ORIGINAL_ARTICLE
A meshless numerical investigation based on the RBF-QR approach for elasticity problems
In the current research work, we present an improvement of meshlessboundary element method (MBEM) based on the shape functions of radialbasis functions-QR (RBF-QR) for solving the two-dimensionalelasticity 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 RBF-QR to increase the accuracy andefficiency of MBEM. To show the performance of the new technique,the two-dimensional elasticity problems have been selected. We solvethe mentioned model on several irregular domains and report simulation results.
https://ajmc.aut.ac.ir/article_3379_ffbd2283d5745c4b85031e1eaf021000.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
1
15
10.22060/ajmc.2019.15990.1019
Boundary element method
RBF-QR approach
Two-dimensional elasticity problems
Meshless Method
Mostafa
Abbaszadeh
m.abbaszadeh@aut.ac.ir
true
1
Department of Mathematics and Computer Science, Amirkabir University of Technology
Department of Mathematics and Computer Science, Amirkabir University of Technology
Department of Mathematics and Computer Science, Amirkabir University of Technology
LEAD_AUTHOR
Mehdi
Dehghan
mdehghan@aut.ac.ir
true
2
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
AUTHOR
ORIGINAL_ARTICLE
The bimodal standard normal density and kurtosis
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.
https://ajmc.aut.ac.ir/article_3040_cba0b169b1d9096e97113d867cacd623.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
17
25
10.22060/ajmc.2018.3040
normal density
mixed normal density
bimodal standard normal density
kurtosis of a bimodal density
Javad
Behboodian
behboodian@shirazu.ac.ir
true
1
Department of Statistics, School of Science, Shiraz University, Shiraz
Department of Statistics, School of Science, Shiraz University, Shiraz
Department of Statistics, School of Science, Shiraz University, Shiraz
AUTHOR
Maryam
Sharafi
msharafi@shirazu.ac.ir
true
2
Department of Statistics, School of Science, Shiraz University, Shiraz
Department of Statistics, School of Science, Shiraz University, Shiraz
Department of Statistics, School of Science, Shiraz University, Shiraz
AUTHOR
Zahra
Sajjadnia
sajjadnia@shirazu.ac.ir
true
3
Department of Statistics, School of Science, Shiraz University, Shiraz
Department of Statistics, School of Science, Shiraz University, Shiraz
Department of Statistics, School of Science, Shiraz University, Shiraz
LEAD_AUTHOR
Mazyar
Zarepour
mazyar_z@hotmail.com
true
4
Department of Mathematics, Islamic Azad University, Shiraz Branch, Shiraz, Iran.
Department of Mathematics, Islamic Azad University, Shiraz Branch, Shiraz, Iran.
Department of Mathematics, Islamic Azad University, Shiraz Branch, Shiraz, Iran.
AUTHOR
ORIGINAL_ARTICLE
(α,β)-Metrics with killing β of constant length
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 1-form β and find a simplified formula for their Ricci curvatures. Then, weshow that if F=α+β+b\frac{β^2}{α} is an Einstein Finsler metric, then α is an Einstein Riemann metric.
https://ajmc.aut.ac.ir/article_3038_ec3b89402c7338eacb774d68fb1a1cb0.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
27
36
10.22060/ajmc.2018.3038
Finsler metric
(α,β)-metric
Einstein manifold
Tayebeh
Tabatabaeifar
t.tabaee@gmail.com
true
1
Amirkabir university
Amirkabir university
Amirkabir university
AUTHOR
Behzad
Najafi
behzad.najafi@aut.ac.ir
true
2
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
LEAD_AUTHOR
ORIGINAL_ARTICLE
On Sobolev spaces and density theorems on Finsler manifolds
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.
https://ajmc.aut.ac.ir/article_3039_ef823186580a9c859620d42c8543c999.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
37
45
10.22060/ajmc.2018.3039
Density theorem
Sobolev spaces
Dirichlet problem
Finsler space
Behrooz
Bidabad
bidabad@aut.ac.ir
true
1
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
LEAD_AUTHOR
Alireza
Shahi
alirezashahi@aut.ac.ir
true
2
Faculty of Mathematics and computer science, Amirkabir University of Technology
Faculty of Mathematics and computer science, Amirkabir University of Technology
Faculty of Mathematics and computer science, Amirkabir University of Technology
AUTHOR
ORIGINAL_ARTICLE
A simple greedy approximation algorithm for the unit disk cover problem
Given 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.
https://ajmc.aut.ac.ir/article_3044_69fd7125903ed84f45ff4a2b2a419779.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
47
55
10.22060/ajmc.2018.3044
computational geometry
approximation algorithms
unit disk cover problem
facility location
Mahdi
Imanparast
m.imanparast@aut.ac.ir
true
1
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
AUTHOR
Seyed Naser
Hashemi
nhashemi@aut.ac.ir
true
2
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
LEAD_AUTHOR
ORIGINAL_ARTICLE
The complementary odd Weibull power series distribution: properties and applications
In this paper, a new four-parameters model called the complementary odd Weibull powerseries (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,bathtub-shaped and J-shape 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 real-life dataset.
