Higher Institute on Territorial Systems for Innovation
PORTO Publications Open Repository TOrinoNot a member yet
91193 research outputs found
Sort by
PAISAGEM PROTEGIDA EM ÁREAS URBANAS: DUAS REALIDADES - BRASIL E ITÁLIA
No full textIn light of the countless pressures and significant interferences to which protected landscapes in cities are subjected, the main objective of the present research is to compare environmental measures aimed at the planning and management of conservation units in Brazil and Italy, particularly those related to the protection of natural resources, considering, as case studies, the Iguaçu Environmental Protection Area, in the Brazilian context (Curitiba, Paraná) and the Po Fluvial Park, in the Italian context (Turin region). Using a multi-method system, the investigation starts by defining the theoretical basis of the subject, which is divided into conceptual, institutional and legislative modules. Following a detailed description of the methodological structure, the study areas are characterized and the changes in their physical, biological and anthropic components, in the period between 2000 and 2012, are interpreted. Next, the environmental vulnerability of the study areas is assessed based on an analysis of physical susceptibility, biological fragility and anthropic pressure as well as an interpretation of the connectivity networks among forest fragments. With a view to improving the basis for planning and management of conservation units within the urban management process, the compatibility between the results obtained and the proposed zoning for the protected areas studied is analyzed. The main findings are that, at the regional level, environmental vulnerability in both conservation units is homogeneously distributed among the classes. In the surrounding areas, low levels of physical susceptibility and biological fragility are identified, associated to high levels of anthropic pressure, resulting in reduced vulnerability. The specific areas, in each protected area, have high physical susceptibility. However, reduced biological fragility and higher anthropic pressure are observed in Iguaçu Environmental Protection Area, resulting in lower vulnerability than in Po Fluvial Park. It could be inferred, from the comparative analysis of the proposed zoning, the data on environmental vulnerability and the shape of the connectivity networks, that the conditions of Po Fluvial Park are more coherent. In the Brazilian case, inconsistencies in the Service Sector are observed, as a result of the high percentage of areas with high vulnerability and connectivity. Of note is the absence of any areas with these characteristics in the Transition and Sports Sectors. Interpretation of the changes in the landscape that took place between the years 2000 and 2012 indicates greater stability in the case of the Italian park. More significant changes are observed in the Transition and Services Sectors of Iguaçu Environmental Protection Area, reflecting deficiencies in the management of these spaces. Therefore, the hypothesis that abiotic, biotic and human conditions are essential for the protection of the conservation units is confirmed. Furthermore, it is concluded that assessment of environmental vulnerability and connectivity networks are effective tools to support decision making, both inside protected areas as well as in the surrounding areas with a view to conserving biological diversity and protecting natural landscapes in the urban environmen
Physical Inspection metering and evaluation of HVAC systems efficiency in tertiary buildings
No full textSince twenty years European Union produces Directive to decrease energy consumption. The building sector is one of the most affected, since the buildings we live and work are responsible of about one third of global European energy consumption. Heating, Ventilation and air conditioning systems (HVAC systems) are often unknown by end-users. Also building owner and manager do not know deeply how the systems is composed. In the present work the writer found numerous specific diagnosis and intervention on HVAC system to dramatically decrease energy consumption. Incredible energy savings are possible by simply check and set up the right schedule and set up of HVAC system. Numerous European funded project demonstrated the effectiveness of such approach. Two European project results are described: Harmonac and iSERVcmb. Harmonac set up standards for HVAC systems inspections, the main findings are related to: general lack of information about system/components effectively installed in a building, HVAC inspections needing of a specific knowledge, not available in the market, lack of knowledge on control system by maintenance service companies, general over sizing of Heating power, Cooling power and water flow, scarce availability of logged data concerning energy consumption. BMS (Building Management System), if properly designed and installed could decrease inspection time and increase energy efficiency. Nevertheless, the inspections carried out in those years show that few BMS were able to log energy data. With a correctly installed BMS data of consumption the strategy and schedule of HVAC system should be understand, and also pointed the major energy savings opportunities. Buildings long term metering shown that HVAC inspection is fundamental to ensure efficiency of systems and, as a result, the best performance in terms of energy savings and comfort. BMS system should help in this issue, but they have to be originally designed for this purpose. Short term metering demonstrated that such approach could be a low cost solution to understand system behaviour and potential improvement. Building owner approach to system inspection shown clearly that there is a common under estimation of energy savings that could be reached by simply control strategy management. Since is necessary to demonstrate to building owner how much energy (and money) is possible to save with metering and operation control, the writer believe that the next step is to provide robust benchmark for the most common activities. With benchmark data will be easier to understand the potential of energy savings that is possible to achieve in buildings. That will convince building owner and/or financial bodies and ESCO to invest in big refurbishment of existent building stock, that are just operated "as usual.
