Synchronization in two-level quantum systems

Recently, it was shown that dissipative quantum systems with three or more levels are able to synchronize to an external signal, but it was stated that it is not possible for two-level systems as they lack a stable limit cycle in the unperturbed dynamics. At the same time, several papers, demonstrate, under a different definition of what is synchronization, that the latter is possible in qubits, although in different models which also include other elements. We show how a quantum two-level system can be understood as containing a valid limit cycle as the starting point of synchronization, and that it can synchronize its dynamics to an external weak signal. This is demonstrated by analytically solving the Lindblad equation of a two-level system coupled to an environment, determining the steady state. This is a mixed state with contributions from many pure states, each of which provides a valid limit cycle. We show that this is sufficient to phase-lock the dynamics to a weak external signal, hence clarifying synchronization in two-level systems. We use the Husimi Q representation to analyze the synchronization region, defining a synchronization measure which characterizes the strength of the phase-locking. Also, we study the stability of the limit cycle and its deformation with the strength of the signal in terms of the components of the Bloch vector of the system. Finally, we generalize the model of the three-level system from in order to illustrate how the stationary fixed point of that model can be changed into a limit cycle similar to the one that we describe for the two-level system.Comment: 7 pages, 6 figure

Software para el cálculo eléctrico y mecánico de L.A.T. subterránea y aérea

Cuando se quiere diseñar una red eléctrica, uno de los problemas con los que nos encontramos, o que requieren cálculos más monótonos y tediosos, es el cálculo de las secciones de las líneas eléctricas en alta tensión, tanto los cálculos eléctricos en líneas aéreas para conductores desnudos y subterráneas con conductores aislados, como los cálculos mecánicos de conductores desnudos en las líneas aéreas, y este es precisamente el trabajo que elabora la herramienta informática realizada en este proyecto. El cálculo de las secciones no es muy complejo, sino que requiere, sobretodo en el caso de cálculos mecánicos en líneas aéreas de alta y media tensión, un número determinado de cálculos repetitivos, y que pueden ser fácilmente desarrollados por un programa de cálculo informático. Existen paquetes de software que realizan estos cálculos, con una exactitud tremenda, y con una interfaz gráfica muy fácil y austera, este software suele ser realizado por los propios fabricantes y te llevan a elegir única y exclusivamente a sus productos. El campo de aplicación de esta herramienta, es tanto para su uso por parte de los alumnos de ingenierías como para profesionales que no quieren ver las opciones de selección de conductores reducidos a los fabricados por una casa especifica, puesto que en muchas ocasiones, esa rigidez en la selección de materiales o conductores, pueden llevarnos a reducir la efectividad del proyecto. Así a su vez, este software es bastante cómodo, puesto que todo se ve en pantalla, el número de conductores sobre los que se selecciona puede ser variado, incluso modificado, mediante la introducción de los valores en una hoja de Excel, siendo esta parte idónea para proyectos que requieren de materiales no usuales o no normalizados. El software creado como objeto del presente proyecto además no requiere de ningún otro programa de pago, y por ello se convierte en un programa sin coste añadido para su disponibilidad y uso.Escuela Técnica Superior de Ingeniería IndustrialUniversidad Politécnica de Cartagen

Does Acute Beetroot Juice Supplementation Improve Neuromuscular Performance and Match Activity in Young Basketball Players? A Randomized, Placebo-Controlled Study.

