ANALYSE LES PERFORMANCES D’UN SYSTÈME DS-OCDMA EN UTILISANT LES CODES OPTIQUE ORTHOGONAUX (OOC)

In a DS-OCDMA system, the MAI is one of the major limitations due to the unipolarity of the codes used. To mitigate the MAI, several techniques are developed for receptions eliminate the contribution of unwanted users. In this work, we studied the characteristics of correlations OOC codes, and we presented three structures of receptors that are well placed to estimate the information bits. For this, we have developed the theoretical BER expressions error probability

Analyse Des réseaux De Bragg Superposés Pour l’encodage OCDMA. Utilisation Des Codes à Séquences premières

Cet article présente une nouvelle méthode de codage fréquentielle pour le CDMA optique à base de réseaux de Bragg superposés travaillant en réflexion. Des codes à séquences premières PS non cohérent, générées et décodées de manière « tout optique» par un composant spécifique. Le composant consiste en une succession de réseaux de Bragg inscrits sur une fibre optique à différentes longueurs d’onde et à des positions bien définis sur la fibre prédéfinie. L’ordre, ainsi que le choix des longueurs d’onde de ces réseaux de Bragg déterminent le code. La méthode des matrices de transfert a été retenue pour étudier et modéliser un réseau unique ou des réseaux superposés

EFFECT OF THE BIT RATE ON THE PULSES OF THE LASER DIODES

<p class="Default">The qualities required for Laser Diodes are their spatial and temporal coherence, and their performance in terms modulation.</p><p class="Default">This paper presents the effect data rate of optical pulses delivered by diode laser using software COMSIS.</p><p class="Default">Two types of modulation have been considered: direct modulation and external modulation. </p

Appears in Proceedings of the Sixteenth International Machine Learning Conference,

In natural language acquisition, it is di#- cult to gather the annotated data needed for supervised learning; however, unannotated data is fairly plentiful. Active learning methods attempt to select for annotation and training only the most informative examples, and therefore are potentially very useful in natural language applications. However, existing results for active learning have only considered standard classification tasks

Pachydermodactyly of a single finger

Pachydermodactyly is a non-inflammatory swelling which involves the dorsal and lateral surfaces of the fingers, at the level of proximal phalanges and interphalangeal joints. In the majority of cases 3 fingers are affected (only 3 cases of pachydermodactyly localized to a single finger have been described). The disorder is much more common in males (only 4 women have been reported). We present a clinical, histopathological and ultrastructural study of a woman with pachydermodactyly localized exclusively to one finger

An assessment of population size and demographic drivers of the Bearded Vulture using integrated population models

Conventional approaches for the assessment of population abundance or trends are usually based on a single source of information, such as counts or changes in demographic parameters. However, these approaches usually neglect some of the information needed to properly understand the population as a whole, such as assessments of the non‐breeding proportion of the population and the drivers of population change. The Bearded Vulture Gypaetus barbatus is a threatened species and its Pyrenean population (the largest in Europe) inhabits parts of Spain, Andorra, and France. We developed an Integrated Population Model (IPM) using data from a long‐term study (1987–2016) in the three countries, including capture–mark–recapture of 150 marked individuals, to assess population size and age structure at the whole population scale, and obtain estimates of survival and breeding parameters of this population. The breeding population experienced a geometric mean population increase of 3.3% annually, falling to 2.3% during the last 10 yr. The adult proportion of the population increased with time, from 61% to 73%. There were 365 (95% Bayesian credible interval [BCI]: 354–373) adult breeding birds in 2016, representing 49% of the adult population and 36% of the total population (estimated at 1,026 individuals, 95% BCI: 937–1,119). The large number of non‐breeding adults probably led to higher mean age of first reproduction than previously estimated, and to an estimated 30–35% of territories occupied by polyandrous trios. Population growth rate was positively and strongly correlated with adult survival, which had a much greater effect on population growth than productivity. The effects of subadult and juvenile survival on population growth were weaker. We found strong evidence for a density‐dependent decrease in juvenile survival, productivity and adult survival, leading to reduced population growth with increased population size. Our approach allowed us to identify important conservation issues related to the management of supplementary feeding sites and geographic expansion of this population. Our study supports the use of IPMs as a tool to understand long‐lived species, allowing simultaneous estimates of the non‐breeding size of the population (which is critical for understanding population functioning), better estimates of population parameters, and assessment of demographic drivers.This study was supported by projects CGL2015‐66966‐C2‐1‐R2 from Ministerio de Economía y Competitividad and RTI2018‐099609‐B‐C22 from Ministerio de Ciencia Innovación y Universidades.Peer reviewe