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Recursion is one of the most difficult programming topics for students. In this paper, an instructional method is proposed to enhance students' understanding of recursion tracing. The proposal is based on the use of rules to translate linear recursion algorithms into equivalent, iterative ones. The paper has two main contributions: the instructional method itself, and its evaluation, which is based on previous works of other authors on mental models of recursion. As a result, an enhancement was measured in the viability of mental models exhibited by students (both for linear and multiple recursion), but no significant improvement was detected in their skills for designing recursive algorithms. Evidence was also obtained of the fact that many students with (relatively) viable mental models for linear recursion have unviable mental models for multiple recursion. Finally, it was noticed that many students adopt inaccurate mental models if those models are adequate to handle the given algorithm. [ABSTRACT FROM PUBLISHER]

This paper is concerned with the existence of positive solutions to nonlinear q-fractional differential equations yielding to the integral boundary value conditions. Under sufficient conditions of the nonlinearity, by using some iterative techniques, we get that this problem has two positive solutions and a unique positive solution respectively. Our results improve some recent work. [ABSTRACT FROM AUTHOR]

The proposed chord-fractal pattern has a significant impact on IC capacitor, increasing the capacitance within a limited chip area. To reduce the device area, this paper presents a modified fractal algorithm. This proposed algorithm uses various initiators to perform chord iteration on the unit cell. The iteration procedure automatically generates an area-saving fractal layout of IC capacitor. To verify the proposed algorithm, an area-saving device of chord-fractal is fabricated using UMC 0.18- \mu \textm CMOS technology. [ABSTRACT FROM PUBLISHER]

In this paper, we investigate the semi-analytical solution of Kaup-Kupershmidt equations with the help of a modified method known as the new iteration transformation technique. This method combines the Yang transform and the new iteration technique. The nonlinear terms can be calculated straightforwardly by a new iteration method. The numerical simulation results have been presented to demonstrate the reliability and validity of the proposed approach. The result confirms that the suggested technique is the best tool for dealing with any nonlinear problems arising in technology and science. In addition, in terms of figures for varying fractional order, the physical behavior of new iteration transformation technique solutions has been shown and the numerical simulation is also exhibited. The solutions of the new iteration transformation technique reveal that the projected technique is reliable, competitive and powerful for studying complex nonlinear fractional type models. [ABSTRACT FROM AUTHOR]

Many real-life problems using mathematical modeling can be reduced to scalar and system of nonlinear equations. In this paper, we develop a family of three-step sixth-order method for solving nonlinear equations by employing weight functions in the second and third step of the scheme. Furthermore, we extend this family to the multidimensional case preserving the same order of convergence. Moreover, we have made numerical comparisons with the efficient methods of this domain to verify the suitability of our method. [ABSTRACT FROM AUTHOR]

This paper develops a generalized admittance matrix approach in Fortescue coordinate system to solve unbalanced/unsymmetrical distribution networks including different number of phases. This generalized Fortescue \pi equivalent is defined in this paper for solving the heterogeneous phase, and thus Fortescue, network model. The performance of the approach is demonstrated in different model networks with number of nodes ranging between 168 and 14200. It is found that the current iteration method exploiting the decoupling in admittance matrix in Fortescue coordinate is substantially faster than the typical unbalanced three-phase solution in phase domain. The method has a significant potential for application in real time active power network management. [ABSTRACT FROM PUBLISHER]

A new compact microwave amplifier structure using an iterative technique based on the wave concept iterative procedure (WCIP) is presented. This new multilayer structure is composed of five planar interfaces of strip lines. The technique used to model this structure provides a mixed resolution in modal and spatial domain. By taking the best advantage of each resolution domain, a lower computing time is obtained. The purpose of this paper is to demonstrate that a near field amplification technique is achievable and the WCIP is suitable to electromagnetic analysis of this kind of structure. The numerical results show 13.4 dB gain at 5.6 GHz. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new four-dimensional hyperchaotic system derived from the chaotic maps of Peter de Jong's simple attractor and the discrete iterative function. In this work, our main motivation is to explore a link that can be developed to generate hyperchaos from 2D chaotic system. An association between 2D system and a higher order one was not studied in the previous literature. In fact, in the literature, there is no two-dimensional systems from which we are able to associate a four-dimensional one. In this context, a special interest is reserved to Peter de Jong system due to its exceptional advantages such as hypersensitivity and velocity. The challenge in this paper is the development of a four-dimensional hyperchaotic system associated to the Peter de Jong one while conserving its important characteristics such as hypersensitivity, velocity and the lack of equilibrium. The system structure that we will detail is different from other hyperchaotic systems widely suggested in the literature. In fact, the proposed attractor does not display any equilibrium point. A mathematical study is carried out in order to obtain time plots, Lyapunov exponents spectrum and bifurcation diagram. Finally, we will prove the high sensitivity of this system relative to its initial condition by simulations and experimental observations. [ABSTRACT FROM AUTHOR]

