6,235 research outputs found
Stability for an inverse problem for a two speed hyperbolic pde in one space dimension
We prove stability for a coefficient determination problem for a two velocity
2x2 system of hyperbolic PDEs in one space dimension.Comment: Revised Version. Give more detail and correct the proof of
Proposition 4 regarding the existence and regularity of the forward problem.
No changes to the proof of the stability of the inverse problem. To appear in
Inverse Problem
Self-organising management of Grid environments
This paper presents basic concepts, architectural principles and algorithms for efficient resource and security management in cluster computing environments and the Grid. The work presented in this paper is funded by BTExacT and the EPSRC project SO-GRM (GR/S21939)
Recommended from our members
Integrating RC bridge defect information into BIM models
Reinforced Concrete bridges are a vitally important part of our infrastructure. The status of this infrastructure needs to be monitored on a continuous basis in order to ensure its safety and functionality. This is currently being done by authorities worldwide via bridge inspection reports. The format and storage of these reports varies considerably across different authorities around the world and is sometimes comprised into a bridge management system (BMS). The lack of standardization severely hinders the use of inspection information for knowledge generation use cases of both practitioners and researchers. This paper presents an exploratory analysis and as a result an information model and a candidate binding to IFC to categorize inspection information of RC bridges and to standardize storage of this information in a format that is suitable for sharing and comparing it between different users and varying requirements. We were able to show in three steps, that IFC in its latest version IFC 4 provides sufficient functionality to serve as a basis for integrating relevant defect information and imagery. Firstly, we extracted types of defects and properties needed for bridge assessment from existing bridge inspection manuals. Secondly, we modelled the defect entities, their properties and relations and thirdly, mapped them to appropriate IFC entities. A prototypical implementation serves as a proof of concept for automated sharing and comparing of information needed in RC bridge inspections and for establishing a knowledge base for bridge performance over time and across authorities.This work is partly funded by Trimble Inc. and by the European Unionâs Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 31109806.0007. SeeBridge is co-funded by Funding Partners of the ERA-NET Plus Infravation and the European Commission. The Funding Partners of the Infravation 2014 Call are: Ministerie van Infrastructuur en Milieu, Rijkswaterstaat, Bundesministerium fĂŒr Verkehr, Bau und Stadtentwicklung, Danish Road Directorate, Statens Vegvesen Vegdirektoratet, Trafikverket â Trv, VegagerĂ°in, Ministere de Lâecologie, du Developpement Durable et de Lâenergie, Centro para el Desarrollo Tecnologico Industrial, Anas S.P.A., Netivei Israel â National Transport Infrastructure Company Ltd. and Federal Highway Administration USDOT
Probing the superfluid velocity with a superconducting tip: the Doppler shift effect
We address the question of probing the supercurrents in superconducting (SC)
samples on a local scale by performing Scanning Tunneling Spectroscopy (STS)
experiments with a SC tip. In this configuration, we show that the tunneling
conductance is highly sensitive to the Doppler shift term in the SC
quasiparticle spectrum of the sample, thus allowing the local study of the
superfluid velocity. Intrinsic screening currents, such as those surrounding
the vortex cores in a type II SC in a magnetic field, are directly probed. With
Nb tips, the STS mapping of the vortices, in single crystal 2H-NbSe_2, reveals
both the vortex cores, on the scale of the SC coherence length , and the
supercurrents, on the scale of the London penetration length . A
subtle interplay between the SC pair potential and the supercurrents at the
vortex edge is observed. Our results open interesting prospects for the study
of screening currents in any superconductor.Comment: 4 pages, 5 figure
Scanning Tunneling Spectroscopy on the novel superconductor CaC6
We present scanning tunneling microscopy and spectroscopy of the newly
discovered superconductor CaC. The tunneling conductance spectra, measured
between 3 K and 15 K, show a clear superconducting gap in the quasiparticle
density of states. The gap function extracted from the spectra is in good
agreement with the conventional BCS theory with = 1.6 0.2
meV. The possibility of gap anisotropy and two-gap superconductivity is also
discussed. In a magnetic field, direct imaging of the vortices allows to deduce
a coherence length in the ab plane 33 nm
Nanometer Scale Mapping of the Density of States in an Inhomogeneous Superconductor
Using high speed scanning tunneling spectroscopy, we perform a full mapping
of the quasiparticle density of states (DOS) in single crystals of
BiPbSrCaCuO(2212). The measurements carried out at 5 K showed a complex spatial
pattern of important variations of the local DOS on the nanometer scale.
Superconducting areas are co-existing with regions of a smooth and larger
gap-like DOS structure. The superconducting regions are found to have a minimum
size of about 3 nm. The role of Pb-introduced substitutional disorder in the
observed spatial variations of the local DOS is discussed.Comment: 4 page Letter with 3 figures (2 color figures
New insights into the effects on blood pressure of diets low in salt and high in fruits and vegetables and low-fat dairy products
Results from the recent Dietary Approaches to Stop Hypertension (DASH)-Sodium trial provide the latest evidence concerning the effects of dietary patterns and sodium intake on blood pressure. Participants ate either the DASH diet (high in fruits, vegetables and low-fat dairy products, and reduced in saturated and total fat) or a typical US diet. Within each diet arm, participants ate higher, intermediate, and lower sodium levels, each for 30 days. The results indicated lower blood pressure with lower sodium intake for both diet groups. Although some critics would argue otherwise, these findings provide important new evidence for the value of the DASH diet and sodium reduction in controlling blood pressure
Auto-immune haematological complications occurring during the treatment of malignant lymphoproliferative diseases
Auto-immune haematological complications occurring during treatment for malignant Iymphoproliferative diseases are described in 5 patients. There appeared to be a temporal relationship between the development of these complications and the administration of chemotherapeutic drugs or extensive radiotherapy.S. Afr. Med. J., 48, 2143 (1974)
- âŠ