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The purpose of this paper is to simulate numerical solutions of nonlinear Burgers' equation with two well‐known problems in order to verify the accuracy of the cubic B‐spline differential quadrature methods.

Cubic B‐spline differential quadrature methods have been used to discretize the Burgers' equation in space and the resultant ordinary equation system is integrated via Runge‐Kutta method of order four in time. Numerical results are compared with each other and some former results by calculating discrete root mean square and maximum error norms in each case. A matrix stability analysis is also performed by determining eigenvalues of the coefficient matrices numerically.

Numerical results show that differential quadrature methods based on cubic B‐splines generate acceptable solutions of nonlinear Burgers' equation. Constructing hybrid algorithms containing various basis to determine the weighting coefficients for higher order derivative approximations is also possible.

Nonlinear Burgers' equation is solved by cubic B‐spline differential quadrature methods.

A fixed grid representation of the finite element domain is used to solve elasticity problems. An integration between CAD and FEM systems is made by using this fixed grid representation. Some considerations about FG approximation and stiffness matrix generation are presented. The element stiffness matrix for an element in the mesh is obtained as a factor of a standard element stiffness matrix. A least squares local approximation of stress field is used to calculate the stress at boundary elements. A problem with an analytical solution is used to measure the displacement and stress error. Several meshes and several geometrical configurations of the problem are used to test the reliability of the fixed grid finite element method.

The purpose of this paper is to develop a fast and accurate analytic model function for the single-valued H-B curve of ferromagnetic materials, where hysteresis can be disregarded (normal magnetization curve). Nonlinear magnetoquasistatic simulations demand smooth monotone material models to ensure physical correctness and good convergence in Newton's method.

The Brauer model has these beneficial properties, but is not sufficiently accurate for low and high fields in the normal magnetization curve. The paper extends the Brauer model to better fit material behavior in the Rayleigh region (low fields) and in full saturation. Procedures for obtaining optimal parameters from given measurement points are proposed and tested for two technical materials. The approach is compared with cubic spline and monotonicity preserving spline interpolation with respect to error and computational effort.

The extended Brauer model is more accurate and even maintains the computational advantages of the classical Brauer model. The methods for obtaining optimal parameters yield good results if the measurement points have a distinctive Rayleigh region.

The model function for ferromagnetic materials enhances the precision of the classical Brauer model without notable additional simulation cost.

This paper aims to propose a new adaptive strategy for two-dimensional (2D) nonlinear finite element (FE) analysis of the minimal surface problem (MSP) based on the element energy projection (EEP) technique.

By linearizing nonlinear problems into a series of linear problems via the Newton method, the EEP technique, which is an effective and reliable point-wise super-convergent displacement recovery strategy for linear FE analysis, can be directly incorporated into the solution procedure. Accordingly, a posteriori error estimate in maximum norm was established and an adaptive 2D nonlinear FE strategy of h-version mesh refinement was developed.

Three classical known surfaces, including a singularity problem, were analysed. Moreover, an example whose analytic solution is unavailable was considered and a comparison was made between present results and those computed by the MATLAB PDE toolbox. The results show that the adaptively-generated meshes reflect the difficulties inherent in the problems and the proposed adaptive analysis can produce FE solutions satisfying the user-preset error tolerance in maximum norm with a fair adaptive convergence rate.

The EEP technique for linear FE analysis was extended to the nonlinear procedure of MSP and can be expected to apply to other 2D nonlinear problems. The employment of the maximum norm makes point-wisely error control on the sought surfaces possible and makes the proposed method distinguished from other adaptive FE analyses.

This study aims to propose a general and efficient adaptive strategy with local mesh refinement for two-dimensional (2D) finite element (FE) analysis based on the element energy projection (EEP) technique.

In view of the inflexibility of the existing global dimension-by-dimension (D-by-D) recovery method via EEP technique, in which displacements are recovered through element strips, an improved element D-by-D recovery strategy was proposed, which enables the EEP recovery of super-convergent displacements to be implemented mostly on a single element. Accordingly, a posteriori error estimate in maximum norm was established and an EEP-based adaptive FE strategy of h-version with local mesh refinement was developed.

Representative numerical examples, including stress concentration and singularity problems, were analyzed; the results of which show that the adaptively generated meshes reasonably reflect the local difficulties inherent in the physical problems and the proposed adaptive analysis can produce FE displacement solutions satisfying the user-specified tolerances in maximum norm with an almost optimal adaptive convergence rate.

The proposed element D-by-D recovery method is a more efficient and flexible displacement recovery method, which is implemented mostly on a single element. The EEP-based adaptive FE analysis can produce displacement solutions satisfying the specified tolerances in maximum norm with an almost optimal convergence rate and thus can be expected to apply to other 2D problems.

A general strategy is developed for adaptive finite element (FE) analysis of free vibration of elastic membranes based on the element energy projection (EEP) technique.

By linearizing the free vibration problem of elastic membranes into a series of linear equivalent problems, reliable a posteriori point-wise error estimator is constructed via EEP super-convergent technique. Hierarchical local mesh refinement is incorporated to better deal with tough problems.

