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Issue Info: 
  • Year: 

    2023
  • Volume: 

    1
  • Issue: 

    1
  • Pages: 

    116-128
Measures: 
  • Citations: 

    0
  • Views: 

    28
  • Downloads: 

    0
Abstract: 

Facial skin segmentation plays an important role in applications such as identification, facial expression analysis, facial animation, and skin disease analysis. Clustering is one of the most common methods for image segmentation. In this paper, a new hybrid method based on Quantum Particle Swarm Optimization and Grey Wolf Optimization is presented to optimize the performance of the K-Means clustering. By Combination of two Algorithms, the exploitation performance of the QPSO Algorithm is improved by the exploration capability of the GWO Algorithm. To measure the similarity, four distance criteria including Euclidean, Minkowski,  Mahalanobis, and City-Block distances have been used to optimize the K-Means Algorithm. The proposed method has a better performance in segmentation and convergence speed compared to other meta-heuristic Algorithms such as Genetic Algorithm, GWO, PSO, QPSO, Bat Optimization, Crow Search Algorithm. The experimental results show that Minkowski distance has a better performance in calculating similarity and optimization of K-Means Algorithm. Based on the obtained results, the proposed method ensures the achievement of the optimal solution and prevents the problem from falling to a local minimum.

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Issue Info: 
  • Year: 

    2020
  • Volume: 

    50
  • Issue: 

    1 (91)
  • Pages: 

    269-281
Measures: 
  • Citations: 

    0
  • Views: 

    297
  • Downloads: 

    0
Abstract: 

Nowadays, speech enhancement has become one of the most important issues in signal processing. Noise reduction such that it does not disturb the original signal is an important challenge in speech enhancement. In this paper, we have proposed a new hybrid two-stage method for speech enhancement. In the proposed method, noisy speech signal is enhanced using perceptuallymotivated Bayesian approach in the first stage. Then, the signal is decomposed into sub-bands using wavelet packet decomposition. In the second stage, each sub-band signal is enhanced using NNESE method. Hyperparameters of NNESE is optimized using QPSO metaheuristic. Finally, all enhanced sub-band signals are combined together using wavelet packet reconstruction. Proposed method is better than others in terms of PESQ and Segmental SNR criteria over a subset of TIMIT speech database polluted by Noisex-92 noise database.

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Issue Info: 
  • Year: 

    2020
  • Volume: 

    16
  • Issue: 

    2
  • Pages: 

    146-152
Measures: 
  • Citations: 

    0
  • Views: 

    167
  • Downloads: 

    118
Abstract: 

This paper describes the synthesis of digitally excited pencil/flat top dual beams simultaneously in a linear antenna array constructed of isotropic elements. The objective is to generate a pencil/flat top beam pair using the excitations generated by the evolutionary Algorithms. Both the beams share common variable discrete amplitude excitations and differ in variable discrete phase excitations. This synthesis is treated as a multi-objective optimization problem and is handled by Quantum Particle Swarm Optimization Algorithm duly controlling the fitness functions. These functions include many of the radiation pattern parameters like side lobe level, half power beam width and beam width at the side lobe level in both the beams along with the ripple in the flat top band of flat top beam. In addition to it, the dynamic range ratio of the amplitudes excitations is set below a certain level to diminish the mutual coupling effects in the array. Two sets of experiments are conducted and the effectiveness of this Algorithm is proved by comparing it with various versions of swarm optimization Algorithms.

