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Lexical emergentism and the "frequency-by-regularity" interaction
Get PDFIn spite of considerable converging evidence of the role of inflectional paradigms in word acquisition and processing, little efforts have been put so far into providing detailed, algorithmic models of the interaction between lexical token frequency, paradigm frequency, paradigm regularity. We propose a neurocomputational account of this interaction, and discuss some theoretical implications of preliminary experimental results
A Neuro-Computational Approach to Understanding the Mental Lexicon
No full textHuman lexical knowledge does not appear to be organised to minimise storage, but rather to maximise processing efficiency. The way lexical information is stored reflects the way it is dynamically processed, accessed and retrieved. A detailed analysis of the way words are memorised, of the dynamic interaction between lexical representations and distribution and degrees of regularity in input data, can shed some light on the emergence of structures and relations within fully-stored words. We believe that a bottom-up investigation of low-level memory and processing functions can help understand the cognitive mechanisms that govern word processing in the mental lexicon. Neuro-computational models can play an important role in this inquiry, as they help understand the dynamic nature of lexical representations by establishing an explanatory connection between lexical structures and processing models dictated by the micro-functions of human brain. Starting from some linguistic, psycholinguistic and neuro-physiological evidence supporting a dynamic view of the mental lexicon as an integrative system, we illustrate Temporal Self Organising-Maps (TSOMs), artificial neural networks that can model such a view by memorising time series of symbolic units (words) as routinized patterns of short-term node activation. On the basis of a simple pool of principles of adaptive Hebbian synchronisation, TSOMs can perceive possible surface relations between word forms and store them by partially overlapping activation patterns, reflecting gradient levels of lexical specificity, from holistic to decompositional lexical representations. We believe that TSOMs offer an algorithmic model of the emergence of high-level, global and language-specific morphological structure through the working of low-level, language-aspecific processing functions, thus promising to bridge the persisting gap between high-level principles of grammar architecture (lexicon vs. rules), computational correlates (storage vs. processing) and low-level principles and localisations of brain functions. Extensions of the current TSOM architecture are envisaged and their theoretical implications are discussed
Progetto ClickON \u27Clinical Knowledge on action\u27 - Gli aspetti ICT: progettazione e implementazione del prototipo - Deliverable 5.4
No full textClickON - Clinical Knowledge on action: an open source web-based platform for integrated cardiological data collection (https://clickon.extrasys.it/) is a web-based interoperable open-source platform for the integrated management of clinical cardiological data, which is the result of a research and development project co-financed by the Tuscany Region (POR CReO FESR 2007-2013, Line of Action 1.5.a - 1.6.). ClickON involved the creation and link to a validated medical ontology in the cardiovascular domain with the technological platform tightly integrated with the semantic world. ClickON has been designed for the integration and management of cardiological data, implementing an open-source and web-based prototype, driven by a domain Ontology. The ClickON prototype has been implemented by Extra Srl in partnership with the Institute of Clinical Physiology of CNR in Pisa. The collaboration of Extra with IFC has been critical since the early planning of ClickON. The complementary expertise and experience of IFC and the technological expertise of Extra enabled the extension and development of an Ontology in the cardiovascular domain that support personalized medicine. This paper describes the research contributions by Extra, with particular attention to technological issues: Functionalities of the prototype for data entry web. Acquisition of available data flows (hospital discharge records, pharmaceutical, medical reports, ...) in different formats: electronic, paper, voice content. Implementation of Semantic Module based on the domain Ontology.Il progetto ClicK-ON ? il risultato di un progetto di ricerca e sviluppo cofinanziato dalla Regione Toscana nell\u27ambito del bando POR CReO FESR 2007-2013, Linea di Intervento 1.5.a - 1.6. Il progetto ? frutto di una sinergia fra pubblico e privato: Extra Srl (www.extrasrl.it) e l\u27Istituto di Fisiologia Clinica del CNR di Pisa (https://www.ifc.cnr.it). La collaborazione fra Extra ed IFC ? stata fondamentale gi? in fase di ideazione e redazione della piattaforma ClicK-ON. Le competenze ed esperienze complementari di IFC rispetto all\u27expertise tecnologica di Extra hanno consentito di approfondire e sviluppare temi legati alle Ontologie di dominio, a supporto della Medicina personalizzata. I principali obiettivi del progetto hanno riguardato: Standardizzazione e Integrazione di dati provenienti da fonti eterogenee. Informazioni chiave e principali funzionalit? della piattaforma web per pazienti con problematiche cardiovascolari. Analisi dei Requisiti con esperti di dominio. Creazione dell\u27Ontologia di ClicK-ON, a supporto semantico dei clinici e dei ricercatori nella fase di definizione della Diagnosi per il paziente. Validazione e refinement dell\u27Ontologia. Progettazione ed implementazione della piattaforma ClicK-ON in ambiente Open-Source. Nel presente documento si descrivono i contributi tecnologici a cura di Extra nell\u27ambito del progetto, con una particolare attenzione agli aspetti: Progettazione ed implementazione della piattaforma ClicK-ON in ambiente Open-Source a supporto di tali attivit?: Funzionalit? del prototipo per data entry web. Funzionalit? di acquisizione dei flussi disponibili (schede di dimissione ospedaliera, farmaceutica, referti, ?) in differenti formati: elettronico, cartaceo, contenuto vocale. Implementazione del Modulo Semantico con l\u27aggancio all\u27Ontologia
