Relative Age Effect of Olympic Athletes in Beijing 2008

Research on expert performance field revealed a strong trend in the association of the birth dates of elite athletes to the first trimesters of the year (Wattie et al. 2008). The aim of this study was to analyze the birth date distribution of all top elite athletes who participated in Olympic Games at Beijing 2008. Athletes (n = 18.132) were divided according to gender, continent and sports. The birth dates of the athletes were divided into quarters. To analyze the distribution of the population by quarter we used the Chi-square test. Results showed statistical differences in the distribution for the total population, and for females and males population, showing a trend for athletes to born in the earlier part of the year. Relatively to the continent, statistical differences appear only in Africa, Asia and Europe. In terms of sports, statistical differences were found in the distribution of 6 sports in females (athletics, badminton, basketball, modern pentathlon, rowing, and swimming) and 9 sports in males (athletics, basketball, canoeing, road cycling, football, handball, rowing, swimming, and volleyball). In all cases, distribution showed a higher participation of athletes born in the beginning of the year. These results show a clear influence of the athlete’s date of birth in the achievement of expert performance, in several sports and continents

Heart rate response to duration and players’ number variations in Futsal specific drill

Introduction: Recent findings demonstrate that Futsal is a multiple-sprint sport in which high-intensity exercise constitutes a greater proportion of match time than all other team sports (Barbero-Alvarez et al., 2008), but the research of training intensity is a unknown way. Sport specific drills with variations are constantly used in Futsal practices, however the knowledge about how these variations influence drill intensity is very insufficient (Duarte et al., 2007). Therefore, this study aimed to measure the effects of duration and players’ number variations in a Futsal specific drill by the elicited percentage of maximal Heart Rate (HRmax%) and percentage of time spent in three Heart Rate intensity zones (HRzone185%HRmax). Methods: The studied sample was constituted by eight players from a Portuguese First Division team [age 25.9(4.5); weight 67.6(7.5); height 1.7(0.1); BMI 22.4(2.0)]. The exercise testing consists in a “half-pitch game” with official rules. To test the effect of players’ numerical relations, the drill was played in 4v4, 3v3 and 2v2 conditions, during 4 minutes and followed with an active break (continuous running with low intensity) of 4 minutes. In order to test the effect of exercise duration, the drill was played during 4 minutes and 10 minutes conditions, maintaining an active break of 4 minutes. Results: In players’ number variation statistically significant differences were found in HRmax% [4v4 81.5(10.6) to 3v3 86.8(7.3) and to 2v2 87.9(11.7); p=0.01] and in percentage of time spent in HRzone2 [35.4% in 4v4, 12.5% in 3v3 and 10.4% in 2v2; p=0.01]. In the exercise duration statistically significant differences were found only in percentage of time spent in HRzone3 [50% in 4 minutes and 29.2% in 10 minutes; p=0.04]. Conclusions: The decrease in the number of players resulted in an intensity increase, probably due to the larger ratio of area per player and to the progressive decision making constraint by the limited choices of the ball carrier to cooperating with the teams-mate. The variation of the exercise duration did not induce any change in HRmax%. However, playing the “half-pitch game” during 4 minutes period brings more significant percentage of time spent in higher Heart Rate zone and induce more elevated physiological stimulation. Keywords: Heart Rate, Specific Drill, Futsa

Heart rate response to duration and players’ number variations in Futsal specific drill

