Flavored axions and the flavor problem

A Peccei-Quinn~(PQ) symmetry is proposed, in order to generate in the Standard Model~(SM) quark sector a realistic mass matrix ansatz with five texture-zeros. Limiting our analysis to Hermitian mass matrices we show that this requires a minimum of 4 Higgs doublets. This model allows assigning values close to 1 for several Yukawa couplings, giving insight into the origin of the mass scales in the SM. Since the PQ charges are non-universal the model features Flavor-Changing Neutral Currents~(FCNC) at the tree level. From the analytical expressions for the FCNC we report the allowed region in the parameter space obtained from the measurements of branching ratios of semileptonic meson decays.Comment: 20 pages, 2 figure

ShinyWYSIWYG: a Shiny What You See Is What You Get editor

For any computer application, having a graphical user interface (GUI) potentially increases its usability and scope. In the case of the R language, one of the most used alternatives is the Shiny [1] library. Shiny is an R package that facilitates the creation of interactive web applications directly from R. However, using Shiny requires a certain level of knowledge of R programming. Looking at CRAN’s Task Views, it is easy to note that the R community brings together a variety of specialists in various fields such as biologists, agronomists, economists, among others. It is therefore crucial that R development tools maximize the level of programmatic simplicity to ease the start of the learning ramp. In order to further facilitate the process of developing a user-friendly GUI, and tackling this learning gap, here we present the ShinyWYSIWYG application. ShinyWYSIWYG is a visual editor that allows the user, using the drag and drop technique, inserting the various fields that Shiny provides as input and output, by selecting the desired size and position for each field. Once the user interface is generated, ShinyWYSIWYG also eases the development of the server logic.Sociedad Argentina de Informática e Investigación Operativ

ShinyWYSIWYG: a Shiny What You See Is What You Get editor

For any computer application, having a graphical user interface (GUI) potentially increases its usability and scope. In the case of the R language, one of the most used alternatives is the Shiny [1] library. Shiny is an R package that facilitates the creation of interactive web applications directly from R. However, using Shiny requires a certain level of knowledge of R programming. Looking at CRAN’s Task Views, it is easy to note that the R community brings together a variety of specialists in various fields such as biologists, agronomists, economists, among others. It is therefore crucial that R development tools maximize the level of programmatic simplicity to ease the start of the learning ramp. In order to further facilitate the process of developing a user-friendly GUI, and tackling this learning gap, here we present the ShinyWYSIWYG application. ShinyWYSIWYG is a visual editor that allows the user, using the drag and drop technique, inserting the various fields that Shiny provides as input and output, by selecting the desired size and position for each field. Once the user interface is generated, ShinyWYSIWYG also eases the development of the server logic.Sociedad Argentina de Informática e Investigación Operativ

Influencia de algunas variables en el ensayo a compresión de probetas testigo en un hormigón autocompactante

La estimación de la resistencia a compresión a través de la evaluación de probetas testigo depende de numerosas variables, entre ellas, el diámetro de la probeta testigo, la dirección de extracción en relación con la dirección del hormigonado, el estado de humedad de la probeta testigo en el momento de ser ensayada, la esbeltez de la probeta testigo, la armadura embebida en la probeta testigo y la edad del hormigón investigado. El objetivo de este trabajo experimental ha sido evaluar, para un hormigón autocompactante, el efecto que presentan algunas de estas variables en el resultado de la resistencia a compresión de las probetas testigo. Estos efectos pueden ser muy diferentes de los que ocurren en el hormigón vibrado, debido a que no existe en este caso un procedimiento específico para la compactación de las probetas moldeadas. Igualmente se han analizado los posibles factores de corrección utilizados en la estimación de la resistencia a compresión de la probeta moldeada a través de la resistencia a compresión de la probeta testigo. Para ello se han fabricado 30 bloques de 50x50x100 cm en HAC cubriendo un amplio rango de resistencias (20 MPa - 80 MPa), de los cuales se extrajeron un total de 360 probetas testigo. Paralelamente a la ejecución de los bloques se han fabricado 90 probetas cilíndricas de 15 30 cm que posteriormente fueron ensayadas a compresión a la misma edad que las probetas testigo (28 días). Los resultados muestran que algunas de las variables incíden de forma muy diferente en estos hormigones que en los hormigones convencionales, en especial la dirección de extracción y el coeficiente de paso para considerar la resistencia en probeta moldeada

Validation of the CALL score as a mortality prediction tool in a cohort of hospitalized COVID-19 patients in Chile

