SHõWA: A Self-healing Framework for Web-based Applications

The complexity of systems is considered an obstacle to the progress of the IT industry. Autonomic computing is presented as the alternative to cope with the growing complexity. It is a holistic approach, in which the systems are able to configure, heal, optimize, and protect by themselves. Web-based applications are an example of systems where the complexity is high. The number of components, their interoperability, and workload variations are factors that may lead to performance failures or unavailability scenarios. The occurrence of these scenarios affects the revenue and reputation of businesses that rely on these types of applications. In this article, we present a self-healing framework for Web-based applications (SHõWA). SHõWA is composed by several modules, which monitor the application, analyze the data to detect and pinpoint anomalies, and execute recovery actions autonomously. The monitoring is done by a small aspect-oriented programming agent. This agent does not require changes to the application source code and includes adaptive and selective algorithms to regulate the level of monitoring. The anomalies are detected and pinpointed by means of statistical correlation. The data analysis detects changes in the server response time and analyzes if those changes are correlated with the workload or are due to a performance anomaly. In the presence of per- formance anomalies, the data analysis pinpoints the anomaly. Upon the pinpointing of anomalies, SHõWA executes a recovery procedure. We also present a study about the detection and localization of anomalies, the accuracy of the data analysis, and the performance impact induced by SHõWA. Two benchmarking applications, exercised through dynamic workloads, and different types of anomaly were considered in the study. The results reveal that (1) the capacity of SHõWA to detect and pinpoint anomalies while the number of end users affected is low; (2) SHõWA was able to detect anomalies without raising any false alarm; and (3) SHõWA does not induce a significant performance overhead (throughput was affected in less than 1%, and the response time delay was no more than 2 milliseconds).

Comunicação estratégica digital. Otimização das estratégias comunicacionais através de novas plataformas sociais na web

Trabalho de Projeto apresentado para o cumprimento dos requisitos necessários à obtenção de grau de Mestre em Novos Media e Práticas Web

Intraferência : hacktivismo urbano digital, uma forma de preservação do património e promoção artística

Trabalho de Projecto apresentado para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Novos Média e Prácticas Web

Sistema para navegação web usando imagem e vídeo

Dissertação para obtenção do Grau de Mestre em Engenharia Informática

Características e implicações do conteúdo audiovisual na web

Trabalho de projecto apresentado para o cumprimento dos requisitos necessários à obtenção do grau de Mestre em Novos Média e Práticas Web

Web competitive intelligence methodology

Master’s Degree Dissertation

Post-MAPS: An interactive acquisition platform for gastroenterology

Post-MAPS is a web platform that collects gastroenterological exam data from several european hospital centers, to be used in future clinical studies and was developed in partnership with experts from the gastroenterological area and information technology (IT) technicians. However, although functional, this platform has some issues that are crucial for its functioning, and can render user interaction unpleasant and exhaustive. Accordingly, we proposed the development of a new web platform, in which we aimed for an improvement in terms of usability, data uni cation and interoperability. Therefore, it was necessary to identify and study different ways of acquiring clinical data and review some of the existing clinical databases in order to understand how they work and what type of data they store, as well as their impact and contribution to clinical knowledge. Closely linked to the data model is the ability to share data with other systems, so, we also studied the concept of interoperability and analyzed some of the most widely used international standards, such as DICOM, HL7 and openEHR. As one of the primary objectives of this project was to achieve a better level of usability, practices related to Human Computer-Interaction, such as requirement analysis, creation of conceptual models, prototyping, and evaluation were also studied. Before we began the development, we conducted an analysis of the previous platform, from a functional point of view, which allowed us to gather not only a list of architectural and interface issues, but also a list of improvement opportunities. It was also performed a small preliminary study in order to evaluate the platform's usability, where we were able to realize that perceived usability is different between users, and that, in some aspects, varies according to their location, age and years of experience. Based on the information gathered during the platform's analysis and in the conclusions of the preliminary study, a new platform was developed, prepared for all potential users, from the inexperienced to the most comfortable with technology. It presents major improvements in terms of usability, also providing several new features that simplify the users' work, improving their interaction with the system, making their experience more enjoyable.