DBpedia Atlas: Mapping the Uncharted Lands of Linked Data
Get PDFIn the last few years, Linked Open Data sources have extremely increased in number. Despite their enormous potential, it is really hard to find effective and efficient ways for navigating and exploring them, mainly because of complexity and volume issues. In fact, application developers, students and researchers that are not experts in Semantic Web technologies often lose themselves in the intricacies of the Web of Data. We propose to address this problem by providing users with a map-like visualization that acts as an entry point for the exploration of a dataset. To this end, we adapt a spatialization approach, based on cartographic and information visualisation techniques, to make it suitable for Linked Data sets with a hierarchical ontological structure. Finally, we apply our method on DBpedia, implementing and testing a prototype web application that shows a comprehensive and organic representation of the more than 4 million instances defined by the dataset
Semiring-based Specification Approaches for Quantitative Security
Get PDFOur goal is to provide different semiring-based formal tools for the specification of security requirements: we quantitatively enhance the open-system approach, according to which a system is partially specified. Therefore, we suppose the existence of an unknown and possibly malicious agent that interacts in parallel with the system. Two specification frameworks are designed along two different (but still related) lines. First, by comparing the behaviour of a system with the expected one, or by checking if such system satisfies some security requirements: we investigate a novel approximate behavioural-equivalence for comparing processes behaviour, thus extending the Generalised Non Deducibility on Composition (GNDC) approach with scores. As a second result, we equip a modal logic with semiring values with the purpose to have a weight related to the satisfaction of a formula that specifies some requested property. Finally, we generalise the classical partial model-checking function, and we name it as quantitative partial model-checking in such a way to point out the necessary and sufficient conditions that a system has to satisfy in order to be considered as secure, with respect to a fixed security/functionality threshold-value
Offloading Cellular Traffic with Opportunistic Networks: A Feasibility Study
Get PDFThe widespread diffusion of powerful mobile devices with diverse networking and multimedia capabilities, and the associated blossoming of content-centric multimedia services is contributing to the exponential increase of data traffic in cellular networks. Mobile data offloading is a promising technique to cope with these problems, which allows to deliver data originally targeted for cellular networks to complementary networking technologies. Among the various forms of mobile data offloading in this study we focus on offloading through opportunistic networks. Differently from previous studies in this field we evaluate the efficiency of opportunistic offloading schemes by using a real cellular traffic dataset collected in a large metropolitan area over a period of one month. We focus our analysis on video requests for popular video providers, and we evaluate the potential benefits of using an opportunistic data dissemination scheme to request this videos from local users instead of using the cellular network. As a benchmark, we compare the performance of such system with a simple caching mechanism. We show that a simple opportunistic offloading scheme can improve the performance of the caching system even if only 10% of the users participate in the opportunistic dissemination. This means that operators could offload their network efficiently without needing to deploy additional caching infrastructure
Crisis Mapping during Natural Disasters via Text Analysis of Social Media Messages
Get PDFRecent disasters demonstrated the central role of social media during emergencies thus motivating the exploitation of such data for crisis mapping. We propose a crisis mapping system that addresses limitations of current state-of-the-art approaches by analyzing the textual content of disaster reports from a twofold perspective. A damage detection component employs a SVM classifier to detect mentions of damage among emergency reports. A novel geoparsing technique is proposed and used to perform message geolocation. We report on a case study to show how the information extracted through damage detection and message geolocation can be combined to produce accurate crisis maps. Our crisis maps clearly detect both highly and lightly damaged areas, thus opening up the possibility to prioritize rescue efforts where they are most needed
Detection of Genomic Structural Variants from Next-Generation Sequencing Data
Get PDFStructural variants are genomic rearrangements larger than 50?bp accounting for around 1% of the variation among human genomes. They impact on phenotypic diversity and play a role in various diseases including neurological/neurocognitive disorders and cancer development and progression. Dissecting structural variants from next-generation sequencing data presents several challenges and a number of approaches have been proposed in the literature. In this mini review, we describe and summarize the latest tools ? and their underlying algorithms ? designed for the analysis of whole-genome sequencing, whole-exome sequencing, custom captures, and amplicon sequencing data, pointing out the major advantages/drawbacks. We also report a summary of the most recent applications of third-generation sequencing platforms. This assessment provides a guided indication ? with particular emphasis on human genetics and copy number variants ? for researchers involved in the investigation of these genomic events
Computational analysis and experimental validation of energy saving solutions for single-screw ships.
