Search results for "Pattern"
showing 10 items of 4203 documents
Time Unification on Local Binary Patterns Three Orthogonal Planes for Facial Expression Recognition
2019
International audience; Machine learning has known a tremendous growth within the last years, and lately, thanks to that, some computer vision algorithms started to access what is difficult or even impossible to perceive by the human eye. While deep learning based computer vision algorithms have made themselves more and more present in the recent years, more classical feature extraction methods, such as the ones based on Local Binary Patterns (LBP), still present a non negligible interest, especially when dealing with small datasets. Furthermore, this operator has proven to be quite useful for facial emotions and human gestures recognition in general. Micro-Expression (ME) classification is…
Pattern formation in hyperbolic reaction-transport systems and applications to dryland ecology
2023
Pattern formation and modulation is an active branch of mathematics, not only from the perspective of fundamental theory but also for its huge applications in many fields of physics, ecology, chemistry, biology, and other sciences. In this thesis, the occurrence of Turing and wave instabilities, giving rise to stationary and oscillatory patterns, respectively, is theoretically investigated by means of two-compartment reaction-transport hyperbolic systems. The goal is to elucidate the role of inertial times, which are introduced in hyperbolic models to account for the finite-time propagation of disturbances, in stationary and transient dynamics, in supercritical and subcritical regimes. In p…
Energy and speleogenesis: Key determinants of terrestrial species richness in caves
2017
Abstract The aim of this study was to unravel the relative role played by speleogenesis (i.e., the process in which a cave is formed), landscape‐scale variables, and geophysical factors in the determination of species richness in caves. Biological inventories from 21 caves located in the southeastern Iberian Peninsula along with partial least square (PLS) regression analysis were used to assess the relative importance of the different explanatory variables. The caves were grouped according to the similarity in their species composition; the effect that spatial distance could have on similarity was also studied using correlation between matrices. The energy and speleogenesis of caves account…
Restoration and Enhancement of Historical Stereo Photos
2021
Restoration of digital visual media acquired from repositories of historical photographic and cinematographic material is of key importance for the preservation, study and transmission of the legacy of past cultures to the coming generations. In this paper, a fully automatic approach to the digital restoration of historical stereo photographs is proposed, referred to as Stacked Median Restoration plus (SMR+). The approach exploits the content redundancy in stereo pairs for detecting and fixing scratches, dust, dirt spots and many other defects in the original images, as well as improving contrast and illumination. This is done by estimating the optical flow between the images, and using it …
Multi-modal Image Registration Using Fuzzy Kernel Regression
2009
This paper presents a study aimed to the realization of a novel multiresolution registration framework. The transformation function is computed iteratively as a composition of local deformations determined by the maximization of mutual information. At each iteration, local transformations are joint together using fuzzy kernel regression. This technique represents the core of the mothod and it's formally described from a probabilistic perspective. It avoids blocking artifacts and allows to keep the final deformation spatially congruent and smooth. Both qualitative and quantitative experimental results show that this approach is equally effective for registering datasets acquired from both si…
Can Individual Movement Characteristics Across Different Throwing Disciplines Be Identified in High-Performance Decathletes?
2020
Although the individuality of whole-body movements has been suspected for years, the scientific proof and systematic investigation that individuals possess unique movement patterns did not manifest until the introduction of the criteria of uniqueness and persistence from the field of forensic science. Applying the criteria of uniqueness and persistence to the individuality of motor learning processes requires complex strategies due to the problem of persistence in the learning processes. One approach is to examine the learning process of different movements. For this purpose, it is necessary to differentiate between two components of movement patterns: the individual-specific component and …
The grapevine LysM receptor-like kinase VvLYK5-1 mediates chitin-triggered immunity
2021
The establishment of defense reactions to protect plants against invading pathogens first requiresthe recognition of Microbe-Associated Molecular Patterns (MAMPs), detected by plasmamembrane-bound Pattern Recognition Receptors (PRRs). These MAMPs, also termed elicitors, areused in several biocontrol products that are gradually developing to reduce the use of chemicalpesticides in agriculture. Chitin, the main component of fungal cell walls, as well as its deacetylatedderivative, chitosan, are two chitooligosaccharides (COS) that can be found in some of theseproducts. Unfortunately, the mechanism allowing the perception of these molecules is still poorlyunderstood in Vitis vinifera, sometime…
Modelling the Impacts of Wildfire on Ash Thickness in a Short‐Term Period
2013
Ash can provide valuable soil protection. However, ash is also very mobile, and soil protection patterns can be quickly changed, favouring the protection of some areas and exposing others with implications for soil erosion. In this research, the effects of a high severity wildfire on ash thickness were studied, 1 and 15 days after the fire. For this evaluation, several interpolation methods were tested to identify the best spatial predictor of ash distribution. The results showed that 1 day after the fire, ash was thinner in high severity areas. Fifteen days after the fire, ash thickness decreased, and the spatial pattern changed. This implies that evaluation of fire severity based on ash t…
Semi-blind Source Extraction Methods: Application to the measurement of non-contact physiological signs
2018
Non-contact physiological measurements are highlydesirable in many biomedical fields such asdiagnosis of infants, geriartic patients, patients withextreme physical trauma, and fitness and well-being.Remote photoplethysmography is increasingly beingused for non-contact measurement of heart rate fromvideos which is one of the most common biomedicalproperty required for most medical diagnosis. Oneof the common techniques for performing remotephotoplethysmography involves using Blind SourceSeparation (BSS) methods to extract the cardiacsignal from video data.In this context, the objective of this thesis is todevelop different methods in the field of extractionand separation of sources by improv…