Medida de la sección eficaz de producción de tZq en colisiones pp a √8 =13TeV en CMS

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física teórica. Fecha de Lectura: 13-06-2022This document presents a measurement of the production cross section of a single top quark in association with a Z boson (and an additional quark), a rare standard model process which is also an irreducible background to many important searches at the Large Hadron Collider (LHC). The process is studied using events with three leptons (electrons or muons) in the nal state for an integrated luminosity of 35:9 fb1 recorded by the Compact Muon Solenoid (CMS) detector at the LHC using proton-proton collisions at a centre-of-mass energy of 13 TeV. In these accelerator conditions, the reference next-to-leading-order (NLO) cross section for tZq ! Wb`+ q (considering only leptonic decays of the Z boson to electrons, muons or tau leptons) is 94:2+1:9 1:8 (scale) 2:5 (PDF) fb, which includes lepton pairs from o -shell Z bosons with invariant mass m`+ > 30 GeV. Previous analyses had been conducted at the LHC at 8 TeV but it was not until 2017, when the analysis described in this document was performed, that the rst evidence for this process was presented, also announced by the ATLAS collaboration in the same year. The evidence of this process along with a measurement of its cross section compatible with the prediction, represents an important test of the standard model. The nal state of the process is identical to avour-changing neutral current tZq production. Flavour-changing neutral currents (FCNC) are a phenomenon which is highly suppressed in the standard model, predicted to occur at rates that are not accessible at the current accelerator conditions. In fact, analyses looking for FCNC tZq signatures are conducted in parallel to tZq standard model searches by the experimental community. The cross section measurement presented is sensitive to the contribution from FCNC tZq production, were there incompatibilities with the theoretical standard model prediction. For this analysis, a multivariate classi cation approach is used to achieve a powerful discrimination between signal-like events and other standard model processes (background). The cross section is extracted from a maximum likelihood t performed simultaneously on three statistically independent regions for the four different leptonic channels (three electrons, three muons, two electrons and one muon, and one electron and two muons). The rst region is de ned to be populated mostly by signal events while the other two control regions are de ned so that they contain mostly events from the main background processes. The measurement yields a cross section value (pp ! tZq ! Wb`+`q) = 123+33 31 (stat) +29 23 (syst) fb, calculated so that it contains the contribution from tau leptons too. The observed (expected) signi cance is reported to be 3.7 (3.1) standard deviation

Improving university argumentative writing through online training

Writing an argumentation about a controversial issue from contradictory sources is a challenging task. It involves understanding, managing, and generating arguments and counterarguments from different sources to support a final position, conveyed in a formal structure. Despite its difficulty, argumentative writing is not often taught in higher education in Spain. Furthermore, online interventions regarding this type of task are scarce. For this reason, we designed and evaluated virtual training aimed at writing integrative and wellstructured arguments in a distance learning university. Sixty-eight undergraduates participated in this pre-post with a control group design. The training included explicit instruction through video lectures and practice exercises with immediate feedback using open online resources (e.g., Moodle). The results show that after the instruction the participants' written products improved both in their structure, the number of arguments for the against-position, and the degree of integration of the two perspectives. However, those products that presented medium or maximum integration were still limited. These results illustrate how online instruction of argumentative writing can be implemented in higher education with positive results. However, students still need more support to expand their skills for generating integrative synthesis. Considering these results, we propose further improvements in the designed training. : Earli | This article is published under Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 Unported license

Analysis of the evolution of the Spanish labour market through unsupervised learning