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Author(s): 

Azimi Milad | Jahan Morteza

Issue Info: 
  • Year: 

    2024
  • Volume: 

    13
  • Issue: 

    25
  • Pages: 

    65-81
Measures: 
  • Citations: 

    0
  • Views: 

    22
  • Downloads: 

    0
Abstract: 

This study focuses on the investigation of intelligent form-finding and vibration analysis of a triangular polyhedral tensegrity that is enclosed within a sphere and subjected to external loads. The nonlinear dynamic equations of the system are derived using the Lagrangian approach and the finite element method. The proposed form-finding approach, which is based on a basic genetic Algorithm, can determine regular or irregular tensegrity shapes without dimensional constraints. Stable tensegrity structures are generated from random configurations and based on defined constraints (nodes located on the sphere, parallelism, and area of upper and lower surfaces), and shape finding is performed using the fitness function of the genetic Algorithm and multi-objective optimization goals. The genetic Algorithm's efficacy in determining the shape of structures with unpredictable configurations is evaluated in two distinct scenarios: one involving a known connection matrix and the other involving fixed or random member positions (struts and cables). The shapes obtained from the Algorithm suggested in this study are validated using the force density approach, and their vibration characteristics are examined. The findings of the comparative study demonstrate the efficacy of the proposed methodology in determining the vibrational behavior of tensegrity structures through the utilization of intelligent shape seeking techniques.

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Author(s): 

Siasar H. | SALARI A.

Issue Info: 
  • Year: 

    2022
  • Volume: 

    15
  • Issue: 

    5
  • Pages: 

    1006-1017
Measures: 
  • Citations: 

    0
  • Views: 

    130
  • Downloads: 

    0
Abstract: 

Increasing population and food demand, disproportionate cultivation and annual production of various agricultural products with market needs and low productivity of the agricultural sector and the loss of water and soil resources have made it necessary to determine and implement the country's optimal cropping pattern. In this study, due to the limitations and problems of classical methods in order to reduce processing time and improve the quality of solutions, the Multi-Objective Chaotic Particle Swarm Optimization was used to determine the optimal cultivation pattern of Sistan plain in optimal conditions and deficit irrigation. The results of the Multi-Objective Chaotic Particle Swarm Optimization for the dominant cultures in the region showed that the current cropping pattern of the region is not optimal and with the implementation of the proposed model, the profit per unit area under cultivation will increase. The results of application of deficit irrigation during different growing periods of wheat, barley, alfalfa, sorghum, watermelon and grapes showed that applying deficit irrigation in this plain is not a good strategy and therefore only a full irrigation strategy is recommended. The results of sensitivity analysis of the model showed that at low prices, farmers reaction is less and at higher prices more reaction to price changes and with increasing prices, the program efficiency is lower.

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Issue Info: 
  • Year: 

    2023
  • Volume: 

    13
  • Issue: 

    52
  • Pages: 

    85-97
Measures: 
  • Citations: 

    0
  • Views: 

    80
  • Downloads: 

    8
Abstract: 

One of the basic topics in hydrological and river engineering studies is flood routing.Flood flooding is common in multi-tributary rivers and rivers without intermediate basin statistics. Therefore, to achieve the determination of slopes and cross-sections in all sections of the river, the Muskingum hydrological model is a useful method that helps to save information on the depth and flow of the flood at any time by saving time and money. To specify. In this study, the nonlinear parameters of the new Muskingum model are optimized based on the fly Algorithm (MA). In this non-linear model of Muskingum, which has eight parameters, the recovery coefficient γ is used, which has more or less values ​​than the number of peaks discharged in the output hydrograph.To evaluate the performance of Muskingum's new nonlinear model with the new MA Algorithm, the Wilson and Weisman-Lewis case study has been used by many previous researchers for validation.The results of the MA Algorithm for Wilson and Weissman-Lewis rivers show the minimization of the residual squares (SSQ) as the objective function, which is 3.21 for the Wilson River and 68722 for the Weissman River. The results of this study showed that the proposed model has high accuracy in estimating the output discharge values.

