The Adaptiveness in Stock Markets: Testing the Stylized Facts in the DAX 30

By testing a simple asset pricing model of heterogeneous agents to characterize the power-law behavior of the DAX 30 from 1975 to 2007, we provide supporting evidence on empirical findings that investors and fund managers use combinations of fixed and switching strategies based on fundamental and technical analysis when making investment decisions. By conducting econometric analysis via Monte Carlo simulations, we show that the autocorrelation patterns, the estimates of the power-law decay indices, (FI)GARCH parameters, and tail index of the model match closely the corresponding estimates for the DAX 30. A mechanism analysis based on the calibrated model provides further insights into the explanatory power of heterogeneous agent models.

Communication middleware for the future mobile internet

A evolução constante em novas tecnologias que providenciam suporte à forma como os nossos dispositivos se ligam, bem como a forma como utilizamos diferentes capacidades e serviços on-line, criou um conjunto sem precedentes de novos desafios que motivam o desenvolvimento de uma recente área de investigação, denominada de Internet Futura. Nesta nova área de investigação, novos aspectos arquiteturais estão ser desenvolvidos, os quais, através da re-estruturação de componentes nucleares subjacentesa que compõem a Internet, progride-a de uma forma capaz de não são fazer face a estes novos desafios, mas também de a preparar para os desafios de amanhã. Aspectos chave pertencendo a este conjunto de desafios são os ambientes de rede heterogéneos compostos por diferentes tipos de redes de acesso, a cada vez maior mudança do tráfego peer-to-peer (P2P) como o tipo de tráfego mais utilizado na Internet, a orquestração de cenários da Internet das Coisas (IoT) que exploram mecanismos de interação Maquinaa-Maquina (M2M), e a utilização de mechanismos centrados na informação (ICN). Esta tese apresenta uma nova arquitetura capaz de simultaneamente fazer face a estes desafios, evoluindo os procedimentos de conectividade e entidades envolvidas, através da adição de uma camada de middleware, que age como um mecanismo de gestão de controlo avançado. Este mecanismo de gestão de controlo aproxima as entidades de alto nível (tais como serviços, aplicações, entidades de gestão de mobilidade, operações de encaminhamento, etc.) com as componentes das camadas de baixo nível (por exemplo, camadas de ligação, sensores e atuadores), permitindo uma otimização conjunta dos procedimentos de ligação subjacentes. Os resultados obtidos não só sublinham a flexibilidade dos mecanismos que compoem a arquitetura, mas também a sua capacidade de providenciar aumentos de performance quando comparados com outras soluÇÕes de funcionamento especÍfico, enquanto permite um maior leque de cenáios e aplicações.

Architecture for real-time coordination of multiple autonomous mobile units

Interest on using teams of mobile robots has been growing, due to their potential to cooperate for diverse purposes, such as rescue, de-mining, surveillance or even games such as robotic soccer. These applications require a real-time middleware and wireless communication protocol that can support an efficient and timely fusion of the perception data from different robots as well as the development of coordinated behaviours. Coordinating several autonomous robots towards achieving a common goal is currently a topic of high interest, which can be found in many application domains. Despite these different application domains, the technical problem of building an infrastructure to support the integration of the distributed perception and subsequent coordinated action is similar. This problem becomes tougher with stronger system dynamics, e.g., when the robots move faster or interact with fast objects, leading to tighter real-time constraints. This thesis work addressed computing architectures and wireless communication protocols to support efficient information sharing and coordination strategies taking into account the real-time nature of robot activities. The thesis makes two main claims. Firstly, we claim that despite the use of a wireless communication protocol that includes arbitration mechanisms, the self-organization of the team communications in a dynamic round that also accounts for variable team membership, effectively reduces collisions within the team, independently of its current composition, significantly improving the quality of the communications. We will validate this claim in terms of packet losses and communication latency. We show how such self-organization of the communications can be achieved in an efficient way with the Reconfigurable and Adaptive TDMA protocol. Secondly, we claim that the development of distributed perception, cooperation and coordinated action for teams of mobile robots can be simplified by using a shared memory middleware that replicates in each cooperating robot all necessary remote data, the Real-Time Database (RTDB) middleware. These remote data copies, which are updated in the background by the selforganizing communications protocol, are extended with age information automatically computed by the middleware and are locally accessible through fast primitives. We validate our claim showing a parsimonious use of the communication medium, improved timing information with respect to the shared data and the simplicity of use and effectiveness of the proposed middleware shown in several use cases, reinforced with a reasonable impact in the Middle Size League of RoboCup.

Impact of antenna choices on the reliability of mobile broadband transmission at millimetre - wave frequencies

This paper deals with the impact of several antenna chices on the radio transmission performance within a cellular Mobile Broaband System (MBS) currently under research in Europe. Several antenna types are considered, namely switchable-beam antennas and adaptive antennas employing a phased array approach.

