3,726,632 research outputs found
CUFTS: An Open Source Alternative for Serials Management
For libraries searching for an affordable way to manage their growing online serials collections, CUFTS open source serials management software provides an effective alternative to more traditional commercial solutions
An Alternative Source for Dark Energy
In the present work, an alternative interpretation of the source of
accelerated expansion of the Universe is suggested. A probable candidate is the
interaction between the quantum spin of a moving particle and the torsion of
space-time, produced by the background gravitational field of the Universe.
This interaction has been suggested by the author in a previous work, with some
experimental and observational evidences for its existence. It has been shown
that this interaction gives rise to a repulsive force. The accelerated
expansion of the Universe may give a further evidence on the existence of this
interaction on the cosmological scale.Comment: 3 pages, LaTeX file, summary of a talk delivered at MG XI, held in
Berlin, July 200
Microbial fuel cells: a green and alternative source for bioenergy production
Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)
Long-lived plasma formations in the atmosphere as an alternative energy source
A model of a stable plasma formation, based on radial quantum oscillations of
charged particles, is discussed. The given plasmoid is described with the help
of the nonlinear Schr\"odinger equation. A new phenomenon of the effective
attraction between oscillating charged particles is considered within the
framework of the proposed model. The possible existence of a composite plasma
structure is also discussed. Hypothesis about using the obtained results to
describe natural long-lived plasma formations, which can serve as alternative
energy sources, is put forward.Comment: 6 pages in pdf; mini review to be published in Russian Physics
Journa
First- and Second-Order Hypothesis Testing for Mixed Memoryless Sources with General Mixture
The first- and second-order optimum achievable exponents in the simple
hypothesis testing problem are investigated. The optimum achievable exponent
for type II error probability, under the constraint that the type I error
probability is allowed asymptotically up to epsilon, is called the
epsilon-optimum exponent. In this paper, we first give the second-order
epsilon-exponent in the case where the null hypothesis and the alternative
hypothesis are a mixed memoryless source and a stationary memoryless source,
respectively. We next generalize this setting to the case where the alternative
hypothesis is also a mixed memoryless source. We address the first-order
epsilon-optimum exponent in this setting. In addition, an extension of our
results to more general setting such as the hypothesis testing with mixed
general source and the relationship with the general compound hypothesis
testing problem are also discussed.Comment: 23 page
Automated detection of extended sources in radio maps: progress from the SCORPIO survey
Automated source extraction and parameterization represents a crucial
challenge for the next-generation radio interferometer surveys, such as those
performed with the Square Kilometre Array (SKA) and its precursors. In this
paper we present a new algorithm, dubbed CAESAR (Compact And Extended Source
Automated Recognition), to detect and parametrize extended sources in radio
interferometric maps. It is based on a pre-filtering stage, allowing image
denoising, compact source suppression and enhancement of diffuse emission,
followed by an adaptive superpixel clustering stage for final source
segmentation. A parameterization stage provides source flux information and a
wide range of morphology estimators for post-processing analysis. We developed
CAESAR in a modular software library, including also different methods for
local background estimation and image filtering, along with alternative
algorithms for both compact and diffuse source extraction. The method was
applied to real radio continuum data collected at the Australian Telescope
Compact Array (ATCA) within the SCORPIO project, a pathfinder of the ASKAP-EMU
survey. The source reconstruction capabilities were studied over different test
fields in the presence of compact sources, imaging artefacts and diffuse
emission from the Galactic plane and compared with existing algorithms. When
compared to a human-driven analysis, the designed algorithm was found capable
of detecting known target sources and regions of diffuse emission,
outperforming alternative approaches over the considered fields.Comment: 15 pages, 9 figure
A Note on the Shannon Entropy of Short Sequences
For source sequences of length L symbols we proposed to use a more realistic
value to the usual benchmark of number of code letters by source letters. Our
idea is based on a quantifier of information fluctuation of a source, F(U),
which corresponds to the second central moment of the random variable that
measures the information content of a source symbol. An alternative
interpretation of typical sequences is additionally provided through this
approach.Comment: 3 figure
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