120,284 research outputs found
Computing the Cramer-Rao bound of Markov random field parameters: Application to the Ising and the Potts models
No full textThis letter considers the problem of computing the Cramer–Rao bound for the parameters of a Markov random field. Computation of the exact bound is not feasible for most fields of interest because their likelihoods are intractable and have intractable derivatives. We show here how it is possible to formulate the computation of the bound as a statistical inference problem that can be solve approximately, but with arbitrarily high accuracy, by using a Monte Carlo method. The proposed methodology is successfully applied on the Ising and the Potts models
La Périchole : deux bouquets de mélodies pour le piano. [N°1] / mosaïques de Cramer ; [d'après l']opéra-bouffe de J. Offenbach ; [ill. par] A. Jannin
No full textTitre uniforme : Cramer, Henri (18..-1877). Compositeur. [Arrangements. Offenbach, Jacques. La Périchole. Piano]Piano, Musique de -- +* 1800......- 1899......+:19e siècle
L'ombre : deux bouquets de mélodies. [N°1] / mosaïque pour piano par Cramer ; [d'après l']opéra comique de F. de Flotow ; [ill. par] A. Jannin
No full textTitre uniforme : Cramer, Henri (18..-1877). Compositeur. [Arrangements. Flotow, Friedrich. L'ombre. Piano]Piano, Musique de -- +* 1800......- 1899......+:19e siècle
L'Africaine : mosaïque pour piano. bouquet de mélodies [N°1] / par Cramer ; [d'après l']opéra de G. Meyerbeer ; [ill. par] A. Barbizet,...
No full textTitre uniforme : Cramer, Henri (18..-1877). Compositeur. [Arrangements. Meyerbeer, Giacomo. L'Africaine. Piano]Piano, Musique de -- +* 1800......- 1899......+:19e siècle
Quantum Chemical Characterization of the Bonding of N-Heterocyclic Carbenes to Cp2MI Compounds [M = Ce(III), U(III)]
No full textThe binding of N-heterocyclic carbenes to Ce(III) and U(III) compounds is characterized by quantum chemical methods. Density functional methods are in qualitative agreement with experiment that binding to U(III) is more favorable than to Ce(III); after correcting for basis-set superposition error, quantitative agreement with experiment is achieved with a multireference second-order perturbation theory approach accounting for relativistic effects. The small computed (and observed) preference derives from a combination of several small effects, including differences in electronic binding energies, rovibrational partition functions, and solvation free energies. Prospects for ligand modification to improve the differentiation between lanthanides and actinides are discussed on the basis of computational predictions
N and P limitation of fynbos plants and the nutritional status of legume habitats in the Cape Floristic Region
No full textIn general, terrestrial ecosystems are limited by both N and P, but, as legumes fix atmospheric nitrogen, I hypothesized that fynbos legumes would be P limited and nonlegumes would be N limited, and that the degree to which these plants respond to N and P would depend on the levels of each of these two nutrients in the growth media. To test these hypotheses, three legumes and three non-legumes native to the fynbos were grown in a complete factorial arrangement of four levels of N and P in a glass house. Nitrogen was supplied at 20, 40, 80 and 150 mg kg-¹ soil and P at 0.8, 5, 15, and 31 mg kg-¹. Overall, the results showed that the responses of the legume and nonlegume species to N and P supply were species specific, but that the legume species seemed to be more limited by N supply than the non-legumes. There was no N x P interaction in this study, which implied that the plant response to N and P, did not depend on the levels of each other. Given the nitrogen fixing capabilities of legumes and high nutrient demanding lifestyle, I made the hypothesis that, on a given landscape, the soils on which the fynbos legumes occur were more nutrient rich than the bulk non-legume soils. Related to this hypothesis is the question of whether the more nutrient rich soils within the legume populations would be mirrored by leaves with both a higher specific leaf area and higher nutrient concentration, than the leaves of the non-legumes. To test these hypotheses, I determined the nutrient levels of both the soils and plants within both the legume- and non-legumes stands at eight different sites in the CFR. The data were subjected to multifactorial discriminant function analysis and Nested ANOVA analyses. The results of the analyses led to the conclusion that the soil on which legume stands occurred were rarely more fertile than the non-legumes on the landscape in the CFR, and, except for leaf N, there seemed to be no differences between leaf nutrient concentrations and the SLA of the legume and non-legume plants
An Extended Winged Helix Domain in General Transcription Factor E/IIE&alpha
No full textInitiation of eukaryotic mRNA transcription requires melting of promoter DNA with the help of the general transcription factors TFIIE and TFIIH. Here we define a conserved and functionally essential N−terminal domain in TFE, the archaeal homolog of the large TFIIE subunit {alpha}. X−ray crystallography shows that this TFE domain adopts a winged helix−turn−helix (winged helix) fold, extended by specific {alpha}−helices at the N and C termini. Although the winged helix fold is often found in DNA−binding proteins, we show that TFE is not a typical DNA−binding winged helix protein, because its putative DNA−binding face shows a negatively charged groove and an unusually long wing, and because the domain lacks DNA−binding activity in vitro. The groove and a conserved hydrophobic surface patch on the additional N−terminal {alpha}−helix may, however, allow for interactions with other general transcription factors and RNA polymerase. Homology modeling shows that the TFE domain is conserved in TFIIE{alpha}, including the potential functional surface
Cramer-von Mises and Anderson-Darling goodness of fit tests for extreme value distributions with unknown parameters
No full textThe use of goodness of fit tests based on Cramer-von Mises and Anderson-Darling statistics is discussed, with reference to the composite hypothesis that a sample of observations comes from a distribution, FH, whose parameters are unspecified. When this is the case, the critical region of the test has to be redetermined for each hypothetical distribution FH. To avoid this difficulty, a transformation is proposed that produces a new test statistic which is independent of FH. This transformation involves three coefficients that are determined using the asymptotic theory of tests based on the empirical distribution function. A single table of coefficients is thus sufficient for carrying out the test with different hypothetical distributions; a set of probability models of common use in extreme value analysis is considered here, including the following: extreme value 1 and 2, normal and lognormal, generalized extreme value, three-parameter gamma, and log-Pearson type 3, in all cases with parameters estimated using maximum likelihood. Monte Carlo simulations are used to determine small sample corrections and to assess the power of the tests compared to alternative approaches
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Título: Additiones et observationes ad Castillum de Alimentis cum S. Rotae Romanae decisionibus
No full textMarca tip. xil. na portSign.: A-M, N-O, a-v, x, y, A-S, GTexto a duas co
- …
