Um sistema de informação espaço-temporal para objectos móveis

Dissertação de mestrado integrado em Engenharia de ComunicaçõesA grande evolução tecnológica tanto dos Sistemas de Informação Geográfica (SIG) bem como das tecnologias de localização (GPS, WI-FI, RFID) contribuíram para um significativo aumento da recolha de dados espaciais. Devido a esta proliferação e às grandes quantidades de dados que são recolhidos, são necessárias bases de dados e mecanismos apropriados para o seu armazenamento e sua respectiva análise. No passado, o desenho de sistemas de informação para objectos móveis basearam-se muitas vezes em abordagens (aplicações) restritas a tecnologias de localização específicas, levando a um vasto leque de modelos de dados, modelos de base de dados e respectivas funcionalidades. Para superar esta proliferação de modelos, este projecto propõe um sistema de informação espaço-temporal independente do domínio de aplicação, e com o intuito de se abstrair da tecnologia de posicionamento utilizada para a recolha de dados. Este sistema de informação espaço-temporal visa o desenvolvimento de um sistema de armazenamento, análise e visualização de dados sobre objectos móveis capazes de representar e armazenar dados com características espaciais e de realizar análises sobre os mesmos. Este sistema é intitulado STAR e integra três componentes principais, as bases de dados espaçotemporais, os SIG e os dados espaço-temporais. A base de dados espaço-temporal desenhada permite o armazenamento dos dados espaço-temporais bem como o armazenamento da geometria do espaço no qual ocorre o movimento. Esta geometria é representada por pontos, linhas e/ou polígonos. Os SIG auxiliam os processos de análise e visualizações de dados. Os dados espaço-temporais são intitulados neste projecto de objectos móveis, podendo o movimento dos mesmos ser analisado no STAR. Os resultados alcançados são promissores na demonstração de como o sistema é capaz de armazenar dados de posicionamento com formatos diferentes, e na aplicação de análises, visualizações e representações sobre os mesmos.The huge technological evolution of both the Geographic Information Systems (GIS) as well as location technologies (GPS, Wi-Fi, RFID) contributes to a large increase in spatial data collection. Because of this proliferation and to the large amounts of data that are collected, databases and appropriate mechanisms for their storage and their analysis are necessary. In the past, the design of information systems for moving objects was often based on approaches (applications) restricted to specific location technologies, leading to a wide range of data models, database models and functionalities. To overcome this proliferation of models, this project proposes a spatio-temporal information system that is independent of the application domain and that abstract the positioning technology used for data collection. This spatio-temporal information system aims the development of a storage system with data analysis and visualization mechanism for moving objects that can represent and store data with spatial characteristics and perform spatial analysis on them. This system is named STAR and incorporates three main components, spatio-temporal databases, GIS and spatio-temporal data. The designed spatio-temporal database enables the storage of the spatio-temporal data and the geometry of the space in which the movement occurs. This geometry is represented by points, lines and/or polygons. The GIS help the processes of analysis and visualization of data. The spatio-temporal data in this project are entitled to moving objects, their movement can be analysed in STAR. The results obtained so far are promising in demonstrating how the system is capable of storing positioning data with different formats, and in applying analysis, visualizations and different representations of the analysed data

Semantic Trajectories: Mobility Data Computation and Annotation

With the large-scale adoption of GPS equipped mobile sensing devices, positional data generated by moving objects (e.g., vehicles, people, animals) are being easily collected. Such data are typically modeled as streams of spatio-temporal (x,y,t) points, called ''trajectories''. In recent years trajectory management research has progressed significantly towards efficient storage and indexing techniques, as well as suitable knowledge discovery. These works focused on the geometric aspect of the raw mobility data. We are now witnessing a growing demand in several application sectors (e.g., from shipment tracking to geo-social networks) on understanding the {\it semantic'' behavior of moving objects. Semantic behavior refers to the use of semantic abstractions of the raw mobility data, including not only geometric patterns but also knowledge extracted jointly from the mobility data and the underlying geographic and application domains information. The core contribution of this paper lies in a ''Semantic Model'' and a ''Computation and Annotation Platform'' for developing a semantic approach that progressively transforms the raw mobility data into semantic trajectories enriched with annotations and segmentations. We also analyze a number of experiments we did with semantic trajectories in different domains

Metamodelisation to support Test and Evolution

Legacy software systems correspond to the wealth of the companies. They often exist for dozens of years and concentrate a big part of the company knowledge, its business rules or its savoir-faire. Requirements to which these systems answer have evolved with time, as well as the used technologies leading to modications. These mo-dications occurring after the software delivery, they are considered maintenance. They correspond to more than 80% of the software li-fecycle and its cost. Maintaining a software system is a complex and useful activity that deserves to o be anticipated from the design activity. Remodularisation phases may be useful to reduce complexity massed from successive evolutions and to provide new strong basis for future evolutions. Work presented in this manuscript answers to a unique target : Designing systems of good quality, easily maintainable and managing their evolutions. Quality can be ensured and measured from dierent ways. In this document, I only focus on tests. Tests enable developers to identify and locate errors or check after an evolution that unchanged parts are not impacted. Finally, software artefacts do not independently evolve. The evolution of one of them may have consequences on one or several others. In this document, two types of software are considered chains of model transformations or traditional programs. Thus, transformation chains are not seen as a way to generate code from models via transformations. They are considered software system by them selves that would need to be later maintained and to make evolve. Results presented in this document may be summarised as such : Proposal of a new transformation type localized transformations introducing better reusability, modularity and exibility in transformation chains. Adaptations in designing and building chains are thus needed