1,723,113 research outputs found
Interoperable services based on activity monitoring in ambient assisted living environments
No full textAmbient Assisted Living (AAL) is considered as the main technological solution that will enable the aged and people in recovery to maintain their independence and a consequent high quality of life for a longer period of time than would otherwise be the case. This goal is achieved by monitoring human’s activities and deploying the appropriate collection of services to set environmental features and satisfy user preferences in a given context. However, both human monitoring and services deployment are particularly hard to accomplish due to the uncertainty and ambiguity characterising human actions, and heterogeneity of hardware devices composed in an AAL system. This research addresses both the aforementioned challenges by introducing 1) an innovative system, based on Self Organising Feature Map (SOFM), for automatically classifying the resting location of a moving object in an indoor environment and 2) a strategy able to generate context-aware based Fuzzy Markup Language (FML) services in order to maximize the users’ comfort and hardware interoperability level. The overall system runs on a distributed embedded platform with a specialised ceiling- mounted video sensor for intelligent activity monitoring. The system has the ability to learn resting locations, to measure overall activity levels, to detect specific events such as potential falls and to deploy the right sequence of fuzzy services modelled through FML for supporting people in that particular context. Experimental results show less than 20% classification error in monitoring human activities and providing the right set of services, showing the robustness of our approach over others in literature with minimal power consumption
FML runtime system reference implementation
No full textTato práce se zaměřuje na návrh a implementaci interpreteru pro jazyk FML, který je využívaný na ČVUT k výuce předmětu Runtime systémy. FML je malý, dynamicky typovaný, objektově orientovaný jazyk inspirovaný jazyky Feeny a ML. Takto vzniklá referenční implementace bude obsahovat garbage collector (GC) a just-in-time (JIT) kompilátor.This thesis focuses on the design and implementation of an interpreter for the FML language which is used at CTU for teaching the Runtime systems course. FML is a small, dynamically typed, object oriented language based on Feeny and ML. The reference implementation created this way will contain a garbage collector (GC) and a just-in-time (JIT) compiler
Analysis of the effect of different surface treatments and the type of polymer matrix on the interfacial strength of fiber-metal laminates before and after drilling
No full textopenLa crescente richiesta di materiali leggeri e ad alte prestazioni ha spinto lo sviluppo dei Fiber Metal Laminates (FML), materiali compositi costituiti da una matrice (ad es. polimerica o epossidica), da fibre (ad es. fibra di vetro o carbonio) e da metallo (ad es. alluminio o magnesio).
L'adesione tra i vari elementi del composito è cruciale per garantire elevate prestazioni ed è influenzata dalle proprietà chimiche e fisiche dell'interfaccia. Il metodo di assemblaggio più diffuso per i pannelli di FML è la foratura, la quale però genera delle forze che inducono la delaminazione del composito.
La presente tesi ha come obbiettivo quello di migliorare l’adesione all’interfaccia di FML costituiti da una matrice polimerica rinforzata con fibra di vetro e inserita tra due lamine di magnesio AZ31B.
Per raggiungere questo scopo sono stati testati vari trattamenti superficiali sulla lamina di magnesio e diverse tipologie di matrice, al fine di valutare l’effetto del tipo di polimero sulla forabilità del composito.
I trattamenti superficiali studiati sono Anodizzazione, Fosfatazione e Sabbiatura con ricottura; mentre i diversi tipi di matrice utilizzati sono PA6 e PA66.
I campioni trattati con queste tecniche sono stati sottoposti a test di lap shear per confrontarne le prestazioni.