Unemployment in Spain is one of the biggest concerns of its inhabitants. Its unemployment rate is the second highest in the European Union, and in the second quarter of 2018 there is a 15.2% unemployment rate, some 3.4 million unemployed. Construction is one of the activity sectors that have suffered the most from the economic crisis. In addition, the economic crisis affected in different ways to the labour market in terms of occupation level or location. The aim of this paper is to discover how the labour market is organised taking into account the jobs that workers get during two periods: 2011-2013, which corresponds to the economic crisis period, and 2014-2016, which was a period of economic recovery. The data used are official records of the Spanish administration corresponding to 1.9 and 2.4 million job placements, respectively. The labour market was analysed by applying unsupervised machine learning techniques to obtain a clear and structured information on the employment generation process and the underlying labour mobility. We have applied two clustering methods with two different technologies, and the results indicate that there were some movements in the Spanish labour market which have changed the physiognomy of some of the jobs. The analysis reveals the changes in the labour market: the crisis forces greater geographical mobility and favours the subsequent emergence of new job sources. Nevertheless, there still exist some clusters that remain stable despite the crisis. We may conclude that we have achieved a characterisation of some important groups of workers in Spain. The methodology used, being supported by Big Data techniques, would serve to analyse any alternative job market.Ministerio de Economía y Competitividad TIN2014-55894-C2-R y TIN2017-88209-C2-2-R, CO2017-8678

Sensorial Integration in early childhood Education students and students with Special Educational Needs

Jean Ayres definió la integración sensorial como el proceso que organiza las entradas sensoriales para que el cerebro produzca una respuesta corporal útil. Esta terapia resulta eficaz cuando el cerebro utiliza aquellas funciones que puede aprovechar con mayor facilidad. A la hora de estructurar las dietas sensoriales o actividades se debe de tener en cuenta las características y necesidades del alumno, diferenciándolas según los cinco sentidos: olfato, vista, tacto, oído y gusto, así como, el sentido perceptivo y el vestibular. Estas sesiones han de resultar un elemento lúdico dentro de un ambiente organizado y seguro para ello.Jane Ayres defined the sensorial integration as the process which organize the sensorial entries for the brain to produce an useful corporal answer. This therapy becomes efficient when the brain employs those functions more easily usable. When structuring the sensorial diets or activities, the characteristics and necessities of the student must be taken into account. These must be differentiated by the five senses: smell, sight, touch, hearing and taste, as well as the perceptive sense and the vestibular. These sessions must result a ludic element in an organized environment and secure for that purpose

External clustering validity index based on chi-squared statistical test

Clustering is one of the most commonly used techniques in data mining. Its main goal is to group objects into clusters so that each group contains objects that are more similar to each other than to objects in other clusters. The evaluation of a clustering solution is a task carried out through the application of validity indices. These indices measure the quality of the solution and can be classified as either internal that calculate the quality of the solution through the data of the clusters, or as external indices that measure the quality by means of external information such as the class. Generally, indices from the literature determine their optimal result through graphical representation, whose results could be imprecisely interpreted. The aim of this paper is to present a new external validity index based on the chi-squared statistical test named Chi Index, which presents accurate results that require no further interpretation. Chi Index was analyzed using the clustering results of 3 clustering methods in 47 public datasets. Results indicate a better hit rate and a lower percentage of error against 15 external validity indices from the literature.Ministerio de Economía y Competitividad TIN2014-55894-C2-RMinisterio de Economía y Competitividad TIN2017-88209-C2-2-

An approach to validity indices for clustering techniques in Big Data

Clustering analysis is one of the most used Machine Learning techniques to discover groups among data objects. Some clustering methods require the number of clus ters into which the data is going to be partitioned. There exist several cluster validity indices that help us to approximate the optimal number of clusters of the dataset. However, such indices are not suitable to deal with Big Data due to its size limitation and runtime costs. This paper presents two cluster ing validity indices that handle large amount of data in low computational time. Our indices are based on redefinitions of traditional indices by simplifying the intra-cluster distance calculation. Two types of tests have been carried out over 28 synthetic datasets to analyze the performance of the proposed indices. First, we test the indices with small and medium size datasets to verify that our indices have a similar effectiveness to the traditional ones. Subsequently, tests on datasets of up to 11 million records and 20 features have been executed to check their efficiency. The results show that both indices can handle Big Data in a very low computational time with an effectiveness similar to the traditional indices using Apache Spark framework.Ministerio de Economía y Competitividad TIN2014-55894-C2-1-

An Approach to Silhouette and Dunn Clustering Indices Applied to Big Data in Spark

