Relevance-based language modelling for recommender systems

This is the author’s version of a work that was accepted for publication in Journal Information Processing and Management: an International Journal. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal Information Processing and Management: an International Journal, 49, 4, (2013) DOI: 10.1016/j.ipm.2013.03.001Relevance-Based Language Models, commonly known as Relevance Models, are successful approaches to explicitly introduce the concept of relevance in the statistical Language Modelling framework of Information Retrieval. These models achieve state-of-the-art retrieval performance in the pseudo relevance feedback task. On the other hand, the field of recommender systems is a fertile research area where users are provided with personalised recommendations in several applications. In this paper, we propose an adaptation of the Relevance Modelling framework to effectively suggest recommendations to a user. We also propose a probabilistic clustering technique to perform the neighbour selection process as a way to achieve a better approximation of the set of relevant items in the pseudo relevance feedback process. These techniques, although well known in the Information Retrieval field, have not been applied yet to recommender systems, and, as the empirical evaluation results show, both proposals outperform individually several baseline methods. Furthermore, by combining both approaches even larger effectiveness improvements are achieved.This work was funded by Secretaría de Estado de Investigación, Desarrollo e Innovación from the Spanish Government under Projects TIN2012-33867 and TIN2011-28538-C02

Model-Driven Technologies for Data Mining Democratisation

Data mining techniques allow discovering insights previously hidden in data from a domain. However, these techniques demand very specialised skills. People often lack these skills, which hinders data mining democratisation. To alleviate this situation, we defined a model-driven framework and some domain-specific languages that contribute to the democratisation of data mining. Here we summarise these contributions

Detección precoz de pacientes con degeneración macular asociada a la edad en farmacias comunitarias de la provincia de Pontevedra

OBJETIVOS Detección precoz de pacientes sospechosos de padecer DMAE. Cuantificar la respuesta del paciente en los casos de derivación. Establecer posibles factores de riesgo relacionados con la enfermedad en la población estudiada.MÉTODOS Estudio descriptivo en 25 farmacias de la provincia de Pontevedra, desde marzo a mayo de 2011. Sujetos: mayores de 50 años, no diagnosticados, sin problemas mentales y no dependientes. La muestra, aleatoria, se estratificó por grupos de edad. En caso de encontrar alteraciones visuales sospechosas de DMAE, se recomendaba la consulta al oftalmólogo. Al cabo de un mes se le llamaba por teléfono y se registraba el resultado. En caso de no haberla realizado, se le recordaba la importancia de dicha visita y se le llamaba transcurrido un mes más, registrándose entonces el resultado o la no visita.RESULTADOS Se hicieron 481 pruebas (48,4% hombres y 51,6% mujeres). Media de edad, 67,3 años (DE 9,5). Antecedentes familiares de alteraciones visuales en 125 (27,2%). Se derivaron al oftalmólogo 51 posibles positivos (10,6%), de los que tan sólo en 8 (15,7%) se obtuvo confirmación de su visita al médico. Ninguno resultó positivo. Las rela

Evaluation of mechanical properties of FDM components reinforced with fibre

[EN] This research analyses the influence of different parameters of the Fused Deposition Modelling process with continuous carbon fibre reinforcement upon tensile strength of manufactured parts. For that, the appropriate behaviour of specimens designed according to ISO 527 standard was verified, in a preliminary test. Hereafter, a full factorial Design of Experiment was proposed with five parameters and two levels. After manufacturing and testing the specimens, a regression including all possible interactions of the parameters was performed with their tensile results. This model was optimized, considering the terms with the highest statistical significance (p-value less than 0.05), so that a simplified model of 14 terms with an r-squared of 97.5% was obtained. Thanks to this research the tensile response of a printed part as a function of the chosen manufacturing parameters can be predicted in advance.S

Influence of Post-Processing on the Properties of Multi-Material Parts Obtained by Material Projection AM

