Search results for "NUMB"
showing 10 items of 3956 documents
Clarkson-McCarthy inequalities with unitary and isometry orbits
2020
Abstract A refinement of a trace inequality of McCarthy establishing the uniform convexity of the Schatten p-classes for p > 2 is proved: if A , B are two n-by-n matrices, then there exists some pair of n-by-n unitary matrices U , V such that U | A + B 2 | p U ⁎ + V | A − B 2 | p V ⁎ ≤ | A | p + | B | p 2 . A similar statement holds for compact Hilbert space operators. Another improvement of McCarthy's inequality is given via the new operator parallelogramm law, | A + B | 2 ⊕ | A − B | 2 = U 0 ( | A | 2 + | B | 2 ) U 0 ⁎ + V 0 ( | A | 2 + | B | 2 ) V 0 ⁎ for some pair of 2n-by-n isometry matrices U 0 , V 0 .
Is the long-run underperformance of seasoned equity issues irrational? Evidence from Spain
2007
Abstract We investigate if the long-run underperformance in the year after the issue of a sample of Spanish SEO firms is related to behavioural biases that lead investors to slowly adjust their pre-issue overoptimism. We also examine the existence of arbitrage costs that preclude mispricing from being corrected rapidly by sophisticated investors who act as arbitrageurs. Our findings support the contention that small SEO firms are overpriced at the time of the issue and suggest that their post-underperformance is related to arbitrage costs, where transaction costs play an important role although holding costs do not.
Algebraic (2, 2)-transformation groups
2009
This paper contains the more significant part of the article with the same title that will appear in the Volume 12 of Journal of Group Theory (2009). In this paper we determine all algebraic transformation groups $G$, defined over an algebraically closed field $\sf k$, which operate transitively, but not primitively, on a variety $\Omega$, provided the following conditions are fulfilled. We ask that the (non-effective) action of $G$ on the variety of blocks is sharply 2-transitive, as well as the action on a block $\Delta$ of the normalizer $G_\Delta$. Also we require sharp transitivity on pairs $(X,Y)$ of independent points of $\Omega$, i.e. points contained in different blocks.
Indexing Method for Transitive Relationships of Product Information
2008
To successfully use a relational database management system (RDBMS) as a repository for product information, the RDBMS must efficiently process and properly answer ontological queries. The key to processing the ontological queries is whether the various semantic relationships among the concepts of the product ontology are likewise well-processed. In particular, the transitive relationships (e.g., is-a, component-of relationships) such as ancestors-descendents, parents-children, and taxonomy of products must be processed successfully. We propose an efficient index using a numbering scheme (labeling scheme) to process queries over transitive relationships. (This paper is an extended version o…
Boundary-layer Flows Past an Hemispherical Roughness Element: DNS, Global Stability and Sensitivity Analysis
2015
Abstract We investigate the full three-dimensional instability mechanism arising in the wake of an hemispherical roughness element immersed in a laminar Blasius boundary layer. The inherent three-dimensional flow pattern beyond the critical Reynolds number is characterized by coherent vortical structures called hairpin vortices. Direct numerical simulation is used to analyze the formation and the shedding of hairpin packets inside the shear layer. The first bifurcation characteristics are investigated by global stability tools. We show the spatial structure of the linear direct and adjoint global eigenmodes of the linearized Navier-Stokes operator and use structural sensitivity analysis to …
A free plate model can predict guided modes propagating in tubular bone-mimicking phantoms
2014
The goal of this work was to show that a non-absorbing free plate model can predict with a reasonable accuracy guided modes measured in bone-mimicking phantoms that have circular cross-section. Experiments were carried out on uncoated and coated phantoms using a clinical axial transmission setup. Adjustment of the plate model to the experimental data yielded estimates for the waveguide characteristics (thickness, bulk wave velocities). Fair agreement was achieved over a frequency range of 0.4 to 1.6 MHz. A lower accuracy observed for the thinnest bone-mimicking phantoms was caused by limitations in the wave number measurements rather than by the model itself.
Extended Environmental Contour Methods for Long-Term Extreme Response Analysis of Offshore Wind Turbines1
2020
Abstract Environmental contour method is an efficient method for predicting the long-term extreme response of offshore structures. The traditional environmental contour is obtained using the joint distribution of mean wind speed, significant wave height, and spectral peak period. To improve the accuracy of traditional environmental contour method, a modified method was proposed considering the non-monotonic aerodynamic behavior of offshore wind turbines. Still, the modified method assumes constant wind turbulence intensity. In this paper, we extend the existing environmental contour methods by considering the wind turbulence intensity as a stochastic variable. The 50-year extreme responses …
A mathematical model of the self-averaging Pitot tube
2005
Abstract Flowmeters with self-averaging Pitot tubes are more and more often applied in practice. Their advantages are practically no additional flow losses, usability in the case of high temperature of fluids and simplicity of fitting. A mathematical model of a self-averaging Pitot tube including the influence of the probe shape, selected constructional features and flow conditions on the quantity of differential pressure gained has been given in this paper. The values and ranges of variations of the coefficients established for the model have been assessed on the basis of the numerically computed velocity and pressure fields around and inside the probe. Velocity and pressure fields were ca…
Tipología de los errores en el cálculo mental : un estudio en el contexto educativo
1995
Resumen basado en el de la publicación Resumen en inglés Se aborda una tipología de errores y dificultades de los estudiantes españoles de un Colegio de Formación de Profesores cuando aplican métodos históricos de cálculo mental (métodos tomados de la tradición escrita que se encuentra en la aritmética) de los libros de texto para resolver problemas con números naturales y con números decimales. ESP
Chiral Low-Energy Constants: Status and Prospects
2007
7 pages.-- PACS nrs.: 11.15.Pg, 12.38.-t, 12.39.Fe.-- ISI Article Identifier: 000252187200017.-- ArXiv pre-print available at: http://arxiv.org/abs/0710.4405