757 research outputs found
Browser-based Analysis of Web Framework Applications
Although web applications evolved to mature solutions providing sophisticated
user experience, they also became complex for the same reason. Complexity
primarily affects the server-side generation of dynamic pages as they are
aggregated from multiple sources and as there are lots of possible processing
paths depending on parameters. Browser-based tests are an adequate instrument
to detect errors within generated web pages considering the server-side process
and path complexity a black box. However, these tests do not detect the cause
of an error which has to be located manually instead. This paper proposes to
generate metadata on the paths and parts involved during server-side processing
to facilitate backtracking origins of detected errors at development time.
While there are several possible points of interest to observe for
backtracking, this paper focuses user interface components of web frameworks.Comment: In Proceedings TAV-WEB 2010, arXiv:1009.330
Running Neutrino Mass Parameters in See-Saw Scenarios
We systematically analyze quantum corrections in see-saw scenarios, including
effects from above the see-saw scales. We derive approximate renormalization
group equations for neutrino masses, lepton mixings and CP phases, yielding an
analytic understanding and a simple estimate of the size of the effects. Even
for hierarchical masses, they often exceed the precision of future experiments.
Furthermore, we provide a software package allowing for a convenient numerical
renormalization group analysis, with heavy singlets being integrated out
successively at their mass thresholds. We also discuss applications to model
building and related topics.Comment: 49 pages, 9 figures; minor corrections in Sec. 6.5.1; the
accompanying software packages REAP/MPT can be downloaded from
http://www.ph.tum.de/~rg
The LMA Solution from Bimaximal Lepton Mixing at the GUT Scale by Renormalization Group Running
We show that in see-saw models with bimaximal lepton mixing at the GUT scale
and with zero CP phases, the solar mixing angle theta_{12} generically evolves
towards sizably smaller values due to Renormalization Group effects, whereas
the evolution of theta_{13} and theta_{23} is comparatively small. The
currently favored LMA solution of the solar neutrino problem can thus be
obtained in a natural way from bimaximal mixing at the GUT scale. We present
numerical examples for the evolution of the leptonic mixing angles in the
Standard Model and the MSSM, in which the current best-fit values of the LMA
mixing angles are produced. These include a case where the mass eigenstates
corresponding to the solar mass squared difference have opposite CP parity.Comment: 14 pages, 10 figures; references and a subsection containing an
example with odd CP parities added; results and conclusions unchange
Neutrino Mass Operator Renormalization in Two Higgs Doublet Models and the MSSM
In a recent re-analysis of the Standard Model (SM) beta-function for the
effective neutrino mass operator, we found that the previous results were not
entirely correct. Therefore, we consider the analogous dimension five operators
in a class of Two Higgs Doublet Models (2HDM's) and the Minimal Supersymmetric
Standard Model (MSSM). Deriving the renormalization group equations for these
effective operators, we confirm the existing result in the case of the MSSM.
Some of our 2HDM results are new, while others differ from earlier
calculations. This leads to modifications in the renormalization group
evolution of leptonic mixing angles and CP phases in the 2HDM's.Comment: 8 pages, 18 eps figure
Renormalization Group Analysis of Neutrino Mass Parameters
Tools for calculating the Renormalization Group Equations for renormalizable
and non-renormalizable operators in various theories are reviewed, which are
essential for comparing experimental results with predictions from models
beyond the Standard Model. Numerical examples for the running of the lepton
mixing angles in models with non-degenerate see-saw scales are shown, in which
the best-fit values of the experimentally favored LMA solution are produced
from maximal or from vanishing solar neutrino mixing at the GUT scale.Comment: 6 pages, 17 figures; to appear in the proceedings of the 10th
International Conference on Supersymmetry and Unification of Fundamental
Interactions (SUSY02), June 17 - 23, DESY Hambur
Neutrino Mass Operator Renormalization Revisited
We re-derive the renormalization group equation for the effective coupling of
the dimension five operator which corresponds to a Majorana mass matrix for the
Standard Model neutrinos. We find a result which differs somewhat from earlier
calculations, leading to modifications in the evolution of leptonic mixing
angles and CP phases. We also present a general method for calculating
beta-functions from counterterms in MS-like renormalization schemes, which
works for tensorial quantities.Comment: 9 pages, 2 figures, references update
Competitive Scavenging of Trace Metals by HFO and HMO during Redox-driven Early Diagenesis of Ferromanganese Nodules (11 pp)
