2,031 research outputs found

    Adaptive just-in-time code diversification

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    We present a method to regenerate diversified code dynamically in a Java bytecode JIT compiler, and to update the diversification frequently during the execution of the program. This way, we can significantly reduce the time frame in which attackers can let a program leak useful address space information and subsequently use the leaked information in memory exploits. A proof of concept implementation is evaluated, showing that even though code is recompiled frequently, we can achieved smaller overheads than the previous state of the art, which generated diversity only once during the whole execution of a program

    EUROPEAN METTTES PROJECT: METTTES Technology Offers (TOs) PORTFOLIO - Regional Demand Profiles collection

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    The METTTES (More Efficient Transnational Technologies Transfer in the Environmental Sector) Project,focused specifically on the environmental sector, is characterized by a new approach to estimate technological development needs, basing on an analysis of what current or forthcoming EU/national legislation stimulates demand for innovative solutions. This technology demand will be derived at regional level. The regional demand is analyzed in depth and expressed in a detailed document, Regional Demand Profile (RDP), with high-quality, commercially interesting Technology Requests which address both current and future demand (foresight).In this document are presented, for each RDP, technological solutions which have been identified, assessed and collated in a Technological Offer Portfolio. Potential donors and recipients, following intensive preparation, exchange of information and pre-qualification, were brought together at tailor-made matching events in the demand regions

    Studi storici dedicati a Orazio Cancila

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    Non accade sempre, e non è neppure necessario, che le raccolte di studi in onore di personalità del mondo degli studi trattino temi relativi o affini a quelli coltivati dalla personalità celebrata. Se, però, accade, si può certamente parlare di una felice circostanza o coincidenza, ma può accadere anche che tale circostanza o coincidenza sia significativa di qualcosa d’altro. E, ad esempio, può essere significativa del fatto che la personalità destinataria della raccolta si è posta o si è trovata al centro di sviluppi della storiografia contemporanea importanti anche perché rispondono a interessi diffusi negli studi e nella cultura del suo tempo. Della raccolta di studi per Orazio Cancila si può dire – credo – che ci si trova senz’altro in quest’ultimo caso, e, ciò, anche quando la formulazione letterale dei temi dei singoli contributi alla raccolta non sembra autorizzare una tale constatazione. ... È un bel panorama, ed è singolarmente conforme alla serie degli ampii e varii interessi storici di Cancila. (Dall'introduzione di Giuseppe Galasso

    On the conceptual design of the novel balanced rolling piston expander

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    This work presents a novel type of positive-displacement expander, named the balanced rolling piston expander. It proposes also a design procedure and assesses the mechanical behavior of a virtual prototype. The expander is conceptually capable of operating at higher fluid temperatures than other positive-displacement expanders, such as scroll- or screw-type machines. Moreover, it employs a radially balanced rotor, differently from common rolling piston technologies and does not require any timing mechanism for filling and emptying the working chambers, differently from Wankel or reciprocating solutions. The investigated virtual prototype is chosen for the study case of a small-scale heat recovery unit currently under investigation. The results indicate that a prototype of about 300 mm in diameter and 100 mm in length is capable of an ideal power of 20 kW. Moreover, vane accelerations can be relatively high but anyhow comparable to those in sliding vane machines, while pressure drops in percent terms are in general lower than 1%. Lastly, load-induced displacements are manageable by a proper radial clearance at room temperature. In brief, the balanced rolling piston expander is a promising option for small-scale power generation units operating with temperatures not achievable by common technologies and, hence, it deserves further investigation

    Searching for Ground Truth: a stepping stone in automating genre classification

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    This paper examines genre classification of documents and its role in enabling the effective automated management of digital documents by digital libraries and other repositories. We have previously presented genre classification as a valuable step toward achieving automated extraction of descriptive metadata for digital material. Here, we present results from experiments using human labellers, conducted to assist in genre characterisation and the prediction of obstacles which need to be overcome by an automated system, and to contribute to the process of creating a solid testbed corpus for extending automated genre classification and testing metadata extraction tools across genres. We also describe the performance of two classifiers based on image and stylistic modeling features in labelling the data resulting from the agreement of three human labellers across fifteen genre classes.