The paper studies numerical properties of LU and incomplete LU factorizations applied to the discrete linearized incompressible Navier-Stokes problem also known as the Oseen problem. A commonly used stabilized Petrov-Galerkin finite element method for the Oseen problem leads to the system of algebraic equations having a 2 × 2-block structure. While enforcing better stability of the finite element solution, the Petrov-Galerkin method perturbs the saddle-point structure of the matrix and may lead to less favorable algebraic properties of the system. The paper analyzes the stability of the LU factorization. This analysis quantifies the effect of the streamline upwind Petrov-Galerkin stabilization in terms of the perturbation made to a nonstabilized system. The further analysis shows how the perturbation depends on the particular finite element method, the choice of stabilization parameters, and flow problem parameters. The analysis of LU factorization and its stability helps to understand the properties of threshold ILU factorization preconditioners for the system. Numerical experiments for a model problem of blood flow in a coronary artery illustrate the performance of the threshold ILU factorization as a preconditioner. The dependence of the preconditioner properties on the stabilization parameters of the finite element method is also studied numerically. [ABSTRACT FROM AUTHOR]

In this paper, we show that the failure of the unique branch hypothesis () for tame iteration trees implies that in some homogenous generic extension of there is a transitive model containing such that is regular. The results of this paper significantly extend earlier works from [Non-tame mice from tame failures of the unique branch bypothesis, Canadian J. Math. 66(4) (2014) 903-923; Core models with more Woodin cardinals, J. Symbolic Logic 67(3) (2002) 1197-1226] for tame trees. [ABSTRACT FROM AUTHOR]

As part of the day-ahead market clearing process, MISO solves one of the most challenging Security Constrained Unit Commitment (SCUC) models. With footprint expansions and increased activity from financial traders, the day-ahead market unit commitment encounters significant performance challenges from time to time. This paper reviews MISO's day-ahead market clearing process and identifies the factors contributing to these performance challenges. It then shares techniques that have been developed to overcome these challenges. Three alternative backup solving approaches were developed. An incremental solving algorithm is proposed to better handle the iterative market clearing process and to perform solution polishing and commitment reason identification. Numerical results based on MISO data are presented. [ABSTRACT FROM PUBLISHER]

This paper suggests a data envelopment analysis (DEA) model for selecting the most efficient alternative in advanced manufacturing technology in the presence of both cardinal and ordinal data. The paper explains the problem of using an iterative method for finding the most efficient alternative and proposes a new DEA model without the need of solving a series of LPs. A numerical example illustrates the model, and an application in technology selection with multi-inputs/multi-outputs shows the usefulness of the proposed approach. [ABSTRACT FROM AUTHOR]

Copula models are becoming increasingly popular in engineering and financial applications. They provide a flexible way of constructing joint distributions with arbitrary one-dimensional margins and a wide variety of dependence structures. This paper studies different types of conditionalization of copula-based models. We conditionalize these models in the usual way on point values but also propose a different type of conditionalization on a new margin. This new type of conditionalization is motivated by experience with a model built for application in modeling risk in civil aviation. Changing one margin in a copula model is very easy; however, it is not equivalent to conditionalizing on a new margin. For this purpose, the technique presented by Holland and Wang [Holland PW, Wang YJ (1987) Dependence function for continuous bivariate densities. Commun. Statist. Theory Methods 16(3):867-876], called marginal replacement, is used. The main result of this paper allows a simplified way of conditionalizing on more than one univariate margin in a normal copula model. [ABSTRACT FROM AUTHOR]

For large sparse saddle point problems, Cao et al. studied a modified generalized parameterized inexact Uzawa (MGPIU) method (see [Y. Cao, M.Q. Jiang, L.Q. Yao, New choices of preconditioning matrices for generalized inexact parameterized iterative methods, J. Comput. Appl. Math. 235 (1) (2010) 263-269]). For iterative methods of this type, the choice of the relaxation parameter is crucial for the methods to achieve their best performance. In this paper, for an example of 2D Stokes equations, we derive the optimal relaxation parameter for the continuous version of the MGPIU method, by minimizing the corresponding convergence factor that is obtained using Fourier analysis. In addition, we find that the MGPIU method is mesh parameter independent, however, it depends asymptotically linearly on the viscosity ν, which suggests that the numerical methods for Stokes equations should be investigated with the presence of the viscosity ν, though it can be scaled out from the equations in advance. We use numerical experiments to validate our theoretical findings. [ABSTRACT FROM AUTHOR]

