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      • Open Access Article

        1 - Classification of Brain Tumor Grades by MRI Images using Artificial Neural Network
        Melika Aboutalebi Rezvan Abbasi
        In recent years, the use of MRI images has been very much considered due to their high clarity and high quality in the diagnosis and determination of brain tumor and its features. In this study, to improve the performance of tumor detection, we investigated comparative More
        In recent years, the use of MRI images has been very much considered due to their high clarity and high quality in the diagnosis and determination of brain tumor and its features. In this study, to improve the performance of tumor detection, we investigated comparative approach of the different classifiers to select the most appropriate classifier for identifying and extracting abnormal tissue and selected the best one by comparing their detection accuracies rate. In this research, GLCM and GLRM methods are used to extracting discriminating features. Thus results in they reduce the computational complexity. fuzzy entropy measurement method is used to determine the optimal properties and finally, we compared the four FFNN, MLP, BPNN, ANFIS neural networks to perform the decision making and classification process. The purpose of these four neural networks are to develop tools for discriminating the malignant tumors from benign ones assisting deciding in clinical diagnosis. Based on the results, we achieved high results among all classifiers. The proposed methodology results in accurate and speedy detection of tumor in brain along with identification of precise location of the tumor. In our opinion, the use of these classifiers can be very useful in the diagnosis of brain tumors in MRI images. Our other goal is to prove the suitability of the ANN method as a valuable method for statistical methods. The novelty of the paper lies in the implementation of the proposed method for discriminating the malignant tumors from benign which results in accurate and speedy detection of tumor in brain along with identification of precise location of the tumor. The efficiency of the method is proved through plenty of simulations and comparisons. Manuscript profile
      • Open Access Article

        2 - Optimization of the DFIG Wind Turbine Controller Parameters by the Gray Wolf Algorithm
        Mahyar Abbaszadeh Rezvan Abbasi
        The increase in the power generated by the wind hashad effects on the performance of the power system incases such as power quality, safety, stability, andvoltage control. The wind turbines are used to generateelectrical energy from wind. They can work in fixedor variab More
        The increase in the power generated by the wind hashad effects on the performance of the power system incases such as power quality, safety, stability, andvoltage control. The wind turbines are used to generateelectrical energy from wind. They can work in fixedor variable speeds. The asynchronous generator isdirectly connected to the grid for the fixed-speed windturbines. In order to connect the DFIG (Doubly-FedInduction Generator) to the grid, this machine must beable to integrate its generated power into the grid in aspecific voltage (the grid voltage level). The mainDFIG controlling method is the use of field-orientedvector control for regulating the rotor flux. The DFIGvector control consists of two main parts as grid sideconverter control and rotor side converter control. Therotor side converter is used to control the grid outputpower. This converter regulates the power factors inthe terminals, and actually restores the generatedpower deviation from the reference power through thePID controllers, besides guaranteeing the stability ofthe induction generator. In the current study, the powerwas controlled through the determination of the PIDoptimal coefficient of the rotor and grid sidescontrollers and the gray wolf algorithm in theMATLAB software. In addition, the stability of thesmall signal of the grid equipped with the doubly-fedwind generator in the wind speed turbulenceconditions was optimized to satisfy the requiredcriteria in output active and reactive power of a DFIG.From the simulation results it is observed that theproposed controller yields better results whencompared to other methods in literature in terms ofperformance index. Manuscript profile