IntroductionThe CALL score is a predictive tool for respiratory failure progression in COVID-19. Whether the CALL score is useful to predict short- and medium-term mortality in an unvaccinated population is unknown.Materials and methodsThis is a prospective cohort study in unvaccinated inpatients with a COVID-19 pneumonia diagnosis upon hospital admission. Patients were followed up for mortality at 28 days, 3, 6, and 12 months. Associations between CALL score and mortality were analyzed using logistic regression. The prediction performance was evaluated using the area under a receiver operating characteristic curve (AUROC).ResultsA total of 592 patients were included. On average, the CALL score was 9.25 (±2). Higher CALL scores were associated with increased mortality at 28 days [univariate: odds ratio (OR) 1.58 (95% CI, 1.34–1.88), p < 0.001; multivariate: OR 1.54 (95% CI, 1.26–1.87), p < 0.001] and 12 months [univariate OR 1.63 (95% CI, 1.38–1.93), p < 0.001; multivariate OR 1.63 (95% CI, 1.35–1.97), p < 0.001]. The prediction performance was good for both univariate [AUROC 0.739 (0.687–0.791) at 28 days and 0.869 (0.828–0.91) at 12 months] and multivariate models [AUROC 0.752 (0.704–0.8) at 28 days and 0.862 (0.82–0.905) at 12 months].ConclusionThe CALL score exhibits a good predictive capacity for short- and medium-term mortality in an unvaccinated population

Acceptance Ordering Scheduling Problem: The impact of an order-portfolio on a make-to-order firm’s profitability

Firms’ growth, the darling measure of investors, comes from higher revenues. Thus, sales and marketing departments make extreme efforts to accept as many customer orders as possible. Unfortunately, not all orders contribute equally to profits, and some orders may even reduce net profits. Thus, saying no (i.e., not accepting an order) may be a necessary condition for net profits growth. For understanding the impact of rejecting orders on profitability, we propose an order acceptance and scheduling problem (OAS). Although the OAS has extensively been studied in the literature, there is still some gap between these papers and real-life problems in industry. In an attempt to close that gap, the OAS we propose considers orders revenues, machines costs, holding costs and tardiness costs. We develop a mixed integer linear programming (MILP) model for solving this problem. Since the complexity of the problem makes it impossible for the MILP to solver large-scale instances, we also propose a metaheuristic algorithm. Numerical experiments show that the metaheuristic finds good quality solutions in short computational times. In the last part of the paper we confirm some managerial insights: higher holding and tardiness costs imply a lower acceptance of orders, forcing production has a concave negative impact on net profits, and accurately estimating costs is essential for good planning

Planificacion y mantencion de una maquina centrifuga continua K850 S, ubicada en Planta IANSA-CURICO

178 p.La constante renovación y los continuos avances tecnológicos hacen de las máquinas un punto de vital importancia, dentro del proceso productivo de una industria. En Chile, solo las grandes industrias han dado importancia a la mantención que sus plantas productivas mediante una mantención preventiva de ellas. En cambio, en la mediana y pequeña industria se ha adaptado la modalidad de reparar cuando las fallas se presentan, sin haberlas previsto. Debido a la gran importancia que una maquinaria cumple dentro de un proceso productivo industrial, el estudio de esta tesis comprenderá las maquinas centrifugas K850 S, por ser estas de gran importancia en la elaboración del azúcar. Las Máquinas centrífugas son empleadas mundialmente en las industrias azucareras, para se-parar los cristales de azúcar del siropo madre en una masa cocida. Esta preparación se realiza mediante el uso de la fuerza centrífuga, el Tes. elegido surgió debido a la posibilidad que tuvimos de ingresar a la Planta IANSA de Curico, la que se hallaba en pleno periodo de mantención. La tesis se desarrollara en cuatro capítulos, En el primer capítulo se analiza el proceso industrial Para la elaboración del azúcar y la función de la centrífuga dentro del proceso. En el segundo capítulo se da a conocer la planificación actual en Planta IANSA Curico, y se propone además una planificación de la mantención para la Planta. El Capítulo tercero consta de un estudio de la mantención en forma teórica, describiendo los diferentes tipos de mantención. Posteriormente se da a conocer la mantención que actualmente se realiza en la Planta a la Centrífuga F850 S, y además se dan a conocer las consideraciones que se deben tomar en cuenta para implementar un Plan de Mantención preventiva. También en este capítulo se propone un nuevo plan de mantenimiento para la Centrífuga K850 S. En el capítulo cuarto se hace un estudio económico de la mantención actual y mantención propuesta; se calcula también la depreciación de la maquina por dos métodos y se compara con los costos de mantención actual y propuestas

QED Fermions in a noisy magnetic field background

We consider the effects of a noisy magnetic field background over the fermion propagator in QED, as an approximation to the spatial inhomogeneities that would naturally arise in certain physical scenarios, such as heavy-ion collisions or the quark-gluon plasma in the early stages of the evolution of the Universe. We considered a classical, finite and uniform average magnetic field background $\langle\mathbf{B}(\mathbf{x})\rangle = \mathbf{B}$, subject to white-noise spatial fluctuations with auto-correlation of magnitude $\Delta_B$. By means of the Schwinger representation of the propagator in the average magnetic field as a reference system, we used the replica formalism to study the effects of the magnetic noise in the form of renormalized quasi-particle parameters, leading to an effective charge and an effective refraction index, that depend not only on the energy scale, as usual, but also on the magnitude of the noise $\Delta_B$ and the average field $\mathbf{B}$