1,720,963 research outputs found
A priori estimates and large population limits for some nonsymmetric Nash systems with semimonotonicity
Full text linkWe address the problem of regularity of solutions (Formula presented.) to a family of semilinear parabolic systems of (Formula presented.) equations, which describe closed-loop equilibria of some (Formula presented.) -player differential games with Lagrangian having quadratic behaviour in the velocity variable, running costs (Formula presented.) and final costs (Formula presented.). By global (semi)monotonicity assumptions on the data (Formula presented.) and (Formula presented.), and assuming that derivatives of (Formula presented.) in directions (Formula presented.) are of order (Formula presented.) for (Formula presented.), we prove that derivatives of (Formula presented.) enjoy the same property. The estimates are uniform in the number of players (Formula presented.). Such a behaviour of the derivatives of (Formula presented.) arise in the theory of Mean Field Games, though here we do not make any symmetry assumption on the data. Then, by the estimates obtained we address the convergence problem (Formula presented.) in a ‘heterogeneous’ Mean Field framework, where players all observe the empirical measure of the whole population, but may react differently from one another. We also discuss some results on the joint (Formula presented.) and vanishing viscosity limit
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
On mobility and gait in scoliosis patients: a comparison of conventional and 3D-printed braces during an instrumented timed-up and go test
Full text linkObjectiveSpinal orthoses are the most viable conservative treatment for scoliosis, and additive manufacturing techniques have shown huge perspective in producing patient-specific braces, reducing material waste, and production times. This pilot study aimed at determining whether 3D-printed braces could induce advantages or disadvantages compared to conventional braces in terms of mobility and gait, and at quantitatively evaluating the effects of braces on mobility and gait.MethodsTen participants were included in the study, eight with adolescent idiopathic scoliosis and two with osteogenesis imperfecta. Participants were asked to perform Timed-Up and Go (TUG) tests wearing a triaxial accelerometer under three conditions: unbraced, wearing a conventional (i.e., thermoformed) brace, and wearing a 3D-printed brace. After segmenting each TUG test in sub-phases, metrics quantifying gait and mobility were computed, and Friedman tests among all conditions were performed.ResultsNo significant differences in scoliotic patients mobility and gait between conventional and 3D-printed brace conditions were found, potentially suggesting that 3D-printed braces are as effective as conventional ones. Conversely, Stand flexion amplitude and Sit extension amplitude were lower in both conventional and 3D-printed brace conditions compared to the unbraced, meaning that braces limited the trunk range of motion. As for gait parameters, no significant differences in Walk Cadence and Walk Velocity among the three conditions were found, indicating that braces did not affect gait, at least during TUG tests.Trial registrationThe study was registered at Clinicaltrials.gov (Study ID NCT04282408, Date of Registration February 11th, 2020)
Comparison of geometrical accuracy of active devices for 3D orthopaedic reconstructions
Full text linkThe use of 3D digitizing tools is becoming the base for subject-specific products, such as the orthopaedic production process of orthoses and prostheses. This paper aims at comparing the metrological behaviour of low-cost devices (Kinect 1 and 2 by Microsoft, Structure Sensor by Occipital) and high-resolution active sensors (O&P Scan by Rodin4D, NextEngine Ultra HD, Konica Minolta Vivid 9i, GOM ATOS II 400 and Artec Leo) for the survey of human body parts. A calibrated flat plane and a test-field composed of eight calibrated spheres of different radii and placed at different heights were used to evaluate the standard quality parameters (flatness, probing errors in form and size and the standard deviation) for each device as recommended by the VDI/VDE 2634 guidelines. Subsequently, three different parts of a mannequin were surveyed as samples of human body parts. The results demonstrated the higher accuracy of fixed devices with respect to handheld ones, among which Artec Leo and Structure Sensor provided a satisfying level of accuracy for the orthopaedic application. Moreover, the handheld devices enabled performing a fast reconstruction of the mannequin parts in about 20 s, which is acceptable for a person that has to remain as still as possible. For this reason, the Structure Sensor was further tested with five motion approaches which identified that smooth motion provides the lowest deviation and higher reliability. The work demonstrated the appropriateness of handheld devices for the orthopaedic application requirements in terms of speed, accuracy and costs
Comparison of geometrical accuracy of active devices for 3D orthopaedic reconstructions
No full textThe use of 3D digitizing tools is becoming the base for subject-specific products, such as the orthopaedic production process of orthoses and prostheses. This paper aims at comparing the metrological behaviour of low-cost devices (Kinect 1 and 2 by Microsoft, Structure Sensor by Occipital) and high-resolution active sensors (O&P Scan by Rodin4D, NextEngine Ultra HD, Konica Minolta Vivid 9i, GOM ATOS II 400 and Artec Leo) for the survey of human body parts. A calibrated flat plane and a test-field composed of eight calibrated spheres of different radii and placed at different heights were used to evaluate the standard quality parameters (flatness, probing errors in form and size and the standard deviation) for each device as recommended by the VDI/VDE 2634 guidelines. Subsequently, three different parts of a mannequin were surveyed as samples of human body parts. The results demonstrated the higher accuracy of fixed devices with respect to handheld ones, among which Artec Leo and Structure Sensor provided a satisfying level of accuracy for the orthopaedic application. Moreover, the handheld devices enabled performing a fast reconstruction of the mannequin parts in about 20 s, which is acceptable for a person that has to remain as still as possible. For this reason, the Structure Sensor was further tested with five motion approaches which identified that smooth motion provides the lowest deviation and higher reliability. The work demonstrated the appropriateness of handheld devices for the orthopaedic application requirements in terms of speed, accuracy and costs
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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