A heuristic, automatic facial feature extraction approach is presented in this paper. The method is based on the edge density distribution of the image, containing non-occluded, nearly frontal view of one or more face...
详细信息
A heuristic, automatic facial feature extraction approach is presented in this paper. The method is based on the edge density distribution of the image, containing non-occluded, nearly frontal view of one or more faces. In the preprocessing stage, a face is approximated to an ellipse, and genetic algorithm is applied to search for the best ellipse region match. In the feature extraction stage, genetic algorithm is applied to extract the facial features, such as the eyes (with eyebrows), nose and mouth, in the predefined subregions. The simulation results validates that the proposed method is capable of automatically extracting features from various video images effectively under natural lighting environments and in the presence of complex backgrounds, certain amount of artificial noise and of multi-face oriented with angles. This preliminary study advanced from a rich literature provides robust facial feature detection under certain variations in lighting conditions and backgrounds.
In this paper, we propose a genetic algorithm based design procedure for a radial-basis function neural network. A Hierarchical Rank Density Genetic Algorithm (HRDGA) is used to evolve the neural network's topolog...
详细信息
In this paper, we propose a genetic algorithm based design procedure for a radial-basis function neural network. A Hierarchical Rank Density Genetic Algorithm (HRDGA) is used to evolve the neural network's topology and parameters simultaneously. Compared with traditional genetic algorithm based designs for neural networks, the hierarchical approach addresses several deficiencies highlighted in literature. In addition, the rank-density based fitness assignment technique is used to optimize the performance and topology of the evolved neural network to deal with the confliction between the training performance and network complexity. Instead of producing a single optimal solution, HRDGA provides a set of near-optimal neural networks to the designers so that they can have more flexibility for the final decision-making based on certain preferences. In terms of searching for a near-complete set of candidate networks with high performances, the networks designed by the proposed algorithm prove to be competitive, or even superior, to three other traditional radial-basis function networks for predicting Mackey–Glass chaotic time series.
Electroencephalograph (EEG) recordings during right and left motor imagery can be used to move a cursor to a target on a computer screen. Such an EEG-based brain-computer interface (BCI) can provide a new communicatio...
详细信息
This paper addresses the problem of robust filtering for uncertain linear signal models affected by time delays in the state. Uncertainty is structured and the model is assumed to lie in a given bounded polyhedral set...
详细信息
ISBN:
(纸本)0780379241
This paper addresses the problem of robust filtering for uncertain linear signal models affected by time delays in the state. Uncertainty is structured and the model is assumed to lie in a given bounded polyhedral set. The main innovation is the use of a nonrational filter, that is, a filter that also contains delays in the filter state. Robust filtering performance is evaluated using the H2 or the H∞ norm. The performance conditions are delay independent, and provide convex filtering design problems which are convex optimization problems with linear matrix inequalities constraints.
The stability and performance of telepresence systems with kinesthetic (force) feedback operated via a communication network mainly depends on the quality (delay, bandwidth) of communication. The combined position/for...
详细信息
The stability and performance of telepresence systems with kinesthetic (force) feedback operated via a communication network mainly depends on the quality (delay, bandwidth) of communication. The combined position/force control of teleoperation system with time delay using impedance matching filters to achieve robust passivity for the teleoperator/environment and transparency is discussed. The impedance matching filter design is the result of optimization in the frequency domain. An experimental telepresence system using realtime communication network emulation is used to show the validity of the proposed approach.
Shortened product life-cycles decreases the output rate of manufacturing systems as the introduction of new products into the manufacturing system becomes more frequent. Improvements of the development process of manu...
