133,149 research outputs found
LA MAPPA E LA SINTASSI: L'ESEMPLARITA' DEL TERRITORIO REGGIANO
No full textAnalisi ed interpretazione della struttura del territorio della provincia di Reggio Emilia alla luce dlla cartografia storica d riferimento, ed analisi ed interpretazione della cartografia storica in relazione alla natura del territorio raffigurat
Sharing rides with friends: a coalition formation algorithm for ridesharing
No full textWe consider the Social Ridesharing (SR) problem, where a set of commuters, connected through a social network, arrange one-time rides at short notice. In particular, we focus on the associated optimisation problem of forming cars to minimise the travel cost of the overall system modelling such problem as a graph constrained coalition formation (GCCF) problem, where the set of feasible coalitions is restricted by a graph (i.e., the social network). Moreover, we significantly extend the state of the art algorithm for GCCF, i.e., the CFSS algorithm, to solve our GCCF model of the SR problem. Our empirical evaluation uses a real dataset for both spatial (GeoLife) and social data (Twitter), to validate the applicability of our approach in a realistic application scenario. Empirical results show that our approach computes optimal solutions for systems of medium scale (up to 100 agents) providing significant cost reductions (up to -36.22%). Moreover, we can provide approximate solutions for very large systems (i.e., up to 2000 agents) and good quality guarantees (i.e., with an approximation ratio of 1.41 in the worst case) within minutes (i.e., 100 seconds
Attila // Dramma Serio per // musiqa // Del Sig.r Maestro Farinelli // atto Primo
No full textTitre uniforme : Farinelli, Giuseppe (1769-1836). Compositeur. [Attila]Titre propre pris à la p. de t. du 1er vol. . - Dramma serio en 2 actes. - Livret de Gaetano Rossi. - 1re représentation : Livourne, Théâtre Carlo Ludovico, mai 1806. - Rôles : Onoria (Ut 1), Idalia (Ut 1), Lotario (Ut 1), Attila (Ut 4), Gilderico (Ut 4), Aniceto (Fa 4). - Rôle supplémentaire à l'acte 1 : Semira (Ut 1). - Vl 2, vla, vlc, b, fl 2, ob 2, cl 2 ("clarini"), fag 2, cor 2, tr 2, trb, timp, grosse caisse. - Quelques p. collées ou cousues dans le vol. 1. - Copie française d'1 seule main sur papier en partie bleuté. - Rel. carton, dos et coins en parchemin vert ; pièces de titre au dos aux armes royales et la mention "Attila // Atto I° [-2° ] // Farinelli". - Acte 1 : D. 3877, acte 2 : D. 3878. - Pagination originale non complète. - Pagination ajoutée à certains endroitsPrésentation musicale : [Partition]Incipit : Ah chi ci Salva chi c'aita una SeampoAppartient à l’ensemble documentaire : RISM2Appartient à l’ensemble documentaire : RISMMssOpéra
La Locandiera // Dramma Giocoso Per Musica // Del Celebre // Sig.r Giuseppe Farinelli
No full textTitre uniforme : Farinelli, Giuseppe (1769-1836). Compositeur. [Chi la dura la vince]Farsa giocosa en 2 actes. - Livret de Gaetano Rossi, d'après Goldoni. - 1re représentation : Rome, Théâtre Valle, 2 janvier 1803, sous le titre "Chi la dura la vince". - Donné la même année, avec des modifications à Padoue sous le titre "La Locandiera", puis en 1805 à Naples sous "La Locandiera di spirito". - Rôles : Biondolina (Ut 1), Madama (Ut 1), Tiburzio (Ut 4), Cavalieri (Ut 4), Conte (Fa 4), Marchese (Fa 4). - Vl 2, vla, vlc, cb, ob 2, cl 2 ("clarini"), fag 2, cor 2, tr 2, timp, bc. - Acte 1 : D. 3885, acte 2 : D. 3886. - Rel. carton, dos et coins parcheminés. - Pièce de titre : "Farinelli // La Locandiera // Atto I. [-II.]". - Etiquette collée sur le contre-plat supérieur portant la mention ms. : "2 B[an]de 1188" . - Pagination ajoutée sur les r° uniquementPrésentation musicale : [Partition]Incipit : Gran pazienza deve avere di locanda un cameriereAppartient à l’ensemble documentaire : RISM2Appartient à l’ensemble documentaire : RISMMssOpéra
Agent-based decentralised coordination for sensor networks using the max-sum algorithm
No full textIn this paper, we consider the generic problem of how a network of physically distributed, computationally constrained devices can make coordinated decisions to maximise the effectiveness of the whole sensor network. In particular, we propose a new agent-based representation of the problem, based on the factor graph, and use state-of-the-art DCOP heuristics (i.e., DSA and the max-sum algorithm) to generate sub-optimal solutions. In more detail, we formally model a specific real-world problem where energy-harvesting sensors are deployed within an urban environment to detect vehicle movements. The sensors coordinate their sense/sleep schedules, maintaining energy neutral operation while maximising vehicle detection probability. We theoretically analyse the performance of the sensor network for various coordination strategies and show that by appropriately coordinating their schedules the sensors can achieve significantly improved system-wide performance, detecting up to 50% of the events that a randomly coordinated network fails to detect. Finally, we deploy our coordination approach in a realistic simulation of our wide area surveillance problem, comparing its performance to a number of benchmarking coordination strategies. In this setting, our approach achieves up to a 57% reduction in the number of missed vehicles (compared to an uncoordinated network). This performance is close to that achieved by a benchmark centralised algorithm (simulated annealing) and to a continuously powered network (which is an unreachable upper bound for any coordination approach)
Coalition Formation with Spatial and Temporal Constraints
No full textThe coordination of emergency responders and robots to undertake a number of tasks in disaster scenarios is a grand challenge for multi-agent systems. Central to this endeavour is the problem of forming the best teams (coalitions) of responders to perform the various tasks in the area where the disaster has struck. Moreover, these teams may have to form, disband, and reform in different areas of the disaster region. This is because in most cases there will be more tasks than agents. Hence, agents need to schedule themselves to attempt each task in turn. Second, the tasks themselves can be very complex: requiring the agents to work on them for different lengths of time and having deadlines by when they need to be completed. The problem is complicated still further when different coalitions perform tasks with different levels of efficiency. Given all these facets, we define this as The Coalition Formation with Spatial and Temporal constraints problem (CFSTP).We show that this problem is NP-hard—in particular, it contains the wellknown complex combinatorial problem of Team Orienteering as a special case. Based on this, we design a Mixed Integer Program to optimally solve small-scale instances of the CFSTP and develop new anytime heuristics that can, on average, complete 97% of the tasks for large problems (20 agents and 300 tasks). In so doing, our solutions represent the first results for CFSTP
Possible physical explanation of the intrinsic Ep,i-“intensity” correlation commonly used to “standardize” GRBs
No full textIt is recognized that very likely the correlation between peak energy Ep and bolometric intensity is intrinsic to GRBs. However, its physical origin is still debated. In this paper, we will discuss a possible interpretation of the correlation in the light of a GRB prompt emission spectral model, GRBCOMP, proposed in [L. Titarchuk, R. Farinelli, F. Frontera and L. Amati, Astrophys. J. 752 (2012) 116]. GRBCOMP is essentially a photospheric model for the prompt emission of GRBs. Its main ingredients are a thermal bath of soft seed photons and a subrelativistically expanding outflow plasma, consequence of the star explosion. The emerging spectrum is the result of two phases: first, up to the photospheric radius, Comptonization of a subrelativistic electron outflow with thermal bath of soft photons, then, convolution of the Comptonized photons in the first phase with a Green function. The result of this convolution is consistent with different physical processes, in particular Inverse Compton. GRBCOMP has been successfully tested using a significant sample of GRB time resolved spectra in the broad energy band from 2keV to 2MeV [F. Frontera, L. Amati, R. Farinelli, S. Dichiara, C. Guidorzi, R. Landi and L. Titarchuk, Astrophys. J. 779 (2013) 175]
Why America is called America
No full textReflection on the nature of maps normally tends to privilege deconstructive techniques, on the belif of the supremacy of models derived from reflections about natural language ovwer all others models. On the contrary, the paper focuses on the possibility of finding another explanation, according to which cartographic language is more important than verbal language, and is able to explain the aporias of the latter
Potatura meccanica di oliveti superintensivi
No full textPur essendo progettati per una gestione completamente meccanizzata, negli impianti ad altissima densità l’impiego della potatura agevolata può prevenire il precoce invecchiamento e mantenere elevata la produttivita
Decentralised Coordination in RoboCup Rescue
No full textEmergency responders are faced with a number of significant challenges when managing major disasters. First, the number of rescue tasks posed is usually larger than the number of responders (or agents) and the resources available to them. Second, each task is likely to require a different level of effort in order to be completed by its deadline. Third, new tasks may continually appear or disappear from the environment, thus requiring the responders to quickly recompute their allocation of resources. Fourth, forming teams or coalitions of multiple agents from different agencies is vital since no single agency will have all the resources needed to save victims, unblock roads, and extinguish the ?res which might erupt in the disaster space. Given this, coalitions have to be efficiently selected and scheduled to work across the disaster space so as to maximise the number of lives and the portion of the infrastructure saved. In particular, it is important that the selection of such coalitions should be performed in a decentralised fashion in order to avoid a single point of failure in the system. Moreover, it is critical that responders communicate only locally given they are likely to have limited battery power or minimal access to long range communication devices. Against this background, we provide a novel decentralised solution to the coalition formation process that pervades disaster management. More specifically, we model the emergency management scenario defined in the RoboCup Rescue disaster simulation platform as a Coalition Formation with Spatial and Temporal constraints (CFST) problem where agents form coalitions in order to complete tasks, each with different demands. In order to design a decentralised algorithm for CFST we formulate it as a Distributed Constraint Optimisation problem and show how to solve it using the state-of-the-art Max-Sum algorithm that provides a completely decentralised message-passing solution. We then provide a novel algorithm (F-Max-Sum) that avoids sending redundant messages and efficiently adapts to changes in the environment. In empirical evaluations, our algorithm is shown to generate better solutions than other decentralised algorithms used for this problem
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