798 research outputs found

    UN SISTEMA TRASLUCIDO PER IL CONTROLLO DELLA TRASPARENZA

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    Since its earliest times in the building sector, glass has performed a shutting function, allowing natural light through and a clear outside view. The evolution of production and assembly techniques has transformed glass from a simple transparent element into a system with high technological potential. Designs for dynamic (user-controlled) systems allow transparency level modulation and indoor light quantity transmission control. These provide greater comfort and also offer economic benefits. The first phase of this research has analysed and verified the performance of some translucid systems that are either currently on the market, or in experimental phase. Apart from guaranteeing the primary shutting function, such systems undertake the task of adapting energy fluxes, thus obtaining controllable illumination levels via the use of special filtering modes. In the second phase of the research the experimentation of a new system was undertaken. A prototype (patent of invention n. VI2005A00294) for controlling illumination levels was created. Essentially, the system aims to control illumination levels through systems that are less complex than those presently available. While considering the growing demand for lassoed surfaces in modern building construction, the new system bypasses certain problems present in commercial systems, such as high cost/benefit relationship and durability

    Influence of lateral load distributions on pushover analysis effectiveness

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    The effectiveness of two simple load distributions for pushover analysis recently proposed by the authors is investigated through a comparative study, involving static and dynamic analyses of seismic response of eccentrically braced frames. It is shown that in the upper floors only multimodal pushover procedures provide results close to the dynamic profile, while the proposed load patterns are always conservative in the lower floors. They over-estimate the seismic response less than the uniform distribution, representing a reliable alternative to the uniform or more sophisticated adaptive procedures proposed by seismic codes. © 2008 American Institute of Physics

    Technological performances upgrading and rehabilitation of building heritage inside the historic centre of Palermo

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    The recovery of building heritage through the containment of carbon emissions is one of the strategies pursued by the city of Palermo. This design approach becomes more paradigmatic when it’s referred to sensitive and historic buildings or urban areas, having an international interest or involved in participatory projects for the Mediterranean city, well beyond the attention that citizens attest to them. We would analyse the Volta electrical Power Station, inside the harbour area and near the Castello a mare, interested by the overall rehabilitation of Palermo waterfront. This building qualifies itself, through a retrofit hypothesis proposed by the authors of this essay, as a significant example of rehabilitation design, capable to respect memory but also to propose an improvement of energy performance, through a compatible and technological implementation that use information technology in order to verify passive strategies for internal environmental comfort, an improvement of healthiness and quality of confined environments through high-tech plant engineering choices. The results of this study is a design proposal of a system of openings and evaporative cooling, contributing to lower the internal temperature during summer

    Seismic risk assessment of residential buildings by the Heuristic vulnerability model: influence of fragility curve models and inventory scale

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    Typological-observational methods still constitute one of the most commonly applied tools for evaluation of the seismic risk and vulnerability of the existing building stock. Their efficiency is mainly related to the effectiveness of the procedure for deriving fragility curves, and the reliability and completeness of the database that describes the building stock. This paper presents a comparison between the vulnerability and damage distribution assessment provided by fragility curves used in the Macroseismic and Heuristic methods, and a comparison of exposure evaluation methodologies according to two different approaches, namely a compartment- and a building-scale survey. An application to the case study of the residential building stock in the historic center of Alcamo, a town of 45,000 inhabitants in Western Sicily (Italy), shows the major reduction in fragility provided by recalibration of the masonry buildings’ ductility values that characterize the Heuristic method. Moreover, the efficiency of the compartment scale survey approach, based on the CARTIS typological-structural characterization method of ordinary buildings in urban areas, is underlined

    CRITERI PER LA CONSERVAZIONE DELLE COPERTURE LIGNEE TRADIZIONALI DELLA SICILIA OCCIDENTALE: RECUPERO DI PRATICHE COSTRUTTIVE E MATERIALI TRADIZIONALI LOCALI

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    The paper presents the result of a researched that aimed to identifying typical wooden span roof systems in the ancient architecture of western Sicily. For this study, seventy construction built with various building techniques have been selected for their peculiarities. The research has paid particular attention to the components and the functional parts of the covering which have also been compared with the information acquired from written historical hand book. This comparison it was aimed at the individuation of the best way to build this covering structures and the possible precautionary measures aimed at preserving the wooden structures from the development of decay phenomena. The work has been developed trough historical investigations, from which have information about the building component were realized to verify trough modern theories and laboratory tests. It’s allows to evaluation the performances given from the wooden elements both under the original conditions that different stadiums of decay

