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排序方式: 共有251条查询结果,搜索用时 15 毫秒
1.
Haitham Badi Sabah Hasan Hussein Sameem Abdul Kareem 《Neural computing & applications》2014,25(3-4):733-741
The main objective of this study is to explore the utility of a neural network-based approach in hand gesture recognition. The proposed system presents two recognition algorithms to recognize a set of six specific static hand gestures, namely open, close, cut, paste, maximize, and minimize. The hand gesture image is passed through three stages: preprocessing, feature extraction, and classification. In the first method, the hand contour is used as a feature that treats scaling and translation of problems (in some cases). However, the complex moment algorithm is used to describe the hand gesture and to treat the rotation problem in addition to scaling and translation. The back-propagation learning algorithm is employed in the multilayer neural network classifier. The second method proposed in this article achieves better recognition rate than the first method. 相似文献
2.
A new mathematical model of generalized thermoelasticity with memory-dependent derivatives for the dual-phase-lag heat conduction law is constructed. The governing equations of the new model are applied to a half-space subjected to ramp-type heating. Laplace transforms technique is used. The solution is obtained for different types of functions representing the thermal shock and for different values of the parameter of the time fraction derivative of the model. The effects of time-delay and arbitrary kernel function on elastic material are studied and represented graphically. The predictions of the theory are discussed and compared with dynamic classical coupled theory. 相似文献
3.
Visual Speech Synthesis by Morphing Visemes 总被引:6,自引:0,他引:6
We present MikeTalk, a text-to-audiovisual speech synthesizer which converts input text into an audiovisual speech stream. MikeTalk is built using visemes, which are a small set of images spanning a large range of mouth shapes. The visemes are acquired from a recorded visual corpus of a human subject which is specifically designed to elicit one instantiation of each viseme. Using optical flow methods, correspondence from every viseme to every other viseme is computed automatically. By morphing along this correspondence, a smooth transition between viseme images may be generated. A complete visual utterance is constructed by concatenating viseme transitions. Finally, phoneme and timing information extracted from a text-to-speech synthesizer is exploited to determine which viseme transitions to use, and the rate at which the morphing process should occur. In this manner, we are able to synchronize the visual speech stream with the audio speech stream, and hence give the impression of a photorealistic talking face. 相似文献
4.
Sherif Abdleazeem Ezzat El-Sherif 《International Journal on Document Analysis and Recognition》2008,11(3):127-141
In this paper, we fill a gap in the literature by studying the problem of Arabic handwritten digit recognition. The performances
of different classification and feature extraction techniques on recognizing Arabic digits are going to be reported to serve
as a benchmark for future work on the problem. The performance of well known classifiers and feature extraction techniques
will be reported in addition to a novel feature extraction technique we present in this paper that gives a high accuracy and
competes with the state-of-the-art techniques. A total of 54 different classifier/features combinations will be evaluated
on Arabic digits in terms of accuracy and classification time. The results are analyzed and the problem of the digit ‘0’ is
identified with a proposed method to solve it. Moreover, we propose a strategy to select and design an optimal two-stage system
out of our study and, hence, we suggest a fast two-stage classification system for Arabic digits which achieves as high accuracy
as the highest classifier/features combination but with much less recognition time. 相似文献
5.
Fault management and security of computer networks present new challenges of increasing complexity. Decision procedures for fault diagnosis, security-related threats, and follow-up actions must, however, be evaluated on the basis of sound theoretical foundations and economic costs of various strategies. This paper presents a minimum expected cost solution for fault diagnosis and corrective actions. Several notions new to fault management are introduced. The methodology is applicable to both non-malicious and malicious faults. As a novel security-related application, the problem of choosing between two strategies for containing the spread of network worms is discussed. 相似文献
6.
7.
Ayman M. Atta Hamad A. Al-Lohedan Abdelrahman O. Ezzat Zuheir A. Issa Ahmad B. Oumi 《Journal of Polymer Research》2016,23(4):69
In this work, we aimed to develop a feasible method for in situ preparation of a magnetite ionic polymer nanocomposite at room temperature. For this purpose, acrylonitrile (AN) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomers were copolymerized and crosslinked using different monomer mol ratios in the presence of N,N-methylenebisacrylamide (MBA) as crosslinker to produce ionic crosslinked polymers P(AN-co-AMPS. The nitrile groups were converted to amine amidoxime by reacting with hydroxylamine to increase the adsorption characteristics of the ionic polymers. The produced polymers were swelled in iron cations produced from the reaction of ferric chloride and potassium iodide, followed by reaction with an ammonium hydroxide solution to produce magnetite nano-polymer composites. We performed FT-IR and XRD analysis to determine the chemical and crystalline structures, and assessed the morphologies and magnetite content using SEM, TEM and TGA analyses. We investigated the adsorption capacity and mechanism of the prepared magnetite nano-composites as adsorbents for methylene blue, Co2+ and Ni2+ cations from water. 相似文献
8.
Werner Schroth Ronald Spitzner Mounifa M. Ezzat Monika Richter Sabine Freitag 《Advanced Synthesis \u0026amp; Catalysis》1990,332(2):148-160
On the Existence of 2-Imino-2H-1,3-thiazines The title compounds 2 are readily liberated from the 2-amino-1,3-thiazinium salts 1 by treatment with bases. Their stability depends sensitively on the substituents at the imino-N. The imino-N substituted 2a – i are isolable as well-defined coloured substances. Reaction of the 2 as well 1 with nucleophilic agents affords pyrimidine-2-thiones ( 4 , 9 – 11 , 16 – 18 ). In these ring transformations a nucleophilic addition at ring position 6 as primary reaction step is preferred. The imino-N unsubstituted representatives display a more complicated behaviour; the highly enhanced reactivity prevents or handicaps, respectively, any isolation. As exemplified in the base-induced ring-transformation of 1 m to the pyrimidine derivative 19 , these 2 are able to react as nucleophiles too, and versatile intermolecular self-reactions are increasingly favoured. 相似文献
9.
Vahid Heydari Fami Tafreshi Ebrahim Ghazisaeedi Haitham Cruickshank Zhili Sun 《中兴通讯技术(英文版)》2014,(2):41-49
Network securityprotocolssuch as IPsechave been used for many years to ensure robust end-to-end communication and are impor-tant in the context of SDN.Despite the widespread installation of IPsec to date,per-packet protection offered by the protocol isnot very compatible with OpenFlow and flow-like behavior.OpenFlow architecture cannot aggregate IPsec-ESP flows in transportmode or tunnel mode because layer-3 information is encrypted and therefore unreadable.In this paper,we propose using the Secu-rity Parameter Index(SPI)of IPsec within the OpenFlow architecture to identify and direct IPsec flows.Thisenables IPsec to con-form to the packet-based behavior of OpenFlow architecture.In addition,by distinguishing between IPsec flows,the architectureis particularly suited to secure group communication. 相似文献
10.
The measurement of transportation network travel time reliability is imperative to provide drivers with accurate route guidance information and to generate the shortest path (or alternative paths) connecting origins and destinations, especially under conditions of varying demands and limited capacities. Previous studies assumed that link failures in a road network are statistically independent and that reliability probabilities are perfectly determinable. In real life, these assumptions are dubious, because the failure of a link in one particular area does not necessarily result in the complete failure of the neighboring link, but may lead to deterioration of its performance. This paper presents a new methodology to study the multistate system reliability analysis of transportation networks for which one cannot formulate an “all or nothing” type of failure criterion and in which dependent link failures are considered. The methodology is presented, using a numerical example, for computing the probability that travel time between an origin and a destination may exceed a threshold. 相似文献