Whereas beetroot juice (BJ) supplementation is shown to increase physical performance in endurance activities, its benefits in team sports has been barely studied. In this randomized placebo-controlled study, we investigated the e ects of BJ acute supplementation in improving neuromuscular performance and physical match activity in basketball. Ten young male competitive basketball players aged 15–16 years received 140 mL of BJ or placebo (PLA) on two separated days in a balanced cross-over design. Testing sessions comprised a neuromuscular test battery consisting of a countermovement jump (CMJ), isometric handgrip strength, 10-m/20-m sprint and agility T-test, followed by a 40-minute simulated basketball match. Physical match activity (distances, speeds, accelerations, and decelerations) was monitored using an inertial tracking system (Wimu ProTM) Results revealed no significant e ects of BJ on CMJ (p = 0.304, ES = 0.13), isometric handgrip strength (p = 0.777, ES = 0.06), 10-m (p = 0.820, ES = 0.10), and 20-m sprint (p = 0.540, ES = 0.13), agility T-test (p = 0.979, ES 0.01) and any physical match demands (p > 0.151, ES = 0.13–0.48). Acute moderate doses of BJ (12.8 mmol of NO3 �����) was not e ective in improving neuromuscular performance (jump height, isometric handgrip strength, sprint, and agility) or physical match requirements in young trained basketball players the day of the competition.post-print2977 K

CHAMALEON: Framework to improve Data Wrangling with Complex Data

Data transformation and schema conciliation are relevant topics in Industry due to the incorporation of data-intensive business processes in organizations. As the amount of data sources increases, the complexity of such data increases as well, leading to complex and nested data schemata. Nowadays, novel approaches are being employed in academia and Industry to assist non-expert users in transforming, integrating, and improving the quality of datasets (i.e., data wrangling). However, there is a lack of support for transforming semi-structured complex data. This article makes an state-of-the-art by identifying and analyzing the most relevant solutions that can be found in academia and Industry to transform this type of data. In addition, we propose a Domain-Specific Language (DSL) to support the transformation of complex data as a first approach to enhance data wrangling processes. We also develop a framework to implement the DSL and evaluate it in a real-world case study

Late vacuum choice and slow roll approximation in gravitational particle production during reheating

In the transition between inflation and reheating, the curvature scalar typically undergoes oscillations which have significant impact on the density of gravitationally produced particles. The commonly used adiabatic vacuum prescription for the extraction of produced particle spectra becomes a non-reliable definition of vacuum in the regimes for which this oscillatory behavior is important. In this work, we study particle production for a scalar field non-minimally coupled to gravity, taking into account the complete dynamics of spacetime during inflation and reheating. We derive an approximation for the solution to the mode equation during the slow-roll of the inflaton and analyze the importance of Ricci scalar oscillations in the resulting spectra. Additionally, we propose a prescription for the vacuum that allows to safely extrapolate the result to the present, given that the test field interacts only gravitationally. Lastly, we calculate the abundance of dark matter this mechanism yields and compare it to observations.Comment: 24 pages, 11 figure

Operational realization of quantum vacuum ambiguities

We provide a reinterpretation of the quantum vacuum ambiguities that one encounters when studying particle creation phenomena due to an external and time-dependent agent. We propose a measurement-motivated understanding: Each way of measuring the number of created particles selects a particular vacuum. This point of view gives a clear and physical meaning to the time evolution of the number of particles produced by the agent as the counts in a specific detector and, at the same time relates commonly used quantization prescriptions to particular measurement setups.Comment: 6 pages, 3 figure

DMN for Data Quality Measurement and Assessment

Data Quality assessment is aimed at evaluating the suitability of a dataset for an intended task. The extensive literature on data quality describes the various methodologies for assessing data quality by means of data profiling techniques of the whole datasets. Our investigations are aimed to provide solutions to the need of automatically assessing the level of quality of the records of a dataset, where data profiling tools do not provide an adequate level of information. As most of the times, it is easier to describe when a record has quality enough than calculating a qualitative indicator, we propose a semi-automatically business rule-guided data quality assessment methodology for every record. This involves first listing the business rules that describe the data (data requirements), then those describing how to produce measures (business rules for data quality measurements), and finally, those defining how to assess the level of data quality of a data set (business rules for data quality assessment). The main contribution of this paper is the adoption of the OMG standard DMN (Decision Model and Notation) to support the data quality requirement description and their automatic assessment by using the existing DMN engines.Ministerio de Ciencia y Tecnología RTI2018-094283-B-C33Ministerio de Ciencia y Tecnología RTI2018-094283-B-C31European Regional Development Fund SBPLY/17/180501/00029

