ℒ2-Gain of double integrators with saturation nonlinearity

This note uses quadratic surface Lyapunov functions (SuLFs) to efficiently check if a double integrator in feedback with a saturation nonlinearity has ℒ2-gain less than γ > 0. We show that for many such systems, the ℒ2-gain is nonconservative in the sense that this is approximately equal to the lower bound obtained by replacing the saturation with a constant gain of 1. These results allow the use of classical analysis tools like µ-analysis or integral quadratic constraints to analyze systems with double integrators and saturations, including servo systems like some mechanical systems, satellites, hard disks, compact disk players, etc

Robust Network Reconstruction in Polynomial Time

This paper presents an efficient algorithm for robust network reconstruction of Linear Time-Invariant (LTI) systems in the presence of noise, estimation errors and unmodelled nonlinearities. The method here builds on previous work on robust reconstruction to provide a practical implementation with polynomial computational complexity. Following the same experimental protocol, the algorithm obtains a set of structurally-related candidate solutions spanning every level of sparsity. We prove the existence of a magnitude bound on the noise, which if satisfied, guarantees that one of these structures is the correct solution. A problem-specific model-selection procedure then selects a single solution from this set and provides a measure of confidence in that solution. Extensive simulations quantify the expected performance for different levels of noise and show that significantly more noise can be tolerated in comparison to the original method.Comment: 8 pages, to appear in 51st IEEE Conference on Decision and Contro

Global analysis of piecewise linear systems using impact maps and surface Lyapunov functions

This paper presents an entirely new constructive global analysis methodology for a class of hybrid systems known as piecewise linear systems (PLS). This methodology infers global properties of PLS solely by studying the behavior at switching surfaces associated with PLS. The main idea is to analyze impact maps, i.e., maps from one switching surface to the next switching surface. Such maps are known to be "unfriendly" maps in the sense that they are highly nonlinear, multivalued, and not continuous. We found, however, that an impact map induced by an linear time-invariant flow between two switching surfaces can be represented as a linear transformation analytically parametrized by a scalar function of the state. This representation of impact maps allows the search for surface Lyapunov functions (SuLF) to be done by simply solving a semidefinite program, allowing global asymptotic stability, robustness, and performance of limit cycles and equilibrium points of PLS to be efficiently checked. This new analysis methodology has been applied to relay feedback, on/off and saturation systems, where it has shown to be very successful in globally analyzing a large number of examples. In fact, it is still an open problem whether there exists an example with a globally stable limit cycle or equilibrium point that cannot be successfully analyzed with this new methodology. Examples analyzed include systems of relative degree larger than one and of high dimension, for which no other analysis methodology could be applied. This success in globally analyzing certain classes of PLS has shown the power of this new methodology, and suggests its potential toward the analysis of larger and more complex PLS

Teoria Psicanalítica da Fantasia e Análise Fílmica

SFRH/BPD/84773/2012 PTDC/FIL-FIL/098143/2008Neste artigo parto da hipótese que o cinema causa um prazer estético aos sujeitos humanos porque lhes permite objectivar processos mentais, sobretudo desejos inconscientes. O dispositivo teórico que procurarei explicitar é o da teoria psicanalítica da fantasia tal como foi elaborada pela corrente psicanalítica que partiu de Freud, Melanie Klein, Lacan, Laplanche tendo sido usada na análise fílmica e por autores como Elizabeth Cowie e Christian Metz. A minha principal referência será, no entanto, o último período do ensino lacaniano tal como tem sido desenvolvido pelo representante mais conhecido da Escola Lacaniana Eslovena, Slavoj Zizek. Apresentarei no final alguns exemplos do método dele.proofpublishe

Not harmful delusions – an interpretation

UID/FIL/00183/2013The aim of this article is to identify a characteristic of delusions: that which makes them pathological. It may appear a bit strange at first because one believes that delusions are just a pathological alteration of the mind. However, some authors have shown that although pathological delusions are the most studied, not all delusions have necessarily harmful consequences for the delirious subject or for others. Hence, it seems pertinent to question what makes delusions a pathological state. Although delusions are associated with several syndromes here I take mainly as a reference delusions that are related to the “Schizophrenia Spectrum and Other Psychotic Disorders” in the DSM 5 where they are described as “false beliefs”. Some authors think that delusions are in fact false beliefs and others that delusions are not beliefs but experiences. I also think that delusions are experiences and argue in favour of the Gallagher’s Multiple Realities (MR) model of delusions which is based on the phenomenology of Schütz. According to Schütz, everyday reality is not the only reality in which consciousness can be found. Developing an idea of William James, which states that in the Universe there are several "sub-universes", Schütz maintains that there are several realities which he calls "finite provinces of sense", each having a different cognitive style, to which a specific tension of consciousness belongs, a specific epoché, a prevailing form of spontaneity, a specific form of self-experience, a specific form of socialization, and a specific perspective of time. Gallagher develops the idea of Schütz and includes delusions as a reality along with other alternative realties as dream, fiction or science. However, I think the MR model is not incompatible with the “belief model” because beliefs could exist within the experience of delusional reality. After the exposition of the MR model I would try to explain why within this model one can understand that not all delusions are harmful for the subject or the others. The subject can enter into a different reality – such assomeone who is reading a novel and leaves the reality of the world around them – but this does not always have harmful consequences. Not because the subject ceases to carry the delusion into everyday reality, but because the content of this delusion could have positive consequences or at least not harmful consequences. In this way, one can explain, for example, some “mystical” delusions or some artistic creative delusions which seems not to have negative consequences even if there is confusion between everyday reality and delusion reality (according to MR model).publishersversionpublishe

O combate à radicalização no extremismo islâmico : a contrarradicalização e a des-radicalização

