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تخمين تعداد سيگنالهاي طيف گسترده پرش فركانسي وارده به يك آنتن يكي از مسايل مورد توجه است. روش هاي تجزيه مقادير ويژه مورد استفاده براي تخمين تعداد كاربران براي SNR هاي پايين از كارايي لازم برخوردار نيست. روش كار به اين صورت است كه ابتدا با استفاده از تحليل آنتروپي يك زير مجموعه ديتاي بدون پرش از سيگنال جدا شده و سپس با استفاده از تجزيه مقادير ويژه تعداد كاربران بدست ميآيد. در اين مقاله سعي شده است تا مشكل تخمين تعداد كاربران در SNR هاي پايين با اعمال يك بلوك حذف نويز به آنتروپي بدست آمده از سيگنال ورودي بهبود بخشيده شود.

برنامه نويسي ژنتيك، از جمله الگوريتم هاي تكاملي است كه توانايي زيادي، نسبت به اغلب روش هاي يادگيري ماشين دارا م ي باشد . مشكل اين روش، زمانبر بودن اجراي آن است . در اين مقاله، هدف استفاده از برنامه نويسي ژنتيك و تطبيق آن به منظور تصديق هويت گوينده و بررسي هويت كاربران از طريق صداي آنهاست . ايده هاي متعددي را پيشنهاد نموده ايم تا به كمك آنها بتوانيم ضمن افزايش كارايي روش برنام ه نويسي ژنتيك براي تصديق هويت گويند ه، سرعت آموزش مدلهاي گويندگان را كه معمولا در روش برنام ه نويسي ژنتيك بسيار زمانبر است را افزايش دهيم. براي اين منظور سعي شده است تا با روشهايي چون خوشه بندي به كمك روشهاي چندي سازي برداري و نيز با استفاده از توابع گوسي بدست آمده از روش مدل مخلوط گوسي GMM به جاي بردارهاي ويژگي داده هاي آموزشي ، حجم داده هاي آموزشي را كاهش دهيم و بدين ترتيب بر سرعت ساخت مدلهاي حاصل از برنامه نويسي ژنتيك بيافزائيم. نتايج بدست آمده نشان مي دهند كه استفاده از ميانگين هاي مدل هاي مخلوط گوسي حاصل از داده هاي آموزشي گوينده خودي و گويندگان غيرخودي به جاي استفاده مستقيم از داده هاي آموزشي و بطور مشابه استفاده از ميانگين هاي مدل مخلوط گوسي حاصل از داده هاي آزمايشي، منجر به دقت خوبي در تصديق هويت گويندگان و نيز افزايش سرعتي در حد 20 برابر (از 5 ساعت به 15 دقيقه) در آموزش مدلهاي گويندگان به كمك روش برنامه نويسي ژنتيك مي گردد.

In wireless sensor network often micro-battery with very limited power provides the energy of sensor nodes. Since sensors are usually utilized in remote or hostile environments, recharging or replacing the battery of the sensors is something quite undesirable or even impossible. Thus long system lifetime is a must. Sleep scheduling is a mechanism in wireless sensor network to save energy. In this paper, we propose an energyefficient distributed scheduling method considering mobile target tracking also called dynamic target coverage. The algorithm is based on cellular learning automata. In this algorithm, each node is equipped with a learning automaton which will learn (schedule) the proper on and off times of that node based on the movement nature of a single moving target. To evaluate the proposed method it is tested under straight with constant velocity movement model of target. The results of experimentations have shown that the proposed scheduling algorithm outperforms two existing dynamic target coverage scheduling methods.

Grid environment is being a service oriented infrastructure in which many heterogeneous resources participate for providing the high performance computation. On of bug issue in the grid environment is the vagueness and uncertainty between advertised resources and requested resources. In this work we propose a solution for the vagueness and uncertainty problems based on rough set theory. Here you can see how the rough set theory is developed to deal with the problem. We also report the result of the solution obtained from the simulation in Gridsim simulator. The comparison has been made between the proposed method and UDDI and OWL-S combined method. Rough set theory shows much better precision for the cases with vagueness and uncertainty.

