انجمن کامپیوتر ایران

متناسب با کاربرده اي مختلف ، پروتکلهاي گوناگوني بر اي کنترل دسترسي به کانال در شبکهه اي حسگر ز يرآب ي طراح ي شده است. ولي تا بحال ي ک پروتکل خوشه اي مناسب بر اي کاربرده اي مانيتورينگ بلادرنگ توسعه نيافته است. يکي از معمار ي پروتکل ه اي کارا براي کاربردهاي مذکور در شبکههاي خشکي LEACH است . در اين مقاله خواهيم ديد که به کار بردن پروتکل LEACH اصلي در زير آب به دليل مشکلات محيطي اعم از تأخير انتشار و واريانس اين تأخير، متداول بودن خرابي گرهها و خطاي بيت بالا در ارتباطات صو تي عملاً شبکه را از فعاليت بازميدارد. ولي ميتوان با اعمال تغ ييرات ي شامل گستردهتر کردن مراحل فاز پيکربندي و ارسال بستة کنترل ي از سو ي سرخوشه براي گرههاي سالم، کارايي اين پروتکل را از منظر بهره وري استفاده از پهناي باند تا ۶۰ % بازي ابي کرد و پيوست گي اطلاعات را در بيشتر از % ۹۹ زمان تضمين کرد.

Abstract—In this paper we discussed about utilizing methods and techniques of semantic web in the Intrusion Detection Systems. To extract semantic relations between computer attacks and intrusions in a Distributed Intrusion Detection System, we use ontology. Protégé software is our selected software for building ontology. In addition, we utilized Jena framework to make interaction between MasterAgent and attacks ontology. Our Distributed Intrusion Detection System is a network which contains some IDSagents and a special MasterAgent. MasterAgent contains our proposed attacks ontology. Every time a IDSagent detects an attack or new suspected condition, it sends detection’s report for MasterAgent. Therefore, it can extract the semantic relationship among computer attacks and suspected situations in the network with proposed ontology. Finally, the experience shows that the pruposed system reduced the rate of false positive and false negative.

Wireless sensor networks are limited in energy. Any routing protocol used in wireless sensor networks should take into consideration the time sensitive nature of the traffic in such networks, along with the amount of energy left for each sensor. In this paper we present an energy aware packet delivery mechanism for probabilistic Quality of Service (QoS) guarantee in wireless sensor networks. Each node takes routing decisions based on geographic progress towards the destination sink, required end-to-end total reaching probability, delay at the candidate forwarding node and residual energy. The simulation results demonstrate that the proposed protocol effectively improves the energy usage efficiency of the sensor nodes, maximizing the lifetime of the entire sensor network, while keeping guaranteed QoS.

A user of Brain Computer Interface (BCI) system must be able to control external computer devices with brain activity. Although the proof-of-concept was given decades ago, the reliable translation of user intent into device control commands is still a major challenge. There are problems associated with classification of different BCI tasks. In this paper we propose the use of chaotic indices of the BCI. We use largest Lyapunov exponent, mutual information, correlation dimension and minimum embedding dimension as the features for the classification of EEG signals which have been released by BCI Competition IV. A multi-layer Perceptron classifier and a KMSVM( support vector machine classifier based on kmeans clustering) is used for classification process, which lead us to an accuracy of 95.5%, for discrimination between two motor imagery tasks.

In this paper we propose a new integration method for multi-feature object tracking in a particle filter framework. We divide particles into separate clusters. All particles within a cluster measure a specific feature. The number of particles within a cluster is in proportion to the reliability of associated feature. We do a compensation stage which neutralizes the effect of particles weights mean within a cluster. Compensation stage balances the concentration of particles around local maximal. So, particles are distributed more effectively in the scene. Proposed method provides both effective hypothesis generation and effective evaluation of hypothesis. Experimental results over a set of real-world sequences demonstrate better performance of our method compared to the common methods of feature integration.

This paper introduces a revisited hybrid algorithm for function approximation. In this paper, a simple and fast learning algorithm is proposed, which automates structure and parameter identification simultaneously based on input-target samples. First, without need of clustering, the initial structure of the network with the specified number of rules is established, and then a training process based on the error of other training samples is applied to obtain a more precision model. After the network structure is identified, an optimization learning, based on the criteria error, is performed to optimize the obtained parameter set of the premise parts and the consequent parts. At the end, comprehensive comparisons are made with other approaches to demonstrate that the proposed algorithm is superior in term of compact structure, convergence speed, memory usage and learning efficiency.

This paper estimates and segments the moving objects based on center of mass model to decrease the search window and to provide a new algorithm, which achieves an accurate and rapid tracking. Furthermore, a novel method is proposed to update the template size adaptively by using estimation and segmentation of moving objects. The estimated results of moving target is transformed to wavelet domain and target tracking is performed in that domain. To improve the algorithm center of mass model is performed in wavelet domain. By using kalman predictor and thresholding method, a new approach is presented for object tracking failure and recovery.

Human can determine optimal behaviors which depend on the ability to make planned and adaptive decisions. In this paper, we have proposed a predictive structure based on neuropsychological evidences to model human decision making process by concentrating on the role of frontal brain regions which are responsible for predictive control of human behavior. We have considered a model-based reinforcement learning framework to implement the relations between these brain areas. Finally, we have designed an experimental test to compare the function of model with human behavior in a maze task. Our results reveal that there is more than reward and punishment in human behavior, and considering higher cognitive functions such as prediction will help to have more reliable models which could better describe human behavior.