Research Article
Saeed Nezhadhosein; Reza Ghanbari; Khatere Ghorbani-Moghadam
Abstract
In this paper, we solve a class of nonlinear optimal control problems using a hybrid genetic algorithm (HGA) and a direct method based on the Haar wavelets where the performance index is Bolza-form and the dynamic system is linear. First, we change the problem by using HWs to a static ...
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In this paper, we solve a class of nonlinear optimal control problems using a hybrid genetic algorithm (HGA) and a direct method based on the Haar wavelets where the performance index is Bolza-form and the dynamic system is linear. First, we change the problem by using HWs to a static optimization problem in which the decision variables are the unknown coefficients of the state and control variables in the Haar series. Next, we apply HGA with a local search for higher power of GA in investigating the search space for solving optimization problems. Finally, we give some examples to illustrate the high accuracy of the proposed method.
Research Article
Zeinab Saeidian; Maryam Mahmoudoghli
Abstract
The Proximal Stochastic Average Gradient (Prox-SAG+) is a primary method used for solving optimization problems that contain the sum of two convex functions. This kind of problem usually arises in machine learning, which utilizes a large amount of data to create component functions from a dataset. ...
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The Proximal Stochastic Average Gradient (Prox-SAG+) is a primary method used for solving optimization problems that contain the sum of two convex functions. This kind of problem usually arises in machine learning, which utilizes a large amount of data to create component functions from a dataset. A proximal operation is applied to obtain the optimal value due to its appropriate properties. The Prox-SAG+ algorithm is faster than some other methods and has a simpler algorithm than previous ones. Moreover, using this specific operator can help to reassure that the achieved result is optimal. Additionally, it has been proven that the proposed method has an approximately geometric rate of convergence. Implementing the proposed operator makes the method more practical than other algorithms found in the literature. Numerical analysis also confirms the efficiency of the proposed scheme.
Research Article
Hadis Ahmadian Yazdi; Seyed Javad Seyyed Mahdavi Chabok; Maryam KheirAbadi
Abstract
In recent decades, the amount and variety of data have grown rapidly. As a result, data storage, compression, and analysis have become critical subjects in data mining and machine learning. It is essential to achieve accurate compression without losing important data in the process. Therefore, this ...
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In recent decades, the amount and variety of data have grown rapidly. As a result, data storage, compression, and analysis have become critical subjects in data mining and machine learning. It is essential to achieve accurate compression without losing important data in the process. Therefore, this work proposes an effective data compression method for recommender systems based on the attention mechanism. The proposed method performs data compression on two levels: features and records. It is time-aware and based on time windows, taking into account users' activity and preventing the loss of important data. The resulting technique can be efficiently utilized for deep networks, where the amount of data is a significant challenge. Experimental results demonstrate that this technique not only reduces the amount of data and processing time but also achieves acceptable accuracy.
Research Article
Rasool Hatamian Joghali
Abstract
In 2010, Alvarez et al. proposed an algorithm for morphological snakes that could detect objects whose edges consist of convex sets and polygonal edges. However, the algorithm may not detect the boundary well if the edges of an object contain a convex set or if there are several separated ...
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In 2010, Alvarez et al. proposed an algorithm for morphological snakes that could detect objects whose edges consist of convex sets and polygonal edges. However, the algorithm may not detect the boundary well if the edges of an object contain a convex set or if there are several separated objects in an image. In this paper, we present two optimal sub-algorithms that are modifications to the Alvarez et al. algorithm. Our algorithms provide optimal edge detection for images and we present examples to demonstrate their effectiveness.
Research Article
Mohammad Hossein Rahmani Doust; Mohammad Nasser Modoodi; Arash Mowdoudi
Abstract
Mathematical modeling has been a significant tool in biological sciences for several decades. Modern agricultural practices have had numerous effects on different aspects of ecosystems, particularly on animal populations. This research focuses on road collisions involving wildlife and emphasizes the ...
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Mathematical modeling has been a significant tool in biological sciences for several decades. Modern agricultural practices have had numerous effects on different aspects of ecosystems, particularly on animal populations. This research focuses on road collisions involving wildlife and emphasizes the effects of agricultural and non-agricultural surrounding lands. Using non-parametric Mann-Whitney U and Spearman's Rank tests, as well as SPSS software, the study found that the highest number of wildlife deaths, especially for mammals, birds, and reptiles, occurred in areas surrounded by natural regions (non-agricultural lands). Furthermore, the study found that the number of casualties was highest in the middle month of spring and those morning observations resulted in more collisions than evening ones. The correlation coefficients confirmed a significant relationship between the frequency of accidents and the type of surrounding landscape. Additionally, the researchers proposed a logistic mathematical model to investigate the relationship between animal losses and vehicle collisions. After identifying the equilibrium points, the study analyzed the solution behavior around these points.
Research Article
Sajad Sohrabi Hesan; Freydoon Rahbarnia; Mostafa Tavakolli
Abstract
Given any graph G, its square graph G^2 has the same vertex set as G, with two vertices adjacent in G^2 whenever they are at distance 1 or 2 in G. The Cartesian product of graphs G and H is denoted by G□ H. One of the most studied NP-hard problems is the graph coloring ...
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Given any graph G, its square graph G^2 has the same vertex set as G, with two vertices adjacent in G^2 whenever they are at distance 1 or 2 in G. The Cartesian product of graphs G and H is denoted by G□ H. One of the most studied NP-hard problems is the graph coloring problem. A method such as Genetic Algorithm (GA) is highly preferred to solve the Graph Coloring problem by researchers for many years. In this paper, we use the graph product approach to this problem. In fact, we prove that X((D(m',n')□D(m,n))^2)<= 10 for m,n => 3, where D(m, n) is the graph obtained by joining a vertex of the cycle C_m to a vertex of degree one of the paths P_n and X(G) is the chromatic number of the graph $G$.
