Identificações em alinhamentos policiais: factores determinantes

Mestrado em Psicologia ForensePor vezes a prova testemunhal é o único meio que temos para resolver um crime. Contudo vários estudos demonstram a ausência de validade desta prova uma vez que a percentagem de erros na identificação de suspeitos pode ascender aos 75%. Os estudos existentes que incluem alinhamentos e os factores determinantes na percentagem de acertos (tipo de alinhamento e presença de alvo) não são conclusivos. Perante isso a presente investigação visa estudar, na população portuguesa, esses factores que a literatura considera preponderantes, bem como incluir uma variável ainda não estudada e que julgamos poder interferir no número de acertos: o tipo de crime (contra bens ou contra pessoas). Este estudo visa também controlar diversas variáveis que a literatura aponta como parasitas. A amostra é constituída por 64 participantes (34 homens e 30 mulheres) com idades compreendidas entre os 18 e 65 anos. Os participantes são provenientes de estratos sociais e de níveis de escolaridade diversificados, com o objectivo de conceder uma maior validade ecológica ao estudo. O presente estudo foi concebido com um desenho experimental 2x2x2 onde os factores são o tipo de alinhamento (simultâneo ou sequencial), a presença do alvo no alinhamento (presente ou ausente), e o tipo de crime (crime contra bens ou crime contra pessoas). O tipo de alinhamento e a presença do alvo são variáveis inter-sujeitos, sendo o tipo de crime uma variável intra-sujeitos. Os resultados obtidos sugerem que os diversos procedimentos parecem conduzir a diferenças pouco significativas entre si. Ainda assim parecem haver algumas diferenças, ainda que ao nível absoluto, entre os dois tipos de crime. Especificamente, quando confrontados com o crime contra pessoas, os indivíduos dão mais erros do que quando expostos ao crime contra bens. Também os efeitos das variáveis tipo de alinhamento e presença do alvo diferem de algum modo entre os dois tipos de crime. Assim sugere-se que esta variável deva ser tida em conta em estudos futuros desta natureza. Mediante análise global, cerca de 70 % dos indivíduos identificaram um inocente, cedendo ao direito informação sobre o real valor da prova por reconhecimento num país onde esta é meio de prova.Sometimes eyewitness testimony is the only way we have to solve a crime. However several studies have demonstrated the reduced validity of this evidence, since the percentage of errors in suspect identification could be up 75%. Previous studies that included line-ups and investigated the factors that critically influence the percentage of correct responses (type of line-up and presence of the target) are not conclusive. Thus, the present study aims to investigate, in the Portuguese population, the main factors suggested in the literature which affect accuracy in suspect identification in criminal line-ups. Additionally, we have included a variable that has not been studied yet and that we believe can affect the number of hits: the type of crime (against property or against persons). Finally, this study also aims to control a number of issues that the literature points out as confounding variables. The sample consisted of 64 participants (34 men and 30 women) between 18 and 65-years-old. Participants belong to diverse social and educational levels, with the aim of providing greater ecological validity to the study. The experimental design is a 2x2x2, with type of line-up (simultaneous or sequential) and presence of the target (present or absent) as between-subjects factors, and type of crime (against property or against persons) as within-subjects factor. Results suggested that the different procedures seem to lead to minor differences between them. Yet, in absolute numbers, some differences were observed between the two types of crime. Namely, when individuals were confronted with the crime against people, they made more identification errors than when they observed the crime against property. Moreover, the effects of the variables type of line-up and presence of the target differed somewhat between the two types of crime. Thus it is suggested that this variable should be taken into account in future studies of this type. In global terms, we verified that about 70% of the times participants identified an innocent person. This finding provides significant information to courts of law about the real value of eyewitness identifications in a country where this is considered valid evidence

Query driven sequence pattern mining

The discovery of frequent patterns present in biological sequences has a large number of applications, ranging from classification, clustering and understanding sequence structure and function. This paper presents an algorithm that discovers frequent sequence patterns (motifs) present in a query sequence in respect to a database of sequences. The query is used to guide the mining process and thus only the patterns present in the query are reported. Two main types of patterns can be identified: flexible and rigid gap patterns. The user can choose to report all or only maximal patterns. Constraints and Substitution Sets are pushed directly into the mining process. Experimental evaluation shows the efficiency of the algorithm, the usefulness and the relevance of the extracted patterns.Fundação para a Ciência e a Tecnologia (FCT

Protein sequence pattern mining with constraints

Considering the characteristics of biological sequence databases, which typically have a small alphabet, a very long length and a relative small size (several hundreds of sequences), we propose a new sequence mining algorithm (gIL). gIL was developed for linear sequence pattern mining and results from the combination of some of the most efficient techniques used in sequence and itemset mining. The algorithm exhibits a high adaptability, yielding a smooth and direct introduction of various types of features into the mining process, namely the extraction of rigid and arbitrary gap patterns. Both breadth or a depth first traversal are possible. The experimental evaluation, in synthetic and real life protein databases, has shown that our algorithm has superior performance to state-of-the art algorithms. The use of constraints has also proved to be a very useful tool to specify user interesting patternsFundação para a Ciência e a Tecnologia (FCT

