The multimodal and time-varying aspects of blind equalization problems in communication systems are treated here by means of an immune-inspired strategy capable of estimating the coefficients of the FIR equalization f...
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The multimodal and time-varying aspects of blind equalization problems in communication systems are treated here by means of an immune-inspired strategy capable of estimating the coefficients of the FIR equalization filter in an unsupervised manner. The associated optimization problem is solved by means of a population-based search technique characterized by a dynamic control of the population size and diversity maintenance. Static and time-varying channels have been proposed in simulated scenarios, aiming at indicating the tracking capability derived from the adaptive adjustment of the coefficients of the blind equalizer
The dynamics of oxidation of aluminum nanoclusters (20nm diameter) is investigated using a parallel molecular dynamics approach based on variable charge interatomic interactions due to Streitz and Mintmire that includ...
The dynamics of oxidation of aluminum nanoclusters (20nm diameter) is investigated using a parallel molecular dynamics approach based on variable charge interatomic interactions due to Streitz and Mintmire that include both ionic and covalent effects. Simulations are performed for both canonical ensembles for molecular oxygen (O2) environments and microcanonical ensembles for molecular (O2) and atomic (O1) oxygen environments. Structural and dynamic correlations in the oxide region are calculated, as well as the evolution of charges, surface oxide thickness, diffusivities of atoms, and local stresses. In the microcanonical ensemble, the oxidizing reaction becomes explosive in both molecular and atomic oxygen environments due to the enormous energy release associated with Al−O bonding. Local stresses in the oxide scale cause rapid diffusion of aluminum and oxygen atoms. Analyses of the oxide scale reveal significant charge transfer and a variation of local structures from the metal-oxide interface to the oxide-environment interface. In the canonical ensemble, oxide depth grows linearly in time until ∼30ps, followed by saturation of oxide depth as a function of time. An amorphous oxide layer of thickness ∼40Å is formed after 466ps, in good agreement with experiments. The average mass density in the oxide scale is 75% of the bulk alumina density. Evolution of structural correlation in the oxide is analyzed through radial distribution and bond angles. Through detailed analyses of the trajectories of O atoms and their formation of OAln structures, we propose a three-step process of oxidative percolation that explains deceleration of oxide growth in the canonical ensemble.
Active learning enables learners to actively engage in learning. Learning not only transfers material to students for learning, but also encourages greater mental engagement and more extensive student-student and stud...
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Active learning enables learners to actively engage in learning. Learning not only transfers material to students for learning, but also encourages greater mental engagement and more extensive student-student and student-instructor interaction than does a typical lecture class. Peer instruction (PI) engages students in active learning by achieving continuous instructor-student interaction in a physics lecture. However, the methodologies and the effectiveness of implementing PI for elementary school students have seldom been clarified. This study explores the possibility of adopting PI in an elementary science classroom. The research considerations of the study are as follows: (1) how wireless technology can enhance PI in elementary science classroom; (2) how a teacher can engage students in pre-class reading, and (3) whether elementary school students have sufficient social skills to perform a PI discussion? These questions are examined by observing how the PI pedagogical model worked with a wireless response system in elementary science classroom. Based on the observation, this study also proposes a way of improving the PI learning experience of elementary school students by adding experiments and observations during peer discussion to explain concepts and phenomena in physics.
作者：
De Brito, Halisson MatosStrauch, JuliaDe Souza, Jano MoreiraOsthoff, CarlaCOPPE/UFRJ
Systems Engineering and Computer Science Program Federal University of Rio de Janeiro PO Box 68511 ZIP Code: 21945-970 Rio de Janeiro RJ Brazil ENCE /IBGE
National School of Statistical Sciences 106 S. 401 ZIP Code: 20231-050 R. André Cavalcanti Rio de Janeiro RJ Brazil LNCC
National Laboratory for Scientific Computing Av. Getulio 333 Quitandinha Vargas Petrópolis RJ Brazil IM/UFRJ
Institute of Mathematics Federal University of Rio de Janeiro PO Box 68511 ZIP Code: 21945-970 Rio de Janeiro RJ Brazil
This paper presents MODENA, an architecture for scientific models management using Computational Grid platform. This architecture is comprised of two systems: ModManager and ModRunner. ModManager deals with knowledge ...
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This paper presents MODENA, an architecture for scientific models management using Computational Grid platform. This architecture is comprised of two systems: ModManager and ModRunner. ModManager deals with knowledge management about scientific models, acting as a scientific models library allowing for cataloguing, searching, reutilization and generation of new models. To achieve this, a metamodel is proposed to classify models, in order to support the organization, searching and retrieving of models. ModRunner manages the execution of models in a Grid environment allowing for model composition to generate a scientific Grid Workflow to be executed by distributed services offered by Grid Services. An initial prototype of ModManager is presented.
H.264/AVC is a new international standard for the compression of natural video images, in which a deblocking filter has been adopted to remove blocking artifacts. In this paper, we propose an efficient processing orde...
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In this paper, a vision-based medium vocabulary Chinese sign language recognition (SLR) system is presented. The proposed recognition system consists of two modules. In the first module, techniques of robust hands det...
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ISBN:
(纸本)1581139543
In this paper, a vision-based medium vocabulary Chinese sign language recognition (SLR) system is presented. The proposed recognition system consists of two modules. In the first module, techniques of robust hands detection, background subtraction and pupils detection are efficiently combined to precisely extract the feature information with the aid of simple colored gloves in the unconstrained environment. Meanwhile, an effective and efficient hierarchical feature description scheme with different scale features to characterize sign language is proposed, where principal component analysis (PCA) is employed to characterize the finger features more elaborately. In the second part, a Tied-Mixture Density Hidden Markov Models (TMDHMM) framework for SLR is proposed, which can speed up the recognition without the significant loss of recognition accuracy compared with the continuous hidden Markov models (CHMM). Experimental results based on 439 frequently used Chinese sign language (CSL) words show that the proposed methods can work well for the medium vocabulary SLR in the environment without special constraints and the recognition accuracy is up to 92.5%. Copyright 2004 ACM.
A data model supporting the unification of the management of temporal XML document databases and version control, i.e., a Temporal Version Data Model (TVDM), is proposed. TVDM is temporally change-centric and represen...
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Creativity has become an important asset in today'sfast changing environment. It is especially important indesign, which demands innovative solutions for *** believe that creativity can and should beencouraged in ...
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Creativity has become an important asset in today'sfast changing environment. It is especially important indesign, which demands innovative solutions for *** believe that creativity can and should beencouraged in work groups. In this paper, we proposea framework for supporting creativity in problemsolving. Through the use of problem, domain and usermodels and information retrieval and agent technology,we hope to support creative cooperative work.
The simulation and analysis of human motion is a popular issue in simulation area. It is highly valued in sport motion training and analysis. A method based on computer vision technologies is presented to achieve the ...
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ISBN:
(纸本)0780384075
The simulation and analysis of human motion is a popular issue in simulation area. It is highly valued in sport motion training and analysis. A method based on computer vision technologies is presented to achieve the function that the simulated motion in sport simulation system and the motion in sport video are presented on UK same screen and at die same view point. So we can quickly and accurately find UK difference between the athlete motion in sport video and the simulated motion. It is very helpful to the training of athletes.
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