Warm hilltop inflation

We study the low-temperature limit of warm inflation in a hilltop model. This limit remains valid up to the end of inflation, allowing an analytic description of the entire inflationary stage. In the weak dissipative regime, if the kinetic density of the inflaton dominates after inflation, low scale inflation is attained with Hubble scale as low as 1 GeV. In the strong dissipative regime, the model satisfies the observational requirements for the spectral index with a mild tuning of the model parameters, while also overcoming the $\eta$-problem of inflation. However, there is some danger of gravitino overproduction unless the particle content of the theory is large.Comment: 9 pages, 2 figure

Entorno de desarrollo de aplicaciones de vídeo-seguridad multicámara

El objetivo principal del proyecto ha sido elaborar una metodología de desarrollo de aplicaciones de vídeo-vigilancia que integren algoritmos de análisis de secuencias de vídeo. El entorno de desarrollo de las aplicaciones es una plataforma de procesado distribuido de vídeo, la cual permite la interconexión de los diferentes elementos que la componen. El proyecto también incluye mejoras en el funcionamiento de la plataforma y nuevas funcionalidades. Durante la realización del proyecto se han integrado dos algoritmos en el sistema para probar la metodología desarrollada. Para cada algoritmo se han cubierto las diferentes etapas de desarrollo de nidas a lo largo del proyecto, para nalmente obtener aplicaciones con interfaz grá ca que permiten procesar las imágenes obtenidas por los sistemas de captura de la plataforma y observar sus resultados.The main objective of this project has been to develop a methodology for the development of video surveillance applications that make use of video sequence analysis. The development environment of the applications is a framework for distributed video processing, which allows the connection between di erent elements that form part of the system. The project also includes upgrades in the operation of the framework as well as new functionalities. During the development of this project two algorithms have been integrated in the system in order to assess the developed methodology. For each algorithm all the steps of development have been covered to nally obtain applications with a graphic user interface that allow the processing of images obtained by the platform's capturing systems and observe its results

Atrial fibrillation dynamics and ionic block effects in six heterogeneous human 3D virtual atria with distinct repolarization dynamics

Atrial fibrillation (AF) usually manifests as reentrant circuits propagating through the whole atria creating chaotic activation patterns. Little is yet known about how differences in electrophysiological and ionic properties between patients modulate reentrant patterns in AF. The goal of this study is to quantify how variability in action potential duration (APD) at different stages of repolarization determines AF dynamics and their modulation by ionic block using a set of virtual whole-atria human models. Six human whole-atria models are constructed based on the same anatomical structure and fiber orientation, but with different electrophysiological phenotypes. Membrane kinetics for each whole-atria model are selected with distinct APD characteristics at 20, 50, and 90% repolarization, from an experimentally calibrated population of human atrial action potential models, including AF remodeling and acetylcholine parasympathetic effects. Our simulations show that in all whole-atria models, reentrant circuits tend to organize around the pulmonary veins and the right atrial appendage, thus leading to higher dominant frequency (DF) and more organized activation in the left atrium than in the right atrium. Differences in APD in all phases of repolarization (not only APD90) yielded quantitative differences in fibrillation patterns with long APD associated with slower and more regular dynamics. Long APD50 and APD20 were associated with increased interatrial conduction block and interatrial differences in DF and organization index, creating reentry instability and self-termination in some cases. Specific inhibitions of IK1, INaK, or INa reduce DF and organization of the arrhythmia by enlarging wave meandering, reducing the number of secondary wavelets, and promoting interatrial block in all six virtual patients, especially for the phenotypes with short APD at 20, 50, and/or 90% repolarization. This suggests that therapies aiming at prolonging the early phase of repolarization might constitute effective antiarrhythmic strategies for the pharmacological management of AF. In summary, simulations report significant differences in atrial fibrillatory dynamics resulting from differences in APD at all phases of repolarization

Origins, Concept and Developments of Intellectual Capital in the Knowledge Economy: Intellectus Model and its Main Applications

