Search results for " pattern"
showing 10 items of 2245 documents
Classification of SD-OCT Volumes with LBP: Application to DME Detection
2015
International audience; This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with Diabetic Macular Edema (DME) versus normal subjects. Our method is based on Local Binary Patterns (LBP) features to describe the texture of Optical Coherence Tomography (OCT) images and we compare different LBP features extraction approaches to compute a single signature for the whole OCT volume. Experimental results with two datasets of respectively 32 and 30 OCT volumes show that regardless of using low or high level representations, features derived from LBP texture have highly discriminative power. Moreover, the experimen…
Classification of SD-OCT Volumes Using Local Binary Patterns: Experimental Validation for DME Detection
2016
International audience; This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with Diabetic Macular Edema (DME) versus normal subjects. Optical Coherence Tomography (OCT) has been a valuable diagnostic tool for DME, which is among the most common causes of irreversible vision loss in individuals with diabetes. Here, a classification framework with five distinctive steps is proposed and we present an extensive study of each step. Our method considers combination of various pre-processings in conjunction with Local Binary Patterns (LBP) features and different mapping strategies. Using linear and non-linear cl…
Spatio-temporal Contrast Sensitivity in the Cardinal Directions of the Colour Space. A Review
2010
AbstractWe review the psychophysics of the spatio-temporal contrast sensitivity in the cardinal directions of the colour space and their correlation with those neural characteristics of the visual system that limit the ability to perform contrast detection or pattern-resolution tasks. We focus our attention particularly on the influence of luminance level, spatial extent and spatial location of the stimuli - factors that determine the characteristics of the physiological mechanisms underlying detection. Optical factors do obviously play a role, but we will refer to them only briefly. Contrast sensitivity measurements are often used in clinical practice as a method to detect, at their early …
Embodied Meter Revisited : Entrainment, Musical Content, and Genre in Music-Induced Movement
2022
Previous research has shown that humans tend to embody musical meter at multiple beat levels during spontaneous dance. This work that been based on identifying typical periodic movement patterns, or eigenmovements, and has relied on time-domain analyses. The current study: 1) presents a novel method of using time-frequency analysis in conjunction with group-level tensor decomposition; 2) compares its results to time-domain analysis, and 3) investigates how the amplitude of eigenmovements depends on musical content and genre. Data comprised three-dimensional motion capture of 72 participants’ spontaneous dance movements to 16 stimuli including eight different genres. Each trial was subjected…
Reply to comment by Ngako and Njonfang on “The Adamawa-Yade domain, a piece of Archaean crust in the Neoproterozoic Central African Orogenic belt (Ba…
2018
Abstract V. Ngako and E. Njonfang addressed in their comment an interesting and debated issue about the collision geodynamics of the Pan-African Central African Orogenic Belt (CAOB) in Cameroon. However, the reason for this comment is still not clear to us since it mainly deals with issues far away from the scope of our study, namely, the pre-collisional set up of the belt. The comment raises two main points – the reworking process during plate collision and the Pan-African strain pattern – not discussed in our paper for the simple reason that it was not our goal and because our data set does not even allow such discussion. Having said that, the comment gives us the opportunity to clarify o…
Age and spatial structure of natural Pinus sylvestris stands in Latvia
2005
Abstract The age and spatial structure of six natural old growth Pinus sylvestris stands in Latvia were investigated, to attempt to identify retrospectively the past features of development. In each stand, one or two plots of size 200–900 m2 were established. Tree locations were mapped, stem diameter was measured, and tree age was determined from cores or by counting branch whorls. Tree distribution was assessed by Ripley's K function. A clumped spatial pattern was shown for P. sylvestris younger than 100 years. The temporal patterns of establishment could be partly linked to favourable climatic periods. The major disturbance affecting pine stands along the coast was windblown sand, which p…
Diel variability in counts of reef fishes and its implications for monitoring
2006
Studies of reef fish assemblages in space rarely consider the effects of temporal variability on spatial comparisons, and when they do, usually examine timescales of months to years. The nature of fish monitoring surveys is such that particular locations may be surveyed at one time of day, and surveys designed to establish the degree of spatial variability in assemblages may be confounded if the order of sampling within treatments is not randomised with respect to time of day. In this study, we tested the degree of temporal variability in temperate reef fish counts at the same sites in New Zealand and Italy, within and between days. Repeated counts separated by months returned quite differe…
Habitat type and island identity as drivers of community assembly in an archipelago
2020
Aim: Ecoinformatics offer new opportunity to test islands as biogeographic and eco- logical models. In this paper we predicted three hypotheses: (1) plot-based data issu- ing from vegetation surveys can be used to predict Island Species-Area Relationships (ISARs) or island similarity; (2) the habitat area is an independent predictor of species richness patterns within island; (3) species richness and composition are more de- pendent on habitat type than island identity in land-bridge islands. Area: Tuscan Archipelago, Italy. Methods: We assembled a database of all the vegetation plots available for the archi- pelago. For the first hypothesis we calculated ISARs, using Arrhenius model, and B…
Mitigation of urban flooding: A simplified approach for distributed stormwater management practices selection and planning
2005
The urbanization process and the hydraulic insufficiency of drainage systems are two of the most common causes of urban flooding. In some technical regulations, distributed stormwater management practices (DSMPs) are regarded as a solution for urban flooding problems. They can prevent the formation of runoff, dispose of it locally, or dampen its peak before it reaches the drainage system. Due to their diffuse localization and the wide number of available solutions, the evaluation of their efficiency in terms of flood reduction is very difficult. The methodology proposed in the present paper relies on the concept that the mitigation effects of DSMPs can be expressed as a function of the chan…
Early warning thresholds for partially saturated slopes in volcanic ashes
2013
Rainfall-induced landslides in steep soil slopes of volcanic origin are a major threat to human lives and infrastructure. In the context of constructing early warning systems in regions where extensive data on landslide occurrences and associated rainfall are inexistent, physically-based tools offer the possibility to establish thresholds for measurable field quantities. In this paper, a combined finite element infinite slope model is presented to study the transient hydraulic response of volcanic ash slopes to a series of rainfall events and to estimate seasonal safety factors. Furthermore, analytical considerations of partially saturated infinite slopes are made to define capillary stress…