4,583 research outputs found
Probing the gluon density of the proton in the exclusive photoproduction of vector mesons at the LHC: A phenomenological analysis
The current uncertainty on the gluon density extracted from the global parton
analysis is large in the kinematical range of small values of the Bjorken -
variable and low values of the hard scale . An alternative to reduces this
uncertainty is the analysis of the exclusive vector meson photoproduction in
photon - hadron and hadron - hadron collisions. This process offers a unique
opportunity to constrain the gluon density of the proton, since its cross
section is proportional to the gluon density squared. In this paper we consider
current parametrizations for the gluon distribution and estimate the exclusive
vector meson photoproduction cross section at HERA and LHC using the leading
logarithmic formalism. We perform a fit of the normalization of the
cross section and the value of the hard scale for the process and demonstrate
that the current LHCb experimental data are better described by models that
assume a slow increasing of the gluon distribution at small - and low
.Comment: 8 pages, 6 figures, 1 table. Version published in European Physical
Journal
The Absence of Gender Differences Among Students in an MIS Program
The declining proportion of women in the IT profession contributes to the shortage of IT professionals and potentially has a detrimental effect on the success of design projects. However, we do not fully understand why that decrease is happening. Some studies have utilized a construct called stereotype threat to explain why women are rejecting IT as a profession. Others have claimed that the results of stereotype threat apply only in computer science programs housed in engineering schools. This study tests whether stereotype threat exists in an MIS program in a college of business and, if so, how it affects women’s confidence in their ability and motivation to continue their IT education. The results show no support for the stereotype threat hypothesis. Further analysis, however, shows that positive, supportive messages have more effect on these women than do the negative messages. Thus, while stereotype threat has been a successful model for explaining the behavior of women in the sciences, mathematics, and computer science, it does not appear to explain the decreases in the number of women in MIS programs in business schools. A discussion of the aspects of MIS programs that may attract women and possible ways to increase women are provided
Making Data Flow Diagrams Accessible for Visually Impaired Students Using Excel Tables
This paper addresses the use of Excel tables to convey information to blind students that would otherwise be presented using graphical tools, such as Data Flow Diagrams. These tables can supplement diagrams in the classroom when introducing their use to understand the scope of a system and its main sub-processes, on exams when answering questions about such relationships, or in group projects in discussing problems with and recommendations for systems. The main contributions are a)a suggestion on how to translate the different aspects of Data Flow Diagrams into a table format and b) the in-classexperiences from using the approach. The approach can be broadened to other graphical representations such as Entity-Relationship Diagrams or Use-Case Diagrams. Further, this approach could be broadened to support alternative learning styles of sighted students in the class
Information System Development Methodologies as Learning Systems
Although information system development methodologies supposedly improve development processes and end-products, information systems have continued to fail. In practice, methodologies have not been universally accepted, and even when accepted, not consistently used. Often development teams adapt methodologies to respond to perceived problems in past applications and/or specifics of the project under consideration. While it is possible that a combination of these factors contributed to less-than-effective system development processes or final end-products, we believe that there may be a subtler explanation for such failures. Although methodologies recommend best practices for system development, they rarely prescribe mechanisms to capture or evaluate problems encountered during system development. Specifically, methodologies do not include “learning” mechanisms that may be useful in improving the effectiveness of processes and end-products. We outline a meta-methodology for system development methodologies, which describes ways in which learning at different levels can be used to improve the effectiveness of system development methodologies
FEM for elliptic eigenvalue problems: how coarse can the coarsest mesh be chosen? An experimental study
In this paper, we consider the numerical discretization of elliptic eigenvalue problems by Finite Element Methods and its solution by a multigrid method. From the general theory of finite element and multigrid methods, it is well known that the asymptotic convergence rates become visible only if the mesh width h is sufficiently small, h≤h 0. We investigate the dependence of the maximal mesh width h 0 on various problem parameters such as the size of the eigenvalue and its isolation distance. In a recent paper (Sauter in Finite elements for elliptic eigenvalue problems in the preasymptotic regime. Technical Report. Math. Inst., Univ. Zürich, 2007), the dependence of h 0 on these and other parameters has been investigated theoretically. The main focus of this paper is to perform systematic experimental studies to validate the sharpness of the theoretical estimates and to get more insights in the convergence of the eigenfunctions and -values in the preasymptotic regim
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