4,753 research outputs found
Gravitational Decoupled Charged Anisotropic Spherical Solutions
The purpose of this paper is to obtain exact solutions for charged
anisotropic spherically symmetric matter configuration. For this purpose, we
consider known solution for isotropic spherical system in the presence of
electromagnetic field and extend it to two types of anisotropic charged
solutions through gravitational decoupling approach. We examine physical
characteristics of the resulting models. It is found that only first solution
is physically acceptable as it meets all the energy bounds as well as stability
criterion. We conclude that stability of the first model is enhanced with the
increase of charge.Comment: 20 pages, 6 figure
Cross cultural perspectives of decision-making and control in multinational corporations operating in ASEAN
Kajian ini membincangkan isu-isu persekitaran budaya negara ASEAN dan cabaran-cabarannya terhadap pengurus-pengurus korporat multi-nasional. Kajian ini melaporkan penemuan terhadap corak membuat keputusan, kawalan dan pengurusan budaya serta aspek gelagat. Walaupun penemuan ini mempunyai persamaan dengan kajian lain, namun terdapat perbezaan dalam corak membuat keputusan, kawalan dan pengurusan budaya serta aspek gelagat
Edge Detection: A Collection of Pixel based Approach for Colored Images
The existing traditional edge detection algorithms process a single pixel on
an image at a time, thereby calculating a value which shows the edge magnitude
of the pixel and the edge orientation. Most of these existing algorithms
convert the coloured images into gray scale before detection of edges. However,
this process leads to inaccurate precision of recognized edges, thus producing
false and broken edges in the image. This paper presents a profile modelling
scheme for collection of pixels based on the step and ramp edges, with a view
to reducing the false and broken edges present in the image. The collection of
pixel scheme generated is used with the Vector Order Statistics to reduce the
imprecision of recognized edges when converting from coloured to gray scale
images. The Pratt Figure of Merit (PFOM) is used as a quantitative comparison
between the existing traditional edge detection algorithm and the developed
algorithm as a means of validation. The PFOM value obtained for the developed
algorithm is 0.8480, which showed an improvement over the existing traditional
edge detection algorithms.Comment: 5 Page
Bounds on R-parity violating SUSY Yukawa couplings from semileptonic decays of baryons
We consider tree-level corrections to hypercharge changing semileptonic
decays of certain baryons induced by a minimal supersymmetric standard model
with explicitly broken R-parity via -violation. This study leads to a new
set of constraints on the products of couplings arising from the LQd
operator of the superpotential.Comment: Latex (8 pages), no figur
Effects of ozone-vegetation coupling on surface ozone air quality via biogeochemical and meteorological feedbacks
Tropospheric ozone is one of the most hazardous air pollutants as it harms both human health and plant productivity. Foliage uptake of ozone via dry deposition damages photosynthesis and causes stomatal closure. These foliage changes could lead to a cascade of biogeochemical and biogeophysical effects that not only modulate the carbon cycle, regional hydrometeorology and climate, but also cause feedbacks onto surface ozone concentration itself. In this study, we implement a semi-empirical parameterization of ozone damage on vegetation in the Community Earth System Model to enable online ozone-vegetation coupling, so that for the first time ecosystem structure and ozone concentration can coevolve in fully coupled land-Atmosphere simulations. With ozone-vegetation coupling, present-day surface ozone is simulated to be higher by up to 4-6ĝ€ppbv over Europe, North America and China. Reduced dry deposition velocity following ozone damage contributes to ĝ1/4 40-100ĝ€% of those increases, constituting a significant positive biogeochemical feedback on ozone air quality. Enhanced biogenic isoprene emission is found to contribute to most of the remaining increases, and is driven mainly by higher vegetation temperature that results from lower transpiration rate. This isoprene-driven pathway represents an indirect, positive meteorological feedback. The reduction in both dry deposition and transpiration is mostly associated with reduced stomatal conductance following ozone damage, whereas the modification of photosynthesis and further changes in ecosystem productivity are found to play a smaller role in contributing to the ozone-vegetation feedbacks. Our results highlight the need to consider two-way ozone-vegetation coupling in Earth system models to derive a more complete understanding and yield more reliable future predictions of ozone air quality
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