Search results for " pattern"
showing 10 items of 2245 documents
The Effect of Predator Population Dynamics on Batesian Mimicry Complexes.
2022
Understanding Batesian mimicry is a classic problem in evolutionary biology. In Batesian mimicry, a defended species (the model) is mimicked by an undefended species (the mimic). Prior theories have emphasized the role of predator behavior and learning as well as evolution in model-mimic complexes but have not examined the role of population dynamics in potentially governing the relative abundances and even persistence of model-mimic systems. Here, we examined the effect of the population dynamics of predators and alternative prey on the prevalence of warning-signaling prey composed of models and mimics. Using optimal foraging theory and signal detection theory, we found that the inclusion …
Diversity in warning coloration: selective paradox or the norm?
2019
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: …
Vegetation Patterns in the Hyperbolic Klausmeier Model with Secondary Seed Dispersal
2023
This work focuses on the dynamics of vegetation stripes in sloped semi-arid environments in the presence of secondary seed dispersal and inertial effects. To this aim, a hyperbolic generalization of the Klausmeier model that encloses the advective downhill transport of plant biomass is taken into account. Analytical investigations were performed to deduce the wave and Turing instability loci at which oscillatory and stationary vegetation patterns arise, respectively. Additional information on the possibility of predicting a null-migrating behavior was extracted with suitable approximations of the dispersion relation. Numerical simulations were also carried out to corroborate theoretical pre…
Identifying the Sales Patterns of Online Stores with Time Series Clustering
2018
Electronic commerce, especially in the business-to-consumer (B2C) context, has for years been a popular research topic in information systems (IS). However, the prior research on the topic has traditionally been dominated by the consumer focus instead of the business focus of online stores. For example, whereas various segmentations exist for online consumers based on their purchase behaviour, no such segmentations have been developed for online stores based on their sales patterns. In this study, our objective is to address this gap in prior research by identifying the most typical sales patterns of online stores operating in the B2C context. By using self-organising maps (SOM) to analyse …
Identifying the Sales Patterns of Online Stores with Self-Organising Maps on Time Series Data
2018
Electronic commerce, especially in the business-to-consumer (B2C) context, has for years been a popular research topic in information systems (IS). However, the prior research on the topic has traditionally been dominated by the consumer focus instead of the business focus of online stores. For example, whereas various segmentations exist for online consumers based on their purchase behaviour, no such segmentations have been developed for online stores based on their sales patterns. In this study, our objective is to address this gap in prior research by identifying the most typical sales patterns of online stores operating in the B2C context. By using self-organising maps (SOM) to analyse …
The ALICE experiment at the CERN LHC
2008
Journal of Instrumentation 3(08), S08002 (2008). doi:10.1088/1748-0221/3/08/S08002
Extraction d'un graphe de navigabilité à partir d'un nuage de points 3D enrichis
2017
International audience; Ce travail se place dans le cadre général du projet ANR pLaTINUM lié à la navigation autonome et plus parti-culièrement à la génération de cartes pour la navigation basée perception. Il consiste à développer une nouvelle méthode pour résumer une carte 3D (un nuage dense de points 3D) et extraire un graphe de navigabilité facilitant l'utilisation de cette carte par des systèmes de navigation à ressources matérielles limitées (smart-phones, voitures, robots.. .). Cette méthode vise à ex-traire les régions les plus saillantes de l'environnement étudié afin de construire une carte récapitulative. Ce processus de résumé de carte basé sur la vision est appliqué d'une façon…
Lidar detection of carbon dioxide in volcanic plumes
2015
Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high s…
Longitudinal Patterns of Ethical Organisational Culture as a Context for Leaders’ Well-Being: Cumulative Effects Over 6 Years
2021
AbstractThe aim of this longitudinal study was to investigate the temporal dynamics of ethical organisational culture and how it associates with well-being at work when potential changes in ethical culture are measured over an extended period of 6 years. We used a person-centred study design, which allowed us to detect both typical and atypical patterns of ethical culture stability as well as change among a sample of leaders. Based on latent profile analysis and hierarchical linear modelling we found longitudinal, concurrent relations and cumulative gain and loss cycles between different ethical culture patterns and leaders’ well-being. Leaders in the strongest ethical culture pattern exper…
Knowledge organization for modelling workflows in Taverna environment
2014
Today Workflow Management Systems (WFMS), like Taverna and Kepler, have a very important place in the everyday work of the scientist. These tools support the access to computational resources and act as interface for building complex data processing chains. The next step is to support decisions of the researcher on autonomously developing workflow parts guided by requirements of the scientist while she/he is working on the high-level goal of the experiment. To this aim, it is necessary an ontology to store the knowledge related to the experiments and tools used, and to make this knowledge available not only to the scientist, but also to a suitable artificial intelligent system. In this pape…