    Durabilit\ue0 del legno lamellare rinforzato: un prodotto innovativo

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    La ricerca sviluppata nell\u2019ultimo decennio in edilizia si \ue8 orientata sempre pi\uf9 verso quei materiali, cosiddetti ecocompatibili o ecosostenibili, tali da dissipare il meno possibile le risorse naturali. In questo senso il legno, ed in particolare quello lamellare, \ue8 divenuto una valida alternativa alle tecnologie pi\uf9 usuali e tradizionali del cemento armato e del ferro, anche perch\ue9 rappresenta una delle poche materie prime rinnovabili. Il legno lamellare \ue8 un prodotto evoluto, un prodotto industriale che supera i difetti propri del legno massello con caratteristiche di resistenza meccanica e di durabilit\ue0 superiori, cos\uec da poter ottenere qualunque forma e dimensione. Presenta per\uf2 una rigidezza limitata rispetto ad altre tecnologie, aspetto quest\u2019ultimo, che ha determinato un vasto campo di ricerca basato sulla possibilit\ue0 di inserire elementi irrigidenti all\u2019interno della sezione resistente. La memoria presenta i risultati raggiunti nell\u2019ambito di un progetto di innovazione PIA che ha avuto l\u2019obbiettivo di sperimentare un prodotto innovativo che possa avere una maggiore rigidezza, e quindi maggiori prestazioni a parit\ue0 di costi. L\u2019impiego di materiali originali ha richiesto la verifica delle prestazioni attraverso test ciclici di prove integrate di resistenza meccanica e di invecchiamento accelerato che sono state svolte, rispettivamente, dal Dipartimento di Ingegneria Strutturale e Geotecnica e dal Dipartimento di Progetto e Costruzione Edilizia entrambi dell\u2019Universit\ue0 di Palermo. Nel seguito si illustrano le prove di invecchiamento artificiale eseguite per verificare la durabilit\ue0 dei prototipi innovativi da sperimentare

    Evaluation of innovative thermal insulation systems for a sustainable envelope

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    La memoria presenta i risultati ottenuti su sistemi di isolamento termico per l\u2019involucro edilizio. Si presentano i risultati ottenuti tramite simulazioni informatiche che hanno consentito di verificare e ottimizzare la trasmissione del calore attraverso un sistema sottovuoto in vetro per le facciate trasparenti. Inoltre la possibilit\ue0 offerta dal riciclo del materiale di scarto della potatura dell\u2019Opunthia Ficus Indica (fichi d\u2019india) che,opportunamente trattato ha permesso di ottenere un materiale isolante (Brevetto n. 1402131), in forma di pannello o in grani sfusi, (valori di coibenza termica 0.071\uad0.057 W/mK).The paper presents the results of the research on thermal insulation systems for the building casing. We present the results of computer simulations that have enabled us to verify and optimize the transmission of heat through several innovative insulation systems, such as vacuum solutions for transparent fa\ue7ades, or the possibilities offered by the recycling of waste material of Opunthia Ficus Indica (prickly pear) pruning, which, properly treated, allowed to obtain an insulating material (Patent n. 1402131), in the form of panels or bulk grains (thermal coefficient values 0.0710.057 W/mK)

    A scalable architecture for real-time monitoring of large information systems

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    Data centers supporting cloud-based services are characterized by a huge number of hardware and software resources often cooperating in complex and unpredictable ways. Understanding the state of these systems for reasons of management and service level agreement requires scalable monitoring architectures that should gather and evaluate continuosly large flows in almost real-time periods. We propose a novel monitoring architecture that, by combining a hierarchical approach with decentralized monitors, addresses these challenges. In this context, fully centralized systems do not scale to the required number of flows, while pure peer-to-peer architectures cannot provide a global view of the system state. We evaluate the monitoring architecture for computational units of gathering and evaluation in real contexts that demonstrate the scalability potential of the proposed system

    Verifiable Delegated Authorization for User-Centric Architectures and an OAuth2 Implementation

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    Delegated authorization protocols have become wide-spread to implement Web applications and services, where some popular providers managing people identity information and personal data allow their users to delegate third party Web services to access their data. In this paper, we analyze the risks related to untrusted providers not behaving correctly, and we solve this problem by proposing the first verifiable delegated authorization protocol that allows third party services to verify the correctness of users data returned by the provider. The contribution of the paper is twofold: we show how delegated authorization can be cryptographically enforced through authenticated data structures protocols, we extend the standard OAuth2 protocol by supporting efficient and verifiable delegated authorization including database updates and privileges revocation

    Assessing the overhead and scalability of system monitors for large data centers

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    Current data centers are shifting towards cloud-based architectures as a means to obtain a scalable, cost-effective, robust service platform. In spite of this, the underlying management infrastructure has grown in terms of hardware resources and software complexity, making automated resource monitoring a necessity.There are several infrastructure monitoring tools designed to scale to a very high number of physical nodes. However, these tools either collect performance measure at a low frequency (missing the chance to capture the dynamics of a short-term management task) or are simply not equipped with instrumentation specific to cloud computing and virtualization. In this scenario, monitoring the correctness and efficiency of live migrations can become a nightmare. This situation will only worsen in the future, with the increased service demand due to spreading of the user base.In this paper, we assess the scalability of a prototype monitoring subsystem for different user scenarios. We also identify all the major bottlenecks and give insight on how to remove them
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