Search results for " Matrix"
showing 10 items of 2053 documents
Conformal measures for multidimensional piecewise invertible maps
2001
Given a piecewise invertible map T:X\to X and a weight g:X\rightarrow\ ]0,\infty[ , a conformal measure \nu is a probability measure on X such that, for all measurable A\subset X with T:A\to TA invertible, \nu(TA)= \lambda \int_{A}\frac{1}{g}\ d\nu with a constant \lambda>0 . Such a measure is an essential tool for the study of equilibrium states. Assuming that the topological pressure of the boundary is small, that \log g has bounded distortion and an irreducibility condition, we build such a conformal measure.
Nonlocal elasticity and related variational principles
2001
Abstract The Eringen model of nonlocal elasticity is considered and its implications in solid mechanics studied. The model is refined by assuming an attenuation function depending on the `geodetical distance' between material particles, such that in the diffusion processes of the nonlocality effects certain obstacles as holes or cracks existing in the domain can be circumvented. A suitable thermodynamic framework with nonlocality is also envisaged as a firm basis of the model. The nonlocal elasticity boundary-value problem for infinitesimal displacements and quasi-static loads is addressed and the conditions for the solution uniqueness are established. Three variational principles, nonlocal…
Machine learning for rapid mapping of archaeological structures made of dry stones – Example of burial monuments from the Khirgisuur culture, Mongoli…
2020
11 pages; International audience; The present study proposes a workflow to extract from orthomosaics the enormous amount of dry stones used by past societies to construct funeral complexes in the Mongolian steppes. Several different machine learning algorithms for binary pixel classification (i.e. stone vs non-stone) were evaluated. Input features were extracted from high-resolution orthomosaics and digital elevation models (both derived from aerial imaging). Comparative analysis used two colour spaces (RGB and HSV), texture features (contrast, homogeneity and entropy raster maps), and the topographic position index, combined with nine supervised learning algorithms (nearest centroid, naive…
Effect of nitrogen limitation and nature of the feed upon Oenococcus oeni metabolism and extracellular protein production
2005
Aims: The aim of the study was to characterize the effect of various nitrogen sources on Oenococcus oeni growth, carbon source utilization, extracellular protease activity and extracellular proteins. More generally, the goal is to understand how nitrogen-based additives might act to enhance malolactic fermentation in wine. Methods and Results: Five yeast extracts were used. As the amino acid and nitrogen analyses revealed, they were similar in global amino acid composition, except for arginine level. Nevertheless the ratio of amino acids between free/bound, and low/high molecular weight fractions were highly different. One of the yeast extracts led to a significant protease activity in th…
Matrix Metalloproteases in Arterial Hypertension and their Trend after Antihypertensive Treatment
2017
<b><i>Background/Aims</i></b><b><i>:</i></b> Arterial hypertension is characterized by vascular remodelling, atherosclerosis and cardiovascular complications. Matrix metalloproteases (MPPs) are endopeptidases produced by all the cells present in the vascular wall and are involved in the regulation of the extracellular matrix protein turnover. MMPs contribute to blood vessel formation, remodelling, angiogenesis; whereas an altered expression or activity of MMPs or their tissue inhibitors (TIMPs) results correlated with the development and progression of cardiovascular complications. <b><i>Methods:</i></b> We examined the…
A Fast Imaging Technique Applied to 2D Electrical Resistivity Data
2014
A new technique is proposed to process 2D apparent resistivity datasets, in order to obtain a fast and contrasted resistivity image, useful for a rapid data check in field or as a starting model to constrain the inversion procedure. In the past some modifications to the back-projection algorithm, as well as the use of filtering techniques for the sensitivity matrix were proposed. An implementation of this technique is proposed here, considering a two-step approach. Initially a damped least squares solution is obtained after a full matrix inversion of the linearized geoelectrical problem. Furthermore, on the basis of the results, a subsequent filtering algorithm is applied to the Jacobian ma…
Delay-Probability-Distribution-Dependent FIR Filtering Design with Envelope Constraints
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/930927 Open Access This paper studies the problem of H∞ finite-impulse response (FIR) filtering design of time-delay system. The time-delay considered here is time-varying meanwhile with a certain stochastic characteristic, and the probability of delay distribution is assumed to be known. Furthermore, the requirement of pulse-shape is also considered in filter design. Employing the information about the size and probability distribution of delay, a delay-probability-distribution-dependent criterion is proposed for the filtering error syst…
Pose classification using support vector machines
2000
In this work a software architecture is presented for the automatic recognition of human arm poses. Our research has been carried on in the robotics framework. A mobile robot that has to find its path to the goal in a partially structured environment can be trained by a human operator to follow particular routes in order to perform its task quickly. The system is able to recognize and classify some different poses of the operator's arms as direction commands like "turn-left", "turn-right", "go-straight", and so on. A binary image of the operator silhouette is obtained from the gray-level input. Next, a slice centered on the silhouette itself is processed in order to compute the eigenvalues …
Global exponential stability of delayed Markovian jump fuzzy cellular neural networks with generally incomplete transition probability
2014
The problem of global exponential stability in mean square of delayed Markovian jump fuzzy cellular neural networks (DMJFCNNs) with generally uncertain transition rates (GUTRs) is investigated in this paper. In this GUTR neural network model, each transition rate can be completely unknown or only its estimate value is known. This new uncertain model is more general than the existing ones. By constructing suitable Lyapunov functionals, several sufficient conditions on the exponential stability in mean square of its equilibrium solution are derived in terms of linear matrix inequalities (LMIs). Finally, a numerical example is presented to illustrate the effectiveness and efficiency of our res…
Ultrastructural aspects of naturally occurring wound in the tunic of two ascidians: Ciona intestinalis and Styela plicata (Tunicata).
2015
Efficient wound healing is essential for all animals from insects to mammals. Ciona intestinalis and Styela plicata are solitary ascidians belonging to urochordates, a subphylum that occupies a key phylogenetic position as it includes the closest relative to vertebrates. Urochordate first physical barrier against invaders is the tunic, an extracellular matrix that is constantly exposed to all kinds of insults. Thus, when damage occurs, an innate immune response is triggered to eliminate impaired tissue and potentially pathogenic microbes, and restore tissue functionality. Ultrastructural aspects of the tunic in the wound healing process of two ascidians are described. In the injured areas, …