Search results for " Parallel"
showing 10 items of 224 documents
The Jurassic ammonite Coelocerus: an atypical example of dimorphic progenesis elucidated by cladistics
1994
Instances of convergence or parallelism among unrelated Lower Carixian ammonites are not uncommon. The case of polymorphitid-like ammonites is considered here, and the example of Coeloceras is investigated in detail. The small sexual dimorph (microconch) of Coeloceras pettos (Quensitedt) (Coeloceratidae), a progenetic species, provides a remarkable example of complex convergence with the microconch of Uptonia (Polymorphitidae). Homeomorphic morphology is here an amalgam of juvenile traits, of maturation-related transformations, and of completely new features bearing no obvious relation with either progenesis or maturation. A stratophenetic approach is hardly adequate for unravelling such an…
Ancestral Reconstruction and Investigations of Genomic Recombination on some Pentapetalae Chloroplasts
2019
Abstract In this article, we propose a semi-automated method to rebuild genome ancestors of chloroplasts by taking into account gene duplication. Two methods have been used in order to achieve this work: a naked eye investigation using homemade scripts, whose results are considered as a basis of knowledge, and a dynamic programming based approach similar to Needleman-Wunsch. The latter fundamentally uses the Gestalt pattern matching method of sequence matcher to evaluate the occurrences probability of each gene in the last common ancestor of two given genomes. The two approaches have been applied on chloroplastic genomes from Apiales, Asterales, and Fabids orders, the latter belonging to Pe…
A Hardware and Secure Pseudorandom Generator for Constrained Devices
2018
Hardware security for an Internet of Things or cyber physical system drives the need for ubiquitous cryptography to different sensing infrastructures in these fields. In particular, generating strong cryptographic keys on such resource-constrained device depends on a lightweight and cryptographically secure random number generator. In this research work, we have introduced a new hardware chaos-based pseudorandom number generator, which is mainly based on the deletion of an Hamilton cycle within the $N$ -cube (or on the vectorial negation), plus one single permutation. We have rigorously proven the chaotic behavior and cryptographically secure property of the whole proposal: the mid-term eff…
Why Cortices ? Neural Computation in the Vertebrate Visual System
1989
We propose three high level structural principles of neural networks in the vertebrate visual cortex and discuss some of their computational implications for early vision: a) Lamination, average axonal and dendritic domains, and intrinsic feedback determine the spatio-temporal interactions in cortical processing. Possible applications of the resulting filters include continuous motion perception and the direct measurement of high-level parameters of image flow, b) Retinotopic mapping is an emergent property of massively parallel connections. With a local intrinsic operation in the target area, mapping combines to a space-variant image processing system as would be useful in the analysis of …
Efficient distributed average consensus in wireless sensor networks
2020
International audience; Computing the distributed average consensus in Wireless Sensor Networks (WSNs) is investigated in this article. This problem, which is both natural and important, plays a significant role in various application fields such as mobile agents and fleet vehicle coordination, network synchronization, distributed voting and decision, load balancing of divisible loads in distributed computing network systems, and so on. By and large, the average consensus' objective is to have all nodes in the network converged to the average value of the initial nodes' measurements based only on local nodes' information states. In this paper, we introduce a fully distributed algorithm to a…
Many-body perturbation theory calculations using the yambo code
2019
Abstract yambo is an open source project aimed at studying excited state properties of condensed matter systems from first principles using many-body methods. As input, yambo requires ground state electronic structure data as computed by density functional theory codes such as Quantum ESPRESSO and Abinit. yambo’s capabilities include the calculation of linear response quantities (both independent-particle and including electron–hole interactions), quasi-particle corrections based on the GW formalism, optical absorption, and other spectroscopic quantities. Here we describe recent developments ranging from the inclusion of important but oft-neglected physical effects such as electron–phonon i…
Construction of Disjoint Virtual Backbones for Wireless Sensor Networks
2020
A wireless sensor network is a wireless network of sensors aimed at monitoring physical events. It has ingratiated itself into almost all areas of human endeavors. Data dissemination in these networks is quite challenging and is generally accomplished by flooding. But flooding introduces broadcast storm problem due from implosion and overlap. To overcome this, topology management can prescribe a virtual backbone network to which routing is confined. In this paper we propose an algorithm that constructs multiple disjoint virtual backbone networks, using only nodes' locations. The disjointedness makes routing more robust and the network exploitation energy efficient. Simulations show our algo…
Bayesian hierarchical models for analysing the spatial distribution of bioclimatic indices
2017
A methodological approach for modelling the spatial distribution of bioclimatic indices is proposed in this paper. The value of the bioclimatic index is modelled with a hierarchical Bayesian model that incorporates both structured and unstructured random effects. Selection of prior distributions is also discussed in order to better incorporate any possible prior knowledge about the parameters that could refer to the particular characteristics of bioclimatic indices. MCMC methods and distributed programming are used to obtain an approximation of the posterior distribution of the parameters and also the posterior predictive distribution of the indices. One main outcome of the proposal is the …
CRiSPy-CUDA: Computing Species Richness in 16S rRNA Pyrosequencing Datasets with CUDA
2011
Pyrosequencing technologies are frequently used for sequencing the 16S rRNA marker gene for metagenomic studies of microbial communities. Computing a pairwise genetic distance matrix from the produced reads is an important but highly time consuming task. In this paper, we present a parallelized tool (called CRiSPy) for scalable pairwise genetic distance matrix computation and clustering that is based on the processing pipeline of the popular ESPRIT software package. To achieve high computational efficiency, we have designed massively parallel CUDA algorithms for pairwise k-mer distance and pairwise genetic distance computation. We have also implemented a memory-efficient sparse matrix clust…