Search results for "Mathematica"
showing 10 items of 7971 documents
Modelling of Non-WSSUS Channels with Time-Variant Doppler and Delay Characteristics
2018
This paper deals with the modelling of non-wide-sense stationary uncorrelated scattering (non-WSSUS) channels in which the angles of arrival (AOAs), Doppler frequencies, and propagation delays vary with time. Starting from a geometrical model in which the mobile station (MS) travels along a predefined path with time-variant velocity, it is shown how the parameters of the non-WSSUS model can be computed analytically assuming that the scatterers are fixed. One of the key results of our analysis is that the time-variant Doppler frequencies and the time-variant propagation delays of WSSUS and non-WSSUS channels are connected by a fundamental relationship. Furthermore, the time-variant channel t…
A Musical Pattern Discovery System Founded on a Modeling of Listening Strategies
2004
Music is a domain of expression that conveys a paramount degree of complexity. The musical surface, composed of a multitude of notes, results from the elaboration of numerous structures of different types and sizes. The composer constructs this structural complexity in a more or less explicit way. The listener, faced by such a complex phenomenon, is able to reconstruct only a limited part of it, mostly in a non-explicit way. One particular aim of music analysis is to objectify such complexity, thus offering to the listener a tool for enriching the appreciation of music (Lartillot and SaintJames, 2004). The trouble is, traditional musical analysis, although offering a valuable understanding …
Testing for goodness rather than lack of fit of continuous probability distributions.
2021
The vast majority of testing procedures presented in the literature as goodness-of-fit tests fail to accomplish what the term is promising. Actually, a significant result of such a test indicates that the true distribution underlying the data differs substantially from the assumed model, whereas the true objective is usually to establish that the model fits the data sufficiently well. Meeting that objective requires to carry out a testing procedure for a problem in which the statement that the deviations between model and true distribution are small, plays the role of the alternative hypothesis. Testing procedures of this kind, for which the term tests for equivalence has been coined in sta…
Aprendiendo Vibraciones Mec´anicas con Wolfram Mathematica
2015
[EN] Mechanical vibrations as subject can be found within many Engineering and Science Degrees. To achieve that the students understand the mathematics and its physical interpretation is the objective we should get as docents. In this paper we describe how to create a simple graphical model of a single degree of freedom vibrating system allowing us to visualize concepts like above concepts damping, resonance or forced vibrations. For that, we use the popular symbolic software Wolfram Mathematica with which, without an excessive programming complexity, we can obtain a very satisfactory visual model capable to move itself, controlled by parameters. In addition, the model incorporates the curv…
Grammars++ for modelling information in text
1999
Abstract Grammars provide a convenient means to describe the set of valid instances in a text database. Flexibility in choosing a grammar can be exploited to provide information modelling capability by designing productions in the grammar to represent entities and relationships of interest to database applications. Additional constraints can be specified by attaching predicates to selected nonterminals in the grammar. When used for database definition, grammars can provide the functionality that users have come to expect of database schemas. Extended grammars can also be used to specify database manipulation, including query, update, view definition, and index specification.
Predicting perceived visual complexity of abstract patterns using computational measures: The influence of mirror symmetry on complexity perception
2017
Visual complexity is relevant for many areas ranging from improving usability of technical displays or websites up to understanding aesthetic experiences. Therefore, many attempts have been made to relate objective properties of images to perceived complexity in artworks and other images. It has been argued that visual complexity is a multidimensional construct mainly consisting of two dimensions: A quantitative dimension that increases complexity through number of elements, and a structural dimension representing order negatively related to complexity. The objective of this work is to study human perception of visual complexity utilizing two large independent sets of abstract patterns. A w…
A non-stationary multipath fading channel model incorporating the effect of velocity variations of the mobile station
2014
A standard assumption in mobile fading channel modelling is that the mobile station (MS) moves along a straight line with constant speed. In practice, this assumption is violated in most propagation scenarios. For the development of more realistic channel models, it is therefore important to relax this restriction by allowing the MS to change its velocity. In this paper, we study the effect of velocity changes on the statistical properties of multipath fading channels. Expressions will be derived for the local autocorrelation function (ACF), the Wigner-Ville spectrum, the average Doppler shift, and the Doppler spread. Our findings show that a variation of the speed and/or the direction of t…
A combined analysis to extract objects in remote sensing images
1999
Abstract This paper describes an object recognition system to extract shape information from remote sensing images. One of the goals is to determine if towers and power lines can be seen on one-meter imagery and how much ground conditions can influence the resolution power of the recognition algorithms. To this end, an integrated analysis system has been implemented inside the Remote Sensing Imaging System (RSIS). The methodology consists in the combination of statistical and structural information. It has been tested on real images and it will be integrated in an automatic system for the assessment of post storm damage.
Protein data condensation for effective quaternary structure classification
2007
Many proteins are composed of two or more subunits, each associated with different polypeptide chains. The number and the arrangement of subunits forming a protein are referred to as quaternary structure. The quaternary structure of a protein is important, since it characterizes the biological function of the protein when it is involved in specific biological processes. Unfortunately, quaternary structures are not trivially deducible from protein amino acid sequences. In this work, we propose a protein quaternary structure classification method exploiting the functional domain composition of proteins. It is based on a nearest neighbor condensation technique in order to reduce both the porti…
The Detector Control of the PANDA Experiment
2014
The PANDA experiment will be built at the antiproton storage ring HESR, a part of the new accelerator facility FAIR in Darmstadt, Germany. PANDA aims amongst other topics for high precision measurements in hadron spectroscopy and search for exotic matter. To guarantee the high resolution of the different components a detector control system (DCS) monitoring temperatures, humidity, pressure, and controlling chillers and power supplies is needed. The DCS of PANDA is built using the open-source software package EPICS (Experimental Physics and Industrial Control System) with a PANDA specific version of Control-System Studio. In this document the general concepts of the PANDA DCS will be discuss…