The paper presents a mathematical model of an ideal filamentary coil with a finite number of turns, derived by means of the method called truncated region eigenfunction expansion (TREE). The proposed solution allows quick computation of the filamentary coil impedance as well as of the impedance changes caused by the presence of a two-layered conductive material. The final formulas were presented in the closed form and implemented in Matlab. The results were verified using the finite element method in the COMSOL Multiphysics package as well as by means of other mathematical models. In all cases they show a very good agreement. The obtained values of coil impedance changes were compared in terms of the time of reaching the final results. In the case of the most significant calculations, which consisted of many iterations, the proposed solution turned out to be by far the fastest one. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the contents of lookup tables (LUTs) of distributed arithmetic (DA)-based block least mean square (BLMS) adaptive filter (ADF) and based on that we propose intra-iteration LUT sharing to reduce its hardware resources, energy consumption, and iteration period. The proposed LUT optimization scheme offers a saving of 60% LUT content for block size 8 and still higher saving for larger block sizes over the conventional design approach. We also present here the design of a register-based LUT matrix for maximal sharing of LUT contents and full-parallel LUT-update operation. Based on the proposed design approach, we have derived a DA-based architecture for the BLMS ADF, which is scalable for larger block sizes as well as higher filter lengths. We find that the hardware complexity of the proposed structure increases less than proportionately with input block size and filter length. It offers a saving of 60% LUT-update per output and 59% LUT access per output over the recently proposed DA-based BLMS ADF structure for block size 8 and filter length 64. Besides, the proposed structure involves nearly 30% saving in the iteration period over the other for 16-bit coefficient word length. Application specific integrated circuit (ASIC) synthesis result shows that the proposed structure for block size 8 offers a saving of 48% area-delay product (ADP) and 53% energy per sample (EPS) over the existing DA-based BLMS ADF structure on average for different filter lengths, and offers 30% higher sampling rate due to its shorter iteration period. Compared with the existing DA-based LMS ADF structure, the proposed structure involves 68% less ADP and $1.6 \times $ less EPS. [ABSTRACT FROM PUBLISHER]

The present paper aims to solve the linear and nonlinear time-fractional Newell-Whitehead-Segel equations using the Sumudu transform iterative method. The time-fractional derivatives are considered in the Caputo sense. In addition, the approximate analytical solutions derived in series form are graphically represented in this investigation, and the solution graphs show that the approximate solution is closely related to the exact solution. [ABSTRACT FROM AUTHOR]

In the early seventies, Shelah proposed a model-theoretic construction, nowadays called "iteration". This construction is an infinite replication in a tree-like manner where every vertex possesses its own copy of the original structure. Stupp proved that the decidability of the monadic second-order (MSO) theory is transferred from the original structure onto the iterated one. In its extended version discovered by Muchnik and introduced by Semenov, the iteration became popular in computer science logic thanks to a paper by Walukiewicz. Compared to the basic iteration, Muchnik's iteration has an additional unary predicate which, in every copy, marks the vertex that is the clone of the possessor of the copy. A widely spread belief that this extension is crucial is formally confirmed in the paper. Two hierarchies of relational structures generated from finite structures by MSO interpretations and either Shelah-Stupp's iteration or Muchnik's iteration are compared. It turns out that the two hierarchies coincide at level 1. Every level of the latter hierarchy is closed under Shelah-Stupp's interation. In particular, the former hierarchy collapses at level 1. [ABSTRACT FROM AUTHOR]

In this paper, a variational Bayesian (VB)-based iterative algorithm for ARX models with random missing outputs is proposed. The distributions of missing outputs can be estimated in the VB-E step, and the distributions of unknown parameters can be estimated in the VB-M step by the estimated missing outputs and the available outputs. Compared with the expectation-maximization-based iterative algorithm, this algorithm computes the latent variable and the parameter distributions at each iteration. Therefore, it is more accurate. The simulation results demonstrate the advantages of the proposed algorithm. [ABSTRACT FROM AUTHOR]

The corrective calibration of the removal function plays an important role in the magnetorheological finishing (MRF) high-accuracy process. This paper mainly investigates the asymmetrical characteristic of the MRF removal function shape and further analyzes its influence on the surface residual error by means of an iteration algorithm and simulations. By comparing the ripple errors and convergence ratios based on the ideal MRF tool function and the deflected tool function, the mathematical models for calibrating the deviation of horizontal and flowing directions are presented. Meanwhile, revised mathematical models for the coordinate transformation of an MRF machine is also established. Furthermore, a Ø140-mm fused silica plane and a Ø196  mm, f/1∶1, fused silica concave sphere samples are taken as the experiments. After two runs, the plane mirror final surface error reaches PV 17.7 nm, RMS 1.75 nm, and the polishing time is 16 min in total; after three runs, the sphere mirror final surfer error reaches RMS 2.7 nm and the polishing time is 70 min in total. The convergence ratios are 96.2% and 93.5%, respectively. The spherical simulation error and the polishing result are almost consistent, which fully validate the efficiency and feasibility of the calibration method of MRF removal function error using for the high-accuracy subaperture optical manufacturing. [ABSTRACT FROM AUTHOR]

