Assessing the gaming experience using puppetry

In this paper we address the question: What factors of game experience are measured and have to be measured? by proposing a concept called Puppetry to assess the experience while playing videogames. Puppetry was obtained using qualitative methods on the experiences of players. The main characteristic of Puppetry is that it looks at the common elements of videogames that allow the user to build the experience

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

Environmental effects on galaxy evolution. II: quantifying the tidal features in NIR-images of the cluster Abell 85

This work is part of a series of papers devoted to investigate the evolution of cluster galaxies during their infall. In the present article we imaged in NIR a selected sample of galaxies through- out the massive cluster Abell 85 (z = 0.055). We obtained (JHK) photometry for 68 objects, reaching 1 mag/arcsec^2 deeper than 2MASS. We use these images to unveil asymmetries in the outskirts of a sample of bright galaxies and develop a new asymmetry index, alpha_An, which allows to quantify the degree of disruption by the relative area occupied by the tidal features on the plane of the sky. We measure the asymmetries for a subsample of 41 large area objects finding clear asymmetries in ten galaxies, most of them being in groups and pairs projected at different clustercentric distances, some of them located beyond R500 . Combining information on the Hi-gas content of blue galaxies and the distribution of sub-structures across Abell 85, with the present NIR asymmetry analysis, we obtain a very powerful tool to confirm that tidal mechanisms are indeed present and are currently affecting a fraction of galaxies in Abell 85. However, when comparing our deep NIR images with UV-blue images of two very disrupted (jellyfish) galaxies in this cluster, we discard the presence of tidal 1 interactions down to our detection limit. Our results suggest that ram-pressure stripping is at the origin of such spectacular disruptions. We conclude that across a complex cluster like Abell 85, environment mechanisms, both gravitational and hydrodynamical, are playing an active role in driving galaxy evolution.Comment: 30 pages, 13 figures, Accepted for Publication in A

Bounds on the mass and abundance of dark compact objects and black holes in dwarf spheroidal galaxy halos

We establish new dynamical constraints on the mass and abundance of compact objects in the halo of dwarf spheroidal galaxies. In order to preserve kinematically cold the second peak of the Ursa Minor dwarf spheroidal (UMi dSph) against gravitational scattering, we place upper limits on the density of compact objects as a function of their assumed mass. The mass of the dark matter constituents cannot be larger than 1000 solar masses at a halo density in UMi's core of 0.35 solar masses/pc^3. This constraint rules out a scenario in which dark halo cores are formed by two-body relaxation processes. Our bounds on the fraction of dark matter in compact objects with masses >3000 solar masses improve those based on dynamical arguments in the Galactic halo. In particular, objects with masses $\sim 10^{5}$ solar masses can comprise no more than a halo mass fraction $\sim 0.01$. Better determinations of the velocity dispersion of old overdense regions in dSphs may result in more stringent constraints on the mass of halo objects. For illustration, if the preliminary value of 0.5 km/s for the secondary peak of UMi is confirmed, compact objects with masses above $\sim 100$ solar masses could be excluded from comprising all its dark matter halo.Comment: 6 pages, 2 figures, accepted for publication in ApJ Letter

Hemodynamics in the thoracic aorta using OpenFOAM: 4D PCMRI versus CFD

The aim of this work is the study of fluid dynamics models using the CFD software OpenFOAM, an open source software allowing meshing, manipulation, simulation and post-processing of many problems involving fluid mechanics. The work consists of a study with OpenFOAM of a real engineering problem, namely to analyze hemodynamics in the thoracic aorta in collaboration with CIMNE (Centre Internacional de Metodes Numerics a l'Enginyeria) and LABSON-UPC (Laboratorio de Sistemas Oleohidricos y Neumcos). Speci cally, the study aims to compute the shear stress that blood causes to aorta walls

Studying the nuclear mass composition of Ultra-High Energy Cosmic Rays with the Pierre Auger Observatory

The Fluorescence Detector of the Pierre Auger Observatory measures the atmospheric depth, $X_{max}$, where the longitudinal profile of the high energy air showers reaches its maximum. This is sensitive to the nuclear mass composition of the cosmic rays. Due to its hybrid design, the Pierre Auger Observatory also provides independent experimental observables obtained from the Surface Detector for the study of the nuclear mass composition. We present $X_{max}$-distributions and an update of the average and RMS values in different energy bins and compare them to the predictions for different nuclear masses of the primary particles and hadronic interaction models. We also present the results of the composition-sensitive parameters derived from the ground level component.Comment: Proceedings of the 12th International Conference on Topics in Astroparticle and Underground Physics, TAUP 2011, Munich, German

Diffuse Ionized Gas in the Dwarf Irregular Galaxy DDO 53

The spectral characteristics throughout the dwarf irregular galaxy DDO 53 are studied. The results are very similar to those for other irregular galaxies: high excitation and low values of the [SII]/Halpha ratio. The most likely ionization source is photon leakage from the classical HII regions, without any other source, although the interstellar medium of the galaxy is quite perturbed. Moreover, the physical conditions throughout the galaxy do not change very much because both the photon leakage percentage and the ionization temperature are very similar. In addition, the determined metal content for two HII regions indicates that DDO 53 is a low-metallicity galaxy.Comment: 32 pages, 9 figures, 7 tables. AJ, in pres

Photoactivation of the cytotoxic properties of platinum(II) complexes through ligand photoswitching

The development of photoactivatable metal complexes with potential anticancer properties is a topical area of current investigation. Photoactivated chemotherapy using coordination compounds is typically based on photochemical processes occurring at the metal center. In the present study, an innovative approach is applied that takes advantage of the remarkable photochemical properties of diarylethenes. Following a proof-of-concept study with two complexes, namely, C1 and C2, a series of additional platinum(II) complexes from dithienylcyclopentene-based ligands was designed and prepared. Like C1 and C2, these new coordination compounds exhibit two thermally stable, interconvertible photoisomers that display distinct properties. The photochemical behavior of ligands L3-L7 has been analyzed by 1H NMR and UV-vis spectroscopies. Subsequently, the corresponding platinum(II) complexes C3-C7 were synthesized and fully characterized, including by single-crystal X-ray diffraction for some of them. Next, the interaction of each photoisomer (i.e., containing the open or closed ligand) of the metal complexes with DNA was examined thoroughly using various techniques, revealing their distinct DNA-binding modes and affinities, as observed for the earlier compounds C1 and C2. The antiproliferative activity of the two forms of the complexes was then assessed with five cancer cell lines and compared with that of C1 and C2, which supported the use of such diarylethene-based systems for the generation of a new class of potential photochemotherapeutic metallodrugs