2020
1
1
0
134
1

A meshless numerical investigation based on the RBFQR approach for elasticity problems
https://ajmc.aut.ac.ir/article_3379.html
10.22060/ajmc.2019.15990.1019
1
In the current research work, we present an improvement of meshlessboundary element method (MBEM) based on the shape functions of radialbasis functionsQR (RBFQR) for solving the twodimensionalelasticity problems. The MBEM has benefits of the boundary integralequations (BIEs) to reduce the dimension of problem and themeshless attributes of moving least squares (MLS) approximations.Since the MLS shape functions don't have the deltafunction property, applying boundary conditions is not simple. Here, wepropose the MBEM using RBFQR to increase the accuracy andefficiency of MBEM. To show the performance of the new technique,the twodimensional elasticity problems have been selected. We solvethe mentioned model on several irregular domains and report simulation results.
0

1
15


Mostafa
Abbaszadeh
Department of Mathematics and Computer Science, Amirkabir University of Technology
Iran
m.abbaszadeh@aut.ac.ir


Mehdi
Dehghan
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
mdehghan@aut.ac.ir
Boundary element method
RBFQR approach
Twodimensional elasticity problems
Meshless Method
1

The bimodal standard normal density and kurtosis
https://ajmc.aut.ac.ir/article_3040.html
10.22060/ajmc.2018.3040
1
In 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 examplesare provided and a real data set is studied,too.
0

17
25


Javad
Behboodian
Department of Statistics, School of Science, Shiraz University, Shiraz
Iran
behboodian@shirazu.ac.ir


Maryam
Sharafi
Department of Statistics, School of Science, Shiraz University, Shiraz
Iran
msharafi@shirazu.ac.ir


Zahra
Sajjadnia
Department of Statistics, School of Science, Shiraz University, Shiraz
Iran
sajjadnia@shirazu.ac.ir


Mazyar
Zarepour
Department of Mathematics, Islamic Azad University, Shiraz Branch, Shiraz, Iran.
Iran
mazyar_z@hotmail.com
normal density
mixed normal density
bimodal standard normal density
kurtosis of a bimodal density
1

(α,β)Metrics with killing β of constant length
https://ajmc.aut.ac.ir/article_3038.html
10.22060/ajmc.2018.3038
1
The 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 1form β and find a simplified formula for their Ricci curvatures. Then, weshow that if F=α+β+bfrac{β^2}{α} is an Einstein Finsler metric, then α is an Einstein Riemann metric.
0

27
36


Tayebeh
Tabatabaeifar
Amirkabir university
Iran
t.tabaee@gmail.com


Behzad
Najafi
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
behzad.najafi@aut.ac.ir
Finsler metric
(α,β)metric
Einstein manifold
1

On Sobolev spaces and density theorems on Finsler manifolds
https://ajmc.aut.ac.ir/article_3039.html
10.22060/ajmc.2018.3039
1
Here, 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 $H_1^p (M)$.As a consequence, the weak solutions $u$ of the Dirichlet equation $Δu=f$ can be approximated by $C^∞$ functions with compact support on $M$.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.
0

37
45


Behrooz
Bidabad
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
bidabad@aut.ac.ir


Alireza
Shahi
Faculty of Mathematics and computer science, Amirkabir University of Technology
Iran
alirezashahi@aut.ac.ir
Density theorem
Sobolev spaces
Dirichlet problem
Finsler space
1

A simple greedy approximation algorithm for the unit disk cover problem
https://ajmc.aut.ac.ir/article_3044.html
10.22060/ajmc.2018.3044
1
Given a set P of n points in the plane, the unit disk cover problem, which is known as an NPhard problem, seeks to find the minimum number of unit disks that can cover all points of P. In this paper, we present a new 4approximation 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.
0

47
55


Mahdi
Imanparast
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Iran
m.imanparast@aut.ac.ir


Seyed Naser
Hashemi
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Iran
nhashemi@aut.ac.ir
computational geometry
approximation algorithms
unit disk cover problem
facility location
1

The complementary odd Weibull power series distribution: properties and applications
https://ajmc.aut.ac.ir/article_3722.html
10.22060/ajmc.2019.15207.1015
1
In this paper, a new fourparameters model called the complementary odd Weibull powerseries (COWPS) distribution is defined and its properties are explored. This new distribution exhibits several new and wellknown hazard rate shapes such as increasing, decreasing,bathtubshaped and Jshape hazard rate. Some of its mathematical properties are obtainedincluding moments, quantiles reliability, and moment generating functions. Maximum likelihood estimation method is used to estimate the vector of parameters. A simulation studyis presented to investigate the performance of the estimators. Finally, The usefulness of themodel has been demonstrated by applying it to a reallife dataset.
0

