1,721,002 research outputs found
Muscle mechanical work in walker-assisted locomotion: Instrumentationand modelling for an integrated gait analysis in cerebral palsy
Full text linkLa stima del lavoro meccanico muscolare è un utile strumento per valutare l'efficienza di un movimento, ma il processo di calcolo presenta ancora molte criticità dal punto di vista biomeccanico.
Diversi metodi per stimare il lavoro meccanico muscolare durante il cammino sono stati presentati in letteratura, ma nonostante i tentativi fatti per confrontarli, tutti i metodi sono tuttora utilizzati in ambito di ricerca e in ambito clinico. Una più profonda comprensione delle differenze, sia dal punto di vista teorico, che pratico, potrebbe permettere di capire cosa venga effettivamente calcolato da ciascun metodo ed aiutare a fare un uso più appropriato di questa informazione. A questo scopo è stato validato un modello tridimensionale a corpo completo, consistente in 16 segmenti, utilizzato per raccogliere informazioni cinematiche e dinamiche durante il cammino in ragazzi e bambini sani e in ragazzi e bambini affetti da paralisi cerebrale infantile (CP), camminati a velocità spontanea.
Lo sviluppo di due maniglie strumentate fissabili sulla struttura di deambulatori pediatrici posteriori ha permesso di misurare cinematica e dinamica dell'arto superiore anche in soggetti con maggiori difficoltà di deambulazione. Curve di potenza e valori di lavoro meccanico muscolare totale, positivo, negativo o netto, durante cammino normale e durante cammino con deambulatore, sono stati stimati dimostrando che tutti i metodi sono equivalenti quando vengono permessi trasferimenti di energia tra segmenti. Senza possibilità di trasferimento di energia, i metodi differiscono tra loro, con differenze dipendenti dal metodo utilizzato e dal movimento studiato. Eccetto alcune criticità evidenziate e discusse, l'analisi delle curve di potenza muscolare e dei valori di lavoro meccanico muscolare stimati può fornire utili informazioni sulla funzione locomotoria nel suo complesso, mettendo in luce deficit di propulsione, asimmetrie del cammino, inefficienze di movimento associate ad una ridotta capacità di recupero di energia.The estimation of muscle mechanical work can be useful to assess movement efficiency, but it is still a challenging task in biomechanics. Different methods to estimate muscle work during walking have been presented in the literature and, although attempts have been made to investigate differences among them, all methods are still used in research and clinical applications. A deeper understanding of theoretical differences and analogies would allow to know what is exactly computed by each method and help to make a more appropriate use of this information. To this purpose, a 16 segments full-body 3D model was validated and used to collect kinematic and kinetic data from healthy children and cerebral palsy (CP) children walking at self-selected speed. Two instrumented handles fixable on the frame of posterior paediatric walkers were also developed, to measure upper limb kinetics in subjects with more severe walking impairements. Whole-body muscle mechanical power curves and work values, either positive, negative or net, during normal gait and during walker locomotion were obtained, demonstrating that all methods
are equivalent when energy transfers between segments are allowed. With no transfers allowed, methods differ among each other, with differences depending on the movements and the methods considered. Apart from some critical issues evidenced and discussed, the analysis of whole-body muscle mechanical power curves and work estimates can provide valuable information on the overall locomotion function, highlighting propulsive deficits, gait asymmetries, movement inefficiencies associated to reduced energy recuperation
Interplanetary pit stops: Harnessing asteroids as solar filling stations for Earth-to-Mars missions
No full textThis paper studies Earth–Mars missions that utilize asteroid candidates as intermediate stops to perform in-situ resource utilization refueling and minimize overall spacecraft launch mass from Earth. The first leg of the trajectory intercepts one such asteroid candidate, where the spacecraft performs an insertion into a Sun–asteroid distant retrograde orbit. After refueling, the spacecraft transfers from the asteroid to Mars. While heliocentric orbital transfers are computed using Lambert’s problem, particle swarm optimization and dynamical systems theory are used to compute the proposed Sun–asteroid distant retrograde orbit and to determine the DV-optimal trajectories to approach and land onto the asteroid. The selection process for candidate asteroids narrows down from over a million possibilities to 94 asteroids based on specific orbital parameters. Significant DV savings and mission cost reductions are demonstrated through strategic asteroid selection. A double-arc trajectory model between Earth, an asteroid, and Mars is outlined, addressing computational challenges by dividing the problem into subdomains. The development of Sun–asteroid distant retrograde orbit families and the optimization of landing trajectories on selected asteroids using particle swarm optimization highlight the feasibility and advantages of asteroid-based refueling stations for sustainable space exploration
Sustainability and Digital Transformation as key drivers in pharma and healthcare M&A deals during covid-19 pandemic
No full textEnhancing decision-making with data-driven insights in critical situations: impact and implications of AI-powered predictive solutions
Full text linkIdentifying early signals of crisis or insolvency is essential, for firms, to enable timely
interventions, preserve financial health, and sustain competitive advantage. Traditional financial
models, while foundational in this domain, often fall short in complex environments and there is a
widening gap between the theoretical advancements in predictive modeling and their practical
application in real-world decision-making, particularly for small and medium-sized enterprises, that
may lack the resources to implement sophisticated risk management tools. Considering the Italian
business landscape, this research examines the integration of advanced AI-driven techniques,
showcasing their ability to handle vast and diverse data sources while improving predictive accuracy.
By employing an inductive, multi-layered approach to model implementation and refinement, the
study demonstrates how AI-based models can identify early indicators of distress up to five years before
insolvency, thus providing a robust framework for preventive strategies. A key added value is the focus
on enhancing explainability and understandability within AI models, delivering critical insights for
both academia and managers; by improving transparency, these models not only strengthen predictive
capacity but also enable stakeholders to better understand and interpret the drivers of financial and
economic distress.
Furthermore, the study highlights the challenges of adopting new technologies in
organizational contexts, addressing issues such as data ethics, managerial literacy, over-reliance risks
and the alignment of AI-based decision tools with regulatory standards. The findings contribute both
to academic discourse and practical applications by advocating for a cultural shift toward data-driven
decision-making in critical phases of business life; by balancing the precision of Machine Learning with
the interpretability required for managerial planning, it is underscored that, while AI just complements
human expertise, it is, today, instrumental in surviving in complex economic landscapes with greater
foresight and resilience
Corporate social responsibility and financial performance: An empirical analysis of the Italian case
No full textInvestigating ankle dynamics during walking on a subject with bilateral ankle arthroplasty
Full text linkAnkle dynamics during walking was investigated on a subject with bilateral ankle arthroplasty via computing muscle power and work produced by each of the two legs during the double support phases, and by analyzing the angle-moment hysteresis characteristics at the ankle, to highlight the different energy production/absorption phases at the two ankles
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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