This paper proposes an efficient parameter extraction algorithm for GaN high electron mobility transistors small-signal equivalent circuit model. The algorithm combines parameter scanning and iteration methods to solve the problem of error accumulation in conventional methods and is implemented in matlab programming. By using the iteration method, the algorithm each time uses more accurate element values thus makes the results converge to the optimal value faster. A 20-element small-signal equivalent circuit model of GaN high electron mobility transistors is used to validate the proposed algorithm, and the results show that the calculated S-parameters agree well with the measured S-parameters within the frequency range of 0.1 to 40 GHz. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The paper presents the determination of the kinematic model equations for the 5R-type articulated industrial robot that can be applied in welding processes. The method used to perform this modeling is the iterative method and it takes the advantages of the previously determined equations of the geometric model. The operational kinematic parameters (linear and angular velocities and accelerations) are eventually determined. They represent the equations of the direct kinematic model. [ABSTRACT FROM AUTHOR]

A deceleration guidance law is developed for a reentry warhead with a fixed angle of attack by body geometry and a single moving-mass for attitude control. The guidance model equations, including the dynamic equations of the moving-mass two-body system and the kinematic equations between the warhead and the target, which form the basis of the study, are presented. To analyze the guidance model, the equations are simplified and new variables are introduced. By simplifying the guidance model equations, the transfer functions from the lateral position of the internal mass to the error angle are obtained. Iteration of the error angle is used to control the terminal velocity at a desired value. For the moving-mass reentry warhead studied in this paper, the relationship between the miss distance and the magnitude of the error angle is developed, and precision guidance can be achieved. Nonlinear seven-degree-of-freedom trajectory simulations verify the transfer functions and demonstrate the ability of the guidance law with deceleration control in a typical reentry mission. [ABSTRACT FROM AUTHOR]

In this paper we propose a modified Elliptic Net algorithm to compute pairings. By reducing the number of the intermediate variables which should be updated in the iteration loop of the Elliptic Net algorithm, we speed up the computation of pairings. Experimental results show that the proposed method is more efficient than the original Elliptic Net algorithm on Barreto-Naehrig (BN) curves which are the best choice for implementing pairings at 128-bit security level. [ABSTRACT FROM PUBLISHER]

In digital tomosynthesis imaging, multiple projections of an object are obtained along a small range of different incident angles in order to reconstruct a pseudo-3D representation of the object. In this paper we discuss a mathematical model for polyenergetic digital breast tomosynthesis image reconstruction that explicitly takes into account various materials composing the object and the polyenergetic nature of the x-ray beam. Our model allows for computing weight fractions of the individual materials that make up the object, which can then be used to reconstruct pseudo-3D images. The reconstruction process requires solving a large-scale inverse problem, which is done with a gradient descent iteration. Regularization is enforced by truncating the iteration. The mathematical model is described in detail, as is an efficient approach to compute the gradient of the objective function. The effectiveness of our approach is illustrated with real data taken of an object with known materials that simulates an actual breast. [ABSTRACT FROM AUTHOR]

This paper presents analytic solutions to the integral moving least squares (MLS) equations originally proposed by Shen et al. by choosing another specific weighting function that renders the numerator in the MLS equation unitless. In addition, we analyze the original method to show that their approximation surfaces (i.e., enveloping surfaces with nonzero \epsilon values in the weighting function) often form zero isosurfaces near concavities behind the triangle-soup models. This paper also presents error terms for the integral MLS formulations against signed distance fields. Based on our analytic solutions, we show that our method provides both interpolation and approximation surfaces faster and more efficiently. Because our method computes solutions for integral MLS equations directly, it does not rely on numerical steps that might have numerical-accuracy issues. In particular, unlike the original method that deals with incorrect approximation surfaces by iteratively adjusting parameters, this paper proposes faster and more efficient approximations to surfaces without needing iterative routines. We also present computational efficiency comparisons, in which our method is 15-fold faster in computing integrations, even with conservative assumptions. Finally, we show that the surface normal vectors on the implicit surfaces formed by our analytic solutions are identical to the angle-weighted pseudonormal vectors. [ABSTRACT FROM AUTHOR]

