Comparison of Balancing Techniques for Multimedia IR over Imbalanced Datasets

A promising method to improve the performance of information retrieval systems is to approach retrieval tasks as a supervised classification problem. Previous user interactions, e.g. gathered from a thorough log file analysis, can be used to train classifiers which aim to inference relevance of retrieved documents based on user interactions. A problem in this approach is, however, the large imbalance ratio between relevant and non-relevant documents in the collection. In standard test collection as used in academic evaluation frameworks such as TREC, non-relevant documents outnumber relevant documents by far. In this work, we address this imbalance problem in the multimedia domain. We focus on the logs of two multimedia user studies which are highly imbalanced. We compare a naiinodotve solution of randomly deleting documents belonging to the majority class with various balancing algorithms coming from different fields: data classification and text classification. Our experiments indicate that all algorithms improve the classification performance of just deleting at random from the dominant class

A very high resolution X- and Ku-band field study of a barley crop in support of the SWINTOL Project

SAR Wave INteraction for Natural Targets Over Land (SWINTOL) is a project funded by the European Space Agency. The study’s goal is to better understand the interaction of high frequency radar (> X-band) with vegetation and soils, in order to drive the development of a high-frequency electromagnetic model to simulate SAR imagery at high resolution (< 1 m). Existing models work well at C and X band frequencies, but do not work properly at higher frequencies. Cranfield University’s role in this project was to provide the field data necessary for model validation and development. Radar imagery was taken of a barley crop over an entire growing season. The portable outdoor GB-SAR system used the tomographic profiling (TP) technique to capture polarimetric imagery of the crop. TP is a scheme that provides detailed maps of the vertical backscatter pattern through a crop canopy, along a narrow transect directly beneath the radar platform. Fully-polarimetric imagery was obtained across overlapping 6.5 GHz bandwidths over the X- and Ku-band frequency range 8-20 GHz. This gave the opportunity to see the detailed scattering behaviour within the crop at the plant component level, from emergence of the crop through to harvesting. In combination with the imagery, full bio-geophysical characterisation of the crop and soil was made on each measurement date. Surface roughness characterisation of the soil was captured using a 3D optical stereoscopic system. This work details the measurements made, and provides a comparative assessment of the results in terms of understanding the backscatter in relation to biophysical and radar parameters

Effects of nonlinear dispersion on squeezed states in two-photon devices

7 págs.; 4 figs.; 1 apémdiceThe deleterious effects of nonlinear dispersion on squeezed light in two-photon devices when absorption losses are included have been analyzed making use of the variables called two-mode quadrature-phase amplitudes. The uncertainties in the quadrature amplitudes have been computed from a generalized Fokker-Planck equation. The dependence of squeezing on the nonlinear coupling, the modulation (including the case of high modulations), the pumping phase (where nonlinear dispersion causes an intensity-dependent shift in the minimum squeezing), and the absorption losses have been studied. © 1989 The American Physical Society.Peer Reviewe

Low-noise properties of squeezed light in transmission chains formed from nonlinear alternating attenuators and amplifiers

4 págs.; 4 figs.An idealized model of an optical communication link in which identical sections of nonlinear attenuating fiber alternate with identical amplifiers is considered. Signal-to-noise ratios of chains of these elements for input squeezed and coherent light have been numerically evaluated. It is found that input squeezed light and nonlinear attenuators improve the signal-to-noise ratios with respect to coherent inputs and linear chains. In the case of three-photon attenuators, the noise and signal-to-noise ratio remain practically constant from certain elements of the chain. Moreover, the influence of the attenuation coefficient and the input mean photon number on the signal-to-noise ratios was considered, as well as chains with nonlinear amplifiers and chains in which the amplifier gain does not exactly compensate for the fiber attenuation. © 1988 The American Physical Society.Peer Reviewe

Extended sources in the XMM-Newton slew survey

The low background, good spatial resolution and great sensitivity of the EPIC-pn camera on XMM-Newton give useful limits for the detection of extended sources even during the short exposures made during slewing maneouvers. In this paper we attempt to illustrate the potential of the XMM-Newton slew survey as a tool for analysing flux-limited samples of clusters of galaxies and other sources of spatially extended X-ray emission.Comment: 2 pages, 4 figures, to appear in the proceedings of "The X-ray Universe 2005", San Lorenzo de El Escorial (Spain), 26-30 September 200