Recent findings demonstrate that Futsal is a multiple-sprint sport in which high-intensity exercise constitutes a greater proportion of match time than all other team sports (Barbero-Alvarez et al., 2008), but the research of training intensity is a unknown way. Sport specific drills with variations are constantly used in Futsal practices, however the knowledge about how these variations influence drill intensity is very insufficient (Duarte et al., 2007). Therefore, this study aimed to measure the effects of duration and players’ number variations in a Futsal specific drill by the elicited percentage of maximal Heart Rate (HRmax%) and percentage of time spent in three Heart Rate intensity zones (HRzone185%HRmax). The studied sample was constituted by eight players from a Portuguese First Division team [age 25.9(4.5); weight 67.6(7.5); height 1.7(0.1); BMI 22.4(2.0)]. The exercise testing consists in a “half-pitch game” with official rules. To test the effect of players’ numerical relations, the drill was played in 4v4, 3v3 and 2v2 conditions, during 4 minutes and followed with an active break (continuous running with low intensity) of 4 minutes. In order to test the effect of exercise duration, the drill was played during 4 minutes and 10 minutes conditions, maintaining an active break of 4 minutes. In players’ number variation statistically significant differences were found in HRmax% [4v4 81.5(10.6) to 3v3 86.8(7.3) and to 2v2 87.9(11.7); p=0.01] and in percentage of time spent in HRzone2 [35.4% in 4v4, 12.5% in 3v3 and 10.4% in 2v2; p=0.01]. In the exercise duration statistically significant differences were found only in percentage of time spent in HRzone3 [50% in 4 minutes and 29.2% in 10 minutes; p=0.04]. The decrease in the number of players resulted in an intensity increase, probably due to the larger ratio of area per player and to the progressive decision making constraint by the limited choices of the ball carrier to cooperating with the teams-mate. The variation of the exercise duration did not induce any change in HRmax%. However, playing the “half-pitch game” during 4 minutes period brings more significant percentage of time spent in higher Heart Rate zone and induce more elevated physiological stimulation

Effects of Exercise Duration and Number of Players in Heart Rate Responses and Technical Skills During Futsal Small-sided Games

In the design of training programs, it is common for coaches to modify task constraints to conduct the drill intensity at the targeted level. Sport specific drills with variations are constantly used in Futsal practices, however the knowledge about how these variations influence drill intensity and technical demands is very scarce. The purpose of this study was to measure the physiological and technical effects of both duration and variations in the numbers of players in futsal specific drills. Heart rates and technical skills of 8 semi-professional futsal players were recorded during four specific drills. The experimental protocol consisted in a half-court game with official rules, played in 4v4, 3v3 and 2v2, each during 4 minutes and 4v4 during 10 minutes. It was maintained an active break of 4 minutes between each repetition. The lowest %HRmax was observed in response to the 4v4 drill independent of the exercise duration. In players’ number variation statistically significant differences were found in the percentage of time spent between 65-85%HRmax, in the number of successive contacts with the ball and number of dribbles. In exercise duration, statistically significant differences were found in percentage of time spent above 85%HRmax, in the number of successive contacts with the ball, number of dribbles and number of tackles. The decrease in the number of players and exercise duration resulted in intensity increases and more frequent individual tactical actions

Falemos de casas. A habitação em torno de um vazio nuclear. Princípios de reabilitação do alto da Cova da Moura.

Mestrado em ArquitecturaO presente exercício constitui-se como hipótese no âmbito de um trabalho final de mestrado, conducente ao grau de Mestre. Um trabalho de projecto, original e especialmente realizado para este fim, do qual é parte integrante um relatório de investigação, como base teórica que orienta e informa todo o processo de formalização do objecto, e que tenta demonstrar que teoria e prática devem caminhar juntas na concepção de um projecto de arquitectura. O principal objectivo é o de propor, no contexto particular do Bairro do Alto da Cova da Moura, estratégias integradas de desenvolvimento, assentes na implementação de unidades habitacionais autónomas e sustentáveis que, impondo novas lógicas de execução, promovam soluções de espaço arquitectónico e urbano qualificados, integrando uma visão crítica sobre os problemas das sociedades contemporâneas no contexto de uma forte densificação e saturação populacional. Estas estratégias tentem a sua fundamentação num suporte teórico de investigação, que orienta e informa todo o processo de formalização do objecto. Investigar o interior da habitação em torno de um vazio nuclear tem como objectivo fundamental perceber a importância do pátio comum nalgumas concepções de alojamento colectivo, comunitário e cooperativo, particularmente em propostas de alojamento operário na cidade industrial. Entender este vazio comum como espaço nuclear, organizador e aglutinador, que expressa espacialmente o sentido comunitário de um conjunto edificado. Reconhecer e reposicionar esta tipologia habitacional, entretanto distante, no processo de produção de habitação urbana, particularmente em conjuntos urbanos densamente povoados. É neste contexto, e com carácter didáctico, que deverá ser entendido o presente trabalho, num quadro experimental de curta duração, inserido num mundo académico que procura dar o seu contributo para a resolução de situações complexas e reais.This work has been established as a hypothesis in a Masters final paper leading to the degree of MSc. This is a project work, original and specially made for this purpose, for which it was included an investigation report, as a theoretical framework that guides and informs the whole formalization process of the object, as also as tries to demonstrate that theory and practical approaches should be together in a architecture conception process. The main objective of this paper is to propose integrated development strategies, in the particular context of Bairro Alto da Cova da Moura, based on the implementation of autonomous and sustainable housing units that, through the imposition of a new logic of implementation, promotes solutions of qualified architectural and urban spaces questions, and also including a critical view over the problems of contemporary societies, in a context of a strong densification and saturation process. These strategies are relied on theoretical research that guides and informs about the whole formalization process of the object. The investigation of the inside of a building complex around a nuclear emptiness aims to understand the importance of the common courtyard in some collective, community and cooperative accommodation concepts, which is vital to proposals for proletarian housing in industrial towns. Understand this common emptiness as nuclear space, organizing and assembling, which expresses the spatial sense of community of an building complex. Recognize and reposition this housing typology, however distant, in the production process of urban housing, particularly in densely populated urban centers. It is in this context, and with an educational aspect, that this work should be understood, inserted in a short term experimental and academic scenario, managing to contribute to the resolution of complex and real situations

