Multiclass Data Segmentation using Diffuse Interface Methods on Graphs

We present two graph-based algorithms for multiclass segmentation of high-dimensional data. The algorithms use a diffuse interface model based on the Ginzburg-Landau functional, related to total variation compressed sensing and image processing. A multiclass extension is introduced using the Gibbs simplex, with the functional's double-well potential modified to handle the multiclass case. The first algorithm minimizes the functional using a convex splitting numerical scheme. The second algorithm is a uses a graph adaptation of the classical numerical Merriman-Bence-Osher (MBO) scheme, which alternates between diffusion and thresholding. We demonstrate the performance of both algorithms experimentally on synthetic data, grayscale and color images, and several benchmark data sets such as MNIST, COIL and WebKB. We also make use of fast numerical solvers for finding the eigenvectors and eigenvalues of the graph Laplacian, and take advantage of the sparsity of the matrix. Experiments indicate that the results are competitive with or better than the current state-of-the-art multiclass segmentation algorithms.Comment: 14 page

Modeling tuberculosis transmission in urban cities through agent-based simulation: the case of Barcelona

Tuberculosis remains one of the world’s deadliest infectious diseases. About one-third of the world’s population is infected with tuberculosis bacteria. Understanding the dynamics of transmission at different spatial scales is critical to progress in its control. We present an agent-based model for tuberculosis epidemics in Barcelona, which has an observatory on this disease. Our model considers high heterogeneity within the population, including risk factors for developing an active disease, and it tracks the individual behavior once diagnosed. We incorporated the immunodeficiency and smoking/alcoholism, as well as the individual’s origin (foreigner or not) for its contagion and infection as risks factors. We implemented the model in Netlogo, a useful tool for interaction with physicians. However, the platform has some computational limitations, and we propose a solution to overcome them.Peer ReviewedPostprint (published version

As características dos milénios e centenários face à evolução das tecnologias e a sua influência na compra de produtos no sector dos seguros

The Digital Talent Agency in its November 2019 publication, indicates among other things that by the year 2025 the millennials and centennial generations will represent 70% and 30% of the global workforce respectively with common factor, "the connection to the internet from their Smartphone". This situation allowed us to identify the main problem of the research also taking into account the experiences as instructors of the Financial Services Center and specifically the Risk Management program. The young people of the described generations consider that it is not important to acquire insurance because they consider that doing so is an unnecessary expense and that the information, they have about it is not decisive to acquire it. This research aims to show the perception, interest, knowledge and acquisition of financial products in the insurance sector in the aforementioned generations, paying special attention to the role played by technological development in these purchasing processes. The methodology used is descriptive with a mixed approach (quantitative and qualitative); the collection of information was done through surveys to a representative sample in the city of Bogota - Chapinero, and interviews to commercial directors of the main insurance companies in the country. The collection of information made it possible to measure the impact of age, people's consumer culture, traditional and/or digital means of purchase and how these affect the decisions to purchase products in the insurance sector.La Agencia de Talento Digital en su publicación de noviembre del 2019, indica entre otras cosas que para el año 2025 las generaciones millennials y centennial representaran el 70% y 30% de la fuerza laboral mundial respectivamente con factor común, “la conexión a internet desde su Smartphone”. Esta situación permitió identificar la problemática principal de la investigación teniendo en cuenta además las experiencias como instructores del Centro de Servicios Financieros y específicamente el programa de Gestión de riesgos. Los jóvenes de las generaciones descritas estiman que no es importante adquirir un seguro en razón a que consideran que hacerlo es un gasto innecesario y que la información que tienen al respecto no es determinante para adquirirlo. Esta investigación, pretende mostrar la percepción, el interés, conocimiento y adquisición de productos financieros del sector asegurador en las generaciones mencionadas, teniendo especial atención en el papel que juega el desarrollo tecnológico en dichos procesos de compra. La metodología utilizada es de tipo descriptivo con un enfoque mixto (cuantitativa y cualitativa); la recolección de información se realizó a través de encuestas, a una muestra representativa en la cuidad de Bogotá - localidad de Chapinero, y entrevistas a Directores comerciales de las principales aseguradoras del país. La recolección de la información permitió permitió medir el impacto que tiene la edad, la cultura de consumo de las personas, los medios de compra tradicional y/o digital y cómo afectan estos en las decisiones de adquisición de productos del sector asegurador.A Agência de Talento Digital na sua publicação de Novembro de 2019, indica entre outras coisas que até ao ano 2025 as gerações milenares e centenárias representarão 70% e 30% da força de trabalho global respectivamente com factor comum, "ligação à Internet a partir do seu Smartphone". Esta situação permitiu-nos identificar o principal problema da investigação tendo também em conta as experiências como instrutores do Centro de Serviços Financeiros e especificamente o programa de Gestão de Riscos. Os jovens das gerações descritas acreditam que não é importante adquirir um seguro porque consideram que fazê-lo é uma despesa desnecessária e que a informação que têm sobre ele não é decisiva para o adquirir. Esta investigação visa mostrar a percepção, interesse, conhecimento e aquisição de produtos financeiros no sector dos seguros nas gerações acima mencionadas, prestando especial atenção ao papel desempenhado pelo desenvolvimento tecnológico nestes processos de compra. A metodologia utilizada é descritiva com uma abordagem mista (quantitativa e qualitativa); a recolha de informação foi feita através de inquéritos a uma amostra representativa na cidade de Bogotá - Chapinero, e entrevistas a directores comerciais das principais companhias de seguros do país. A recolha de informação permitiu-nos medir o impacto da idade, a cultura de consumo das pessoas, os meios de compra tradicionais e/ou digitais e como estes afectam as decisões de compra de produtos no sector dos seguro