https://ajmc.aut.ac.ir/article_3722_1be02552deb40e99ef41e3344ca6aa8e.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
57
67
10.22060/ajmc.2019.15207.1015
Compound distribution
Maximum Likelihood Estimation
Power series distribution
Odd Weibull distribution
Mehdi
Goldoust
mehdigoldust@yahoo.com
true
1
Department of Mathematics, Behbahan Branch, Islamic Azad University, Behbahan, Iran
Department of Mathematics, Behbahan Branch, Islamic Azad University, Behbahan, Iran
Department of Mathematics, Behbahan Branch, Islamic Azad University, Behbahan, Iran
LEAD_AUTHOR
ORIGINAL_ARTICLE
A generalization of Marshall-Olkin bivariate Pareto model and its applications in shock and competing risk models
Statistical 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. 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.
https://ajmc.aut.ac.ir/article_3125_8385d20bf3dcd48513f53a4a97c11981.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
69
87
10.22060/ajmc.2018.14869.1012
Bivariate model
Competing risk model
Expectation-Maximization algorithm
Pareto Type II distribution
Shock model
Shirin
Shoaee
shirin_shoaee@aut.ac.ir
true
1
Department of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, Iran.
Department of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, Iran.
Department of Statistics, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, Iran.
LEAD_AUTHOR
Esmaeil
Khorram
eskhor@aut.ac.ir
true
2
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
AUTHOR
ORIGINAL_ARTICLE
The validity of a Thompson's problem for PSL(4,7)
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)) $, $19bigvert|G|$ 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 $rm PSL(4,7)$.
https://ajmc.aut.ac.ir/article_3746_c15795a34e3e77400bdbc8563d65144d.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
89
94
10.22060/ajmc.2019.16174.1022
Thompson's problem
Characterization
Number of elements of same order
Projective special linear group
Behrooz
Khosravi
bkhosravi@aut.ac.ir
true
1
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
LEAD_AUTHOR
Cyrus
Kalantarpour
siruspoly@gmail.com
true
2
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran
AUTHOR
ORIGINAL_ARTICLE
A real-time decision support system for bridge management based on the rules generalized by CART decision tree and SMO algorithms
Under 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.
https://ajmc.aut.ac.ir/article_3043_5969ea2b069b3fd8d1e298c8a6383f87.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
95
100
10.22060/ajmc.2018.3043
Intelligent Transportation Systems
Knowledge Extraction
Learning Algorithms
Traffic Simulators
Fuzzy Rule Generation Algorithm
Shadi
Abpeykar
shadi.a@aut.ac.ir
true
1
Department of Computer Science
Department of Computer Science
Department of Computer Science
AUTHOR
Mehdi
Ghatee
ghatee@aut.ac.ir
true
2
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
LEAD_AUTHOR
ORIGINAL_ARTICLE
Statistical and fuzzy clustering methods and their application to clustering Pprovinces of Iraq based on agricultural products
The 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.
https://ajmc.aut.ac.ir/article_3245_a255154ebe44780b879781a7e0ee6123.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
101
112
10.22060/ajmc.2019.14873.1013
Hierarchical Clustering
Non-Hierarchical Clustering
Fuzzy C-Means Clustering
Seyed Mahmoud
Taheri
sm_taheri@ut.ac.ir
true
1
School of Engineering Science, College of Engineering, University of Tehran
School of Engineering Science, College of Engineering, University of Tehran
School of Engineering Science, College of Engineering, University of Tehran
LEAD_AUTHOR
Israa
Atiyah
israa.zad@aut.ac.ir
true
2
Faculty of Mathematics and Computer Science, Amirkabir University of Technology, Tehran
Faculty of Mathematics and Computer Science, Amirkabir University of Technology, Tehran
Faculty of Mathematics and Computer Science, Amirkabir University of Technology, Tehran
AUTHOR
ORIGINAL_ARTICLE
Smartphone-based system for driver anger scale estimation using neural network on continuous wavelet transformation
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 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.
https://ajmc.aut.ac.ir/article_3287_964f797962c44f02c009a4313255f902.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
113
124
10.22060/ajmc.2019.15327.1016
Risky behavior
Driver monitoring
smartphone
Wavelet transformation
Multilayer perceptron neural network
Hamid Reza
Eftekhari
eftekhari@malayeru.ac.ir
true
1
Department of Computer engineering, Faculty of Engineering, Malayer University, Hamedan, Iran
Department of Computer engineering, Faculty of Engineering, Malayer University, Hamedan, Iran
Department of Computer engineering, Faculty of Engineering, Malayer University, Hamedan, Iran
LEAD_AUTHOR
ORIGINAL_ARTICLE
Adopting GRASP to solve a novel model for bus timetabling problem with minimum transfer and fruitless waiting times
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 NP-hardness), a GRASP heuristic algorithm is developed. Computational experiments over a variety of random instances verify the performance of the proposed method.
https://ajmc.aut.ac.ir/article_3323_85cc256ebddca4a51b227d38698683da.pdf
2020-02-01T11:23:20
2021-04-16T11:23:20
125
134
10.22060/ajmc.2019.15497.1018
Bus timetabling
Dynamic travel time
Transfer waiting time
Fruitless waiting time
GRASP
Javad
Zamani Kafshani
j.zamani@aut.ac.ir
true
1
Amirkabir University of Technology
Amirkabir University of Technology
Amirkabir University of Technology
AUTHOR
Seyyed Ali
Mirhassani
a_mirhassani@aut.ac.ir
true
2
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
LEAD_AUTHOR
Farnaz
Hooshmand
f.hooshmand.khaligh@aut.ac.ir
true
3
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
Department of Mathematics and Computer Science, Amirkabir University of Technology (Tehran Polytechnic)
AUTHOR