1,721,028 research outputs found
Dove vuoi andare? Il processo di costruzione del senso di casa dei giovani migranti non accompagnati a Milano tra politiche pubbliche e pratiche di regolazione informale
Full text linkIl lavoro di ricerca sui minori stranieri non accompagnati, in due diverse comunità a Milano, riguarda le forme in cui il sistema di accoglienza media la costruzione delle reti sociali dei migranti e quali effetti questo produce sul mondo in cui gli stessi costruiscono un progressivo rapporto con il contesto in cui si trovano a vivere. Come fanno, in altre parole, a sentirsi a casa. In questo processo, che coinvolge sia ambiti spaziali che relazionali, le comunità e le la rete dei servizi locali giocano un ruolo cruciale. Secondo Ambrosini (2011), infatti, forme di regolazione micro-sociale e informale tendono ad emergere laddove l’azione di altri attori - in particolare quelli pubblici - è carente. Tuttavia, se le pratiche informali consentono un accesso più veloce al mercato del lavoro e alla casa allo stesso tempo aumentano il rischio di risultare in forme di marginalità e ghettizzazione
Distributed analytics for big data: A survey
No full textIn recent years, a constant and fast information growing has characterized digital applications in the majority of real-life scenarios. Thus, a new information asset, namely Big Data, has been defined and lead to different challenges, mainly related to data storage, management and analysis. Focusing on the last challenge, several Big Data analytics techniques have been developed, based on Machine Learning and Deep Learning paradigms. When dealing with Big Data, traditional approaches often take a lot of time to produce even a single predictive model, due to the extremely high demand of computational resources. The design of approaches specifically oriented to Big Data is required to overcome these computational issues. Most solutions rely on the deployment of Big Data analytics infrastructures on a cluster of machines and/or on parallelization techniques. When deployment and parallelization apply to Machine Learning and Deep Learning, we can refer to the terms Distributed Machine Learning and Distributed Deep Learning, respectively. We here discuss the main principles and features of Distributed Machine Learning and Distributed Deep Learning frameworks. The main contribution of this work is a survey of solutions proposed in the literature, through the investigation of selected features and capabilities. In particular, the survey provides a comparative analysis according to the following classification criteria: implemented parallelization technique, supporting device, supported architecture, implemented communication mode, working mode, and class of algorithms. The paper also gives an overview of the most commonly used criteria and metrics for the performance evaluation of analyzed frameworks; finally, some emerging but promising optimization techniques are reviewed apart from our classification
Using prolog unification to solve non-standard reasoning problems in description logics
No full textWe present a Logic Programming prototype implementation working as proof-of-concept for a unified strategy proposed in our past research to solve several non-standard reasoning problems in Description Logics (DLs), denoted by Constructive Reasoning. In order to proof both the problem-independence and the logic-independence of the adopted approach, the prototype is focused on the solution of three different problems - namely Least Common Subsumer, Concept Abduction and Concept Difference - and two different, though simple, DLs, i.e., εL and ALN. Accordingly to the implemented strategy, problems are formalized as conjunction of both subsumption and non-subsumption statements, causing the whole prototype to rely on a Prolog program solving subsumption. The program is built around a predicate, which on the one hand checks for the existence of subsumption relations between ground elements, providing boolean answers, and on the other hand, if inverted, exploits Prolog built-in unification to enumerate variable values making subsumption true between concept terms containing concept variables
Pushing the role of information in ICN
No full textThis paper proposes a semantic-based approach to naming and retrieval of content in Information-centric Networking (ICN). The approach stems from the need to realize the idea, originally conceived with ICN principles, of communication based on content exchange. In particular, the paper shows how, by adopting a vocabulary in Resource Description Framework for content description, it is possible to retrieve resources answering a request for content. An example scenario in the domain of Intelligent Transportation Systems works as proof-of-concept for the proposed approach
Inverting subsumption for constructive reasoning