57
67


Mehdi
Goldoust
Department of Mathematics, Behbahan Branch, Islamic Azad University, Behbahan, Iran
Iran
mehdigoldust@yahoo.com
Compound distribution
Maximum Likelihood Estimation
Power series distribution
Odd Weibull distribution
1

A generalization of MarshallOlkin bivariate Pareto model and its applications in shock and competing risk models
https://ajmc.aut.ac.ir/article_3125.html
10.22060/ajmc.2018.14869.1012
1
Statistical inference for extremes has been a subject of intensive research during the last years. In this paper, we generalize the MarshallOlkin 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 MarshallOlkin bivariate Paretogeometric (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. 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.
0

69
87


Shirin
Shoaee
Department of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, Iran.
Iran
shirin_shoaee@aut.ac.ir


Esmaeil
Khorram
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
eskhor@aut.ac.ir
Bivariate model
Competing risk model
ExpectationMaximization algorithm
Pareto Type II distribution
Shock model
1

The validity of a Thompson's problem for PSL(4,7)
https://ajmc.aut.ac.ir/article_3746.html
10.22060/ajmc.2019.16174.1022
1
Let $pi_e(G)$ 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 $.In this paper we prove that if $ G$ is a group such that ${rm nse}(G)= {rm nse}(rm PSL(4,7)) $, $19bigvertG$ and $19^2nmidG$, then $ Gcong rm PSL(4,7)$. As a consequence of this result it follows that Thompson's problem is satisfied for the simple group $rm PSL(4,7)$.
0

89
94


Behrooz
Khosravi
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
bkhosravi@aut.ac.ir


Cyrus
Kalantarpour
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Iran
siruspoly@gmail.com
Thompson's problem
Characterization
Number of elements of same order
Projective special linear group
1

A realtime decision support system for bridge management based on the rules generalized by CART decision tree and SMO algorithms
https://ajmc.aut.ac.ir/article_3043.html
10.22060/ajmc.2018.3043
1
Under dynamic conditions on bridges, we need a realtime management. To this end, this paper presents a rulebased decision support system in which the necessary rules are extracted from simulation results made by Aimsun traffic microsimulation 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 realtime conditions.
0

95
100


Shadi
Abpeykar
Department of Computer Science
Iran
shadi.a@aut.ac.ir


Mehdi
Ghatee
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
ghatee@aut.ac.ir
Intelligent Transportation Systems
Knowledge Extraction
Learning Algorithms
Traffic Simulators
Fuzzy Rule Generation Algorithm
1

Statistical and fuzzy clustering methods and their application to clustering Pprovinces of Iraq based on agricultural products
https://ajmc.aut.ac.ir/article_3245.html
10.22060/ajmc.2019.14873.1013
1
The important approaches to statistical and fuzzy clustering are reviewed and compared, and their applications to an agricultural problem based on a realworld data are investigated. The methods employed in this study includes some hierarchical clustering and nonhierarchical clustering methods and fuzzy cmeans 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 XieBeni index, fuzzy cmeans method is the best one among all reviewed methods.
0

101
112


Seyed Mahmoud
Taheri
School of Engineering Science, College of Engineering, University of Tehran
Iran
sm_taheri@ut.ac.ir


Israa
Atiyah
Faculty of Mathematics and Computer Science, Amirkabir University of Technology, Tehran
Iraq
israa.zad@aut.ac.ir
Hierarchical Clustering
NonHierarchical Clustering
Fuzzy CMeans Clustering
1

Smartphonebased system for driver anger scale estimation using neural network on continuous wavelet transformation
https://ajmc.aut.ac.ir/article_3287.html
10.22060/ajmc.2019.15327.1016
1
Monitoring 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 builtin 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.
0

113
124


Hamid Reza
Eftekhari
Department of Computer engineering, Faculty of Engineering, Malayer University, Hamedan, Iran
Iran
eftekhari@malayeru.ac.ir
Risky behavior
Driver monitoring
smartphone
Wavelet transformation
Multilayer perceptron neural network
1

Adopting GRASP to solve a novel model for bus timetabling problem with minimum transfer and fruitless waiting times
https://ajmc.aut.ac.ir/article_3323.html
10.22060/ajmc.2019.15497.1018
1
This 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 NPhardness), a GRASP heuristic algorithm is developed. Computational experiments over a variety of random instances verify the performance of the proposed method.
0

125
134


Javad
Zamani Kafshani
Amirkabir University of Technology
Iran
j.zamani@aut.ac.ir


Seyyed Ali
Mirhassani
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
a_mirhassani@aut.ac.ir


Farnaz
Hooshmand
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Iran
f.hooshmand.khaligh@aut.ac.ir
Bus timetabling
Dynamic travel time
Transfer waiting time
Fruitless waiting time
GRASP