[EN] The great geometric complexity that additive manufacturing allows in parts, together with the possibility of combining several materials in the same part, establishes a new design and manufacturing paradigm. Despite the interest of many leading sectors, the lack of standardization still makes it necessary to carry out characterization work to enjoy these advantages in functional parts. In many of these techniques, the process does not end with the end of the machine cycle, but different post-processing must be carried out to consider the part finished. It has been found that the type of post process applied can have a similar effect on part quality as other further studied process parameters. In this work, the material projection technique was used to manufacture multi-material parts combining resins with different mechanical properties. The influence of different post-processing on the tensile behavior of these parts was analyzed. The results show the detrimental effect of ultrasonic treatment with isopropyl alcohol in the case of the more flexible resin mixtures, being advisable to use ultrasonic with mineral oil or furnace treatment. For more rigid mixtures, the furnace is the best option, although the other post-processing techniques do not significantly deteriorate their performance.S

Aproximación a la caracterización reológica y mecánica de materiales en fresco de base cemento para fabricación aditiva

Resumen El presente trabajo tiene como objetivo caracterizar las principales propiedades mecánicas de materiales de base cemento en fresco para fabricación aditiva. Las características especiales de dosificación del material de base cemento para que se considere imprimible, hace necesario el desarrollo de nuevos procedimientos de ensayo. Estos procedimientos, alternativos a los descritos en las normas existentes, deben permitir una caracterización rápida y completa del material. Mediante los ensayos mecánicos a compresión simple, asistidos mediante métodos de correlación de imágenes, se puede obtener una caracterización completa en las etapas tempranas del material en fresco. Alternativamente, es de gran interés la búsqueda de correlaciones con otros ensayos de caracterización que sean fácilmente implementables en el control de calidad del proceso de impresión. Estas propiedades mecánicas, junto con las propiedades reológicas del material en fresco son utilizadas para el calibrado de un modelo mecánico de evolución del comportamiento de material frente al fallo plástico. De esta forma, se obtiene el modelo mecánico del material necesario para simular el proceso de impresión 3D, que permite evaluar la imprimabilidad de las piezas objeto de estudio.Abstract The aim of this work is to characterise the main mechanical properties of fresh cement- based materials for additive manufacturing. The special dosage characteristics of the cement-based material to be considered printable make it necessary to develop new test procedures. These procedures, as an alternative to those described in the existing standards, should allow a rapid and complete characterisation of the material. By means of simple mechanical compression tests and digital image correlation methods, a complete characterisation can be obtained in the early stages of the fresh material. Alternatively, it is of great interest to search for correlations with other characterisation tests that can be easily implemented in the quality control of the printing process. These mechanical properties, with the rheological properties of the fresh material, are used to calibrate a mechanical model of the evolution of the plastic failure of the material. In this way, the mechanical model of the material necessary to simulate the 3D printing process is obtained, which allows to evaluate the printability of an object.Laburpena Lan honen helburua da fabrikazio gehigarrirako zementu-oinarri freskoko materialen propietate mekaniko nagusiak ezaugarritzea. Inprimagarritzat jotzeko zementu-oinarriko materialaren dosifikazioaren ezaugarri bereziak direla eta, saiakuntza-prozedura berriak garatu behar dira. Prozedura horiek, dauden arauetan deskribatutakoen alternatiboak, materialaren karakterizazio azkar eta osoa ahalbidetu behar dute. Konpresio sinpleko saiakuntza mekanikoen bidez, irudien korrelazio-metodoen bidez lagunduta, karakterizazio osoa lor daiteke material freskoaren etapa goiztiarretan. Txandaka, oso interesgarria da inprimaketa-prozesuaren kalitate-kontrolean erraz inplementatu daitezkeen beste karakterizazio-saiakuntza batzuekin korrelazioak bilatzea. Propietate mekaniko horiek, freskoan dagoen materialaren propietate erreologikoekin batera, materialak akats plastikoaren aurrean duen portaeraren eboluzio-eredu mekaniko bat kalibratzeko erabiltzen dira. Horrela, materialaren eredu mekanikoa lortzen da, 3D inprimaketa-prozesua simulatzeko beharrezkoa dena, aztergai diren piezen inprimagarritasuna zehazteko helburuarekin

