4,905 research outputs found
A phenomenological interpretation of open charm production at HERA in terms of the semi-hard approach
In the framework of the semi-hard (k_t-factorization) approach, we analyze
the various charm production processes in the kinematic region covered by the
HERA experiments.Comment: DESY 02-017, LUNFD6/(NFFL--7209) 200
Pulsating strings in I-brane background
We study pulsating strings both on a single stack of NS5-branes and two
orthogonal stacks of NS5-branes (the so called I-brane) by using the Polyakov
form of the fundamental string action. For the I-brane background, by using a
symmetry that decouples the two spheres from the flat geometry, we study
pulsating solutions of the string when it pulsates on both the spheres
independently and simultaneously. We finally derive the energy of pulsating
strings as a function of adiabatic invariant oscillation number in these cases
and studied some limiting cases in detail.Comment: 24 pages, 6 figure
Neumann-Rosochatius system for strings on I-brane
We study rigidly rotating and pulsating strings in the background of a 1+1
dimensional intersection of two orthogonal stacks of fivebranes in type IIB
string theory by using the Neumann-Rosochatius (NR) model. Starting with the
Polyakov action of the probe fundamental string we show that a generalised
ansatz reduce the system into the one dimensional NR model in the presence of
flux. The integrable construction of the model is exploited to analyze the
rotating and oscillating string solution. We render the large BMN-type
expansion for the energy of rotating string states while the same for the
oscillating string has been derived in long string and small angular momenta
limit.Comment: 18 page
Minimal Energy Efficient Routing (MEER) Protocol using GSP For Sensor Network
The most important criterion while designing wireless sensor network is the consumption of energy[5,6,7]. There are many schemes cited for conservation of energy issues[1,2,8]. Again the efficient minimal energy consumption routing schemes are an important consideration. In this paper, we have proposed an energy saving scheme, named as minimal energy efficient routing (MEER) Protocol, which uses GSP (Gossip based sleep Protocol) to achieve energy efficiency in sensor networks. Here, we have compared our work with the existing work given by GSP[1] . We have shown the correctness & effectiveness of our protocol by mathematical simulation studies
A Review Of Trends In Research On Web Mining
In recent years the growth of the World Wide Web exceeded all expectations. Today there are several billions of HTML documents, pictures and other multimedia files available via internet and the number is still rising. But considering the impressive variety of the web, retrieving interesting content has become a very difficult task.So, the World Wide Web is a fertile area for data mining research.Web mining is a research topic which combines two of the activated research areas: Data Mining and World Wide Web. Web mining research relates to several research communities such as Database, information Retrieval and Artificial intelligence, visualization.This paper reviews the research and application issues in web mining besides proving an overall view of Web mining
Web Usage Mining: A Survey on Pattern Extraction from Web Logs
As the size of web increases along with number of users, it is very much essential for the website owners to better understand their customers so that they can provide better service, and also enhance the quality of the website. To achieve this they depend on the web access log files. The web access log files can be mined to extract interesting pattern so that the user behaviour can be understood. This paper presents an overview of web usage mining and also provides a survey of the pattern extraction algorithms used for web usage mining
Invariant Synthesis for Incomplete Verification Engines
We propose a framework for synthesizing inductive invariants for incomplete
verification engines, which soundly reduce logical problems in undecidable
theories to decidable theories. Our framework is based on the counter-example
guided inductive synthesis principle (CEGIS) and allows verification engines to
communicate non-provability information to guide invariant synthesis. We show
precisely how the verification engine can compute such non-provability
information and how to build effective learning algorithms when invariants are
expressed as Boolean combinations of a fixed set of predicates. Moreover, we
evaluate our framework in two verification settings, one in which verification
engines need to handle quantified formulas and one in which verification
engines have to reason about heap properties expressed in an expressive but
undecidable separation logic. Our experiments show that our invariant synthesis
framework based on non-provability information can both effectively synthesize
inductive invariants and adequately strengthen contracts across a large suite
of programs
Size-dependent spinodal and miscibility gaps for intercalation in nano-particles
Using a recently-proposed mathematical model for intercalation dynamics in
phase-separating materials [Singh, Ceder, Bazant, Electrochimica Acta 53, 7599
(2008)], we show that the spinodal and miscibility gaps generally shrink as the
host particle size decreases to the nano-scale. Our work is motivated by recent
experiments on the high-rate Li-ion battery material LiFePO4; this serves as
the basis for our examples, but our analysis and conclusions apply to any
intercalation material. We describe two general mechanisms for the suppression
of phase separation in nano-particles: (i) a classical bulk effect, predicted
by the Cahn-Hilliard equation, in which the diffuse phase boundary becomes
confined by the particle geometry; and (ii) a novel surface effect, predicted
by chemical-potential-dependent reaction kinetics, in which
insertion/extraction reactions stabilize composition gradients near surfaces in
equilibrium with the local environment. Composition-dependent surface energy
and (especially) elastic strain can contribute to these effects but are not
required to predict decreased spinodal and miscibility gaps at the nano-scale
A quadratic boundary element implementation in orthotropic elasticity using the real variable approach
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