1,972 research outputs found
Metadata-Based Integration of Qualitative and Quantitative Information Resources Approaching Knowledge Management
This paper presents a concept for the integration of quantitative and qualitative information sources with their accompanying management support functionalities from navigation and retrieval up to analysis and business intelligence. The integration is realized by a common keyword-based metadata base, retrievable and extendible by the end user on a web-based platform. This enables a dynamic acquisition of supplementary information on the usage, usability and benefit of basic and derived information objects, e.g. data warehouses, data marts, OLAP cubes, reports or (textual) documents. Being extended by functions to automatically catch contextual links during system usage, the concept is discussed as a contribution to the implementation of knowledge management. The concept is being developed and successfully tested in the practical environment of a reference project for the implementation of an IT-infrastructure to support decentralized decision-making at a German university
Bilinear identities on Schur symmetric functions
A series of bilinear identities on the Schur symmetric functions is obtained
with the use of Pluecker relations.Comment: Accepted to Journal of Nonlinear Mathematical Physics. A reference to
a connected result is adde
Regular and quasi black hole solutions for spherically symmetric charged dust distributions in the Einstein-Maxwell theory
Static spherically symmetric distributions of electrically counterpoised dust
(ECD) are used to construct solutions to Einstein-Maxwell equations in
Majumdar--Papapetrou formalism. Unexpected bifurcating behaviour of solutions
with regard to source strength is found for localized, as well as for the
delta-function ECD distributions. Unified treatment of general ECD
distributions is accomplished and it is shown that for certain source strengths
one class of regular solutions approaches Minkowski spacetime, while the other
comes arbitrarily close to black hole solutions.Comment: LaTeX (IOP style) 17 pages, 10 figure
Quasiblack holes with pressure: relativistic charged spheres as the frozen stars
In general relativity coupled to Maxwell's electromagnetism and charged
matter, when the gravitational potential and the electric potential field
obey a relation of the form , where , and are arbitrary constants, and (the
speed of light and Newton's constant are put to one), a class of very
interesting electrically charged systems with pressure arises. We call the
relation above between and , the Weyl-Guilfoyle relation, and it
generalizes the usual Weyl relation, for which . For both, Weyl and
Weyl-Guilfoyle relations, the electrically charged fluid, if present, may have
nonzero pressure. Fluids obeying the Weyl-Guilfoyle relation are called
Weyl-Guilfoyle fluids. These fluids, under the assumption of spherical
symmetry, exhibit solutions which can be matched to the electrovacuum
Reissner-Nordstr\"om spacetime to yield global asymptotically flat cold charged
stars. We show that a particular spherically symmetric class of stars found by
Guilfoyle has a well-behaved limit which corresponds to an extremal
Reissner-Nordstr\"om quasiblack hole with pressure, i.e., in which the fluid
inside the quasihorizon has electric charge and pressure, and the geometry
outside the quasihorizon is given by the extremal Reissner-Nordstr\"om metric.