En el entorno socio-económico actual de la Economía del Conocimiento, la principal fuente de ventaja competitiva sostenible de las organizaciones reside fundamentalmente en sus activos de naturaleza intangible, reflejados en su Capital Intelectual. En la última década del siglo XX, comenzó a desarrollarse la principal literatura de Dirección del Conocimiento y Capital Intelectual en las organizaciones, y con ella surgieron los primeros esfuerzos de evaluación de este último concepto. El presente trabajo muestra, en primer lugar, el origen, justificación y desarrollo del Capital Intelectual, para pasar seguidamente a destacar los principales modelos. A continuación, se analiza el concepto de Capital Intelectual, y seguidamente las principales aplicaciones y experiencias desarrolladas de uno de los modelos presentados, el Modelo Intellectus. Finalmente, se recogen las conclusiones del trabajo y posibles líneas de investigación a desarrollar sobre el tema.The main source of competitive sustainable advantage, in the current socio-economic environment of the Knowledge Economy, resides basically in the Intellectual Capital. The main literature on Knowledge Management and Intellectual Capital was developed in the last decade of the 20th century, giving rise to the initial attempts for evaluating the latter concept. This paper examines firstly the origin and development of the Intellectual Capital and discusses the chief existing models. Then, the concept of Intellectual Capital is analysed together with the main applications and implementations of a particularly relevant model, the Intellects model. Finally, some conclusions and future research extensions are presented

Análisis de costos de la generación de energía eléctrica mediante fuentes renovables en el sistema eléctrico colombiano

In this paper a cost analysis by means the Total Cost Model is performed, in order to valuate the economic impact involved in the integration of renewable energies in the Colombian electric system, considering that its infrastructure is based on the water resource. The high potential of the country to implement renewable energy, particularly wind and biomass, explains the need to propose different scenarios for electricity generation and makes analysis of their capital, fixed, variable and external costs taking into account the experience (learning curve). Conclusions about the feasibility of implementing new technologies for the energy future of the country are reached.En este trabajo se realiza un análisis financiero mediante el modelo de costo total, con el fin de valorar el impacto económico que implica la integración de energías renovables en el sistema eléctrico colombiano, teniendo en cuenta que su infraestructura actual se basa en el recurso hídrico. El alto potencial del país para la implementación de energías renovables, específicamente la eólica y biomasa, explica la necesidad de proponer diferentes escenarios de generación eléctrica y realizar un análisis a los costos de capital, fijos, variables y externos teniendo en cuenta la experiencia y, por ende, la curva de aprendizaje. Se alcanzan conclusiones acerca de la viabilidad para la implementación de nuevas tecnologías para el futuro energético del país

Diatom identification including life cycle stages through morphological and texture descriptors

Diatoms are unicellular algae present almost wherever there is water. Diatom identification has many applications in different fields of study, such as ecology, forensic science, etc. In environmental studies, algae can be used as a natural water quality indicator. The diatom life cycle consists of the set of stages that pass through the successive generations of each species from the initial to the senescent cells. Life cycle modeling is a complex process since in general the distribution of the parameter vectors that represent the variations that occur in this process is non-linear and of high dimensionality. In this paper, we propose to characterize the diatom life cycle by the main features that change during the algae life cycle, mainly the contour shape and the texture. Elliptical Fourier Descriptors (EFD) are used to describe the diatom contour while phase congruency and Gabor filters describe the inner ornamentation of the algae. The proposed method has been tested with a small algae dataset (eight different classes and more than 50 samples per type) using supervised and non-supervised classification techniques obtaining accuracy results up to 99% and 98% respectively

Experimental analysis of connectivity management in mobile operating systems

We are immerse in a world that becomes more and more mobile every day, with ubiquitous connectivity and increasing demand for mobile services. Current mobile terminals support several access technologies, enabling users to gain connectivity in a plethora of scenarios and favoring their mobility. However, the management of network connectivity using multiple interfaces is still starting to be deployed. The lack of smart connectivity management in multi interface devices forces applications to be explicitly aware of the variations in the connectivity state (changes in active interface, simultaneous access from several interfaces, etc.). In this paper, we analyze the present state of the connection management and handover capabilities in the three major mobile operating systems (OSes): Android, iOS and Windows. To this aim, we conduct a thorough experimental study on the connectivity management of each operating system, including several versions of the OS on different mobile terminals, analyzing the differences and similarities between them. Moreover, in order to assess how mobility is handled and how this can affect the final user, we perform an exhaustive experimental analysis on application behavior in intra- and inter-technology handover. Based on this experience, we identify open issues in the smartphone connectivity management policies and implementations, highlighting easy to deploy yet unimplemented improvements, as well as potential integration of mobility protocols.This work has been partially supported by the European Community through the CROWD project, FP7-ICT-318115.Publicad

Atrial Fibrillation Dynamics and Ionic Block Effects in Six Heterogeneous Human 3D Virtual Atria with Distinct Repolarization Dynamics