Adaptive transceiver - antenna techniques for mobile broadband communications at millimetre - wave frequencies

This paper is concerned with the implementation of a Mobile Broadband System, currently under research in Europe. We present a low-complexity, adaptive transceiver/antenna approach where simple, linear, phased arrays are adjusted under a transmission quality measurement provided by a decision-feedback equalizer. Several simulation results are presented and discussed.

Application of molecular tools for detection of plant viruses

Grapevine leafroll disease (GLRD) is one of the most important virus diseases of grapevines worldwide, causing major economical impact. The disease has a complex aetiology and currently eleven phloem-limited viruses, termed in general Grapevine leafroll-associated virus (GLRaVs), have been identified. Two of the GLRaVs, GLRaV-1 and GLRaV-3, are included in the European certification scheme of propagation material. However, the flawed notion that GLRaV-3 is more frequent than GLRaV-1 and that all other GLRaVs are possibly not as relevant for GLRD, has until now precluded the development of specific serological and molecular detection assays and limited the scope of molecular characterization of the viruses known to be associated with the disease. Hence, few studies have addressed the phylodynamics of GLRaVs or even characterized the genetic structure of their natural populations. This generalized lack of molecular information, in turn underlie the deficient capacity to detect the viruses. The phylogenetic analyses were conducted on the basis of the heat shock protein 70 homologue (HSP70h) and the coat protein (CP) genes for GLRaV-1 and the HSP70h, the heat shock protein 90 homologue (HSP90h) and the CP genes for GLRaV-5. The data obtained for GLRaV-1 contributed 83 new CP sequences. This information was combined with previous analysis by other authors and used for the production of new polyclonal IgG, capable of detecting CP variants from all the phylogroups observed. Successful testing of this new tool included tissue print immunoblotting (TPIB) and in situ immunoassay (ISIA). The data obtained for GLRaV-5, contributed 61 new CP and 28 new HSP90h gene sequences. Eight phylogenetic groups were identified on the basis of the CP. Characterization of the genetic structure of the isolates revealed a higher diversity than previously reported and allowed the identification of dominant virus variants. For both GLRaV-1 and GLRaV-5, the effect of vegetative propagation on the virus transmission dynamics was addressed.

LifeSpeeder: a web and mobile platform for events location

The use of smartphones and tablets as become almost banal in these days. Smartphones, besides serving their main purpose of making and receiving calls, come to be one of the main equipments to obtain information from the Internet, using the commonly installed browsers or through the use of dedicated applications. Furthermore, several other devices are also very frequent to the majority of the modern smartphones and tablets in the market (e.g., GPS - Global Positioning System). This devices give the current systems a very high potential of usage. One example of applicability, comes from the wish to find and navigate to events or activities which are or will soon be occurring near the user. The LifeSpeeder platform is one of the first applications in the mobile equipment market of applications which take into consideration exactly what we have just outlined, i.e., a mobile and desktop application which allows the users to locate events according with their preferences and to get help navigating to them. In this paper we briefly describe the LifeSpeeder's front and back-end. © 2014 Springer International Publishing.

virtX: ein Lehr- und Lernsystem für mobile Röntgengeräte zur Verbesserung der Ausbildung im Strahlenschutz

Hintergrund und Fragestellung: Die durch röntgentechnische Diagnoseverfahren in der Medizin entstehende Strahlenbelastung für Patient und Personal soll laut Strahlenschutzverordnung so gering wie möglich gehalten werden. Um dieses zu erreichen ist ein professioneller und bedachter Umgang mit den Röntgengeräten unabdingbar. Dieses Verhalten kann derzeit jedoch nur theoretisch vermittelt werden, da sich ein Üben mit realer Strahlung von selbst verbietet. Daher stellt sich die Frage wie man die Strahlenschutzausbildung durch eine verbesserte Vermittlung der komplexen Thematik unterstützen kann. Methoden: Das CBT-System (Computer Based Training) virtX, welches das Erlernen der korrekten Handhabung mobiler Röntgengeräte unterstützt, wurde um Aspekte aus dem Bereich des Strahlenschutzes erweitert. Es wurde eine prototypische Visualisierung der entstehenden Streustrahlung sowie die Darstellung des Nutzstrahlenganges integriert. Des Weiteren wurde die Berechnung und Anzeige der virtuellen Einfallsdosis für das durchstrahlte Volumen sowie für den Bereich des Bildverstärkers hinzugefügt. Für die Berechnung und Visualisierung all dieser Komponenten werden die in virtX parametrisierbaren C-Bogen-Einstellungen, z.B. Stellung der Blenden, Positionierung des Röntgengerätes zum durchstrahlten Volumen und Strahlenintensität, herangezogen. Das so erweiterte System wurde auf einem dreitägigen Kurs für OP-Personal mit über 120 Teilnehmern eingesetzt und auf der Basis von Fragebögen evaluiert. Ergebnisse: Von den Teilnehmern gaben 55 einen ausgefüllten Evaluations-Fragebogen ab (Responserate 82%). Das Durchschnittsalter der 39 weiblichen und 15 männlichen Teilnehmer (einer o.A.) lag bei 33±8 Jahren, die Berufserfahrung bei 9,37±7 Jahren. Die Erfahrung mit dem C-Bogen wurde von einem Teilnehmer (2%) mit „Keine oder bisher nur Einführung erhalten“, von acht Teilnehmern (14%) mit „bediene einen C-Bogen gelegentlich“ und von 46 (84%) mit „bediene einen C-Bogen regelmäßig“ angegeben. 45 (92%) der Teilnehmer gaben an, durch die Visualisierung der Streustrahlung etwas Neues zur Vermeidung unnötiger Strahlenbelastung dazugelernt zu haben. Schlussfolgerung: Trotz einer bislang nur prototypischen Visualisierung der Streustrahlung können mit virtX zentrale Aspekte und Verhaltensweisen zur Vermeidung unnötiger Strahlenbelastung erfolgreich vermittelt werden und so Lücken der traditionellen Strahlenschutzausbildung geschlossen werden.