Asynchronous protocols exhibit various noise robustness and when used in GALS NoC links, they can directly affect the signal integrity. In this paper we study the noise robustness of two well-known asynchronous protocols, namely Dual-Rail (DRP) and Bundled-Data (BDP) in the GALS NoC links, and subsequently confirm our claims through simulations. We apply an enhanced version of BDP and DRP to 32/64 parallel line links, show results in terms of noise robustness using global interconnect features, specified in the ITRS roadmap for 32nm technology. The simulation results for two thousand random generated inputs show that the number and the amplitude of noise glitches over ‘0’ state lines as well as the required threshold voltage needed for avoiding errors in BDP link are much lower than in DRP's. Therefore, BDP links can present better signal integrity features and have less overhead compared to DRP's, employing only some simple noise reduction techniques and more timing adjustment effort.

Discriminative subspace analysis is a popular approach for a variety of applications. There is a growing interest in subspace learning techniques for face recognition. Principal component analysis (PCA) and eigenfaces are two important subspace analysis methods have been widely applied in a variety of areas. However, the excessive dimension of data space often causes the curse of dimensionality dilemma, expensive computational cost, and sometimes the singularity problem. In this paper, a new supervised discriminative subspace analysis is presented by encoding face image as a high order general tensor. As face space can be considered as a nonlinear submanifold embedded in the tensor space, a decomposition method called Tucker tensor is used which can effectively decomposes this sparse space. The performance of the proposed method is compared with that of eigenface, Fisherface, tensor LPP, and ORO4×2 on ORL and Weizermann databases. Conducted experimental results show the superiority of the proposed method.

Being able to predict the coming seizure can impressively improve the quality of the patients' lives since they can be warned to avoid doing risky activities via a prediction system. Here, a locally linear neuro fuzzy model is used to predict the EEG time series. Subsequently, this model is utilized in accompany with Singular Spectrum Analysis for prediction. Afterward, an information theoretic criterion is used to select a reliable subset of input variables which contain more information about the target signal. Comparison of three mentioned methods on one hand shows that SSA enables our prediction model to extract the main patterns of the EEG signal and highly improves the prediction accuracy. On the other hand, applying the method of channel selection to the model yields more accurate prediction. It is shown that fusion of some certain signals provides more information about the target and considerably improves the prediction ability.

In this paper, we present a new measure for evaluating similarity changes in a multi agent system. The similarity measure of the agents changes during the learning process. The similarity differences are because of any composition or decomposition of some agent sets. The presented measure, defines the changes of homogeneity of agents by composition and decomposition. The utility of the metrics is demonstrated in the experimental evaluation of multi agent foraging. The results show that while the similarity difference gets a positive value, the performance grow rapidly.

In this paper, a new fuzzy fading memory (FFM) is developed in order to aid a modified input estimation (MIE) technique and enhance its performance in tracking high maneuvering targets. The MIE has been introduced recently and performs well in tracking low and medium maneuvering targets. However, due to some modeling errors, the accuracy of this tracker may be seriously degraded in presence of high maneuvers. To cope with this difficulty, an intelligent approach based on FFM is presented in this paper. Simulation results prove the efficiency of the proposed method in tracking high maneuvering targets.

With ever increasing complexity of software systems, it is now more evident than ever that a fundamental change in software engineering practices is required. In this paper we discuss the nature of change and its implications. The notion of passive autonomy is introduced as a reference to the relative autonomy of business entities, and we claim that realizing the passive autonomy in information systems would results in systems far more adaptable and aligned with business’ needs. In order to realize this autonomy, theuse of autonomous agents as representing real world autonomous entities is suggested. After pointing out the shortcomings of current agent based architectures, a new architecture is proposed, based on indirect, multilateral negotiation. The suitability of this architecture is demonstrated in a simple case of beer game and it is shown that the bullwhip effect is remedied to some extent using this new architectural approach.