Psicofisiologia do testemunho ocular

Doutoramento em PsicologiaAs testemunhas oculares são muitas vezes o único meio que temos para aceder à autoria de um crime. Contudo, apesar dos 100 anos de evidência de erros no testemunho ocular, a consciência das suas limitações como meio de prova só ganhou força no advento do ADN. De facto os estudos de exoneração mostraram que 70 % das ilibações estavam associadas a erros de testemunho ocular. Estes erros têm um impacto social elevado principalmente os falsos positivos, por colocar inocentes na prisão. De acordo com a literatura, deverão ser utilizadas novas abordagens para tentar reduzir o numero de erros de identificação. Destas abordagens, destacam-se a análise dos padrões de movimentos oculares e os potenciais evocados. Nos nossos estudos utilizamos essas novas abordagens com o objetivo de examinar os padrões de acerto ou de identificação do criminoso, usando um paradigma de deteção de sinal. No que diz respeito aos movimentos oculares, não foram encontrados padrões robustos de acerto. No entanto, obtiveram-se evidências oculométricas de que a fusão de dois procedimentos (Alinhamento Simultâneo depois de um Alinhamento Sequencial com Regra de Paragem) aumenta a probabilidade de acerto. Em relação aos potenciais evocados, a P100 registou maior amplitude quando identificamos um inocente. Este efeito é concomitante com uma hiperactivação no córtex prefrontal ventromedial (CPFVM) identificada na análise de estimação de fontes. Esta hiperativação poderá estar relacionada com uma exacerbação emocional da informação proveniente da amígdala. A literatura relaciona a hiperativação no CPFVM com as falsas memorias, e estes resultados sugerem que a P100 poderá ser um promissor indicador de falsos positivos. Os resultados da N170 não nos permitem associar este componente ao acerto na identificação. Relativamente à P300, os resultados mostram uma maior amplitude deste componente quando identificamos corretamente um alvo, mas não diferiu significativamente de quando identificamos um inocente. Porém, a estimação de fontes mostrou que nessa janela temporal (300-600 ms) se verifica uma hipoativação dos Campos Oculares Frontais (COF) quando um distrator é identificado. Baixas ativações dos COF estão relacionadas com redução da eficiência de processamento e com a incapacidade para detetar alvos. Nas medidas periféricas, a eletromiografia facial mostrou que a maior ativação do corrugador e a menor ativação do zigomático são um bom indicador de quando estamos perante um criminoso. No que diz respeito ao ritmo cardíaco, a desaceleração esperada para os alvos devido à sua saliência emocional apenas foi obtida quando a visualização de um alvo foi acompanhada por um erro na identificação (i.e., um falso negativo). Neste trabalho de investigação parece que o sistema nervoso periférico está a responder corretamente, identificando o alvo, por ser emocionalmente mais saliente, enquanto que a modulação executiva efectuada pelo CPFVM conduz ao falso positivo. Os resultados obtidos são promissores e relevantes, principalmente quando o resultado de um erro poderá ser uma condenação indevida e, consequentemente, uma vida injustamente destruída.Eyewitnesses are often the only way we can access the author of a crime. However, despite 100 years of evidence of errors in eyewitness testimony, awareness of its limitations only gained strength with the advent of DNA. In fact, 70% of exonerations have been associated with eyewitness errors. These errors have a high social impact, mainly false positives. According to the literature, new approaches to try to reduce the number of identification errors should be used. Of these, the study of oculometric patterns and event-related Potentials (ERP) stand out. In our studies, these new approaches were used with the objective of examining patterns of accuracy, using a signal detection paradigm. Regarding eye movements, no entirely clear patterns were found. However, there was oculometric evidence that the merging of two procedures (Simultaneous Lineup after a Sequential Lineup with Stopping Rule) increases performance accuracy. Regarding ERPs, the P100 registered a larger amplitude when an innocent was identified. This effect is concomitant with a hyperactivation in the ventromedial prefrontal cortex (VMPFC) identified by source estimation analysis. This hyperactivation might be related to an emotional exacerbation of the information coming from the amygdala. The literature relates the hyperactivation in the VMPFC with false memories, and these results suggest that the P100 component might be a promising marker of false positive errors. The results of the N170 do not allow to associate this component with accuracy. Regarding the P300, the results showed a greater amplitude of this component when a target was correctly identified but did not differ significantly from when an innocent was identified. However, source analysis in this time window (300-600 ms) showed a hypoactivation of Frontal Eye Fields (FEF) when a distractor was identified. FEF inactivations are related to the reduction of processing efficiency and to the inability to detect a target. Concerning the peripheral measures, facial electromyography showed that the greater activation of the corrugator and the lower activation of the zygomaticus are a good marker of when we are facing a perpetrator. Regarding heart rate, the expected deceleration for the targets due to their emotional salience was only obtained when the visualization of a target was accompanied by an error in the identification (i.e., a miss). In this research it seems that the peripheral nervous system is responding correctly, identifying the target, because it is emotionally more salient, while the executive modulation carried out by the VMPFC causes the false positive error. The results presently obtained are promising and relevant, especially when the result of an error might be an undue condemnation of an innocent and consequently a destroyed life

