12 research outputs found

    Modeling and querying spatio-temporal clinical databases with multiple granularities

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    In molti campi di ricerca, i ricercatori hanno la necessit\ue0 di memorizzare, gestire e interrogare dati spazio-temporali. Tali dati sono classici dati alfanumerici arricchiti per\uf2 con una o pi\uf9 componenti temporali, spaziali e spazio-temporali che, con diversi possibili significati, li localizzano nel tempo e/o nello spazio. Ambiti in cui tali dati spazio-temporali devono essere raccolti e gestiti sono, per esempio, la gestione del territorio o delle risorse naturali, l'epidemiologia, l'archeologia e la geografia. Pi\uf9 in dettaglio, per esempio nelle ricerche epidemiologiche, i dati spazio-temporali possono servire a rappresentare diversi aspetti delle malattie e delle loro caratteristiche, quali per esempio la loro origine, espansione ed evoluzione e i fattori di rischio potenzialmente connessi alle malattie e al loro sviluppo. Le componenti spazio-temporali dei dati possono essere considerate come dei "meta-dati" che possono essere sfruttati per introdurre nuovi tipi di analisi sui dati stessi. La gestione di questi "meta-dati" pu\uf2 avvenire all'interno di diversi framework proposti in letteratura. Uno dei concetti proposti a tal fine \ue8 quello delle granularit\ue0. In letteratura c'\ue8 ampio consenso sul concetto di granularit\ue0 temporale, di cui esistono framework basati su diversi approcci. D'altro canto, non esiste invece un consenso generale sulla definizione di un framework completo, come quello delle granularit\ue0 temporali, per le granularit\ue0 spaziali e spazio-temporali. Questa tesi ha lo scopo di riempire questo vuoto proponendo un framework per le granularit\ue0 spaziali e, basandosi su questo e su quello gi\ue0 presente in letteratura per le granularit\ue0 temporali, un framework per le granularit\ue0 spazio-temporali. I framework proposti vogliono essere completi, per questo, oltre alle definizioni dei concetti di granularit\ue0 spaziale e spazio-temporale, includono anche la definizione di diversi concetti legati alle granularit\ue0, quali per esempio le relazioni e le operazioni tra granularit\ue0. Le relazioni permettono di conoscere come granularit\ue0 diverse sono legate tra loro, costruendone anche una gerarchia. Tali informazioni sono poi utili al fine di conoscere se e come \ue8 possibile confrontare dati associati e rappresentati con granularit\ue0 diverse. Le operazioni permettono invece di creare nuove granularit\ue0 a partire da altre granularit\ue0 gi\ue0 definite nel sistema, manipolando o selezionando alcune loro componenti. Basandosi su questi framework, l'obiettivo della tesi si sposta poi sul mostrare come le granularit\ue0 possano essere utilizzate per arricchire basi di dati spazio-temporali gi\ue0 esistenti al fine di una loro migliore e pi\uf9 ricca gestione e interrogazione. A tal fine, proponiamo qui una base di dati per la gestione dei dati riguardanti le granularit\ue0 temporali, spaziali e spazio-temporali. Nella base di dati proposta possono essere rappresentate tutte le componenti di una granularit\ue0 come definito nei framework proposti. La base di dati pu\uf2 poi essere utilizzata per estendere una base di dati spazio-temporale esistente aggiungendo alle tuple di quest'ultima delle referenze alle granularit\ue0 dove quei dati possono essere localizzati nel tempo e/o nel spazio. Per dimostrare come ci\uf2 possa essere fatto, nella tesi introduciamo la base di dati sviluppata ed utilizzata dal Servizio Psichiatrico Territoriale (SPT) di Verona. Tale base di dati memorizza le informazioni su tutti i pazienti venuti in contatto con l'SPT negli ultimi 30 anni e tutte le informazioni sui loro contatti con il servizio stesso (per esempio: chiamate telefoniche, visite a domicilio, ricoveri). Parte di tali informazioni hanno una componente spazio-temporale e possono essere quindi analizzate studiandone trend e pattern nel tempo e nello spazio. Nella tesi quindi estendiamo questa base di dati psichiatrica collegandola a quella proposta per la gestione delle granularit\ue0. A questo punto i dati psichiatrici possono essere interrogati anche sulla base di