13,852 research outputs found
Vitu grammar sketch
PL 6257.3, ISO 639-3 : wiv, Muduapa language--GrammarAbbreviations Maps 1. Introduction 2. Phonology 3. Nouns and noun phrases 4. Verbs 5. Aspect-mood-sequentiality 6. The prepositional phrase 7. The clause 8. Clausal modifications 9. Complex sentences Appendix: two texts Text 1. Varivuvuka haroho (‘The beginning of fire’) Text 2: Dudu kamani Bilimariva (‘Dudu and Bilimariva’) Bibliograph
Out of Equilibrium Solutions in the -Hamiltonian Mean Field model
Out of equilibrium magnetised solutions of the -Hamiltonian Mean Field
(-HMF) model are build using an ensemble of integrable uncoupled pendula.
Using these solutions we display an out-of equilibrium phase transition using a
specific reduced set of the magnetised solutions
Gravitational diffraction radiation
We show that if the visible universe is a membrane embedded in a
higher-dimensional space, particles in uniform motion radiate gravitational
waves because of spacetime lumpiness. This phenomenon is analogous to the
electromagnetic diffraction radiation of a charge moving near to a metallic
grating. In the gravitational case, the role of the metallic grating is played
by the inhomogeneities of the extra-dimensional space, such as a hidden brane.
We derive a general formula for gravitational diffraction radiation and apply
it to a higher-dimensional scenario with flat compact extra dimensions.
Gravitational diffraction radiation may carry away a significant portion of the
particle's initial energy. This allows to set stringent limits on the scale of
brane perturbations. Physical effects of gravitational diffraction radiation
are briefly discussed.Comment: 5 pages, 2 figures, RevTeX4. v2: References added. Version to appear
in Phys. Rev.
Performance analysis of wireless LANs: an integrated packet/flow level approach
In this paper we present an integrated packet/flow level modelling approach for analysing flow throughputs and transfer times in IEEE 802.11 WLANs. The packet level model captures the statistical characteristics of the transmission of individual packets at the MAC layer, while the flow level model takes into account the system dynamics due to the initiation and completion of data flow transfers. The latter model is a processor sharing type of queueing model reflecting the IEEE 802.11 MAC design principle of distributing the transmission capacity fairly among the active flows. The resulting integrated packet/flow level model is analytically tractable and yields a simple approximation for the throughput and flow transfer time. Extensive simulations show that the approximation is very accurate for a wide range of parameter settings. In addition, the simulation study confirms the attractive property following from our approximation that the expected flow transfer delay is insensitive to the flow size distribution (apart from its mean)
Heat trace asymptotics with singular weight functions
We study the weighted heat trace asymptotics of an operator of Laplace type
with Dirichlet boundary conditions where the weight function exhibits radial
blowup. We give formulas for the first few terms in the expansion in terms of
geometrical data
Confinement of knotted polymers in a slit
We investigate the effect of knot type on the properties of a ring polymer
confined to a slit. For relatively wide slits, the more complex the knot, the
more the force exerted by the polymer on the walls is decreased compared to an
unknotted polymer of the same length. For more narrow slits the opposite is
true. The crossover between these two regimes is, to first order, at smaller
slit width for more complex knots. However, knot topology can affect these
trends in subtle ways. Besides the force exerted by the polymers, we also study
other quantities such as the monomer-density distribution across the slit and
the anisotropic radius of gyration.Comment: 9 pages, 6 figures, submitted for publicatio
Allergic sensitisation in South Africa: Exploring regional variation in sensitisation
Background. Allergy is a common health problem in South Africa (SA), and a rational approach to allergy testing is essential to ensure cost-effective as well as optimal patient diagnosis and management.Objectives. To review allergy testing data with respect to current national testing recommendations, and to explore the regional variations in sensitisation.Methods. Retrospective data review on allergy testing from a private pathology provider in SA over a 2-year period. Data on skin-prick testing (SPT) and allergen-specific IgE testing originating from all the provinces of SA were collected and analysed with regards to allergen positivity rate and regional sensitisation patterns.Results. Among the patients (N=45 0320) tested for a suspected inhalant allergy, 46% tested positive. Only 45% of these received additional testing for the nine recommended inhalant allergens included in the current national testing protocol. Among the patients (N=6 775) who received SPT for a suspected inhalant allergy, 59% yielded one or more positive results. The most frequent sensitising allergens were house dust mite (Dermatophagoides pteronyssinus) and grass pollen. The house dust mite, Blomia tropicalis, was a significant sensitiser in coastal regions. SPT identified two other important regional allergens which are not included in the current recommendations for inhalant allergen-specific IgE testing.Conclusions. The current diagnostic recommendations include allergens that demonstrate significant sensitisation in all regions of SA. Two additional allergens that show significant regional sensitisation in the South African population were identified. These findings may aid the recommendations for the most appropriate and cost-effective approach to allergy testing of symptomatic patients in SA
- …