449 research outputs found

    Cartografie di rischio d’inquinamento ambientale: l’area carsica di Prizzi (Monti Sicani, Sicilia)

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    Il presente lavoro riporta uno studio eseguito in un’area della Sicilia, quella di Prizzi, inclusa nella regione geologica dei Monti Sicani, dove è stata redatta una cartografia di rischio d’inquinamento per acquiferi ancora poco contaminati. L’intendimento è quello di superare il concetto di vulnerabilità intrinseca ove applicato alle aree carsiche e di privilegiare così il pericolo di contaminazione degli acquiferi in relazione con le minacce d’inquinamento in ambiente carsico. Sono stati, di conseguenza, raccolti gli elementi di rischio legati alla presenza nel territorio dei centri di pericolo, redigendo un database ed elaborando un gruppo di mappe di pericolo territoriale. Queste, unitamente alle altre informazioni, possono fornire un’opportunità alle Pubbliche Amministrazioni al fine di poter indirizzare precauzionalmente la localizzazione o lo spostamento di infrastrutture o di insediamenti potenzialmente inquinanti (reti fognarie, discariche, aree industriali...). L’obiettivo finale, quindi, è quello di tener conto della possibilità di accadimento di incidenti o addirittura di catastrofi idrogeologiche, consentendo l’opportuna ubicazione delle stesse fonti di approvvigionamento idrico.This paper resumes an experience of evaluation, in a karst inland area of Sicily, of the danger contamination of groundwater characterizing the investigated territories, trying to connect them with the potential and real occurring menaces of pollution. A protection tool is conveniently represented by territory mapping performed in GIS environment, collecting also records of contamination sources spread in the territory and through the application of special standards for the estimation of the various risk elements. The final proposal is to furnish a useful opportunity to local administrations (municipalities, provinces, regional governments) for a reliable policy and management of their territories: in fact, they can precautionarily select suitable zones to locate or also shift particular infrastructures or settlements (sewerage networks, landfills, industrial poles…), with reference to dangerous events potentially occurring close to water supply sources. In this paper, a Sicily test-site will be depicted, located in the mountainous Sicani belt, where karst aquifers show till now a relative good groundwater quality, together with a likely danger of an increasing contamination risk. In the selected zone, a mapping of territorial danger has been performed in GIS environment

    A stigmergy-based analysis of city hotspots to discover trends and anomalies in urban transportation usage

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    A key aspect of a sustainable urban transportation system is the effectiveness of transportation policies. To be effective, a policy has to consider a broad range of elements, such as pollution emission, traffic flow, and human mobility. Due to the complexity and variability of these elements in the urban area, to produce effective policies remains a very challenging task. With the introduction of the smart city paradigm, a widely available amount of data can be generated in the urban spaces. Such data can be a fundamental source of knowledge to improve policies because they can reflect the sustainability issues underlying the city. In this context, we propose an approach to exploit urban positioning data based on stigmergy, a bio-inspired mechanism providing scalar and temporal aggregation of samples. By employing stigmergy, samples in proximity with each other are aggregated into a functional structure called trail. The trail summarizes relevant dynamics in data and allows matching them, providing a measure of their similarity. Moreover, this mechanism can be specialized to unfold specific dynamics. Specifically, we identify high-density urban areas (i.e hotspots), analyze their activity over time, and unfold anomalies. Moreover, by matching activity patterns, a continuous measure of the dissimilarity with respect to the typical activity pattern is provided. This measure can be used by policy makers to evaluate the effect of policies and change them dynamically. As a case study, we analyze taxi trip data gathered in Manhattan from 2013 to 2015.Comment: Preprin

    Crisi e storia in Husserl. AttualitĂ  e inattualitĂ  della "Crisi delle scienze europee"

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    The aim of this paper is to discuss whether and to what extent Husserl’s Crisis can help us to understand the challenges of Europe’s current crisis. The paper identifies both the problematic aspects of Husserl’s analysis and its fruitful components. In this connection, special attention is paid to three themes: the relationship between philosophical thought and Europe’s crisis, the emergence of a phenomenological philosophy of history, and the political scope of the life-world. These themes are discussed with particular reference to the connection between Husserl’s philosophy of subjectivity and his conception of history

    L’informatizzazione e la divulgazione del Catasto Gregoriano e della cartografia storica di Roma

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    Il progetto d’informatizzazione del Catasto Gregoriano Urbano di Roma è stato avviato circa dieci anni fa, grazie a un finanziamento della Fondazione Cariplo, ed è ora nella sua fase conclusiva. Il progetto è stato realizzato dal Dipartimento di Studi Urbani dell’università di Roma Tre, dall’Archivio di Stato di Roma, dalla Sovrintendenza Capitolina e dall’Archivio Capitolino e l’attività di ricerca ha permesso di ricostruire l'immagine urbana ed archeologica della Roma preunitaria e post-unitaria. Le mappe del Catasto Gregoriano e i relativi brogliardi costituiscono la base del Sistema Informativo Geografico (GIS) al quale sono stati collegati altri documenti cartografici e documentali: la pianta di Roma di G.B. Nolli del 1748; un consistente numero di schede relative a documenti di archivio in materia di architettura urbana e archeologia; documenti iconografici sulla architettura della città storica. Il progetto intende conseguire un duplice obiettivo: realizzare un sistema informativo geografico in grado di contenere, gestire e divulgare i dati sulla città storica provenienti da fonti diverse; creare uno strumento web a carattere partecipativo e didattico destinato ad un’ampia platea di utenti e non solo a ricercatori e studiosi del settore. La piattaforma web e la banca dati geografica sono state integralmente realizzate con prodotti e software Open Source.The digitization of the Gregorian Urban Cadastre of Rome (Catasto Gregoriano Urbano di Roma) has started about ten years ago thanks to the funding by the Cariplo Foundation, and it is now in its final stage. The project has been implemented by the Department of Urban Studies of the “Roma Tre” University, the Archivio di Stato di Roma, the Sovrintendenza Capitolina and the Archivio Capitolino. The research has allowed to reconstruct the archaeological and urban image of Rome in the pre- and post-unification periods. The maps and registers of the Gregorian Cadastre represent the basis of the Geographic Information System (GIS), which has been linked to maps and documents from other sources: the 1748 map of Rome by G. B. Nolli, a substantial number of datasheets from archive documents related to buildings and archeology, other iconographic documents concerning the architecture of the old town. The project has a dual purpose: on the one hand, the implementation of a GIS able to store, manage and disseminate data about the historic city from different sources; on the other, the activation of a participatory and educational web tool open to a wide audience, not only to researchers and scholars of this particular field. The web platform and the geographic database have been fully implemented with Open Source products and software.Peer Reviewe