-: Dedicated to Prof. Dr. Ulrich Förstner on his 65th birthday Background: Surface complexation models (SCM) alone have yet less successfully reproduced sorption isotherms of hydrous manganese oxides (HMO). This is in part due to the fact that the HMO structure may vary with pH, and also because microbially formed natural HMO has an oxidation number O/Mn 〈 2, i.e. is of non-stoichiometrical composition. The former effect has often led to severe artefacts, such as an under-prediction of metal sequestration at low pH, and non-comparable pK and pHZPC values in literature. The latter effect is of particular importance for environments of varying redox conditions like sediments. Objectives: We propose therefore a new sorption model comprising of amphoteric site SCM, ion exchange due to permanent charge compensation, and solid solution formation, in order to comply at least in part with the redox complexity of HMO phases of stable birnessite- and buserite-type structures. Methods: The model is run by a new Gibbs energy minimization code which is shown to be particularly suitable for such a sorption continuum approach. Results and Discussion: Initial calibration of the model was performed by experimental literature data on simple laboratory systems. Thus parameterised, we simulated on the basis of available field data the effect of redox-driven dissolution of a ferromanganese nodule on the partitioning of metals between the interacting HMO, HFO, and marine water phases. Our scenario model suggests that significant fraction of Mn and other metals, probably 50% or more, may be recycled to water column from the surface of the ferromanganese nodule upon gradual development of the bottom water stagnation, except of Zn for which a by far stronger net retention was found. Conclusion and Outlook: Our model, even if only a first approximation, clearly shows that stagnation in the marine bottom water, once occurring, can drastically change primary element proxy records in ferromanganese nodules, smoothing out any anomalous patterns in the most recent recor
Controllers for Battery Chargers and Battery Chargers Therefrom
A controller for a battery charger that includes a power converter has parametric sensors for providing a sensed Vin signal, a sensed Vout signal and a sensed Iout signal. A battery current regulator (BCR) is coupled to receive the sensed Iout signal and an Iout reference, and outputs a first duty cycle control signal. An input voltage regulator (IVR) receives the sensed Vin signal and a Vin reference. The IVR provides a second duty cycle control signal. A processor receives the sensed Iout signal and utilizes a Maximum Power Point Tracking (MPPT) algorithm, and provides the Vin reference to the IVR. A selection block forwards one of the first and second duty cycle control signals as a duty cycle control signal to the power converter. Dynamic switching between the first and second duty cycle control signals maximizes the power delivered to the battery
Neutrino Mass Matrix Running for Non-Degenerate See-Saw Scales
We consider the running of the neutrino mass matrix in the Standard Model and
the Minimal Supersymmetric Standard Model, extended by heavy singlet Majorana
neutrinos. Unlike previous studies, we do not assume that all of the heavy mass
eigenvalues are degenerate. This leads to various effective theories when the
heavy degrees of freedom are integrated out successively. We calculate the
Renormalization Group Equations that govern the evolution of the neutrino mass
matrix in these effective theories. We show that an appropriate treatment of
the singlet mass scales can yield a substantially different result compared to
integrating out the singlets at a common intermediate scale.Comment: 12 pages, 9 figure
Multi-phase classification by a least-squares support vector machine approach in tomography images of geological samples
Image processing of X-ray-computed polychromatic cone-beam micro-tomography (µXCT) data of geological samples mainly involves artefact reduction and phase segmentation. For the former, the main beam-hardening (BH) artefact is removed by applying a best-fit quadratic surface algorithm to a given image data set (reconstructed slice), which minimizes the BH offsets of the attenuation data points from that surface. A Matlab code for this approach is provided in the Appendix. The final BH-corrected image is extracted from the residual data or from the difference between the surface elevation values and the original grey-scale values. For the segmentation, we propose a novel least-squares support vector machine (LS-SVM, an algorithm for pixelbased multi-phase classification) approach. A receiver operating characteristic (ROC) analysis was performed on BHcorrected and uncorrected samples to show that BH correction is in fact an important prerequisite for accurate multiphase classification. The combination of the two approaches was thus used to classify successfully three different more or less complex multi-phase rock core samples
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