The Sinkhorn-Knopp algorithm : convergence and applications

As long as a square nonnegative matrix A contains sufficient nonzero elements, then the Sinkhorn-Knopp algorithm can be used to balance the matrix, that is, to find a diagonal scaling of A that is doubly stochastic. It is known that the convergence is linear, and an upper bound has been given for the rate of convergence for positive matrices. In this paper we give an explicit expression for the rate of convergence for fully indecomposable matrices. We describe how balancing algorithms can be used to give a measure of web page significance. We compare the measure with some well known alternatives, including PageRank. We show that, with an appropriate modi. cation, the Sinkhorn-Knopp algorithm is a natural candidate for computing the measure on enormous data sets

Density Fluctuations in an Electrolyte from Generalized Debye-Hueckel Theory

Near-critical thermodynamics in the hard-sphere (1,1) electrolyte is well described, at a classical level, by Debye-Hueckel (DH) theory with (+,-) ion pairing and dipolar-pair-ionic-fluid coupling. But DH-based theories do not address density fluctuations. Here density correlations are obtained by functional differentiation of DH theory generalized to {\it non}-uniform densities of various species. The correlation length $\xi$ diverges universally at low density $\rho$ as $(T\rho)^{-1/4}$ (correcting GMSA theory). When $\rho=\rho_c$ one has $\xi\approx\xi_0^+/t^{1/2}$ as $t\equiv(T-T_c)/T_c\to 0+$ where the amplitudes $\xi_0^+$ compare informatively with experimental data.Comment: 5 pages, REVTeX, 1 ps figure included with epsf. Minor changes, references added. Accepted for publication in Phys. Rev. Let

Envelope Surfaces, Surface Design and Meshing

Voor het ontwerpen van producten wordt veel gebruik gemaakt van computerprogramma's die driedimensionale modellen kunnen maken met een soort virtuele klei. Met zo'n model wordt het product zichtbaar, maar het model kan ook worden gebruikt voor het testen van het product. Bekend zijn de voorbeelden uit de auto- en luchtvaartindustrie, maar ook gewone consumentenproducten worden met behulp van deze modellen ontwikkeld. Nico Kruithof beschrijft in zijn proefschrift een nieuwe methode voor het modelleren van zulke oppervlakken en beschrijft de wiskundige methoden die eraan ten grondslag liggen

Het nieuwe zekerheidsrecht

Dit boek bevat de verslagen van de studieavond van 24 oktober 2013 over de hervorming van het zekerheidsrecht door de wet van 11 juli 2013

Magnetotransport with two occupied subbands in a Si(100) inversion layer

We have studied an electron transport in inversion layers of high-mobility Si(100) samples. At high electron concentrations and temperatures below 4.2 K, two series of Shubnikov-de Haas oscillations have been observed. The temperature damping of the second series oscillations indicates that the second occupied subband belongs to the first energy level of the fourfold-degenerate ladder $0'$. Samples with two occupied subbans exhibit a strong anomalous negative magnetoresitance, reaching $\rm \approx 25 \%$ of a zero field value at $B =$ 12 T. The resistance decrease is more pronounced for lower temperatures and higher electron concentrations. We explain this behaviour by an increase of the second subband mobility due to the freezing-out of the scattering of $0'$ electrons. Based on the measured periods of SdH oscillations, we conclude that the electrons are distributed inhomogeneously beneath the sample gate.Comment: 4 pages. RevTex text and 4 PostScript figures in a single tar-compressed file produced by 'uufiles

IMMIGRACIÓN Y POLÍTICAS DE PARTICIPACIÓN EN EL ÁREA METROPOLITANA DE VALÈNCIA

El objetivo de este proyecto de investigación es identificar los mecanismos de participación disponibles para la comunidad de extranjeros asentada en la ciudad de València. Una breve introducción y descripción de los conceptos utilizados será seguida del análisis de la regulación local, principalmente los Planes de Integración valencianos, así como los organismos derivados de ella. La segunda fase presenta un análisis crítico de la situación, mostrando los puntos fuertes y débiles de las políticas de participación dirigidas a los inmigrantes. Este artículo intentará demostrar que el resultado de estas políticas no se corresponde con las intenciones de Planes, sugiriendo que no ha sido una prioridad para las autoridades públicas. Finalmente, se presentarán recomendaciones para el futuro, apostando por una mayor inclusión de los recién llegados en la vida pública

Epigenetic control of tissue-type plasminogen activator synthesis in human endothelial cells

Aims Tissue-type plasminogen activator (t-PA) is produced by endothelial cells (EC) and is responsible for the removal of intravascular fibrin deposits. We investigated whether expression of t-PA by EC is under epigenetic control. Methods and results Methylation analysis of the proximal t-PA promoter revealed a stretch of unmethylated CpG dinucleotides from position −121 to +59, while upstream CpG dinucleotides were all methylated. In contrast, in human primary hepatocytes, which express t-PA at much lower levels than EC, the proximal promoter was partially methylated. Treatment of EC with the non-specific histone deacetylase (HDAC) inhibitors butyrate and trichostatin and with MS275, a specific inhibitor of class I HDAC, resulted in a time- and dose-dependent increase in t-PA expression. Garcinol and anacardic acid, inhibitors of the histone acetyl transferases CBP/p300 and PCAF, reduced basal and HDAC inhibitor-induced t-PA expression, whereas curcumin, an inhibitor of CBP/p300 only, had no effect. We performed chromosome immunoprecipitation analysis of the t-PA promoter using antibodies specific for acetylated histone H3 or H4 and observed an increase in H3 acetylation of 10 ± 3 and 44 ± 14-fold in EC treated with trichostatin or MS275, respectively, and in H4 acetylation of 7.7 ± 1.4 and 16 ± 3-fold, respectively. Conclusion The proximal t-PA promoter is unmethylated in human EC and partially methylated in human primary hepatocytes. Expression of t-PA by EC is repressed by HDACs in a mechanism that involves de-acetylation of histone H3 and H