3,114 research outputs found
Image enlargement as an edge estimation
A robust image enlargement algorithm is presented in this paper. We formulate the image enlargement process as an edge information estimation process. In order to achieve a higher resolution, we first perform Pixel Duplication on the target image to form an initial high resolution image. Then the edge details of the enlarged image are estimated by using a novel neural network called "Agent Swarm Regression Network ASRN", which is trained by a set of low resolution (LR) / high resolution (HR) image patch pairs. Two benchmark images were used to verify the performance of the proposed algorithm. The results show that the enlarged images by the proposed algorithm are sharper than those by the conventional methods.published_or_final_versio
Sequential RBF function estimator: memory regression network
The newal-network training algorithm can be divided into 2 categories: (I) Batch mode and (2) Sequential mode. In this paper, a novel online RBF network called "Memory Regression Network (MRN)" is proposed. Different from the previous approaches [2, 11], MRN involves two types of memories: Experience and Neuron, which handle short and long term memories respectively. By simulating human's learning behavior, a given function can be estimated without memorizing the whole training set. Two sets of function estimation experiments are examined in order to illustrate the performance of the proposed algorithm. The results show that MRN can effectively approximate the given function within a reasonable time and acceptable mean square error. © 2004 IEEE.published_or_final_versio
Agent swarm classification network ASCN
In this paper we introduced a newly RBF Classification Network - "Agent Swarm Classification Network ASCN", which is trained by a Multi-agent systems (MAS) approach. MAS can be regarded as a swarm of independent software agents interact with each other to achieve common goals, complete concurrent distributed tasks under autonomous control. By treating each neuron as an agent, the weights of neurons can be determined through a set of pre-defined simple agent behavior. Three sets of experiments are examined to observe the effectiveness of the proposed method. © 2004 IEEE.published_or_final_versio
Response knowledge learning of autonomous agent
In robot applications, the performance of a robot agent is measured by the quantity of award received from its response. Many literatures [1-5] define the response as either a state diagram or a neural network. Due to the absence of a desired response, neither of them is applicable to an unstructural environment. In this paper, a novel Response Knowledge Learning algorithm is proposed to handle this domain. By using a set of experiences, the algorithm can extract the contributed experiences to construct the response function. Two sets of environments are provided to illustrate the performance of the proposed algorithm. The results show that it can effectively construct the response function that receives an award which is very close to the true maximum.published_or_final_versio
Agent swarm regression network ASRN
A multi-agent system (MAS), with independent software agents interacting with each other to achieve common goals will complete concurrent distributed tasks under autonomous control. In this paper, novel RBF Regression Network - "Agent Swarm Regression Network ASRN" is proposed and will be trained by a MAS. Each neuron of the ASRN is considered as an agent, which consists of per-deflned simple agent behavior set. After a sufficient number of iterations, the weights of neurons can be determined. Two sets of experiment will be examined to observe the effectiveness of the proposed method. © 2004 IEEE.published_or_final_versio
Search for a simultaneous signal from small transient events in the Pierre Auger Observatory and the Tupi muon telescopes
We present results of a search for a possible signal from small scale solar
transient events (such as flares and interplanetary shocks) as well as possible
counterparts to Gamma-Ray Burst (GRB) observed simultaneously by the Tupi muon
telescope Niteroi-Brazil, 22.90S, 43.20W, 3 m above sea level) and the Pierre
Auger Observatory surface detectors (Malargue-Argentina, 69.30S, 35.30W,
altitude 1400 m). Both cosmic ray experiments are located inside the South
Atlantic Anomaly (SAA) region. Our analysis of several examples shows
similarities in the behavior of the counting rate of low energy (above 100 MeV)
particles in association with the solar activity (solar flares and
interplanetary shocks). We also report an observation by the Tupi experiment of
the enhancement of muons at ground level with a significance higher than 8
sigma in the 1-sec binning counting rate (raw data) in close time coincidence
(T-184 sec) with the Swift-BAT GRB110928B (trigger=504307). The GRB 110928B
coordinates are in the field of view of the vertical Tupi telescope, and the
burst was close to the MAXI source J1836-194. The 5-min muon counting rate in
the vertical Tupi telescope as well as publicly available data from Auger (15
minutes averages of the scaler rates) show small peaks above the background
fluctuations at the time following the Swift-BAT GRB 110928B trigger. In
accordance with the long duration trigger, this signal can possibly suggest a
long GRB, with a precursor narrow peak at T-184 sec.Comment: 9 pages, 13 figure
Coulomb Drag near the metal-insulator transition in two-dimensions
We studied the drag resistivity between dilute two-dimensional hole systems,
near the apparent metal-insulator transition. We find the deviations from the
dependence of the drag to be independent of layer spacing and
correlated with the metalliclike behavior in the single layer resistivity,
suggesting they both arise from the same origin. In addition, layer spacing
dependence measurements suggest that while the screening properties of the
system remain relatively independent of temperature, they weaken significantly
as the carrier density is reduced. Finally, we demonstrate that the drag itself
significantly enhances the metallic dependence in the single layer
resistivity.Comment: 6 pages, 5 figures; revisions to text, to appear in Phys. Rev.
Reorientation of Anisotropy in a Square Well Quantum Hall Sample
We have measured magnetotransport at half-filled high Landau levels in a
quantum well with two occupied electric subbands. We find resistivities that
are {\em isotropic} in perpendicular magnetic field but become strongly {\em
anisotropic} at = 9/2 and 11/2 on tilting the field. The anisotropy
appears at an in-plane field, 2.5T, with the easy-current
direction {\em parallel} to but rotates by 90 at 10T and points now in the same direction as in single-subband samples.
This complex behavior is in quantitative agreement with theoretical
calculations based on a unidirectional charge density wave state model.Comment: 4 pages, 4 figure
Zener Tunneling Between Landau Orbits in a High-Mobility Two-Dimensional Electron Gas
Magnetotransport in a laterally confined two-dimensional electron gas (2DEG)
can exhibit modified scattering channels owing to a tilted Hall potential.
Transitions of electrons between Landau levels with shifted guiding centers can
be accomplished through a Zener tunneling mechanism, and make a significant
contribution to the magnetoresistance. A remarkable oscillation effect in weak
field magnetoresistance has been observed in high-mobility 2DEGs in
GaAs-AlGaAs heterostructures, and can be well explained by the
Zener mechanism.Comment: 5 pages, 4 figures. Text slightly shortened, figures resize
Field-induced breakdown of the quantum Hall effect
A numerical analysis is made of the breakdown of the quantum Hall effect
caused by the Hall electric field in competition with disorder. It turns out
that in the regime of dense impurities, in particular, the number of localized
states decreases exponentially with the Hall field, with its dependence on the
magnetic and electric field summarized in a simple scaling law. The physical
picture underlying the scaling law is clarified. This intra-subband process,
the competition of the Hall field with disorder, leads to critical breakdown
fields of magnitude of a few hundred V/cm, consistent with observations, and
accounts for their magnetic-field dependence \propto B^{3/2} observed
experimentally. Some testable consequences of the scaling law are discussed.Comment: 7 pages, Revtex, 3 figures, to appear in Phys. Rev.
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