vincoli spazio-temporali basati su granularit\ue0. L'interrogazione di dati spazio-temporali associati a granularit\ue0 richiede l'utilizzo di un linguaggio d'interrogazione che includa, oltre a strutture, operatori e funzioni spazio-temporali per la gestione delle componenti spazio-temporali dei dati, anche costrutti per l'utilizzo delle granularit\ue0 nelle interrogazioni. Quindi, partendo da un linguaggio d'interrogazione spazio-temporale gi\ue0 presente in letteratura, in questa tesi proponiamo anche un linguaggio d'interrogazione che permetta ad un utente di recuperare dati da una base di dati spazio-temporale anche sulla base di vincoli basati su granularit\ue0. Il linguaggio viene introdotto fornendone la sintassi e la semantica. Inoltre per mostrare l'effettivo ruolo delle granularit\ue0 nell'interrogazione di una base di dati clinica, mostreremo diversi esempi di interrogazioni, scritte con il linguaggio d'interrogazione proposto, sulla base di dati psichiatrica dell'SPT di Verona. Tali interrogazioni spazio-temporali basate su granularit\ue0 possono essere utili ai ricercatori ai fini di analisi epidemiologiche dei dati psichiatrici.In several research fields, temporal, spatial, and spatio-temporal data have to be managed and queried with several purposes. These data are usually composed by classical data enriched with a temporal and/or a spatial qualification. For instance, in epidemiology spatio-temporal data may represent surveillance data, origins of disease and outbreaks, and risk factors. In order to better exploit the time and spatial dimensions, spatio-temporal data could be managed considering their spatio-temporal dimensions as meta-data useful to retrieve information. One way to manage spatio-temporal dimensions is by using spatio-temporal granularities. This dissertation aims to show how this is possible, in particular for epidemiological spatio-temporal data. For this purpose, in this thesis we propose a framework for the definition of spatio-temporal granularities (i.e., partitions of a spatio-temporal dimension) with the aim to improve the management and querying of spatio-temporal data. The framework includes the theoretical definitions of spatial and spatio-temporal granularities (while for temporal granularities we refer to the framework proposed by Bettini et al.) and all related notions useful for their management, e.g., relationships and operations over granularities. Relationships are useful for relating granularities and then knowing how data associated with different granularities can be compared. Operations allow one to create new granularities from already defined ones, manipulating or selecting their components. We show how granularities can be represented in a database and can be used to enrich an existing spatio-temporal database. For this purpose, we conceptually and logically design a relational database for temporal, spatial, and spatio-temporal granularities. The database stores all data about granularities and their related information we defined in the theoretical framework. This database can be used for enriching other spatio-temporal databases with spatio-temporal granularities. We introduce the spatio-temporal psychiatric case register, developed by the Verona Community-based Psychiatric Service (CPS), for storing and managing information about psychiatric patient, their personal information, and their contacts with the CPS occurred in last 30 years. The case register includes both clinical and statistical information about contacts, that are also temporally and spatially qualified. We show how the case register database can be enriched with spatio-temporal granularities both extending its structure and introducing a spatio-temporal query language dealing with spatio-temporal data and spatio-temporal granularities. Thus, we propose a new spatio-temporal query language, by defining its syntax and semantics, that includes ad-hoc features and constructs for dealing with spatio-temporal granularities. Finally, using the proposed query language, we report several examples of spatio-temporal queries on the psychiatric case register showing the ``usage'' of granularities and their role in spatio-temporal queries useful for epidemiological studies