The main physical properties of such charged stars and quasiblack holes with
pressure are analyzed. An important development provided by these stars and
quasiblack holes is that without pressure the solutions, Majumdar-Papapetrou
solutions, are unstable to kinetic perturbations. Solutions with pressure may
avoid this instability. If stable, these cold quasiblack holes with pressure,
i.e., these compact relativistic charged spheres, are really frozen stars.Comment: 16 pages, 8 figures; minor change
CARBON BALANCE AND VEGETATION DYNAMICS IN AN OLDâGROWTH AMAZONIAN FOREST
Amazon forests could be globally significant sinks or sources for atmospheric carbon dioxide, but carbon balance of these forests remains poorly quantified. We surveyed 19.75 ha along four 1âkm transects of wellâdrained oldâgrowth upland forest in the TapajĂłs National Forest near SantarĂ©m, ParĂĄ, Brazil (2°51âČ S, 54°58âČ W) in order to assess carbon pool sizes, fluxes, and climatic controls on carbon balance. In 1999 there were, on average, 470 live trees per hectare with diameter at breast height (dbh) â„10 cm. The mean (and 95% ci) aboveground live biomass was 143.7 ± 5.4 Mg C/ha, with an additional 48.0 ± 5.2 Mg C/ha of coarse woody debris (CWD). The increase of live wood biomass after two years was 1.40 ± 0.62 Mg C·haâ1·yrâ1, the net result of growth (3.18 ± 0.20 Mg C·haâ1·yrâ1 from mean bole increment of 0.36 cm/yr), recruitment of new trees (0.63 ± 0.09 Mg C·haâ1·yrâ1, reflecting a notably high stem recruitment rate of 4.8 ± 0.9%), and mortality (â2.41 ± 0.53 Mg C·haâ1·yrâ1 from stem death of 1.7% yrâ1). The gain in live wood biomass was exceeded by respiration losses from CWD, resulting in an overall estimated net loss from total aboveground biomass of 1.9 ± 1.0 Mg C·haâ1·yrâ1. The presence of large CWD pools, high recruitment rate, and net accumulation of smallâtree biomass, suggest that a period of high mortality preceded the initiation of this study, possibly triggered by the strong El Niño Southern Oscillation events of the 1990s. Transfer of carbon between live and dead biomass pools appears to have led to substantial increases in the pool of CWD, causing the observed net carbon release. The data show that biometric studies of tropical forests neglecting CWD are unlikely to accurately determine carbon balance. Furthermore, the hypothesized sequestration flux from CO2 fertilization (\u3c0.5 Mg C·haâ1·yrâ1) would be comparatively small and masked for considerable periods by climateâdriven shifts in forest structure and associated carbon balance in tropical forests
Customer service orientation on adhesion contracts
Hiring a service is a moment of great importance once it builds the perception of the service value and quality. Some companies may deal with that, assuming a greater importance when elaborating their service contracts. Usually law professional people elaborate these documents, but this may include legal attributes, not considering the service to the customers, as well as the customersâ point of view. In times of increasing on customer focus, market and service orientation, a question can be posted: to what extent company contracts show service or customer orientation? This paper compares the service orientation degree for Cable TV contracts from five companies, based on a theoretical model developed to this purpose. From a conceptual model for servant contract, four dimensions were assessed: physical aspects, reasonableness, intelligibility and customer focus. After subject evaluation by eight judges, analyzing the validation index (CVI), it was found that the contracts show moderate orientation to serve. Furthermore, results show that the five surveyed companyâs contracts showed a similar overall performance, i.e., none stood out over the other. The study presents important practical efficacy, because it can guide the Cable TV companies to adopt improvement strategies in elaboration of contracts, so that the contractual instruments be would reviewed of clauses that promote the sensation of better service to their customer. Thus, this article directs the manager to the aspect that deserves more attention, i.e, which dimensions require further refinement and direction to serv
Use of Physical Education Classes as a Didactic Laboratory for Teaching Mathematics: An Example with a Quadratic Function
The research objective of this study was to evaluate the use of Physical Education classes as didactic laboratory for lessons in Mathematics, presenting an alternative way to conduct classes, mainly of quadratic functions, illustrating basic concepts such as graphs plotting and determination coefficients, analyze if such use achieves some of the goals of using a Didactic Laboratory in addition to research ways to interdisciplinary with Physics. Discusses an action in which students work in groups to solve problems proposed based on empirical data obtained through play activities and measures of athletics values practiced by the students allowing may have the opportunity to produce arguments and more meaningful answers, which would improve the overall learning. The athletics and recreational activities are then used as problematic objects both empirically and qualitatively. As a result, it was observed that some of the objectives of a Didactic Laboratory are achieved when using the Physical Education classes and it appears that this feature is much more available in public schools than they are equipped with a science laboratory
Is legal status impacting outcomes of group therapy for posttraumatic stress disorder with male asylum seekers and refugees from Iran and Afghanistan?
Background: Legal status and other resettlement stressors are known to impact mental health of asylum seekers and refugees. However, the ways in which they interact with treatment of posttraumatic stress disorder (PTSD) with these populations is still poorly understood. The aim of this study was to examine whether legal status and other resettlement stressors influence outcomes of a trauma-focused group PTSD treatment within a day-treatment setting with asylum seekers and refugees.
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