1,316 research outputs found
Simulation of a trust and reputation based mitigation protocol for a black hole style attack on VANETs
From a security standpoint, VANETs (Vehicular ad hoc Networks) are vulnerable to attacks by malicious users, due to the decentralized and open nature of the wireless system. For many of these kinds of attacks detection is unfeasible, thus making it hard to produce security. Despite their characterization as dynamically reconfigurable networks, it is nonetheless essential to identify topology and population properties that can optimise mitigation protocolsâ deployment. In this paper, we provide an algorithmic definition and simulation of a trust and mitigation based protocol to contain a Black Hole style attack on a VANET. We experimentally show its optimal working conditions: total connectivity, followed by a random network; connection to external networks; early deployment of the protocol and ranking of the message. We compare results with those of existing protocols and future work shall focus on repeated broadcasting, opportunistic message forwarding and testing on real data
Trust and distrust in contradictory information transmission
We analyse the problem of contradictory information distribution in networks of agents with positive and negative trust. The networks of interest are built by ranked agents with different epistemic attitudes. In this context, positive trust is a property of the communication between agents required when message passing is executed bottom-up in the hierarchy, or as a result of a sceptic agent checking information. These two situations are associated with a confirmation procedure that has an epistemic cost. Negative trust results from refusing verification, either of contradictory information or because of a lazy attitude. We offer first a natural deduction system called SecureNDsim to model these interactions and consider some meta-theoretical properties of its derivations. We then implement it in a NetLogo simulation to test experimentally its formal properties. Our analysis concerns in particular: conditions for consensus-reaching transmissions; epistemic costs induced by confirmation and rejection operations; the influence of ranking of the initially labelled nodes on consensus and costs; complexity results
Contradictory information flow in networks with trust and distrust
We offer a proof system and a NetLogo simulation for trust and distrust in networks where contradictory information is shared by ranked lazy and sceptic agents. Trust and its negative are defined as properties of edges: the former is required when a message is passed bottom-up in the hierarchy or received by a sceptic agent; the latter is attributed to channels that require contradiction resolution, or whose terminal is a lazy agent. These procedures are associated with epistemic costs, respectively for confirmation and refutation. We describe the logic, illustrate the algorithms implemented in the model and then focus on experimental results concerning the analysis of epistemic costs, the role of the agentsâ epistemic attitude on distrust distribution and the influence of (dis)trust in reaching consensus
Life Cycle Assessment through BIM-based advanced Calculation Virtual Environment workflows
The current built stock in Europe is large and energetically inefficient due to material decay caused by lifelong use and lack of maintenance, combined. New buildings are commissioned and delivered everyday with an environmental cost, calculated using the Life Cycle Assessment methodology. The LCA is now widely requested for new assets, while existing ones are left for demolition and consequent carbon emissions released into the atmosphere, increasing the environmental crisis. In an effort to increase built stock's energy efficiency rates and decrease carbon emission, the recovery of these assets is depicted as the strategic next step for the construction sector. Both goals are achieved using data generated by dedicated construction software and processed in Calculation Virtual Environment, according to the specific needed data. The use of BIM for refurbishment design projects allows virtual construction separated by phases to simulate existing conditions of the envelope and its improvement with insulation material options. The use of one single file with clear phase definitions ensures data extraction and transference for all material options. The process is not entirely automated nevertheless it allows to save, use and share data whenever needed. The connection between data sources and databases in the cloud provides timesaving and regular updates. The research findings demonstrate the positive outcomes of modeling existing structures for energy simulation oriented to use in LCA, increasing the potential of BIM use in sensitive constructions while delivering appropriate results based on model and enriched geometry, with cost evaluation potential enabling scenario comparison for better decision making
Neoadjuvant therapy for breast cancer
Objective: To evaluate the frequency of neoadjuvant therapy (NT) in women with stage IâIII breast cancer in Italy and whether it is influenced by biological characteristics, screening history, and geographic area. Methods: Data from the High Resolution Study conducted in 7 Italian cancer registries were used; they are a representative sample of incident cancers in the study period (2009â2013). Included were 3546 women aged <85 years (groups <50, 50â69, 70â64, and 75+) with stage IâIII breast cancer at diagnosis who underwent surgery. Women were classified as receiving NT if they received chemotherapy, target therapy, and/or hormone therapy before the first surgical treatment. Logistic models were built to test the association with biological and contextual variables. Results: Only 8.2% of women (290 cases) underwent NT; the treatment decreases with increasing age (14.5% in age <50 and 2.2% in age 75+), is more frequent in women with negative receptors (14.8%), HER2-positive (15.7%), and triple-negative (15.6%). The multivariable analysis showed the probability of receiving NT is higher in stage III (odds ratio [OR] 3.83; 95% confidence interval [CI] 2.83â5.18), luminal B (OR 1.87; 95% CI 1.27â2.76), triple-negatives (OR 1.88; 95% CI 1.15â3.08), and in symptomatic cancers (OR 1.98; 95% CI 1.13â3.48). Use of NT varied among geographic areas: Reggio Emilia had the highest rates (OR 2.29; 95% CI 1.37â3.82) while Palermo had the lowest (OR 0.41; 95% CI 0.24â0.68). Conclusions: The use of NT in Italy is limited and variable. There are no signs of greater use in hospitals with more advanced care
SCAN-TO-BIM EFFICIENT APPROACH TO EXTRACT BIM MODELS FROM HIGH PRODUCTIVE INDOOR MOBILE MAPPING SURVEY
Building Information Modeling represents one of the most interesting developments in construction fields in the last 20 years. BIM process supports the creation of intelligent data that can be used throughout the life cycle of a construction project. Where a project involves a pre-existing structure, reality capture can provide the most critical information. The purpose of this paper is to describe an efficient approach to extract 3D models using high productive indoor Mobile Mapping Systems (iMMS) and an optimized scan-to-BIM workflow. The scan-to-BIM procedure allows reconstructing several elements within a digital environment preserving the features and reusing them in the development of the BIM project. The elaboration of the raw data acquired from the iMMS starts with the software HERONÂź Desktop where a SLAM algorithm runs and a 3D point cloud model is produced. The model is translated in the Gexcel ReconstructorÂź point cloud post processing software where a number of deliverables as orthophotos, blueprints and a filtered and optimized point cloud are obtained. In the proposed processing workflow, the data are introduced to Autodesk ReCapÂź, where the model can be edited and the final texturized point cloud model extracted. The identification and modeling of the 3D objects that compose the BIM model is realized in ClearEdge3D EdgeWiseTM and optimized in Autodesk RevitÂź. The data elaboration workflow implemented shows how an optimized data processing workflow allows making the scan-to-BIM procedure automatic and economically sustainable
Behavioural Differences in Sensorimotor Profiles: A Comparison of Preschool-Aged Children with Sensory Processing Disorder and Autism Spectrum Disorders
Sensory Processing Disorders (SPDs) define dysfunctions in modulating, organising, and using information from several sensory channels for regulating motor, behavioural, emotional and attention responses. Although SPD can be identified also as an isolated condition in young children, its presence in Autism Spectrum Disorder (ASD) population is really frequent. The study purpose is to explore the SPD clinical expression and the putative correlation with several behavioural aspects both in children with ASD and in those with isolated SPD. Therefore, 43 preschool-aged children (25 ASD vs. 18 SPD) were recruited, and their parents completed three questionnaires (Developmental Profile-3, Sensory Processing MeasureâPreschool, Repetitive Behaviour Scale-Revised) to evaluate behavioural alterations and developmental levels. The main result is that both ASD and SPD groups had significantly sensory-related behavioural symptoms, although ASD children seem to be more impaired in all areas. Several significant correlations were found between sensory processing difficulties and repetitive behaviours, but in the SPD group a specific relationship between Body Awareness and Ritualistic/Sameness Behaviour was found. Conversely, in the ASD group, more diffuse interlinks between sensory processing difficulties and motor behaviours were significant. In conclusion, the present study confirms the key role of sensoryâmotor skills in early diagnosis and intervention among children at risk for neurodevelopmental disorders
- âŠ