Sobre o Método de Mahler para transcendência

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, 2021.Seja $\mathfrak{a}=(a_n)_{n\geq 0}$ uma sequência de inteiros positivos. Neste trabalho, estudamos o comportamento aritmético de valores da função $f_\mathfrak{a}(z)=\sum_{n\geq 0}z^{a_n}$. Primeiro, no caso de uma sequência superexponencial $\mathfrak{a}$, mostramos (em particular) que $f_\mathfrak{a}(\alpha)$ é um número transcendente, para todo número algébrico não nulo $\alpha\in B(0,1)$. Depois disso, o objetivo principal é estudar o caso em que $\mathfrak{a}$ é uma sequência exponencial. Para isso, apresentamos e usamos o chamado Método de Mahler (que é particularmente útil para funções que satisfazem alguma equação funcional) para obter resultados de transcendência sobre valores de funções em argumentos algébricos.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) e Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).Let $\mathfrak{a}=(a_n)_{n\geq 0}$ be a sequence of positive integers. In this work, we study the arithmetic behavior of values of the function $f_\mathfrak{a}(z)=\sum_{n\geq 0}z^{a_n}$. First, in the case of a super-exponential sequence $\mathfrak{a}$, we show (in particular) that $f_\mathfrak{a}(\alpha)$ is a transcendental number, for all nonzero algebraic number $\alpha\in B(0,1)$. After that, the main focus is to study the case in which $\mathfrak{a}$ is an exponencial sequence. For that, we present and use the called Mahler's method (which is particularly useful for functions satisfying some functional equation) to derive transcendental results about values of functions at algebraic arguments

Assistive Robotic Hand Orthosis (ARHO) controlled with EMG: evaluation of a preliminary prototype*

Hand impairment severely limits basic activities of daily living (ADL). The use of motorized hand orthoses may provide enough functional assistance to perform basic tasks, such as grasping objects. Several prototypes have been proposed in the last decade, but there are still no solutions with the desired features regarding the weight, wearability and functionality. This paper describes the overall implementation of a prototype of an assistive robotic hand orthosis (ARHO) for object grasping, that can be triggered manually or by the detection of muscular activity in the forearm using surface electromyography (sEMG). The system is being specifically designed for a case study of a person with hemiplegia resulting from a peri-insular hemispherectomy. The proposed orthosis is a very preliminary but functional prototype, still far from the desired features mentioned above, but serves to show all the modules composing a low-cost implementation, and above all, to understand all the constraints and difficulties in designing such a system.info:eu-repo/semantics/publishedVersio

Spatial clustering of molecular dynamics trajectories in protein unfolding simulations

Molecular dynamics simulations is a valuable tool to study protein unfolding in silico. Analyzing the relative spatial position of the residues during the simulation may indicate which residues are essential in determining the protein structure. We present a method, inspired by a popular data mining technique called Frequent Itemset Mining, that clusters sets of amino acid residues with a synchronized trajectory during the unfolding process. The proposed approach has several advantages over traditional hierarchical clustering.The authors acknowledge the support of the "Fundacao para a Ciencia e Tecnologia,Portugal, and the program FEDER, through grant PTDC/BIA-PRO/72838/2006 (to PJA and RMMB) and the Fellowships SFRH/BPD/42003/2007(to PGF) and SFRH/BD/16888/2004 (to CGS). We thank the Center for Computational Physics, Departamento de Fisica, Universidade de Coimbra, for the computer resources provided for the MD simulations

Mining approximate motifs in time series

The problem of discovering previously unknown frequent patterns in time series, also called motifs, has been recently introduced. A motif is a subseries pattern that appears a significant number of times. Results demonstrate that motifs may provide valuable insights about the data and have a wide range of applications in data mining tasks. The main motivation for this study was the need to mine time series data from protein folding/unfolding simulations. We propose an algorithm that extracts approximate motifs, i.e. motifs that capture portions of time series with a similar and eventually symmetric behaviour. Preliminary results on the analysis of protein unfolding data support this proposal as a valuable tool. Additional experiments demonstrate that the application of utility of our algorithm is not limited to this particular problem. Rather it can be an interesting tool to be applied in many real world problems.Fundação para a Ciência e a Tecnologia (FCT).Fundo Europeu de Desenvolvimento Regional (FEDER) - POCTI/BME/49583/2002; SFRH/BD/13462/2003; SFRH/BD/16888/2004

Topic maps applied to PubMed

This paper presents a topic map approach to PubMed in order to create a knowledge representation for this information system. PubMed is a free search engine that gives very full coverage of the related biomedical sciences. With more than 17 millions of citations since 1865, PubMed users have several problems to find the papers desired. So, it is necessary to organize these concepts in a semantic network. To achieve this objective, we use the Metamorphosis system, choosing the keywords from MeSH ontology. This way, we obtain an ontological index for PubMed, making easier to find specific papers.(undefined