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        1 - A Multi-objective Multi-agent Optimization Algorithm for the Community Detection Problem
        Amirhossein Hosseinian Vahid Baradaran
        This paper addresses the community detection problem as one of the significant problems in the field of social network analysis. The goal of the community detection problem is to find sub-graphs of a network where they have high density of within-group connections, whil More
        This paper addresses the community detection problem as one of the significant problems in the field of social network analysis. The goal of the community detection problem is to find sub-graphs of a network where they have high density of within-group connections, while they have a lower density of between-group connections. Due to high practical usage of community detection in scientific fields, many researchers developed different algorithms to meet various scientific requirements. However, single-objective optimization algorithms may fail to detect high quality communities of complex networks. In this paper, a novel multi-objective Multi-agent Optimization Algorithm, named the MAOA is proposed to detect communities of complex networks. The MAOA aims to optimize modularity and community score as objective functions, simultaneously. In the proposed algorithm, each feasible solution is considered as an agent and the MAOA organizes agents in multiple groups. The MAOA uses new search operators based on social, autonomous and self-learning behaviors of agents. Moreover, the MAOA uses the weighted sum method (WSM) in finding the global best agent and leader agent of each group. The Pareto solutions obtained by the MAOA is evaluated in terms of several performance measures. The results of the proposed method are compared with the outputs of three meta-heuristics. Experiments results based on five real-world networks show that the MAOA is more efficient in finding better communities than other methods. Manuscript profile
      • Open Access Article

        2 - A Goal-Based Approach for the Holonification of Holonic Multi-Agent Systems
        Ahmad Esmaeili N. Mozayani M. R. Jahed Motlagh
        Holonic structures are a hierarchical formation of holons that are developed and used for the purpose of restricting interaction domains, reducing uncertainty, or forming the high level goals of multi-agent systems, in such a way that the system benefits a high degree o More
        Holonic structures are a hierarchical formation of holons that are developed and used for the purpose of restricting interaction domains, reducing uncertainty, or forming the high level goals of multi-agent systems, in such a way that the system benefits a high degree of flexibility and dynamism in response to environmental changes. Although the holonic multi-agent systems are extensively used in modeling and solving complex problems, most of its prerequisites, like forming the body holons and dynamically controlling its structure, use very simple application-specific models. This is due to the immaturity of the research literatures in this field. In this article, an endeavor is made to propose a goal-based approach for the formation of holonic structures, using the concepts in social science and organizational theory. The use of concepts like role, skill, and goal structures, makes the proposed method possible to be used in wide range of applications. In order to demonstrate the capabilities of the method and also the way it can be applied in real world problems, a test bed based on the application of wireless sensor networks in object tracking is designed and presented. In this application, the sensors, which are distributed in the environment as simple agents, using holonic structures, are responsible for the track of any alien objects that enter and move in the environment. According to the empirical results of the simulations, the proposed holonic approach has provided successful performance in terms of tracking quality and energy consumption of the sensors. Manuscript profile
      • Open Access Article

        3 - Fixed-Time Consensus of Fractional-Order Single Integrator Multi-Agent Systems
        Hossein Zamani وحيد جوهري مجد Khosro Khandani
        The problem of consensus in fractional order single-integrator multi-agent systems has been studied in this paper. The effect of memory is considered using the Riemann-Liouville fractional derivative in the dynamics of the agents. In order to achieve convergence among t More
        The problem of consensus in fractional order single-integrator multi-agent systems has been studied in this paper. The effect of memory is considered using the Riemann-Liouville fractional derivative in the dynamics of the agents. In order to achieve convergence among the agents, a fractional order control protocol based on the error signal between neighboring agents is proposed. Using Lyapunov's stability theorem, a Lyapunov function is introduced that shows that the agents converge over a specified settling time and the upper bound of the settling time is obtained. The merit of the proposed bound for the settling time is that it is independent of the initial conditions. Finally, some simulations are provided to confirm the introduced method. Manuscript profile
      • Open Access Article

