1,721,009 research outputs found
An adaptive gait planner for a lower-limb exoskeleton ascending staircases of unknown geometry
No full textThe staircase ascent motion is a physical activity which is very common in everyday life, but it is very challenging for people who suffer for Spinal Cord Injury (SCI). Active exoskeletons can help patients to regain a certain degree of mobility, but their design require facing some difficult problems: smart exoskeletons need to perceive the environment and, in turn, adapt the gait, so as to guarantee a smooth and safe motion. In such a context, this work proposes a solution for a staircase ascending problem. It exploits low cost ranging sensors for the environment reconstruction and a real-time trajectory planner for the generation of an adaptive gait which accounts for the steps geometry. The strength of the proposed technique is represented by the continuous update method -- adopted for both the environment reconstruction and the path planning -- which allows for a safe ascent. The proposed method was tested through simulations and real experiments
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
Spectral Analysis Of The 4d95d And 4d95f Configurations In Octuple Ionization Of Xenon, Xe Ix
No full textA capillary light source was used to observe the spectrum of eight times-ionized xenon, Xe IX, in the vacuum ultraviolet range, 270-1300 Å. One hundred and nine transitions have been identified as combinations between levels of the 4d95d with 4d95p and 4d95f configuration. Seventeen levels have been determined that belong to the 4d95d configuration, and 15 belong to the 4d95f configuration. The energy parameters were obtained with Hartree-Fock relativistic calculations. Least-squares parametric calculation has been carried out to study the fit between experimental and theoretical values. © 2002 Elsevier Science Ltd. All rights reserved.7311322Martinson, I., (1989) Rep Prog Phys, 52, pp. 157-225Mueller, D.W., Wang, L.J., Gregory, D.C., (1989) Phys Rev A, 39, pp. 2381-2384van Kampen, P., Hallin, R., Heijkenskjöld, F., Langereis, A., Larsson, M.O., Nording, C., Nyström, B., Wännstrom, A., (1994) Phys Scr, 49, pp. 198-200van Kleef, T., Joshi, Y.N., Uijlings, P., (1980) Phys Scr, 22, pp. 353-362van Kleef, T., Joshi, Y.N., (1981) Phys Scr, 24, pp. 557-565Joshi, Y.N., van Kleef, T., (1979) Can J Phys, 57, pp. 1982-1989Bogdanovich, P., Martinson, I., (1999) Phys Scr, 60, pp. 217-221Gallardo, M., Raineri, M., Callegari, F., Reyna Almandos, J.G., (1995) Proceedings of the Fifth Latin-American Meeting on Optics, Lasers and Their Applications, pp. 94-97. , La Habana, CubaChurilov, S.S., Joshi, Y.N., Ryabtsev, A.N., (1994) J Phys B, 27, pp. 5485-5495Lemoff, B.E., Yin, G.Y., Gordon C.L. III, Barty, C.P.J., Harris, S.E., (1996) J Opt Soc Am B, 13, pp. 180-184Gallardo, M., Bredice, F., Raineri, M., Reyna Almandos, J.G., (1989) Appl Opt, 28, pp. 4513-4515Cowan, R.D., (1981) The Theory of Atomic Structure and Spectra, , Berkley, CA: University of California Pres
Second line systemic therapies for hepatocellular carcinoma: Reasons for the failure
Full text linkHepatocellular carcinoma (HCC) is the main cause of death in patients with cirrhosis, with an increasing incidence worldwide. Sorafenib is the choice therapy for advanced HCC. Over time several randomized phase ? trials have been performed testing sunitinib, brivanib, linifanib and other molecules in head-tohead comparison with Sorafenib as first-line treatment for advanced-stage HCC, but none of these has so far been registered in this setting. Moreover, another feared vacuum arises from the absence of molecules registered as second-line therapy for patients who have failed Sorafenib, representing an urgent unmet medical need. To date all molecules tested as second-line therapies for advanced hepatocellular carcinoma, failed to demonstrate an increased survival compared to placebo. What are the possible reasons for the failure? What we should expect in the near future
Generation of an adaptive ascending step for a lower limb exoskeleton
No full textAssistive exoskeletons are medical devices typically designed to perform repetitive movements. Recent researches highlighted the necessity to endow such devices with perceptual capabilities, in order to perform adaptive movements. This would allow using exoskeletons in everyday activities such as, for example, the ascent of a staircase. This work addresses some of the typical problems related to the motion along a staircase of a lower limb exoskeleton. In particular, the focus will be posed on problems such as the identification of the staircase and the relative position between them and the exoskeleton, the motion planning for the ascending foot and its adaptation to the changes of the torso orientation. The proposed strategies have been experimentally verified and the results are documented through videos
Genotipizzazione delle lattoproteine bovine mediante isoelettrofocalizzazione e PCR allele specifica bidirezionale (BAS-PCR)
No full textVariations 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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