Hierarchical Reinforcement Learning in Behavior and the Brain

Dissertation presented to obtain the Ph.D degree in Biology, NeuroscienceReinforcement learning (RL) has provided key insights to the neurobiology of learning and decision making. The pivotal nding is that the phasic activity of dopaminergic cells in the ventral tegmental area during learning conforms to a reward prediction error (RPE), as speci ed in the temporal-di erence learning algorithm (TD). This has provided insights to conditioning, the distinction between habitual and goal-directed behavior, working memory, cognitive control and error monitoring. It has also advanced the understanding of cognitive de cits in Parkinson's disease, depression, ADHD and of personality traits such as impulsivity.(...

Using FTT-CAN to the Flexible Control of Bus Redundancy and Bandwidth Usage

DETIController Area Network (CAN) is a popular and very well-known bus system, both in academia and in industry, initially targeted to automotive applications as a single digital bus to replace the wiring that were growing complexity, weight and cost with the advent of new automotive appliances. However, requirements have evolved and CAN’s dependability and bandwidth limitations led to the emergence of alternative networks such as FlexRay and TTP/C. Nevertheless, we believe that it is possible to improve CAN so it could fulfill contemporary requirements. This paper proposes the use of Flexible Time-Triggered CAN (FTT-CAN) to increase the available bandwidth while providing fault tolerance in CAN based systems with multiple buses. The architecture and flexibility of FTT based systems enables a tight yet flexible control of redundancy and bandwidth usage without increasing the complexity of the nodes. In this novel solution, a FTT-CAN Master controls the dispatching of messages among a set of independent buses. The Master can react online to bus failures switching the transmission of critical messages to a non-faulty bus, always keeping a predetermined redundancy level

Liquefação de solos à luz da mecânica aplicada

Há uma crescente convicção da vantagem em encarar o fenómeno de liquefação de solos como passível de ser considerado como um comportamento elasto-plástico que é modelável a partir de conceitos baseados em estados críticos, enquanto se reconhece que pode ocorrer num largo espectro de materiais e condições. Estes assuntos são desenvolvidos neste artigo, atendendo a que as ferramentas de estados críticos têm sido estendidas a outros materiais para além das areias. Esta abordagem integra o conhecimento da influência que a micromecânica das partículas e dos seus contactos tem no comportamento dos solos, e tem em consideração os efeitos da quebra progressiva das partículas e as alterações do grau de uniformidade dos solos no decurso do carregamento. Os objetivos do dimensionamento com base em comportamento são apresentados à luz de ensaios em laboratório e de campo que permitem identificar o risco de se espoletar o fenómeno de liquefação, tanto em condições cíclicas, como estáticas. Também será discutida a forma como os resultados desses ensaios podem ser interpretados para se poder prever o fenómeno, à luz de uma abordagem mecânica global.The advantage of looking at soil liquefaction as an elasto-plastic mechanical behaviour that is well modelled by critical state concepts is well accepted, while recognising that it takes places in a wide range of materials and conditions. These issues are outlined in this paper, as the critical state framework has now been extended to other materials apart from sands. This approach integrates the knowledge of the influence of the micromechanics of particles and their contacts on the observed behaviour, and takes into account the effects of continued particle breakage and change in uniformity. The objectives of performance-based design are presented in the light of laboratory and field tests that permit to identify the risk of triggering both cyclic and static liquefaction. It is also discussed how those tests can be performed and their results interpreted to predict these phenomena, under a global mechanical modelling approach

Social Model—Innovation and Behavioural Intervention as a Public Policy of Action within an Oncology and Loneliness Scope

: The article presents concepts and the Public Health Policy University of Lisbon Lab project to answer questions about the macro-environment of cancer and loneliness. Although the biomedical model has considered the disease’s general symptoms, it takes a holistic approach to incorporate several other circumstances that influence health. Emotional, social, psychological, and economic factors mirror influencing layers that affect wellness. Portugal follows Europe’s tendency and simultaneously reflects its reality. Governmental internal policies, amplified by regulations, improve disease prevention and treatment. Nevertheless, it focuses on the general population instead of on the individual. Once cancer, one of the leading causes of global death, is perceived as an isolated incident, we believe macro-environmental circumstances, and not only biological ones, must be considered. Furthermore, cancer in the elderly intensifies solicitude, and expanded policies and actions demand individual health determinants. In the Portuguese Public Health Policy, we started a collaborative Oncology, Human Kinetics, and Public Health Policy project. This is the first project of the Public Health Policy Lab from the Institute of Social and Political Sciences of the University of Lisbon. Based on a brief review of two research projects on improving cancer patients’ health, we promote micro-organisational projects to deal with the social phenomena of loneliness, physical activity, and lifestyle. As a sequence of the well-known social determinants, we endorse political determinants as the basis for public health. The latest worldwide governmental trend is to create public labs as an innovation of political policymaking. Throughout this reflection, the need for a new rational approach specially designed for a social model is considered.info:eu-repo/semantics/publishedVersio

