This paper revisits the Arimoto-algorithm in the discrete-time case. It is shown that if a plant satisfies a positivity condition, there always exists a learning gain so that the algorithm converges monotonically to z...
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The rapid growth of image archives increases the need for efficient and fast tools that can retrieve and search through large amount of visual data. In this paper we propose an efficient method of extracting the image...
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The rapid growth of image archives increases the need for efficient and fast tools that can retrieve and search through large amount of visual data. In this paper we propose an efficient method of extracting the image color content, which can serve as an image digital signature, allowing the efficient indexing and retrieval of large Internet-based multimedia databases. We applied the proposed method using the images from two Internet databases containing a collection of images of fine arts and a database of low resolution images, and show that the new method of image color representation is robust to image distorsions caused by resizing and compression and can be incorporated into existing web-based retrieval systems, that exploit the information on color content of digital images.
A new field weakening control of a linear torque controlled interior permanent magnet synchronous motor (IPMSM) drive is proposed in this paper. The theoretical basis of the proposed field weakening control is first p...
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A new field weakening control of a linear torque controlled interior permanent magnet synchronous motor (IPMSM) drive is proposed in this paper. The theoretical basis of the proposed field weakening control is first proposed and the corresponding analytical forms are also derived. The whole operational regions of an IPMSM are divided into three regions according to the motor speed. They are the constant torque limit region (Region I), the partial field weakening region (Region II), and the full field weakening region (Region III). However, only two control modes, namely the constant torque limit control mode and the field weakening control mode, are required. A region detector is proposed to choose the correct control mode efficiently according to the motor speed and the demanded torque. In addition, to fully use the maximum torque capability in the field weakening region, a variable line current magnitude limiter is also proposed to simplify the complexity of the control algorithm. Finally, the proposed control is implemented fully digitally by using a fixed point DSP TMS320F240 to simplify the hardware circuits and some experimental results are given to verify the effectiveness of the proposed linear torque control strategy over the field weakening region.
In this paper, hybrid impulsive and switching control of nonlinear systems and its application to chaotic systems are considered. Using switched Lyapunov functions, some new general criteria for exponential stability ...
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This paper studies the problem of asymptotic stability for a class of high-order dynamic neural networks with time delays. Several useful lemmas are proved in this paper first. After that, the sufficient conditions fo...
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This paper studies the problem of asymptotic stability for a class of high-order dynamic neural networks with time delays. Several useful lemmas are proved in this paper first. After that, the sufficient conditions for the asymptotic stability of the system with constant time delays are introduced, and also this asymptotic stability problem for the system with time-varying delays is put forward. In order to obtain above results, the Lyapunov-Krasovskii stability theory for functional differential equations and the linear matrix inequality (LMI) approach are employed to investigate this kind of problems. Finally, some numerical examples are given to illustrate the advantages of our approach
This article deals with a robust control practical application designed and run on different kinds of embedded PCs. As a control object Ball and Beam experiment was chosen. The system was simulated on the mathematical...
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This article deals with a robust control practical application designed and run on different kinds of embedded PCs. As a control object Ball and Beam experiment was chosen. The system was simulated on the mathematical model in Matlab and was subsequently applied to the real model of Ball and Beam. For measure and control in real-time there was used IO card from Advantech, embedded PC and operating system Linux. One part of that solution is a visualization of the process mentioned above, too.
This paper presents a framework design solution for parallel computing digital systems design. The framework uses the Simulink software as a standard design entry tool. The key role in the Framework design plays the n...
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This paper presents a framework design solution for parallel computing digital systems design. The framework uses the Simulink software as a standard design entry tool. The key role in the Framework design plays the netlist compiler, which is a stand-alone programm, created in C++. The framework assumes to be used for creating the parallel systems with distributed memory and can be targetted to powerful FPGA devices. So the computing systems designed in the Framework are naturally synchronnous and the language finally used for describing the system is the VHDL. The Simulink software together with a designed netlist compiler constitutes an Integrated Development Environment (IDE).
Document clustering is one of the popular techniques that assist users in organizing collections of documents. Two successful models of unsupervised neural networks, self-organizing map (SOM) and adaptive resonance th...
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Document clustering is one of the popular techniques that assist users in organizing collections of documents. Two successful models of unsupervised neural networks, self-organizing map (SOM) and adaptive resonance theory (ART), have shown promising results in this task. Most of the existing neural network based document clustering techniques rely on a "bag of words" document representation. Each word in the document is considered as a separate feature, ignoring the word order. We investigate the use of phrases rather than words as document features applied to our proposed document clustering technique, called hierarchical SOMART (HSOMART), which is a hierarchical network built up from independent SOM and ART neural networks. We describe a phrase grammar extraction technique, and the proposed HSOMART. The experimental results of clustering documents from the REUTERS corpus using the extracted phrases as features show an improvement in the clustering performance evaluated using the entropy and F-measure.
The rapid growth of image archives increases the need for efficient and fast tools that can retrieve and search through large amount of visual data. In this paper we propose an efficient method of extracting the image...
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