Large data and Bayesian modeling—aging curves of NBA players

Researchers interested in changes that occur as people age are faced with a number of methodological problems, starting with the immense time scale they are trying to capture, which renders laboratory experiments useless and longitudinal studies rather rare. Fortunately, some people take part in particular activities and pastimes throughout their lives, and often these activities are systematically recorded. In this study, we use the wealth of data collected by the National Basketball Association to describe the aging curves of elite basketball players. We have developed a new approach rooted in the Bayesian tradition in order to understand the factors behind the development and deterioration of a complex motor skill. The new model uses Bayesian structural modeling to extract two latent factors, those of development and aging. The interaction of these factors provides insight into the rates of development and deterioration of skill over the course of a player’s life. We show, for example, that elite athletes have different levels of decline in the later stages of their career, which is dependent on their skill acquisition phase. The model goes beyond description of the aging function, in that it can accommodate the aging curves of subgroups (e.g., different positions played in the game), as well as other relevant factors (e.g., the number of minutes on court per game) that might play a role in skill changes. The flexibility and general nature of the new model make it a perfect candidate for use across different domains in lifespan psychology

Kinetics and mechanism of synthetic CoS oxidation process

The results of investigation of kinetics and mechanism for synthetic a-CoS oxidation process are presented in this paper. Based on experimental data obtained using DTA and XRD analysis and constructed PSD diagrams for Co-S-O system, mechanism of synthetic a-CoS oxidation process is suggested. Characteristic kinetic parameters were obtained for experimental isothermal investigations of desulfurization degree using Sharp method

Reading the future from body movements – anticipation in handball

In speed-based sports that require fast reactions, the most accurate predictions are made once the players have seen the ball trajectory. However, waiting for the ball trajectory does not leave enough time for appropriate reactions. Expert athletes use kinematic information which they extract from the opponent’s movements to anticipate the ball trajectory. Temporal occlusion, where only a part of the full movement sequence is presented, has often been used to research anticipation in sports. Unlike many previous studies, we chose occlusion points in video-stimuli of penalty shooting in handball based on the domain-specific analysis of movement sequences. Instead of relying on randomly chosen occlusion points, each time point in our study revealed a specific chunk of information about the direction of the ball. The multivariate analysis showed that handball goalkeepers were not only more accurate and faster than novices overall when predicting where the ball will end up, but that experts and novices also made their decisions based on different kinds of movement sequences. These findings underline the importance of kinematic knowledge for anticipation, but they also demonstrate the significance of carefully chosen occlusion points

Thermodynamic and Structural Investigation of the Ag-In-Sb System

The Ag-In-Sb ternary system presents one of the possible lead-free solder candidates. Therefore, the results of thermodynamic study of the alloys in the Ag-In-Sb alloys, obtained using general solution model, are presented in the paper. Obtained data for partial and integral molar thermodynamic quantities in the temperature interval 1000-1200K are given. The characterization of these alloys have been done using DTA, XRD, SEM and optic microscopy, which enabled the construction of the Ag-In-Sb phase diagram in the concentration range up to 60 wt. % Ag

Large data and Bayesian modeling—aging curves of NBA players

Researchers interested in changes that occur as people age are faced with a number of methodological problems, starting with the immense time scale they are trying to capture, which renders laboratory experiments useless and longitudinal studies rather rare. Fortunately, some people take part in particular activities and pastimes throughout their lives, and often these activities are systematically recorded. In this study, we use the wealth of data collected by the National Basketball Association to describe the aging curves of elite basketball players. We have developed a new approach rooted in the Bayesian tradition in order to understand the factors behind the development and deterioration of a complex motor skill. The new model uses Bayesian structural modeling to extract two latent factors, those of development and aging. The interaction of these factors provides insight into the rates of development and deterioration of skill over the course of a player’s life. We show, for example, that elite athletes have different levels of decline in the later stages of their career, which is dependent on their skill acquisition phase. The model goes beyond description of the aging function, in that it can accommodate the aging curves of subgroups (e.g., different positions played in the game), as well as other relevant factors (e.g., the number of minutes on court per game) that might play a role in skill changes. The flexibility and general nature of the new model make it a perfect candidate for use across different domains in lifespan psychology

Physico-chemical characterization of slag occurrences at Tilva Njagra locality, Bor region, Eastern Serbia

Physico-chemical characterization of slag occurrences at Tilva Njagra locality (Bor region, Eastern Serbia) was done and the results of the research activities are presented in this paper. The samples were investigated using chemical analysis, XRD, DTA and EDXRF

Investigation of archaeometallurgical findings from Felix Romuliana locality

Remains of metallurgical activities have been discovered recently at the locality Felix Romuliana near Zaječar (Eastern Serbia), with a lot of slag occurrences and metal findings. Samples, taken from this locality, have been investigated using different characterization methods - chemical analysis, XRD and SEM-EDX, in order to clarify the Early Byzantine metallurgical activities at Felix Romuliana