Nuevas técnicas de inyección de fallos en sistemas embebidos mediante el uso de modelos virtuales descritos en el nivel de transacción

Mejor software y más rápido. Este es el desafío que se deriva de la necesidad de construir sistemas cada vez más inteligentes. En cualquier diseño embebido actual, el software es un componente fundamental que dota al sistema de una alta capacidad de configuración, gran número de funcionalidades y elasticidad en el comportamiento del sistema en situaciones excepcionales. Si además el desarrollo del conjunto hardware/software integrado en un System on Chip (SoC), forma parte de un sistema de control crítico donde se deben tener en cuenta requisitos de tolerancia a fallos, la verificación exhaustiva de los mismos consume un porcentaje cada vez más importante de los recursos totales dedicados al desarrollo y puesta en funcionamiento del sistema. En este contexto, el uso de metodologías clásicas de codiseño y coverificación es completamente ineficiente, siendo necesario el uso de nuevas tecnologías y herramientas para el desarrollo y verificación tempranos del software embebido. Entre ellas se puede incluir la propuesta en este trabajo de tesis, la cual aborda el problema mediante el uso de modelos ejecutables del hardware definidos en el nivel de transacción. Debido a los estrictos requisitos de robustez que imperan en el desarrollo de software espacial, es necesario llevar a cabo tareas de verificación en etapas muy tempranas del desarrollo para asegurar que los mecanismos de tolerancia a fallos, avanzados en la especificación del sistema, funcionan adecuadamente. De forma general, es deseable que estas tareas se realicen en paralelo con el desarrollo hardware, anticipando problemas o errores existentes en la especificación del sistema. Además, la verificación completa de los mecanismos de excepción implementados en el software, puede ser imposible de realizar en hardware real ya que los escenarios de fallo deben ser artificial y sistemáticamente generados mediante técnicas de inyección de fallos que permitan realizar campañas de inyección controlables, observables y reproducibles. En esta tesis se describe la investigación, desarrollo y uso de una plataforma virtual denominada "Leon2ViP", con capacidad de inyección de fallos y basada en interfaces SystemC/TLM2 para el desarrollo temprano y verificación de software embebido en el marco del proyecto Solar Orbiter. De esta forma ha sido posible ejecutar y probar exactamente el mismo código binario a ejecutar en el hardware real, pero en un entorno más controlable y determinista. Ello permite la realización de campañas de inyección de fallos muy focalizadas que no serían posible de otra manera. El uso de "\Leon2ViP" ha significado una mejora significante, en términos de coste y tiempo, en el desarrollo y verificación del software de arranque de la unidad de control del instrumento (ICU) del detector de partículas energéticas (EPD) embarcado en Solar Orbiter

Residential wireless interfaces virtualization: a feasibility study

This paper investigates the possibility of virtualizing and distributing the functionality that runs on top of residential wireless communications. Specifically, we propose, describe and test a solution that transports USB communications to remote locations, for scenarios in which the in-home wireless interfaces are consumed at the server side through this type of general-purpose and widely used interfaces. We frame this study in a general architecture by which Software Defined Networking (SDN) and Network Functions Virtualization (NFV) bring economies of scale, flexibility and programmability to residential Internet of Things (IoT) environments. As a result of our tests, we prove the feasibility of the remote presence of the IoT systems through the Universal Serial Bus (USB) tunnels, and we obtain approximate bandwidth measurements that serve as a hint on the type of services that can be offloaded to the cloud. For those functionalities that would need more bandwidth, we propose to embed a lightweight virtualization environment in home and to execute in it part of the virtualized components, something that is in line with the recent fog computing approaches

Up2B2: Playing English grammar games at the B2 level

The study presented herein is framed within the Mobile Assisted Language Learning (MALL) approach and presents the results from the use of an original mobile app, developed by the research team, on the part of 73 students. The app prototype consists of multiple choice questions and answers that assess varied aspects of the grammar, vocabulary and use of English at level B2 according to the Common European Framework of Reference for Languages (CEFRL). The application presents motivating gamification components that aim at enhancing students’ participation and regular use of the game. Some of these gamification features are response time, use of competition and training tests, and a score ranking based on nicknames. The study uses different indexes in order to describe the use of the platform and qualitative and quantitative indicators to reach positive conclusions related to students’ increased motivation and improvement in their grammar and vocabulary competence levels

Aprendizaje asistido por dispositivos móviles: UP2B2

Este trabajo se enmarca en el enfoque denominado Mobile Assisted Language Learning (MALL) y presenta un prototipo de juego de preguntas y respuestas de opción múltiple que revisa la gramática, el vocabulario y el uso de la lengua inglesa del nivel B2 (Marco Común Europeo de Referencia para las Lenguas-MCERL). La aplicación se caracteriza por presentar una componente de gamificación cuyo objetivo es motivar a los estudiantes a que la usen mediante un sistema de puntuación que los sitúa en un ranking global y que considera tanto los aciertos de cada uno como el tiempo en completar los tests. Se definen distintos índices para la monitorización de la plataforma e indicadores tanto de carácter cualitativo como cuantitativo para la medida de los resultados. ABSTRACT This work is framed within the approach called Mobile Assisted Language Learning (MALL) and presents a game prototype consisting of multiple choice questions and answers that assess the grammar, vocabulary and the use of the English language at level B2 according to the Common European Framework of Reference for Languages. The application is characterized by a strong gamification component that aims to motivate the students using it. Therefore, response time, correct answers and a ranking with the punctuation centre the most prominent aspects related to its playability. Different indexes are defined for the monitoring of the platform as well as qualitative and quantitative indicators for the study of the results

