In-Cylinder Pressure Estimation from Rotational Speed Measurements via Extended Kalman Filter.

Real-time estimation of the in-cylinder pressure of combustion engines is crucial to detect failures and improve the performance of the engine control system. A new estimation scheme is proposed based on the Extended Kalman Filter, which exploits measurements of the engine rotational speed provided by a standard phonic wheel sensor. The main novelty lies in a parameterization of the combustion pressure, which is generated by averaging experimental data collected in different operating points. The proposed approach is validated on real data from a turbocharged compression ignition engine, including both nominal and off-nominal working conditions. The experimental results show that the proposed technique accurately reconstructs the pressure profile, featuring a fit performance index exceeding 90% most of the time. Moreover, it can track changes in the engine operating conditions as well as detect the presence of cylinder-to-cylinder variations.

A remote lab for experiments with a team of mobile robots.

In this paper, a remote lab for experimenting with a team of mobile robots is presented. Robots are built with the LEGO Mindstorms technology and user-defined control laws can be directly coded in the Matlab programming language and validated on the real system. The lab is versatile enough to be used for both teaching and research purposes. Students can easily go through a number of predefined mobile robotics experiences without having to worry about robot hardware or low-level programming languages. More advanced experiments can also be carried out by uploading custom controllers. The capability to have full control of the vehicles, together with the possibility to define arbitrarily complex environments through the definition of virtual obstacles, makes the proposed facility well suited to quickly test and compare different control laws in a real-world scenario. Moreover, the user can simulate the presence of different types of exteroceptive sensors on board of the robots or a specific communication architecture among the agents, so that decentralized control strategies and motion coordination algorithms can be easily implemented and tested. A number of possible applications and real experiments are presented in order to illustrate the main features of the proposed mobile robotics remote lab.

Physical fitness of primary school children in relation to overweight prevalence and physical activity habits.

A cross-sectional study was carried out to analyse, through a limited number of fitness tests, the main conditioning and coordinative abilities in children aged 8-9 years, and their relationship with gender, anthropometric variables and physical activity habits. The height and weight of 256 boys and 241 girls were measured and information about physical activity habits was collected using a self-administered questionnaire. Physical performance was assessed by means of a few standardised tests: 'sit & reach', medicine-ball forward throw, standing long jump, 20 m running speed, and forward roll test. In both boys and girls, body weight and body mass index (BMI) were positively correlated with the medicine-ball throw performances and negatively correlated for the standing long jump and speed tests, while no association was found with tests measuring back flexibility and total body coordination. Daily physical activity and participation in sport were not significantly correlated with body weight and BMI, but were positively associated with children's motor performance. The standardised fitness tests selected in the current study have been found to be suitable to identify fitness levels of primary school children. Thanks to their limited number and ease of measurement, they can be used in any school context to classify children and for monitoring the effects of targeted interventions promoting physical activity.

Asynchronous Distributed Learning From Constraints.

In this brief, the extension of the framework of Learning from Constraints (LfC) to a distributed setting where multiple parties, connected over the network, contribute to the learning process is studied. LfC relies on the generic notion of "constraint" to inject knowledge into the learning problem, and, due to its generality, it deals with possibly nonconvex constraints, enforced either in a hard or soft way. Motivated by recent progresses in the field of distributed and constrained nonconvex optimization, we apply the (distributed) asynchronous method of multipliers (ASYMM) to LfC. The study shows that such a method allows us to support scenarios where selected constraints (i.e., knowledge), data, and outcomes of the learning process can be locally stored in each computational node without being shared with the rest of the network, opening the road to further investigations into privacy-preserving LfC. Constraints act as a bridge between what is shared over the net and what is private to each node, and no central authority is required. We demonstrate the applicability of these ideas in two distributed real-world settings in the context of digit recognition and document classification.

Off-line removal of TMS-induced artifacts on human electroencephalography by Kalman filter.

In this paper we present an off-line Kalman filter approach to remove transcranial magnetic stimulation (TMS)-induced artifacts from electroencephalographic (EEG) recordings. Two dynamic models describing EEG and TMS signals generation are identified from data and the Kalman filter is applied to the linear system arising from their combination. The keystone of the approach is the use of time-varying covariance matrices suitably tuned on the physical parameters of the problem that allow to model the nonstationary components of the EEG-TMS signal. This guarantees an efficient deletion of TMS-induced artifacts while preserving the integrity of EEG signals around TMS impulses. Experimental results show that the Kalman filter is more effective than stationary filters (Wiener filter) for the problem under investigation.

