666 research outputs found
THE INFLUENCE OF SEX AND ANTHROPOMETRIC PARAMETERS ON THE PARTIAL AND TOTAL VELOCITlES OF PORTUGUESE TOP SWIMMERS
This work studies the variation of some performance indicators - the relative contributions of partial velocities on total speed, the increase of speed induced by the action of lower limbs and the coordination degree of the action of both upper and lower limbs, in order to achieve maximum speed - on Portuguese top swimmers, in the four competitive strokes. The performance indicators were analyzed as functions of the sex of the swimmers and of selected anthropometric parameters (lengths, frontal areas and cross sectional areas of body segments). Twenty eight swimmers, fourteen of each sex, representing one of the best Portuguese competitive teams, were submitted to a standard test situation and to a photographic procedure. Their best times, velocities and somatic characteristics were thereafter determined. 'T' tests and analysis of variance were computed to account for differences in the performance indicators, between male and female swimmers. Anthropometric and performance variables were correlated inside each group. The values of 'T' and 'F' showed significant differences between average scores of male and female groups (
From Words to Music: A Study of Subword Tokenization Techniques in Symbolic Music Generation
Subword tokenization has been widely successful in text-based natural
language processing (NLP) tasks with Transformer-based models. As Transformer
models become increasingly popular in symbolic music-related studies, it is
imperative to investigate the efficacy of subword tokenization in the symbolic
music domain. In this paper, we explore subword tokenization techniques, such
as byte-pair encoding (BPE), in symbolic music generation and its impact on the
overall structure of generated songs. Our experiments are based on three types
of MIDI datasets: single track-melody only, multi-track with a single
instrument, and multi-track and multi-instrument. We apply subword tokenization
on post-musical tokenization schemes and find that it enables the generation of
longer songs at the same time and improves the overall structure of the
generated music in terms of objective metrics like structure indicator (SI),
Pitch Class Entropy, etc. We also compare two subword tokenization methods, BPE
and Unigram, and observe that both methods lead to consistent improvements. Our
study suggests that subword tokenization is a promising technique for symbolic
music generation and may have broader implications for music composition,
particularly in cases involving complex data such as multi-track songs
Error and uncertainty in the accuracy assessment of land cover maps
A thesis submitted in partial fulfillment of the requirements for the degree of Doctor in Information Management, specialization in Geographic Information SystemsTraditionally the accuracy assessment of land cover maps is performed through the comparison of these maps with a reference database, which is intended to represent the ârealâ land cover, being this comparison reported with the thematic accuracy measures through confusion matrixes. Although, these reference databases are also a representation of reality, containing errors due to the human uncertainty in the assignment of the land cover class that best characterizes a certain area, causing bias in the thematic accuracy measures that are reported to the end users of these maps. The main goal of this dissertation is to develop a methodology that allows the integration of human uncertainty present in reference databases in the accuracy assessment of land cover maps, and analyse the impacts that uncertainty may have in the thematic accuracy measures reported to the end users of land cover maps. The utility of the inclusion of human uncertainty in the accuracy assessment of land cover maps is investigated. Specifically we studied the utility of fuzzy sets theory, more precisely of fuzzy arithmetic, for a better understanding of human uncertainty associated to the elaboration of reference databases, and their impacts in the thematic accuracy measures that are derived from confusion matrixes. For this purpose linguistic values transformed in fuzzy intervals that address the uncertainty in the elaboration of reference databases were used to compute fuzzy confusion matrixes. The proposed methodology is illustrated using a case study in which the accuracy assessment of a land cover map for Continental Portugal derived from Medium Resolution Imaging Spectrometer (MERIS) is made. The obtained results demonstrate that the inclusion of human uncertainty in reference databases provides much more information about the quality of land cover maps, when compared with the traditional approach of accuracy assessment of land cover maps