Pervasive surveillance-agent system based on wireless sensor networks: design and deployment

Nowadays, proliferation of embedded systems is enhancing the possibilities of gathering information by using wireless sensor networks (WSNs). Flexibility and ease of installation make these kinds of pervasive networks suitable for security and surveillance environments. Moreover, the risk for humans to be exposed to these functions is minimized when using these networks. In this paper, a virtual perimeter surveillance agent, which has been designed to detect any person crossing an invisible barrier around a marked perimeter and send an alarm notification to the security staff, is presented. This agent works in a state of 'low power consumption' until there is a crossing on the perimeter. In our approach, the 'intelligence' of the agent has been distributed by using mobile nodes in order to discern the cause of the event of presence. This feature contributes to saving both processing resources and power consumption since the required code that detects presence is the only system installed. The research work described in this paper illustrates our experience in the development of a surveillance system using WNSs for a practical application as well as its evaluation in real-world deployments. This mechanism plays an important role in providing confidence in ensuring safety to our environment

Memory management unit for hardware-assisted dynamic relocation in on-board satellite systems

Satellite on-board systems spend their lives in hostile environments, where radiation can cause critical hardware failures. One of the most radiation-sensitive elements is memory. The so-called single event effects (SEEs) can corrupt or even irretrievably damage the cells that store the data and program instructions. When one of these cells is corrupted, the program must not use it again during execution. In order to avoid rebuilding and uploading the code, a memory management unit can be used to transparently relocate the program to an error-free memory region. This article presents the design and implementation of a memory management unit that allows the dynamic relocation of on-board software. This unit provides a hardware mechanism that allows the automatic relocation of sections of code or data at run-time, only requiring software intervention for initialization and configuration. The unit has been implemented on the LEON architecture, a reference for the European Space Agency (ESA) missions. The proposed solution has been validated using the boot and application software (ASW) of the instrument control unit of the Energetic Particle Detector of the Solar Orbiter Mission as a base. Processor synthesis on different FPGAs has shown resource usage and power consumption similar to that of a conventional memory management unit. The results vary between ± 1?15% in resource usage and ± 1?7% in power consumption, depending on the number of inputs assigned to the unit and the FPGA used. When comparing performance, both the proposed and conventional memory management units show the same results.Universidad de Alcal

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Residential wireless interfaces virtualization: a feasibility study

This paper investigates the possibility of virtualizing and distributing the functionality that runs on top of residential wireless communications. Specifically, we propose, describe and test a solution that transports USB communications to remote locations, for scenarios in which the in-home wireless interfaces are consumed at the server side through this type of general-purpose and widely used interfaces. We frame this study in a general architecture by which Software Defined Networking (SDN) and Network Functions Virtualization (NFV) bring economies of scale, flexibility and programmability to residential Internet of Things (IoT) environments. As a result of our tests, we prove the feasibility of the remote presence of the IoT systems through the Universal Serial Bus (USB) tunnels, and we obtain approximate bandwidth measurements that serve as a hint on the type of services that can be offloaded to the cloud. For those functionalities that would need more bandwidth, we propose to embed a lightweight virtualization environment in home and to execute in it part of the virtualized components, something that is in line with the recent fog computing approaches

Everolimus for cardiac rhabdomyomas in children with tuberous sclerosis. The ORACLE study protocol (everOlimus for caRdiac rhAbdomyomas in tuberous sCLErosis): a randomised, multicentre, placebo-controlled, double-blind phase II trial

Introduction: Tuberous sclerosis complex is a rare genetic disorder leading to the growth of hamartomas in multiple organs, including cardiac rhabdomyomas. Children with symptomatic cardiac rhabdomyoma require frequent admissions to intensive care units, have major complications, namely, arrhythmias, cardiac outflow tract obstruction and heart failure, affecting the quality of life and taking on high healthcare cost. Currently, there is no standard pharmacological treatment for this condition, and the management includes a conservative approach and supportive care. Everolimus has shown positive effects on subependymal giant cell astrocytomas, renal angiomyolipoma and refractory seizures associated with tuberous sclerosis complex. However, evidence supporting efficacy in symptomatic cardiac rhabdomyoma is limited to case reports. The ORACLE trial is the first randomised clinical trial assessing the efficacy of everolimus as a specific therapy for symptomatic cardiac rhabdomyoma. Methods: ORACLE is a phase II, prospective, randomised, placebo-controlled, double-blind, multicentre protocol trial. A total of 40 children with symptomatic cardiac rhabdomyoma secondary to tuberous sclerosis complex will be randomised to receive oral everolimus or placebo for 3 months. The primary outcome is 50% or more reduction in the tumour size related to baseline. As secondary outcomes we include the presence of arrhythmias, pericardial effusion, intracardiac obstruction, adverse events, progression of tumour reduction and effect on heart failure. Conclusions: ORACLE protocol addresses a relevant unmet need in children with tuberous sclerosis complex and cardiac rhabdomyoma. The results of the trial will potentially support the first evidence-based therapy for this condition