Dai risultati emersi si è deciso di escludere l'anodizzazione a causa delle scarse performance ottenute, concentrando dunque l'attenzione sui trattamenti di fosfatazione e sabbiatura con ricottura. Per confrontare in dettaglio questi due approcci, è stata condotta una serie di prove di foratura al fine di misurare con precisione le forze agenti in corrispondenza dell’interfaccia e per indagare come varino le caratteristiche di resistenza a delaminazione del laminato al variare della matrice utilizzata. Dall'analisi dei risultati è emerso che combinare una matrice polimerica ad alta resistenza termica (PA66) con un trattamento di sabbiatura con ricottura assicura una maggiore integrità strutturale del laminato
Flax fibre metal laminates (FLARE): A bio-based FML alternative combining impact resistance and vibration damping?
No full textFibre metal laminates (FML) were originally developed as a hybrid material, to create synergy between the impact resistance of metals and excellent fatigue and corrosion resistance of fibre reinforced polymers, and to overcome the shortcomings of monolithic materials. Yet, the scope of the FML concept is predominantly limited to GLAss REinforced laminates (GLARE) for aerospace structures [1]. However, with the rising concerns about climate change, and the issues of recycling glass fibre composites, a new generation of FMLs with a reduced carbon footprint should be envisaged. This can be achieved by using bio-based fibre reinforced composite layers, particularly flax fibre instead of glass fibre composite, rendering FMLs with lower embodied energy, in which aluminium layers can be easily recycled by incineration with energy recuperation of the flax composite. Flax fibres demonstrate promising specific mechanical properties compared to glass fibres, particularly regarding tensile stiffness and bending stiffness and strength. This means that flax fibres can outperform glass fibres in stiffness-based designs, and in applications in which the loading mode is predominantly in bending. This includes applications in the transportation and construction sectors as well as secondary structures for civil aircraft, such as automotive panels, flooring, and bridge decks. Additionally, flax fibre composites demonstrate high damping capabilities due to the unique hierarchical structure of these fibres. This makes them particularly suitable for applications where vibrational and acoustic damping is of interest which includes many of the above given examples. However, they also have disadvantages such as high moisture absorption that can restrict their use [2]. The FML concept would overcome these limitations and thus allow the introduction of these materials in primary structures. In this study, the combination of flax fibre reinforced epoxy with thin aluminium layers is realised as a partially biobased alternative to current FMLs, aiming to obtain primarily good vibration damping properties and improved impact resistance. The impact behaviour of the flax fibre reinforced aluminium (FLARE) will be evaluated by low velocity impact and quasi-static indentation tests to identify the role of each material constituent. The results will be compared with a predictive model based on the work of F. Morinière et al. [3]. For the damping properties, to cover a wide range of frequencies and to compare methods, the vibration absorption capacities will be measured by dynamic mechanical analysis and vibration beam tests. The results will be compared to the model predictions from the metal volume fraction method. Finally, this study will give a first overview of the properties of FLARE and will verify the validity of the predictive tools developed for conventional FMLs, which help in the design phase to optimise the structure according to specific requirementsStructural Integrity & CompositesBio-based Structures & Material
CoImp: parametric and non-parametric copula based imputation methods'' (version 2.0.1), R Software Package available on the CRAN
No full textEffects of surface treatments on AZ31B magnesium alloy to evaluate the interface strength of PA6 and PA66 matrix composite.
No full textopenNegli ultimi anni, la necessità di materiali leggeri e performanti ha portato allo sviluppo dei cosiddetti Fiber Metal Laminates (FML), ovvero dei materiali ibridi composti da uno strato di materiale polimerico rinforzato con fibre inserito tra due lamine metalliche. Quando questa nuova tipologia di materiali viene realizzata, l’adesione tra la lamiera di metallo e il materiale composito è influenzata dalle proprietà meccaniche e chimiche all’interfaccia.
In questa tesi viene presentato un nuovo approccio per la produzione e l’incollaggio di componenti di FML a base di leghe di magnesio AZ31B alternate da uno strato di matrice polimerica rinforzata con fibre di vetro, ottenuto grazie ad una pressatura a caldo.
La foratura meccanica è una delle operazioni di assemblaggio più utilizzate a cui sono sottoposti questi materiali, ma per la conformazione stessa vi possono essere danni che compromettono le prestazioni del pezzo.