Funciones de Green y aplicaciones en Física

En este trabajo se presenta el método de las funciones de Green, una técnica matemática para la resolución de ecuaciones diferenciales con condiciones de contorno inhomogéneos. Posteriormente, se aplica al estudio de las principales ecuaciones de las diferentes ramas de la física: clásica, cuántica y electromagnetismo. La base de este método se centra en determinar la función de Green asociada a una determinada ecuación diferencial. Esta función es la solución a la ecuación diferencial para un término inhomogéneo que viene representado por la delta de Dirac δ(x − x'). Por lo cual, el trabajo se centra en resolver ecuaciones en las que interviene un término delta de Dirac. En este trabajo, puramente teórico, se obtienen las funciones de Green relativas a las principales ecuaciones en física-matemática que se han visto en el Grado. Estas funciones se podrán utilizar para la resolución posterior del correspondiente problema inhomogéneo.In this work is presented the method of the functions of Green, a mathematical technique for solving differential equations with inhomogeneous contour conditions. Subsequently, it is applied to the study of the main equations of the different branches of Physics: classical, quantum and electromagnetism. The basis of this method focuses on determining the function of Green associated with a determined differential equation. This function is the solution to the equation for an inhomogeneous term that is represented by the Dirac delta δ(x−x 0 ). Therefore, the work focuses on solving differential equations in which a Dirac delta term is involved. In this work, purely theoretical, we obtain the functions of Green related to the main equations in physics-mathematics which have been seen in the Degree. These functions can be used for the subsequent resolution of the corresponding inhomogeneous problem.Grado en Físic

Modelos aditivos generalizados

Este trabajo se centra en el estudio y aplicación del Modelo Aditivo Generalizado el cual intenta aprovechar las ventajas del enfoque paramétrico y no paramétrico de otros modelos. Por esta razón, primero realizamos un breve resumen del Modelo Lineal Generalizado. A continuación, introducimos el Modelo Aditivo Generalizado y su estructura, caracterizada por el uso de funciones suaves sobre las variables explicativas que permite relaciones no lineales entre éstas y la variable objetivo. Con el fin de obtener dichas funciones suaves, recopilamos diferentes técnicas, entre las que destaca el uso de los splines de regresión cúbicos, haciendo hincapié en las diferencias de las mismas. Seguidamente, introducimos el concepto de criptomoneda y comentamos los problemas que presenta su modelización estadística. Por último, haciendo uso del software estadístico R, comprobamos si la implementación de las técnicas descritas pueden ser beneficiosas a la hora de tomar decisiones relacionadas con la comercialización de las criptomonedas.This work is focused on the study and application of the Generalized Additive Model which tries to take advantage of the parametric and non-parametric approach of other models. For this reason, we first make a brief summary of the Generalized Linear Model. Next, we introduce the Generalized Additive Model and its structure, characterized by the use of smooth functions on the independent variables that allow non-linear relationships between them and the response variable. In order to obtain these smooth functions, we compile different techniques, among which the cubic regression splines stand out, emphasizing their differences. Next, we introduce the concept of cryptocurrency and discuss the problems presented by its statistical modeling. Finally, using the statistical software R, we check whether the implementation of the techniques described can be beneficial when making decisions related to the commercialization of cryptocurrencies.Universidad de Sevilla. Grado en Estadístic

Long-term treatment of patients with HIV-1: the role of atazanavir

Miguel Ángel Artacho1, Pablo Barreiro2, José Vicente Fernández-Montero21Department of Internal Medicine, Hospital Universitario Gregorio Marañón, Madrid, Spain; 2Department of Infectious Diseases, Hospital Carlos III, Madrid, SpainBackground: The introduction of highly-active antiretroviral therapy (HAART) remains a major milestone in the management of HIV-infected patients. Protease inhibitors (PI) are commonly used as part of triple combinations, given that to antiviral potency, better tolerance and convenience has been achieved in recent years.Objective: To summarize and update evidence-based information about atazanavir (ATV) on initial, simplification, and rescue interventions in HIV patients.Methods: Review of observational and randomized trials reported in medical conferences, peer-reviewed journals, and treatment guidelines.Results: ATV is a second-generation PI, which has shown across studies potent antiviral activity and high genetic barrier, both in HAART-naïve patients or after virological failure. Indulgent metabolic profile, in terms of insulin glucose and lipid levels, adds value to this drug for the long-term management of HIV infection.Keywords: atazanavir, HAART, protease inhibitor