3,075 research outputs found
The Dynamic Phase Transition for Decoding Algorithms
The state-of-the-art error correcting codes are based on large random
constructions (random graphs, random permutations, ...) and are decoded by
linear-time iterative algorithms. Because of these features, they are
remarkable examples of diluted mean-field spin glasses, both from the static
and from the dynamic points of view. We analyze the behavior of decoding
algorithms using the mapping onto statistical-physics models. This allows to
understand the intrinsic (i.e. algorithm independent) features of this
behavior.Comment: 40 pages, 29 eps figure
AoI-based Multicast Routing over Voronoi Overlays with Minimal Overhead
The increasing pervasive and ubiquitous presence of devices at the edge of
the Internet is creating new scenarios for the emergence of novel services and
applications. This is particularly true for location- and context-aware
services. These services call for new decentralized, self-organizing
communication schemes that are able to face issues related to demanding
resource consumption constraints, while ensuring efficient locality-based
information dissemination and querying. Voronoi-based communication techniques
are among the most widely used solutions in this field. However, when used for
forwarding messages inside closed areas of the network (called Areas of
Interest, AoIs), these solutions generally require a significant overhead in
terms of redundant and/or unnecessary communications. This fact negatively
impacts both the devices' resource consumption levels, as well as the network
bandwidth usage. In order to eliminate all unnecessary communications, in this
paper we present the MABRAVO (Multicast Algorithm for Broadcast and Routing
over AoIs in Voronoi Overlays) protocol suite. MABRAVO allows to forward
information within an AoI in a Voronoi network using only local information,
reaching all the devices in the area, and using the lowest possible number of
messages, i.e., just one message for each node included in the AoI. The paper
presents the mathematical and algorithmic descriptions of MABRAVO, as well as
experimental findings of its performance, showing its ability to reduce
communication costs to the strictly minimum required.Comment: Submitted to: IEEE Access; CodeOcean: DOI:10.24433/CO.1722184.v1;
code: https://github.com/michelealbano/mabrav
AmI Systems as Agent-Based Mirror Worlds: Bridging Humans and Agents through Stigmergy
In this chapter we introduce a vision of agent-oriented AmI systems that is extended to integrate ideas inspired by MirrorWorlds as introduced by Gelernter at the beginning of the eighties. In this view, AmI systems are actually a digital world mirroring but also augmenting the physical world with capabilities, services and functionalities.We then discuss the value of stigmergy as background reference conceptual framework to define and understand interactions occurring between the physical environments and its digital agent-based extension. The digital world augments the physical world so that traces left by humans acting in the physical world are represented in the digital one in order to be perceived by software agents living there and, viceversa, actions taken by software agents in the mirror can have an effect on the connected physical counterpart
Study of the chemical and nutritional characteristics of commercial dog foods used as elimination diet for the diagnosis of canine food allergy
"Hypoallergenic" pet foods are commercial dietary products for dogs and cats used as elimination diets for the diagnosis of adverse food reactions. Aim of this study was to compare chemical and nutritional characteristics of this kind of dog foods with regular maintenance diets. Twenty-nine dry pet foods (pellets) were collected and divided into classes on the basis of the type (H: hypoallergenic; R: regular), source of fat (with or without fish oil) and source of protein (with or without fish protein) used in their composition. Labels of the H pet foods identified 8 products (44%) with one protein in their formula, suggesting that only few commercial manufacturers concern about the number of protein sources included in their products. Samples of the two groups showed different chemical profiles with lower levels of protein, gross energy, phosphorus and better fatty acid profile (expressed as % of total fatty acids) for H products in comparison to R foods: PUFA, 38.91 vs 24.03, P<0.01; Ï3, 5.70 vs 2.58, P<0.01; Ï6, 33.22 vs 21.63, P<0.01; DHA, 2.85 vs 0.16, P<0.05; CLA, 0.24 vs 0.08, P<0.05, for H and R respectively. This study suggests that the differences observed in the fatty acids composition may be attributed to fish proteins addition, but not to fish oil, in H pet foods production
Secondary flow and radial mixing modelling for CFD-based Through-Flow methods: an axial turbine application
Abstract The paper presents the theoretical bases and an application of a CFD-based Through-Flow model. The code solves the axisymmetric Euler equations and takes into account the effect of tangential blockage and body force. It inherits its numerical scheme from a state-of-the-art CFD solver (TRAF code). Blade body forces are calculated directly from the tangency condition to the meridional flow surface, which is iteratively adapted during the time-marching procedure. Dissipative forces are computed through a realistic distribution of entropy along streamlines. Both secondary flow and tip leakage effects on the meridional flow-field are included through the adoption of a concentrated vortex model, while the corresponding loss contributions are evaluated from correlations. Also, a radial mixing model considering both turbulent diffusion and spanwise convection is implemented. The accuracy of the method is assessed by comparison with CFD calculations and experimental data on the transonic CT3 turbine stage tested in the framework of the TATEF2 European project. A good agreement in terms of overall performance and radial distributions is achieved for both design and off-design operating conditions
