Search results for "Signal"
showing 10 items of 6924 documents
A Hybrid Frequency-Space Approach for Shape Measurement by Shadow Moiré Technique with Carrier Fringe Pattern
2006
In this paper, a novel methodology to process fringe pattern is presented. The core of the signal processing technique is the use of the direction information, a modulo 2pi quantity that locally informs about the direction along which fringes grow with maximum rate. By using this information, it was possible to perform adaptive, direction- and orientation-based operations on fringe images in order to remove unwanted effects, to enhance the contrast and to extract the phase information encoded. The method has been applied on shadow moire interferograms with carrier fringes in order to measure the surface of small objects. The developed algorithm allows to process fringes whose phase informat…
Space–bandwidth product of optical signals and systems
1996
The space–bandwidth product (SW) is fundamental for judging the performance of an optical system. Often the SW of a system is defined only as a pure number that counts the degrees of freedom of the system. We claim that a quasi-geometrical representation of the SW in the Wigner domain is more useful. We also represent the input signal as a SW in the Wigner domain. For perfect signal processing it is necessary that the system SW fully embrace the signal SW.
Bluetooth-3G wireless transmission system for neural signal telemetry
2007
In this contribution a wireless transmission system for neural signals is developed. This system includes data compression algorithms at the information source, namely neural signals recorded by micro-electrode arrays. The signals are transmitted over Bluetooth to a mobile device that, without any processing or storing, retransmits it over 3G to a remote server where signal post-processing and analysis is performed. The overall transmission rate of the system is limited by the Bluetooth link between the information source and the mobile phone, as well as by the limited processing capabilities of the mobile device and also by the 3G-link. Data compression allows the transmission of up to 7 n…
Nonlinear morphological correlation: optoelectronic implementation
2008
An optoelectronic implementation of the nonlinear morphological correlation by use of a threshold-decomposition technique and a joint transform correlator architecture is presented. This nonlinear morphological correlation provides improved image detection compared with standard linear optical pattern-recognition correlation methods. It also offers a more robust detection of low-intensity images in the presence of high-intensity patterns to be rejected.
From Signal Processing to Machine Learning
2018
This chapter reviews the main landmarks of signal processing in the 20th century from the perspective of algorithmic developments. It focuses on cross‐fertilization with the field of statistical (machine) learning in the last decades. In the 21st century, model and data assumptions as well as algorithmic constraints are no longer valid, and the field of machine‐learning signal processing has erupted, with many successful stories to tell. The chapter also focuses on digital signal processing (DSP), which deals with the analysis of digitized and discrete sampled signals. Machine learning is a branch of computer science and artificial intelligence that enables computers to learn from data. Mac…
BioLab: An Educational Tool for Signal Processing Training in Biomedical Engineering
2007
This paper introduces and evaluates BioLab, a tool for teaching biosignal processing. BioLab has been used in the biomedical engineering module that is given in the second semester of the fifth year of the electronic engineering degree at the University of Valencia, Spain. This module and its correspondent curricular pathway are also reviewed. BioLab allows the results obtained with digital processing techniques to be shown interactively in the theory classes, and it also provides support in laboratory sessions. The graphic interface of BioLab simplifies its learning and use and provides access to processing and visualization functions by means of menus. The tool is based on Matlab since th…
Robust subspace DOA estimation for wireless communications
2002
This paper is concerned with array signal processing in non-Gaussian noise typical in urban and indoor radio channels. Robust and fully nonparametric high resolution algorithms for direction of arrival (DOA) estimation are presented. The algorithms are based on multivariate spatial sign and rank concepts. The performance of the algorithms is studied using simulations. The results show that almost optimal performance is obtained in wide variety of noise conditions.
A Direction/Orientation-Based Method for Shape Measurement by Shadow MoirÉ
2008
In this paper, a methodology to process fringe patterns is presented. The core of the signal processing technique is the use of the direction information, which is a modulo quantity that locally indicates the direction along which fringes grow at a maximum rate. By using this information, it was possible to perform adaptive and direction/orientation-based operations on fringe images to remove unwanted effects (mainly distortions at the image borders), to enhance the contrast, and to extract the phase information encoded. The method has been applied on shadow-moire interferograms with carrier fringes in order to measure the surface of small objects. The developed algorithm allows processing …
Active learning in digital communications with low-cost software defined radio
2021
Las comunicaciones digitales se enseñan tradicionalmente en sesiones de laboratorio desde un punto de vista teórico, utilizando plataformas de simulación. Sin embargo, el sistema de Acreditación Académica incluye la dimensión de "lo que se espera que los estudiantes sean capaces de hacer", lo que plantea la necesidad de disminuir la brecha entre las sesiones de laboratorio simuladas y un enfoque más práctico y realista. En este trabajo, proponemos una metodología para mejorar el aprendizaje de los aspectos prácticos relacionados con los cursos de Comunicaciones Digitales, así como para aumentar la motivación de los estudiantes, mediante el uso de dispositivos de radio definida por software …