Francesco Sgrò

A wireless traffic smoother for soft real-time communications over IEEE 802.11 industrial networks

This paper addresses the problem of supporting soft real-time traffic over IEEE 802.11 wireless local area networks in the presence of competing non-real-time traffic. The proposed solution is a wireless traffic smoother (WTS) which uses as inputs the throughput and the number of frame retransmissions at the MAC level. Combining these two inputs, the WTS is able to adapt the smoothing action to the current wireless network condition. The paper discusses the WTS, also highlighting the way it advances the current state of the art. Then, the WTS performance obtained from experiments performed on a real testbed, also in comparison to another approach recently proposed in the literature, is discussed.

Assessing Vertical Jump Developmental Levels in Childhood Using a Low-Cost Motion Capture Approach

Understanding the developmental levels of fundamental movement skills has a critical role in the improvement of motor competence in childhood. In this respect, the use of Microsoft Kinect to assess vertical jumping skill and to predict developmental levels in 9- to 12-yr.-old children was evaluated. 41 boys and girls repeated the countermovement jump test three times. Vertical jumping skill levels were categorized using observational records, while kinematic and temporal parameters were estimated using a biomechanical model based on data acquired by the Kinect. Multivariate analysis of variance (MANOVA) and discriminant analysis verified that the height of the jump and the flight height predict the primary differences in jumping skill developmental levels, and the Kinect-based assessment discriminates these levels.

Small-Sided Games and Technical Skills in Soccer Training: Systematic Review and Implications for Sport and Physical Education Practitioners

High-level of technical skills and tactical behaviour are key factors for an optimal performance in soccer games. About the most used and innovative training methods, the small-sided games (SSGs) seem to be a worthy and valid methodology to train simultaneously many skills by reproducing several conditions of a real match. Accordingly, the aim of this study was to conduct a systematic review of the available literature to lead an improved understanding in the usefulness of SSGs for improving technical skills in soccer. To ensure a rigorous and reliable approach, the review was performed according to PRISMA (Preferred Reporting Items for Systematic review and Meta-analyses) guidelines. 1031 records were initially identified, but only 26 studies were further included in the review. Moreover, other two studies were added after a check of the bibliography of two major reviews. So, each of these studies was analysed according to the aforementioned guidelines and using inclusion criteria related to SSG and training in soccer. The current analysis provided several indications and recommendations for coaches and trainers of soccer teams in order to improve several technical skills by means of the use of SSGs. Furthermore, several evidences for using SSGs in school environment are also provided.

A networked embedded computing platform for physical activity assessment

This paper proposes a networked embedded computing platform for wearable telemedicine especially devised to obtain an objective, accurate and non-invasive assessment of physical activity. The platform here proposed realizes a tradeoff between feasibility and accuracy of the measurements. The proposed platform can be easily used by both athletes and researchers/clinicians interested in the assessment of people physical performance.

Assessing Standing Long Jump Developmental Levels Using an Inertial Measurement Unit

This study tested the feasibility of using an inertial measurement unit to discriminate different developmental levels of children performing the standing long jump (SLJ). Sixty-four children (54.6% boys, 46.4% girls) aged 8 to 11 years old (M = 9.17, SD = 0.97) performed the SLJ three times and were classified by rater observations into three developmental levels. Concurrently, they wore an inertial measurement unit from which a set of temporal and kinematic parameters for the quantitative assessment of their jumps. A multivariate analysis of variance revealed that variability among the developmental groups was identified by the overall set of parameters, while discriminant function analysis verified that these parameters discriminated among developmental levels. Primary predictors for developmental group discrimination were maximum peak acceleration in the vertical and anteroposterior directions, respectively, and normalized preparation time. These outcomes represent significant steps toward improving the assessment of SLJ rate of development in childhood and supporting physical education.

Offensive strategies in the European Football Championship 2012

The aim of this study was to identify the independent and interactive effects of possession strategy, pitch location, and game period on the offensive actions performed by the winning teams in the 2012 European Football Championship. The non-clinical magnitude-based inferences method was used to interpret the true effect of the performance indicators on the response variable. The offensive team possessions were grouped into winning (n = 2035) and losing (n = 2071). The winning teams performed offensive processes mainly using the possession play strategy (OR: 0.75, very likely negative effect of the direct play). When the analysis included the pitch location, negative interaction effect was found for the direct play, which ended up in the central path (OR: 0.70, very likely negative effect). On the contrary, the direct play in the second half of the match seemed to produce an effect on the probability of the winning teams performing offensive processes (OR: 1.59, most likely positive effect). The results of multivariate analyses showed that the offensive team possession profiles required a careful investigation because the possession strategy changed under the conjoint effect of pitch location and game period.

A study on balance ability levels among youths with different physical activity background

Background: Balance is one of the primary abilities developed during the motor and skeletal evolution. Regular and specific training throughout life-span could improve the balance and, in turn the execution of complex motor patterns as well as of the normal daily activities (Ricotti, 2011). Aim: In this study we investigate the relation between the balance abilities and different types of physical activities (PA) in youths. Method: Thirty-six subjects (age: 24±17 years; male/female:18/18) were enrolled and grouped into two PA categories: the exergame group includes subjects who use Nintendo Wii Balance Board gaming at least twice a week (n=12), and the sport group includes subjects who practice sport at least twice a week (n=12). Subjects who do not practice sports or physical activity were enrolled as control (n=12). The postural control was assessed by means of normal standing balance tests (for 30s) with open eyes (OE) and closed eyes (CE), respectively; a force plate (AMTI Model OR6-7) was used to acquire data of the centre of pressure (CoP) sway. According to previous study [2], we were able to select two variables from CoP sway: the total displacement of sway (DOT) and the mean velocity. The mean velocity was estimated for anteroposterior (MV AP ) and lateral-lateral (MV LL ) directions, respectively. Statistical analysis was carried out with SPSS (SPSS Inc, Ver. 20). Significance of differences was assessed by one-way ANOVA followed by Bonferroni post-hoc test (95% confidence level). Result: ANOVA revealed significant differences among groups for the three variables. We found that the mean of DOT and MVAP was significantly decreased in the exergame’s group compared with the others study groups. Of note, the differences were higher for CE than OE test. Conclusion: Our findings suggest that the balance ability reaches a mastery level during the youth age-period. However, a specific program of balance training using the exergaming approach could improve the proficiency level of the aforementioned ability more than conventional sport training.