Em termos académicos tem sido despendido bastante esforço para compreender o processo de radicalização islâmica, embora escasseiem os estudos sobre o processo de desradicalização, no qual um extremista renuncia à violência, deixa um grupo ou um movimento - ou rejeita uma visão radical do mundo. Importa assim perceber o combate à radicalização islâmica, comparando os programas implementados em países do Médio Oriente e Ásia com os da Europa, analisando as diferentes estratégias e alguns desafios para no final se extraírem algumas conclusões

CRITICAL ASSESSMENT OF THE QUALITY OF THE ENGLISH LANGUAGE TEACHER TRAINING PROGRAMME FOR PRIMARY SCHOOLS IN ZAMBÉZIA PROVINCE, MOZAMBIQUE

This paper presents a contextual approach on the analysis of the quality of English language teachers training model 10 + 1 at the teacher training college in Zambezia province. The paper focuses on the quality in a didactic-pedagogical perspective and the teacher training process at the teacher training college for primary schools. The approach is targeted at the analysis of the quality in teacher education. For the effectiveness of this paper, it was identified and described the main factors that influence the quality, and the paper suggests strategies for the improvement of the English language teacher training at the teacher training colleges in Quelimane, Nicoadala and Morrumbala. To match the theme and the analysis expectations, the qualitative methodology was chosen for this study by using interviews, documental analysis and review of the literature as a means of data collection. The interviewer draws analysis of the information taking into account the responses from the respondents and the real situation observed in the field where the research took place. Henceforth, through the analysis from the interviewees and information from the documents it is concluded that the quality of English language teacher training course at the Teacher Training Colleges is unsatisfactory due to several problems of the reality of the English language teacher training process itself. Este artigo apresenta uma abordagem contextual sobre a análise da qualidade de formação de professores de inglês do modelo 10 + 1, na província da Zambézia. O artigo enfoca a qualidade de formação de professores de inglês numa perspectiva didáctico-pedagógica Para a eficácia deste artigo, foram identificados e descritos os principais factores que influenciam a qualidade, e o artigo sugere estratégias para a melhoria da formação de professores de inglês nos institutos de formação de professores em Quelimane, Nicoadala e Morrumbala. Para corresponder ao tema e às expectativas de análise, a metodologia qualitativa foi escolhida para este estudo por meio de entrevistas, análise documental e revisão da literatura como meio de produção de dados. O pesquisador faz uma análise da informação tomando em conta as respostas dos entrevistados e a situação real observada no campo em que a pesquisa ocorreu. Através da análise dos entrevistados e informações dos documentos conclui-se que a qualidade do curso de formação de professores de inglês nos institutos de formação de professores é insatisfatória devido a vários problemas da própria realidade do processo de formação.  Article visualizations

CRITICAL ANALYSIS IN USE OF COMMUNICATIVE COMPETENCE TO IMPROVE TEACHER TRAINEES’ ORAL ABILITY AND TEACHING OF ENGLISH AT THE TEACHER TRAINING COLLEGES IN ZAMBÉZIA, MOZAMBIQUE

English language teachers’ trainees at Zambézia Colleges have difficulties in English language speech, which is shown through lack of confidence and fluency when teaching in classes during the teaching practices. It is the topic built on the basis of the frequent interactions with the teacher trainees and observations made through English language teaching practices. Critical analysis in Use of Communicative Competence to Improve Oral Ability and Teaching of English Language Learners at the Teachers' Training Institutes of Zambézia. Dell Hymes (1972) is the proponent of the communicative competence approach under the Sociolinguistics perspective, which later was framed under English language teaching by Canale and Swain (1980) and Canale (1983). It is a fact that the English teacher trainees and teacher trainers need to be helped with current Communicative Language Teaching and Learning Approaches to enhance the quality of their speech as teachers as well as language communicators. The qualitative approach was chosen for this study based on discussions and review of several authors who have written about communicative competence, communicative language teaching and current training procedures to bring out solid suggestions for further improvements on the English language teacher training process so that the trainees must have oral fluency in English language. The current study found out that clear and several teaching activities that can help the teacher trainees to perform fluently and competently during and when and start teaching in the schools. Os estudantes do curso de Inglês nos institutos de formação de professores na Zambézia têm dificuldades no discurso da língua inglesa, o que é demonstrado pela falta de segurança e fluência durante as práticas pedagógicas. Este é um artigo construído com base nas interacções frequentes com os formandos e observações feitas através de práticas de ensino de língua inglesa e do trabalho de pesquisa de doutoramento. Assim, o artigo faz uma análise crítica no uso da competência comunicativa para melhoria das capacidades orais dos formandos e o ensino da língua inglesa nos institutos de formação de professores na província da Zambézia. Dell Hymes (1972) é o proponente da abordagem da competência comunicativa, sob a perspectiva Sociolinguística, que mais tarde foi enquadrada no ensino da língua inglesa por Canale e Swain (1980) e Canale (1983). É um facto que os formandos de professores de inglês e formadores de professores precisam de apoio didáctico-pedagógico com as actuais abordagens de ensino e aprendizagem de ensino de inglês para a melhoria da qualidade do discurso como professores e também como comunicadores de línguas. A abordagem qualitativa foi escolhida para este estudo com base nas discussões e revisão de vários autores que escreveram sobre competência comunicativa, ensino da linguagem comunicativa e procedimentos de formação mais adequados para melhorias no processo de formação de professores de língua inglesa. O presente estudo constata que há actividades de ensino bem claras e diversas que podem ajudar os professores de inglês em formação a aquisição de desempenho fluente e com competência durante a formação e no processo de leccionação nas escolas primárias.  Article visualizations