101,884 research outputs found
The p- and hp-versions of the virtual element method for elliptic eigenvalue problems
No full textWe discuss the p- and hp-versions of the virtual element method for the approximation of eigenpairs of elliptic operators with a potential term on polygonal meshes. An application of this model is provided by the Schrödinger equation with a pseudo-potential term. As an interesting byproduct, we present for the first time in literature an explicit construction of the stabilization of the mass matrix. We present in detail the analysis of the p-version of the method, proving exponential convergence in the case of analytic eigenfunctions. The theoretical results are supplied with a wide set of experiments. We also show numerically that, in the case of eigenfunctions with finite Sobolev regularity, an exponential approximation of the eigenvalues in terms of the cubic root of the number of degrees of freedom can be obtained by employing hp-refinements. Importantly, the geometric flexibility of polygonal meshes is exploited in the construction of the hp-spaces
The - and -versions of the virtual element method for elliptic eigenvalue problems
No full textWe discuss the p- and hp-versions of the virtual element method for the approximation
of eigenpairs of elliptic operators with a potential term on polygonal meshes. An
application of this model is provided by the Schrödinger equation with a pseudo-
potential term. As an interesting by product, we present for the first time in literature
an explicit construction of the stabilization of the mass matrix. We present in detail
the analysis of the p-version of the method, proving exponential convergence in the
case of analytic eigenfunctions. The theoretical results are supplied with a wide set
of experiments. We also show numerically that, in the case of eigenfunctions with
finite Sobolev regularity, an exponential approximation of the eigenvalues in terms of
the cubic root of the number of degrees of freedom can be obtained by employing
hp-refinements. Importantly, the geometric flexibility of polygonal meshes is exploited
in the construction of the hp-spaces
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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3346: Samuel G. Freedman, author, 2013
No full textPhotograph of author Samuel G. Freedman, at NT Daily Slash meeting in the Mayborn School of Journalism at UNT
SEMG-biofeedback armband for hand motor rehabilitation in stroke patients: A preliminary pilot longitudinal study
No full textUpper limb motor impairment is one of the most debilitating sequelae after stroke, thus the aim of rehabilitation is to promote functional recovery and improve quality of life. Surface Electromyography Biofeedback (sEMG-BFB) is a therapeutic tool based on providing amplified neuromuscular information on motor performance to the patient, for enhancing motor learning and driving to a successful recovery. A preliminary pilot longitudinal study was carried out to preliminarily investigate any clinical and instrumental effect due to an innovative treatment based on sEMG-BFB, in stroke survivors. Fifteen stroke patients with impairment of hand function were enrolled for a 3-weeks- training with REcognition MOvement (REMO®), a sEMG-BFB armband, clinical and instrumental assessments were administered before and after the training. After training, statistically significant differences were observed at the Box and Block Test (BBT) and in the relation between changes at BBT and chMAX-chMIN of wrist extension movement. Our results indicated that improvement in the device control is associated to a better hand function. Further studies need to be conducted to investigate the feasibility of using REMO® to study motor behavior in both healthy and diseased subjects
Understanding Oxygen Release from Nanoporous Perovskite Oxides and Its Effect on the Catalytic Oxidation of CH4and CO
No full textThe design of nanoporous perovskite oxides is considered an efficient strategy to develop performing, sustainable catalysts for the conversion of methane. The dependency of nanoporosity on the oxygen defect chemistry and the catalytic activity of perovskite oxides toward CH4 and CO oxidation was studied here. A novel colloidal synthesis route for nanoporous, high-temperature stable SrTi0.65Fe0.35O3-δ with specific surface areas (SSA) ranging from 45 to 80 m2/g and pore sizes from 10 to 100 nm was developed. High-temperature investigations by in situ synchrotron X-ray diffraction (XRD) and TG-MS combined with H2-TPR and Mössbauer spectroscopy showed that the porosity improved the release of surface oxygen and the oxygen diffusion, whereas the release of lattice oxygen depended more on the state of the iron species and strain effects in the materials. Regarding catalysis, light-off tests showed that low-temperature CO oxidation significantly benefitted from the enhancement of the SSA, whereas high-temperature CH4 oxidation is influenced more by the dioxygen release. During isothermal long-term catalysis tests, however, the continuous oxygen release from large SSA materials promoted both CO and CH4 conversion. Hence, if SSA maximization turned out to efficiently improve low-temperature and long-term catalysis applications, the role of both reducible metal center concentration and crystal structure cannot be completely ignored, as they also contribute to the perovskite oxygen release properties
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