980 resultados para Software-Defined Networking, OpenFlow, rete programmabile
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Fear of Missing Out (FoMO) is a pervasive apprehension that others might be having rewarding experiences from which one is absent. Consequently, individuals experiencing FoMO wish to stay constantly in contact with what others are doing and engage with social networking sites for this purpose. In recent times, FoMO has received increased attention from psychological research, as a minority of users experiencing high levels of FoMO - particularly young people - might develop a problematic social networking site use, defined as the maladaptive and excessive use of social networking sites, resulting in symptoms associated with other addictions. According to the theoretical framework of the Interaction of Person-Affect-Cognition- Execution (I-PACE) model, FoMO and certain motives for use may foster problematic use in individuals who display unmet psychosocial needs. However, to date, the I-PACE model has only conceptualized the general higher-order mechanisms related to the development of problematic use. Consistently, the overall purpose of this dissertation was to deepen the understanding of the mediating role of FoMO between specific predisposing variables and problematic social networking sites use. Adopting a psychological approach, two empirical and exploratory cross-sectional studies, conceived as independent research, were conducted through path analysis.
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The Internet of Things (IoT) has grown rapidly in recent years, leading to an increased need for efficient and secure communication between connected devices. Wireless Sensor Networks (WSNs) are composed of small, low-power devices that are capable of sensing and exchanging data, and are often used in IoT applications. In addition, Mesh WSNs involve intermediate nodes forwarding data to ensure more robust communication. The integration of Unmanned Aerial Vehicles (UAVs) in Mesh WSNs has emerged as a promising solution for increasing the effectiveness of data collection, as UAVs can act as mobile relays, providing extended communication range and reducing energy consumption. However, the integration of UAVs and Mesh WSNs still poses new challenges, such as the design of efficient control and communication strategies. This thesis explores the networking capabilities of WSNs and investigates how the integration of UAVs can enhance their performance. The research focuses on three main objectives: (1) Ground Wireless Mesh Sensor Networks, (2) Aerial Wireless Mesh Sensor Networks, and (3) Ground/Aerial WMSN integration. For the first objective, we investigate the use of the Bluetooth Mesh standard for IoT monitoring in different environments. The second objective focuses on deploying aerial nodes to maximize data collection effectiveness and QoS of UAV-to-UAV links while maintaining the aerial mesh connectivity. The third objective investigates hybrid WMSN scenarios with air-to-ground communication links. One of the main contribution of the thesis consists in the design and implementation of a software framework called "Uhura", which enables the creation of Hybrid Wireless Mesh Sensor Networks and abstracts and handles multiple M2M communication stacks on both ground and aerial links. The operations of Uhura have been validated through simulations and small-scale testbeds involving ground and aerial devices.
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In questa tesi sperimentale si vuole evidenziare le vulnerabilità informatiche dell’architettura di rete TCP/IP. Nella sicurezza informatica spesso si dà grande rilevanza a software come gli antivirus, o ai dispositivi come i firewall, mentre si sottovaluta di mettere in sicurezza l’architettura di rete stessa. Di fatto nonostante un utente possa utilizzare un sistema operativo o un browser ritenuto estremamente sicuro, se l’amministratore di una rete non ha messo in sicurezza la rete stessa, qualunque operazione di protezione del sistema operativo (OS) o del browser risulta vana. Oltre a dimostrare che qualunque OS e browser possa essere facilmente infettato se non è stata messa in sicurezza la rete in cui naviga, si dimostrerà anche che i protocolli ritenuti sicuri come HTTPS non siano esenti da vulnerabilità. Gli attacchi informatici che si andranno a sperimentare fanno parte della tipologia Man In The Middle. L’attaccante sarà inserito all’interno della rete locale, è per questo motivo che il firewall non potrà effettuare qualunque azione di controllo. In una media/grande impresa è abbastanza frequente avere l’accesso al Wi-Fi, ad esempio come cliente nella sala d’aspetto. Spesso questa connessione Wi-Fi non è isolata dalla rete utilizzata dalla stessa azienda. In questa tesi si andranno ad evidenziare le gravi criticità di cui una configurazione del genere è afflitta. In conclusione, dopo aver analizzato le vulnerabilità dell’architettura di rete TCP/IP, si andranno ad analizzare quali funzioni attivare, e come attivarle, all’interno di switch professionali come Aruba 2930F o router board semiprofessionali come il Mikrotik 750, per mettere in sicurezza una rete locale da questo tipo di attacchi informatici.
