54 research outputs found
Transforming Controlled Duffing Oscillator to Optimization Schemes Using New Symmetry-Shifted G(t)-Polynomials
No full textThis work introduces and studies the important properties of a special class of new symmetry-shifted Gt-olynomials (NSSG). Such polynomials have a symmetry property over the interval [−2, 0], with Gn−2,00=−1nGn−2,0(−2). An explicit formulation of an NSSG operational matrixwas constructed, which served as a powerful tool for obtaining the desired numerical solutions. Then, a modified direct computational algorithm was suggested for solving the controlled Duffing oscillator problem. The idea behind the proposed algorithm is based on using symmetry basis functions, which are important and have real-world applications in physics and engineering. The original controlled Duffing oscillator problem was transformed into a nonlinear quadratic programming problem. Finally, numerical experiments are presented to validate our theoretical results. The numerical results emphasize that the modified proposed approach reaches the desired value of the performance index, with a few computations and with the minimum order of the NSSG basis function when compared with the other existing method, which is an important factor to consider when choosing the appropriate method in other mathematical and engineering applications
Operational Matrix of New Shifted Wavelet Functions for Solving Optimal Control Problem
No full textThis paper is devoted to proposing an approximate numerical algorithm based on the use of the state parameterization technique in order to find the solution to the optimal control problem (OCP). An explicit formula for new shifted wavelet (NSW) functions is constructed. A new formula that expresses the first-order derivative of the NSW in terms of their original NSW is established. The development of our suggested numerical algorithms begins with the extraction of a new operational matrix of derivative from this derivative formula. The expansion’s convergence study is performed in detail, and some illustrative examples of OCP are displayed. The proposed algorithm is compared with the exact one and some other methods in the literature. This confirms the accuracy and the high efficiency of the presented algorithm
Direct Iterative Algorithm for Solving Optimal Control Problems Using B-Spline Polynomials
Get PDFNew technique for achieving an approximate solution to optimal control problems (OCPs) is considered in this paper. The algorithm is based upon B-spline polynomials (BSPs) approximation with state parameterization method. An important property concerning the B-spline functions is first presented then it is utilized to propose a modified restarted technique to reduce the number of unknown parameters with fast convergence. The method is applied through four illustrative examples and is compared with other results
Optimization of WEDM Process Parameters for Machining of Friction-Stir-Welded 5754 Aluminum Alloy Using Box–Behnken Design of RSM
No full textPsychological health and its relationship to the concern for the future of parents of children with autism disorder
Get PDFThe nation cares about the health of its children and puts this attention in the forefront of its duties because the people do not rise and develop without individuals who are physically, mentally and psychologically healthy and his mental health is the land that is covered by the children and from it stems from their creations in the different aspects of life artistic and literary Social, scientific, cultural and other.The search aims to:-To identify the mental health of parents of children with autism disorder.-To identify the future concerns of parents of children with autism disorder.-To identify the relationship between mental health and the future concerns of parents of children with autism disorder.The researchers used the measure of mental health and the measure of anxiety of the futureThe research sample was the guardians of children with autism disorder (25). The main results of the research were:The anxiety is in a healthy state when it is at a normal level and this level can be known whether it is normal or not by comparing it to a mental health variable that has proven that the research sample is highly psychiatri
Studies in scientometrics II. The relation between source author and cited author populations
Get PDFUma sequência anual de Citation Indexes mantém um padrão de comportamento em muito semelhante a uma sequência de Source Indexes. Cinco anos do Source Index (1964-1968) foram considerados como suficientes para distinguir, entre os autores, as classes de transientes e permanentes, e três anos do Citation Index (1966-1968) para identificar referências a autores iniciando publicação no começo do período. O arquivo listou 640 autores, dos quais 381 estavam incluídos nos cinco Source Indexes e 442 nos três Citation Indexes, sendo 183 nomes comuns a ambas categorias de índices. Dos autores transientes que aparecem apenas em um único Source Index, 71% não são citados, 19% são transitoriamente citados e somente 10% parecem ser permanentes em citação.Um autor transiente tem cerca de 30% de chance de ser citado em qualquer ano. Do núcleo de 22 autores permanentes que publicam nos cinco anos registrados,19 são também citados em todos os três anos. É importante notar que esses mesmos 19 autores são também aqueles que continuam não apenas por um períodode 5 anos mas pelo período de 7 anos registrados noestudo anterior. Os autores permanentes do Sourcetendem a ser permanentes também em citação. Um grupo de 259 