The use of spatially explicit capture-recapture models for estimating Iberian lynx abundance in a newly reintroduced population
From 2015 till 2018, 33 lynxes were released in southeast Portugal (Guadiana valley) as a result of an Iberian reintroduction project. Since then, at least 45 lynxes were born in the wild during 3 breeding seasons. In 2018, a combination of sign search and camera trapping was applied to estimate lynx abundance in the Guadiana reintroduction area, using spatially explicit capture-recapture (SECR) models with the incorporation of sex-specific parameters. A total effort of 7210 trap-days led to 218 independent lynx captures (except for yearlings), which corresponded to 22 adults or sub-adults in 50 stations (28%). The estimated population size was 22â29 individuals (adults and sub-adults) in the 723âŻkm2 study area, leading to a density of 3.4 lynxes (>1-year-old)/100 km2. Individuals were heterogeneously distributed, since most lynxes occurred in clusters with a few lynxes scattered among them. Use of space was sex-dependent and, as expected, males moved more distances than females. Apart from the estimated 22â29 over 1 year-old lynxes, the study detected the presence of 27 yearlings. The reintroduction project is still at an early stage, since the goal for a baseline population has not yet been reached (15 reproductive females) and it is therefore essential to improve organizational issues to implement a viable long-term system covering all critical areas, namely long-term replicable census for population monitoring.publishe
Learning Word Embeddings from the Portuguese Twitter Stream: A Study of some Practical Aspects
This paper describes a preliminary study for producing and distributing a
large-scale database of embeddings from the Portuguese Twitter stream. We start
by experimenting with a relatively small sample and focusing on three
challenges: volume of training data, vocabulary size and intrinsic evaluation
metrics. Using a single GPU, we were able to scale up vocabulary size from 2048
words embedded and 500K training examples to 32768 words over 10M training
examples while keeping a stable validation loss and approximately linear trend
on training time per epoch. We also observed that using less than 50\% of the
available training examples for each vocabulary size might result in
overfitting. Results on intrinsic evaluation show promising performance for a
vocabulary size of 32768 words. Nevertheless, intrinsic evaluation metrics
suffer from over-sensitivity to their corresponding cosine similarity
thresholds, indicating that a wider range of metrics need to be developed to
track progress
A aplicação de modelos especiais de preparação de professores
A procura do sucesso pedagĂłgico tem levado ao desenvolvimento e Ă adopção de metodologias, estratĂ©gias, modelos, experiĂȘncias ou programas de formação de professores que possam contribuir para melhorar as habilidades de ensino e a competĂȘncia para ensinar.
PretendĂamos saber se a aplicação de distintas formas, mĂ©todos ou modelos de preparação de professores para a prĂĄtica docente, tinha tradução, mais tarde, durante a prĂĄtica pedagĂłgica ou estĂĄgio, em diferenças significativas na sua acção.
Para o tentar saber, decidimos preparar os participantes através de quatro processos, perfeitamente tipificados, relacionados com o que é pråtica comum em algumas das instituiçÔes de formação, como o ensino com pares, o microensino com colegas, o microensino com alunos reais, e uma preparação clåssica sem a utilização de qualquer um destes modelos, e mais tarde, durante a sua pråtica pedagógica, efectuar a anålise do processo de ensino que nos permitisse encontrar as respostas pretendidas.
A observação das cento e quarenta e quatro aulas que os quarenta e oito professores de Educação FĂsica, em situação de prĂĄtica pedagĂłgica do estĂĄgio para professores do segundo ciclo do ensino BĂĄsico, leccionaram a mil cento e dezassete alunos, permitiram-nos ficar com uma imagem, sob diferentes perspectivas, desses aspectos do comportamento de professores e alunos.
A interrogação dos professores e dos alunos possibilitaram um conhecimento de alguns dos aspectos que nĂŁo se vĂȘm mas que interferem e condicionam o processo de ensino aprendizagem.
O estudo colocou em evidĂȘncia as diferenças na acção dos professores preparados pelos distintos procedimentos, permitindo-nos concluir que a formação de professores de Educação FĂsica atravĂ©s dos modelos de preparação para a prĂĄtica docente utilizados, em termos globais, nĂŁo se traduz numa conduta comportamental diferente, mas em termos particulares, ficou evidente que essas diferenças eram significativas para alguns aspectos em anĂĄlise
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