Search results for "online"
showing 10 items of 4526 documents
On the application of the generalized means to construct multiresolution schemes satisfying certain inequalities proving stability
2021
Multiresolution representations of data are known to be powerful tools in data analysis and processing, and they are particularly interesting for data compression. In order to obtain a proper definition of the edges, a good option is to use nonlinear reconstructions. These nonlinear reconstruction are the heart of the prediction processes which appear in the definition of the nonlinear subdivision and multiresolution schemes. We define and study some nonlinear reconstructions based on the use of nonlinear means, more in concrete the so-called Generalized means. These means have two interesting properties that will allow us to get associated reconstruction operators adapted to the presence o…
Intertwining operators between different Hilbert spaces: connection with frames
2009
In this paper we generalize a strategy recently proposed by the author concerning intertwining operators. In particular we discuss the possibility of extending our previous results in such a way to construct (almost) isospectral self-adjoint operators living in different Hilbert spaces. Many examples are discussed in details. Many of them arise from the theory of frames in Hilbert spaces, others from the so-called g-frames.
Active Disturbance Rejection Control of Synchronous Reluctance Motors
2020
This paper describes how the ADRC (Active Disturbance Rejection Control) strategy can be successfully applied to SynRM (Synchronous Reluctance Motor) drives. The ADRC is an adaptive robust extension of the input-output Feedback Linearization Control (FLC). Its main feature is that the nonlinear transformation of the state is computed on-line and not by using the model. As a consequence, any unmodelled dynamics or uncertainty of the parameters can be addressed. The control strategy has been verified successfully with experimental tests confirming the high dynamic response of the drive.
Relation between adaptive learning actions and profiles of MOOCs users
2016
The overcrowding and the heterogeneity of participants' profiles in a Massive Open Online Course (MOOC) are some of the main causes for a high dropout rate. International reports and research works points out the personalized learning as an important way to improve learning in any educational context. The information and communication technologies help to address adaptive technics in education through online courses. The specific characteristics of MOOCs point to the need to implement adaptive methodologies in MOOCs to increase the completion rates. This work presents a statistical analysis to find out in what aspects the condition of adaptivity, defined by the construct, is a preference of…
Design, Control, and Analysis of Nonlinear Circuits with Tunnel Diode with Piecewise Affine Dynamics
2019
Statistical geometric affinity in human brain electric activity
2007
10 pages, 9 figures.-- PACS nrs.: 87.19.La; 05.45.Tp.-- ISI Article Identifier: 000246890100105
Analysis of block random rocking on nonlinear flexible foundation
2020
Abstract In this paper the rocking response of a rigid block randomly excited at its foundation is examined. A nonlinear flexible foundation model is considered accounting for the possibility of uplifting in the case of strong excitation. Specifically, based on an appropriate nonlinear impact force model, the foundation is treated as a bed of continuously distributed springs in parallel with nonlinear dampers. The statistics of the rocking response is examined by an analytical procedure which involves a combination of static condensation and stochastic linearization methods. In this manner, repeated numerical integration of the highly nonlinear differential equations of motion is circumvent…
CLUSTER MONTE CARLO ALGORITHMS IN STATISTICAL MECHANICS
1992
The cluster Monte Carlo method, where variables are updated in groups, is very efficient at second order phase transitions. Much better results can be obtained with less computer time. This article reviews the method of Swendsen and Wang and some of its applications.
A Measurement System for Power Inductors in Non-Linear Operating Conditions
2021
The exploitation of power inductors in switching converters outside the linear region requires detailed information on the magnetization curve that often is not included among those usually available on their datasheets. This paper proposes an automatic system in which the inductor is characterized in real operating conditions taking into account also the core temperature. It is based on a switching converter suitably controlled by a virtual instrument. The system was tested by retrieving the inductance vs current curves of two commercial inductors for core temperatures up to 105°C, showing the different behaviors of the magnetization curves. Results are coherent with data given by manufact…
Robustness of 40 Gb/s ASK modulation formats in the practical system infrastructure.
2006
In this work, we analyzed by means of numerical and laboratory experiments the resilience of 40 Gb/s amplitude shift keying modulation formats to transmission impairments in standard single-mode fiber lines as well as to optical filtering introduced by the optical add/drop multiplexer cascade. Our study is a pre-requisite to assess the implementation of cost-effective 40 Gb/s modulation technology in next generation high bit-rate robust optical transport networks. © 2006 Optical Society of America.