    Ontology-Based Consistent Specification of Sensor Data Acquisition Plans in Cross-Domain IoT Platforms

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    Nowadays there is an high number of IoT applications that seldom can interact with each other because developed within different Vertical IoT Platforms that adopt different standards. Several efforts are devoted to the construction of cross-layered frameworks that facilitate the interoperability among cross-domain IoT platforms for the development of horizontal applications. Even if their realization poses different challenges across all layers of the network stack, in this paper we focus on the interoperability issues that arise at the data management layer. Specifically, starting from a flexible multi-granular Spatio-Temporal-Thematic data model according to which events generated by different kinds of sensors can be represented, we propose a Semantic Virtualization approach according to which the sensors belonging to different IoT platforms and the schema of the produced event streams are described in a Domain Ontology, obtained through the extension of the well-known Semantic Sensor Network ontology. Then, these sensors can be exploited for the creation of Data Acquisition Plans by means of which the streams of events can be filtered, merged, and aggregated in a meaningful way. A notion of consistency is introduced to bind the output streams of the services contained in the Data Acquisition Plan with the Domain Ontology in order to provide a semantic description of its final output. When these plans meet the consistency constraints, it means that the data they handle are well described at the Ontological level and thus the data acquisition process over passed the interoperability barriers occurring in the original sources. The facilities of the StreamLoader prototype are finally presented for supporting the user in the Semantic Virtualization process and for the construction of meaningful Data Acquisition Plans

    Inclusão da variável tempo em sistemas de informação geográfica

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    To incorporate the temporal element in traditional geographic information systems (GIS) is a challenge that has been researched for many years and has had several proposed solutions. In order to insert time in GIS, several issues must be taken into consideration, and this study addresses some of them. Firstly, we present the stages in the development of space-time GIS. Then, we discuss the issue of data representation in GIS and present the concepts related to the temporal dimension in the context of GIS. Next, the semantics of spatio-temporal data is discussed. We then define the functions that a GIS with spatial and temporal characteristics must meet and address the issue of supporting queries. Finally, we present some of the main models developed for the representation of spatio-temporal GIS.Incorporar o elemento temporal em Sistemas de informação geográfica (SIG) é um desafio que vem sendo pesquisado por muitos anos e apresenta diversas propostas de solução. Para a inserção da variável tempo em SIG, diversas questões devem ser levadas em consideração. O presente artigo aborda algumas dessas questões. Inicialmente apresentam-se os estágios no desenvolvimento de SIG espaço-temporais, em seguida, discute-se a questão da representação de dados em SIG e depois são apresentados os conceitos relacionados à dimensão temporal no contexto de SIG. A semântica dos dados espaço-temporais também é abordada, seguida pela definição das funções a que um SIG com características espaço-temporais deve atender e a abordagem da questão do suporte a consultas. Por fim, apresentam-se alguns dos principais modelos desenvolvidos para a representação de dados espaço-temporais em SIG

