Search results for "COMPRESSION"

Subjective image fidelity metric based on bit allocation of the human visual system in the DCT domain

1997

Until now, subjective image distortion measures have partially used diverse empirical facts concerning human perception: non-linear perception of luminance, masking of the impairments by a highly textured surround, linear filtering by the threshold contrast frequency response of the visual system, and non-linear post-filtering amplitude corrections in the frequency domain. In this work, we develop a frequency and contrast dependent metric in the DCT domain using a fully non-linear and suprathreshold contrast perception model: the Information Allocation Function (IAF) of the visual system. It is derived from experimental data about frequency and contrast incremental thresholds and it is cons…

Impact of cyclic mechanical stress on the electrical contact resistance between gas diffusion layer and bipolar plates in Polymer Electrolyte Membran…

2018

WHEC 2018, 22nd edition of the WORLD HYDROGEN ENERGY CONFERENCE, Rio de Janeiro, BRESIL, 17-/06/2018 - 22/06/2018; and collisions) and the mechanical clamping stress applied during the stack assembly. The internal stresses come from the shrinking and the swelling of the membrane caused by water content and the difference between the thermal expansion coefficients of the cell components. These mechanical stresses have an impact on the global fuel cell's performance and one of the most sensitive cell's components to this pressure is the Gas Diffusion Layer (GDL). This layer, assembled with the membrane electrode assembly, provides the reactant gases, evacuates the produced heat and …

The efficiency of gel permeation chromatography

2007

The resolution power of gel permeation chromatography (GPC) columns and their combinations is tested as a function of the pore sizes of the gels and as a function of the elution velocity. The efficiency of GPC is characterized by the ratio UG/UT, where UG is the experimental, and UT the theoretical, inhomogeneity. The latter quantity is obtained from absolute measurements of Mw, and Mn. The ratio passes through a minimum for a series of columns with increasing pore sizes. The minimum occurs at that column or column set which is best suited to resolving a given polymer. UG/UT for any column decreases with decreasing elution velocity. At a certain velocity UG/UT becomes 1. This velocity is us…

2D motif basis applied to the classification of digital images

2016

The classification of raw data often involves the problem of selecting the appropriate set of features to represent the input data. Different types of features can be extracted from the input dataset, but only some of them are actually relevant for the classification process. Since relevant features are often unknown in real-world problems, many candidate features are usually introduced. This degrades both the speed and the predictive accuracy of the classifier due to the presence of redundancy in the set of candidate features. Recently, a special class of bidimensional motifs, i.e. 2D motif basis has been introduced in the literature. 2D motif basis showed to be powerful in capturing the r…

Magnetic Monopole Search with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions Interpreted in Photon-Fusion and Drell-Yan Production

2019

MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb$^{-1}$ of 13 TeV proton-proton collisions at the LHC…

Differential diagnosis problems in a patient with dysphonia and chronic lymphocytic leukemia

2014

SUMMARY Dysphonia is frequently an expression of laryngitis, especially when it comes in the evolution of an immunosuppressed patient, as happens in chronic lymphoproliferation. But other causes of dysphonia should also not be forgotten, including the possibility of new malignancies, especially due to the fact that these patients have genomic instability that predisposes to appearance of a second or even a third cancer. We present the case of a patient who developed dysphonia during chronic lymphocytic leukemia evolution. Its etiology was a mediastinal compression through lymph nodes, not linked to leukemia, but produced by metastases of a bronchopulmonary cancer, appeared recently. Dysphon…

Equilibrium and disequilibrium degassing of a phonolitic melt (Vesuvius AD 79 “white pumice”) simulated by decompression experiments

2007

Abstract Equilibrium and disequilibrium degassing of a volatile phase from a magma of K-phonolitic composition was investigated to assess its behavior upon ascent. Decompression experiments were conducted in Ar-pressurized externally heated pressure vessels at superliquidus temperature (1050 °C), in the pressure range 10–200 MPa using pure water as fluid phase. All experiments were equilibrated at 200 MPa and then decompressed to lower pressures with rates varying from 0.0028 to 4.8 MPa/s. Isobaric saturation experiments were performed at the same temperature and at 900–950 °C to determine the equilibrium water solubility in the pressure range 30–250 MPa. The glasses obtained from decompres…

P2‐310: MIDLIFE SELF‐RATED HEALTH AND FITNESS IN RELATION TO WHITE MATTER LESIONS AND GREY MATTER VOLUME 20 YEARS LATER

2014

Midlife self-rated health and fitness in relation to white matter lesions and grey matter volume 20 years later

2016

Summary Background Healthy life expectancy (HALE) and disability-adjusted life-years (DALYs) provide summary measures of health across geographies and time that can inform assessments of epidemiological patterns and health system performance, help to prioritise investments in research and development, and monitor progress toward the Sustainable Development Goals (SDGs). We aimed to provide updated HALE and DALYs for geographies worldwide and evaluate how disease burden changes with development. Methods We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive …

The Inverse Seesaw Family: Dirac And Majorana

2021

After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking "$\mu$-terms". These models can be tested both in colliders and with the observation of lepton flavour violating processes.