6,211 research outputs found
Data Management and Mining in Astrophysical Databases
We analyse the issues involved in the management and mining of astrophysical
data. The traditional approach to data management in the astrophysical field is
not able to keep up with the increasing size of the data gathered by modern
detectors. An essential role in the astrophysical research will be assumed by
automatic tools for information extraction from large datasets, i.e. data
mining techniques, such as clustering and classification algorithms. This asks
for an approach to data management based on data warehousing, emphasizing the
efficiency and simplicity of data access; efficiency is obtained using
multidimensional access methods and simplicity is achieved by properly handling
metadata. Clustering and classification techniques, on large datasets, pose
additional requirements: computational and memory scalability with respect to
the data size, interpretability and objectivity of clustering or classification
results. In this study we address some possible solutions.Comment: 10 pages, Late
Super-Pop Culture: With Great Power, a Greater Irresponsibility
Analysis of superhero mythology in American comic books and of its ideological contradictions, especially as regards the issue of social responsibility
Fin loads and control-surface hinge moments measured in full-scale wind-tunnel tests on the X-24A flight vehicle
Fin loads and control surface hinge moments measured in full scale wind tunnel tests on X-24A flight vehicl
CHC-COMP 2022: Competition Report
CHC-COMP 2022 is the fifth edition of the competition of solvers for
Constrained Horn Clauses. The competition was run in March 2022; the results
were presented at the 9th Workshop on Horn Clauses for Verification and
Synthesis held in Munich, Germany, on April 3, 2022. This edition featured six
solvers, and eight tracks consisting of sets of linear and nonlinear clauses
with constraints over linear integer arithmetic, linear real arithmetic,
arrays, and algebraic data types. This report provides an overview of the
organization behind the competition runs: it includes the technical details of
the competition setup as well as presenting the results of the 2022 edition.Comment: In Proceedings HCVS/VPT 2022, arXiv:2211.10675. arXiv admin note:
text overlap with arXiv:2109.04635, arXiv:2008.02939 by other author
Hidden-variable theory versus Copenhagen quantum mechanics
The main assumptions the Copenhagen quantum mechanics has been based on will
be summarized and the known (not yet decided) contradiction between Einstein
and Bohr will be newly analyzed. The given assumptions have been represented
basically by time-dependent Schroedinger equation, to which some further
assumptions have been added. Some critical comments have been raised against
the given mathematical model structure by Pauli (1933) and by Susskind and
Glogover (1964). They may be removed if only the Schroedinger equation is
conserved and the additional assumptions are abandoned, as shown recently. It
seems to be in contradiction to the numerous declarations that the Copenhagen
model has been approved by experimental results.
However, in the most of these experiments only the agreement with the mere
Schroedinger equation has been tested. All mentioned assumptions have been
tested practically only in the EPR experiment (measurement of coincidence light
transmission through two polarizers) proposed originally by Einstein (1935).
Also these experimental results have been interpreted as supporting the
Copenhagen alternative, which has not been, however, true. In fact the
microscopic world may be described correspondingly only with the help of the
hidden-variable theory that is represented by the Schroedinger equation without
mentioned additional assumptions, which has the consequence that the earlier
interpretation gap between microscopic and macroscopic worlds has been removed.
The only difference concerns the existence of discrete states. The
possibilities of the human reason of getting to know the nature will be also
shortly discussed in the beginning of this contribution.Comment: 10 pages, 2 figures; v2: local refinements and improvements of the
tex
Ge-Doped microstructured multicorefiber for customizable supercontinuum generation
Supercontinuum generation in a multicore fiber in which several uncoupled cores
were doped with dissimilar concentrations of germanium was studied experimentally.
Germanium doping provided control over the separation between the zero-dispersion
wavelength and the 1064-nm wavelength of a Q-switched Nd:YAG pump laser. Supercontinua
generated independently in each core of the same piece of fiber displayed clear
and repeatable differences due to the influence of germanium doping on refractive index and
four-wave mixing. The spectral evolution of the subnanosecond pump pulses injected into
the different cores was accurately reproduced by numerical simulations
Large-scale albuminuria screen for nephropathy models in chemically induced mouse mutants
Background/Aim: Phenotype-driven screening of a great pool of randomly mutant mice and subsequent selection of animals showing symptoms equivalent to human kidney diseases may result in the generation of novel suitable models for the study of the pathomechanisms and the identification of genes involved in kidney dysfunction. Methods: We carried out a large-scale analysis of ethylnitrosourea (ENU)-induced mouse mutants for albuminuria by using qualitative SDS-polyacrylamide gel electrophoresis. Results: The primary albuminuria screen preceded the comprehensive phenotypic mutation analysis in a part of the mice of the Munich ENU project to avoid loss of mutant animals as a consequence of prolonged suffering from severe nephropathy. The primary screen detected six confirmed phenotypic variants in 2,011 G1 animals screened for dominant mutations and no variant in 48 G3 pedigrees screened for recessive mutations. Further breeding experiments resulted in two lines showing a low phenotypic penetrance of albuminuria. The secondary albuminuria screen was carried out in mutant lines which were established in the Munich ENU project without preceding primary albuminuria analysis. Two lines showing increased plasma urea levels were chosen to clarify if severe kidney lesions are involved in the abnormal phenotype. This analysis revealed severe albuminuria in mice which are affected by a recessive mutation leading to increased plasma urea and cholesterol levels. Conclusion: Thus, the phenotypic selection of ENU-induced mutants according to the parameter proteinuria in principle demonstrates the feasibility to identify nephropathy phenotypes in ENU-mutagenized mice. Copyright (C) 2005 S. Karger AG, Basel
Saturation of Turbulent Drag Reduction in Dilute Polymer Solutions
Drag reduction by polymers in turbulent wall-bounded flows exhibits universal
and non-universal aspects. The universal maximal mean velocity profile was
explained in a recent theory. The saturation of this profile and the crossover
back to the Newtonian plug are non-universal, depending on Reynolds number Re,
concentration of polymer and the degree of polymerization . We
explain the mechanism of saturation stemming from the finiteness of
extensibility of the polymers, predict its dependence on and in the
limit of small and large Re, and present the excellent comparison of our
predictions to experiments on drag reduction by DNA.Comment: 4 pages, 4 figs., included, PRL, submitte
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