autores que são citados não aparece entre os autores-fonte. Desses, 80% são transientes e 20%são permanentes. Com a edição de novos dados de citação e de características de grupos de autores não incluídos no Source, os grupos demográficos são distribuídos nas seguintes categorias: a) transientes, b) permanentes que não fazem parte do núcleo, c) permanentes integrantes ao núcleo, d) permanentes que continuam a ser citados embora não mais publiquem,e) antigos transientes e f) novos permanentes.AbstractA sequence of annual Citation Indexes behaves in very much the same way as the sequence of Source Indexes. Five years o f Source Index were regarded (1964-1968) as sufficient to distinguish the transient and continuant classes amongst the authors,and three years o f the Citation Index (1966-1968) to pick up references to authors commencing publication at the begining of the period. The file listed 640 authors of which 381 were in the five Source Indexes and 442 in the three Citation Indexes with 183 names being common to both sets of index.O f the transient authors who appear in only a single Source Index 71% are uncited, 19% are transiently cited and only 10% seem to be continuants in citation. A transient author has about 30% chance of being cited in any year. Of the core continuant authors who publish in ali five years of record, 19 of the 22 are also cited in all the three years. It's worth noting that these 19 authors are also those who continue not merely for a five year span but for the seven years recorded in the previous study. Continuant source authors have astrong tendency to be continuants also in citation.A considerable group of 259 names in Citation Index do not appear amongst the source authors. Of the 259 names 80% are transiently cited and 20% are continuants. With the addition of new citation data and the characteristics oft he non-sourcegroups, not before detected, the demographic groups now become as: a) transients b) non-core continuants c) core continuants d) terminated continuants e) former transients f) newly recruited continuants
Evaluation of Surface Roughness and Material Removal Rate in End Milling of Complex Shape
No full textAbstract In this work, an attempt has been made to analyze the influence of various machining input parameters of CNC end milling process viz. cutting speed, feed rate and depth of cut on machining output variables (surface roughness and material removal rate) during machining complex shape of copper. Three different levels of input parameters were planned as per Taguchi's L 9 orthogonal array. The parameters are optimised from analysis of mean (ANOM). Analysis of variance (ANOVA) was employed to investigate the effect of machining parameters on the variables. Results of this study indicate that the depth of cut has the most significant effect on R a having percentage contribution of 71.06% followed by feed rate and cutting speed having percentage contribution of 23.22% and 2.12% respectively. For material removal rate, it is observed that the percentage contribution of feed rate is maximum i.e. 68.58% followed by depth of cut and cutting speed having percentage contribution of 22.13% and 7.52% respectively. Also, the results revealed that optimum combination of machining parameters which resulted in optimum value of the surface roughness is A 3 B 1 C 2 i.e. cutting speed of 6000 rpm, feed rate of 500 mm/tooth and depth of Cut of 0.06 mm. Similarly, optimum combination of machining parameters which resulted in optimum value of material removal rate is A 1 ,B 3 C 3 where the values for cutting speed, feed rate and depth of cut are 2000 rpm, 1500 mm/tooth and 0.08 mm respectively
Evaluation of Surface Roughness and Material Removal Rate in End Milling of Complex Shape
No full textNumerical Solution of Calculus of Variations by using the Second Chebyshev Wavelets
Get PDFIn this paper the second Chebyshev wavelets expansions with the operational matrix is applied for solving calculus of variational problems , with the aid of spectral method to reduce the variational problems in to a solution set of algebraic equations . Finally, numerical examples are present to show the validity and efficiency of the techniqu
A Novel Spectral Modified Pell Polynomials for Solving Singular Differential Equations
No full textThis paper studies the modified Pell polynomials. Some important properties of modified Pell polynomials are presented. An exact formula of modified Pell polynomials derivative in terms of modified Pell themselves is first derived with the proof and then a new relationship is constructed which relates the modified Pell polynomials expansion coefficients of a derivative in terms of their original expansion coefficients. An interesting new formula for the product operational matrix of modified Pell polynomials is also derived in this work. With modified Pell polynomials expansion scheme, the powers 1, x, …, xn are expressed in terms of such polynomials. The main goal of all presented formulas is to simplify the original equations and the determination of the coefficients of expansion based on modified Pell polynomials will be easy. Spectral techniques together with all the derived formulas of modified Pell polynomials are utilized to solve some singular initial value problems. Three test examples are solved in this work to illustrate the validity of the proposed method. The computational method is replaced by exact and explicit formulas. More accurate results are obtained than those presented by other existing methods in the literature
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