Several classical examples were analyzed, confirming the effectiveness of the EEP-based error estimation and overall adaptive procedure equipped with a local mesh refinement scheme. The computational results show that the adaptively-generated meshes reasonably catch the difficulties inherent in the problems and the procedure yields both eigenvalues with required accuracy and mode functions satisfying user-preset error tolerance in maximum norm.

By reasonable linearization, the linear-problem-based EEP technique is successfully transferred to two-dimensional eigenproblems with local mesh refinement incorporated to effectively and flexibly deal with singularity problems. The corresponding adaptive strategy can produce both eigenvalues with required accuracy and mode functions satisfying user-preset error tolerance in maximum norm and thus can be expected to apply to other types of eigenproblems.

The major challenges in the modern-day wireless communication systems are increased co-channel interference owing to large number of users and the increased energy consumption owing to high circuit and/or hardware power consumption. Hence, the purpose of this paper is to present a practical approach involving linear precoding, channel estimation, user selection (US) and transmit antenna selection (AS) for enhanced reliability in multiuser multiple-input multiple output (MU-MIMO) system.

The proposed technique considers systematic and optimum deployment of users and transmits antennas for each selected user which enhances the sum rate or the system capacity. The comparison of algorithms, namely, norm-based and capacity-based US is presented with its implementation with precoding techniques, namely, block-diagonalization (BD) and zero-forcing with combining (ZFC) which is used to minimize co-channel interference. In this paper, a power consumption model is proposed for energy efficiency calculation in MU-MIMO system. Also, post analysis, the variant of US and AS algorithms optimizing the performance of BD and ZFC precoding technique is proposed.

It is seen that the proposed MU-MIMO system with norm-based US and norm-based AS improves over existing US-based systems by 43% in terms of sum rate and 19% in terms of energy efficiency for 100 users.

It is seen that the proposed MU-MIMO system with norm-based US and norm-based AS improves over existing US-based systems by 43% in terms of sum rate and 19% in terms of energy efficiency for 100 users.

The purpose of this paper is to analyse the driving factors of e-books’ illegal downloading and price acceptance from a theoretical perspective that embraces ethical and technological aspects. The diffusion of e-readers and tablets has led to a spate of pirated copies of books.

The proposed model holds that normative and value consciousness, as well as the self-efficacy, the usefulness and the use of the new technology, are determinants of the trend towards free downloads and the maximum acceptable price for e-books. Data are collected from a sample of 227 users of e-book reader devices.

The results provide evidence that individuals are inclined towards piracy when they use and control the technology, whereas value consciousness mitigates illegal downloading and is basic to the individuals’ acceptance of a higher price.

Bearing in mind that the spread of electronic devices has led to an increase in downloads, raising awareness of the norms among individuals is essential if piracy is to be curtailed. In addition, actions aimed at endowing electronic books with value would encourage consumers to pay a higher price for them.

Few attempts have been made to apply ethics theories and the technology acceptance model to the context of e-books’ piracy, and even less effort has been devoted to analyse consumers’ price acceptance in the e-book industry.

Culture is a central concept broadly studied in social anthropology and sociology. It has been gaining increasing attention in economics, appearing in research on labor market discrimination, identity, gender, and social preferences. Most experimental economics research on culture studies cross-national or cross-ethnic differences in economic behavior. In contrast, we explain laboratory behavior using two cultural dimensions adopted from a prominent general cultural framework in contemporary social anthropology: group commitment and grid control. Groupness measures the extent to which individual identity is incorporated into group or collective identity; gridness measures the extent to which social and political prescriptions intrinsically influence individual behavior. Grid-group characteristics are measured for each individual using selected items from the World Values Survey. We hypothesize that these attributes allow us to systematically predict behavior in a way that discriminates among multiple forms of social preferences using a simple, parsimonious deductive model. The theoretical predictions are further tested in the economics laboratory by applying them to the dictator, ultimatum, and trust games. We find that these predictions are confirmed overall for most experimental games, although the strength of empirical support varies across games. We conclude that grid-group cultural theory is a viable predictor of people’s economic behavior, then discuss potential limitations of the current approach and ways to improve it.

It has constantly been important to investigate the distribution of magnetic fields in high temperature superconducting (HTS) transformers because the high magnetic field applied to the HTS tapes reduces the critical current and increases the ac losses. The purpose of this study is investigation of the impact of the radius of double pancake windings on the electromagnetic behavior of HTS transformer. In this paper, by changing the radius of the windings in a step-by-step manner in two modes, the electromagnetic behaviors in double pancakes (DPs) of a single-phase HTS transformer have been investigated.

In this paper a 15.4 kVA single-phase HTS transformer has been designed and simulated using the finite element method, using COMSOL multiphysics software. The effect of changing the radius of the low-voltage (LV) and high-voltage (HV) windings on the electromagnetic parameters such as distribution of circulating currents and magnetic field in the LV DP windings has been investigated.

According to the results, by increasing the radius of the LV winding, the electromagnetic behavior of the highest and lowest DPs becomes highly undesirable, while in other DPs, it becomes desirable. The same thing happens by increasing the radius of the LV and HV windings, but with much less intensity. Therefore, according to Ce, the most optimal case is when the two windings (HV and LV) are close to each other and to the core, and if the radius needs to be increased, it is better to increase the radius of both windings.

For the first time, the impact of the radius of DP windings on the electromagnetic behavior of HTS transformer has been investigated.