Walking Ahead: The Headed Social Force Model.

Human motion models are finding an increasing number of novel applications in many different fields, such as building design, computer graphics and robot motion planning. The Social Force Model is one of the most popular alternatives to describe the motion of pedestrians. By resorting to a physical analogy, individuals are assimilated to point-wise particles subject to social forces which drive their dynamics. Such a model implicitly assumes that humans move isotropically. On the contrary, empirical evidence shows that people do have a preferred direction of motion, walking forward most of the time. Lateral motions are observed only in specific circumstances, such as when navigating in overcrowded environments or avoiding unexpected obstacles. In this paper, the Headed Social Force Model is introduced in order to improve the realism of the trajectories generated by the classical Social Force Model. The key feature of the proposed approach is the inclusion of the pedestrians' heading into the dynamic model used to describe the motion of each individual. The force and torque representing the model inputs are computed as suitable functions of the force terms resulting from the traditional Social Force Model. Moreover, a new force contribution is introduced in order to model the behavior of people walking together as a single group. The proposed model features high versatility, being able to reproduce both the unicycle-like trajectories typical of people moving in open spaces and the point-wise motion patterns occurring in high density scenarios. Extensive numerical simulations show an increased regularity of the resulting trajectories and confirm a general improvement of the model realism.

Proposal for an Enhanced Physical Education Program in the Primary School: Evaluation of Feasibility and Effectiveness in Improving Physical Skills and Fitness.

BACKGROUND: A large proportion of children do not reach the recommended levels of physical activity for health. A quasiexperimental study with nonrandom assignment was performed to evaluate the effectiveness and feasibility of a school-based physical education intervention aimed at increasing the levels of moderate-to-vigorous physical activity (MVPA). METHODS: Ten classes from 4 primary schools, including 241 children aged 8 to 10 years, were recruited. The experimental group (n = 97) received 4 additional sessions/week of 60 minutes of MVPA for 8 months. The control group (n = 135) continued their standard program (2 sessions of 50 minutes/week). Motor abilities (standing long jump, handgrip strength, Harre circuit, sit and reach), physical fitness (Yo-Yo Intermittent Recovery Level-1), anthropometric measures (body mass index, waist to height ratio), and self-efficacy (Perceived Physical Ability Scale for Children) were evaluated at baseline and after the intervention. RESULTS: The experimental group significantly improved in the Harre circuit both in males (P < .001) and females (P < .01), whereas physical fitness test improved only in males (P < .001). Males in the experimental group improved the perception of self-efficacy in coordinative abilities (P = .017). CONCLUSIONS: The proposed school-based MVPA program showed effectiveness and feasibility. The differences observed by gender highlight the need to use different strategies to increase the involvement of all the participants.

Effects of a 2-year school-based intervention of enhanced physical education in the primary school.

BACKGROUND: This study aimed to assess whether a school-based physical education intervention was effective in improving physical abilities and influencing daily physical activity habits in primary school children. The possible effect on body mass index (BMI) was also considered. METHODS: Twenty-six 3rd-grade classes were randomly selected stratifying by geographic location (city, plain, hills) and were assigned either to an intervention (127 boys; 120 girls) or to a traditional (129 boys; 121 girls) physical education program. At baseline (age: 8-9 years) and after a 2-year follow-up (age: 10-11 years), information was collected about sport participation and daily activity habits using a self-administered questionnaire. Height, weight, and BMI were measured and physical performance was assessed by means of standardized tests. RESULTS: The enhanced program of physical education was effective in improving physical abilities of children and determining a decrease (boys: 10%; girls: 12%) in daily sedentary activities (preintervention versus postintervention, p < .05; intervention versus control group, p < .01). The percentages of overweight and obese children did not vary significantly, but the experimental group showed a significantly lower rise in BMI compared to the control group (p < .001). CONCLUSION: The school proved to be an ideal setting for promoting physical activity and achieving the required daily activity levels.