        4 - Design of a Secondary Controller Based on Distributed Cooperative Control of Distributed Generators (DGs) with Multi-Agent Systems Approach Considering DoS Cyber Attacks
        Abdollah Mirzabeigi Ali Kazemy Mehdi Ramezani Seyed Mohammad Azimi
        Today, in many control methods, neighboring system information is used for better control and synchronization between different units, and therefore, in the access and transmission of information through communication links, problems such as disruption, uncertainty, noi More
        Today, in many control methods, neighboring system information is used for better control and synchronization between different units, and therefore, in the access and transmission of information through communication links, problems such as disruption, uncertainty, noise, delay, and cyber-attacks occur. In this paper, the effect of the Denial of Service (DoS) cyber-attack on the microgrid in island mode is investigated and a cooperative distributed hierarchical controller is designed with the presence of this cyber-attack. Distributed Generations (DGs) have been analyzed with the help of multi-agent systems and the communication network between them using graph theory. The effects of the DoS cyber-attack on the model of DGs are mathematically formulated and in proving the stability and synchronization of frequency and voltage, the suitable Lyapunov function is presented and the stability analysis of DGs against these cyber-attacks is performed and the stability and synchronization conditions of DGs are proved. To confirm the proposed theoretical issues, a case study model is simulated despite the DoS attack on the communicative links in Matlab Simulink, and the results show the performance of the designed controller in different conditions. Manuscript profile
      • Open Access Article

        5 - Stabilizing and Synchronizing the Islanded Microgrid with the Presence of Sensor and Actuator Fault and Cyber-Attack with Secondary Controller Design
        Abdollah Mirzabeigi Ali Kazemy Mehdi Ramezani Seyed Mohammad  Azimi
        In many microgrid control methods, the output information of sensors and actuators of neighbouring distributed generators (DGs) is used to stabilize and synchronize voltage and frequency. Many problems such as disturbances, uncertainty, unmodeled dynamics, cyber-attacks More
        In many microgrid control methods, the output information of sensors and actuators of neighbouring distributed generators (DGs) is used to stabilize and synchronize voltage and frequency. Many problems such as disturbances, uncertainty, unmodeled dynamics, cyber-attacks, noise, time delay, and measurement errors cause invalid data problems and errors in the system. Better microgrid control depends on the quality of data measured or sent from the output of sensors and actuators. In this paper, according to the advantages of the Cooperative distributed hierarchical control, it is used for control and synchronization in the islanded microgrid with the presence of sensor and actuator error. To synchronize DGs with multi-agent systems and communication channels, it is modeled with graph theory. To stabilize and synchronize, sensor and actuator error in the DG model is mathematically formulated. In the proof of stability and synchronization, the appropriate Lyapunov candidate is presented and the conditions of stability and synchronization are proved. Finally, to show the effectiveness of the designed controller in solving communication channel problems and verifying the presented theory, a case study is simulated in the MATLAB/Simulink software environment with the presence of error and cyber-attack of sensors and actuators. Manuscript profile
      • Open Access Article

        6 - Analysis of the Effects of Different Cyber Attacks on the Secondary Controller in Island Microgrids
        Abdollah Mirzabeigi ali kalantarnia
        With the advancement of science, in many control methods, the neighbor system is used to better control and synchronize between different information of microgrids. There are problems in accessing and transmitting information through communication links. In this article More
        With the advancement of science, in many control methods, the neighbor system is used to better control and synchronize between different information of microgrids. There are problems in accessing and transmitting information through communication links. In this article, vulnerability and acceptance of secondary control methods are distributed. Also, denial-of-service (DoS) cyber-attacks, sensors and actuators, and hijacking on the island microgrid have been investigated. In addition to stability, synchronization is also analyzed in this article. Multi-agent systems have been used for synchronization. Cyber-attacks are mathematically formulated in the controller. A suitable controller is designed to eliminate the attacks. In the stability and synchronization of frequency and voltage, the Lyapunov function is presented and simultaneous analysis of stability and synchronization has been done with practical proofs. The resilience factor has been calculated for different attacks. It is shown that the system is resilient against cyber-attacks. A case study has been simulated in MATLAB/Simulink to approve the theoretical issues. Manuscript profile