1,721,310 research outputs found
A positive energy building for the Middle East climate: ReStart4Smart Solar House at Solar Decathlon Middle East 2018
No full textThe city of Dubai (UAE), in accordance with its program of transformation into one of the most smart and sustainable cities, hosted the 2018 edition of Solar Decathlon, the first in the Middle East (SDME 2018). The harsh climate of UAE, along with the booming construction industry and energy consumptions and CO2 emissions among the world's highest, tasked participating university teams to find innovative solutions able to drive the region building sector towards a more sustainable future. Sapienza University of Rome participated, representing Italy, to SDME 2018 with the project ReStart4Smart, a full scale prototype of a single family energy positive smart home specifically designed for the Middle East climate and fully consistent with the Arab culture. This article examines the ReStart4Smart project in terms of energy strategies, architectural concept and technological solutions adopted, in order to verify, through a detailed analysis of energy simulations and monitoring carried out on the prototype built in Dubai, the expected performance levels. Results achieved demonstrate how the Restart4 Smart project represents, consistently with the Arab tradition, a valid proposal for zero-energy intelligent housing, perfectly responsive to the social demand emerging from the populations of the Middle East
Spatio-temporal ecosystem shits in the Baltic Sea: top-down control and reversibility potential
No full textThe Baltic Sea ecosystem has experienced dramatic changes in the past 40 years. Fishing pressures, intertwined with eutrophication and climate-driven hydrological changes, have triggered a rapid reorganization of the whole ecosystem. These changes have been detectable both in time and space in the Baltic seascape and presented in several scientific publications. The aim of this chapter is to review the major mechanisms of this ecosystem change, focusing on the multi-level top-down processes triggered by overfishing at the top of the food web. Focus is given to both temporal and spatial aspects of ecosystem changes. Embracing from fishery to anoxic sea-bottom conditions, this chapter furnishes an end-to-end spatio-temporal understanding of the Baltic Sea food web structure, functioning and resilience. A discussion about the potential existence of alternative stable states, and thus the capability of the system to shift back to the previous state, will be provided. The chapter finally offers considerations about the necessary interventions to reverse back the ecosystem state in view of the foreseen future hydro-climate Changes
On the advantage of centralized strategies in the three-pursuer single-evader game
No full textCooperation in multi-pursuer games is known to be useful. However, it is not easy to quantify how much it is convenient for the pursuers to play according to a centralized strategy with respect to a decentralized one. This paper provides an answer to this question, for the problem of three pursuers chasing a single evader in a planar environment. It is shown that centralized pursuit algorithms can halve the time required to capture the evader, with respect to decentralized pursuit strategies. Moreover, this limit is proven to be tight. Numerical computations of lower bounds to the ratio between the capture times of centralized and decentralized strategies, show that for several game initial conditions the benefit of playing in a centralized way may be significantly less than halving the game duration
A Two-Pursuer One-Evader Game with Equal Speed and Finite Capture Radius
No full textIn this paper, a two-pursuer one-evader game in the plane is considered. All the agents have simple motion and the same speed. As opposed to the game with superior pursuers, capture can occur in finite time only by defining a nonzero capture radius and for a subset of initial game states. Such a set is characterized and the full game solution is provided. In particular, the value function of the game and explicit expressions of the closed-loop optimal strategies of all the agents are derived. The results are validated via numerical simulations, comparing the optimal control actions with alternative strategies for both the evader and the pursuers
Green Technology for Smart Cities
No full textIn view of the enormous social and environmental changes at the global level, more and more cities worldwide have directed their development strategies towards smart policies aimed at sustainable mobility, energy upgrading of the building stock, increase of energy production from renewable sources, improvement of waste management and implementation of ICT infrastructures. The goal is to turn into Smart Cities, able to improve the quality of life of their inhabitants by offering a lasting opportunity for cultural, economic and social growth within a healthy, safe, stimulating and dynamic environment. After an overview of the role of cities in climate changes and environmental pollution worldwide, the article provides an up to date definition of Smart City and of its main expected features, focussing on technology innovation, smart governance and main financing and support programs. An analysis of the most interesting initiatives at the international level pursued by cities investigating the three main areas of Green Buildings, Smart grid-Smart lighting, and Smart mobility is given, with the objective to offer a broad reference for the identification of development sustainable plans and programs at the urban level within the current legislative framework
