Adaptive synchronization of unknown heterogeneous agents: An adaptive virtual model reference approach

This work deals with state synchronization of heterogeneous linear agents with unknown dynamics. The problem is solved by formulating the synchronization problem as a special model reference adaptive control where each agent tries to converge to the model defined by its neighbors. For those agents that do not know the reference signal that drives the flock, a fictitious reference is estimated in place of the actual one: the estimation of such reference is distributed and requires measurements from neighbors. By using a matching condition assumption, which is imposed so that the agents can converge to the same behavior, the fictitious reference estimation leads to adaptive laws for the feedback and the coupling gains arising from distributed matching conditions. In addition, the coupling connection is not scalar as in most literature, but possibly vector-valued. The proposed approach is applicable to heterogeneous agents with arbitrarily large matched uncertainties. A Lyapunov-based approach is derived to show analytically asymptotic convergence of the synchronization error: robustification in the presence of bounded errors or unknown (constant) leader input is also discussed. Finally, a motivational example is presented in the context of Cooperative Adaptive Cruise Control and numerical examples are provided to demonstrate the effectiveness of the proposed method.     

Composite cooperative synchronization and decentralized learning of multi-robot manipulators with heterogeneous nonlinear uncertain dynamics

This paper studies the problem of composite synchronization and learning of multiple coordinated robot manipulators subject to heterogeneous nonlinear uncertain dynamics under the leader-follower framework. A new two-layer distributed adaptive learning control scheme is proposed, which consists of the first-layer distributed cooperative estimator and the second-layer decentralized deterministic learning controller. The first layer aims to enable each robotic agent to estimate the leader’s information. The second layer is responsible for not only controlling each individual robotic agent to track over desired reference trajectory, but also accurately identifying/learning each robot’s nonlinear uncertain dynamics. Design and implementation of this two-layer distributed controller can be carried out in a fully-distributed manner, which do not require any global information including global connectivity of the communication network. The Lyapunov method is applied to rigorously analyze stability and parameter convergence of the resulting closed-loop system. Numerical simulations on a team of two-degree-of-freedom robot manipulators have been conducted to demonstrate the effectiveness of the proposed results.     

Prevention of child abuse and neglect through early diagnosis of serious disturbances in the mother-child relationship in Italy

At the obstetrical clinic of Modena University and a family center of the same municipality during the first six months of 1980 a questionnaire based on "Risks of Child Abuse" by Kempe, Gray and others was administered to 33 expectant mothers during the third trimester of pregnancy, a few days after delivery, and a month and one-half after childbirth, for the purpose of examining the mother-child relationship. Two principal groups of "risk factors" which may lead to child abuse and neglect appeared: mothers with preceding personal and social experiences, and cases of medical intervention (e.g., prematurity, caesarean). Use of a questionnaire that permitted early diagnosis made possible help in establishing a good mother-child relationship in the first months of life. Such help can be given by the hospital and public centers both before and after birth.     

Beyond contact-tracing: The public value of eHealth application in a pandemic

This study adopts a public value perspective to examine the eHealth services deployed by national and regional governments to contain the coronavirus (Covid-19) pandemic, including symptoms checkers, information portals and contact-tracing applications. We analyse 50 cases of eHealth applications adopted in 25 European Economic Area (EEA) and outline how these systems and technologies map against four dimensions of public value: user orientation, participation, legality and equity. Our findings reveal that the public value of the eHealth applications adopted in the context of the current pandemic is affected by both endogenous and exogenous factors that undermine their ability to improve the quality of healthcare services and social wellbeing. We conclude by suggesting areas for further research to address such factors and the trade-offs emerging between different dimensions of public value.     

Bidirectional avoidance by mice as a function of CS,US, and apparatus variables

Acquisition of two-way avoidance by mice was slower with a light CS than with a buzzer CS, with punishment of intertrial responses than without punishment, and with a short CS-CS interval than with a long CS-CS interval (30 vs. 60 sec). Light-cued avoidance was little affected by shock level (.35–1.5 mA), whereas mice trained with the buzzer CS learned faster at 1.5 mA. Animals required to move away from light or toward light showed comparable rates of acquisition. Other CS, US, and apparatus variables (directionality of cue, maximal shock duration, and presence vs. absence of a central partition in the shuttlebox) interacted in a complex fashion with those already mentioned. This resulted in widely differing performances in what may superficially appear to be different versions of the same task. The differences in mouse and rat responses to some of the variables can contribute to an understanding of the interactions between organismic and test factors and the relative explanatory value of alternative avoidance models.     

Implementation of Web 2.0 services in academic, medical and research libraries: a scoping review

Background: Academic, medical and research libraries frequently implement Web 2.0 services for users. Several reports notwithstanding, characteristics and effectiveness of services are unclear. Objectives: To find out: the Web 2.0 services implemented by medical, academic and research libraries; study designs, measures and types of data used in included articles to evaluate effectiveness; whether the identified body of literature is amenable to a systematic review of results. Methods: Scoping review mapping the literature on the topic. Searches were performed in 19 databases. Inclusion criteria: research articles in English, Italian, German, French and Spanish (publication date ≥2006) about Web 2.0 services for final users implemented by academic, medical and research libraries. Reviewers’ agreement was measured by Cohen’s kappa. From a data set of 6461 articles, 255 (4%) were coded and analysed. Results: Conferencing/chat/instant messaging, blogging, podcasts, social networking, wikis and aggregators were frequently examined. Services were mainly targeted at general academic users of English‐speaking countries. Conclusions: Data prohibit a reliable estimate of the relative frequency of implemented Web 2.0 services. Case studies were the prevalent design. Most articles evaluated different outcomes using diverse assessment methodologies. A systematic review is recommended to assess the effectiveness of such services.     

A structural equation model predicting adults’ online learning self-efficacy

Education and Information Technologies - We aimed to model the direct effects of the theorized relationships of academic self-efficacy, computer use self-efficacy, learning management system...