مطالب

Due to the extensive use of communication networks and the ease of communicating via wireless networks, these types of networks are increasingly considered. Usability in any environment without the need for monitoring and environmental engineering of these networks has been caused increasing use of it in various fields. It also caused the emergence of security problems in the sending and receiving information that intrusion detection has been raised as the most important issue. Hence, Network intrusion detection system (NIDS) is the process of identifying malicious activity in a network by analyzing the network traffic behavior. A wireless sensor network is composed of sensors that are responsible for collecting information from the environment. These wireless networks, because of the limitation of resources, mobility, and critical tasks, are relatively high vulnerabilities in comparison to other networks. Therefore, forecasting and intrusion detection systems play an important role in providing security in wireless sensor networks that can involve a wide range of attacks. Traffic behavior in the network has many features and dimensions, so dimensionality reduction plays a vital role in IDS, since detecting anomalies from high-dimensional network traffic features is a time-consuming process. Feature selection influences the speed of the analysis and detection. For this purpose, in the current study, a new approach is proposed to predict the intrusion of wireless networks using firefly based feature selection and fast learning network. Selected features in the feature selection phase are used as inputs to the fast learning network to analyze the intrusion of the network in real-time. According to the simulation results, it can be said that the fast neural network method continues training so as to avoid overfitting error. While neural networks further learn training set features until the training process is completed. Thus, the occurrence of overfitting phenomenon in neural networks is common. Therefore, the proposed method grants better performance than the neural network method in predicting new attacks on the network.

With the emergence of the World Wide Web, Electronic Commerce (E-commerce) has been growing rapidly in the past two decades. Intelligent agents play the main role in making the negotiation between different entities automatically.  Automated negotiation allows resolving opponent agents' mutual concerns to reach an agreement without the risk of losing individual profits. However, due to the unknown information about the opponent's strategies, automated negotiation is difficult. The main challenge is how to reveal the optimal information about the opponent's strategy during the negotiation process to propose the best counter-offer. In this paper, we design a buyer agent which can automatically negotiate with the opponent using artificial intelligence techniques and machine learning methods. The proposed buyer agent is designed to learn the opponent's strategies during the negotiation process using four methods: "Bayesian Learning", "Kernel Density Estimation", "Multilayer Perceptron Neural Network", and "Nonlinear Regression". Experimental results show that the use of machine learning methods increases the negotiation efficiency, which is measured and evaluated by parameters such as the rate agreement (RA), average buyer utility (ABU), average seller utility (ASU), average rounds (AR). Rate agreement and average buyer utility have increased from 58% to 74% and 90% to 94%, respectively, and average rounds have decreased from 10% to 0.04%.