonlinear discriminant classifier.