Atrial fibrillation (AF) usually manifests as reentrant circuits propagating through the whole atria creating chaotic activation patterns. Little is yet known about how differences in electrophysiological and ionic properties between patients modulate reentrant patterns in AF. The goal of this study is to quantify how variability in action potential duration (APD) at different stages of repolarization determines AF dynamics and their modulation by ionic block using a set of virtual whole-atria human models. Six human whole-atria models are constructed based on the same anatomical structure and fiber orientation, but with different electrophysiological phenotypes. Membrane kinetics for each whole-atria model are selected with distinct APD characteristics at 20, 50, and 90% repolarization, from an experimentally calibrated population of human atrial action potential models, including AF remodeling and acetylcholine parasympathetic effects. Our simulations show that in all whole-atria models, reentrant circuits tend to organize around the pulmonary veins and the right atrial appendage, thus leading to higher dominant frequency (DF) and more organized activation in the left atrium than in the right atrium. Differences in APD in all phases of repolarization (not only APD90) yielded quantitative differences in fibrillation patterns with long APD associated with slower and more regular dynamics. Long APD50 and APD20 were associated with increased interatrial conduction block and interatrial differences in DF and organization index, creating reentry instability and self-termination in some cases. Specific inhibitions of IK1, INaK, or INa reduce DF and organization of the arrhythmia by enlarging wave meandering, reducing the number of secondary wavelets, and promoting interatrial block in all six virtual patients, especially for the phenotypes with short APD at 20, 50, and/or 90% repolarization. This suggests that therapies aiming at prolonging the early phase of repolarization might constitute effective antiarrhythmic strategies for the pharmacological management of AF. In summary, simulations report significant differences in atrial fibrillatory dynamics resulting from differences in APD at all phases of repolarization

A low-cost automated digital microscopy platform for automatic identification of diatoms

This article belongs to the Special Issue Advanced Intelligent Imaging Technology Ⅱ[EN] Currently, microalgae (i.e., diatoms) constitute a generally accepted bioindicator of water quality and therefore provide an index of the status of biological ecosystems. Diatom detection for specimen counting and sample classification are two difficult time-consuming tasks for the few existing expert diatomists. To mitigate this challenge, in this work, we propose a fully operative low-cost automated microscope, integrating algorithms for: (1) stage and focus control, (2) image acquisition (slide scanning, stitching, contrast enhancement), and (3) diatom detection and a prospective specimen classification (among 80 taxa). Deep learning algorithms have been applied to overcome the difficult selection of image descriptors imposed by classical machine learning strategies. With respect to the mentioned strategies, the best results were obtained by deep neural networks with a maximum precision of 86% (with the YOLO network) for detection and 99.51% for classification, among 80 different species (with the AlexNet network). All the developed operational modules are integrated and controlled by the user from the developed graphical user interface running in the main controller. With the developed operative platform, it is noteworthy that this work provides a quite useful toolbox for phycologists in their daily challenging tasks to identify and classify diatomsSIThis research was funded by the Spanish Government under the AQUALITAS-RETOS project with Ref. CTM2014-51907-C2-2-R-MINEC

Diseño e implementación de un sistema automático de core de camisas para cilindros neumáticos para la empresa IMATIC S.A.

Se ejecutó el diseño e Implementación de un sistema automático para el corte de tubo de aluminio (camisa), utilizado para la fabricación de cilindros neumáticos, con el propósito de disminuir el tiempo del proceso y evitar accidentes de tipo laboral, para la empresa IMATIC S.A de Quito - Ecuador. Para la implementación del sistema se utilizó PLC como controlador, pantalla táctil como Interfaz Humano - Maquina (HMI), equipo portátil para la configuración, elementos neumáticos para control de aire comprimido, y accesorios de conexión eléctrica y neumática. Se utilizó método GRAFCET para obtener una representación gráfica de los procesos del sistema mediante bloques, cuyo comportamiento se define por variables de entrada - salida. Para establecer la secuencia de funcionamiento, se analizaron las condiciones generales, se ubicaron los bloques en orden de ejecución y se interconectaron por medio de transiciones, condiciones que fueron programadas en el PLC con el software TIA Portal, al igual que el HMI en la pantalla táctil. La interconexión entre los sistemas electroneumático y de control se realizó con cableado en el tablero principal, en tanto que los elementos mecánicos se acoplaron con tubería de aire comprimido. El nuevo sistema fue sometido a prueba, obteniéndose un 40% de reducción en el tiempo de corte y ensamblaje de cilindros de aluminio en comparación al método convencional con el que se trabajaba, logrando además gran exactitud. Se recomienda implementar un programa de mantenimiento para optimizar el sistema