118 research outputs found
Global Range Restricted GMRES for Linear Systems with Multiple Right Hand Sides
This work concerns the solution of non-symmetric, sparse linear systems with multiple right hand sides by iterative methods. Herein a global version of the range restricted generalized minimal residual method (RRGMRES) is proposed for solving this sort of problems. Numerical results confirm that this new algorithm is applicable
Exact solutions of the Kudryashov–Sinelshchikov equation and nonlinear telegraph equation via the first integral method
In this article we find the exact traveling wave solutions of the Kudryashov–Sinelshchikov equation and nonlinear telegraph equation by using the first integral method. This method is based on the theory of commutative algebra. This method can be applied to nonintegrable equations as well as to integrable ones
An Efficient Technique for Solving Special Integral Equations
In this paper, we apply a new technique for solving two-dimensional integral equations of mixed type. Comparisons are made between the homotopy perturbation method and the new technique. The results reveal that the new technique is effective and convenient
The Impact of Edmodo as an Asynchronous Online Discussion Forum on English Reading Comprehension Skills of Iranian Learners
Online discussion forums (ODFs) offer students and teachers the opportunity to harness the endless power of the internet for educational purposes. This study investigates the impact of Edmodo as an asynchronous ODF on six of the most recurring reading comprehension skills in the TOEFL iBT test among Iranian learners. Online and offline treatments were given to 26 students in the experimental group and only offline treatments to 33 students in the control group. The statistical analysis of the data represents a large effect size (Partial η2=.234; r=.826; Partial η2=.397; r=.661) for identifying factual information, making inferences, guessing vocabulary from context, and inserting texts in the passage skills respectively, a moderate effect size (r=.363) for the understanding the rhetorical purpose of the passage, and a weak effect size (r=.156) for the identifying referential relationships between the words in the passage skills. The results tell us that Edmodo is effective in teaching reading comprehension skills by overcoming the usual time constraints and offering students autonomy in going online at the most convenient time and place. Finally, the findings are valuable for educational policymakers, curriculum designers, materials developers, language instructors, and language learners
Comparative Analysis of the Impact of the Four Elements of Strategic Plan on Product and Market Development in Zinc Companies
Objective :This study was to analyze the impact of each of four elements of strategic plan (vision processing, analysis of external environment, inter- organization analysis and strategic control) on product and market development in zinc companies in Zanjan province.Methodology:Based on objective, this was a descriptive - explanatory study, while it could be defined a cross-sectional one based on time. According to the result, it was an applied research and a quantitative and qualitative based on variables. Finally, it was a surveying study according to data collection method. The target population members included 120 CEOs and business managers of companies active in the zinc industry in Zanjan Province, which were evaluated by census method. The data collection tool was a questionnaire and SPSS software was used for data statistical analysis. The hypotheses were also tested using single-sample t-test and ANOVA.Results : The "vision processing or building" does not affect the product and market development, but three factors of "external environment analysis, inter-organizational analysis and strategic control" affect the development of the market and the product of zinc companies. The most effective factor is "strategic control", and the least effective factor is "external environment analysis"
Artificial Neural Network prediction of Cu–Al2O3 composite properties prepared by powder metallurgy method
AbstractArtificial Neural Networks (ANNs) are excellent tools for prediction of complex processes that have many variables and complex interactions. In the present study, the properties of copper based composite prepared from sintering of mechanically alloyed powders, were predicted using Artificial Neural Network (ANN) approach. In order to prepare copper based composites, copper powder with four different amounts of Al2O3 reinforcement (1, 1.5, 2, 2.5wt%) were mechanically alloyed and the consolidated compacts of prepared powders were sintered in five different temperatures of 725–925°C at seven several sintering times of 15–180min. Hardness and electrical conductivity measurements were performed to evaluate the properties of these composites. Then, for modeling and prediction of hardness and electrical conductivity, a multi layer perceptron back propagation feed forward neural network was constructed to evaluate and compare the experimental calculated data to predicted values. It was found that, in a given sintering temperature of 875°C, the electrical conductivity increases as the sintering time increases and the amount of Al2O3 reinforcement decreases. Also, increasing of reinforcement amount and sintering time in a given sintering temperature of 875°C leads to a decrease in hardness. Furthermore, electrical conductivity and hardness of specimens have shown a consistency with predicted results of ANN. These trained values had an average error of 3% and 5% for electrical conductivity and hardness values, respectively
A Review on Social Anxiety Disorder, Effective Factors and Treatment
ABSTRACT Social anxiety disorder (SAD) is a type of anxiety disorders. It refers to a resistant fear in the individual. Fear of society, social interactions, and all situations in which both relational aspects and functional performances of the disordered person are involved. A person with social anxiety disorder does not lack social senses and a tendency to communicate with others, but the fear of possible humiliating situations, makes him to tend to social avoidance while he is aware of the fear and illogicality in his action. Many surveys are carried out in the field of treatment and reduction of SAD symptoms, especially in cognitive and metacognitive treatment. Cognitive treatment focuses on self-talk as one of the surveyed fields in SAD investigation. In fact, self-talk is a fruit of human cognitions that is revealed through talking or expressing one's own opinion about others, the world and individual's communications. Moreover, a study on the field revealed that cognitive treatment based on self-talk is useful in reducing social anxieties, and negative self-talks have a more important role than positive ones, thus, treatments should focus on elimination of negative thoughts more that establishing positive ones. Social anxiety disorder (SAD) is among the most prevalent mental disorders, and its prevalence rate is estimated to be 13%. Its obvious destructive role in social interactions of the individuals and their isolation and avoidance of positive and essential activities of life signifies the maladaptive nature of the disorder
Solitons in magneto-optic waveguides with Kudryashov’s law nonlinear refractive index for coupled system of generalized nonlinear Schrödinger’s equation using modified extended mapping method
In this work, we investigate the optical solitons and other waves through magneto-optic waveguides with Kudryashov’s law of nonlinear refractive index in the presence of chromatic dispersion and Hamiltonian-type perturbation factors using the modified extended mapping approach. Many classifications of solutions are established like bright solitons, dark solitons, singular solitons, singular periodic wave solutions, exponential wave solutions, rational wave, solutions, Weierstrass elliptic doubly periodic solutions, and Jacobi elliptic function solutions. Some of the extracted solutions are described graphically to provide their physical understanding of the acquired solutions
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