No full textImproving the hydrodynamic efficiency of seagoing ships is nowadays motivated by both financial factors related to the cost of fuel and environmental issues at the basis of more and more stringent regulations about gas emissions. Many types of Energy Saving Devices (ESD) have been proposed that have the potential to determine significative power reductions on single-screw ships by means of relatively simple retrofit solutions. The present work focuses on two EDS types that are selected as representative of different ways the device interacts with the ship flow: a) Vortex generators: small fins fitted to the hull stern at some propeller diameters from the propeller plane and designed to alleviate velocity defect regions in the hull wake. b) Pre-swirl stators: large fins fitted just upstream the propeller plane and designed to impress a swirled flow that improves hull/propeller interaction Aim of the present paper is to describe the results of a computational study in which the mechanisms of fluid-dynamic interaction between these ESD solutions and the hull flow are investigated. The computational methodology proposed for this study is based on a coupled viscous/inviscid flow model in which a RANSE solver is used to analyse the hull boundary layer and wake, whereas propeller induction is predicted using an inviscid-flow Boundary Element Method (BEM). Both solvers have been developed at CNR-INSEAN and extensively validated over the last years. The coupling between RANSE and BEM is achieved via a body-force/effective inflow approach that allows to account for the unsteady interaction between hull and propeller flows. Numerical applications presented in the full paper address a 7000 DWT tanker. This test case is the subject of extensive model tests as well as computational studies mostly carried out in the context of the collaborative research project STREAMLINE (2010-2014) funded under the European Seventh Framework Programme (http://www.streamline-project.eu/). Available data include comparisons among the hydrodynamic performance of the original design and of its modifications obtained by retrofitting the original hullform with different types of ESDs, including vortex generators and pre-swirl stators. In the full-length paper, numerical results for the original design and the two retrofitted solutions will be presented and compared to available experimental data. Results of bare hull simulations will be compared with nominal wake flow measurements, whereas results of propelled-ship conditions will be analysed to determine the impact of EDSs on ship propulsion factors and on propeller response in terms of risk of cavitation and vibratory loads. Efficiency improvements that can be achieved by a propeller redesign taylored to the wakes of the retrofitted hulls will be also discussed. The comparison with model test results is intended to provide an assessment of the capability of the proposed hybrid RANSE/BEM methodology to correctly describe the effects of ESDs on the hydrodynamic performance of retrofitted ships versus the original layout
EXPERIMENTAL AND NUMERICAL INVESTIGATION OF ASYMMETRICAL BEHAVIOUR OF RUDDER / PROPELLER FOR TWIN SCREW SHIPS
Get PDFthe present work addresses the asymmetrical functioning of rudder/propeller complex of twin screw/twin rudders ships. A series of free running model test results are analysed, with the aid of some simplified numerical calculations. this analysis allows to show the asymmetrical propeller loading during manoeuvres and the considerably different rudder functioning. A possible simplified model to include these effects in manoeuvring simulators is proposed and discussed, allowing to define the needs for future research activities to further improve the understanding of the different phenomena shown