Search results for "Signal"
showing 10 items of 6924 documents
On Analytical vs . Schizophrenic Procedures for Computing Music
2009
The authors present a perspective on computer music, which is based on some particular definitions of music in relation to oral culture and cybernetics. They describe some experiments with different models of neural architectures which generate original music, and then suggest that if such neural systems are rich, effective and intuitive enough to produce ‘live’ music, the understanding of their behaviour may require the development of some ‘schizophrenic’ procedures, as well as analytical ones.
Non-linear System Identification with Composite Relevance Vector Machines
2007
Nonlinear system identification based on relevance vector machines (RVMs) has been traditionally addressed by stacking the input and/or output regressors and then performing standard RVM regression. This letter introduces a full family of composite kernels in order to integrate the input and output information in the mapping function efficiently and hence generalize the standard approach. An improved trade-off between accuracy and sparsity is obtained in several benchmark problems. Also, the RVM yields confidence intervals for the predictions, and it is less sensitive to free parameter selection. Teoría de la Señal y Comunicaciones
Discrete Time Signal Processing Framework with Support Vector Machines
2007
Digital signal processing (DSP) of time series using SVM has been addressed in the literature with a straightforward application of the SVM kernel regression, but the assumption of independently distributed samples in regression models is not fulfilled by a time-series problem. Therefore, a new branch of SVM algorithms has to be developed for the advantageous application of SVM concepts when we process data with underlying time-series structure. In this chapter, we summarize our past, present, and future proposal for the SVM-DSP frame-work, which consists of several principles for creating linear and nonlinear SVM algorithms devoted to DSP problems. First, the statement of linear signal mod…
Wireless photoplethysmography finger sensor probe
2010
A sensitive, digital, wireless sensor probe has been developed for photoplethysmography (PPG) measurements. It uses standard light emitting source and detector. The main advantage of this approach is to measure discharge time of the photodiode as amplitude of PPG signal. It reduces the cost, dimensions, power consumption and filtering of the device. First results of distant monitoring of heart rate using the newly developed sensor probe are presented.
Remote Sensing of Photoplethysmogram using Multi Spot Illumination
2018
The ability to remotely extract Photoplethysmogram (PPG) signals is of great interest. A novel approach to overcome motion related noise, based on a multi spot pattern was experimentally demonstrated. Improvement of PPG signal is presented.
Advances in the Retrieval and Interpretation of Solar-Induced Vegetation Chlorophyll Fluorescence Using Passive Remote Sensing Techniques
2021
In the context of the development and implementation of the Fluorescence Explorer (FLEX) mission, selected in 2015 by the European Space Agency (ESA) as the 8th Earth Explorer, many recent developments in the field of vegetation chlorophyll fluorescence have taken place in the last years. These advances include new retrieval approaches, more accurate and robust, and a much better understanding of the variability of the signal, facilitating the interpretation of the dynamical changes and the usage of the fluorescence signal in Earth models and applications. Although chlorophyll fluorescence is related to the actual photosynthetic activity of the plants, the link between fluorescence and phot…
Data sets for energy rating of photovoltaic modules
2013
Abstract A proposal for generating standard climatic data sets for use in energy rating of photovoltaic (PV) modules is presented which will give a good comparability between different technologies. The current proposal of standard data sets consisting of “typical days” do not give realistic estimates of PV performance and thus is not sufficient as a rating standard. A dataset striking the balance between being significant for any location but does not consisting of too much data is required. A method to generate such a dataset is presented, meeting all the requirements of an international standard while being sufficiently accurate to differentiate between different devices of different man…
The influence of the stochastic features of the energy source on the design of an electromagnetic generator
2009
The purpose of this paper is to clarify in a general way how the unavoidable randomness of renewable energy sources influences the magnetic design of electric generator. A general model of electro magnetic generator based on the well known d-q axes analysis is given. The energy source is modelled as a stochastic variable and is included in the equations of the system. The equations are solved and, therefore, the energy output of the system is linked to the random characteristic of the energy source. As a result, the magnetic circuit and the parameters of the generator that maximize the energy extraction can be found and generally linked to the stochastic details of the source.
Fuel cell modelling and test: Experimental validation of model accuracy
2013
In the last few years, renewable energies have been encouraged by worldwide governments to meet energy saving policies. Among renewable energy sources, fuel cells have attracted much interest for a wide variety of research areas. Fuel cell-based residential-scaled power supply systems take advantage of simultaneous generation of power and heat, reducing the overall fossil fuel consumption and utilities cost. Modeling is one of the most important topics concerning fuel cell use. In this paper, a measurement-based steady-state and dynamic fuel cell model is presented. The proposed modelling approach is implemented on a 5kW Proton Exchange Membrane Fuel Cell. The parameters identification proc…
MATLAB-based simulator of a 5 kW fuel cell for power electronics design
2013
Abstract In the last few years, renewable energies have been encouraged by worldwide governments to meet energy saving policies. Among renewable energy sources, fuel cells have attracted much interest for a wide variety of research areas. Since combined heat-power generation is allowed, household appliances are still the most promising applications. Fuel cell-based residential-scaled power supply systems take advantage by simultaneous generation of power and heat, reducing the overall fossil fuel consumption and utilities cost. Modelling is one of the most important topic concerning fuel cell use. In this paper, a measurement-based steady-state and dynamic fuel cell model is presented. The …