The XMM-Newton Slew Survey: towards the XMMSL1 catalogue

The XMM-Newton satellite is the most sensitive X-ray observatory flown to date due to the great collecting area of its mirrors coupled with the high quantum efficiency of the EPIC detectors. It performs slewing manoeuvers between observation targets tracking almost circular orbits through the ecliptic poles due to the Sun constraint. Slews are made with the EPIC cameras open and the other instruments closed, operating with the observing mode set to the one of the previous pointed observation and the medium filter in place. Slew observations from the EPIC-pn camera in FF, eFF and LW modes provide data, resulting in a maximum of 15 seconds of on-source time. These data can be used to give a uniform survey of the X-ray sky, at great sensitivity in the hard band compared with other X-ray all-sky surveys.Comment: 2 pages, 2 figures, to appear in the proceedings of "The X-ray Universe 2005", San Lorenzo de El Escorial (Spain), 26-30 September 200

The Boomerang Effect: How Nurses' Regulation of Patients' Affect Associates With Their Own Emotional Exhaustion and Affective Experiences

Recent research has shown that the intentional regulation of others’ affect has effects not only on the target (e.g., a patient) of the regulation, but also on the agent (e.g., a nurse). In particular, the use of intentional interpersonal affect regulation strategies has been found to predict employees’ emotional exhaustion (EEx). Use of affect-worsening strategies is associated with an increase in EEx, whereas the effect of using affect-improving strategies is less clear. Another relevant consequence of interpersonal affect regulation is its effect on affective experiences, which is one of the main determinants of job attitudes. This study tests the relationships between the interpersonal affect regulation strategies that nurses use to regulate their patients’ affect and the nurses’ EEx and affective experiences. A longitudinal 2-wave field study was conducted in sample of nurses. Participants completed a questionnaire on 2 different occasions, 2 months apart (Time 1 [T1], Time 2 [T2]). Of the 141 participants at T1, 103 also completed the survey at T2. Longitudinal hierarchical regression analyses showed that using affect-worsening strategies was a significant predictor of nurse’s EEx, whereas using affect-improving strategies did not significantly predict their EEx. For affective experiences, use of affect-worsening strategies was related to nurses experiencing low-activation negative affect (e.g., feeling depressed); whereas affect-improving strategies was related to them experiencing low-activation positive affect (e.g., feeling calm). Results support the view that intentional regulation of patients’ affect needs to be considered not only in relation to the patients’ perception of service quality but also from the perspective of nurses’ well-being

Electrochemical behavior of lanthanum and yttrium ions in two molten chlorides with different oxoacidic properties: The eutectic LiCl-KCl and the equimolar mixture CaCl2-NaCl

The electrochemical behavior of LaCl3 and YCl3 was studied in two molten chloride mixtures with different oxoacidic properties, the eutectic LiCl-KCl and the equimolar CaCl2-NaCl melt at different temperatures. The stable oxidation states of both elements have been found to be (III) and (0) in both melts, and it was found that both La(III) and Y(III) cations were less solvated by the chloride ions in the calcium-based melt, which was explained by the stability of CaCl4 2- ions in that melt. Transient electrochemical techniques, such as cyclic voltammetry, chronopotentiometry and chronoamperometry were used in order to study the reaction mechanism and the transport parameters of electro active species at a tungsten electrode. The results showed that in the eutectic LiCl-KCl, the electro crystallization of lanthanum and yttrium seems to be the controlling electrochemical step while in CaCl2-NaCl this phenomenon has not been observed. That was explained in terms of the differences in the physicochemical properties of the systems, especially interfacial tensions. In the eutectic LiCl-KCl chronoamperometric studies indicated instantaneous and three dimensional nucleation and crystal growth of lanthanum and yttrium whatever the applied over potential of the rare earth metal is, whereas in the equimolar mixture CaCl2-NaCl, the corresponding electrochemical exchanges were found to be quasi-reversible, and the values of the kinetic parameters, K0 and α,were obtained for both reactions. Mass transport towards the electrode is a simple diffusion process, and the diffusion coefficients have been calculated. The validity of the Arrhenius law was also verified by plotting the variation of the logarithm of the diffusion coefficient versus 1/T

Diferentation of ecotypes in spanish water dog

In this paper we have developed a study of the Spanish Water dog (P.A.E.) breed attending to their morphostructure and coat colours. We have concluded the existence of three different ecotypes inside this breed. The mountain variety present a morpho-structure typical of the shepherd dogs, while the northern and marshes varieties present swimming qualities. The study of the coat colour has shown a correspondence between the clear coats and the northern variety, and the black and brown coats with the mountain and marshes varieties respectively.En el presente trabajo desarrollamos un estudio en el Perro de Agua Español (P.A.E.) atendiendo a su morfoestructura y al color de la capa. Se concluye con la existencia de tres ecotipos diferenciados dentro de la raza. La variedad serrana presenta una morfoestructura más apta para las funciones de perro de ganado en la conducción de los rebaños mientras que la variedad norteña y marismeña presentan unas cualidades más idóneas en tareas de natación. En el estudio del color de la capa observamos que las frecuencias más altas de las capas claras corresponden a la variedad norteña, mientras que las capas negras y castañas son propias de la variedad serrana y marismeña respectivamente