SSTS: A syntactic tool for pattern search on time series

We would like to acknowledge the financial support obtained from North Portugal Regional Operational Programme (NORTE 2020), Portugal 2020 and the European Regional Development Fund (ERDF) from European Union through the project Symbiotic technology for societal efficiency gains: Deus ex Machina (DEM), NORTE-01-0145-FEDER-000026. We would like to acknowledge as well the projects AHA CMUP-ERI/HCI/0046 and INSIDE CMUP-ERI/HCI/051/2013 both financed by Fundcao para a Ciencia e Tecnologia (FCT).Nowadays, data scientists are capable of manipulating and extracting complex information from time series data, given the current diversity of tools at their disposal. However, the plethora of tools that target data exploration and pattern search may require an extensive amount of time to develop methods that correspond to the data scientist's reasoning, in order to solve their queries. The development of new methods, tightly related with the reasoning and visual analysis of time series data, is of great relevance to improving complexity and productivity of pattern and query search tasks. In this work, we propose a novel tool, capable of exploring time series data for pattern and query search tasks in a set of 3 symbolic steps: Pre-Processing, Symbolic Connotation and Search. The framework is called SSTS (Symbolic Search in Time Series) and uses regular expression queries to search the desired patterns in a symbolic representation of the signal. By adopting a set of symbolic methods, this approach has the purpose of increasing the expressiveness in solving standard pattern and query tasks, enabling the creation of queries more closely related to the reasoning and visual analysis of the signal. We demonstrate the tool's effectiveness by presenting 9 examples with several types of queries on time series. The SSTS queries were compared with standard code developed in Python, in terms of cognitive effort, vocabulary required, code length, volume, interpretation and difficulty metrics based on the Halstead complexity measures. The results demonstrate that this methodology is a valid approach and delivers a new abstraction layer on data analysis of time series.publishersversionpublishe

Heart rate and technical responses to variation in pitch dimension and surface in ‘‘three-a-side’’ youth soccer drills

