Optimizing mobile applications by exploiting variability models at runtime

El servicio de reconfiguración dinámica genera y despliega configuraciones de la aplicación optimizadas para el contexto de la ejecución. Para la generación eficiente de estas configuraciones se han definido los algoritmos genéticos DAGAME (mono-objetivo) y MO-DAGAME (multi-objetivo). Ambos algoritmos han sido evaluados, obteniendo buenos resultados con respecto al tiempo de ejecución y a la calidad de las configuraciones generadas. Fecha de lectura de Tesis Doctoral: 18 de diciembre 2018.Los teléfonos móviles inteligentes son una herramienta indispensable en nuestra vida cotidiana. Son dispositivos con los que podemos ejecutar aplicaciones y tareas complejas en cualquier lugar y en cualquier momento. Estas aplicaciones están fuertemente relacionadas con su contexto (e.g., localización, recursos disponibles, etc.) y los requisitos del usuario cambian cuando lo hace el contexto en el que se ejecutan. Por lo tanto, desarrollar aplicaciones que se adaptan al contexto es fundamental para satisfacer dichos requisitos y, para lograrlo, es necesario proporcionar mecanismos de reconfiguración dinámica. Un enfoque ampliamente aceptado para gestionar la variabilidad de las aplicaciones en tiempo de ejecución son las Líneas de Producto Software Dinámicas (DSPLs). Por otro lado, otro paradigma ampliamente aceptado en la comunidad de los sistemas distributidos es el de la Computación Autónoma (CA), cuyo principal objetivo es dotar a los sistemas distribuidos de capacidades de auto-gestión. Esta tesis explora la aplicación de las DSPLs y la CA al desarrollo de aplicaciones para dispositivos móviles que pueden ser reconfiguradas en tiempo de ejecución en función de su contexto. Sus contribuciones cubren tanto el diseño de la DSPL como el desarrollo de mecanismos de reconfiguración dinámica. Con respecto al diseño de la DSPL, se han propuesto dos alternativas diferentes para la especificación de la arquitectura software y la variabilidad. Por un lado, un mecanismo basado en el uso de perfiles UML y herramientas para modelos de características. Por otro lado, un mecanismo basado en el uso del lenguaje CVL para el modelado de la variabilidad. Para la adaptación de las aplicaciones en tiempo de ejecución se ha definido un middleware que incluye servicios de monitorización del contexto y de reconfiguración dinámica

Run-time Support to Manage Architectural Variability Speci ed with CVL

The execution context in which pervasive systems or mobile computing run changes continuously. Hence, applications for these systems should be adapted at run-time according to the current context. In order to implement a context-aware dynamic reconfiguration service, most approaches usually require to model at design-time both the list of all possible configurations and the plans to switch among them. In this paper we present an alternative approach for the automatic run-time generation of application configurations and the reconfiguration plans. The generated configurations are optimal regarding di erent criteria, such as functionality or resource consumption (e.g. battery or memory). This is achieved by: (1) modelling architectural variability at design-time using Common Variability Language (CVL), and (2) using a genetic algorithm that finds at run-time nearly-optimal configurations using the information provided by the variability model. We also specify a case study and we use it to evaluate our approach, showing that it is efficient and suitable for devices with scarce resources.Campus de Excelencia Internacional Andalucia Tech y proyectos de investigación TIN2008-01942, P09-TIC-5231 and INTER-TRUST FP7-317731

Lattice preamorphization by ion irradiation: Fluence dependence of the electronic stopping power threshold for amorphization

A thermal-spike model has been applied to characterize the damage structure of the latent tracks generated by high-energy ion irradiations on LiNb O3 through electron excitation mechanisms. It applies to ions having electronic stopping powers both below and above the threshold value for lattice amorphization. The model allows to estimate the defect concentrations in the heavily damaged (preamorphized) regions that have not reached the threshold for amorphization. They include the halo and tail surrounding the core of a latent track. The existence of the preamorphized regions accounts for a synergy between successive irradiations and predicts a dependence of the amorphization threshold on previous irradiation fluence. The predicted dependence is in accordance with irradiation experiments using N (4.53 MeV), O (5.00 MeV), F (5.13 MeV), and Si (5 and 7.5 MeV). For electronic stopping powers above the threshold value the model describes the generation of homogeneous amorphous layers and predicts the propagation of the amorphization front with fluence. A theoretical expression, describing this propagation, has been obtained that is in reasonable agreement with silicon irradiation experiments at 5 and 7.5 MeV. The accordance is improved by including in a simple phenomenological way the velocity effect on the threshold. At the highest fluences (or depths) a significant discrepancy appears that may be attributed to the contribution of the nuclear collision damage. © 2005 American Institute of Physics.Peer Reviewe

