Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201A meshless numerical investigation based on the RBF-QR approach for elasticity problems115337910.22060/ajmc.2019.15990.1019ENMostafaAbbaszadehDepartment of Mathematics and Computer Science, Amirkabir University of Technology0000-0001-6954-3896MehdiDehghanDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)Journal Article20190113In the current research work, we present an improvement of meshless<br />boundary element method (MBEM) based on the shape functions of radial<br />basis functions-QR (RBF-QR) for solving the two-dimensional<br />elasticity problems. The MBEM has benefits of the boundary integral<br />equations (BIEs) to reduce the dimension of problem and the<br />meshless attributes of moving least squares (MLS) approximations.<br />Since the MLS shape functions don't have the delta<br />function property, applying boundary conditions is not simple. Here, we<br />propose the MBEM using RBF-QR to increase the accuracy and<br />efficiency of MBEM. To show the performance of the new technique,<br />the two-dimensional elasticity problems have been selected. We solve<br />the mentioned model on several irregular domains and report simulation results.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201The bimodal standard normal density and kurtosis1725304010.22060/ajmc.2018.3040ENJavadBehboodianDepartment of Statistics, School of Science, Shiraz University, ShirazMaryamSharafiDepartment of Statistics, School of Science, Shiraz University, ShirazZahraSajjadniaDepartment of Statistics, School of Science, Shiraz University, ShirazMazyarZarepourDepartment of Mathematics, Islamic Azad University, Shiraz Branch, Shiraz, Iran.Journal Article20180315In this article, first a density by the name "The bimodal standard normal density" is introduced and denoted by bΦ(z). Then, a dention for the kurtosis of bimodal densities relative to bΦ(z) is presented. Finally, to illustrate the introduced kurtosis, a few examples<br />are provided and a real data set is studied,too.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201(α,β)-Metrics with killing β of constant length2736303810.22060/ajmc.2018.3038ENTayebehTabatabaeifarAmirkabir universityBehzadNajafiDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)Journal Article20180309The class of (α,β)-metrics is a rich and important class of Finsler metrics, which is extensively studied. Here, we study (α,β)-metrics with Killing of constant length 1-form β and find a simplified formula for their Ricci curvatures. Then, we<br />show that if F=α+β+bfrac{β^2}{α} is an Einstein Finsler metric, then α is an Einstein Riemann metric.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201On Sobolev spaces and density theorems on Finsler manifolds3745303910.22060/ajmc.2018.3039ENBehroozBidabadDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)0000-0003-3993-4268AlirezaShahiFaculty of Mathematics and computer science, Amirkabir University of TechnologyJournal Article20180403Here, a natural extension of Sobolev spaces is defined for a Finsler structure $F$ and it is shown that the set of all real $C^{∞}$ functions with compact support on a forward geodesically complete Finsler manifold $(M, F)$, is dense in the extended Sobolev space $H_1^p (M)$.<br />As a consequence, the weak solutions $u$ of the Dirichlet equation $Δu=f$ can be approximated by $C^∞$ functions with compact support on $M$.<br />Moreover, let $W subset M$ be a regular domain with the $C^r$ boundary $partial W$, then the set of all real functions in $C^r (W) cap C^0 (overline W)$ is dense in $H_k^p (W)$, where $k≤r$. Finally, several examples are illustrated and sharpness of the inequality $k≤r$ is shown.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201A simple greedy approximation algorithm for the unit disk cover problem4755304410.22060/ajmc.2018.3044ENMahdiImanparastDepartment of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, IranSeyed NaserHashemiDepartment of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, IranJournal Article20180424Given a set P of n points in the plane, the unit disk cover problem, which is known as an NP-hard problem, seeks to find the minimum number of unit disks that can cover all points of P. In this paper, we present a new 4-approximation algorithm with running time O(n log n) for this problem. Our proposed algorithm uses a simple greedy approach and is easy to understand and implement.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201The complementary odd Weibull power series distribution: properties and applications5767372210.22060/ajmc.2019.15207.1015ENMehdiGoldoustDepartment of Mathematics, Behbahan Branch, Islamic Azad University, Behbahan, IranJournal Article20181029In this paper, a new four-parameters model called the complementary odd Weibull power<br />series (COWPS) distribution is defined and its properties are explored. This new distribution exhibits several new and well-known hazard rate shapes such as increasing, decreasing,<br />bathtub-shaped and J-shape hazard rate. Some of its mathematical properties are obtained<br />including moments, quantiles reliability, and moment generating functions. Maximum likelihood estimation method is used to estimate the vector of parameters. A simulation study<br />is presented to investigate the performance of the estimators. Finally, The usefulness of the<br />model has been demonstrated by applying it to a real-life dataset.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201A generalization of Marshall-Olkin bivariate Pareto model and its applications in shock and competing risk models6987312510.22060/ajmc.2018.14869.1012ENShirinShoaeeDepartment of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, Iran.EsmaeilKhorramDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)Journal Article20180802Statistical inference for extremes has been a subject of intensive research during the last years. In this paper, we generalize the Marshall-Olkin bivariate Pareto distribution. In this case, a new bivariate distribution is introduced by compounding the Pareto Type II and geometric distributions. This new bivariate distribution has natural interpretations and can be applied in fatal shock models or in competing risks models. We call the new proposed model Marshall-Olkin bivariate Pareto-geometric (MOBPG) distribution, and then investigate various properties of the new distribution. This model has five unknown parameters and the maximum likelihood estimators cannot be afforded in explicit structure. We suggest to use the EM algorithm to calculate the maximum likelihood estimators of the unknown parameters, and this structure is quite flexible.