Search results for "Normalization"
showing 10 items of 632 documents
Ordering and demixing transitions in multicomponent Widom-Rowlinson models.
1995
We use Monte Carlo techniques and analytical methods to study the phase diagram of multicomponent Widom-Rowlinson models on a square lattice: there are M species all with the same fugacity z and a nearest neighbor hard core exclusion between unlike particles. Simulations show that for M between two and six there is a direct transition from the gas phase at z < z_d (M) to a demixed phase consisting mostly of one species at z > z_d (M) while for M \geq 7 there is an intermediate ``crystal phase'' for z lying between z_c(M) and z_d(M). In this phase, which is driven by entropy, particles, independent of species, preferentially occupy one of the sublattices, i.e. spatial symmetry but not …
Intersectionalities, dis/abilities and subjectification in deaf LGBT people: An exploratory study in Sicily
2016
The article discusses the multiple discrimination, normalization and stigmatization experienced by deaf LGBT youth in Sicily, Italy, on the basis of a study of their everyday life (specifically school years and peer interactions). So far in Italy, very little attention has been paid to multiple discrimination and, specifically, to homophobic violence towards disabled individuals. It is, therefore, impossible to consider any valid sampling of the desired population and very few reports have been produced. The authors, a sociologist and a psychologist, carry out an analysis of the results obtained from interviews with 15 LGBT individuals recruited through social networks, thematic chats, and …
In praise of artifice reloaded: Caution with natural image databases in modeling vision
2019
Subjective image quality databases are a major source of raw data on how the visual system works in naturalistic environments. These databases describe the sensitivity of many observers to a wide range of distortions of different nature and intensity seen on top of a variety of natural images. Data of this kind seems to open a number of possibilities for the vision scientist to check the models in realistic scenarios. However, while these natural databases are great benchmarks for models developed in some other way (e.g., by using the well-controlled artificial stimuli of traditional psychophysics), they should be carefully used when trying to fit vision models. Given the high dimensionalit…
What is Experience? : Foucauldian Perspectives
2019
Michel Foucault’s (1926–1984) thought is widely used in the humanities and social sciences for investigating experiences of madness, illness, marginalization and social conflicts. However, the meaning of the word “experience” is not always clearly defined, and the French word expérience has a whole variety of meanings. In this article I explicate Foucault’s most relevant concepts of experience and their theoretical functions. He refers to experience throughout his career, especially in his early texts on existential psychiatry from the 1950s and 1960s and in his late work from the 1980s. Texts such as Mental Illness and Psychology and Dire vrai sur soi-même have received less attention than…
The Gauge Glass Transition
1993
Results of Monte Carlo simulations in three and four spatial dimensions of a simple model that seems to have the necessary ingredients for disordered type-II superconductor behavior in an external magnetic field are reported. The data suggest that in d = 3 dimensions there is a finite temperature phase transition at T ≈ 0.45 into a truly superconducting vortex glass phase with infinite d.c. conductivity The (effective) correlation length exponent v and the dynamic critical exponent z at this transition are in good agreement with experiments. In d = 4 dimensions the gauge glass transition is located at T ≈ 0.95. It is concluded that the lack of time reversal symmetry in the model places it i…
Surface emissivity retrieval from Digital Airborne Imaging Spectrometer data
2002
[1] A study has been carried out on the most recent algorithms for the estimation of land surface emissivity (e) using high-resolution data (Digital Airborne Imaging Spectrometer, DAIS) over the Rhine Valley (France) and Castilla La Mancha (Spain). Three published methods have been applied for extracting absolute spectral emissivity information from images recorded during the DAISEX experiment in 1999. They are NDVI Thresholds Method (NDVITHM), Normalized Emissivity Method (NEM) and Temperature/Emissivity Separation (TES). These lather two methods were originally designed to work over geological surfaces. Five methods have been used for extracting relative spectral emissivity. They are temp…
Continuous Phase Transitions at Surfaces of CuAu Alloy Models — A Monte Carlo Study of Surface Induced Order and Disorder
1996
The influence of surface on phase transitions has found significant attention in recent years, and a number of excellent reviews exists. [1, 2, 3] A variety of complex phenomena occur which are also related to the physics of adsorption and wetting. The scenario of wetting requires three distinct phases, for instance the vacuum, the bulk phase and a third phase intervening in between at equilibrium. In case of surface induced disorder (SID, a film of disordered layers at the surface “wets” the bulk phase as the temperature approaches the bulk transition temperature T c,b. The transition at the surface may be continuous (standard critical wetting phenomena), and, as theoretically investigated…
Universal critical behavior of curvature-dependent interfacial tension.
2011
From the analysis of Monte Carlo simulations of a binary Lennard-Jones mixture in the coexistence region, we provide evidence that the curvature dependence of the interfacial tension can be described by a simple theoretical function σ(R)ξ(2)=C(1)/[1+C(2)(ξ/R)(2)], where ξ is the correlation length and R is the droplet radius. The universal constants C(1) and C(2) are estimated. In the model, a Tolman length is strictly absent, but, since its critical behavior is believed to be much weaker than ξ, we argue that it only provides a correction to scaling and does not affect the leading critical behavior, which should be described by the above function for any system in the Ising universality cl…
Phase separation of symmetric polymer mixtures in a common good solvent in the semidilute concentration regime
1994
Monte Carlo simulations of lattice models of binary (AB) symmetric polymer mixtures (chain lengthsN A=N B=N) in a common good solvent are carried out and the phase diagrams and critical properties of the unmixing transitions are estimated and interpreted in terms of recent theories. Polymers are modeled by self-avoiding walks of lengthN=16, 32 and 64 on the simple cubic lattice. Data for vacancy concentrations of φV=0.6, 0.8 and 0.85 are analyzed. It is shown that forN=16, φV=0.85 no phase separation occurs, down to the lowest temperature, while forN=32, φV=0.85 still phase separation occurs but no longer is complete. Our results are compatible with a scaling theory based on a “renormalizat…
Thermodynamic formalism and linear response theory for non-equilibrium steady states
2016
We study the linear response in systems driven away from thermal equilibrium into a nonequilibrium steady state with nonvanishing entropy production rate. A simple derivation of a general response formula is presented under the condition that the generating function describes a transformation that (to lowest order) preserves normalization and thus describes a physical stochastic process. For Markov processes we explicitly construct the conjugate quantities and discuss their relation with known response formulas. Emphasis is put on the formal analogy with thermodynamic potentials and some consequences are discussed.