SeismicWaveTool: Continuous and discrete wavelet analysis and filtering for multichannel seismic data

A MATLAB-based computer code has been developed for the simultaneous wavelet analysis and filtering of multichannel seismic data. The considered time–frequency transforms include the continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform. The developed approaches provide a fast and precise time–frequency examination of the seismograms at different frequency bands. Moreover, filtering methods for noise, transients or even baseline removal, are implemented. The primary motivation is to support seismologists with a user-friendly and fast program for the wavelet analysis, providing practical and understandable results.

A Matrix PRNG with S-Box Output Filtering

We describe a modification to a previously published pseudorandom number generator improving security while maintaining high performance. The proposed generator is based on the powers of a word-packed block upper triangular matrix and it is designed to be fast and easy to implement in software since it mainly involves bitwise operations between machine registers and, in our tests, it presents excellent security and statistical characteristics. The modifications include a new, key-derived s-box based nonlinear output filter and improved seeding and extraction mechanisms. This output filter can also be applied to other generators.

On the decorrelation filtering of RL05 GRACE data for global applications

In autumn 2012, the new release 05 (RL05) of monthly geopotencial spherical harmonics Stokes coefficients (SC) from GRACE (Gravity Recovery and Climate Experiment) mission was published. This release reduces the noise in high degree and order SC, but they still need to be filtered. One of the most common filtering processing is the combination of decorrelation and Gaussian filters. Both of them are parameters dependent and must be tuned by the users. Previous studies have analyzed the parameters choice for the RL05 GRACE data for oceanic applications, and for RL04 data for global application. This study updates the latter for RL05 data extending the statistics analysis. The choice of the parameters of the decorrelation filter has been optimized to: (1) balance the noise reduction and the geophysical signal attenuation produced by the filtering process; (2) minimize the differences between GRACE and model-based data; (3) maximize the ratio of variability between continents and oceans. The Gaussian filter has been optimized following the latter criteria. Besides, an anisotropic filter, the fan filter, has been analyzed as an alternative to the Gauss filter, producing better statistics.

EnvironmentalWaveletTool: Continuous and discrete wavelet analysis and filtering for environmental time series

A MATLAB-based computer code has been developed for the simultaneous wavelet analysis and filtering of several environmental time series, particularly focused on the analyses of cave monitoring data. The continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform have been implemented to provide a fast and precise time–period examination of the time series at different period bands. Moreover, statistic methods to examine the relation between two signals have been included. Finally, the entropy of curves and splines based methods have also been developed for segmenting and modeling the analyzed time series. All these methods together provide a user-friendly and fast program for the environmental signal analysis, with useful, practical and understandable results.

The Convention on the Future of Europe: Extended Working Group or Constitutional Assembly? Research Papers in Law, 4/2005

From the Introduction. “We are a Convention. We are not an Intergovernmental Conference because we have not been given a mandate by Governments to negotiate on their behalf the solutions which we propose. We are not a Parliament because we are not elected by citizens to draft legislative texts. […] We are a Convention. What does this mean? A Convention is a group of men and women meeting for the sole purpose of preparing a joint proposal. […] It is a task modest in form but immense in content, for if it succeeds in accordance with our mandate, it will light up the future of Europe”.1 In his speech inaugurating the Convention process on 26 February 2002 in Brussels, Convention President VALÉRY GISCARD D’ESTAING raises three issues: first, he refers to the Convention’s nature and method; second, he talks of the Convention’s aim and output; and, third, he evokes the Convention’s historic and symbolic significance. All three aspects have been amply discussed in the past two years by politicians and academics analysing whether the Convention’s purpose and instruments differ fundamentally from those of previous reform rounds; whether the input into and output of the Convention process qualitatively improves European Treaty revision; and whether the Convention as an institution lived up to its symbolic and normative load, reflected in comparisons with “Philadelphia” or references to a “constitutional moment”.2