O papel da Wason Selection Task na avaliação da psicopatia

O estudo da Psicopatia tem conquistado, nos anos mais recentes, um grande relevo dentro da investigação científica, estando sempre a serem feitos novos estudos que têm como objetivo a deteção eficiente da psicopatia. Portugal não é diferente. No entanto, apesar de já existirem investigações na área da psicopatia, os estudos e os instrumentos devidamente aferidos para a sua avaliação na população portuguesa ainda são escassos, pelo que se torna necessário continuar a trabalhar e a evoluir nesta área. É neste contexto que surge a ideia da aplicação da Wason Selection Task em conjunto com a PCL:SV na população portuguesa. Acredita-se que a Wason Selection Task poderá complementar a aplicação da PCL:SV, pois esta é um teste de lógica, onde os resultados obtidos são mais fidedignos, na medida de em que há menor permeabilidade a fenómenos de desejabilidade social.

Do challenge, task experience or computer familiarity influence the learning of historical chronology from virtual environments in 8–9 year old children?

Studies examined the potential use of Virtual Environments (VEs) in teaching historical chronology to 127 children of primary school age (8–9 years). The use of passive fly-through VEs had been found, in an earlier study, to be disadvantageous with this age group when tested for their subsequent ability to place displayed sequential events in correct chronological order. All VEs in the present studies included active challenge, previously shown to enhance learning in older participants. Primary school children in the UK (all frequent computer users) were tested using UK historical materials, but no significant effect was found between three conditions (Paper, PowerPoint and VE) with minimal pre-training. However, excellent (error free) learning occurred when children were allowed greater exploration prior to training in the VE. In Ukraine, with children having much less computer familiarity, training in a VE (depicting Ukrainian history) produced better learning compared to PowerPoint, but no better than in a Paper condition. The results confirmed the benefit of using challenge in a VE with primary age children, but only with adequate prior familiarisation with the medium. Familiarity may reduce working memory load and increase children’s spatial memory capacity for acquiring sequential temporal-spatial information from virtual displays. Keywords: timeline, chronographics

Comparing segmentation strategies for efficient video passage retrieval

We compare the effect of different text segmentation strategies on speech based passage retrieval of video. Passage retrieval has mainly been studied to improve document retrieval and to enable question answering. In these domains best results were obtained using passages defined by the paragraph structure of the source documents or by using arbitrary overlapping passages. For the retrieval of relevant passages in a video, using speech transcripts, no author defined segmentation is available. We compare retrieval results from 4 different types of segments based on the speech channel of the video: fixed length segments, a sliding window, semantically coherent segments and prosodic segments. We evaluated the methods on the corpus of the MediaEval 2011 Rich Speech Retrieval task. Our main conclusion is that the retrieval results highly depend on the right choice for the segment length. However, results using the segmentation into semantically coherent parts depend much less on the segment length. Especially, the quality of fixed length and sliding window segmentation drops fast when the segment length increases, while quality of the semantically coherent segments is much more stable. Thus, if coherent segments are defined, longer segments can be used and consequently less segments have to be considered at retrieval time.

Language evolution and recursion : an empirical investigation of human hierarchical processing

Tese de doutoramento, Ciências Biomédicas (Neurociências), Universidade de Lisboa, Faculdade de Medicina, 2014

O desenvolvimento do pensamento algébrico de alunos do 4º ano de escolaridade : uma experiência de ensino

Tese de doutoramento, Educação (Didática da Matemática), Universidade de Lisboa, Instituto de Educação, 2014

Contigo eu posso : caminhos da aprendizagem de uma menina com Síndrome de Down

Dissertação de mestrado, Ciências da Educação (Área de especialização em Educação Intercultural), Universidade de Lisboa. Instituto de Educação, 2015

Task Competency in the Rights Analytic: Mental Health and the Justification for Rights and Duties