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Issue Info: 
  • Year: 

    2020
  • Volume: 

    12
  • Issue: 

    2
  • Pages: 

    351-364
Measures: 
  • Citations: 

    0
  • Views: 

    638
  • Downloads: 

    0
Abstract: 

Today, due to the importance of sustainable groundwater management, groundwater level modeling and forecasting are used to assess and evaluate water resources. The purpose of this study is to evaluate the performance of two models of Extreme Learning Machines (ELM) and Artificial Neural Network (ANN) and the combination of two models with wavelet transmission Algorithms (W-ELM and W-ANN), which ultimately to increases the predictive power and optimization of input weights (the weights between the input and hidden layers) of models, Quantum Particle Swarm Optimization Algorithm (QPSO) has been used. Also, in this study, the data of Ground Water Level of observation wells (GWL), precipitation (P) and average temperature (T) of Urmia Plain aquifer with a time series of 36 years (1981 – 2017) which were collected on monthly scale, are used. Also, in order to evaluate the performance of models, correlation coefficient (R), Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) were used. In this regard, 80% of the data (September 1981 to August 2010) are used for training section and 20% of data (September 2010 to August 2017) used for the test section of models. Based on the results of this study, the hybrid model of W-ELM-QPSO with correlation coefficient (R) 0. 991, 0. 983 and 0. 975, respectively for periods of one, two and three months in the test section, have a better performance than other models and also in addition to predicting power, this model has a high speed in terms of training and testing speed than other models.

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Journal: 

JOURNAL OF RADAR

Issue Info: 
  • Year: 

    2019
  • Volume: 

    7
  • Issue: 

    1 (SERIAL No. 21)
  • Pages: 

    39-51
Measures: 
  • Citations: 

    0
  • Views: 

    494
  • Downloads: 

    0
Abstract: 

In this article an accurate and efficient procedure to design microwave waveguide filters is presented which is based on the S-parameters method combined with optimization Algorithms. The proposed method is fast, since only the full-wave characteristics of a small part of the filter (one building block) are required to design the whole filter. Three different optimization Algorithms; genetic Algorithm (GA), particle swarm optimization Algorithm (PSO) and quantum particle swarm optimization Algorithm (QPSO) are used for tuning the filter response and their performances in filter design are compared. This approach is verified through full-wave simulation using commercial software for post filter, iris filter, and E-plane metal insert filter at Ku, X and W frequency bands, respectively.

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Issue Info: 
  • Year: 

    2014
  • Volume: 

    17
Measures: 
  • Views: 

    135
  • Downloads: 

