p-probabilistic k-anonymous microaggregation for the anonymization of surveys with uncertain participation

We develop a probabilistic variant of k-anonymous microaggregation which we term p-probabilistic resorting to a statistical model of respondent participation in order to aggregate quasi-identifiers in such a manner that k-anonymity is concordantly enforced with a parametric probabilistic guarantee. Succinctly owing the possibility that some respondents may not finally participate, sufficiently larger cells are created striving to satisfy k-anonymity with probability at least p. The microaggregation function is designed before the respondents submit their confidential data. More precisely, a specification of the function is sent to them which they may verify and apply to their quasi-identifying demographic variables prior to submitting the microaggregated data along with the confidential attributes to an authorized repository. We propose a number of metrics to assess the performance of our probabilistic approach in terms of anonymity and distortion which we proceed to investigate theoretically in depth and empirically with synthetic and standardized data. We stress that in addition to constituting a functional extension of traditional microaggregation, thereby broadening its applicability to the anonymization of statistical databases in a wide variety of contexts, the relaxation of trust assumptions is arguably expected to have a considerable impact on user acceptance and ultimately on data utility through mere availability.Peer ReviewedPostprint (author's final draft

Parallelization of the interpolation process in the Koetter-Vardy soft-decision list decoding algorithm

List decoding is a decoding strategy that provides a set of codewords at the output of the channel decoder. Since this technique corrects errors beyond the correcting bound of the code, upper layers in the application or in the communications protocol can choose the appropriate candidate codeword among the elements of the set. The Koetter-Vardy algorithm is a soft-decision decoding algorithm for Reed-Solomon codes. It is based on two sequential processes: interpolation and factorization. In most applications it is interesting to efficiently decode in real time. This paper discusses some parallelization results about the interpolation process, which is the highest time-consuming part of the Koetter-Vardy algorithm.Postprint (published version

Incremental k-Anonymous microaggregation in large-scale electronic surveys with optimized scheduling

Improvements in technology have led to enormous volumes of detailed personal information made available for any number of statistical studies. This has stimulated the need for anonymization techniques striving to attain a difficult compromise between the usefulness of the data and the protection of our privacy. k-Anonymous microaggregation permits releasing a dataset where each person remains indistinguishable from other k–1 individuals, through the aggregation of demographic attributes, otherwise a potential culprit for respondent reidentification. Although privacy guarantees are by no means absolute, the elegant simplicity of the k-anonymity criterion and the excellent preservation of information utility of microaggregation algorithms has turned them into widely popular approaches whenever data utility is critical. Unfortunately, high-utility algorithms on large datasets inherently require extensive computation. This work addresses the need of running k-anonymous microaggregation efficiently with mild distortion loss, exploiting the fact that the data may arrive over an extended period of time. Specifically, we propose to split the original dataset into two portions that will be processed subsequently, allowing the first process to start before the entire dataset is received, while leveraging the superlinearity of the microaggregation algorithms involved. A detailed mathematical formulation enables us to calculate the optimal time for the fastest anonymization, as well as for minimum distortion under a given deadline. Two incremental microaggregation algorithms are devised, for which extensive experimentation is reported. The theoretical methodology presented should prove invaluable in numerous data-collection applications, including largescale electronic surveys in which computation is possible as the data comes in.Peer ReviewedPostprint (published version

On the revocation of malicious users in anonymous and non-traceable VANETs

For the proper performance of Vehicular Ad-hoc NETworks (VANETs) it is essential to protect the service against malicious nodes aiming at disrupting the proper operation by injecting fake, invalid data into the network. It is common to define a traditional identity-based authentication for vehicles, which are loaded with individual credentials. However, the use of these credentials in VANETs may allow vehicle tracking and thus violate users’ privacy, a risk that can be overcome by means of anonymity schemes. This comes at the expenses, however, of on the one hand preventing VANET authorities from identifying malicious users and revoking them from the network, or on the other hand to avoid anonymity of users in front of the CA thus to allow their revocation. In this work, we describe a novel revocation scheme that is able to track and revoke specific users only after a number of complaints have been received while otherwise guaranteeing vehicle’s anonymity.This work was partially supported by the Spanish Ministerio de Economía y Competitividad, the Spanish Comisión Interministerial de Ciencia y Tecnología, the Spanish Ministerio de Industria, Energía y Turismo, the Generalitat de Catalunya and European FEDER funds under the projects: MINECO TUERI (TIN2011-25452), CICYT TAMESIS (TEC2011-22746), INNPACTO DEPHISIT (IPT-2012-0585-370000), CONSOLIDER ARES (CSD2007-00004), as well as the grant 2009 SGR-1362 to consolidated research groups, the funding of which is gratefully acknowledged