The paper concerns the moral status of persons for the purposes of rights-holding and duty-bearing. Developing from Gewirth’s argument to the Principle of Generic Consistency (PGC) and Beyleveld et al.’s Principle of Precautionary Reasoning, I argue in favour of a capacity-based assessment of the task competencies required for choice-rights and certain duties (within the Hohfeldian analytic). Unlike other, traditional, theories of rights, I claim that precautionary reasoning as to agentic status holds the base justification for rights-holding. If this is the basis for generic legal rights, then the contingent argument must be used to explain communities of rights. Much in the same way as two ‘normal’ adult agents may not have equal rights to be an aeroplane pilot, not all adults hold the same task competencies in relation to the exercise of the generic rights to freedom derived from the PGC. In this paper, I set out to consider the rights held by children, persons suffering from mental illness and generic ‘full’ agents. In mapping the developing ‘portfolio’ of rights and duties that a person carries during their life we might better understand the legal relations of those who do not ostensibly fulfil the criteria of ‘full’ agent.

Análise do padrão motor em pessoas com diagnóstico de esquizofrenia: uma abordagem em tempo real

A esquizofrenia é uma perturbação mental grave caracterizada pela coexistência de sintomas positivos, negativos e de desorganização do pensamento e do comportamento. As alterações motoras são consistentemente observadas mas, ainda pouco estudadas na esquizofrenia, sendo relevantes para o seu diagnóstico. Neste quadro, o presente estudo tem como objetivo verificar se os indivíduos com esquizofrenia apresentam alterações na coordenação motora, comparativamente com o grupo sem esquizofrenia, bem como analisar se as disfunções dos sinais neurológicos subtis (SNS) motores se encontram correlacionadas com o funcionamento executivo e com os domínios psicopatológicos da perturbação. No total participaram 29 indivíduos (13 com diagnóstico de esquizofrenia e 16 sem diagnóstico) equivalentes em termos de idade, género, escolaridade e índice de massa corporal. Para avaliar o desempenho motor recorreu-se ao sistema Biostage de parametrização do movimento em tempo real, com a tarefa de lançameto ao alvo; a presença de SNS foi examinada através da Brief Motor Scale; o funcionamento executivo pela aplicação do subteste do Vocabulário e da fluência verbal e a sintomatologia clínica através da Positive and Negative Sindrome Scale. Pela análise cinemática do movimento constatou-se que os indivíduos com esquizofrenia recrutam um padrão motor menos desenvolvido e imaturo de movimento, com menor individualização das componentes (principalmente do tronco e pélvis), necessitando de mais tempo para executar a tarefa, comparativamente com os sujeitos sem a perturbação que evidenciaram um movimento mais avançado de movimento. Os indivíduos com esquizofrenia mostraram índices elevados de disfunção dos SNS (média =6,01) estabelecendo este domínio uma relação boa e negativa com o desempenho verbal (rho Spearman=-0,62) e uma relação forte e positiva com todos os domínios psicopatológicos (rho Spearman=0,74). O estudo da existência de alterações motoras como parte intrínseca da esquizofrenia revela-se pertinente uma vez que possibilita uma compreensão mais aprofundada da sua fisiopatologia e permite que se desenvolvam práticas mais efetivas na área da saúde e reabilitação.

Task assignment algorithms for two-type heterogeneous multiprocessors

Consider the problem of assigning real-time tasks on a heterogeneous multiprocessor platform comprising two different types of processors — such a platform is referred to as two-type platform. We present two linearithmic timecomplexity algorithms, SA and SA-P, each providing the follow- ing guarantee. For a given two-type platform and a given task set, if there exists a feasible task-to-processor-type assignment such that tasks can be scheduled to meet deadlines by allowing them to migrate only between processors of the same type, then (i) using SA, it is guaranteed to find such a feasible task-to- processor-type assignment where the same restriction on task migration applies but given a platform in which processors are 1+α/2 times faster and (ii) SA-P succeeds in finding 2 a feasible task-to-processor assignment where tasks are not allowed to migrate between processors but given a platform in which processors are 1+α/times faster, where 0<α≤1. The parameter α is a property of the task set — it is the maximum utilization of any task which is less than or equal to 1.