Deadlock control of flexible manufacturing systems (FMS) using Petri nets has been a very active research topic for the past two decades. Siphon-based deadlock control of FMS suffers from reaching fewer states than those of optimal control. This paper proposes three sets of siphon-based liveness-enforcing supervisors (LES) for a well-known FMS to obtain near optimal solutions. The first set includes 11 control places (monitors) providing 21,363 good states. The second set consists of 14 monitors providing 21,562 good states, the same as that using the method of the first-met bad marking (FBM) (based on an iterative method using reachability graph analysis) but with fewer monitors and control arcs. This result is achieved by refining some monitors into several monitors with smaller controller regions, causing fewer disturbances to the original uncontrolled model. The third set contains 15 monitors providing 21,573 good states – the best suboptimal solution so far in the literature. This result is obtained by further shrinking the controller region of the second set. Formal proof of the correctness is provided. Although reaching eight states fewer than that by the set-covering approach, it does not employ weighted control arcs and runs more efficiently. It also computes all lost states based on invariant without reachability analysis. Application to another well-known example is also illustrated. [ABSTRACT FROM AUTHOR]

The first aim of this paper is to give emphasis to the importance of assessing phase information when reconstructing and mapping a sound field. In fact, in acoustic analysis phase distribution is frequently simply either not considered or ignored, even though it can supply very useful information for the understanding of the mapping itself or for further analyses. In this paper a procedure to carry out phase mapping of acoustic sources in beamforming measurement is illustrated. The second aim of this paper is to propose a straightforward iterative optimization algorithm based on the monopole substitution starting from beamforming results. It allows for the reconstruction of sound field without the use of any matrix inversion. Both numerical and experimental validations of the method are presented. Results shown hereafter prove the effectiveness of the approach. [ABSTRACT FROM AUTHOR]

Recent advances in dynamic elastography and biorheology have revealed that the complex shear modulus, G*, of various biological soft tissues obeys a frequency-dependent powerlaw. This viscoelastic powerlaw behavior implies that mechanical properties are communicated in tissue across the continuum of scales from microscopic to macroscopic. For deriving constitutive constants from the dispersion of G* in a biological tissue, a hierarchical fractal model is introduced that accounts for multiscale networks. Effective-media powerlaw constants are derived by a constitutive law based on cross-linked viscoelastic clusters embedded in a rigid environment. The spatial variation of G* is considered at each level of hierarchy by an iterative coarse-graining procedure. The establishment of cross-links in this model network is associated with an increasing fractal dimension and an increasing viscoelastic powerlawexponent. This fundamental relationship between shear modulus dynamics and fractal dimension of the mechanical network in tissue is experimentally reproduced in phantoms by applying shear oscillatory rheometry to layers of tangled paper strips embedded in agarose gel. Both model and experiments demonstrate the sensitivity of G* to the density of the mechanical network in tissue, corroborating disease-related alterations of the viscoelastic powerlaw exponent in human parenchyma demonstrated by in vivo elastography. [ABSTRACT FROM AUTHOR]

This paper proposes a new fuzzy regression model, i.e., the fuzzy system constructed by rule generation and iterative linear support vector regression (FS-RGLSVR) for structural risk minimization. The FS-RGLSVR is composed of Takagi–Sugeno (TS)-type fuzzy if–then rules. These rules are automatically constructed by a self-splitting rule generation algorithm that introduces the self-splitting technique to the k-means clustering algorithm. This new algorithm regards a cluster as a fuzzy rule, where no preassignment of the cluster (rule) number is necessary. The cost function for parameter learning is defined based on structural risk instead of empirical risk minimization in order to achieve generalizability. Tuning all of the free parameters in the FS-RGLSVR using linear support vector regression (SVR) is proposed to minimize the cost function. Each of the consequent and antecedent part parameters is expressed as a linear combination coefficient in a transformed input space so that the linear SVR is applicable. This paper introduces iterative linear SVR to tune antecedent and consequent parameters. This paper demonstrates the capabilities of FS-RGLSVR by two simulated and four practical regression examples. Comparisons with fuzzy systems with different types of learning algorithms verify the performance of the FS-RGLSVR. [ABSTRACT FROM PUBLISHER]

This paper examines the allocation of yard cranes and blocks for yard activities in container terminals. In this paper, the yard cranes are confined to rail mounted gantry cranes (RMGC), which are characterized by the restricted traveling range on a pair of rails. Since RMGCs and yard blocks are tightly bound to each other, when allocating them, we should make sure that the RMGCs allocated for a yard activity are able to together cover the blocks allocated for the corresponding yard activity. In addition, considering that there are four basic activities occurring in the yard which compete with each other for the scarce resources and have different requirements and priorities in the allocation of blocks and yard cranes, we treat them in a single model rather than in multiple independent models as were generally done in literature. A mixed integer programming model is constructed, and an iterative decomposition solution procedure is proposed for the problem. Based on the solution procedure, a decision support system is developed and implemented for a terminal in Tianjin seaport. Using the actual data, the numerical experiments show the effectiveness and efficiency of the decision support system. [ABSTRACT FROM AUTHOR]