Parallelization of web processing services on cloud computing: A case study of Geostatistical Methods

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Adding SOS Core & transactional profiles support to a web thin client

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Creating a GWT web application for the SOS standard enhanced profile

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Culture boundaries in semantic web

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Design and implementation of 3D buildings integration for a Webgl-Based Virtual Globe: a case study of Valencian Cadastre and Fide Building Mode

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

A Web based geospatial application for disaster preparedness in Uganda

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Hypermedia-based Web Services as System Integrators

As we move more closely to the practical concept of the Internet of Things and, our reliance on public and private APIs increases, web services and their related topics have become utterly crucial to the informatics community. However, the question about which style of web services would best solve a particular problem, can raise signi cant and multifarious debates. There can be found two implementation styles that highlight themselves: the RPC-oriented style represented by the SOAP protocol’s implementations and the hypermedia style, which is represented by the REST architectural style’s implementations. As we search examples of already established web services, we can nd a handful of robust and reliable public and private SOAP APIs, nevertheless, it seems that RESTful services are gaining popularity in the enterprise community. For the current generation of developers that work on informatics solutions, REST seems to represent a fundamental and straightforward alternative and even, a more deep-rooted approach than SOAP. But are they comparable? Do both approaches have each speci c best suitable scenarios? Such study is brie y carried out in the present document’s chapters, starting with the respective background study, following an analysis of the hypermedia approach and an instantiation of its architecture, in a particular case study applied in a BPM context.

Navegação web anónima e segura

A Web aproximou a humanidade dos seus pares a um nível nunca antes visto. Com esta facilidade veio também o cibercrime, o terrorismo e outros fenómenos característicos de uma sociedade tecnológica, plenamente informatizada e onde as fronteiras terrestres pouco importam na limitação dos agentes ativos, nocivos ou não, deste sistema. Recentemente descobriu-se que as grandes nações “vigiam” atentamente os seus cidadãos, desrespeitando qualquer limite moral e tecnológico, podendo escutar conversas telefónicas, monitorizar o envio e receção de e-mails, monitorizar o tráfego Web do cidadão através de poderosíssimos programas de monitorização e vigilância. Noutros cantos do globo, nações em tumulto ou envoltas num manto da censura perseguem os cidadãos negando-lhes o acesso à Web. Mais mundanamente, há pessoas que coagem e invadem a privacidade de conhecidos e familiares, vasculhando todos os cantos dos seus computadores e hábitos de navegação. Neste sentido, após o estudo das tecnologias que permitem a vigilância constante dos utilizadores da Web, foram analisadas soluções que permitem conceder algum anónimato e segurança no tráfego Web. Para suportar o presente estudo, foi efetuada uma análise das plataformas que permitem uma navegação anónima e segura e um estudo das tecnologias e programas com potencial de violação de privacidade e intrusão informática usados por nações de grande notoriedade. Este trabalho teve como objetivo principal analisar as tecnologias de monitorização e de vigilância informática identificando as tecnologias disponíveis, procurando encontrar potenciais soluções no sentido de investigar a possibilidade de desenvolver e disponibilizar uma ferramenta multimédia alicerçada em Linux e em LiveDVD (Sistema Operativo Linux que corre a partir do DVD sem necessidade de instalação). Foram integrados recursos no protótipo com o intuito de proporcionar ao utilizador uma forma ágil e leiga para navegar na Web de forma segura e anónima, a partir de um sistema operativo (SO) virtualizado e previamente ajustado para o âmbito anteriormente descrito. O protótipo foi testado e avaliado por um conjunto de cidadãos no sentido de aferir o seu potencial. Termina-se o documento com as conclusões e o trabalho a desenvolver futuramente.