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Nel seguente documento di tesi lo scopo della tecnologia blockchain è quello di creare un’architettura sicura per gli scambi di utility token basata su un sistema distribuito, ovvero un insieme eterogeneo formato da più calcolatori che appare all’utilizzatore come un unico dispositivo. Questa tesi descrive la progettazione e realizzazione di una rete blockchain Stellar permissioned capace di gestire transazioni di token applicabile a innumerevoli contesti all’interno di un ecosistema di pagamenti e di servizi. La tecnologia blockchain offre molteplici vantaggi tra cui la possibilità di diminuire le commissioni delle transazioni rispetto agli attuali sistemi di pagamento. L’architettura dell’infrastruttura di rete progettata prevede, oltre ai nodi della rete blockchain vera e propria, altri server che si occupano in particolare di offrire un servizio di database di custodia delle chiavi, un servizio di load balancing ed un servizio di accesso ai dati presenti nella rete tramite chiamate API fornite dai nodi Horizon. Oltre a questi è stato creato un elemento ad-hoc, ovvero il software BTKL, utilizzato per semplificare la comunicazione con la blockchain e per incrementare la sicurezza di comunicazione con il database di custodia.
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Lo sviluppo dei dispositivi mobili negli ultimi anni ha permesso la creazione di pedometri efficienti. Uno dei problemi principali nella realizzazione dei contapassi `e l’accuratezza e la precisione nei risultati. Il seguente elaborato fornisce un’analisi dettagliata dei vari studi presenti in rete a riguardo. La ricerca ha avuto scopo di riassumere le diverse scelte implementative, confrontandole tra di loro e di risaltare i punti in comune fornendo un’analisi sull’effettiva efficacia di ognuna di esse. Il focus di questo studio si concentrer`a sull’analisi di algoritmi per la rilevazione di passi calcolati non in tempo reale. L’elaborato `e stato diviso in quattro differenti fasi. Durante la prima fase vengono esposti i principali studi e le principali metodologie relative all’argomento appena descritto. Nella seconda fase viene presentata la Tassonomia, cio`e una classificazione ordinata di concetti secondo determinati criteri. Nella terza fase `e stata quindi sviluppata una applicazione Android in cui vengono implementanti gli algoritmi descritti nelle fasi precedenti. Nell’ultima fase viene testata l’applicazione attraverso l’uso di specifici test confrontando tra loro i diversi algoritmi proposti.
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The BP (Bundle Protocol) version 7 has been recently standardized by IETF in RFC 9171, but it is the whole DTN (Delay-/Disruption-Tolerant Networking) architecture, of which BP is the core, that is gaining a renewed interest, thanks to its planned adoption in future space missions. This is obviously positive, but at the same time it seems to make space agencies more interested in deployment than in research, with new BP implementations that may challenge the central role played until now by the historical BP reference implementations, such as ION and DTNME. To make Unibo research on DTN independent of space agency decisions, the development of an internal BP implementation was in order. This is the goal of this thesis, which deals with the design and implementation of Unibo-BP: a novel, research-driven BP implementation, to be released as Free Software. Unibo-BP is fully compliant with RFC 9171, as demonstrated by a series of interoperability tests with ION and DTNME, and presents a few innovations, such as the ability to manage remote DTN nodes by means of the BP itself. Unibo-BP is compatible with pre-existing Unibo implementations of CGR (Contact Graph Routing) and LTP (Licklider Transmission Protocol) thanks to interfaces designed during the thesis. The thesis project also includes an implementation of TCPCLv3 (TCP Convergence Layer version 3, RFC 7242), which can be used as an alternative to LTPCL to connect with proximate nodes, especially in terrestrial networks. Summarizing, Unibo-BP is at the heart of a larger project, Unibo-DTN, which aims to implement the main components of a complete DTN stack (BP, TCPCL, LTP, CGR). Moreover, Unibo-BP is compatible with all DTNsuite applications, thanks to an extension of the Unified API library on which DTNsuite applications are based. The hope is that Unibo-BP and all the ancillary programs developed during this thesis will contribute to the growth of DTN popularity in academia and among space agencies.
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This paper examines the spatial pattern of ill-defined causes of death across Brazilian regions, and its relationship with the evolution of completeness of the deaths registry and changes in the mortality age profile. We make use of the Brazilian Health Informatics Department mortality database and population censuses from 1980 to 2010. We applied demographic methods to evaluate the quality of mortality data for 137 small areas and correct for under-registration of death counts when necessary. The second part of the analysis uses linear regression models to investigate the relationship between, on the one hand, changes in death counts coverage and age profile of mortality, and on the other, changes in the reporting of ill-defined causes of death. The completeness of death counts coverage increases from about 80% in 1980-1991 to over 95% in 2000-2010 at the same time the percentage of ill-defined causes of deaths reduced about 53% in the country. The analysis suggests that the government's efforts to improve data quality are proving successful, and they will allow for a better understanding of the dynamics of health and the mortality transition.
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This article aimed at comparing the accuracy of linear measurement tools of different commercial software packages. Eight fully edentulous dry mandibles were selected for this study. Incisor, canine, premolar, first molar and second molar regions were selected. Cone beam computed tomography (CBCT) images were obtained with i-CAT Next Generation. Linear bone measurements were performed by one observer on the cross-sectional images using three different software packages: XoranCat®, OnDemand3D® and KDIS3D®, all able to assess DICOM images. In addition, 25% of the sample was reevaluated for the purpose of reproducibility. The mandibles were sectioned to obtain the gold standard for each region. Intraclass coefficients (ICC) were calculated to examine the agreement between the two periods of evaluation; the one-way analysis of variance performed with the post-hoc Dunnett test was used to compare each of the software-derived measurements with the gold standard. The ICC values were excellent for all software packages. The least difference between the software-derived measurements and the gold standard was obtained with the OnDemand3D and KDIS3D (-0.11 and -0.14 mm, respectively), and the greatest, with the XoranCAT (+0.25 mm). However, there was no statistical significant difference between the measurements obtained with the different software packages and the gold standard (p> 0.05). In conclusion, linear bone measurements were not influenced by the software package used to reconstruct the image from CBCT DICOM data.
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Universidade Estadual de Campinas . Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física
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The study objective was to examine differentials in time trends and predictors of deaths assigned to symptoms, signs and ill-defined conditions in comparison with other ill-defined conditions (ill-defined cardiovascular diseases, cancer and injury) in a population-based cohort study. Of 1,606 baseline participants aged 60 years and over, 524 died during 9-year follow-up and were included in this study. Deaths coded to "symptoms" declined by 77% in the period from 1997-1999 to 2003-2005. Deaths coded to other ill-defined conditions remained unchanged. The calendar period 2003-2005 (RR = 0.25; 95%CI: 0.09-0.70) and in-hospital deaths (RR = 0.16; 95%CI: 0.08-0.34) were independently associated with "symptoms", but not with other ill-defined conditions. Baseline socio-demographic characteristics and chronic diseases were not predictors of these outcomes. International and national agencies have focused on the reduction of deaths assigned to "symptoms" to improve the registration of vital statistics, while other ill-defined conditions have received little attention. Our data provide evidence supporting the need to redress this situation.