    Metsävaratiedon hallinta yli ajan ja mittakaavojen

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    During the last decades there has been a global shift in forest management from a focus solely on timber management to ecosystem management that endorses all aspects of forest functions: ecological, economic and social. This has resulted in a shift in paradigm from sustained yield to sustained diversity of values, goods and benefits obtained at the same time, introducing new temporal and spatial scales into forest resource management. The purpose of the present dissertation was to develop methods that would enable spatial and temporal scales to be introduced into the storage, processing, access and utilization of forest resource data. The methods developed are based on a conceptual view of a forest as a hierarchically nested collection of objects that can have a dynamically changing set of attributes. The temporal aspect of the methods consists of lifetime management for the objects and their attributes and of a temporal succession linking the objects together. Development of the forest resource data processing method concentrated on the extensibility and configurability of the data content and model calculations, allowing for a diverse set of processing operations to be executed using the same framework. The contribution of this dissertation to the utilisation of multi-scale forest resource data lies in the development of a reference data generation method to support forest inventory methods in approaching single-tree resolution.Perinteisesti metsävarojen hyödyntämisessä on keskitytty puuvarantoon, mutta viimeisimpinä vuosikymmeninä myös ekologiset, taloudelliset ja sosiaaliset ulottuvuudet ovat saaneet painoarvoa. Metsävarojen hallinnan kannalta tämä tarkoittaa uusien ajallisten ja tilallisten ulottuvuuksien lisäämistä osaksi toimintaa. Jotta voitaisiin arvioida, onko metsävarojen käyttö vastannut sille asetettuja tavoitteita, tulisi olla mahdollista seurata metsien muuttumista ajan myötä. Tämän tutkimuksen tavoitteena olikin kehittää tiedonhallinnallisia menetelmiä ajan ja eri mittakaavojen yhdistämiseksi osaksi metsävaratietojen hallintaa. Tutkimuksessa pyrittiin vastaamaan kysymykseen kuinka nykyhetken tiedot voitaisiin säilöä käytettävässä muodossa niiden muuttuessa historiatiedoiksi, toisin sanoen tutkimuksessa etsittiin menetelmiä säilyttää ajantasaisen puustotiedon lisäksi tieto metsän menneisyydestä. Lisäksi tutkittiin kuinka metsää voitaisiin tarkastella useammista näkökulmista samanaikaisesti, esimerkiksi puiden, puuryhmien, metsäkuvioiden tai suurempien alueiden tasolla, ja kuinka nämä aikaan ja paikkaan sidotut tiedonhallinnan tarpeet voitaisiin yhdistää. Menetelmäkehitys jakaantui neljään osaan: aika-paikkatiedon tallentamisen, laskennallisen käsittelyn, tiedonhaun ja hyödyntämisen menetelmiin. Kehitetyt tiedonhallinnan menetelmät perustuvat työssä kehitettyyn käsitteelliseen malliin, jossa metsä kuvataan joukkona hierarkisia kohteita. Toisin sanoen, kullakin kohteella voi olla joukko alikohteita, joilla taas voi olla omat alikohteensa ja niin edelleen. Esimerkkinä tästä toimii edellä mainittu suuralue-metsäkuvio-puuryhmä-puu hierarkia. Oleellista menetelmien kannalta oli mahdollistaa tietosisällön ja tiedon käsittelyyn käytettävien mallien mahdollisimman vapaa muokattavuus, sillä aika tuo väistämättä mukanaan muutoksia siinä, mitä metsästä mitataan ja miten mittaustietoa malleilla käsitellään. Monimittakaavaisen metsävaratiedon hyödyntämisen menetelmien osalta tässä väitöksessä kehitettiin menetelmä, jolla voidaan tuottaa hakkuukoneen tuottamasta mittaustiedosta kustannustehokkaasti yksittäisen puun tasoa lähestyvää maastotietoa kaukokartoitusmenetelmien käyttöön

    Enhancing Exploratory Analysis across Multiple Levels of Detail of Spatiotemporal Events

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    Crimes, forest fires, accidents, infectious diseases, human interactions with mobile devices (e.g., tweets) are being logged as spatiotemporal events. For each event, its spatial location, time and related attributes are known with high levels of detail (LoDs). The LoD of analysis plays a crucial role in the user’s perception of phenomena. From one LoD to another, some patterns can be easily perceived or different patterns may be detected, thus requiring modeling phenomena at different LoDs as there is no exclusive LoD to study them. Granular computing emerged as a paradigm of knowledge representation and processing, where granules are basic ingredients of information. These can be arranged in a hierarchical alike structure, allowing the same phenomenon to be perceived at different LoDs. This PhD Thesis introduces a formal Theory of Granularities (ToG) in order to have granules defined over any domain and reason over them. This approach is more general than the related literature because these appear as particular cases of the proposed ToG. Based on this theory we propose a granular computing approach to model spatiotemporal phenomena at multiple LoDs, and called it a granularities-based model. This approach stands out from the related literature because it models a phenomenon through statements rather than just using granules to model abstract real-world entities. Furthermore, it formalizes the concept of LoD and follows an automated approach to generalize a phenomenon from one LoD to a coarser one. Present-day practices work on a single LoD driven by the users despite the fact that the identification of the suitable LoDs is a key issue for them. This PhD Thesis presents a framework for SUmmarizIng spatioTemporal Events (SUITE) across multiple LoDs. The SUITE framework makes no assumptions about the phenomenon and the analytical task. A Visual Analytics approach implementing the SUITE framework is presented, which allow users to inspect a phenomenon across multiple LoDs, simultaneously, thus helping to understand in what LoDs the phenomenon perception is different or in what LoDs patterns emerge