K-Means and Bisecting K-Means clustering algorithms need the optimal number into which the dataset may be divided. Spark implementations of these algorithms include a method that is used to calculate this number. Unfortunately, this measurement presents a lack of precision because it only takes into account a sum of intra-cluster distances misleading the results. Moreover, this measurement has not been well-contrasted in previous researches about clustering indices. Therefore, we introduce a new Spark implementation of Silhouette and Dunn indices. These clustering indices have been tested in previous works. The results obtained show the potential of Silhouette and Dunn to deal with Big Data.Ministerio de Economía y Competitividad TIN2014-55894-C2-1-

Looking for students' enthusiasm: flipped classroom

The “flipped classroom” is a pedagogical model that consists of putting certain learning processes outside the classroom so that the teacher can devote more class time to students’ acquisition of practical skills, for example. In this way, the teacher is not limited to the transmission of course content, but in addition assumes the role of a mediator in the cognitive process, allowing students to actively construct their own knowledge. In this role, the teacher’s main task is to encourage students to become independent learners. This paper describes the implementation and initial results of the application of the flipped classroom in higher education. This study is part of a larger research project to improve our students’ motivation through the use of the flipped learning. The sample consisted of about 3000 students taking 17 different subjects, in Management and Administration Business, Finance and Accounting, Marketing and Market Research, and Chemistry, at the University of Málaga, and in Accounting and Administration, Business Communication and Marketing at the Polytechnic of Porto. According to our results, students’ motivation and class attendance increased with the application of this model; a comparison of the final exam results from two years with traditional classes and from two years with flipped learning shows that the proportion of students failing the exam decreased, which confirms that the use of this pedagogic model improves student learning.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This project is financed by Educational Innovation Projects 2017-2019 from Malaga University

Gamificacion in education and active methodologies at Higher education

In recent years, there has been an increasing interest in applying Gamification in Education, which can be defined as the application of game design elements to learning activities. Its purpose is to motivate students by creating an engaging learning experience that can keep students focused on the learning task and its application in the classroom, is still in its emergent stages. Gamification is a great challenge for education, particularly in Higher Education Institutions (HEI) in such a traditional context, as is the case with courses like Management and Administration Business, Finance and Accounting, Marketing and Market Research, Chemistry, Accounting and Administration and Business Communication. This paper presents a study, applied in the 2016/2017 and 2017/2018 academic years, in which the teaching method focuses on a blended learning approach, through the implementation of a flipped classroom model and also through the introduction of online gamification activities such Kahoot! application. Kahoot is a game-based learning platform, used as educational technology that can easily be used for initial, formative and summative assessment of students’ knowledge using individual or collaborative team work mode, adding vitality, student engagement, and also meta-cognitive supports to higher education classrooms with limited instructor or student training required. The participants, in the study, were about 3 000 students of 17 different subjects from the aforementioned courses, of the Malaga University and Polytechnic of Porto. The results of this study suggest that this model improves student learning and are of relevance to researchers, educators and game-based learning designers.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Undergraduates’ perceptions of an online training to integrate conflicting sources in writing

Integrating conflicting information from multiple sources is an essential skill in today's society. This ability can be developed in the field of education through tasks such as writing a synthesis after reading sources that present contradictory views about a topic. In this work, we focus on the design of an intervention on argumentative writing through the Moodle platform with students from an online university. The participants were 44 students of the Degrees of Psychology and Education. As an academic task, they were asked to write different syntheses after reading two sources presenting conflicting positions on various educational topics. Students received training about the processes involved on the synthesis task. The training includes different tools, using videos, graphic mediators and exercises, including an explicit instruction, as well as a modelling about the different phases of the synthesis writing process, focusing especially on integration. In this work we present, on the one hand, the particularities of the intervention and, on the other, the perception of the participants in terms of: (1) the degree of improvement in their skills, (2) the usefulness of the aid received and (3) their degree of satisfaction with the intervention. The results show that, in general, students consider that their skills have improved significantly and that the aids provided have been effective. In addition, their satisfaction with the intervention is high.2022-2