Purpose - This paper aims to present how iterative round-trip modelling between two different business process modelling tools can be enabled on a conceptual level. Iterative round-trip modelling addresses model transformations between high-level business and executable process models, and how to maintain these transformations in change time. Currently, the development of these process models is supported by different tools. To the authors'' best knowledge, no coherent collaborative tool environment exists that supports iterative round-trip modelling. Design/methodology/approach - This paper is primarily based on a literature review of state-of-the-art business to IT transformations regarding business process modelling. The architecture of integrated information systems (ARIS) and Cordys tools are used as an example case in this research. ARIS is a business process analysis (BPA) tool suited for analyzing and designing business processes, while the execution and monitoring of these processes is allowed by Cordys, a business process management suite (BPMS). The theory is used for transforming between ARIS event-driven process chains from the business perspective and business process modelling notation in Cordys from the IT perspective. Findings - A conceptual framework is proposed to couple a BPA and BPMS tool for round-trip business process modelling. The framework utilizes concepts from the model-driven architecture for structurally addressing interoperability and model transformations. Ensuring iterative development with two tools requires traceability of model transformations. Practical implications - In many organizations, BPA and BPMS tools are used for business process modelling. These are in practice often two different worlds, while they concern around the same business processes. Maintaining multiple versions of the same process models across two tools is a considerable task, as they often are subject to design changes. Interoperability between a BPA and BPMS tool will minimize redundant activities, and reduce business to IT deployment time. Originality/value - This research provides a theoretical base for coupling a BPA and BPMS tool regarding iterative round-trip modelling. It provides an overview of the current state-of-the-art literature of business process modelling transformations, and what is necessary for maintaining interoperability between tools. The findings indicate what is expected in tool support for iterative development in business process modelling from analysis and design to execution. [ABSTRACT FROM AUTHOR]

In this paper, the He's principles will be used to carry out the integration of the Rosenau-Kawahara equation. The variational iteration method as well as Homotopy perturbation method will be used to carry out the integration of this equation. Finally, the analytical method that is known as He's semi-inverse variational principle will also be used to obtain a closed form analytical 1-soliton solution to this equation. The numerical simulations are given to support the results. [ABSTRACT FROM AUTHOR]

This paper proposes a new approach for solving generation scheduling and ramp rate constrained unit commitment (GSRCUC) considering spinning reserve uncertainty. In order to handle reserve uncertainty the estimated probability that spinning reserve might be called and delivered is taken into account. A combinatorial genetic algorithm and lambda iteration method is applied to solve such problem. The proposed methodology is implemented to a 10-unit base problem and a 26-unit IEEE reliability test system. The performance of GSRCU model associated with the impact of spinning reserve requirement (SRR) probability is studied in this paper. Numerical results show a significant improvement in the solutions of a cost-based unit commitment in comparison with the other studies. [ABSTRACT FROM AUTHOR]

This paper presents a new triaxial accelerometer calibration method using a mathematical model of six calibration parameters: three gain factors and three biases. The fundamental principle of the proposed calibration method is that the sum of the triaxial accelerometer outputs is equal to the gravity vector when the accelerometer is stationary. The proposed method requires the triaxial accelerometer to be placed in six different tilt angles to estimate the six calibration parameters. Since the mathematical model of the calibration parameters is nonlinear, an iterative method is used. The results are verified via simulations by comparing the estimated gain factors and biases with the true gain factors and biases. The simulation results confirm that the proposed method is applicable in extreme cases where the gain factor is 1000 V/(m/s²) and the bias is ±100 V, as well as the cases where the gain factor is 0.001 V/(m/s²) and the bias is 0 V. The proposed calibration method is also experimentally tested with two different triaxial accelerometers, and the results are validated using a mechanical inclinometer. The experimental results show that the proposed method can accurately estimate gain factors and biases even when the initial guesses are not close to the true values. In addition, the proposed method has a low computational cost because the calculation is simple, and the iterative method usually converges within three iteration steps. The error sources of the experiments are discussed in this paper. [ABSTRACT FROM AUTHOR]