Efficient k-anonymous microaggregation of multivariate numerical data via principal component analysis

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/k-Anonymous microaggregation is a widespread technique to address the problem of protecting the privacy of the respondents involved beyond the mere suppression of their identifiers, in applications where preserving the utility of the information disclosed is critical. Unfortunately, microaggregation methods with high data utility may impose stringent computational demands when dealing with datasets containing a large number of records and attributes. This work proposes and analyzes various anonymization methods which draw upon the algebraic-statistical technique of principal component analysis (PCA), in order to effectively reduce the number of attributes processed, that is, the dimension of the multivariate microaggregation problem at hand. By preserving to a high degree the energy of the numerical dataset and carefully choosing the number of dominant components to process, we manage to achieve remarkable reductions in running time and memory usage with negligible impact in information utility. Our methods are readily applicable to high-utility SDC of large-scale datasets with numerical demographic attributes.Peer ReviewedPostprint (author's final draft

A protocol for data exchange with free samples using smart contracts

Distrust between data providers and data consumers is one of the main obstacles hampering digitaldata commerce to take off. Data providers want to get paid for what they offer, while data consumers want to know exactly what are they paying for before actually paying for it. In this paper, we summarize a protocol that overcomes this obstacle by building trust based on two main ideas. First, a probabilistic verification protocol, where some random samples of the real dataset are shown to buyers in order to allow them to make an assessment before committing any payment; and second a guaranteed, protected payment process, enforced with smart contracts on a public blockchain, that guarantees the payment of the data if and only if the data provided meets the agreed terms, and that refunds honest players otherwise.This research has been funded by i3Market (H2020- ICT-2019-2 grant number 871754). This work is also supported by the TCO-RISEBLOCK (PID2019-110224RBI00), ARPASAT (TEC2015-70197-R), Project RTI2018- 102112-B-I00 (AEI/FEDER,UE) and by the Generalitat de Catalunya grant 2014-SGR-1504Postprint (author's final draft

Aprendizaje activo con PBL en el diseño instruccional de Expressió Gràfica

Numerosos estudios respaldan los efectos positivos del aprendizaje activo en la mejora de la motivación y las actitudes del alumnado en el aprendizaje global y la reducción de las diferencias en las calificaciones. Esta investigación tiene como objetivo aumentar nuestra comprensión sobre los efectos del aprendizaje activo, aplicando metodologías PBL, en el alumnado para aumentar la motivación en varios grupos de clase de una asignatura de Expressió Gràfica. Para ello se realiza una comparación cuantitativa de sus calificaciones. Los resultados muestran que el desarrollo de las actividades didácticas propuestas, además de promover el pensamiento creativo e innovador, ha contribuido a la mejora en la visualización de modelos geométricos y la comprensión de enunciados y soluciones

El impacto de las políticas de evaluación del profesorado en la posición en los ránquines universitarios: el caso de la Universidad Politécnica de Cataluña

La universidad española ha afrontado con éxito el tránsito entre una universidad clásica, eminentemente docente, y una universidad moderna, en la que la investigación juega un papel esencial. Gran parte de este éxito reside en la instauración de sistemas de evaluación. No obstante, a pesar de los indiscutibles logros, aún queda un camino importante por recorrer para situarla en los lugares que le corresponden en las clasificaciones internacionales por el lugar que ocupamos dentro de los países de nuestro entorno. La Universidad Politécnica de Cataluña dispone de un modelo de evaluación docente, así como de información sobre la actividad investigadora del profesorado. Ello ha permitido implementar un modelo de evaluación global, que presentamos en este artículo. Asimismo, usando una muestra de 4.996 evaluaciones individuales de unos 1.700 profesores, analizamos la evolución temporal de las evaluaciones de los años 2011, 2012 y 2013, estudiamos si existen diferencias entre los ámbitos de conocimiento y examinamos si existe una relación entre la productividad académica así evaluada y la posición de la universidad en los ránquines universitarios. Los datos de este estudio corroboran que el modelo ha tenido éxito, al haber permitido que la universidad progresara en el ranquin Quacquarelli Symonds del puesto 350 al 337. Spanish universities have moved from a classical model, a teaching university, to a modern one, in which research is essential. Part of this success is due to the implementation of quality assessment policies. Nonetheless, and in spite of this, there is still a long way to place it at the level of similar countries in university rankings. The Universidad Politécnica de Cataluña has an evaluation model of the teaching performance of its staff, and also abundant information of their research. This has allowed implementing a global evaluation model. Here we present the evaluation model. Also, using 4,996 individual evaluations corresponding to about 1,700 academic staff members we analyze the evolution of the results of the evaluations of years 2011, 2012 and 2013, we study if there are differences among the various academic fields, and we examine if there exists a correlation between the evolution of the academic productivity measured using this model and the position of the university in the university rankings. We show that this model has allowed the university to improve its classification in the Quacquarelli Symonds Top University Ranking, from position 350 to 337.Peer ReviewedPostprint (published version