    Multiple-Aspect Analysis of Semantic Trajectories

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    This open access book constitutes the refereed post-conference proceedings of the First International Workshop on Multiple-Aspect Analysis of Semantic Trajectories, MASTER 2019, held in conjunction with the 19th European Conference on Machine Learning and Knowledge Discovery in Databases, ECML PKDD 2019, in Würzburg, Germany, in September 2019. The 8 full papers presented were carefully reviewed and selected from 12 submissions. They represent an interesting mix of techniques to solve recurrent as well as new problems in the semantic trajectory domain, such as data representation models, data management systems, machine learning approaches for anomaly detection, and common pathways identification

    Modélisation des bases de données multidimensionnelles : analyse par fonctions d'agrégation multiples

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    Le résumé en français n'a pas été communiqué par l'auteur.Le résumé en anglais n'a pas été communiqué par l'auteur

    Semantic and Visual Analysis of Metadata to Search and Select Heterogeneous Information Resources

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    An increasing number of activities in several disciplinary and industrial fields such as the scientific research, the industrial design and the environmental management, rely on the production and employment of informative resources representing objects, information and knowledge. The vast availability of digitalized information resources (documents, images, maps, videos, 3D model) highlights the need for appropriate methods to effectively share and employ all these resources. In particular, tools to search and select information resources produced by third parties are required to successfully achieve our daily work activities. Headway in this direction is made adopting the metadata, a description of the most relevant features characterizing the information resources. However, a plenty of features have to be considered to fully describe the information resources in sophisticated fields as those mentioned. This brings to a complexity of metadata and to a growing need for tools which face with this complexity. The thesis aims at developing methods to analyze metadata easing the search and comparison of information resources. The goal is to select the resources which best fit the user\u27s needs in specific activities. In particular, the thesis faces with the problem of metadata complexity and supports in the discovery of selection criteria which are unknown to the user. The metadata analysis consists of two approaches: visual and semantic analysis. The visual analysis involves the user as much as possible to let him discover the most suitable selection criteria. The semantic analysis supports in the browsing and selection of information resources taking into account the user\u27s knowledge which is properly formalized

    A multigranular object-oriented framework supporting spatio-temporal granularity conversions

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    Several application domains require handling spatio-temporal data. However, traditional Geographic Information Systems (GIS) and database models do not adequately support temporal aspects of spatial data. A crucial issue relates to the choice of the appropriate granularity. Unfortunately, while a formalisation of the concept of temporal granularity has been proposed and widely adopted, no consensus exists on the notion of spatial granularity. In this paper, we address these open problems, by proposing a formal definition of spatial granularity and by designing a spatio-temporal framework for the management of spatial and temporal information at different granularities. We present a spatio-temporal extension of the ODMG type system with specific types for defining multigranular spatio-temporal properties. Granularity conversion functions are introduced to obtain attributes values at different spatial and temporal granularities

    Modélisation des bases de données multidimensionnelles : analyse par fonctions d'agrégation multiples

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    Le résumé en français n'a pas été communiqué par l'auteur.Le résumé en anglais n'a pas été communiqué par l'auteur
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