Creating and optimizing client-server applications on mobile devices

Mobile devices are embedded systems with very limited capacities that need to be considered when developing a client-server application, mainly due to technical, ergonomic and economic implications to the mobile user. With the increasing popularity of mobile computing, many developers have faced problems due to low performance of devices. In this paper, we discuss how to optimize and create client-server applications for in wireless/mobile environments, presenting techniques to improve overall performance

Controlo multi-drones com suporte a missões autónomas

Recent advancements regarding miniaturization of sensors and instruments, as well as the reduction of their cost, promoted a growth in the usage of drones in an increasingly wide range of scenarios such as search and rescue, agriculture and environmental monitoring. However, most currently available mechanisms for drone control still require a constantly aware pilot, thus limiting the convenience of executing complex missions, especially when more than one drone is involved. Major drone and flight controller manufacturers, however, are displaying an increasing interest in providing programming interfaces and development kits that enable the execution of basic autonomous flight, including commands such as taking off, landing and waypoint navigation. These interfaces facilitate the integration of said drones in platforms that aim to abstract manual control from their users. This dissertation proposes a complete and modular solution for controlling one or more drones, enabling an inexperienced user to plan, execute and monitor complex missions with various participants, also implementing the required functionality for the collaboration of a set of drones in the execution of such missions. The proposed solution consists in a modular platform composed of loosely coupled components. Each component is individually designed to handle specific tasks such as flight control hardware interfacing, telemetry acquisition and storage, and mission planning. Components accomplish their interactions by using message brokers, while user interaction is achieved through intuitive web and mobile applications. The functionality of the solution is evaluated through the completion of four experiments, which represent typical scenarios where the control platform may be used. These experiments cover both single-drone and multi-drone functionality, with the first two covering tasks carried out by one drone, while the last two represent scenarios where multiple drones collaborate towards a common goal.Com os avanços recentes na redução do tamanho dos sensores e instrumentos, assim como na redução de custos dos mesmos, a utilização de drones é cada vez mais comum e abrange um número cada vez superior de casos de utilização tais como missões de procura e resgate, agricultura e monitorização ambiental. Contudo, a maior parte das alternativas existentes para controlo ainda exigem a atenção constante de um piloto, limitando a conveniência da execução de missões complexas, sobretudo quando nelas participa mais que um drone. Os principais fabricantes de drones e controladores de vôo, no entanto, disponibilizam cada vez mais frequentemente interfaces para a execução de funções básicas de vôo autónomo, como por exemplo a descolagem, aterragem e a navegação baseada em coordenadas geográficas. A existência cada vez mais comum destas interfaces permite a integração de drones em plataformas que têm como objectivo a abstração do seu controlo directo. Esta dissertação propõe uma solução modular completa para controlo de um ou mais drones, permitindo a um utilizador inexperiente o planeamento, execução e monitorização de missões complexas com vários participantes, implementando também a funcionalidade necessária para a colaboração de vários drones na execução de uma missão. A solução proposta consiste numa plataforma modular, composta por componentes que são executados de forma independente. Cada componente é individualmente desenvolvido para executar tarefas específicas como a comunicação com o controlador de vôo, a aquisição e armazenamento de telemetria e o planeamento de missões. Os componentes realizam as suas interações através da utilização de filas de mensagens, enquanto a interação com o utilizador é realizada através de aplicações intuitivas web ou mobile. As funcionalidades da solução proposta são avaliadas através da execução de quatro testes distintos, que representam cenários típicos em que a plataforma de controlo pode ser usada. Estes testes cobrem a utilização de um ou mais drones, sendo que as duas primeiras tarefas são executadas apenas por um drone e as últimas duas representam cenários em que vários drones colaboram para alcançar um objectivo comum.Apoio financeiro do POCTI no âmbito do III Quadro Comunitário de Apoio. Apoio financeiro da FCT e do FSE no âmbito do III Quadro Comunitário de Apoio.Mestrado em Engenharia de Computadores e Telemátic

