Vortex structure and resistive transitions in high-Tc superconductors

The nature of the resistive transition for a current applied parallel to the magnetic field in high-Tc materials is investigated by numerical simulation on the three dimensional Josephson junction array model. It is shown by using finite size scaling that for samples with disorder the critical temperature Tp for the c axis resistivity corresponds to a percolation phase transition of vortex lines perpendicularly to the applied field. The value of Tp is higher than the critical temperature for j perpendicular to H, but decreases with the thickness of the sample and with anisotropy. We predict that critical behavior around Tp should reflect in experimentally accessible quantities, as the I-V curves.Comment: 8 pages + 6 figure

Technological platform for the semantic web: ontologies, natural language analysis, and e-commerce.

The goal of this project is to provide core technology for the semantic Web. Our aim is to develop an ontology-based platform for allowing users to query e-commerce applications by using natural language, performing the automatic information retrieval from web documents annotated with ontological and linguistic information. ..

Universal scaling behavior of non-equilibrium phase transitions

One of the most impressive features of continuous phase transitions is the concept of universality, that allows to group the great variety of different critical phenomena into a small number of universality classes. All systems belonging to a given universality class have the same critical exponents, and certain scaling functions become identical near the critical point. It is the aim of this work to demonstrate the usefulness of universal scaling functions for the analysis of non-equilibrium phase transitions. In order to limit the coverage of this article, we focus on a particular class of non-equilibrium critical phenomena, the so-called absorbing phase transitions. These phase transitions arise from a competition of opposing processes, usually creation and annihilation processes. The transition point separates an active phase and an absorbing phase in which the dynamics is frozen. A systematic analysis of universal scaling functions of absorbing phase transitions is presented, including static, dynamical, and finite-size scaling measurements. As a result a picture gallery of universal scaling functions is presented which allows to identify and to distinguish universality classes.Comment: review article, 160 pages, 60 figures include

Validity and reliability of the TargetScan ISSF Pistol & Rifle application for measuring shooting performance

Several technologies, with varying economic costs, are used to measure the performance of Olympic sport shooters, including electronic targets, laser systems, and mobile phone applications. Nevertheless, the International Shooting Sport Federation (ISSF) does not currently accept any mobile applications as valid measurement systems. The objective of the study was to check the validity and reliability of the TargetScan ISSF Pistol & Rifle application, an automatic mobile application for measuring the performance of shooters via image analysis. A total of 1440 shots were fired by 24 shooters (720 shots each for the air rifle and air pistol events), and the target sheets were analyzed with the application installed on an iPhone X. The official competition results and the measurements from the application were then compared. The results showed an almost perfect reliability for air pistol shots (ICC = .999) and no significant differences between the official average scores and those measured by the application. The reliability was also high for air rifle shots (ICC = .998), but the average scores registered by the application were statistically lower than the official results. We concluded that TargetScan ISSF Pistol & Rifle is a low-cost, valid, and reliable application for measuring amateur and semi-professional shooting performance which may be useful to shooters, coaches, clubs, and federations worldwid