Search results for "Manipulation"
showing 10 items of 311 documents
CliffoSor: A Parallel Embedded Architecture for Geometric Algebra and Computer Graphics
2006
Geometric object representation and their transformations are the two key aspects in computer graphics applications. Traditionally, compute-intensive matrix calculations are involved to model and render 3D scenery. Geometric algebra (a.k.a. Clifford algebra) is gaining growing attention for its natural way to model geometric facts coupled with its being a powerful analytical tool for symbolic calculations. In this paper, the architecture of CliffoSor (Clifford Processor) is introduced. ClifforSor is an embedded parallel coprocessing core that offers direct hardware support to Clifford algebra operators. A prototype implementation on an FPGA board is detailed. Initial test results show more …
Inversion of matrix pencils for generalized systems
1993
Abstract This paper clarifies the nature of the Leverrier-Faddeev algorithm for generalized and state-space systems. It presents useful diagrams for recursive computation of the coefficients of the characteristic polynomial and the coefficient matrices of the adjoint matrix for various matrix pencils. A simplified case covers recursive equations and diagrams for inversion of the second-order matrix pencil (Es2 + A1s + A0) where E may be singular. The appendix provides two examples of mechanical and heat exchange systems which can be described by the generalized models.
The Psychological Science Accelerator’s COVID-19 rapid-response dataset
2023
Funder: Amazon Web Services (AWS) Imagine Grant
A more efficient second order blind identification method for separation of uncorrelated stationary time series
2016
The classical second order source separation methods use approximate joint diagonalization of autocovariance matrices with several lags to estimate the unmixing matrix. Based on recent asymptotic results, we propose a novel unmixing matrix estimator which selects the best lag set from a finite set of candidate sets specified by the user. The theory is illustrated by a simulation study.
Higher order matrix differential equations with singular coefficient matrices
2015
In this article, the class of higher order linear matrix differential equations with constant coefficient matrices and stochastic process terms is studied. The coefficient of the highest order is considered to be singular; thus, rendering the response determination of such systems in a straightforward manner a difficult task. In this regard, the notion of the generalized inverse of a singular matrix is used for determining response statistics. Further, an application relevant to engineering dynamics problems is included.
Environment, information, fake news. Information Disorder. Learning to Recognize Fake News. Fake News
2022
Although more than 25 years have passed since the publication of a report that clearly shows the scientific evidence on global warming and the influence of human activity, today there are still thousands of fake news stories circulating on the web. Lobbies have always used the media to discredit science, and with the boom in social media this strategy has shifted online. Deniers single out items of scientific truth and use them instrumentally to render fake news credible. After years of a widespread lack of control, something is changing: since 2020, Facebook has created the "Climate Science Information Center", a platform that signals fake climate news and encourages people to consult offi…
epiModel: A system to build automatically systems of differential equations of compartmental type-epidemiological models
2011
In this paper we describe epiModel, a code developed in Mathematica that facilitates the building of systems of differential equations corresponding to type-epidemiological linear or quadratic models whose characteristics are defined in text files following an easy syntax. It includes the possibility of obtaining the equations of models involving age and/or sex groups. © 2011.
First-year university students making sense of symbols in integration
2020
International audience; This paper focuses on first year university engineering students and their sensemaking of integration and its symbolism. Through a semiotic approach, attention is given to two students and their attempt to verbally express their reflections on integration and the related meaning of symbols. Findings suggest that students tend to interpret the symbols mainly as operations, in terms of calculations to be carried out. They express uncertainty concerning what the symbols stand for, and the mathematical objects they represent. For example, the symbols ∫ and are respectively conceived of as “finding the integral with respect to x” and students are unclear on how Riemann su…
More Power through Symbolic Computation: Extending Stata by using the Maxima Computer algebra system
2015
Maxima is a free and open-source computer algebra system that can perform symbolic computations such as solving equations, determining derivatives of functions, obtaining Taylor series, and manipulating algebraic expressions. In this article, I present the Maxima Bridge System, which is a collection of software programs that allows Stata to interface with Maxima so that Maxima can be used for symbolic computation to transfer data from Stata to Maxima and to retrieve results from Maxima. The cooperation between Stata and Maxima provides an environment for statistical analysis in which symbolic computation can be easily used together with all the facilities supplied by Stata. In this environ…
MOESM2 of Global mapping of randomised trials related articles published in high-impact-factor medical journals: a cross-sectional analysis
2020
Additional file 2. Data extraction and normalisation processes.