详细信息
Shortened product life-cycles decreases the output rate of manufacturing systems as the introduction of new products into the manufacturing system becomes more frequent. Improvements of the development process of manufacturing systems are needed to increase the output. Information handling and development of control programs based on information reuse are two of the most important improvement areas. These areas, among other things, can be a support for offline verification, which promises to directly increase the output rate due to shortening product introduction times. This paper deals with two problems of the many connected to enabling offline verification. First, a general control program structure, adapted to information reuse, is needed and secondly, the information necessary to generate the control programs needs to be defined. A method is proposed where information from the mechanical design of a cell, from the product, and from manual simulation are reused and automatically converted into control programs that schedule the work in a collision-free, deadlock-free and time-optimized way. The correctness of the generated programs is guaranteed by use of formal methods, simulation and an uncorrupted conversion of specifications into control programs.
An advanced reconfigurable controller improved by a multiple model architecture is proposed as a tool to achieve fault tolerance in complex nonlinear systems. The most complete adaptive critic design, Globalized Dual ...
详细信息
An advanced reconfigurable controller improved by a multiple model architecture is proposed as a tool to achieve fault tolerance in complex nonlinear systems. The most complete adaptive critic design, Globalized Dual Heuristic Programming (GDHP), constitutes a highly flexible nonlinear adaptive controller responsible for the generation of new control solutions for novel plant dynamics introduced by unknown faults. Working on a higher hierarchical level, the proposed supervisor makes use of two quality indexes to perform fault detection, identification and isolation based on the knowledge stored in a dynamic model bank. In the event of abrupt known faults, such knowledge is then used to greatly reduce the reconfiguration time of the GDHP controller. The synergy of the proposed supervisor and GDHP goes beyond, as solutions designed by the controller to previously unknown faults are autonomously added to the model bank. The fine interrelations among the algorithm's subsystems are illustrated in a rich numerical simulation of a MIMO nonlinear system subject to different fault scenarios.
The Self-Organizing Map (SOM) is an efficient tool for visualizing high-dimensional data. In this paper, an intuitive and effective SOM projection method is proposed for mapping high-dimensional data onto the two-dime...
详细信息
The Self-Organizing Map (SOM) is an efficient tool for visualizing high-dimensional data. In this paper, an intuitive and effective SOM projection method is proposed for mapping high-dimensional data onto the two-dimensional SOM structure with a growing self-organizing map. In the learning phase, a growing SOM is trained and the growing cell structure is used as the baseline framework. After the learning phase, the new projection method is used to map the input vector so that the input data is mapped to the structure of the SOM without having to plot the weight values, resulting in easy visualization of the data. The projection method is demonstrated on two data sets with promising results and a significantly reduced network size.
Using dimensional analysis and numerical optimisation techniques, an optimal method for tuning PID controllers for first order plus time delay systems is presented. Considering integral square error (ISE), integral ab...
详细信息
Document analysis and understanding (DAU) systems aim not only at the recognition of text but also at the extraction of relevant information out of a scanned document. Numerous studies have introduced efficient algori...
详细信息
Document analysis and understanding (DAU) systems aim not only at the recognition of text but also at the extraction of relevant information out of a scanned document. Numerous studies have introduced efficient algorithms for document analysis, some of these studies proposed an articulated and/or a translation stage. Also little work has been done in the English/Arabic (E/A) translation area. The main objective of this paper is to introduce a combination between the three trends (document understanding, E/A translation, and handling the output in articulated voice). This paper focuses on the realization of a bilingual articulated E/A system based on optical character recognition (OCR). The input of the proposed system will be an English or Arabic text through scanner or video camera;the output will be an articulated voice. The proposed scheme consists of two phases. The first phase consists of many processes, beginning with converting scanned document into an electronic processable form. Then in the segmentation step, the essential problem in Arabic OCR, that is, how to cope with the various shapes of the same character, is solved. A new methodology for segmenting Arabic characters is presented. At the end of this phase an efficient method of text recognition based on hybrid description (ANN, FFT) is used. In order to verify the performance of this phase, experiments with printed text were performed. The error rates were less than 0.1%. Results showed that the proposed scheme in this phase is very robust. In the second phase, a database with 3000 audio files was encapsulated to convert each word from the input text (the output of the first phase) to its correspondence. This research can help in many real-time applications such as: (immediate translation, machine reader for blind people, learning...).
暂无评论