The role of incidental variables of time in mood assessment

Determining what influences mood is important for theories of emotion and research on subjective well-being. We consider three sets of factors: activities in which people are engaged; individual differences; and incidental variables that capture when mood is measured, e.g., time-of-day. These three factors were investigated simultaneously in a study involving 168 part-time students who each responded 30 times in an experience sampling study conducted over 10 working days. Respondents assessed mood on a simple bipolar scale – from 1 (very negative) to 10 (very positive). Activities had significant effects but, with the possible exception of variability in the expression of mood, no systematic individual differences were detected. Diurnal effects, similar to those already reported in the literature, were found as was an overall “Friday effect.” However, these effects were small. Lastly, the weather had little or no influence. We conclude that simple measures of overall mood are not greatly affected by incidental variables.Affect; mood; experience sampling; diurnal effects; day-of-the-week; weather; multilevel analysis. leex

Modelos estadísticos y evaluación: tres estudios en educación

The educational system in Spain is undergoing a reorganization. At present, high-school graduates who want to enroll at a public university must take a set of examinations Pruebas de Aptitud para el Acceso a la Universidad (PAAU). A "new formula" (components, weights, type of exam,...) for university admission is been discussed. The present paper summarizes part of the research done by the author in her PhD. The context for this thesis is the evaluation of large-scale and complex systems of assessment. The main objectives were: to achieve a deep knowledge of the entire university admissions process in Spain, to discover the main sources of uncertainty and to promote empirical research in a continual improvement of the entire process. Focusing in the suitable statistical models and strategies which allow to high-light the imperfections of the system and reduce them, the paper develops, among other approaches, some applications of multilevel modeling.PAAU exams, admissions process, random coefficient models, variance component models, rater reliability

Fire spread across inner courtyards façades

2n premi al millor Treball de Fi de Grau del CGATE 2021.El present treball té per objecte l’estudi de la propagació d’incendis en façanes de patis interiors. El primer capítol aporta una visió general dels diferents processos físics i químics que intervenen en el foc i els conceptes de resistència i reacció al foc. La segona part del primer capítol és un repàs sobre l’evolució de la normativa de protecció contra incendis a l’Estat espanyol, des de l’aparició de la primera Norma Tecnològica l’any 1974 fins l’actual Codi Tècnic d’Edificació, d'ara endavant CTE. També s’inclou el cas particular de l’Ordenança Municipal de la ciutat de Barcelona. El segon capítol tracta la propagació del foc a través de façanes a partir de la classificació realitzada per Pilar Giraldo en la seva tesi doctoral. Aquesta, distingeix quatre mecanismes de propagació del foc per façana: A través de les finestres, a través del pas entre forjat i façana, a través de cambres ventilades i mitjançant revestiments combustibles. S’analitzen cadascun d’aquests mecanismes a partir d’imatges de casos reals i de com el CTE tracta la limitació de la propagació. En cada un d’aquests mecanismes es fa una reflexió sobre com Bombers afronta aquest fenomen a nivell operatiu. El tercer capítol tracta la propagació del foc a través de patis interiors, prenent com a punt de partida el que la comunitat científica ha establert respecte el moviment del fum en els edificis. Es classifiquen els patis interiors en tres tipus; patis de ventilació, celoberts i patis interiors d’illa. El fil conductor, com en el segon capítol, és l’exposició de casos reals i l’anàlisi del tractament que el CTE fa d’aquest problema, des del punt de vista de l’actuació de Bombers. La prioritat en cas d’incendi d’habitatge és el salvament de persones i en segon lloc l’extinció. Per aquest motiu, tracta la relació entre pati interior i caixa d’escala, per la repercussió directa sobre la seguretat en l’evacuació de les persones i el salvament. En el quart capítol s’exposen catorze casos d’incendi ocorreguts tots ells a Barcelona i l’Àrea Metropolitana en els anys 2007 a 2019. Són casos en que en què la propagació del foc pel pati interior i/o recinte de caixa d’escala ha tingut paper important en el desenvolupament de l’incendi. Un d’aquest casos, el cas 14, s’ha tractat de manera més profunda i és objecte d’anàlisi en el cinquè capítol. En el cinquè capítol és la continuació de l’estudi del cas 14 tractat en el quart capítol, a partir del modelatge i simulació computacional d’incendis amb el programa Fire Dynamics Simulator (FDS). Prèvia recollida de dades sobre l’edifici i circumstàncies de l’incendi, s’ha construït un model geomètric que reprodueix la geometria real de l’edifici, mobiliari existent, situació de les obertures i propietats calorífiques dels materials. Concretament s’ha modelat el pati interior, dos patis de ventilació un recinte d’escala protegida i les parts confrontants de les quatre finques afectades per l’incendi.The present work aims to study the spread of fires on inner courtyard facades. It begins with the collection and thinking about the information related to the spread of fire in inner courtyards that has been found in the recent technical literature. A set of real cases are analysed and studied; to continue to the computational modelling of a paradigmatic case. Next there is a detailed summary of each chapter. The first chapter deals with the spread of fire across the inner courtyards, taking as a starting point what the scientific community has established regarding the movement of smoke in buildings. There are three types of inner courtyards: Airy patio, light patio and inner courtyard of the block. The guiding thread is the exposition of real cases and the analysis of the treatment that the CTE makes of this problem from the point of view of the fire service. The priority in case of a housing fire is the rescuing of people, and secondly the extinction. For this reason, it deals with the relationship between the inner courtyard and the staircase due to the direct repercussion of the security in the evacuation of people. The second chapter presents fourteen cases of fire, all of which took place in Barcelona and the Metropolitan Area from 2007 to 2019. These are cases in which the spread of fire across the inner courtyard and/or box enclosure scale has played an important role in the development of the fire. One of these cases, Case 14, has been dealt with more depth in Chapter 3. The third chapter is a continuation of the study of case 14 that is analysed in the second chapter. Its analysis is based on the computer modelling and simulation of fires with the Fire Dynamics Simulator (FDS) program. After collecting data of the building and of the circumstances of the fire, a geometric model has been constructed that reproduces the actual geometry of the building, the existing furniture, the location of the openings and the calorific properties of the materials. It was a light patio, two small airy patios and a protected staircase with the adjoining parts of the four buildings affected by the fire were modelled. The general conclusions of the study are established when the previous chapters are completed. There are two areas of conclusions and some final recommendations. The conclusions of the analysis on the spread of fire and its real effects are explained. The conclusions of the computational analysis of FDS program about case 14 are presented. Finally, some recommendations are established in order to improve technical and functional parameters on inner courtyards.Award-winnin