Run-time Adaptation of Mobile Applications using Genetic Algorithms

Mobile applications run in environments where the context is continuously changing. Therefore, it is necessary to provide support for the run-time adaptation of these applications. This support is usually achieved by middleware platforms that offer a context-aware dynamic reconfiguration service. However, the main shortcoming of existing approaches is that both the list of possible configurations and the plans to adapt the application to a new configuration are usually specified at design-time. In this paper we present an approach that allows the automatic generation at run-time of application configurations and of reconfiguration plans. Moreover, the generated configurations are optimal regarding the provided functionality and, more importantly, without exceeding the available resources (e.g. battery). This is performed by: (1) having the information about the application variability available at runtime using feature models, and (2) using an genetic algorithm that allows generating an optimal configuration at runtime. We have specified a case study and evaluated our approach, and the results show that it is efficient enough as to be used on mobile devices without introducing an excessive overhead.Campus de Excelencia Andalucía Tech y Proyectos de investigación TIN2008-01942, P09-TIC-5231 y INTER-TRUST FP7-317731

Optical determination of three-dimensional nanotrack profiles generated by single swift-heavy ion impacts in lithium niobate

Three-dimensional (3D) profiles of single nanotracks generated by a low impact density of Cl ions at 46 MeV have been determined by optical methods, using an effective-medium approach. The buried location of the maximum stopping power induces a surface optical waveguiding layer even at ultralow fluences (1011-1013 at./cm2) that allows to obtain the effective refractive index profiles (from dark-mode measurements). Combining the optical information with Rutherford backscattering spectroscopy/channeling experiments, the existence of a surrounding defective halo around the amorphous track core has been ascertained. The 3D profile of the halo has also been determined. © 2006 American Institute of Physics.Peer Reviewe

Optical determination of three-dimensional nanotrack profiles generated by single swift-heavy ion impacts in lithium niobate

Three-dimensional (3D) profiles of single nanotracks generated by a low impact density of Cl ions at 46 MeV have been determined by optical methods, using an effective-medium approach. The buried location of the maximum stopping power induces a surface optical waveguiding layer even at ultralow fluences (1011-1013 at./cm2) that allows to obtain the effective refractive index profiles (from dark-mode measurements). Combining the optical information with Rutherford backscattering spectroscopy/channeling experiments, the existence of a surrounding defective halo around the amorphous track core has been ascertained. The 3D profile of the halo has also been determined. © 2006 American Institute of Physics.Peer Reviewe

An energy management system design using fuzzy logic control: smoothing the grid power profile of a residential electro-thermal microgrid

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This work deals with the design of a Fuzzy Logic Control (FLC) based Energy Management System (EMS) for smoothing the grid power profile of a grid-connected electro-thermal microgrid. The case study aims to design an Energy Management System (EMS) to reduce the impact on the grid power when renewable energy sources are incorporated to pre-existing grid-connected household appliances. The scenario considers a residential microgrid comprising photovoltaic and wind generators, flat-plate collectors, electric and thermal loads and electrical and thermal energy storage systems and assumes that neither renewable generation nor the electrical and thermal load demands are controllable. The EMS is built through two low-complexity FLC blocks of only 25 rules each. The first one is in charge of smoothing the power profile exchanged with the grid, whereas the second FLC block drives the power of the Electrical Water Heater (EWH). The EMS uses the forecast of the electrical and thermal power balance between generation and consumption to predict the microgrid behavior, for each 15-minute interval, over the next 12 hours. Simulations results, using real one-year measured data show that the proposed EMS design achieves 11.4% reduction of the maximum power absorbed from the grid and an outstanding reduction of the grid power profile ramp-rates when compared with other state-of-the-art studies.Peer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantPostprint (published version

Psycho-emotional disorders as incoming risk factors for myocardial infarction with non-obstructive coronary arteries

