Learning Probability Measures with respect to Optimal Transport Metrics

We study the problem of estimating, in the sense of optimal transport metrics, a measure which is assumed supported on a manifold embedded in a Hilbert space. By establishing a precise connection between optimal transport metrics, optimal quantization, and learning theory, we derive new probabilistic bounds for the performance of a classic algorithm in unsupervised learning (k-means), when used to produce a probability measure derived from the data. In the course of the analysis, we arrive at new lower bounds, as well as probabilistic upper bounds on the convergence rate of the empirical law of large numbers, which, unlike existing bounds, are applicable to a wide class of measures.Comment: 13 pages, 2 figures. Advances in Neural Information Processing Systems, NIPS 201

Weak line water vapor spectrum in the 13 200–15 000 cm−1 region

New Fourier transform spectra of water vapor are presented in the range 6500–16 400 cm−1 obtained using pathlengths of up to 800 m and long integration times. These spectra have a significantly higher signal-to-noise than previous measurements in this wavenumber range. Wavenumbers, absolute intensities and self-broadening coefficients, all with associated uncertainties, are presented for 3604 lines in the region 13 200–15 000 cm−1. Analysis of these lines using variational linelists, along with other unassigned lines from previous studies, has been conducted. This leads to 952 new line assignments to transitions involving 35 different vibrational states of H216O. A smaller number of lines are assigned to H218O and H217O

Teores de metanol em aguardentes vínicas e bagaceiras portuguesas

Comunicação apresentada no 8.º Simpósio de Vitivinicultura do Alentejo que decorreu em Évora de 5 a 7 de Maio de 2010.O metanol é um álcool resultante da degradação das pectinas que ocorre durante o processo de fermentação do vinho e do bagaço, passando para a aguardente durante o processo de destilação. A tecnologia utilizada na preparação dos vinhos e dos bagaços condiciona o seu teor nos destilados. Por razões de toxicidade, o teor de metanol nas aguardentes é limitado a 1000g/hL de álcool puro nas aguardentes bagaceiras e 200g/hL nas aguardentes vínicas (Reg. CE. 110/2008). Assim, antes da colocação das aguardentes no mercado deve ser avaliado o teor deste álcool, o qual é normalmente quantificado por cromatografia-gáslíquido de alta resolução. Neste trabalho são apresentados os teores de metanol de um número considerável de amostras analisadas no nosso laboratório, em 2007, 2008 e 2009. Os resultados obtidos mostram que nenhuma das amostras de aguardente vínica analisada apresentou um teor superior ao limite legal estabelecido. No caso das aguardentes bagaceiras, apenas quatro das amostras analisadas apresentaram teores acima do limite legal

Fractal behaviour of the seismicity in the Southern Iberian Peninsula

The fractal behaviour of the seismicity in the Southern Iberian Peninsula is analysed by considering two different series of data: the distance and the elapsed time between consecutive seismic events recorded by the seismic network of the Andalusian Institute of Geophysics (AIG). The fractal analyses have been repeated by considering four threshold magnitudes of 2.5, 3.0, 3.5 and 4.0. The re-scaled analysis lets to determine if the seismicity shows strong randomness or if it is characterised by time-persistence and the cluster dimension indicates the degree of time and spatial clustering of the seismicity. Another analysis, based on the reconstruction theorem, permits to evaluate the minimum number of nonlinear equations describing the dynamical mechanism of the seismicity, its 'loss of memory', its chaotic character and the instability of a possible predicting algorithm. The results obtained depict some differences depending on distances or elapsed times and the different threshold levels of magnitude also lead to slightly different results. Additionally, only a part of the fractal tools, the re-scaled analysis, have been applied to five seismic crises in the same area

Archaeo-Astronomy in Society: Supporting Citizenship in Schools Across Europe

The interdisciplinary topic of archaeo-astronomy links science subjects such as astronomy with archaeology and sociology to explore how ancient societies perceived the heavens above. This is achieved by analysing ancient sites such as megalithic monuments (e.g. Stonehenge), since they are the most common remains of these societies and are wide spread in Europe. We discuss how archaeo-astronomy and ancient sites can be transversal to many topics in school. The links to the science curricula in different countries are highlighted. However, especially the subject of citizenship can be supported by exploring the diversity of culture, ideas, and identities including the changing nature of society in the past millennia. We conclude that archaeo-astronomy offers many opportunities for citizenship. Learning more about megalithic monuments in different countries (e.g. England, Portugal, and Germany) supports tolerance and understanding. Furthermore, the distribution of these sites lends itself to explore beyond borders, introduce international networking, and truly develop students into global citizens.Comment: 9 pages, 4 Figures, submitted to Science in Societ

KELT-7b: A hot Jupiter transiting a bright V=8.54 rapidly rotating F-star

We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of $1.28 \pm 0.18$ MJ, radius of $1.53_{-0.047}^{+0.046}$ RJ, and an orbital period of $2.7347749 \pm 0.0000039$ days. The bright host star (HD33643; KELT-7) is an F-star with $V=8.54$, Teff $=6789_{-49}^{+50}$ K, [Fe/H] $=0.139_{-0.081}^{+0.075}$, and $\log{g}=4.149 \pm 0.019$. It has a mass of $1.535_{-0.054}^{+0.066}$ Msun, a radius of $1.732_{-0.045}^{+0.043}$ Rsun, and is the fifth most massive, fifth hottest, and the ninth brightest star known to host a transiting planet. It is also the brightest star around which KELT has discovered a transiting planet. Thus, KELT-7b is an ideal target for detailed characterization given its relatively low surface gravity, high equilibrium temperature, and bright host star. The rapid rotation of the star ($73 \pm 0.5$ km/s) results in a Rossiter-McLaughlin effect with an unusually large amplitude of several hundred m/s. We find that the orbit normal of the planet is likely to be well-aligned with the stellar spin axis, with a projected spin-orbit alignment of $\lambda=9.7 \pm 5.2$ degrees. This is currently the second most rapidly rotating star to have a reflex signal (and thus mass determination) due to a planetary companion measured.Comment: Accepted to The Astronomical Journa