No full textWe present a Logic Programming prototype implementation, working as proof-of-concept for a unified strategy proposed in our past research to solve several non-standard reasoning problems in Description Logics (DLs), denoted by Constructive Reasoning. In order to prove both the problem-independence and the logic-independence of the adopted approach, the prototype is focused on the solution of three different problems - namely Least Common Subsumer, Concept Abduction and Concept Difference - and two different, though simple and endowed with structural subsumption, DLs, i.e., EL and ALN. Accordingly to the implemented strategy, problems are formalized as conjunction of both subsumption and non-subsumption statements, causing the whole prototype to rely on a Prolog program solving subsumption. The program is built around a predicate, which on the one hand checks for the existence of subsumption relations between ground elements, providing boolean answers, and on the other hand, if inverted, exploits Prolog built-in unification to enumerate variable values making subsumption true between concept terms containing concept variables
Partial and Informative Common Subsumers in Description Logics
No full textLeast Common Subsumers in Description Logics have shown their usefulness for discovering commonalities among all concepts of a collection. Several applications are nevertheless focused on searching for properties shared by significant portions of a collection rather than by the collection as a whole. Actually, this is an issue we faced in a real case scenario that provided initial motivation for this study, namely the process of Core Competence extraction in knowledge intensive companies. The paper defines four reasoning services for the identification of meaningful common subsumers describing partial commonalities in a collection. In particular Common Sub-sumers adding informative content to the Least Common Subsumer are investigated, with reference to different DL
Semantic-based automated evaluation of company core competence
No full textCore Competence evaluation is crucial for strategical choices in knowledge intensive companies. Such a process is usually manually performed by the management on the basis of subjective criteria, which can then cause non-optimal decisions, especially in wide companies. We propose here a semantic-based approach for the automatic evaluation of Core Competence, exploiting novel reasoning services in Description Logics, extracting commonalities in a collection of resource descriptions. Such inferences aim at identifying features shared at least by a significant portion of a collection of professional profiles formalized in accordance with a logic language. We are in fact not necessarily interested in competence shared by the whole company personnel
A review of reasoning characteristics of RDF‐based Semantic Web systems
No full textPresented as a research challenge in 2001, the Semantic Web (SW) is now a mature technology, used in several cross-domain applications. One of its key benefits is a formal semantics of its RDF data format, which enables a system to validate data, infer implicit knowledge by automated reasoning, and explain it to a user; yet the analysis presented here of 71 RDF-based SW systems (out of which 17 reasoners) reveals that the exploitation of such semantics varies a lot among all SW applications. Since the simple enumeration of systems, each one with its characteristics, might result in a clueless listing, we borrow from Software Engineering the idea of maturity model, and organize our classification around it. Our model has three orthogonal dimensions: treatment of blank nodes, degree of deductive capabilities, and explanation of results. For each dimension, we define 3-4 levels of increasing exploitation of semantics, corresponding to an increasingly sophisticated output in that dimension. Each system is then classified in each dimension, based on its documentation and published articles. The distribution of systems along each dimension is depicted in the graphical abstract. We deliberately exclude resources consumption (time and space) since it is a dimension not peculiar to SW
Towards a goal-oriented approach to adaptable re-deployment of cloud-based applications
No full textDue to the on-demand and dynamic nature of Cloud, there is an increasing interest for automated management of adaptation and (possibly) re-deployment of cloud applications to realize quality requirements and evolution needs autonomously at run-time. This paper proposes a fast and automated approach for adapting and redeploying a cloud application at run-time as dictated by evolution needs and sudden changes in the operating environment conditions. The proposed approach exploits a graph-based model and an algorithm that extracts a sub-graph identifying the adaptation processes to be executed according to evolution changes. The approach is general enough to be implemented by any cloud application management framework. A TOSCA-based description of the structure and management aspects of the cloud application may be updated according to the above mentioned sub-graph. Then, this description may be processed by a TOSCA-compliant runtime environment to effectively adapt and possibly re-deploy the cloud application in an automated manner. The paper also illustrates the instantiation of this generic approach for adapting an e-commerce cloud application
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