  Background: There is an emerging field underlying the myocardial infarction (MI) with non-obstruc­tive coronary arteries (MINOCA). The aim of this study was to evaluate the impact of psycho-emotional disorders and social habits in MINOCA patients. Methods: The study included 95 consecutive patients diagnosed of MINOCA and 178 patients with MI and obstructive lesions. MINOCA patients were included when they fulfilled the three main criteria: accomplishment of the Third Universal Definition of Myocardial Infarction, absence of obstructive coronary arteries and no clinically overt specific cause for the acute presentation. Results: MINOCA patients had a higher frequency of previous psychiatric illnesses than the obstructive coronary arteries group (29.7% vs. 12.9%, p = 0.001). MINOCA patients recognized emotional stress in 75.7% of the cases, while only 32.1% of the obstructive related group did (p < 0.001). The relation­ship remained after excluding takotsubo syndrome from the analysis (26 cases, 27.4%): psychiatric diseases (27.9% vs. 12.9%, p < 0.01) and recognition of emotional stress (70.8% vs. 32.1%, p < 0.001). Social habits which could act as stress modulating showed no significant relation with MINOCA. Conclusions: Psycho-emotional disorders are related to MINOCA and they could act as risk fac­tor. This relationship is maintained after excluding takotsubo from the analysis. (Cardiol J 2018; 25, 1: 24–31

Molecular method for the characterization of Coxiella burnetii from clinical and environmental samples: variability of genotypes in Spain

BACKGROUND: Coxiella burnetii is a highly clonal microorganism which is difficult to culture, requiring BSL3 conditions for its propagation. This leads to a scarce availability of isolates worldwide. On the other hand, published methods of characterization have delineated up to 8 different genomic groups and 36 genotypes. However, all these methodologies, with the exception of one that exhibited limited discriminatory power (3 genotypes), rely on performing between 10 and 20 PCR amplifications or sequencing long fragments of DNA, which make their direct application to clinical samples impracticable and leads to a scarce accessibility of data on the circulation of C. burnetii genotypes. RESULTS: To assess the variability of this organism in Spain, we have developed a novel method that consists of a multiplex (8 targets) PCR and hybridization with specific probes that reproduce the previous classification of this organism into 8 genomic groups, and up to 16 genotypes. It allows for a direct characterization from clinical and environmental samples in a single run, which will help in the study of the different genotypes circulating in wild and domestic cycles as well as from sporadic human cases and outbreaks. The method has been validated with reference isolates. A high variability of C. burnetii has been found in Spain among 90 samples tested, detecting 10 different genotypes, being those adaA negative associated with acute Q fever cases presenting as fever of intermediate duration with liver involvement and with chronic cases. Genotypes infecting humans are also found in sheep, goats, rats, wild boar and ticks, and the only genotype found in cattle has never been found among our clinical samples. CONCLUSIONS: This newly developed methodology has permitted to demonstrate that C. burnetii is highly variable in Spain. With the data presented here, cattle seem not to participate in the transmission of C. burnetii to humans in the samples studied, while sheep, goats, wild boar, rats and ticks share genotypes with the human population

Clinical characteristics and prognosis of myocardial infarction with non-obstructive coronary arteries (MINOCA): A prospective single-center study

Background: A definition of myocardial infarction with non-obstructive coronary arteries (MINOCA) was published by European Society of Cardiology in 2016. The aim of this study is to analyze the clinical profile and prognosis of these patients in a prospective single-center study and compare it with the literature data. Methods: During a 3-year period, information from every consecutive MINOCA patient was gathered (n = 109). It was then compared with 412 contemporaneous patients with myocardial infarction and obstructive coronary arteries (MIOCA). Univariate and multivariate analyses were performed. Prognosis analysis was adjusted by age and cardiovascular risk factors (CVRF). Results: MINOCA represented 16.9% of the total of patients admitted for myocardial infarction. Compared with MIOCA, they had more psychosocial disorders (22.9% vs. 10.7%; p < 0.01) and more pro-inflammatory conditions (34.9% vs. 14.0%; p < 0.01). Atrial fibrillation was twice as frequent in MINOCA (14.7% vs. 7.3%; p = 0.016). Predictors of MINOCA were as follows: female gender, absence of diabetes, absence of tobacco use, tachycardia, troponin above 10 times the 99th percentile, and pro-inflammatory conditions. Median follow-up was 17.3 ± 9.3 months. Major adverse cardiovascular events (MACE; a composite of a recurrence of acute myocardial infarction, transient ischemic attack/stroke, or death from cardiovascular cause and death from any cause) occurred in 10.8% of the MINOCA group as compared with 10.7% in the MIOCA group (hazard ratio [HR] 1.19, 95% confidence interval [CI] 0.58–2.45; p = 0.645). Cardiovascular re-admission rates were higher in the MINOCA group: 19.8% vs. 13.9% (HR 1.85; CI 1.06–3.21; p = 0.030). Conclusions: The frequency of MINOCA is high, with fewer CVRF, and it is linked to atrial fibrillation, psychosocial disorders, and pro-inflammatory conditions. Mid-term prognosis is worse than previously thought, with a similar proportion of MACE as compared to MIOCA, and even a higher rate of cardiovascular re-admissions