Biodegradable FeMnSi sputter-coated macroporous polypropylene membranes for the sustained release of drugs

Pure Fe and FeMnSi thin films were sputtered on macroporous polypropylene (PP) membranes with the aim to obtain biocompatible, biodegradable and, eventually, magnetically-steerable platforms. Room-temperature ferromagnetic response was observed in both Fe- and FeMnSi-coated membranes. Good cell viability was observed in both cases by means of cytotoxicity studies, though the FeMnSi-coated membranes showed higher biodegradability than the Fe-coated ones. Various strategies to functionalize the porous platforms with transferrin-Alexa Fluor 488 (Tf-AF488) molecules were tested to determine an optimal balance between the functionalization yield and the cargo release. The distribution of Tf-AF488 within the FeMnSi-coated PP membranes, as well as its release and uptake by cells, was studied by confocal laser scanning microscopy. A homogeneous distribution of the drug within the membrane skeleton and its sustained release was achieved after three consecutive impregnations followed by the addition of a layer made of gelatin and maltodextrin, which prevented exceedingly fast release. The here-prepared organic-inorganic macroporous membranes could find applications as fixed or magnetically-steerable drug delivery platforms

HOP LEARNING: An experience of transversal teaching innovation in telecommunication engineering degrees at the ETSE of the Universitat de València and its impact beyond the classroom

[EN] The needs for teaching innovation in the field of telecommunications engineering go beyond the teaching guide itself and its implementations. The innovation presented here has been developed over the last three academic years to show the benefit of using professional communication systems platforms in formal teaching. This paper analyses the effects measured in previous implementations using project-based learning methodology and formative assessment against the usual context of qualitative assessment. It shows how the appropriate use of these platforms improves students' perception of related content through the analysis of LIKERT surveys. It also presents transfer cases conducted thanks to the inclusion of professional engineering agents in the development of classes and the impact on the design awareness of engineering students and awareness actions on the use of communication platforms in non-university environments.[ES] Las necesidades de innovación docente en el ámbito de la ingeniería de telecomunicaciones van más allá de la propia guía docente y sus implementaciones. La innovación que aquí se presenta se ha desarrollado a lo largo de los últimos 3 cursos académicos para mostrar el beneficio del uso de plataformas profesionales de sistemas de comunicación en la docencia reglada. En este trabajo se analizan los efectos medidos en implementaciones anteriores utilizando metodología de aprendizaje basado en proyectos y evaluación formativa frente al contexto habitual de evaluación cualitativa. Muestra cómo el uso adecuado de estas plataformas mejora la percepción de los alumnos sobre los contenidos relacionados a través del análisis de las encuestas LIKERT. También se presentan los casos de transferencia llevados a cabo gracias a la inclusión de agentes profesionales de la ingeniería en el desarrollo de las clases y el impacto en la conciencia de diseño de los estudiantes de ingeniería y las acciones de sensibilización sobre el uso de plataformas de comunicación en entornos no universitarios.Este trabajo ha sido financiado por el Vicerectorat de Transformació Docent i Formació Permanent de la Universitat de València través del Projecte d’Innovació Educativa per al curs 2022-2023 UV-SFPIE_PID-2079731Pérez Soler, J.; Soriano Asensi, A.; Suárez Zapata, A.; Herraiz García, R.; Amaro Perez, A.; Felici Castell, S.; García Olcina, R.... (2023). HOP LEARNING: una experiencia de innovación docente transversal en grados de ingeniería de telecomunicación en la ETSE de la Universitat de València y su impacto mas allá del aula. Editorial Universitat Politècnica de València. 178-189. https://doi.org/10.4995/INRED2023.2023.1664517818