In this note, a technical error is pointed out in the proof of a lemma in the above paper. A correct proof of this lemma is given. In addition, a further result on the algorithm in the above paper is also given. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Time division multiple access (TDMA) based medium access control (MAC) protocols can provide QoS with guaranteed access to the wireless channel. However, in multi-hop wireless networks, these protocols may introduce scheduling delay if, on the same path, an outbound link on a router is scheduled to transmit before an inbound link on that router. The total scheduling delay can be quite large since it accumulates at every hop on a path. This paper presents a method that finds conflict-free TDMA schedules with minimum scheduling delay. We show that the scheduling delay can be interpreted as a cost, in terms of transmission order of the links, collected over a cycle in the conflict graph. We use this observation to formulate an optimization, which finds a transmission order with the min-max delay across a set of multiple paths. The min-max delay optimization is NP-complete since the transmission order of links is a vector of binary integer variables. We devise an algorithm that finds the transmission order with the minimum delay on overlay tree topologies and use it with a modified Bellman-Ford algorithm, to find minimum delay schedules in polynomial time. The simulation results in 802.16 mesh networks confirm that the proposed algorithm can find effective min-max delay schedules. [ABSTRACT FROM AUTHOR]

This paper provides simple lower bounds on the number of iterations which is required for successful message-passing decoding of some important families of graph-based code ensembles (including low-density parity-check (LDPC) codes and variations of repeat-accumulate codes). The transmission of the code ensembles is assumed to take place over a binary erasure channel, and the bounds refer to the asymptotic case where we let the block length tend to infinity. The simplicity of the bounds derived in this paper stems from the fact that they are easily evaluated and are expressed in terms of some basic parameters of the ensemble which include the fraction of degree-2 variable nodes, the target bit erasure probability, and the gap between the channel capacity and the design rate of the ensemble. This paper demonstrates that the number of iterations which is required for successful message-passing decoding scales at least like the inverse of the gap (in rate) to capacity, provided that the fraction of degree-2 variable nodes of these turbo-like ensembles does not vanish (hence, the number of iterations becomes unbounded as the gap to capacity vanishes). [ABSTRACT FROM AUTHOR]

This paper considers the maximization of information rates for the Gaussian frequency-selective interference channel, subject to power and spectral mask constraints on each link. To derive decentralized solutions that do not require any cooperation among the users, the optimization problem is formulated as a static noncooperative game of complete information. To achieve the so-called Nash equilibria of the game, we propose a new distributed algorithm called asynchronous iterative water-filling algorithm. In this algorithm, the users update their power spectral density (PSD) in a completely distributed and asynchronous way: some users may update their power allocation more frequently than others and they may even use outdated measurements of the received interference. The proposed algorithm represents a unified framework that encompasses and generalizes all known iterative water-filling algorithms, e.g., sequential and simultaneous versions. The main result of the paper consists of a unified set of conditions that guarantee the global converge of the proposed algorithm to the (unique) Nash equilibrium of the game. [ABSTRACT FROM AUTHOR]

The analysis of medical images requires image segmentation to distinguish the boundaries of irregular regions such as tumors in images. However, segmentation of medical images with intensity inhomogeneity has always been a challenging task in image processing. In this paper, we have proposed a new model for segmentation of medical image having inhomogeneous intensities. In the proposed model, we have used hybrid image data obtained from the product of given image with smooth image and difference of smooth product image from product image. The model uses both local and global information of the image. The proposed model outperforms the existing models qualitatively and quantitatively i.e. in terms of number of iterations and CPU time. For the solution of proposed model we have used some of the numerical schemes such as Explicit and Semi-Implicit schemes. The model is further tested for different type of real medical images. The results showed that the proposed model also performs well in images having intensity inhomogeneity and blurred edges as well. [ABSTRACT FROM AUTHOR]

In the circularly polarized dielectric resonator antenna (CP-DRA), the one-point feed method with a simplified configuration of the feed system is studied. Although the CP-DRA using a rectangular dielectric body requires a simple fabrication process, the excitation condition for a circular polarization is not clear yet. This paper studies a design method for a CP-DRA generating a circular polarization with one probe placed at the external location of a rectangular dielectric body. As the first step of the design, the procedure used in the design of a conventional circularly polarized microstrip antenna is applied to this CP-DRA. In the second stage of the design, an optimum structure of the CP-DRA generating a circular polarization with matching to a feed system is determined by an iterative analysis of the structure including the excitation section by means of the modal polarization current model method (M-PCMM). It is shown in the second stage of the design that the M-PCMM is useful. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(11): 1–10, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10216 [ABSTRACT FROM AUTHOR]

In this paper, we establish an iterative algorithm and estimation of solutions for a fractional turbulent flow model in a porous medium under a suitable growth condition. Our main tool is the monotone iterative technique. [ABSTRACT FROM AUTHOR]

This paper focuses on the use of quadratic time-frequency distributions (QTFDs) to characterize the temporal variation of low-frequency electromechanical oscillations (LFEOs) using ringdown data. A refined Margenau-Hill distribution (MHD) and a procedure to extract the instantaneous frequencies and damping factors as well as initial phase angles of system low-frequency modes when the analyzed signal is multi-component are proposed. The refinement process enjoys a fast-converging iterative algorithm and without loss of generality it can be applied to other QTFDs for using in other applications. A non-stationary synthetic signal as well as simulated ringdown data of a 5-area, 16-machine power system and real measured data of Western Systems Coordinating Council (WSCC) system are used to demonstrate the efficiency of the proposed method in the presence of measurement noise. [ABSTRACT FROM AUTHOR]

