Search results for "Matching"
showing 9 items of 509 documents
Camouflage accuracy in Sahara-Sahel desert rodents
2020
1.Camouflage helps animals to hide from predators and is therefore key to survival. Although widespread convergence of animal phenotypes to their natural environment is well established, there is a lack of knowledge about how species compromise camouflage accuracy across different background types in their habitat. 2.Here we tested how background matching has responded to top‐down selection by avian and mammalian predators using Sahara‐Sahel desert rodents in North Africa. 3.We show that the fur coloration of several species has become an accurate match to different types of desert habitats. This is supported by a correlation analysis of colour and pattern metrics, investigation of animal‐t…
Improved camouflage through ontogenetic colour change confers reduced detection risk in shore crabs
2019
Abstract Animals from many taxa, from snakes and crabs to caterpillars and lobsters, change appearance with age, but the reasons why this occurs are rarely tested.We show the importance that ontogenetic changes in coloration have on the camouflage of the green shore crabs (Carcinus maenas), known for their remarkable phenotypic variation and plasticity in colour and pattern.In controlled conditions, we reared juvenile crabs of two shades, pale or dark, on two background types simulating different habitats for 10 weeks.In contrast to expectations for reversible colour change, crabs did not tune their background match to specific microhabitats, but instead, and regardless of treatment, all de…
The Eurasian Treecreeper (Certhia familiaris) has an effective camouflage against mammalian but not avian vision in boreal forests
2022
A well-known example of visual camouflage in birds is the plumage coloration of the Eurasian Treecreeper Certhia familiaris, yet this species’ camouflage has never been objectively quantified. Here, we quantify treecreeper camouflage in its boreal forest habitat, test whether treecreepers better match tree backgrounds at nest site, territory or habitat spatial scales, and explore which common tree species provide the best background match. Using photographic data of the birds and forested backgrounds, we test their background match using human, ferret and avian vision modelling. We found that a treecreeper’s wing and mantle provided closest background matching, whereas the wing stripe and t…
Context-aware data caching for 5G heterogeneous small cells networks
2016
In this work, we investigate the problem of context-aware data caching in the heterogeneous small cell networks (HSCNs) to provide satisfactory to the end-users in reducing the service latency. In particular, we explore the storage capability of base stations (BSs) in HSCNs and propose a data caching model consists of edge caching elements (CAEs), small cell base stations (SBSs), and macro cell BS (MBS). Then, we concentrate on how to efficiently match the data contents to the different cache entities in order to minimize the overall system service latency. We model it as a distributed college admission (CA) stable matching problem and tackle this issue by utilizing contextual information t…
Influence of the learning environment on the representational strategies of middle school music students: an intervention-based study
2015
The purpose of this study was to examine the effects of a hypermedia learning environment on middle school students' meta-representational competence (MRC) in the domain of music. Particularly, we aimed at determining whether an educational intervention influenced the accuracy with which middle school students matched sounds (sonic fragments) to symbols (graphic representations). The students were randomly allocated to the experimental condition. An intervention was set up so that the experimental group students (E) were provided with scaffolding aimed at enhancing their use of constructive resources to generate representations and their critical capabilities to judge them. On the other han…
Engine/Transmission Matching
2014
This chapter deals with the forecasting of vehicle performance on the road, according to the installed engine. It begins with Section 1, which shows the calculation of the resistance to motion, that is, the forces that the vehicle must overcome to advance on flat roads and uphill. The calculation excludes accidental resistance in curves because it is not essential for predicting the behavior of the vehicle on the road. Section 2 begins with the power characteristic, the forecast by traction–speed and power–speed diagrams, calculation of gear ratios, and then passing to the limits to the estimated acceleration, feature consumption, and distance. This chapter concludes with a section on the d…
International Assessment Surveys of Educational Achievement in Developing Countries : Why Education Economists Should Care
2015
International audience; This paper reviews the most known international assessment studies that are conducted in the context of poor countries and highlights the lack of empirical evidence on the degree to which the contents of the tests really match countries' curricula. To illustrate, the paper evaluates the sensitivity of an international testing instrument by comparing the responses of students in two consecutive grades on the same battery of tests. Using propensity score matching to control for student and teacher characteristics, the results show that the tests are not grade sensitive, which raises the question of the validity of many empirical works that are based on similar instrume…
Vārdu krājumu novērtējums ar dažādu testēšanu paņēmienu izmantošanu
2016
Darbā tika pētītas vārdu krājuma testēšanas paņēmienu priekšrocības un trūkumi un visefektīvākais un drošākais paņēmiens vārdu krājuma pārbaudei mācību apstākļos. Pētījuma rezultāti spēj veicināt izvēli par labu konkrētam testēšanas paņēmienam, saskaņā ar novērtēšanas veidu un mērķi, tēmu, mērķauditoriju un vidi. Darba teorētiskā daļa ir balstīta uz Arthur Hughes (2003), Scott Thornbury (2002), John Read (2000) un Penny Ur (1999) teorijas. Gadījuma metodes ietvaros tika vadīta mācību nodarbība, pēc kuras studentu zināšanas tika novērtētas ar autores izstrādāto testa palīdzību. Kvantitatīva analīze tika pielietota testa rezultātu noteikšanā un uzticamības mērīšanā, turklāt kvalitatīva analīz…
Webcam based display calibration
2012
International audience; We present an automatic method for measuring the tone response curve of display devices based on visual methods, where the eye is replaced by an end-user, uncalibrated camera, such as a webcam. Our approach compares a series of halftoned patches of known covering ratio with a continuous series of tone patches for each ratio. Both patches are shot by a camera that is used as a virtual eye to evaluate the luminance difference. By an iterative process, the continuous tone value is adjusted while compared with the perceived level of the halftoned patch. When the camera does not see any difference between the patches or a minimal difference, the luminance level of the con…