New Techniques for Reliability Characterization of Electronic Circuits
No full textIntegrated electronic systems are increasingly used in an wide number of applications and environments, ranging from critical missions to low cost consumer products. Information processing has been thoroughly integrated into everyday objects and activities, in the so-called ubiquitous computing paradigm. This wide distribution is caused mainly by the miniaturization of semiconductor devices (transistor channel length scaling from 180 nm in 1999 to 22 nm in 2012), which allows integrating a complete system on a single chip (SoC). However, there are many difficult challenges associated with continued cost reduction, size reduction, improved performance and improved power efficiency. One of these challenges is the reliability of these electronic systems. Important research efforts are aimed at improving the reliability of semiconductors. Manufacturing processes, intrinsic aging phenomena of components and environmental stress may cause internal defects and damages during the lifetime of a system, possibly causing misbehaviours or failures. In order to guarantee product quality and consumer satisfaction, it is necessary not only to discover faults as soon as possible in the manufacturing process, but also to continuously check for their absence throughout a product lifetime. Today's modern systems have become increasingly complex to design and build, while the demand for reliability and cost effective development continues. Reliability is one of the most important attributes in all these systems, including aerospace applications, real-time control, medical care, defence equipment, transportation, communication, entertainment products, agriculture, energy and environmental systems. Growing international competition has increased the need for all designers, managers, practitioners, scientists and engineers to ensure a high level of reliability of their product before release and during mission time, at the lowest cost. The interest in reliability has been growing in recent years and this trend will continue during the next decade and beyond. With testers being expensive pieces of equipment and the cost of transistors continuously decreasing, it make sense to use some of these low-cost transistors to replace the costly test tools, whenever possible. The first low cost approach we can think about is using the devices themselves to implement their own test. This is the underlying motivation of functional Software-Based Self-Test (SBST): a fast, powerful microprocessor, which has lots of resources, could certainty help in its testing procedure. Having the outstanding advantages of enabling at-speed testing, zero area overhead and actually testing the device's operation, this approach also has some drawbacks. Even if SBST is essentially suitable for online testing (and sometimes it is the only possible approach), it requires some dedicated system memory for the functional testing data, which can reach very big sizes. Also some faults happen to be functionally untestable; i.e., you cannot detect them exclusively by running proper software routines. For this reason a combination of both functional and structural test approaches is common practise. A second natural approach to low cost testing is design for test (DfT). Add some extra (cheap) area on-chip specifically in charge of performing and managing tests. The DfT path started long ago, but it is still a key element in 2012 International Technology Roadmap for Semiconductors (ITRS)[1] test roadmap. Different sorts of DfT enable the use of low cost testers, contributing to the full checking of a device, and may also be reused for online testing purposes. Logic and Memory Built-In Self Test (BIST) schemas are usual practises. Analogue DfT, even if it is not as advances as digital one, is also an interesting strategy, especially when the analogue or mixed-signal device is integrated in a wider digital system like a SoC Finally, there ar
La gestione e l'impatto dei siti UNESCO:monitoraggio e valutazione dei siti italiani nel dibattito internazionale
No full textLa tesi analizza il mutamento nello scenario dei siti UNESCO e nella loro gestione, osservando in particolar modo quale sia la realtà italiana all'interno di tale contesto. Negli ultimi anni, infatti, la realtà della Lista del patrimonio mondiale UNESCO è notevolmente mutata, sono emerse nuove forme di valore e tipologie di patrimonio iscritto nella lista. Questi nuovi scenari richiedono nuove forme di amministrazione, sia dal punto legislativo che da quello socioeconomico. Nel primo capitolo viene descritto il quadro teorico e pratico di tali mutamenti negli anni e sono analizzati gli strumenti messi in atto in ambito internazionale per governare tali realtà complesse ed eterogenee e la loro interazione e impatto sul contesto locale di riferimento. In base al quadro fornito, nel secondo capitolo l'analisi si concentra sulla candidatura del paesaggio culturale dell'area vitivinicola delle Langhe, Monferrato e Roero visto come esempio di nuova tipologia di sito patrimonio dell'umanità e attualizzazione del dibattito teorico descritto. La larga diffusione sul territorio e la molteplicità di attori coinvolti nel processo, o dagli effetti dello stesso, hanno fatto sì che la candidatura stessa rappresentasse un fenomeno pubblico con rilevanti impatti anche di