The paper deals with a steady state version of a nonlocal nonlinear parabolic problem defined on a bounded polygonal domain. The nonlocal term involved in the strong formulation essentially increases the complexity of the problem and the necessary total computational work. The nonlinear weak formulation of the problem is reduced to a linear one suitable for applications of Newtonian type iterative methods. A discrete problem is obtained by the FEM. A fast and stable iterative method with ninth-order of convergence is applied for solving the discrete problem. The iterative algorithm is described by a pseudo-code. The method is computer implemented and the approximate solutions are presented graphically. [ABSTRACT FROM AUTHOR]

Standby redundancy has been extensively applied to critical engineering systems to enhance system reliability. Researches on reliability evaluation for standby systems focus more on systems with binary‐state elements. However, multi‐state elements with different performances have played a significant role in engineering systems. This paper presents an approach for reliability analysis of standby systems composed of multi‐state elements with constant state transition rates and absorbing failure states. The approach allows modelling different standby systems beyond cold, warm and hot ones by taking into account differences in possible maintenance of elements in standby and operation modes and dependence of elements' operational behavior on their initial state at the time of activation. An iterative algorithm for reliability evaluation based on element state probabilities is suggested. Illustrating examples of evaluating reliability of different types of homogeneous and heterogeneous standby systems are demonstrated. [ABSTRACT FROM AUTHOR]

This paper is concerned with model reduction for Markov chain models. The goal is to obtain alow-rank approximationto the original Markov chain. The Kullback–Leibler divergence rate is used to measure the similarity between two Markov chains; the nuclear norm is used to approximate the rank function. A nuclear-norm regularised optimisation problem is formulated to approximately find the optimal low-rank approximation. The proposed regularised problem is analysed and performance bounds are obtained through the convex analysis. An iterative fixed point algorithm is developed based on the proximal splitting technique to compute the optimal solutions. The effectiveness of this approach is illustrated via numerical examples. [ABSTRACT FROM AUTHOR]

We construct a number system for representing numbers in [0, 1] that is based on iterations of an asymmetric tent map that incorporates the golden ratio. It is already known that in this system a number has a periodic representation if and only if it lies in . We investigate other aspects of this system such as non-uniquely representable numbers, an inherent semigroup structure, connections with Wythoff's game, related sequences of rational functions, and its connection with an iterative scheme reminiscent of paper folding analysis. Many details of the above-mentioned connections are conjectural. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to introduce and consider a new hybrid shrinking projection method for finding a common element of the set EP of solutions of a generalized equilibrium problem, the common fixed point set F of finite uniformly closed families of countable Bregman quasi-Lipschitz mappings in reflexive Banach spaces. It is proved that under appropriate conditions, the sequence generated by the hybrid shrinking projection method converges strongly to some point in $\mathit{EP} \cap F$. Relative examples are given. Strong convergence theorems are proved. The application for Bregman asymptotically quasi-nonexpansive mappings is also given. The main innovative points in this paper are as follows: (1) the notion of the uniformly closed family of countable Bregman quasi-Lipschitz mappings is presented and the useful conclusions are given; (2) the relative examples of the uniformly closed family of countable Bregman quasi-Lipschitz mappings are given in classical Banach spaces $l^{2}$ and $L^{2}$; (3) the application for Bregman asymptotically quasi-nonexpansive mappings is also given; (4) because the main theorems do not need the boundedness of the domain of mappings, so a corresponding technique for the proof is given. This new results improve and extend the previously known ones in the literature. [ABSTRACT FROM AUTHOR]

The assessment of pavement cracks is one of the essential tasks for road maintenance. This paper presents a novel framework, called ITVCrack, for automated crack extraction based on iterative tensor voting (ITV), from high-density point clouds collected by a mobile laser scanning system. The proposed ITVCrack comprises the following: 1) the preprocessing involving the separation of road points from nonroad points using vehicle trajectory data; 2) the generation of the georeferenced feature (GRF) image from the road points; and 3) the ITV-based crack extraction from the noisy GRF image, followed by an accurate delineation of the curvilinear cracks. Qualitatively, the method is applicable for pavement cracks with low contrast, low signal-to-noise ratio, and bad continuity. Besides the application to GRF images, the proposed framework demonstrates much better crack extraction performance when quantitatively compared to existing methods on synthetic data and pavement images. [ABSTRACT FROM PUBLISHER]