348 research outputs found

    Big Data in Critical Infrastructures Security Monitoring: Challenges and Opportunities

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    Critical Infrastructures (CIs), such as smart power grids, transport systems, and financial infrastructures, are more and more vulnerable to cyber threats, due to the adoption of commodity computing facilities. Despite the use of several monitoring tools, recent attacks have proven that current defensive mechanisms for CIs are not effective enough against most advanced threats. In this paper we explore the idea of a framework leveraging multiple data sources to improve protection capabilities of CIs. Challenges and opportunities are discussed along three main research directions: i) use of distinct and heterogeneous data sources, ii) monitoring with adaptive granularity, and iii) attack modeling and runtime combination of multiple data analysis techniques.Comment: EDCC-2014, BIG4CIP-201

    User needs elicitation via analytic hierarchy process (AHP). A case study on a Computed Tomography (CT) scanner

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    Background: The rigorous elicitation of user needs is a crucial step for both medical device design and purchasing. However, user needs elicitation is often based on qualitative methods whose findings can be difficult to integrate into medical decision-making. This paper describes the application of AHP to elicit user needs for a new CT scanner for use in a public hospital. Methods: AHP was used to design a hierarchy of 12 needs for a new CT scanner, grouped into 4 homogenous categories, and to prepare a paper questionnaire to investigate the relative priorities of these. The questionnaire was completed by 5 senior clinicians working in a variety of clinical specialisations and departments in the same Italian public hospital. Results: Although safety and performance were considered the most important issues, user needs changed according to clinical scenario. For elective surgery, the five most important needs were: spatial resolution, processing software, radiation dose, patient monitoring, and contrast medium. For emergency, the top five most important needs were: patient monitoring, radiation dose, contrast medium control, speed run, spatial resolution. Conclusions: AHP effectively supported user need elicitation, helping to develop an analytic and intelligible framework of decision-making. User needs varied according to working scenario (elective versus emergency medicine) more than clinical specialization. This method should be considered by practitioners involved in decisions about new medical technology, whether that be during device design or before deciding whether to allocate budgets for new medical devices according to clinical functions or according to hospital department

    Web-based system for assessing risk factors for falls in community-dwelling elderly people using the Analytic Hierarchy Process

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    Falls occur frequently among older people and represent the most common cause of injury-related morbidity and mortality in later life. Preventing falls is an important way to reduce injuries, hospitalizations, and injury-related morbidity and mortality among older people. The research literature has identified hundreds of risk factors for falls among elderly people. Prioritizing risk factors for falls is useful for designing effective and efficacious prevention programs. The aim of this study was to use the Analytic Hierarchy Process to develop a hierarchy of risk factors for falls based on the knowledge and experience of experts working in this field

    The use of classification and regression tree to predict 15-year survival in community-dwelling older people

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    Previous research has identified various risk factors for mortality in older people. The aim of this paper was to use Classification and Regression Tree to predict 15-year survival in community-dwelling older people. Data were obtained from a United Kingdom representative sample of 1042 community-dwelling people aged 65 and over. Outcome was time from 1985 interview to death or censorship on February 29, 2000. Classification and Regression Tree is a non-parametric technique widely used in medical domain classification. We applied CART to the set of risk-factors identified in a previous research. The selected CART model is based on age, dose of drug prescribed and handgrip measures. It predicts survival with a sensitivity rate of 76.3% and a specificity rate of 66.3%. The selection of variables are consistent with previous research. Finally, we observed the range of risk factors and their combination associated with increased and decreased mortality

    Resonant electron heating and molecular phonon cooling in single C60_{60} junctions

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    We study heating and heat dissipation of a single \c60 molecule in the junction of a scanning tunneling microscope (STM) by measuring the electron current required to thermally decompose the fullerene cage. The power for decomposition varies with electron energy and reflects the molecular resonance structure. When the STM tip contacts the fullerene the molecule can sustain much larger currents. Transport simulations explain these effects by molecular heating due to resonant electron-phonon coupling and molecular cooling by vibrational decay into the tip upon contact formation.Comment: Accepted in Phys. Rev. Let

    Pseudo-placentational endometrial hyperplasia in the bitch: Case series

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    Canine pseudo-placentational endometrial hyperplasia differs from the classical form of cystic endometrial hyperplasia for the well-organized tissue architecture resembling the canine placenta. After the discovery, it has been inconstantly reported. The present work reports the clinicopathologi-cal details of six spontaneous cases retrieved retrospectively from a large database. The lesion was found in young non-pregnant female dogs (median 2.0 years) at the end of dioestrus. It could be imaged by ultrasound and was always grossly detectable as single or multiple uterine enlargements of 2–3 cm in diameter with a villous whitish tissue growing on the mucosa and occluding the lumen. Histology confirmed the tissue architecture of the canine placenta with a basal glandular layer, a connective band, a spongy layer and a tortuous and compact labyrinth, often poorly recogniz-able. The pseudo-placentational hyperplasia is a non-inflammatory proliferative lesion although numerous mast cells inhabit the connective band, and a superimposed inflammatory infiltrate was seen in a case. Canine pseudo-placentational endometrial hyperplasia has very peculiar features, and it is a model for canine placentation and may help to better understand the cystic endometrial hyperplasia/pyometra complex

    Olfactory lateralization in homing pigeons: a GPS study on birds released with unilateral olfactory inputs

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    A large body of evidence has shown that pigeons rely on an olfactory-based navigational map when homing from unfamiliar locations. Previous studies on pigeons released with one nostril occluded highlighted an asymmetry in favour of the right nostril, particularly concerning the initial orientation performance of naïve birds. Nevertheless, all pigeons experiencing only unilateral olfactory input showed impaired homing, regardless of the side of the occluded nostril. So far this phenomenon has been documented only by observing the birds’ vanishing bearings. In the present work we recorded the flight tracks of pigeons with previous homing experience equipped with a GPS data logger and released from an unfamiliar location with the right or the left nostril occluded. The analysis of the tracks revealed that the flight path of the birds with the right nostril occluded was more tortuous than that of unmanipulated controls. Moreover, the pigeons smelling with the left nostril interrupted their journey significantly more frequently and displayed more exploratory activity than the control birds, e.g. during flights around a stopover site. These data suggest a more important involvement of the right olfactory system in processing the olfactory information needed for the operation of the navigational map

    Role of phase nanosegregation in the photoluminescence spectra of halide perovskites

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    The study of MAPbI3 phase transitions based on temperature-dependent optical spectroscopy has recently gained a huge attention. Photoluminescence (PL) investigations of the tetragonal-orthorhombic transition suggest that tetragonal nanodomains are present below the transition temperature and signatures associated with tetragonal segregations are observed. We have studied the impact of phase nanosegregation across the orthorhombic-tetragonal phase transition of MAPbI3 on the system's properties employing a tight binding (TB) approach. The particle swarm optimization has been used to obtain a consistent set of TB parameters, where the target properties of the system have been derived by first-principles calculations. The theoretical results have been compared with the measured PL spectra for a temperature range going from 10 to 100 K. Our model effectively captures the carriers' localization phenomenon induced by the presence of residual tetragonal nanodomains and demonstrates that the assumption of phase nanosegregation can explain the low-energy features in the PL spectra of MAPbI3
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