Embodied Organizations: a Unifying Perspective in Programming Agents, Organizations and Environments
http://ceur-ws.org/Vol-627/coin_7.pdfInternational audienceMAS research pushes the notion of openness related to systems combining heterogeneous computational entities. Typically, those entities answer to different purposes and functions and their integration is a crucial issue. Starting from a comprehensive approach in developing agents, organizations and environments, this paper devises an integrated approach and describes a unifying programming model. It introduces the notion of embodied organization, which is described first focusing on the main entities as separate concerns; and, second, establishing different interaction styles aimed to seamlessly integrate the various entities in a coherent system. An integration framework, built on top of Jason, CArtAgO and Moise (as programming platforms for agents, environments and organizations resp.) is described as a suitable technology to build embodied organizations in practice
Designing Controversies and their Publics
Controversy mapping is a teaching and research method derived from the Science and Technology Studies and meant to explore and represent modern sociotechnical issues. Striving to make the intricacy of scientific debate readable for a larger public, controversy mapping is trapped in a classic simplicity/complexity trade-?âoff: how to respect the richness of controversies without designing maps too complicated to be useful? Having worked on the question for almost two years in a project bringing together social scientists and designers (emapsproject.com1), we can now propose a way out of this contradiction and suggest three ways of moving through the simplicity/complexity continuum. The first movement -?âby multiplying the number of maps and by taking into account users before the beginning and after the end of the design process-?â allows to bypass the simplicity/complexity trade-?âoff. The second movement bind together narration and exploration and allows the publics to venture in the maze of controversies unraveling the story that will guide them out. The third movement allows to involve the publics through all the phases of a cartographic campaign and to engage it again and again
Adherence to the Mediterranean Diet and Environmental Impact of the Diet on Primary School Children Living in Parma (Italy)
The key role of diet in both human health and environmental sustainability is well known. However, there is a lack of studies investigating the environmental impact of childrenâs dietary behavior. The aim of this observational study was to investigate the dietary environmental impact in a sample of primary school children living in Parma (Italy, n = 172, 8â10 years), in relation to their adherence to the Mediterranean diet (MD). Children completed a 3-day food record in both winter and spring. Dietary records were processed to obtain: (i) adherence to the MD and (ii) mean daily carbon and ecological footprints. Adherence to the MD was similar in winter and spring, with almost half of the participants showing a medium MD score. Carbon and ecological footprints were higher during winter, and the main dietary contributors were red and processed meat for both indexes. A small positive correlation was observed between adherence to the MD and total carbon and ecological footprints. This study provided the first analysis of the relationship between adherence to the MD and environmental impact of primary school children. Further research is needed to better investigate the environmental impact of primary school childrenâs diet and the possible relationship between the MD and environmental sustainability
Phytoplankton RNA/DNA and 18S rRNA/rDNA ratios in a coastal marine ecosystem
The RNA/DNA ratio is used as indicator of growth in various marine organisms and to assess physiological status at
species or community level. To evaluate the utility of the RNA/DNA ratio as a proxy of phytoplankton primary
production, the relationships between phytoplankton RNA/DNA, taxon-specific diatom and dinoflagellate 18S
rRNA/rDNA ratios and autotrophic phytoplankton biomass were investigated as a first step. Significant correlations
between all phytoplankton ratios and total phytoplankton, diatom and dinoflagellate biomass as chlorophyll a (chl a)
and carbon content were found. Diatoms showed higher correlation than dinoflagellates (18S rRNA/rDNA vs. chl
a, rs =0.74 and 0.64, P <0.001; 18S rRNA/rDNA vs. carbon, rs =0.66 and 0.53, P <0.001, respectively), because
they represented the most abundant and frequent group within sampled assemblages. Further, phytoplankton biomass
production is known to be linked to protein biosynthesis and significant relationships between RNA/DNA ratios and
protein content of phytoplankton assemblage were found (rs =0.62 and 0.52, P <0.001 for diatom and dinoflagellates,
respectively). As taxon-specific RNA/DNA ratios were correlated with biomass and protein content, our results can
be regarded as the first step toward further studies on the applicability of RNA/DNA ratios as indicators of growth
rate and primary production in phytoplankton assemblages
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