Getting on top of things: form and meaning in the pseudo-Vergilian Aetna

This article offers a fresh view on the poetics of the pseudo-Vergilian poem Aetna, proposing a carefully planned and executed structure which is supported through a deliberate arrangement of key terms in the poem as well as a network of verbal cross-references

Pseudo-nonlinear and athermal lensing effects on transverse properties of Cr(3+) based solid-state lasers

Several experiments (time-resolved Z-scan experiments based on pulsed and CW pump lasers, time-resolved divergence diagnostics) have been performed to examine and clarify the question of the converging or diverging population lensing effect occurring in a Cr(3+):Al(2)O(3) ruby laser. The dynamics of the laser far-field divergence of such a laser indeed indicated initially a diverging effect while Z-scan measurements conclude to a converging one. The origin of this discrepancy is thus analysed and elucidated here by introducing the general concept of correlation collapse between the centre and the wings of a laser beam having some clipping. (C) 2010 Elsevier B.V. All rights reserved.

Regression analysis of mean quality-adjusted survival time based on pseudo-observations

Regression models for the mean quality-adjusted survival time are specified from hazard functions of transitions between two states and the mean quality-adjusted survival time may be a complex function of covariates. We discuss a regression model for the mean quality-adjusted survival (QAS) time based on pseudo-observations, which has the advantage of directly modeling the effect of covariates in the QAS time. Both Monte Carlo Simulations and a real data set are studied. Copyright (C) 2009 John Wiley & Sons, Ltd.

Pseudo Focal Points Along Lorentzian Geodesics and Morse Index

Given a Lorentzian manifold (M,g), a geodesic gamma in M and a timelike Jacobi field Y along gamma, we introduce a special class of instants along gamma that we call Y-pseudo conjugate (or focal relatively to some initial orthogonal submanifold). We prove that the Y-pseudo conjugate instants form a finite set, and their number equals the Morse index of (a suitable restriction of) the index form. This gives a Riemannian-like Morse index theorem. As special cases of the theory, we will consider geodesics in stationary and static Lorentzian manifolds, where the Jacobi field Y is obtained as the restriction of a globally defined timelike Killing vector field.

Examples from trees, related to discrete subsets, pseudo-radiality and omega-boundedness

We construct some examples using trees. Some of them are consistent counterexamples for the discrete reflection of certain topological properties. All the properties dealt with here were already known to be non-discretely reflexive if we assume CH and we show that the same is true assuming the existence of a Suslin tree. In some cases we actually get some ZFC results. We construct also, using a Suslin tree, a compact space that is pseudo-radial but it is not discretely generated. With a similar construction, but using an Aronszajn tree, we present a ZFC space that is first countable, omega-bounded but is not strongly w-bounded, answering a question of Peter Nyikos. (C) 2008 Elsevier B.V. All rights reserved.

Raman spectra of a pseudo-oxocarbon anion in ionic liquids

Raman and electronic spectra of the [3,5-bis(dicyanomethylene)cyclopentane-1,2,4-trionate] dianion, the croconate violet (CV), are reported in solutions of ionic liquids based on imidazolium cations. Different normal modes of the CV anion, nu (C=O), nu (CO) + nu (CC) + nu (CCN), and nu(C N), were used as probes of solvation characteristics of ionic liquids, and were compared with spectra of CV in common solvents. The spectra of CV in ionic liquids are similar to those in dichloromethane solution, but distinct from those in protic solvents such as ethanol or water. The UV-vis spectra of CV in ionic liquids strongly suggest pi-pi interactions between the CV anion and the imidazolium cation. Copyright (C) 2009 John Wiley & Sons, Ltd.

Generalized pseudo-likelihood estimates for markov random fields on lattice

In this paper we generalize Besag's pseudo-likelihood function for spatial statistical models on a region of a lattice. The correspondingly defined maximum generalized pseudo-likelihood estimates (MGPLEs) are natural extensions of Besag's maximum pseudo-likelihood estimate (MPLE). The MGPLEs connect the MPLE and the maximum likelihood estimate. We carry out experimental calculations of the MGPLEs for spatial processes on the lattice. These simulation results clearly show better performances of the MGPLEs than the MPLE, and the performances of differently defined MGPLEs are compared. These are also illustrated by the application to two real data sets.

A new re-ranking method using enhanced pseudo-relevance feedback for content-based medical image retrieval

We propose a novel re-ranking method for content-based medical image retrieval based on the idea of pseudo-relevance feedback (PRF). Since the highest ranked images in original retrieval results are not always relevant, a naive PRF based re-ranking approach is not capable of producing a satisfactory result. We employ a two-step approach to address this issue. In step 1, a Pearson's correlation coefficient based similarity update method is used to re-rank the high ranked images. In step 2, after estimating a relevance probability for each of the highest ranked images, a fuzzy SVM ensemble based approach is adopted to re-rank the images. The experiments demonstrate that the proposed method outperforms two other re-ranking methods.

Why web-based pseudo relevance feedback systems fail

 We review pseudo-relevance feedback as a mechanism for expanding short texts. Where short texts exhibit evolving concepts, topics and other characteristics, Web-based feedback systems were touted as the most ideal way of enriching the feature space of short texts. However, we note from a recent implementation of a Web-based pseudo-relevance feedback that it would only perform well under clinical situations. Further improvements to address fundamental noise in Web documents did not show significant improvements leading us to conclude that relevance feedback using Web documents directly are unsuitable for real-world conditions. In this paper, we present Eddi, which is a recent system that provides an exemplar of a typical pseudo-relevance feedback system. We first show the conditions in which Eddi will work and then discuss the situations where it would fail. We then present the variations to Eddi from our attempt to improve the robustness of Eddi's algorithm when dealing with complex Web documents. We then present the results from all variations to show the lack of robustness for pseudo-relevance feedback with Web documents.