Online intra-task device scheduling for hard real-time systems

A large part of power dissipation in a system is generated by I/O devices. Increasingly these devices provide power saving mechanisms, inter alia to enhance battery life. While I/O device scheduling has been studied in the past for realtime systems, the use of energy resources by these scheduling algorithms may be improved. These approaches are crafted considering a very large overhead of device transitions. Technology enhancements have allowed the hardware vendors to reduce the device transition overhead and energy consumption. We propose an intra-task device scheduling algorithm for real time systems that allows to shut-down devices while ensuring system schedulability. Our results show an energy gain of up to 90% when compared to the techniques proposed in the state-of-the-art.

Implementing slot-based task-splitting multiprocessor scheduling

Consider the problem of scheduling a set of sporadic tasks on a multiprocessor system to meet deadlines using a task-splitting scheduling algorithm. Task-splitting (also called semi-partitioning) scheduling algorithms assign most tasks to just one processor but a few tasks are assigned to two or more processors, and they are dispatched in a way that ensures that a task never executes on two or more processors simultaneously. A particular type of task-splitting algorithms, called slot-based task-splitting dispatching, is of particular interest because of its ability to schedule tasks with high processor utilizations. Unfortunately, no slot-based task-splitting algorithm has been implemented in a real operating system so far. In this paper we discuss and propose some modifications to the slot-based task-splitting algorithm driven by implementation concerns, and we report the first implementation of this family of algorithms in a real operating system running Linux kernel version 2.6.34. We have also conducted an extensive range of experiments on a 4-core multicore desktop PC running task-sets with utilizations of up to 88%. The results show that the behavior of our implementation is in line with the theoretical framework behind it.

Practical aspects of slot-based task- splitting dispatching in its schedulability analysis

Consider the problem of scheduling a set of sporadic tasks on a multiprocessor system to meet deadlines using a tasksplitting scheduling algorithm. Task-splitting (also called semipartitioning) scheduling algorithms assign most tasks to just one processor but a few tasks are assigned to two or more processors, and they are dispatched in a way that ensures that a task never executes on two or more processors simultaneously. A certain type of task-splitting algorithms, called slot-based task-splitting, is of particular interest because of its ability to schedule tasks at high processor utilizations. We present a new schedulability analysis for slot-based task-splitting scheduling algorithms that takes the overhead into account and also a new task assignment algorithm.

Static-priority scheduling over wireless networks with multiple broadcast domains

We propose a wireless medium access control (MAC) protocol that provides static-priority scheduling of messages in a guaranteed collision-free manner. Our protocol supports multiple broadcast domains, resolves the wireless hidden terminal problem and allows for parallel transmissions across a mesh network. Arbitration of messages is achieved without the notion of a master coordinating node, global clock synchronization or out-of-band signaling. The protocol relies on bit-dominance similar to what is used in the CAN bus except that in order to operate on a wireless physical layer, nodes are not required to receive incoming bits while transmitting. The use of bit-dominance efficiently allows for a much larger number of priorities than would be possible using existing wireless solutions. A MAC protocol with these properties enables schedulability analysis of sporadic message streams in wireless multihop networks.

Scheduling arbitrary-deadline sporadic task systems on multiprocessors

A new algorithm is proposed for scheduling preemptible arbitrary-deadline sporadic task systems upon multiprocessor platforms, with interprocessor migration permitted. This algorithm is based on a task-splitting approach - while most tasks are entirely assigned to specific processors, a few tasks (fewer than the number of processors) may be split across two processors. This algorithm can be used for two distinct purposes: for actually scheduling specific sporadic task systems, and for feasibility analysis. Simulation- based evaluation indicates that this algorithm offers a significant improvement on the ability to schedule arbitrary- deadline sporadic task systems as compared to the contemporary state-of-art. With regard to feasibility analysis, the new algorithm is proved to offer superior performance guarantees in comparison to prior feasibility tests.

Behavioural development in a matching-to-sample task and token use by an infant chimpanzee reared by his mother

Animal Cognition, V.6, pp. 259–267