15,152 research outputs found
Simple identification tools in FishBase
Simple identification tools for fish species were included in the FishBase information system from its inception. Early tools made use of the relational model and characters like fin ray meristics. Soon pictures and drawings were added as a further help, similar to a field guide. Later came the computerization of existing dichotomous keys, again in combination with pictures and other information, and the ability to restrict possible species by country, area, or taxonomic group. Today, www.FishBase.org offers four different ways to identify species. This paper describes these tools with their advantages and disadvantages, and suggests various options for further
development. It explores the possibility of a holistic and integrated computeraided strategy
Vision-Based Road Detection in Automotive Systems: A Real-Time Expectation-Driven Approach
The main aim of this work is the development of a vision-based road detection
system fast enough to cope with the difficult real-time constraints imposed by
moving vehicle applications. The hardware platform, a special-purpose massively
parallel system, has been chosen to minimize system production and operational
costs. This paper presents a novel approach to expectation-driven low-level
image segmentation, which can be mapped naturally onto mesh-connected massively
parallel SIMD architectures capable of handling hierarchical data structures.
The input image is assumed to contain a distorted version of a given template;
a multiresolution stretching process is used to reshape the original template
in accordance with the acquired image content, minimizing a potential function.
The distorted template is the process output.Comment: See http://www.jair.org/ for any accompanying file
zCOSMOS â 10k-bright spectroscopic sample : The bimodality in the galaxy stellar mass function: exploring its evolution with redshift
We present the galaxy stellar mass function (GSMF) to redshift z â 1, based on the analysis of about 8500 galaxies with I < 22.5 (AB mag)
over 1.4 deg^2, which are part of the zCOSMOS-bright 10k spectroscopic sample. We investigate the total GSMF, as well as the contributions of
early- and late-type galaxies (ETGs and LTGs, respectively), defined by different criteria (broad-band spectral energy distribution, morphology,
spectral properties, or star formation activities). We unveil a galaxy bimodality in the global GSMF, whose shape is more accurately represented
by 2 Schechter functions, one linked to the ETG and the other to the LTG populations. For the global population, we confirm a mass-dependent
evolution (âmass-assembly downsizingâ), i.e., galaxy number density increases with cosmic time by a factor of two between z = 1 and z = 0 for
intermediate-to-low mass (log(M/M_â) ~ 10.5) galaxies but less than 15% for log(M/M_â) > 11.We find that the GSMF evolution at intermediate-to-
low values of M(log(M/M_â) < 10.6) is mostly explained by the growth in stellar mass driven by smoothly decreasing star formation activities,
despite the redder colours predicted in particular at low redshift. The low residual evolution is consistent, on average, with ~0.16 merger per
galaxy per Gyr (of which fewer than 0.1 are major), with a hint of a decrease with cosmic time but not a clear dependence on the mass. From
the analysis of different galaxy types, we find that ETGs, regardless of the classification method, increase in number density with cosmic time
more rapidly with decreasing M, i.e., follow a top-down building history, with a median âbuilding redshiftâ increasing with mass (z > 1 for
log(M/M_â) > 11), in contrast to hierarchical model predictions. For LTGs, we find that the number density of blue or spiral galaxies with
log(M/M_â) > 10 remains almost constant with cosmic time from z ~ 1. Instead, the most extreme population of star-forming galaxies (with
high specific star formation), at intermediate/high-mass, rapidly decreases in number density with cosmic time. Our data can be interpreted as
a combination of different effects. Firstly, we suggest a transformation, driven mainly by SFH, from blue, active, spiral galaxies of intermediate
mass to blue quiescent and subsequently (1â2 Gyr after) red, passive types of low specific star formation. We find an indication that the complete
morphological transformation, probably driven by dynamical processes, into red spheroidal galaxies, occurred on longer timescales or followed
after 1â2 Gyr. A continuous replacement of blue galaxies is expected to be accomplished by low-mass active spirals increasing their stellar
mass. We estimate the growth rate in number and mass density of the red galaxies at different redshifts and masses. The corresponding fraction
of blue galaxies that, at any given time, is transforming into red galaxies per Gyr, due to the quenching of their SFR, is on average ~25% for
log(M/M_â) < 11. We conclude that the build-up of galaxies and in particular of ETGs follows the same downsizing trend with mass (i.e. occurs
earlier for high-mass galaxies) as the formation of their stars and follows the converse of the trend predicted by current SAMs. In this scenario, we
expect there to be a negligible evolution of the galaxy baryonic mass function (GBMF) for the global population at all masses and a decrease with
cosmic time in the GBMF for the blue galaxy population at intermediate-high masses
Cued Speech Gesture Recognition: A First Prototype Based on Early Reduction
International audienceCued Speech is a specific linguistic code for hearing-impaired people. It is based on both lip reading and manual gestures. In the context of THIMP (Telephony for the Hearing-IMpaired Project), we work on automatic cued speech translation. In this paper, we only address the problem of automatic cued speech manual gesture recognition. Such a gesture recognition issue is really common from a theoretical point of view, but we approach it with respect to its particularities in order to derive an original method. This method is essentially built around a bioinspired method called early reduction. Prior to a complete analysis of each image of a sequence, the early reduction process automatically extracts a restricted number of key images which summarize the whole sequence. Only the key images are studied from a temporal point of view with lighter computation than the complete sequenc
Biometrics
Biometrics-Unique and Diverse Applications in Nature, Science, and Technology provides a unique sampling of the diverse ways in which biometrics is integrated into our lives and our technology. From time immemorial, we as humans have been intrigued by, perplexed by, and entertained by observing and analyzing ourselves and the natural world around us. Science and technology have evolved to a point where we can empirically record a measure of a biological or behavioral feature and use it for recognizing patterns, trends, and or discrete phenomena, such as individuals' and this is what biometrics is all about. Understanding some of the ways in which we use biometrics and for what specific purposes is what this book is all about
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