    106
Abstract: 

BACKGROUND: IN ORDER TO DEVELOP A QSAR MODEL, MOLECULAR DESCRIPTORS ARE USED AS INDEPENDENT VARIABLES. NOWADAYS, THOUSANDS OF DESCRIPTORS CAN BE CALCULATED BY MEANS OF DEDICATED SOFTWARE. HOWEVER, WHEN MODELING A PARTICULAR PROPERTY, IT IS REASONABLE TO ASSUME THAT ONLY A SMALL NUMBER OF DESCRIPTORS ARE SUITABLE FOR BUILDING THE MATHEMATICAL MODEL OF INTEREST. AS A CONSEQUENCE, A KEY STEP IS THE SELECTION OF THE OPTIMAL SUBSET OF MOLECULAR DESCRIPTORS FOR THE DEVELOPMENT OF THE MODEL. THIS IS PRECISELY THE AIM OF THE SO-CALLED FEATURE SELECTION METHODS. FEATURE SELECTION METHODS ARE MORE SIGNIFICANT WHEN THE NUMBER OF FEATURES IS ABUNDANT. AMONG THE FEATURE SELECTION METHODS, STOCHASTIC SEARCH AlgorithmS THAT USE BINARY VERSION OF HEURISTIC SEARCH AlgorithmS ARE MORE NOTABLE BECAUSE THEY FIND THE NEAR OPTIMUM SOLUTION IN A REASONABLE TIME. SO FAR, MANY AlgorithmS HAVE BEEN PROPOSED TO OVERCOME FEATURE SELECTION PROBLEM, BUT NONE OF THEM BEHAVE GENERALLY. THEREFORE, PRESENTATION OF NEW FEATURE SELECTION AlgorithmS IS STILL IMPORTANT. ACCORDINGLY, TWO NEW FEATURE SELECTION AlgorithmS NAMELY BINARY GRAVITATIONAL SEARCH Algorithm (BGSA) AND QUANTUM-BEHAVED PARTICLE SWARM OPTIMIZATION (QPSO) WERE DEVELOPED, CODED AND APPLIED FOR USING IN QSAR STUDIES.METHOD: BGSA IS INTRODUCED BASED ON THE METAPHOR OF GRAVITY AND MOTION LAWS [1]. IN THIS Algorithm, THE SEARCHER AGENTS ARE A COLLECTION OF MASSES WHICH CAN DETERMINE THE POSITION AND STATUS OF THE OTHER MASSES VIA GRAVITATIONAL FORCE. THE POSITION OF EACH MASS IS A SOLUTION OF THE PROBLEM. ACCORDING TO THE FITNESS OF EACH AGENT IN BAYESIAN REGULARIZED ARTIFICIAL NEURAL NETWORK (BRANN), A MASS IS ATTRIBUTED. THE MASSES CHANGE THEIR POSITION BASED ON FORCES EXERTED FROM OTHER MASSES. AFTER OPTIMIZING THE Algorithm PARAMETERS, SEARCHER AGENTS ARE AGGREGATED IN GLOBAL OPTIMUM AND Algorithm IS CONVERGED. THE BGSA WAS APPLIED AS FEATURE SELECTION Algorithm FOR INVESTIGATING THE QUANTITATIVE RELATIONSHIP BETWEEN STRUCTURES OF IMIDAZO [4, 5- B] PYRIDINE DERIVATIVES AND THEIR ANTI-CANCER ACTIVITY. QPSO Algorithm [2] CONSIDERS THE SEARCH SPACE AS A SYSTEM WITH QUANTUM PARTICLES BY INSPIRATION OF HEISENBERG‟S UNCERTAINTY PRINCIPLE AND THEN SCANS IT. IN FACT, THIS Algorithm IS PROBABILITY-BASED VERSION OF PSO Algorithm IN WHICH PARTICLES MOVES IN QUANTUM MANNER INSTEAD OF NEWTONIAN MODE. A POTENTIAL WELL ATTRACTS THE PARTICLES RELATIVE TO THEIR FITNESSES. THE FITNESS OF PARTICLES IS DETERMINED BY BRANN. THE PARTICLES TRANSFER TO THEIR NEW POSITIONS AFTER EXCHANGING THEIR INFORMATION WITH EACH OTHER. THIS METHOD WAS SUCCESSFULLY APPLIED FOR ANTI-HIV ACTIVITY MODELING OF FLAVONOID DERIVATIVES.

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Issue Info: 
  • Year: 

    2024
  • Volume: 

    13
  • Issue: 

    25
  • Pages: 

    33-49
Measures: 
  • Citations: 

    0
  • Views: 

    16
  • Downloads: 

    0
Abstract: 

This article investigates the problem of simultaneous attitude and vibration control of a flexible spacecraft to perform high precision attitude maneuvers and reduce vibrations caused by the flexible panel excitations in the presence of external disturbances, system uncertainties, and actuator faults. Adaptive integral sliding mode control is used in conjunction with an attitude actuator fault iterative learning observer (based on sliding mode) to develop an active fault tolerant Algorithm considering rigid-flexible body dynamic interactions. The discontinuous structure of fault-tolerant control led to discontinuous commands in the control signal, resulting in chattering. This issue was resolved by introducing an adaptive rule for the sliding surface. Furthermore, the utilization of the sign function in the iterative learning observer for estimating actuator faults has not only enhanced its robustness to external disturbances through a straightforward design, but has also led to a decrease in computing workload. The strain rate feedback control Algorithm has been employed with the use of piezoelectric sensor/actuator patches to minimize residual vibrations caused by rigid-flexible body dynamic interactions and the effect of attitude actuator faults. Lyapunov's law ensures finite-time overall system stability even with fully coupled rigid-flexible nonlinear dynamics. Numerical simulations demonstrate the performance and advantages of the proposed system compared to other conventional approaches.

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