carattere sociale ed economico. Le strategie e metodologie di governance, analizzate nella teoria e nella pratica nei capitoli precedenti, necessitano di un processo di monitoraggio e valutazione, che viene approfondita all'interno della terza parte della tesi, esaminando preferibilmente le tematiche dell'efficacia della gestione e dell'impatto provocato dall'iscrizione alla lista de patrimonio mondiale e gli strumenti di studio e controllo attualmente in atto. Da tale analisi si sintetizza un modello che valuti la gestione del sito UNESCO descrivendo l'impatto generato sul territorio principalmente in termini qualitativi di rapporto con il territorio. Lo scopo è di studiare quanto le attività dei siti UNESCO, in particolare negli ambiti della conoscenza, conservazione valorizzazione e comunicazione abbiano ricadute significative sul territorio. Tale modello viene applicato ai casi studio di: Napoli, Genova, Firenze, Val d'Orcia, Pienza, Residenze Reali, Val Camonica, Alberobello. La conclusione del lavoro di ricerca riassume le considerazioni dei capitoli precedenti cercando di sintetizzare i casi analizzati in un modello per la comprensione della gestione di un sito UNESCO dalla fase di creazione dello stesso al mantenimento di tali risultati nel tempo, anche espandendo la discussione verso altre forme di patrimonio, come quello intangibile, o politiche pubbliche, come quelle rivolte all'innovazione e la creativit
Design of Algorithms and Protocols for Peer-To-Peer Streaming Systems
No full textPeer-to-Peer Streaming (P2P-TV) systems have been studied in the literature for some time and they are becoming popular among users as well. P2P-TV systems target the real time delivery of a video stream, therefore posing different challenges compared to more traditional peer-to-peer applications such as file sharing (BitTor-rent) or VoIP (Skype). This document focuses on mesh based P2P-TV systems in which the peers form a generic overlay topology at application level upon which peers exchange small "chunks" of video. In particular, we study two problems related with this kind of systems: i) how to induce peers to share their available resources - such as their available upload bandwidth - in a totally automatic and distributed way; ii) how to localize P2P-TV traffic in order to lower the load on the underlying transport network without impairing the quality of experience (QoE) perceived by users. Goal i) can be achieved playing on two key aspects of P2P-TV systems that are: • the design of the trading phase needed to exchange chunks among neighbors; • the strategy adopted by peers to choose the neighbors to connect with, i.e., the policy employed to build and maintain the overlay topology at application level. The former task has been successfully accomplished with the development of algorithms that aim at adapting the rate at which peers offer chunks to their neighbors to both peer's available upload bandwidth and to the system demand. The results presented in this document show that the automatic adjustment of transmission rate to available upload capacity reduce delivery delays of chunks, thus improving the experience of users. Focusing on the latter problem, we prove that the topological properties of the overlay have a deep effect on both users' QoE and network impact. We developed a smart, flexible and fully distributed algorithm for neighbors selection and implemented it in a real P2P-TV client. This let us compare several different strategies for overlay construction in a large campaign of test-bed experiments. Results show that we can actually achieve the goal of leading peers to efficiently share their available resources - goal i) - while keeping a good degree of traffic localization, hence lowering the load on the underlying network - goal ii). Furthermore, our experimental results show that a proper selection of the neighborhood leads to a win-win situation where the performance of the application and QoE are both improved, while the network stress is nicely reduce
Energy aware control algorithms for computer networks
No full textThe main motivation of this work is to investigate techniques to reduce the power consumption inside a network element. It is enough to consider the high energy demand associated to the telecommunication networks field. As practical consequence the power consumption has become a relevant parameter and it represents a critical constraint for the network designers looking both the whole network infrastructure and the network elements like switches, routers and servers. The PhD has been focused mainly on two research areas of interest, the first one was the power consumption inside the switching fabric of an high speed router. The target was to analyze the effect of the dynamic power inside a switching fabric, to evaluate a set of optimization strategies in order to minimize the power consumption and to achieve the best trade-off between power, high performances and packet delays; the crossbar was used as reference switching architecture for this study. Looking at the consumption side, generally speaking, it is possible to define two families of switching fabrics: �1)Bit-rate independent switching fabric, in which the consumption does not depend on the number of transported bits; this family is typical of optical switching fabrics �2)Bit-rate dependent switching fabric, where the total consumption is proportional to the data transmission bit-rate, this family is typical of electronic switching fabrics The second research activity was carried at the Alcatel-Lucent Bell Laboratories, based in New Jersey (USA) and over a period of 9 months. The study of the power consumption across several network elements that are commercially available for the "corporate" market. We started from a set of collected larger number of power measurements over these network elements and thanks to them we were able to develop a linear mathematical model to describe the power consumption of a generic network elemen