Enabling Process Mining in Aircraft Manufactures: Extracting Event Logs and Discovering Processes from Complex Data

Process mining is employed by organizations to completely understand and improve their processes and to detect possible deviations from expected behavior. Process discovery uses event logs as input data, which describe the times of the actions that occur the traces. Currently, Internet-of-Things environments generate massive distributed and not always structured data, which brings about new complex scenarios since data must first be transformed in order to be handled by process min ing tools. This paper shows the success case of application of a solution that permits the transformation of complex semi-structured data of an assembly-aircraft process in order to create event logs that can be man aged by the process mining paradigm. A Domain-Specific Language and a prototype have been implemented to facilitate the extraction of data into the unified traces of an event log. The implementation performed has been applied within a project in the aeronautic industry, and promis ing results have been obtained of the log extraction for the discovery of processes and the resulting improvement of the assembly-aircraft process.Ministerio de Ciencia y Tecnología RTI2018-094283-B-C3

Fatigue behavior of 8 mm thick steel butt joints performed with hybrid laser arc welding

In the present research, the hybrid laser arc welding (HLAW) process has been applied to join 8 mm thick structural S355J2N steel under 1G configuration. Welding tests were performed at the Laser Welding Advanced Center available at the University of Cadiz, Spain. Different experimental welding parameters were fitted to obtain sound butt welds. The welds were subjected to different quality control tests, including visual inspection, metallographic characterization, microhardness measurements, and tensile and fatigue tests. The HLAW tests were performed at higher welding rates in 1G configuration than previously reported for 8 mm thick steels. Complete penetration was achieved in all welds, presenting suitable geometries without defects such as cracks, root humps, or porosities. Microhardness values measured at different welding zones were always below 350 HV. All welds broke at the base metal in the tensile tests. The present contribution reports novel fatigue results for these butt hybrid welds. The samples welded at the highest welding rate (2.5 m/min) were the ones providing the best fatigue response, due to the lower heat input applied under this condition

Customizing the learning of mathematics with the flipped learning model

En este trabajo se plantea un entorno de aprendizaje autodirigido basado en el modelo pedagógico Flipped learning y apoyado en la tecnología, orientado a una personalización de la enseñanza de las matemáticas. Se pretende determinar si la experiencia realizada incide en el rendimiento académico, la satisfacción del alumnado, las emociones experimentadas y si se existen diferencias en función del género. Se ha utilizado una metodología cuantitativa con un diseño preexperimental pretest y postest. En la experiencia han participado 62 estudiantes que cursan la asignatura de Matemáticas orientadas a las enseñanzas académicas de 3º y 4º de Educación Secundaria Obligatoria. Los resultados muestran una mejora en el rendimiento académico, y un nivel de satisfacción elevado con la experiencia de aprendizaje. El modelo propuesto se ha adaptado a la diversidad del aula y superado las diferencias entre hombres y mujeres en cuanto a actitud y emociones con respecto a las matemáticas.This work outlines a self-directed learning environment which is based on the Flipped learning pedagogical model and supported by technology, aimed at personalising the teaching of mathematics. The target of this study is to determine how this tested-model impacts the academic performance, satisfaction levels and the emotional progress on the students; these are also reviewed based on gender. A quantitative methodology, based on a pre-experimental design that involves both, a pre-test and a post-test, has been used. The experience involved 62 students taking the subject of Mathematics oriented to the academic teaching of 3rd and 4th year of Compulsory Secondary Education. The collected data reflects an improvement on academic performance and high levels of satisfaction from the students. The proposed model has proved adaptable towards the student’ diversity and overcame the potential differences between men and women regarding their attitude and emotions toward the subject of Mathematics