    Studying the evolution of AGB stars in the Gaia epoch

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    We present asymptotic giant branch (AGB) models of solar metallicity, to allow the interpretation of observations of Galactic AGB stars, whose distances should be soon available after the first release of the Gaia catalogue. We find an abrupt change in the AGB physical and chemical properties, occurring at the threshold mass to ignite hot bottom burning,i.e. 3.5M3.5M_{\odot}. Stars with mass below 3.5M3.5 M_{\odot} reach the C-star stage and eject into the interstellar medium gas enriched in carbon , nitrogen and 17O^{17}O. The higher mass counterparts evolve at large luminosities, between 3×104L3\times 10^4 L_{\odot} and 105L10^5 L_{\odot}. The mass expelled from the massive AGB stars shows the imprinting of proton-capture nucleosynthesis, with considerable production of nitrogen and sodium and destruction of 12C^{12}C and 18O^{18}O. The comparison with the most recent results from other research groups are discussed, to evaluate the robustness of the present findings. Finally, we compare the models with recent observations of galactic AGB stars, outlining the possibility offered by Gaia to shed new light on the evolution properties of this class of objects.Comment: 21 pages, 11 figure, 3 tables, accepted for publication in MNRAS (2016 July 11

    A systematic review of criteria used to report complications in soft tissue and oncologic surgical clinical research studies in dogs and cats.

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    ObjectiveTo evaluate reporting of surgical complications and other adverse events in clinical research articles describing soft tissue and oncologic surgery in dogs and cats.Study designSystematic literature review.SampleEnglish-language articles describing soft tissue and oncologic surgeries in client-owned dogs and cats published in peer-reviewed journals from 2013 to 2016.MethodsCAB, AGRICOLA, and MEDLINE databases were searched for eligible articles. Article characteristics relevant to complications were abstracted and summarized, including reported events, definitions, criteria used to classify events according to severity and time frame, and relevant citations.ResultsOne hundred fifty-one articles involving 10 522 animals were included. Canine retrospective case series of dogs predominated. Ninety-two percent of articles mentioned complications in study results, but only 7.3% defined the term complication. Articles commonly described complications according to time frame and severity, but terminology and classification criteria were highly variable, conflicting between studies, or not provided. Most (58%) reported complications could have been graded with a published veterinary adverse event classification scheme, although common intraoperative complications were notable exceptions.ConclusionDefinitions and criteria used to classify and report soft tissue and oncologic surgical complications are often absent, incomplete, or contradictory among studies.Clinical significanceLack of consistent terminology contributes to inadequate communication of important information about surgical complications. Standardization of terminology and consistency in severity scoring will improve comparative evaluation of clinical research results

    Noise Induced Phenomena in the Dynamics of Two Competing Species

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    Noise through its interaction with the nonlinearity of the living systems can give rise to counter-intuitive phenomena. In this paper we shortly review noise induced effects in different ecosystems, in which two populations compete for the same resources. We also present new results on spatial patterns of two populations, while modeling real distributions of anchovies and sardines. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. We find noise induced phenomena such as quasi-deterministic oscillations, stochastic resonance, noise delayed extinction, and noise induced pattern formation. In addition, our theoretical results are validated with experimental findings. Specifically the results, obtained by a coupled map lattice model, well reproduce the spatial distributions of anchovies and sardines, observed in a marine ecosystem. Moreover, the experimental dynamical behavior of two competing bacterial populations in a meat product and the probability distribution at long times of one of them are well reproduced by a stochastic microbial predictive model.Comment: 23 pages, 8 figures; to be published in Math. Model. Nat. Phenom. (2016

    A new approach to predict the fish fillet shelf-life in presence of natural preservative agents

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    Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS) were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets

    Modeling of Sensory Characteristics Based on the Growth of Food Spoilage Bacteria

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    During last years theoretical works shed new light and proposed new hypothesis on the mechanisms which regulate the time behaviour of biological populations in different natural systems. Despite of this, a relevant physical and biological issue such as the role of environmental variables in ecological systems is still an open question. Filling this gap of knowledge is a crucial task for a deeper comprehension of the dynamics of biological populations in real ecosystems. The aim of this work is to study how dynamics of food spoilage bacteria influences the sensory characteristics of fresh fish specimens. This topic is worth of investigation in view of a better understanding of the role played by the bacterial growth on the organoleptic properties, and becomes crucial in the context of quality evaluation and risk assessment of food products. We therefore analyze and reproduce the time behaviour, in fresh fish specimens, of sensory characteristics starting from the growth curves of two spoilage bacterial communities. The theoretical study, initially based on a deterministic model, is performed by using the temperature profiles obtained during the experimental analysis. As a first step, a model of predictive microbiology is used to reproduce the experimental behaviour of the two bacterial populations. Afterwards, the theoretical bacterial growths are converted, through suitable differential equations, into "sensory" scores, based on the Quality Index Method (QIM), a scoring system for freshness and quality sensory estimation of fishery products. As a third step, the theoretical curves of QIM scores are compared with the experimental data obtained by sensory analysis. Finally, the differential equations for QIM scores are modified by adding terms of multiplicative white noise, which mimics the effects of uncertainty and variability in sensory analysis. A better agreement between experimental and theoretical QIM scores is observed, in some cases, in the presence of suitable values of noise intensity respect to the deterministic analysis
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