Extrait de : Narrative of a five years'expedition against the revolted negroes of Surinam in Guiana, on the wild coast of South America from the year 1772 to 1777, elucidating the history of that country and describing its productions... with an account of the Indians of Guiana and negroes of Guinea... Tome 2 (p. 10)

Droits : Domaine public
Permalien : http://www.manioc.org/images/SCH132430025i1
SCH132430025i1

Éditeur(s) : HAL CCSD
Résumé : International audience
More and more animal species are endangered. In order to study and protect them, several measures have been taken, which now seem to show their limit. This work focuses on the counting process, a key issue for any project that aims to protect animals. Indeed, this paper proposes an algorithm for automatic counting of singing birds in their habitat by using wireless sensors fitted with microphone. Sensors are used to record audio samples of bird songs. These samples are used to extract some kinds of song fingerprint that are thereafter used to recognize the bird species, through a classification process. Afterwards, by analyzing data which have been collected by a central base, the network structure derived from detection fields of sensors, allows our algorithm to propose an estimate of singing birds in the habitat. This paper details the counting algorithm which uses graph theory and audio inputs comparison. Finally, we demonstrate our scheme efficiency through experimentations.
Local Computer Networks (LCN)
Clearwater, United States

hal-00786165
https://hal.archives-ouvertes.fr/hal-00786165
DOI : 10.1109/LCNW.2012.6424060

Éditeur(s) : Archives de la Martinique
Résumé : Raspoot, agé de 28 ans, né à Menpouur, ancien Jemmedar au service de Masamy, Rajha de Kourough, dans la guerre contre les Hindous
15Fi57

Droits : Reproduction soumise à autorisation des Archives de la Martinique
http://www.patrimoines-martinique.org/ark:/35569/a011470672738TidXIY

Éditeur(s) : HAL CCSD Royal Society, The
Résumé : Plant leaf litter generally decomposes faster as a group of different species than when individual species decompose alone, but underlyingmechanisms of these diversity effects remain poorly understood. Because resource C : N: P stoichiometry (i.e. the ratios of these key elements) exhibits strong control on consumers, we supposed that stoichiometric dissimilarity of litter mixtures (i.e. the divergence in C : N: P ratios among species) improves resource complementarity to decomposers leading to faster mixture decomposition. We tested this hypothesis with: (i) a wide range of leaf litter mixtures of neotropical tree species varying in C : N: P dissimilarity, and (ii) a nutrient addition experiment (C, N and P) to create stoichiometric similarity. Litter mixtures decomposed in the field using two different types of litterbags allowing or preventing access to soil fauna. Litter mixture mass loss was higher than expected from species decomposing singly, especially in presence of soil fauna. With fauna, synergistic litter mixture effects increased with increasing stoichiometric dissimilarity of litter mixtures and this positive relationship disappeared with fertilizer addition. Our results indicate that litter stoichiometric dissimilarity drives mixture effects via the nutritional requirements of soil fauna. Incorporating ecological stoichiometry in biodiversity research allows refinement of the underlying mechanisms of how changing biodiversity affects ecosystem functioning.
ISSN: 0962-8452

hal-01204222
https://hal.archives-ouvertes.fr/hal-01204222
DOI : 10.1098/rspb.2014.1682
PRODINRA : 289918

Éditeur(s) : HAL CCSD
Résumé : International audience
A key issue for any project that aims to study endangered animals is the counting process. In this work, we propose an algorithm for automatic counting of singing birds in their habitat by using wireless sensors fitted with microphone. Sensors are used to record audio samples of bird songs and samples are analyzed to extract fingerprints that permit to recognize bird species. This paper details the counting algorithm that uses graph theory and audio inputs comparison. Finally, we demonstrate our scheme efficiency through experimentations.
International Symposium on a World of Wireless, Mobile and Multimedia Networks
Lucca, Italy

hal-00618563
https://hal.archives-ouvertes.fr/hal-00618563
DOI : 10.1109/WoWMoM.2011.5986215

Éditeur(s) : HAL CCSD ACM
Résumé : International audience
This study presents two algorithms that count birds with wireless sensors equipped with microphones. Audio inputs are parametrized to get some kind of fingerprints which are used to recognize the song of the birds in a classification process. Afterward, counting algorithms derive an estimate of the number of singing birds in the habitat. Unlike traditional approaches which leverage the audio waveform to get the location of the targets, we use a trilateration technique on graphs derived from the detection of the birds. These graphs exhibit nice properties which enable the finding of the estimate in polynomial time. Further, experiments are conducted and confirmm the efficiency of our counting algorithms even in the presence of noise.
Proceedings of the 6th ACM symposium on Performance evaluation of wireless ad hoc, sensor, and ubiquitous networks
New York, United States

hal-00602263
https://hal.archives-ouvertes.fr/hal-00602263
DOI : 10.1145/1641876.1641891