723 research outputs found
Model-based verification of a security protocol for conditional access to services
peer reviewedWe use the formal language LOTOS to specify and verify the robustness of the Equicrypt protocol under design in the European OKAPI project for conditional access to multimedia services. We state some desired security properties and formalize them. We describe a generic intruder process and its modelling, and show that some properties are falsified in the presence of this intruder. The diagnostic sequences can be used almost directly to exhibit the scenarios of possible attacks on the protocol. Finally, we propose an improvement of the protocol which satisfies our properties
QoS specification of ODP binding objects
We present a QoS oriented notation suitable for the ODP framework. In particular, we focus on a computational view of objects: we consider systems described as configurations of interacting objects and we deal with two types of communications: message passing and flows. In message passing, signals (from one object to another) are conveyed through the (implicit) underlying infrastructure. This form of interaction is suitable for client/server applications where no strong real time or ordering constraints are needed from the communication infrastructure. In contract, in a flow type of communication, signals are conveyed through third party (binding) objects that may be explicitly called for in order to ensure specific QoS requirements needed by specific applications. A building blocks approach for the formal specification of binding objects in the ODP computational model is presented. The formal notation that is used is based on LOTOS extended with two features - real time and gate passing. These features are among the extensions that are currently studied in the ISO standardisation Formal Description Techniques group. We apply our building blocks approach to the specification of a multicast, multimedia binding object
Analyse du cycle de vie de nouveaux mortiers contenant des argiles calcinées comme additions : le projet CO2REDRES
peer reviewedDepuis longtemps, le ciment Portland a prouvé son utilité dans les constructions conventionnelles en béton. Cependant, malgré ses nombreuses qualités, ce matériau est également responsable d’importantes émissions de gaz à effet de serre et d'une consommation significative d’énergie. Ces inconvénients sont liés à la production du clinker, constituant majeur du ciment. Pendant longtemps, le laitier de haut fourneau et les cendres volantes ont été utilisés comme substituants partiels du clinker afin d'en diminuer l'utilisation, et réduire ainsi les impacts environnementaux du ciment. Ces matériaux secondaires se raréfient dans plusieurs zones géographiques, y compris dans la Grande Région. C’est dans ce contexte que le projet CO2REDRES prend place, ayant pour but de démontrer la faisabilité de la production d’additions minérales ayant des propriétés hydrauliques et/ou pouzzolaniques à partir de ressources secondaires (déchets ou sous-produits industriels). La présente étude expose l’analyse du cycle de vie de cette nouvelle production d’additions minérales, afin d'en caractériser les impacts environnementaux et de démontrer leurs avantages potentiels en substitution.CO2REDRES11. Sustainable cities and communities13. Climate action9. Industry, innovation and infrastructur
ToRQuEMaDA: tool for retrieving queried Eubacteria, metadata and dereplicating assemblies
peer reviewedTQMD is a tool for high-performance computing clusters which downloads, stores and produces lists of dereplicated prokaryotic genomes. It has been developed to counter the ever-growing number of prokaryotic genomes and their uneven taxonomic distribution. It is based on word-based alignment-free methods (k-mers), an iterative single-linkage approach and a divide-and-conquer strategy to remain both efficient and scalable. We studied the performance of TQMD by verifying the influence of its parameters and heuristics on the clustering outcome. We further compared TQMD to two other dereplication tools (dRep and Assembly-Dereplicator). Our results showed that TQMD is primarily optimized to dereplicate at higher taxonomic levels (phylum/class), as opposed to the other dereplication tools, but also works at lower taxonomic levels (species/strain) like the other dereplication tools. TQMD is available from source and as a Singularity container at [https://bitbucket.org/phylogeno/tqmd ]
Determination of Moisture Diffusivity During Drying of Mortar Cement: Experimental and Modeling Study
The aim of this study is the experimental characterization of the behaviour of a mortar during convective drying. We focalise on mortar that has a rate water-cement of 0.5. The drying tests are developed in a micro-convective dryer that can use samples weighing from 0 to 8g. The advantage of these experiments is to reproduce the natural conditions that can be found during the treatment of the mortar-atmosphere problems. The response of the drying curve or the drying kinetic depends on the applied drying conditions. So, the temperature of the air varies from 60°C to 130°C, the velocity of the air is changed from 2 m.s-1 to 5 m. s-1and the relative humidity is kept less than 1.7%. The comparison between the experimental results and the proposed analytical solutions of the equation of diffusion represented by Fick’s law, applied for a finite shape, allows determination of the values of the diffusion coefficient. It has a value of 1.71×10-10 m2.s-1 at 60°C, 13.69×10-10 m2.s-1 at 90°C and 16.27×10-10 m2.s-1 at 130°C. Calculation of the activation energy and the D0 constant are also possible
Phylogenomic Analyses of Snodgrassella Isolates from Honeybees and Bumblebees Reveal Taxonomic and Functional Diversity.