Innovative materials for high temperature structural applications: 3rd Generation γ-TiAl fabricated by Electron Beam Melting
No full textIn the aeronautics industry, the propulsion systems stand among the most advanced and critical components. Over the last 50 years, gas turbine aeroengines were subjected to intensive research to increase efficiency and reduce weight, noise and harmful emissions. Together with design optimization, breakthrough in materials science for structural applications triggered the development of the most advanced gas turbine engines. For low temperatures, basically ahead of the combustion section, lightweight Ti alloys are preferred for their good mechanical properties. For high temperatures instead, Ni-based superalloys exhibit outstanding properties up to very high temperatures despite a rather high material's density. Research have focused on enhancing to the maximum the potential of materials in gas turbine engines. According to the application, the components experience various mechanical and environmental constraints. Special designs, manufacturing process, material compositions and protective coatings have been developed to push the limits of advanced materials. Nowadays, the attention is focused on innovative materials to replace the existing Ti and Ni based alloys leading to substantial benefits. Light weight composite materials in particular were found very attractive to replace some components' Ti alloys. At higher temperatures, it is of great interest to replace Ni-based superalloys by materials with lower density and/or higher temperatures applications, which in turn would lead to substantial weight reduction and increase efficiency. At the highest temperatures range, in particular in the combustion chamber and high pressure turbine sections, ceramic based materials offer promising balance of properties. Research are dedicated to overcome the drawbacks of ceramics for such structural applications, and in particular their brittle fracture behavior, by addition of reinforcing fibers. At lower temperatures range, TiAl based intermetallics emerged as very promising materials at half the density of Ni-based superalloys. Significant weight reduction could be achieved by the introduction of TiAl based alloys for rotating components of the compressor and low pressure turbine. 2nd generation γ-TiAl alloys were lately introduced in GE's GEnx and CFM's LEAP engines. The present work concerns the fabrication by the additive manufacturing technique Electron Beam Melting of 3rd generation γ-TiAl alloys for high temperatures application in gas turbine aeroengines. EBM, building parts layer by layer according to CAD, offers many advantages compared to other manufacturing processes like casting and forging. Reported by Avio, 2nd generation γ-TiAl alloys have been successfully fabricated by EBM. To increase the material's potential, the production of 3rd generation γ-TiAl alloys Ti-(45-46)Al-2Cr-8Nb was therefore studied. The optimization of the EBM parameters led to high homogeneity and very low post-processing residual porosity ≤ 1%. The fine equiaxed microstructure after EBM could be tailored towards the desired mechanical properties by simple heat treatment, from equiaxed to duplex to fully lamellar. In particular, a duplex microstructure composed by about 80 % lamellar grains pinned at grain boundaries by fine equiaxed grains was obtained after heat treatment slightly over the α transus temperature. The study showed that addition of a higher amount of Nb significantly increased the oxidation resistance of the material, thus increasing the application temperature range of these γ-TiAl alloy
Finite element models with node-dependent kinematics for the analysis of composite beam structures
No full textThis paper presents refined one-dimensional models with node-dependent kinematics. The three-dimensional displacement field is discretized into two domains, namely cross-section domain and axis domain. The mechanical behaviors of the beam can be firstly captured by the cross-section functions then interpolated by the nodal shape functions of the beam element. Such a feature makes it possible to adopt different types of cross-section functions on each element node, obtaining node-dependent kinematic finite element models. Such models can integrate Taylor-based and Lagrange-type nodal kinematics on element level, bridging a less-refined model to a more refined model without using special coupling methods. FE governing equations of node-dependent models are derived by applying the Carrera Unified Formulation. Some numerical cases on metallic and composite beam-like structures are studied to demonstrate the effectiveness of node-dependent models in bridging a locally refined model to a global model when local effects should be accounted for