Using Mobile Learning Games for Delivery Purposes in Humanities

Games and applications with gamified elements have been used in teaching and learning widely. Gamified applications attract the interest of students and teachers because they assist them to achieve their cognitive and pedagogical purposes. This paper describes a study that explores the use of a gamified learning application designed to introduce students at key stages 3 and 4 (ages 14-15) to ancient Greek Philosophy. The study involves 3 tests and 3 different groups of students and aimed to explore if the application improves students' knowledge and understanding and to compare different styles of subject delivering. This paper presents and discusses in details the results of the first test.

Handling mobility on a QoS-Aware servicebased framework for mobile systems

Mobile applications are becoming increasingly more complex and making heavier demands on local system resources. Moreover, mobile systems are nowadays more open, allowing users to add more and more applications, including third-party developed ones. In this perspective, it is increasingly expected that users will want to execute in their devices applications which supersede currently available resources. It is therefore important to provide frameworks which allow applications to benefit from resources available on other nodes, capable of migrating some or all of its services to other nodes, depending on the user needs. These requirements are even more stringent when users want to execute Quality of Service (QoS) aware applications, such as voice or video. The required resources to guarantee the QoS levels demanded by an application can vary with time, and consequently, applications should be able to reconfigure themselves. This paper proposes a QoS-aware service-based framework able to support distributed, migration-capable, QoS-enabled applications on top of the Android Operating system.

Application of fractional algorithms in the control of a robotic bird

In this paper, it is studied the dynamics of the robotic bird in terms of time response and robustness. It is analyzed the wing angle of attack and the velocity of the bird, the tail influence, the gliding flight and the flapping flight. The results are positive for the construction of flying robots. The development of computational simulation based on the dynamic of the robotic bird should allow testing strategies and different algorithms of control such as integer and fractional controllers.

Mining social individuals movements and friends based on mobile devices

Trabalho de Projeto realizado para obtenção do grau de Mestre em Engenharia Informática e de Computadores

Plano de Negócio para a aplicação mobile Nutri Consult

Trabalho de projeto apresentado à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Publicidade e Marketing.

App mobile “My Corine de Farme”

Trabalho de projeto apresentado à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Publicidade e Marketing.

Application of Visual-Inertial SLAM for 3D Mapping of Underground Environments

The underground scenarios are one of the most challenging environments for accurate and precise 3d mapping where hostile conditions like absence of Global Positioning Systems, extreme lighting variations and geometrically smooth surfaces may be expected. So far, the state-of-the-art methods in underground modelling remain restricted to environments in which pronounced geometric features are abundant. This limitation is a consequence of the scan matching algorithms used to solve the localization and registration problems. This paper contributes to the expansion of the modelling capabilities to structures characterized by uniform geometry and smooth surfaces, as is the case of road and train tunnels. To achieve that, we combine some state of the art techniques from mobile robotics, and propose a method for 6DOF platform positioning in such scenarios, that is latter used for the environment modelling. A visual monocular Simultaneous Localization and Mapping (MonoSLAM) approach based on the Extended Kalman Filter (EKF), complemented by the introduction of inertial measurements in the prediction step, allows our system to localize himself over long distances, using exclusively sensors carried on board a mobile platform. By feeding the Extended Kalman Filter with inertial data we were able to overcome the major problem related with MonoSLAM implementations, known as scale factor ambiguity. Despite extreme lighting variations, reliable visual features were extracted through the SIFT algorithm, and inserted directly in the EKF mechanism according to the Inverse Depth Parametrization. Through the 1-Point RANSAC (Random Sample Consensus) wrong frame-to-frame feature matches were rejected. The developed method was tested based on a dataset acquired inside a road tunnel and the navigation results compared with a ground truth obtained by post-processing a high grade Inertial Navigation System and L1/L2 RTK-GPS measurements acquired outside the tunnel. Results from the localization strategy are presented and analyzed.