    Stigmergy-based modeling to discover urban activity patterns from positioning data

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    Positioning data offer a remarkable source of information to analyze crowds urban dynamics. However, discovering urban activity patterns from the emergent behavior of crowds involves complex system modeling. An alternative approach is to adopt computational techniques belonging to the emergent paradigm, which enables self-organization of data and allows adaptive analysis. Specifically, our approach is based on stigmergy. By using stigmergy each sample position is associated with a digital pheromone deposit, which progressively evaporates and aggregates with other deposits according to their spatiotemporal proximity. Based on this principle, we exploit positioning data to identify high density areas (hotspots) and characterize their activity over time. This characterization allows the comparison of dynamics occurring in different days, providing a similarity measure exploitable by clustering techniques. Thus, we cluster days according to their activity behavior, discovering unexpected urban activity patterns. As a case study, we analyze taxi traces in New York City during 2015

    An Emergent Approach to Text Analysis Based on a Connectionist Model and the Web

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    In this paper, we present a method to provide proactive assistance in text checking, based on usage relationships between words structuralized on the Web. For a given sentence, the method builds a connectionist structure of relationships between word n-grams. Such structure is then parameterized by means of an unsupervised and language agnostic optimization process. Finally, the method provides a representation of the sentence that allows emerging the least prominent usage-based relational patterns, helping to easily find badly-written and unpopular text. The study includes the problem statement and its characterization in the literature, as well as the proposed solving approach and some experimental use

    An Interval-Valued Approach to Business Process Simulation Based on Genetic Algorithms and the BPMN

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    Simulating organizational processes characterized by interacting human activities, resources, business rules and constraints, is a challenging task, because of the inherent uncertainty, inaccuracy, variability and dynamicity. With regard to this problem, currently available business process simulation (BPS) methods and tools are unable to efficiently capture the process behavior along its lifecycle. In this paper, a novel approach of BPS is presented. To build and manage simulation models according to the proposed approach, a simulation system is designed, developed and tested on pilot scenarios, as well as on real-world processes. The proposed approach exploits interval-valued data to represent model parameters, in place of conventional single-valued or probability-valued parameters. Indeed, an interval-valued parameter is comprehensive; it is the easiest to understand and express and the simplest to process, among multi-valued representations. In order to compute the interval-valued output of the system, a genetic algorithm is used. The resulting process model allows forming mappings at different levels of detail and, therefore, at different model resolutions. The system has been developed as an extension of a publicly available simulation engine, based on the Business Process Model and Notation (BPMN) standard

    Need (more than) two to Tango: Multiple tools to adapt to changes in oxygen availability

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    Oxygen is a fundamental element for the life of a large number of living organisms allowing an efficient energetic utilization of substrates. Organisms relying on oxygen evolved complex structures for oxygen delivery and biochemical machineries dealing with its safe utilization and the ability to overcome the potentially harmful consequences of changes in oxygen availability. On fact, cells composing complex Eukaryotic organisms are set to live within an optimum narrow range of oxygen, quite specific for each cell type. Minute modifications of oxygen availability, either positive or negative, induce the expression of specific genes, the major actors of this responses being the transcription factors HIF and Nrf2 that control the attempt to cope with low oxygen (hypoxia) or to either high oxygen or to an oxygen “overflow,” respectively. This review describes the interaction between these two transcription factors and their interaction with the transcription factor NF-kB acting as a pivotal determinant of final cel

    Enabling swarm aggregation of position data via adaptive stigmergy: a case study in urban traffic flows

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    Urban road congestion estimation is a challenge in traffic management. City traffic state can vary temporally and spatially between road links, depending on crossroads and lanes. In addition, congestion estimation requires some sort of tuning to “what is around” to trigger appropriate reactions. An adaptive aggregation mechanism of position data is therefore crucial for traffic control. We present a biologically-inspired technique to aggregate position samples coming from on-vehicle devices. In essence, each vehicle position sample is spatially and temporally augmented with digital pheromone information, locally deposited and evaporated. As a consequence, an aggregated pheromone concentration appears and stays spontaneously while many stationary vehicles and high density roads occur. Pheromone concentration is then sharpened to achieve a better distinction of critical phenomena to be triggered as detected traffic events. The overall mechanism can be actually enabled if structural parameters are correctly tuned for the given application context. Determining such correct parameters is not a simple task since different urban areas have different traffic flux and density. Thus, an appropriate tuning to adapt parameters to the specific urban area is desirable to make the estimation effective. In this paper, we show how this objective can be achieved by using differential evolution
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