All you can measure at the Planetary Emissivity Laboratory (PEL) at DLR, in Berlin

The Institute for Planetary Research has an expertise in spectroscopy of minerals, rocks, meteorites, and organic matter, build up in more than two decades. The available equipment allows spectroscopy from the visible to TIR range using bi-conical reflection, transmission and emission spectroscopy. The institute has an outstanding heritage in designing and building infrared remote-sensing instruments for planetary missions. The PEL has been operating in various configurations for the last 10 years. The laboratory experimental facilities consist of the main emissivity spectrometer laboratory, a supporting spectrometer laboratory for reflectance and transmission measurements, sample preparation facilities and an extensive collection of rocks and minerals

Synthetic speech detection and audio steganography in VoIP scenarios

The distinction between synthetic and human voice uses the techniques of the current biometric voice recognition systems, which prevent that a person’s voice, no matter if with good or bad intentions, can be confused with someone else’s. Steganography gives the possibility to hide in a file without a particular value (usually audio, video or image files) a hidden message in such a way as to not rise suspicion to any external observer. This article suggests two methods, applicable in a VoIP hypothetical scenario, which allow us to distinguish a synthetic speech from a human voice, and to insert within the Comfort Noise a text message generated in the pauses of a voice conversation. The first method takes up the studies already carried out for the Modulation Features related to the temporal analysis of the speech signals, while the second one proposes a technique that derives from the Direct Sequence Spread Spectrum, which consists in distributing the signal energy to hide on a wider band transmission. Due to space limits, this paper is only an extended abstract. The full version will contain further details on our research

Computation of the inverse Laplace Transform based on a Collocation method which uses only real values

We develop a numerical algorithm for inverting a Laplace transform (LT), based on Laguerre polynomial series expansion of the inverse function under the assumption that the LT is known on the real axis only. The method belongs to the class of Collocation methods (C-methods), and is applicable when the LT function is regular at infinity. Difficulties associated with these problems are due to their intrinsic ill-posedness. The main contribution of this paper is to provide computable estimates of truncation, discretization, conditioning and roundoff errors introduced by numerical computations. Moreover, we introduce the pseudoaccuracy which will be used by the numerical algorithm in order to provide uniform scaled accuracy of the computed approximation for any x with respect to ex . These estimates are then employed to dynamically truncate the series expansion. In other words, the number of the terms of the series acts like the regularization parameter which provides the trade-off between errors. With the aim to validate the reliability and usability of the algorithm experiments were carried out on several test functions

Conceptualización, registros de representaciones semióticas y noética: interacciones constructivistas en el aprendizaje de los conceptos matemáticos e hipótesis sobre algunos factores que inhiben la devolución

Este trabajo se inspira en los estudios en los que ha sido pionero indiscutible Raymond Duval (1988a, b, c; 1993), y se sitúa en la línea de investigación del nrd de Bolonia, que busca localizar y evidenciar las diferentes hipótesis que se hallan en la base de la falta de devolución (Perrin G., 1994), y por lo tanto en la base de la escolarización del saber matemático (D´Amore, 1999a)

Sobre algunas “D” en didáctica de la matemática: designación, denotación, denominación, definición, demostración. Reflexiones matemáticas y didácticas que pueden conducir lejos

En la acción normal del aula, existen momentos delicados a los cuales no se les presta atención por una clara falta de competencia; por ejemplo, no se estudian las acciones de designación, de denotación (y connotación), de denominación y de descripción, mientras que las operaciones de definición y de demostración en ocasiones se tienen bajo observación. En este breve texto se quiere llamar la atención sobre estos momentos matemáticos de gran importancia

Effect of Martian Suspended Dust on Albedo Measurements from the MGS-TES Data

Suspended dust on Mars influences albedo measurements by orbiting instruments, but not necessary the real surface albedo. The aim of this study is to characterize the role of suspended aerosols on albedo measurement by remote sensing instruments

New high-performance liquid chromatography-dad method for analytical determination of arbutin and hydroquinone in rat plasma

Natural substances present in herbal preparations should be carefully used because they can give toxic or therapeutic effects despite of their amount or the way of administration. The safety of products of vegetable origin must be assessed before commercialisation by monitoring the active ingredients and their metabolites. This study was therefore designed to identify and quantify arbutin and its metabolite hydroquinone, naturally present in Arctostaphylos uva-ursi (L.) Spreng plant in rat plasma, after an acute and subacute administration of aqueous arbutin solution in Wistar rats. For this purpose a reversed-phase high-performance liquid chromatography coupled with photodiode array detection was developed to assess the pharmacokinetic of arbutin and hydroquinone in plasma of female rats treated with aqueous arbutin solutions. The detection (arbutin: 0.0617 µg/ml and hydroquinone 0.0120 µg/ml) and quantification (arbutin: 0.2060 µg/ml and hydroquinone: 0.0400 µg/ml) limits were determined. At the arbutin concentration level of 10.7 µg/ml repeatability was 13.33% and its recovery 93.4±6.93%, while at the hydroquinone concentration level of 10.6 µg/ml repeatability was 11.66% and its recovery 92.9±7.75%. Furthermore the method was fully validated and the obtained data indicate that the new method provides good performances