Distributed Agent-Based Online Auction System

This paper concerns the design and development of a distributed agent-based online system for English auctions. The proposed system is composed of two parts: an Agent-based Auction Server and a Web-based Graphical User Interface. The first part of our work brought about the advantages introduced by the multi-agent systems technology to the high-level of abstraction, modularity and performance of the server architecture and its implementation. On the server side, bids submitted by auction participants are handled by a hierarchical organization of agents that can be efficiently distributed on a computer network. This approach avoids the bottlenecks of bid processing that might occur during periods of heavy bidding, like for example snipping. We present experimental results that show a significant improvement of the server throughput compared with the architecture where a single auction manager agent is used for coordinating the participants for each active auction that is registered with the server. The second part of our work involved analysis of external functionalities, implementation and usability of a prototype online auction system that incorporates the Agent-based Auction Server. Our solution is outlined in terms of information flow management and its relation to the functionalities of the system. The main outcome of this part of the work is a clean specification of the information exchanges between the agent and non-agent software components of the system. Special attention is also given to the interoperability, understood here as successful integration of the different data communication protocols and software technologies that we employed for the implementation of the system

Pernova: A travel industry business plan

The travel and tourism industries are today facing unprecedented challenges in coping with emerging technology paradigms. Consequently, reengineering traditional travel business models is necessary. Internet technologies coupled with increasingly complex software applications and information structures are distracting travel companies from the strategic elements of providing values to travelers

Carbook: A Platform for Mobile Automotive Services

Wireless mobile technologies have triggered a rapid development of secondary network technologies. One such prominent field of technology is interoperability for consumer devices. This field is mostly based on XML and Web Services and it includes technologies such as Universal Plug-and-Play, open media container formats, open codecs and Rich Internet Application technologies for mobile devices. Automotive field has been relatively slow and conservative in embracing these new Internet technologies. This is about to change as European Union and other substantial players are pressing forward with the safety and environmental technologies in cars. These technologies depend heavily on wireless Internet connectivity. As part of this thesis work, I have played a central role in defining the core concept of a distributed framework for mobile automotive services, Carbook System. I have also outlined the first phase of a shared research environment, Carlab, for these kinds of services. Carlab is used to demonstrate different technologies in accordance to Elektrobit’s vision for the future automotive Internet services. Carbook System will be implemented incrementally jointly with the continuation of the Carlab implementation. In this master of science thesis I have mapped and evaluated the essential technologies and created a preliminary outline for Carbook System and a set of services. The first phase Carlab network topology and emulation of different domains in Carbook System are also drafted in this thesis work

Design and Evaluation of Web-Based Economic Indicators: A Big Data Analysis Approach