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Background: Hepatitis B virus (HBV) can be classified into nine genotypes (A-I) defined by sequence divergence of more than 8% based on the complete genome. This study aims to identify the genotypic distribution of HBV in 40 HBsAg-positive patients from Rondonia, Brazil. A fragment of 1306 bp partially comprising surface and polymerase overlapping genes was amplified by PCR. Amplified DNA was purified and sequenced. Amplified DNA was purified and sequenced on an ABI PRISM (R) 377 Automatic Sequencer (Applied Biosystems, Foster City, CA, USA). The obtained sequences were aligned with reference sequences obtained from the GenBank using Clustal X software and then edited with Se-Al software. Phylogenetic analyses were conducted by the Markov Chain Monte Carlo (MCMC) approach using BEAST v.1.5.3. Results: The subgenotypes distribution was A1 (37.1%), D3 (22.8%), F2a (20.0%), D4 (17.1%) and D2 (2.8%). Conclusions: These results for the first HBV genotypic characterization in Rondonia state are consistent with other studies in Brazil, showing the presence of several HBV genotypes that reflects the mixed origin of the population, involving descendants from Native Americans, Europeans, and Africans.
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Background: Adequate nutrition plays an important role in bone mass accrual and maintenance and has been demonstrated as a significant tool for the prevention of fractures in individuals with osteoporosis. Objective: The aim of the present study was to evaluate bone health-related nutrients intake and its association with osteoporotic fractures in a representative sample of 2344 individuals aged 40 years or older in Brazil. Methods: In a transversal population-based study, a total of 2420 individuals over 40 years old were evaluated from March to April 2006. Participants were men and women from all socioeconomic classes and education levels living around the Brazilian territory Individuals responded a questionnaire including self reported fractures as well a 24-hour food recall. Nutrient intakes were evaluated by Nutrition Data System for Research software (NDSR, University of Minnesota, 2007). Low trauma fracture was defined as that resulting of a fall from standing height or less. Nutrient intakes adequacies were performed by using the DRI's proposed values. Statistical analysis comprises Oneway ANCOVA adjusted by age and use of nutritional supplements and multiple logistic regression. SAS software was used for statistical analysis. Results: Fractures was reported by 13% of men and 15% of women. Women with fractures presented significantly higher calcium, phosphorus and magnesium intakes. However, in all regions and socio-economical levels mean intakes of bone related nutrients were below the recommended levels. It was demonstrated that for every 100 mg/phosphorus increase the risk of fractures by 9% (OR 1.09; IC95% 1.05-1.13, p < 0.001). Conclusion: The results demonstrated inadequacies in bone related nutrients in our population as well that an increase in phosphorus intake is related to bone fractures.
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This paper presents SMarty, a variability management approach for UML-based software product lines (PL). SMarty is supported by a UML profile, the SMartyProfile, and a process for managing variabilities, the SMartyProcess. SMartyProfile aims at representing variabilities, variation points, and variants in UML models by applying a set of stereotypes. SMartyProcess consists of a set of activities that is systematically executed to trace, identify, and control variabilities in a PL based on SMarty. It also identifies variability implementation mechanisms and analyzes specific product configurations. In addition, a more comprehensive application of SMarty is presented using SEI's Arcade Game Maker PL. An evaluation of SMarty and related work are discussed.
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Biological neuronal networks constitute a special class of dynamical systems, as they are formed by individual geometrical components, namely the neurons. In the existing literature, relatively little attention has been given to the influence of neuron shape on the overall connectivity and dynamics of the emerging networks. The current work addresses this issue by considering simplified neuronal shapes consisting of circular regions (soma/axons) with spokes (dendrites). Networks are grown by placing these patterns randomly in the two-dimensional (2D) plane and establishing connections whenever a piece of dendrite falls inside an axon. Several topological and dynamical properties of the resulting graph are measured, including the degree distribution, clustering coefficients, symmetry of connections, size of the largest connected component, as well as three hierarchical measurements of the local topology. By varying the number of processes of the individual basic patterns, we can quantify relationships between the individual neuronal shape and the topological and dynamical features of the networks. Integrate-and-fire dynamics on these networks is also investigated with respect to transient activation from a source node, indicating that long-range connections play an important role in the propagation of avalanches.