Flexible Bus Media Redundancy

DETIThis paper proposes a flexible approach to bus media redundancy in Controller Area Network (CAN) fieldbuses, both to improve the bandwidth by transmitting different traffic in different channels or to promote redundancy by transmitting the same message in more than one channel. Specifically the proposed solution is discussed in the context of Flexible Time-Triggered protocol over CAN (FTTCAN) and inherits the online scheduling flexibility of FTTCAN, enabling on-the-fly modifications of the traffic conveyed in the replicated buses. Flexible bus media redundancy is useful to fulfill application requirements in terms of additional bandwidth or to react to bus failures leading the system to a degraded operational mode, without compromising safety. The arguments for and against flexible bus media redundancy in the context of FTT-CAN are also discussed in detail

Controller Area Network

Controller Area Network (CAN) is a popular and very well-known bus system, both in academia and in industry. CAN protocol was introduced in the mid eighties by Robert Bosch GmbH [7] and it was internationally standardized in 1993 as ISO 11898-1 [24]. It was initially designed to distributed automotive control systems, as a single digital bus to replace traditional point-to-point cables that were growing in complexity, weight and cost with the introduction of new electrical and electronic systems. Nowadays CAN is still used extensively in automotive applications, with an excess of 400 million CAN enabled microcontrollers manufactured each year [14]. The widespread and successful use of CAN in the automotive industry, the low cost asso- ciated with high volume production of controllers and CAN's inherent technical merit, have driven to CAN adoption in other application domains such as: industrial communications, medical equipment, machine tool, robotics and in distributed embedded systems in general. CAN provides two layers of the stack of the Open Systems Interconnection (OSI) reference model: the physical layer and the data link layer. Optionally, it could also provide an additional application layer, not included on the CAN standard. Notice that CAN physical layer was not dened in Bosch original specication, only the data link layer was dened. However, the CAN ISO specication lled this gap and the physical layer was then fully specied. CAN is a message-oriented transmission protocol, i.e., it denes message contents rather than nodes and node addresses. Every message has an associated message identier, which is unique within the whole network, dening both the content and the priority of the message. Transmission rates are dened up to 1 Mbps. The large installed base of CAN nodes with low failure rates over almost two decades, led to the use of CAN in some critical applications such as Anti-locking Brake Systems (ABS) and Electronic Stability Program (ESP) in cars. In parallel with the wide dissemination of CAN in industry, the academia also devoted a large eort to CAN analysis and research, making CAN one of the must studied eldbuses. That is why a large number of books or book chapters describing CAN were published. The rst CAN book, written in French by D. Paret, was published in 1997 and presents the CAN basics [32]. More implementation oriented approaches, including CAN node implementation and application examples, can be found in Lorenz [28] and in Etschberger [16], while more compact descriptions of CAN can be found in [11] and in some chapters of [31]. Despite its success story, CAN application designers would be happier if CAN could be made faster, cover longer distances, be more deterministic and more dependable [34]. Over the years, several protocols based in CAN were presented, taking advantage of some CAN properties and trying to improve some known CAN drawbacks. This chapter, besides presenting an overview of CAN, describes also some other relevant higher level protocols based on CAN, such as CANopen [13], DeviceNet [6], FTT-CAN [1] and TTCAN [25]

Web competitive intelligence methodology

Master’s Degree DissertationThe present dissertation covers academic concerns in disruptive change that causes value displacements in today’s competitive economic environment. To enhance survival capabilities organizations are increasing efforts in more untraditional business value assets such intellectual capital and competitive intelligence. Dynamic capabilities, a recent strategy theory states that companies have to develop adaptive capabilities to survive disruptive change and increase competitive advantage in incremental change phases. Taking advantage of the large amount of information in the World Wide Web it is propose a methodology to develop applications to gather, filter and analyze web data and turn it into usable intelligence (WeCIM). In order to enhance information search and management quality it is proposed the use of ontologies that allow computers to “understand” particular knowledge domains. Two case studies were conducted with satisfactory results. Two software prototypes were developed according to the proposed methodology. It is suggested that even a bigger step can be made. Not only the success of the methodology was proved but also common software architecture elements are present which suggests that a solid base can be design for different field applications based on web competitive intelligence tools