Tesis por compendio[ES] En la Era Digital, el creciente uso de Internet y de dispositivos digitales está transformando completamente la forma de interactuar en el contexto económico y social. Miles de personas, empresas y organismos públicos utilizan Internet en sus actividades diarias, generando de este modo una enorme cantidad de datos actualizados ("Big Data") accesibles principalmente a través de la World Wide Web (WWW), que se ha convertido en el mayor repositorio de información del mundo. Estas huellas digitales se pueden rastrear y, si se procesan y analizan de manera apropiada, podrían ayudar a monitorizar en tiempo real una infinidad de variables económicas. En este contexto, el objetivo principal de esta tesis doctoral es generar indicadores económicos, basados en datos web, que sean capaces de proveer regularmente de predicciones a corto plazo ("nowcasting") sobre varias actividades empresariales que son fundamentales para el crecimiento y desarrollo de las economías. Concretamente, tres indicadores económicos basados en la web han sido diseñados y evaluados: en primer lugar, un indicador de orientación exportadora, basado en un modelo que predice si una empresa es exportadora; en segundo lugar, un indicador de adopción de comercio electrónico, basado en un modelo que predice si una empresa ofrece la posibilidad de venta online; y en tercer lugar, un indicador de supervivencia empresarial, basado en dos modelos que indican la probabilidad de supervivencia de una empresa y su tasa de riesgo. Para crear estos indicadores, se han descargado una diversidad de datos de sitios web corporativos de forma manual y automática, que posteriormente se han procesado y analizado con técnicas de análisis Big Data. Los resultados muestran que los datos web seleccionados están altamente relacionados con las variables económicas objeto de estudio, y que los indicadores basados en la web que se han diseñado en esta tesis capturan en un alto grado los valores reales de dichas variables económicas, siendo por tanto válidos para su uso por parte del mundo académico, de las empresas y de los decisores políticos. Además, la naturaleza online y digital de los indicadores basados en la web hace posible proveer regularmente y de forma barata de predicciones a corto plazo. Así, estos indicadores son ventajosos con respecto a los indicadores tradicionales. Esta tesis doctoral ha contribuido a generar conocimiento sobre la viabilidad de producir indicadores económicos con datos online procedentes de sitios web corporativos. Los indicadores que se han diseñado pretenden contribuir a la modernización en la producción de estadísticas oficiales, así como ayudar a los decisores políticos y los gerentes de empresas a tomar decisiones informadas más rápidamente.[CA] A l'Era Digital, el creixent ús d'Internet i dels dispositius digitals està transformant completament la forma d'interactuar al context econòmic i social. Milers de persones, empreses i organismes públics utilitzen Internet a les seues activitats diàries, generant d'aquesta forma una enorme quantitat de dades actualitzades ("Big Data") accessibles principalment mitjançant la World Wide Web (WWW), que s'ha convertit en el major repositori d'informació del món. Aquestes empremtes digitals poden rastrejar-se i, si se processen i analitzen de forma apropiada, podrien ajudar a monitoritzar en temps real una infinitat de variables econòmiques. En aquest context, l'objectiu principal d'aquesta tesi doctoral és generar indicadors econòmics, basats en dades web, que siguen capaços de proveïr regularment de prediccions a curt termini ("nowcasting") sobre diverses activitats empresarials que són fonamentals per al creixement i desenvolupament de les economies. Concretament, tres indicadors econòmics basats en la web han sigut dissenyats i avaluats: en primer lloc, un indicador d'orientació exportadora, basat en un model que prediu si una empresa és exportadora; en segon lloc, un indicador d'adopció de comerç electrònic, basat en un model que prediu si una empresa ofereix la possibilitat de venda online; i en tercer lloc, un indicador de supervivència empresarial, basat en dos models que indiquen la probabilitat de supervivència d'una empresa i la seua tasa de risc. Per a crear aquestos indicadors, s'han descarregat una diversitat de dades de llocs web corporatius de forma manual i automàtica, que posteriorment s'han analitzat i processat amb tècniques d'anàlisi Big Data. Els resultats mostren que les dades web seleccionades estan altament relacionades amb les variables econòmiques objecte d'estudi, i que els indicadors basats en la web que s'han dissenyat en aquesta tesi capturen en un alt grau els valors reals d'aquestes variables econòmiques, sent per tant vàlids per al seu ús per part del món acadèmic, de les empreses i dels decisors polítics. A més, la naturalesa online i digital dels indicadors basats en la web fa possible proveïr regularment i de forma barata de prediccions a curt termini. D'aquesta forma, són avantatjosos en comparació als indicadors tradicionals. Aquesta tesi doctoral ha contribuït a generar coneixement sobre la viabilitat de produïr indicadors econòmics amb dades online procedents de llocs web corporatius. Els indicadors que s'han dissenyat pretenen contribuïr a la modernització en la producció d'estadístiques oficials, així com ajudar als decisors polítics i als gerents d'empreses a prendre decisions informades més ràpidament.[EN] In the Digital Era, the increasing use of the Internet and digital devices is completely transforming the way of interacting in the economic and social framework. Myriad individuals, companies and public organizations use the Internet for their daily activities, generating a stream of fresh data ("Big Data") principally accessible through the World Wide Web (WWW), which has become the largest repository of information in the world. These digital footprints can be tracked and, if properly processed and analyzed, could help to monitor in real time a wide range of economic variables. In this context, the main goal of this PhD thesis is to generate economic indicators, based on web data, which are able to provide regular, short-term predictions ("nowcasting") about some business activities that are basic for the growth and development of an economy. Concretely, three web-based economic indicators have been designed and evaluated: first, an indicator of firms' export orientation, which is based on a model that predicts if a firm is an exporter; second, an indicator of firms' engagement in e-commerce, which is based on a model that predicts if a firm offers e-commerce facilities in its website; and third, an indicator of firms' survival, which is based on two models that indicate the probability of survival of a firm and its hazard rate. To build these indicators, a variety of data from corporate websites have been retrieved manually and automatically, and subsequently have been processed and analyzed with Big Data analysis techniques. Results show that the selected web data are highly related to the economic variables under study, and the web-based indicators designed in this thesis are capturing to a great extent their real values, thus being valid for their use by the academia, firms and policy-makers. Additionally, the digital and online nature of web-based indicators makes it possible to provide timely, inexpensive predictions about the economy. This way, they are advantageous with respect to traditional indicators. This PhD thesis has contributed to generating knowledge about the viability of producing economic indicators with data coming from corporate websites. The indicators that have been designed are expected to contribute to the modernization of official statistics and to help in making earlier, more informed decisions to policy-makers and business managers.Blázquez Soriano, MD. (2019). Design and Evaluation of Web-Based Economic Indicators: A Big Data Analysis Approach [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/116836TESISCompendi

Semantic discovery and reuse of business process patterns

Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse