Search results for "Compres"
showing 10 items of 1107 documents
Introduction to Digital Signal Processing
2018
Signal processing deals with the representation, transformation, and manipulation of signals and the information they contain. Typical examples include extracting the pure signals from a mixture observation (a field commonly known as deconvolution) or particular signal (frequency) components from noisy observations (generally known as filtering). This chapter outlines the basics of signal processing and then introduces the more advanced concepts of time‐frequency and time‐scale representations, as well as emerging fields of compressed sensing and multidimensional signal processing. When moving to multidimensional signal processing, a modern approach is taken from the point of view of statis…
Design of Multiresolution Operators Using Statistical Learning Tools: Application to Compression of Signals
2012
Using multiresolution based on Harten's framework [J. Appl. Numer. Math., 12 (1993), pp. 153---192.] we introduce an alternative to construct a prediction operator using Learning statistical theory. This integrates two ideas: generalized wavelets and learning methods, and opens several possibilities in the compressed signal context. We obtain theoretical results which prove that this type of schemes (LMR schemes) are equal to or better than the classical schemes. Finally, we compare traditional methods with the algorithm that we present in this paper.
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…
An enhanced random walk algorithm for delineation of head and neck cancers in PET studies
2017
An algorithm for delineating complex head and neck cancers in positron emission tomography (PET) images is presented in this article. An enhanced random walk (RW) algorithm with automatic seed detection is proposed and used to make the segmentation process feasible in the event of inhomogeneous lesions with bifurcations. In addition, an adaptive probability threshold and a k-means based clustering technique have been integrated in the proposed enhanced RW algorithm. The new threshold is capable of following the intensity changes between adjacent slices along the whole cancer volume, leading to an operator-independent algorithm. Validation experiments were first conducted on phantom studies:…
Performance Prevision of a Turbocharged Natural Gas Fuelled S.I. Engine
2008
Natural gas represents today maybe the most valid alternative to conventional fuels for road vehicles propulsion. The main constituent of natural gas, methane, is characterized by a high autoignition temperature, which makes the fuel highly resistant to knocking: this allows a considerable downsizing of the engine by means of supercharging even under high compression ratio. Starting from these considerations, the authors realized a thermodynamic model of a 4-cilynder s.i. engine for the prevision of in-cylinder pressure, employing a two-zone approach for the combustion and adding sub-models to account for gas properties change and knocking occurrence. An extensive experimental campaign has …
Implementation of JPEG2000 arithmetic decoder using dynamic reconfiguration of FPGA
2005
This paper describes implementation of a part of JPEG2000 algorithm (MQ-Decoder and arithmetic decoder) on a FPGA board using dynamic reconfiguration. Comparison between static and dynamic reconfiguration is presented and new analysis criteria (time performance, logic cost, spatio-temporal efficiency) are defined. MQ-decoder and arithmetic decoder can be classified in the most attractive case for dynamic reconfiguration implementation: applications without parallelism by functions. This implementation is done on an architecture designed to study dynamic reconfiguration of FPGAs: the ARDOISE architecture. The implementation obtained, based on four partial configurations of arithmetic decoder…
MultiSlice human organ extraction based on GVF
2008
Segmentation techniques based on active contours algorithm are widely used in medical imaging. Unfortunately, they require a lot of parameters to be used and this can rep- resent an issue for those physicians with not much informatics skills. This paper proposes a software tool which allows to segment multiple slice can differ organ extraction setting a small number of parameters. Moreover, the tool offers the functionality to perform a multiple segmentation the same time, so that an entire volume composed by hundreds slices can be segmented.
Optimization criteria in sample selection step of local regression for quantitative analysis of large soil NIRS database
2012
International audience; Large soil spectral libraries compiling thousands of NIR (Near Infrared) reflectance spectra have been created encompassing a wide diversity and heterogeneity of spectra. Among the many chemometric approaches to the calibration of chemical and physical properties from these large libraries, local calibrations have the advantage of being able to select the most similar spectra to the spectrum of a target sample. This is particularly relevant when dealing with highly heterogeneous media such as soils, where the mineral matrix has a strong influence on spectral features. A crucial step in the implementation of local calibration procedures is the construction of local ne…
Suffix array and Lyndon factorization of a text
2014
Abstract The main goal of this paper is to highlight the relationship between the suffix array of a text and its Lyndon factorization. It is proved in [15] that one can obtain the Lyndon factorization of a text from its suffix array. Conversely, here we show a new method for constructing the suffix array of a text that takes advantage of its Lyndon factorization. The surprising consequence of our results is that, in order to construct the suffix array, the local suffixes inside each Lyndon factor can be separately processed, allowing different implementative scenarios, such as online, external and internal memory, or parallel implementations. Based on our results, the algorithm that we prop…
Tecnica del sovracarotaggio per pilastri compressi in c.a.
2010
The paper shows the results of an experimental investigation on the behaviour of compressed concrete columns subjected to the overcoring technique. Extraction of cylindrical concrete cores in perpendicular direction to the column surface, was achieved by rotary drilling using a diamond tipped hollow barrel. Core is gradually isolated from the stress field in the surrounding concrete and at every advancing step the re-equilibrium deformation response is measured by means of four strain-gauges, placed on its external surface and near the hole. Finally the original stress state is computed in the elastic phase on the basis of recorded strains, knowing the elastic properties of concrete and by …