Journal of Intelligent & Fuzzy Systems - Volume 16, issue 2

Authors: Chimmanee, Sanon | Wipusitwarakun, Komwut | Runggeratigul, Suwan

Article Type: Research Article

Abstract: Delay-sensitive Internet applications are required for high service quality in IP networks. Unfortunately, the existing load balancing tools are developed to distribute Internet traffic between routes without considering the current status of applications and network resources. This results in a degradation of quality of the applications when these load balancing tools are implemented. Since the characteristics of Internet applications such as traffic patterns are uncertain, and the usage of network resources is time-variant, an …adaptive load-balancing tool is needed to cope with the changes in the current status of the system. In our previous work, we have presented a per-application load balancing for voice over IP based on a neuro-fuzzy integration. The previous concept of load balancing is to classify applications with similar characteristics to the same class and results in achieving the desired targets. This paper intends to extend upon the previous mechanism in order to apply it to other delay-sensitive applications. However, since the previous concept and mechanism are not applicable to general Internet applications, this paper proposes the idea of load balancing to classify applications with different characteristics to be possible in the same class provided that the QoS of the desired application is not degraded. This results in optimizing both the QoS requirement for the general delay-sensitive applications and the utilization of network resources, simultaneously. Show more

Keywords: Intelligence adaptive control, hybrid neuro-fuzzy system, adaptive classification, load balancing, and Quality of Service (QoS)

Citation: Journal of Intelligent & Fuzzy Systems, vol. 16, no. 2, pp. 79-93, 2005

Authors: Kim, Min-Soeng | Kim, Chang-Hyun | Lee, Ju-Jang

Article Type: Research Article

Abstract: In this paper, a new evolutionary algorithm for optimization of fuzzy models is proposed. For simultaneous optimization of structure and parameters of a fuzzy model, unique encoding scheme and appropriate evolutionary operators are proposed. There are three important aspects in fuzzy modeling: modeling accuracy, rule compactness, and interpretability of input membership functions. Thus, a new fitness function is proposed to consider the three objectives simultaneously. Through simulations on two well-known modeling problems, it is …shown that the proposed algorithm is effective in finding an accurate fuzzy model with compact number of fuzzy rules. In addition, the fuzzy model uses well distributed membership functions that helps to increase interpretability of the fuzzy model. Show more

Citation: Journal of Intelligent & Fuzzy Systems, vol. 16, no. 2, pp. 95-105, 2005

Authors: Musilek, Petr | Guanlao, Rhea | Barreiro, Guillermo

Article Type: Research Article

Abstract: Aggregation operations play an important role in decision-making problems where a weighted combination of several criteria is used to select an alternative with the strongest support. In fuzzy set theory, aggregation operations are usually modeled as intersection, union, or as combination of both. The particular form and algebraic properties of these operations vary according to requirements for compensation among the criteria and other characteristics of the given decision-making situation. Traditionally, only algebraically …well-behaved operations have been considered for this purpose. By relaxing some algebraic constraints, more realistic operations can be obtained that closely capture certain features of human decision-making, such as preferences and a limited level of detail. This paper proposes a method to generate fuzzy aggregation operations using genetic programming. It is shown that an evolutionary process, facilitated by genetic programming, has the capacity to generate new valid fuzzy aggregation operations and to reproduce existing ones. By varying process conditions, encoded in a fitness function, it is possible to obtain operations with different logical and algebraic properties. This approach, based solely on the axioms which define the desired class of operations, explores the space of possible functions and often leads to discovery of new operations. However, the proposed system can also be used to generate aggregation operations that fit a collected data set. This application is very important as it provides a powerful new tool for modeling and processing empirical data. Show more

Citation: Journal of Intelligent & Fuzzy Systems, vol. 16, no. 2, pp. 107-118, 2005

Authors: Niknam, T. | Ranjbar, A.M. | Shirani, A.R.

Article Type: Research Article

Abstract: Technology enhancement of Distributed Generations, as well as deregulation and privatization in power system industry, shows a new perspective for power systems and subsystems. When a substantial portion of generation is in the form of dispersed and small units, a new connection pattern emerges whereby the dispersed units are embedded in reticulation infrastructure. Now, the flow of power is no longer the same as in the conventional systems, since the dispersed generating plants contribute with …generation also at the distribution grids level. Connection of generation to distribution grids cannot effectively be made, unless the some especial control and monitoring tools are available and utilizable. State estimation in these kinds of networks, often called mixtribution, is the preliminary and essential tool to fulfill this requirement and also is the subject of this article. Actually, state estimation is an optimization problem including discrete and continuous variables, whose objective function is to minimize the difference between calculated and measured values of variables, i.e. voltage of nodes, and active/reactive powers in the branches. In this paper, a new approach based on Ant Colony Optimization (ACO) is proposed to solve this optimization problem. The feasibility of the proposed approach is demonstrated and compared with methods based on neural networks and genetic algorithms for two test systems. Show more

Keywords: Distributed generation, state estimation, Ant Colony Optimization (ACO)

Citation: Journal of Intelligent & Fuzzy Systems, vol. 16, no. 2, pp. 119-131, 2005

Authors: Ertugrul, Seniz | Hizal, N. Aydin

Article Type: Research Article

Abstract: This paper reports research results on the designing of an intelligent controller by means of modeling human operator actions based on a Man-Machine Interaction Computer Experiment. Different disturbance signals are applied to the single and the double-integration systems under human operator control to collect data for training the Adaptive Network Based Fuzzy Inference-System as the Neuro-Fuzzy controller. The Neuro-Fuzzy system was able to replace the human operator even in the case of a random disturbance signal …applied to the double integrator system. Show more

Citation: Journal of Intelligent & Fuzzy Systems, vol. 16, no. 2, pp. 133-140, 2005

Authors: Zaki, M. | Sobh, Tarek S.

Article Type: Research Article

Abstract: In security environments many complicated and interrelated software elements, such as firewalls, network scanners, event distributors and authentication tools, should work cooperatively. The proposed model consists of Multiagent Intrusion Detection System (MIDS) for gathering attack information. It provides a software environment that can afford a generalization/specialization process in order to accomplish attack abstraction. Such a model is designed to detect attacks of several protocols, such as Port Activity, SMTP, HTTP, and FTP. The system …changes can be obtained by applying an appropriate security auditing policy. As such MIDS includes four agents; 1) Signature Agent (SA), 2) Network Events Agent (NEA), 3) Vulnerability Scan Agent (VSA) and 4) Intrusion Detection Agent (IDA). These agents are running on each host to be monitored. Show more

Keywords: Network security, attacks abstraction, intrusion detection, mobile agent

Citation: Journal of Intelligent & Fuzzy Systems, vol. 16, no. 2, pp. 141-150, 2005

Authors: Kreinovich, Vladik

Article Type: Book Review

Citation: Journal of Intelligent & Fuzzy Systems, vol. 16, no. 2, pp. 151-155, 2005