Il seguente lavoro indaga come i trattamenti di lavorazione superficiale del metallo e le caratteristiche della matrice polimerica rinforzata possano influenzare le operazioni di foratura. È stato dimostrato che le superfici metalliche dotate di una certa rugosità e una matrice polimerica con una maggiore resistenza termica permettano di garantire l’integrità e la qualità dei fori ottenuti
A spatially-weighted AMH copula-based dissimilarity measure for clustering variables: An application to urban thermal efficiency
No full textInvestigating thermal energy demand is crucial for developing sustainable cities and the efficient use of renewable sources. Despite the advances made in this field, the analysis of energy data provided by smart grids is currently a demanding challenge due to their complex multivariate structure and high dimensionality. In this article, we propose a novel copula-based dissimilarity measure suitable for analyzing district heating demand and introduce a procedure to apply it to high-temporal resolution panel data. Inspired by the characteristics of the considered data, we explore the usefulness of the Ali-Mikhail-Haq copula in defining a new dissimilarity measure to cluster variables in the hierarchical framework. We show that our proposal is particularly sensitive to small dissimilarities based on tiny differences in the strength of the dependence between the involved random variables. Therefore, the measure we introduce is able to distinguish between objects with low dissimilarity better than standard rank-based dissimilarity measures. Moreover, our proposal considers a weighted version of the copula-based dissimilarity that embeds the spatial location of the involved objects. We investigate the proposed measure through Monte Carlo studies and compare it with an analogous dissimilarity measure based on Kendall's correlation. Finally, the application to real data concerning the Italian city Bozen-Bolzano makes it possible to find clusters of buildings homogeneous with respect to their main characteristics, such as energy efficiency and heating surface. In turn, our findings may support the design, expansion, and management of district heating systems
Saponins, IL12 and BCG adjuvant in the FML-vaccine formulation against murine visceral leishmaniasis
No full textThe FML antigen of Leishmania donovani, in combination with either Riedel de Haen (R), QuilA, QS21 saponins, IL12 or BCG, was used in vaccination of an outbred murine model against visceral leishmaniasis (VL). Significant and specific increases in anti-FML IgG and IgM responses were detected for all adjuvants, and in anti-FML IgG1, IgG2a and IgG2b and delayed type of hypersensitivity to L. donovani lysate (DTH), only for all saponins and IL12. The QS21-FML and QuilA-FML groups achieved the highest IgG2a response. QuilA-FML developed the strongest DTH and QS21-FML animals showed the highest serum IFN-gamma concentrations. The reduction of parasitic load in the liver in response to each FML-vaccine formulation was: 52% (P < 0.025) for BCG-FML, 73% (P < 0.005) for R-FML, 93% (P < 0.005) for QuilA-FML and 79.2% (P < 0.025) for QS21-FML treated animals, respectively. Protection was specific for R-FML and QS21-FML while the QuilA saponin treatment itself induced 69% of LDU reduction. The FML-saponin vaccines promote significant, specific and strong protective effects against murine visceral leishmaniasis. BCG-FML induced minor and non-specific protection while IL 12-FML, although enhancing the specific antibody and IDR response, failed to reduce the parasitic load of infected animals. (C) 2002 Elsevier B.V. Ltd. All rights reserved.Univ Fed Rio de Janeiro, Inst Microbiol, CCS, BR-21941590 Rio de Janeiro, BrazilUniv Estadual Paulista, Curso Med Vet, BR-16050680 São Paulo, BrazilUniv Fed Rio de Janeiro, Fac Med, Hosp Clementino Fraga Filho, Rio de Janeiro, BrazilUniv Fed Rio de Janeiro, Inst Biofis, Rio de Janeiro, BrazilUniv Estadual Paulista, Curso Med Vet, BR-16050680 São Paulo, Brazi
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