Search results for " Neighborhood"
showing 10 items of 42 documents
Network Centralities and Node Ranking
2017
An important problem in network analysis is understanding how much nodes are important in order to “propagate” the information across the input network. To this aim, many centrality measures have been proposed in the literature and our main goal here is that of providing an overview of the most important of them. In particular, we distinguish centrality measures based on walks computation from those based on shortest-paths computation. We also provide some examples in order to clarify how these measures can be calculated, with special attention to Degree Centrality, Closeness Centrality and Betweennes Centrality.
Efficient GRASP+VND and GRASP+VNS metaheuristics for the traveling repairman problem
2011
Abstract: The traveling repairman problem is a customer-centric routing problem, in which the total waiting time of the customers is minimized, rather than the total travel time of a vehicle. To date, research on this problem has focused on exact algorithms and approximation methods. This paper presents the first metaheuristic approach for the traveling repairman problem.
El Dret a la Ciutat des de l'exclusió residencial: l'evolució dels barris vulnerables de la Comunitat Valenciana
2019
El derecho a la ciudad fue un concepto empleado por primera vez por Lefebvre (1968) entendido como aquel derecho de la ciudadanía a constituir ciudades que respondan a las necesidades humanas. De este modo, las necesidades de una ciudad no son más que la manifestación expresa de las necesidades colectivas de sus residentes reflejadas en el espacio urbano y comunitario (Caravantes, 2018). A las necesidades colectivas cabe sumársele las necesidades específicas de las personas que forman parte activa e integrante de las ciudades. La concentración de tales necesidades, así como de fenómenos vinculados al ámbito residencial conllevan a la “acumulación de clases desfavorecidas en las ciudades” (S…
Walkscapes. Un’esperienza professionalizzante a Palermo
2020
In seno al dibattito scientifico disciplinare, da alcuni anni ormai, si va sempre più affermando che il campo degli studi urbani, siano essi finalizzati alla sola pratica della conoscenza o ad un progetto di trasformazione, non può più prescindere da un approccio diretto e pensato per il luogo e nel luogo. Il contributo vuole ragionare attraverso delle esperienze, alcune concluse altre ancora in atto, di ricerca-azione su uno degli approcci che si è rivelato più utile e che ha prodotto risultati molto interessanti nel processo di conoscenza e progettazione dello spazio urbano: la camminata di quartiere. Le esperienze sono nate all’interno delle attività didattiche svolte presso il Corso di …
From alternative representations to prospective visions. The administrative subdivisions in Palermo (Italy)
2016
Alternative representations of the city are not only a useful analysis tool, but they also provide elements of a conceived new version of lived space that can contribute to ameliorate the spatial justice of the city. This is even truer for intra-local spaces that are the reference scale for many public participation policies, grass-root projects and activists. In this paper, we present the case of Palermo where the administrative subdivisions of the urban space have been imposed – because of legislation about administrative decentralisation – on the historical and perceived ones. Alternative mapping shows intra-local spaces as places of identity definition and civic engagement. In our paper…
Hybridizing large neighborhood search and exact methods for generalized vehicle routing problems with time windows
2021
International audience; Delivery options are at the heart of the generalized vehicle routing problem with time windows (GVRPTW) allowing that customer requests are shipped to alternative delivery locations which can also have different time windows. Recently, the vehicle routing problem with delivery options was introduced into the scientific literature. It extends the GVRPTW by capacities of shared locations and by specifying service-level constraints defined by the customers' preferences for delivery options. The vehicle routing problem with delivery options also generalizes the vehicle routing problem with home roaming delivery locations and the vehicle routing problem with multiple time…
Voisinages tubulaires épointés et homotopie stable à l'infini
2022
We initiate a study of punctured tubular neighborhoods and homotopy theory at infinity in motivic settings. We use the six functors formalism to give an intrinsic definition of the stable motivic homotopy type at infinity of an algebraic variety. Our main computational tools include cdh-descent for normal crossing divisors, Euler classes, Gysin maps, and homotopy purity. Under-adic realization, the motive at infinity recovers a formula for vanishing cycles due to Rapoport-Zink; similar results hold for Steenbrink's limiting Hodge structures and Wildeshaus' boundary motives. Under the topological Betti realization, the stable motivic homotopy type at infinity of an algebraic variety recovers…
Neighborhood Characteristics, Alcohol Outlet Density, and Alcohol-Related Calls-for-Service: A Spatiotemporal Analysis in a Wet Drinking Country
2017
Alcohol outlets have been associated with different social problems, such as crime, violence, intimate partner violence, and child maltreatment. The spatial analysis of neighborhood availability of alcohol outlets is key for better understanding of these influences. Most studies on the spatial distribution of alcohol outlets in the community have been conducted in U.S. cities, but few studies have assessed this spatial distribution in other countries where the drinking culture may differ. The aim of this study was to analyze the spatiotemporal distribution of alcohol outlets in the city of Valencia, Spain, and its relationship with neighborhood-level characteristics, as well as to examine t…
Max–min dispersion with capacity and cost for a practical location problem
2022
Diversity and dispersion problems deal with selecting a subset of elements from a given set in such a way that their diversity is maximized. This study considers a practical location problem recently proposed in the context of max–min dispersion models. It is called the generalized dispersion problem, and it models realistic applications by introducing capacity and cost constraints. We propose two effective linear formulations for this problem, and develop a hybrid metaheuristic algorithm based on the variable neighborhood search methodology, to solve real instances. Extensive numerical computational experiments are performed to compare our hybrid metaheuristic with the state-of-art heurist…
Social housing e interazione multietnica: un’ipotesi di progetto nel centro storico di Palermo
2015
Nelle città odierne il diritto alla casa è sempre più compromesso da molteplici fattori, primo fra tutti le conseguenze della crisi economica attuale, per cui si assiste ad una diminuzione drastica del livello di reddito delle famiglie. Vi sono anche altri fenomeni che ostacolano l’accesso al mercato immobiliare in specifiche aree urbane, come la gentrification o diverse dinamiche di trasformazione del contesto urbano, come si rileva nella città di Palermo. In contesti sociali sempre più multietnici e caratterizzati dalla presenza di varie categorie di users che risiedono in città per periodi brevi o in modo saltuario (lavoratori che si spostano da una città all’altra in cerca di occupazion…