148,712 research outputs found
A model for querying semistructured data through the exploitation of regular sub-structures
Much research has been undertaken in order to speed up the processing of semistructured data in general and XML in particular. Many approaches for storage, compression, indexing and querying exist, e.g. [1, 2]. We do not present yet another such algorithm but a unifying model in which these algorithm can be understood. The key idea behind this research is the assumption, that most practical queries are based on a particular pattern of data that can be deduced from the query and which can then be captured using a regular structure amendable to efficient processing techniques
Decay channels and charmonium mass-shifts
The discovery in the last few years of the and states of the
extended charmonium family has highlighted the importance of the closeness of
decay channels to an understanding of these mesons. We aid this debate by
illustrating a simple calculational procedure for including the effect of open
and nearby closed channels.Comment: 4 pages, 2 figures Revised version: (1) corrected 2 typos in Table
II, (2) additional text in penultimate paragraph to clarify the calculation
of mass-shifts for and . We thank colleagues for pointing
out confusing wording of previous tex
Recommended from our members
Developments in linear and integer programming
In this review we describe recent developments in linear and integer (linear) programming. For over 50 years Operational Research practitioners have made use of linear optimisation models to aid decision making and over this period the size of problems that can be solved has increased dramatically, the time required to solve problems has decreased substantially and the flexibility of modelling and solving systems has increased steadily. Large models are no longer confined to large computers, and the flexibility of optimisation systems embedded in other decision support tools has made on-line decision making using linear programming a reality (and using integer programming a possibility). The review focuses on recent developments in algorithms, software and applications and investigates some connections between linear optimisation and other technologies
Novel superconductivity: from bulk to nano systems
We begin with an introduction of superconductivity by giving a brief history of the phenomenon. The phenomenological Ginzburg–Landau theory and the microscopic theory of Bardeen, Cooper and Schrieffer are outlined. In view of recently available multi-band superconductors, relevant theories of both types are discussed. Unlike the traditional GL theory an extended GL theory is developed relevant to temperatures below the critical temperature. Superconductivity in a nanosystem is the highlight of the remaining part of the paper. Theories and experiments are discussed to give an interested reader an updated account and overview of what is new in this active area of research
4He adsorbed inside (10,10) single walled carbon nanotubes
Diffusion Monte Carlo calculations on the adsorption of He in open-ended
single walled (10,10) nanotubes are presented. We have found a first order
phase transition separating a low density liquid phase in which all He
atoms are adsorbed close to the tube wall and a high density arrangement
characterized by two helium concentric layers. The energy correction due to the
presence of neighboring tubes in a bundle has also been calculated, finding it
negligible in the density range considered.Comment: 5 pages, accepted for publication in Phys. Rev.
Studies of the nucler equation of state using numerical calculations of nuclear drop collisions
A numerical calculation for the full thermal dynamics of colliding nuclei was developed. Preliminary results are reported for the thermal fluid dynamics in such processes as Coulomb scattering, fusion, fusion-fission, bulk oscillations, compression with heating, and collisions of heated nuclei
Organic slug control using Phasmarhabditis hermaphrodita
Phasmarhabditis hermaphrodita is a lethal slug parasitic nematode that has been formulated into an effective biological control agent called Nemaslug®. We investigated the possibility of using different application methods of P. hermaphrodita to reduce cost and the number of nematodes applied. We also compared P. hermaphrodita with a new slug pellet called Ferramol®, which is available for use on organic farms
- …