peer reviewedSnodgrassella is a genus of Betaproteobacteria that lives in the gut of honeybees (Apis spp.) and bumblebees (Bombus spp). It is part of a conserved microbiome that is composed of a few core phylotypes and is essential for bee health and metabolism. Phylogenomic analyses using whole-genome sequences of 75 Snodgrassella strains from 4 species of honeybees and 14 species of bumblebees showed that these strains formed a monophyletic lineage within the Neisseriaceae family, that Snodgrassella isolates from Asian honeybees diverged early from the other species in their evolution, that isolates from honeybees and bumblebees were well separated, and that this genus consists of at least seven species. We propose to formally name two new Snodgrassella species that were isolated from bumblebees: i.e., Snodgrassella gandavensis sp. nov. and Snodgrassella communis sp. nov. Possible evolutionary scenarios for 107 species- or group-specific genes revealed very limited evidence for horizontal gene transfer. Functional analyses revealed the importance of small proteins, defense mechanisms, amino acid transport and metabolism, inorganic ion transport and metabolism and carbohydrate transport and metabolism among these 107 specific genes. IMPORTANCE The microbiome of honeybees (Apis spp.) and bumblebees (Bombus spp.) is highly conserved and represented by few phylotypes. This simplicity in taxon composition makes the bee's microbiome an emergent model organism for the study of gut microbial communities. Since the description of the Snodgrassella genus, which was isolated from the gut of honeybees and bumblebees in 2013, a single species (i.e., Snodgrassella alvi), has been named. Here, we demonstrate that this genus is actually composed of at least seven species, two of which (Snodgrassella gandavensis sp. nov. and Snodgrassella communis sp. nov.) are formally described and named in the present publication. We also report the presence of 107 genes specific to Snodgrassella species, showing notably the importance of small proteins and defense mechanisms in this genus
Optimizing vibration parameters of thick single-layer concrete pavements: results of the Belgian Monocrete project
peer reviewedThick single-layer concrete pavements are increasingly popular in Europe because they help tackle the increasing traffic loads on highways, airport taxiways, or industrial logistic platforms. They require less maintenance than other pavement materials, have a very long service life even under heavy loads, and can withstand static loads without permanent deformation. However, the environmental impact of such pavements is significant, due to the vast quantities of cement and inert materials required for each project. The MONOCRETE research project (March 2021-March 2024), funded by the Walloon GreenWin innovation cluster, brings together industrial partners (Eloy and Holcim) as well as research institutions (BRRC, CRIC-OCCN, and ULiège) with the aim of reducing this environmental impact by incorporating recycled concrete aggregates and an alternative, low-carbon cement. In addition to issues relating to concrete sustainability, the project studies the formulation and execution of thick concrete pavements. Indeed, a greater thickness will accentuate any compaction or vibration problem associated with a poor particle size distribution. The risk of bleeding or segregation is therefore increased. These issues are being studied through a combination of literature review, laboratory testing, and the execution of two test sections, implemented in fall 2022 and spring 2023. The purpose of this paper is to summarize the initial conclusions of this recent project on the vibration of thick concrete pavements.MonoCrete - Revêtement monocouche épais à base de liants alternatifs et de granulats recyclés11. Sustainable cities and communitie
Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan
This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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