<br /> Also, Monte Carlo simulations are performed to investigate the effectiveness of the proposed algorithm. Finally, we analyze a real data set to investigate our purposes.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201The validity of a Thompson's problem for PSL(4,7)8994374610.22060/ajmc.2019.16174.1022ENBehroozKhosraviDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)CyrusKalantarpourDepartment of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, IranJournal Article20190421Let $pi_e(G)$ be the set of elements orders of $ G$. Also let $ s_n$ be the number of elements of order $n$ in $G $ and ${rm nse}(G)= lbrace s_nmid nin pi_e(G) rbrace $.<br />In this paper we prove that if $ G$ is a group such that ${rm nse}(G)= {rm nse}(rm PSL(4,7)) $, $19bigvert|G|$ and $19^2nmid|G|$, then $ Gcong rm PSL(4,7)$. As a consequence of this result it follows that Thompson's problem is satisfied for the simple group $rm PSL(4,7)$.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201A real-time decision support system for bridge management based on the rules generalized by CART decision tree and SMO algorithms95100304310.22060/ajmc.2018.3043ENShadiAbpeykarDepartment of Computer ScienceMehdiGhateeDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)Journal Article20180401Under dynamic conditions on bridges, we need a real-time management. To this end, this paper presents a rule-based decision support system in which the necessary rules are extracted from simulation results made by Aimsun traffic micro-simulation software. Then, these rules are generalized by the aid of fuzzy rule generation algorithms. Then, they are trained by a set of supervised and the unsupervised learning algorithms to get an ability to make decision in real cases. As a pilot case study, Nasr Bridge in Tehran is simulated in Aimsun and WEKA data mining software is used to execute the learning algorithms. Based on this experiment, the accuracy of the supervised algorithms to generalize the rules is greater than 80%. In addition, CART decision tree and sequential minimal optimization (SMO) provides 100% accuracy for normal data and these algorithms are so reliable for crisis management on bridge. This means that, it is possible to use such machine learning methods to manage bridges in the real-time conditions.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201Statistical and fuzzy clustering methods and their application to clustering Pprovinces of Iraq based on agricultural products101112324510.22060/ajmc.2019.14873.1013ENSeyed MahmoudTaheriSchool of Engineering Science, College of Engineering, University of TehranIsraaAtiyahFaculty of Mathematics and Computer Science, Amirkabir University of Technology, TehranJournal Article20180821The important approaches to statistical and fuzzy clustering are reviewed and compared, and their applications to an agricultural problem based on a real-world data are investigated. The methods employed in this study includes some hierarchical clustering and non-hierarchical clustering methods and fuzzy c-means method. As a case study, these methods are then applied to cluster 15 provinces of Iraq based on some agricultural crops. Finally, a comparative and evaluation study of different statistical and fuzzy clustering methods is performed. The obtained results showed that, based on the Silhouette criterion and Xie-Beni index, fuzzy c-means method is the best one among all reviewed methods.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201Smartphone-based system for driver anger scale estimation using neural network on continuous wavelet transformation113124328710.22060/ajmc.2019.15327.1016ENHamid RezaEftekhariDepartment of Computer engineering, Faculty of Engineering, Malayer University, Hamedan, IranJournal Article20181124Monitoring of the driver decreases accidents by reducing the risky behaviors and causes decreases the fuel consumption by preventing aggressive behavior. But this monitoring is costly due to built-in equipment. In this study, we propose a new model to recognize driving behavior by smartphone data without any extra equipment in the vehicles which is an important added value for smartphones. This recognition process is done in this paper based on the continuous wavelet transformation on accelerometer data. Then these patterns are fed to multilayer perceptron neural network to extend the information extracted from the corresponding features. Also the magnetometer sensor is used to detect the maneuvers through the driving period. Results show the accuracy of the proposed system is near 80% for pattern recognition. Driver scale based on a standard questionnaires regarding to driver angry scale (DAS), is also estimated by the proposed multilayer perceptron neural network with 3.7% errors in the average.Amirkabir University of TechnologyAUT Journal of Mathematics and Computing1120200201Adopting GRASP to solve a novel model for bus timetabling problem with minimum transfer and fruitless waiting times125134332310.22060/ajmc.2019.15497.1018ENJavadZamani KafshaniAmirkabir University of TechnologySeyyed AliMirhassaniDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)FarnazHooshmandDepartment of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)Journal Article20181122This paper addresses a variant of bus timetabling problem assuming that travel times changes dynamically over the planning horizon. In addition to minimizing the transfer waiting time, another objective, namely minimizing the fruitless waiting time, is introduced in this paper as a new realistic objective. First, the problem is formulated as a mixed integer linear programming model. Then, since commercial solvers become inefficient to solve moderate and large sized instances of the problem (due to the NP-hardness), a GRASP heuristic algorithm is developed. Computational experiments over a variety of random instances verify the performance of the proposed method.