19,588 research outputs found
Potential and availability of market research data for empirical social and economic research
The potential of market research data for secondary analyses lays mainly in the fields of consumer behaviour, consumption patterns and media usage. Their availability for empirical social and economic research depends on the professional rules as well as on the readiness of the market research agencies and their clients to make them available. Many market research projects are focused on specific target groups. This focuses their potential for secondary analyses on representative insights regarding these groups as well as on basic and methodological research. In most cases it is necessary that public availability of market research data is agreed contractually with the client of the research project. For a number of market research projects access to the official statistical data is important for methodological reasons. Therefore private research agencies should have the same privileged access to them as academic research institutions. As long as this access has not been established it is unlikely that their readiness to make market research data publicly available will increase.
Concept for sleeve induction motor with 1-msec mechanical time constant
Conductive sleeve induction motor having a 1-msec mechanical time constant is used with solid-state devices to control all-electric servo power systems. The servomotor rotor inertia is small compared to the maximum force rating of the servo motion, permitting high no-load acceleration
Renormalization and ultraviolet sensitivity of gauge vertices in universal extra dimensions
When computing radiative corrections in models with compactified extra dimen-
sions, one has to sum over the entire tower of Kaluza-Klein excitations inside
the loops. The loop corrections generate a difference between the coupling
strength of a zero-mode gauge boson and the coupling strength of its
Kaluza-Klein excitation, although both originate from the same
higher-dimensional gauge interaction. Furthermore, this dis- crepancy will in
general depend on the cutoff scale and assumptions about the UV completion of
the extra-dimensional theory. In this article, these effects are studied in
detail within the context of the minimal universal extra dimension model
(MUED). The broad features of the cutoff scale dependence can be captured
through the so- lution of the functional flow equation in five-dimensional
space. However, an explicit diagrammatic calculation reveals some modifications
due to the compactification of the extra dimension. Nevertheless, when imposing
a physical renormalization condition, one finds that the UV sensitivity of the
effective Kaluza-Klein gauge-boson vertex is relatively small and not very
important for most phenomenological purposes. Similar conclusions should hold
in a larger class of extra-dimensional models besides MUED.Comment: 20 pages, 5 figure
Multiscale approach to inhomogeneous cosmologies
The backreaction of inhomogeneities on the global expansion history of the
Universe suggests a possible link of the formation of structures to the recent
accelerated expansion. In this paper, the origin of this conjecture is
illustrated and a model without Dark Energy that allows for a more explicit
investigation of this link is discussed. Additionally to this conceptually
interesting feature, the model leads to a LCDM-like distance-redshift relation
that is consistent with SN data.Comment: 5 pages, 4 figures, contributed talk at the Workshop: New Directions
in Modern Cosmology, Leiden, The Netherlands, 27.9.-1.10. (2010
Relativistic Lagrangian displacement field and tensor perturbations
We investigate the purely spatial Lagrangian coordinate transformation from
the Lagrangian to the basic Eulerian frame. We demonstrate three techniques for
extracting the relativistic displacement field from a given solution in the
Lagrangian frame. These techniques are (a) from defining a local set of
Eulerian coordinates embedded into the Lagrangian frame; (b) from performing a
specific gauge transformation; and (c) from a fully non-perturbative approach
based on the ADM split. The latter approach shows that this decomposition is
not tied to a specific perturbative formulation for the solution of the
Einstein equations. Rather, it can be defined at the level of the
non-perturbative coordinate change from the Lagrangian to the Eulerian
description. Studying such different techniques is useful because it allows us
to compare and develop further the various approximation techniques available
in the Lagrangian formulation. We find that one has to solve the gravitational
wave equation in the relativistic analysis, otherwise the corresponding
Newtonian limit will necessarily contain spurious non-propagating tensor
artefacts at second order in the Eulerian frame. We also derive the magnetic
part of the Weyl tensor in the Lagrangian frame, and find that it is not only
excited by gravitational waves but also by tensor perturbations which are
induced through the non-linear frame-dragging. We apply our findings to
calculate for the first time the relativistic displacement field, up to second
order, for a CDM Universe in the presence of a local primordial
non-Gaussian component. Finally, we also comment on recent claims about whether
mass conservation in the Lagrangian frame is violated.Comment: 19 pages, two figures, improved discussion, matches published versio
Irrigation scheduling, freeze warning, and soil salinity detecting
There are no author-identified significant results in this report
Hypersurfaces of bounded Cohen--Macaulay type
Let R = k[[x_0,...,x_d]]/(f), where k is a field and f is a non-zero non-unit
of the formal power series ring k[[x_0,...,x_d]]. We investigate the question
of which rings of this form have bounded Cohen--Macaulay type, that is, have a
bound on the multiplicities of the indecomposable maximal Cohen--Macaulay
modules. As with finite Cohen--Macaulay type, if the characteristic is
different from two, the question reduces to the one-dimensional case: The ring
R has bounded Cohen--Macaulay type if and only if R is isomorphic to
k[[x_0,...,x_d]]/(g+x_2^2+...+x_d^2), where g is an element of k[[x_0,x_1]] and
k[[x_0,x_1]]/(g) has bounded Cohen--Macaulay type. We determine which rings of
the form k[[x_0,x_1]]/(g) have bounded Cohen--Macaulay type.Comment: 16 pages, referee's suggestions and correction
Reflectance of vegetation, soil, and water
There are no author-identified significant results in this report
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