A Family of Switching Pursuit Strategies for a Multi-Pursuer Single-Evader Game
No full textA new family of pursuit strategies is introduced for a multi-pursuer single-evader game. By exploiting the optimal solution of the game involving two pursuers, conditions are derived under which the multi-pursuer game becomes equivalent to the two-pursuer one. This opens the possibility of designing a number of pursuit strategies in which the pursuers first try to enforce the satisfaction of the aforementioned condition and then switch to a two-pursuer game as soon as it is verified. The contribution is useful in two ways. First, new winning pursuit strategies can be devised starting from simple plans, such as pure pursuit. Moreover, the performance of existing pursuit strategies, like those based on Voronoi partitions, can be significantly improved by resorting to the corresponding switching version
La consulenza genetica in Italia: problemi, regole di consenso informato, trattamento dei dati genetici e privacy
No full textGli autori riflettono sulle implicazioni biogiuridiche legate alla consulenza genetica ed alla circolazione e diffusione dei dati genetici, anche in riferimento alla normativa italiana sulla riservatezza
Il valore del gruppo. Indagine sui rapporti tra adolescenti e parrocchie
No full textIl volume pesenta la prima ricerca organica in Italia sui gruppi adolescenziali parrocchiali. L'analisi è condotta su due piani. Da una parte vengono analizzate le modalità di formazione, di costruzione dell'identità e di comunicazione nei gruppi parrocchiali. Particolarmente rilevante risulta in proposito l'educazione alla fede (o catechesi) che viene proposta dagli operatori parrocchiali: il ruoloe lo stile dell'operatore, la forma specifica che assume la catechesi. Dall'altra parte, viene preso in considerazione il confronto con i gruppi adolescenziali informali, i quali prsentano caratteristiche in parte analoghe ed in parte diverse. Il volume propone sia una riflessione su aspetti quotidiani, spesso considerati ovvi, della vita della Chiesa, sia l'occasione per progettare iniziative concrete che potrebbero costituire passi per migliorare l'esistente
Otolith chemistry indicates recent worsened Baltic cod condition is linked to hypoxia exposure
No full textDeoxygenation worldwide is increasing in aquatic systems with implications for organisms' biology, communities and ecosystems. Eastern Baltic cod has experienced a strong decline in mean body condition (i.e. weight at a specific length) over the past 20 years with effects on the fishery relying on this resource. The decrease in cod condition has been tentatively linked in the literature to increased hypoxic areas potentially affecting habitat range, but also to benthic prey and/or cod physiology directly. To date, no studies have been performed to test these mechanisms. Using otolith trace element microchemistry and hypoxia-responding metrics based on manganese (Mn) and magnesium (Mg), we investigated the relationship between fish body condition at capture and exposure to hypoxia. Cod individuals collected after 2000 with low body condition had a higher level of Mn/Mg in the last year of life, indicating higher exposure to hypoxic waters than cod with high body condition. Moreover, lifetime exposure to hypoxia was even more strongly correlated to body condition, suggesting that condition may reflect long-term hypoxia status. These results were irrespective of fish age or sex. This implies that as Baltic cod visit poor-oxygen waters, perhaps searching for benthic food, they compromise their own performance. This study specifically sheds light on the mechanisms leading to the low condition of cod and generally points to the impact of deoxygenation on ecosystems and fisheries
Cooperative versus non-cooperative strategies in three-pursuer single-evader games
No full textThe value of cooperation in pursuit-evasion games is investigated. The considered setting is that of three pursuers chasing one evader in a planar environment. The optimal evader trajectory for a well-known non-cooperative pursuer strategy is characterized. This result is instrumental to derive upper and lower bounds to the game length, in the case in which the pursuers cooperate in the chasing strategy. It is shown that the cooperation cannot reduce the capture time by more than one half with respect to the non-cooperative case, and that such bound is tight
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