University admission marks in Catalonia: Some highlights from the empirical research

The results of the examinations taken by graduated high school students who want to enrol at a Catalan university are here studied. To do so, the authors address several issues related to the equity of the system: reliability of grading, difficulty and discrimination power of the exams. The general emphasis is put upon the concurrent research and empirical evidence about the properties of the examination items and scores. After a discussion about the limitations of the exams' format and appropriateness of the instruments used in the study, the article concludes with some suggestions to improve such examinations.Admissions process, reliability of grading, index of difficulty, discrimination power

Unsupervised domain adaptation for bladder segmentation by U-net in Cone Beam CT

The main goal of this project is to accomplish the automatic segmentation of CBCT radiotherapy images using Deep Learning. Why? Because they are used in some process to treat cancer, in order to analyze where the radiation has to be applied. And we think that, by segmenting the images, the treatment applied to the patient could be executed more precisely, so the healthy tissues and organs around the tumor area would be less affected. This project is supervised by Benoît Macq and Eliott Brion, from ICTEAM research group at UCLouvain.Introduction: Radiotherapy is a medical treatment used to control or kill cancerous cells in cancer patients. At the beginning of the treatment planning process, the patient takes a CT scan in order to plan his radiation dose and, sometimes, he can take a Cone Beam CT scan some days after, right before receiving his radiation, to adjust his couch position for the delivery. The main difference between CT and CBCT scans is that the first one has a higher quality and contrast, and the second one is taken directly at the isocenter. As the treatment planning takes several days, when the patient receives his radiation his organs might not be in the same position as they were at the beginning, so the healthy tissues around the tumor area can receive more radiation than what it was planned and get damaged. Our aim is to implement an automatic segmentation of the bladder in CBCT 3D images using deep learning, in order to get a clearer idea of the position of those organs. Materials and Methods: In order to implement the segmentation we performed unsu- pervised domain adaptation between CT (the source) and CBCT 3D images (the target), as we didn?t have a large labeled CBCT dataset but we did for CT, as their segmenta- tion is already part of the treatment planning process. We have used a subset dataset of 120 patients: 60 CT and 60 CBCT of the male pelvic region. We have implemented a deep learning network using Unet as a segmenter and a regular CNN as a domain discriminator (an adversarial network), which also includes a gradient reversal layer. We have used the Dice score coefficient and the Hausdorff distance in order to evaluate the performance of our network and compare it with some previous works developed in the same field. Results: We have performed three main experiments, for which we have obtained the following DSC and Hausdorff distance (in voxels): (i) lower boundary: 0.383±0.260 and 36.47, (ii) upper boundary: 0.717±0.177 and 27.44, (iii) unsupervised domain adapta- tion: 0.623±0.149 and 39.18. With this implementation we have closed the gap between training the network only on CT and only on CBCT by a 72%. Conclusions: Cone Beam CT image segmentation using unsupervised domain adap- tation proves to be an improving methodology in radiotherapy and presents different applications in other fields

Efficient algorithms for passive network measurement

Network monitoring has become a necessity to aid in the management and operation of large networks. Passive network monitoring consists of extracting metrics (or any information of interest) by analyzing the traffic that traverses one or more network links. Extracting information from a high-speed network link is challenging, given the great data volumes and short packet inter-arrival times. These difficulties can be alleviated by using extremely efficient algorithms or by sampling the incoming traffic. This work improves the state of the art in both these approaches. For one-way packet delay measurement, we propose a series of improvements over a recently appeared technique called Lossy Difference Aggregator. A main limitation of this technique is that it does not provide per-flow measurements. We propose a data structure called Lossy Difference Sketch that is capable of providing such per-flow delay measurements, and, unlike recent related works, does not rely on any model of packet delays. In the problem of collecting measurements under the sliding window model, we focus on the estimation of the number of active flows and in traffic filtering. Using a common approach, we propose one algorithm for each problem that obtains great accuracy with significant resource savings. In the traffic sampling area, the selection of the sampling rate is a crucial aspect. The most sensible approach involves dynamically adjusting sampling rates according to network traffic conditions, which is known as adaptive sampling. We propose an algorithm called Cuckoo Sampling that can operate with a fixed memory budget and perform adaptive flow-wise packet sampling. It is based on a very simple data structure and is computationally extremely lightweight. The techniques presented in this work are thoroughly evaluated through a combination of theoretical and experimental analysis.Postprint (published version

Asessing public policies. The case of education in Europe and the interaction between personal and institutional factors

The paper deals with the comparative study of European citizens’ satisfaction with the state of education in their respective countries. Individual and contextual effects are tested applying multilevel analysis. The results show that educational public policies (level of decentralization, degree of comprehensiveness and public spending) as well as the students’ social environment (socioeconomic and cultural status) have a sound impact on the opinions about the state of education.Education, public opinion, public policies, multilevel analysis, comparative studies, European Social Survey