Small-sided soccer games allow increasing players specific practice time eliciting simultaneously phy- sical and technical aspects within a major tactical involvement. Youth players’ performance in ‘‘three- a-side’’ drills are used very often without knowing their real impact. Thus, the aim of the current study was to identify heart rate and technical responses to variation in pitch dimension (30620 m; 20615 m) and surface (grass; rough sand) in ‘‘three-a-side’’ drills performed by youth players (age 9.9+0.64). Each drill condition lasted for 15 min, with a 6-min period of active recovery. Heart rate was evaluated through heart rate reserve (HRR). Tech- nical analysis was validated by a group of experts and consisted of quantifying the following variables: number and ratio of right and wrong passes, average number of ball contacts for each team’s ball possession, number of in and off goal shoots, goals, shooting efficiency, number of passes by shooting play and 161 situations. Results were analysed though a 262 repeated measures ANOVA. In the grass pitch, teams’ exhibited in the 30620 m pitch a higher HRR (132 + 5 and 126 + 4) and a higher ratio of right passes (0.72 + 0.01 and 0.60 + 0.03). In the rough sand pitch, significant differences were found, with higher values for the 30620 pitch, for number (49.5 + 0.7 and 39.0 + 2.8) and ratio (0.67 + 0.00 and 0.57 + 0.02) of right passes, average number of ball contacts (2.1 + 0.08 and 1.8 + 0.02) and HRR (129 + 5 and 124 + 4). In the 30620 m pitch, significant differences were found for ratio of right passes, with higher value in the grass (0.72 + 0.01 and 0.67 + 0.00), and HRR, also with higher values for the grass (134+4 and 129+5). In the 20615 m pitch, significant differences were found only in HRR, with higher values for the grass field (128+4 and 124+4). Coaches should be aware that modifying pitches dimension and surface influences drill physio- logical and technical impact. Therefore, these results help coaches to better plan and direct youth soccer drills and controlling quantity and quality in prac- tices

Towards Knowledge Uncertainty Estimation for Open Set Recognition

POCI-01-0247-FEDER-033479Uncertainty is ubiquitous and happens in every single prediction of Machine Learning models. The ability to estimate and quantify the uncertainty of individual predictions is arguably relevant, all the more in safety-critical applications. Real-world recognition poses multiple challenges since a model's knowledge about physical phenomenon is not complete, and observations are incomplete by definition. However, Machine Learning algorithms often assume that train and test data distributions are the same and that all testing classes are present during training. A more realistic scenario is the Open Set Recognition, where unknown classes can be submitted to an algorithm during testing. In this paper, we propose a Knowledge Uncertainty Estimation (KUE) method to quantify knowledge uncertainty and reject out-of-distribution inputs. Additionally, we quantify and distinguish aleatoric and epistemic uncertainty with the classical information-theoretical measures of entropy by means of ensemble techniques. We performed experiments on four datasets with different data modalities and compared our results with distance-based classifiers, SVM-based approaches and ensemble techniques using entropy measures. Overall, the effectiveness of KUE in distinguishing in- and out-distribution inputs obtained better results in most cases and was at least comparable in others. Furthermore, a classification with rejection option based on a proposed combination strategy between different measures of uncertainty is an application of uncertainty with proven results.publishersversionpublishe

Uncertainty-Based Rejection in Machine Learning: Implications for Model Development and Interpretability

POCI-01-0247-FEDER-033479Uncertainty is present in every single prediction of Machine Learning (ML) models. Uncertainty Quantification (UQ) is arguably relevant, in particular for safety-critical applications. Prior research focused on the development of methods to quantify uncertainty; however, less attention has been given to how to leverage the knowledge of uncertainty in the process of model development. This work focused on applying UQ into practice, closing the gap of its utility in the ML pipeline and giving insights into how UQ is used to improve model development and its interpretability. We identified three main research questions: (1) How can UQ contribute to choosing the most suitable model for a given classification task? (2) Can UQ be used to combine different models in a principled manner? (3) Can visualization techniques improve UQ’s interpretability? These questions are answered by applying several methods to quantify uncertainty in both a simulated dataset and a real-world dataset of Human Activity Recognition (HAR). Our results showed that uncertainty quantification can increase model robustness and interpretability.publishersversionpublishe

Single camera analyses in studying pattern forming dynamics of player interactions in team sports.

A network of patterned interactions between players characterises team ball sports. Thus, interpersonal coordination patterns are an important topic in the study of performance in such sports. A very useful method has been the study of inter-individual interactions captured by a single camera filming an extended performance area. The appropriate collection of positional data allows investigating the pattern forming dynamics emerging in different performance sub-phases of team ball sports. This chapter outlines (i) a simple and flexible motion analysis procedure to capture the movement displacement trajectories of performers using a single camera and, (ii) exemplar data illustrating the analysis methods employed in the identification of pattern forming dynamics in a 3vs3 sub-phase of association football near the scoring areas