Antonio da Silva

• Doctor of Engineering
• University of Alcalá

The burgeoning interest within the space community in digital beamforming is largely attributable to the superior flexibility that satellites with active antenna systems offer for a wide range of applications, notably in communication services. This paper delves into the analysis and practical implementation of a Digital Beamforming and Digital Dow...

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 corru...

Space domain systems must go through different types of ground testing. For system-level black-box functional testing, ground support equipment is built ad hoc, customized for each different mission. Building any of this specific equipment involves considerable engineering effort that can be diluted using techniques that allow reusing configuration...

In recent decades, mixed-criticality systems have been widely adopted to reduce the complexity and development times of real-time critical applications. In these systems, applications run on a separation kernel hypervisor, a software element that controls the execution of the different operating systems, providing a virtualized environment and ensu...

The development process of on-board software applications can benefit from model-driven engineering techniques. Model validation and model transformations can be applied to drive the activities of specification, requirements definition, and system-level validation and verification according to the space software engineering standards ECSS-E-ST-40 a...

Multicore hardware platforms are being incorporated into spacecraft on-board systems to achieve faster and more efficient data processing. However, such systems lead to increased complexity in software development and represent a considerable challenge, especially concerning the runtime verification of fault-tolerance requirements. To address the e...

Real-time systems are characterised by the fact that they have to meet a set of both functional and temporal requirements. Processor architectures have a significant impact on the predictability of software execution times and can add different sources of indeterminism depending on the features provided. The LEON processor family is the reference p...

Code instrumentation enables the observability of an embedded software system during its execution. A usage example of code instrumentation is the estimation of “worst-case execution time” using hybrid analysis. This analysis combines static code analysis with measurements of the execution time on the deployment platform. Static analysis of source...

In space missions, boot software is in charge of the initialisation sequence of flight computers. The processor module in which it runs has a high tolerance to radiation, although not all devices have the same tolerance level. A boot software design capable of recovering from errors in the most vulnerable devices shall provide greater system reliab...

In this work a platform-aware model-driven engineering process for building component-based embedded software systems using annotated analysis models is described. The process is supported by a framework, called MICOBS, that allows working with different component technologies and integrating different tools that, independently of the component tec...

In this day and age, successful embedded critical software needs agile and continuous development and testing procedures. This paper presents the overall testing and code coverage metrics obtained during the unit testing procedure carried out to verify the correctness of the boot software that will run in the Instrument Control Unit (ICU) of the En...

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 u...

Since the word "app" was named "Word of the Year" by the American Dialect Society in 2010, the demand for education in mobile technologies has never been greater. This paper describes the experience gained while teaching mobile apps development as a subject in a Computer Science engineering curriculum for three academic years. We provide a descript...

Resumen-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 po...

paper presents the design of a SystemC transaction level modelling wrapping library that can be used for the assertion of system properties, protocol compliance, or fault injection. The library uses C++ virtual table hooks as a dynamic binary instrumentation technique to inline wrappers in the TLM2 transaction path. This technique can be applied af...

It is said that even the longest journey begins with the first step. This is also true for application software. When the power is switched on, computer systems execute an initial set of operations that usually perform memory tests and load the final runtime environment. This paper describes the Single Event Effects (SEEs) requirements verification...

ESA’s medium-class Solar Orbiter mission is conceived to perform a close-up study of our Sun and its inner heliosphere to better understand the behaviour of our star. The mission will provide the clues to discover how the Sun creates and controls the solar wind and thereby affects the environments of all the planets. The spacecraft is equipped with...

In space software development there are strong robustness requirements that need advanced simulation techniques and tools to analyze the system behavior in the presence of faults. Even more, those simulation tools should provide the ability to communicate embedded software under development with another real working systems using standardized inter...

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 whe...

In addition to functional simulation for validation of hardware/software designs, there are additional robustness requirements that need advanced simulation techniques and tools to analyze the system behavior in the presence of faults. In this paper, we present the design of a fault injection framework for LEON3, a 32bit SPARC CPU based system used...

Software implemented fault injection tools (SWIFI) use fault injectors to carry out the fault injection campaign defined in a GUI-based application. However, the communication between the fault injector and the application is defined in an ad-hoc manner. This paper describes an XML schema formalisation approach for the definition of fault sets whic...

Several traditional VHDL fault injection mechanisms like mutants or saboteurs have been adapted to SystemC model descriptions. The main drawback of these approaches is the necessity of source code modification to carry out the fault injection campaigns. In this paper, we propose the use of Dynamic Binary Instrumentation (DBI) to insert binary trans...

Transaction Level Modelling (TLM) has been widely accepted as systems modelling framework focused in system components communication. This approach allows efficient accurate estimation and rapid design space exploration. Besides of the functional simulation for validation of a hardware/software designs, there are additional reliability requirements...

Java is a successful programming environment and its use has grown from little embedded applications until enterprise network servers based on J2EE. This intensive use of Java demands the validation of their fault tolerance mechanisms to avoid unexpected behavior of the applications at runtime. This paper describes the design and implementation of...

The DPWS (Devices Profile for Web Services) specification enables devices, including small-scale ones, to be integrated seamlessly in service oriented architecture (SOA). Complex enterprise applications are able to access devices functionalities in a Web Service fashion. In some cases, specific applications might require secure transactions that ev...

We have recently been witness to a great evolution in the area of Wireless Sensor Networks (WSN) mainly down to an improvement in the hardware of the sensor nodes (miniaturization of the pieces, increase in ROM and RAM memory, greater energy resources, etc). This, together with the application possibilities that this type of network offers us, has...

This paper describes an XML schema formalization approach for the definition of basic fault sets which specify memory and/or register value corruption in microprocessor-based systems. SWIFI (software implemented fault injection) tools use fault injectors to carry out the fault injection campaign defined in a GUI-based application. However, the comm...

Este artículo describe la experiencia y el entorno desarrollado para la enseñanza de aplicaciones multihilo y controladores de dispositivo en entornos Windows. La docencia de estos temas suele quedar fuera de los programas académicos de las titulaciones de electrónica por los conocimientos previos de sistemas operativos necesarios para abordar su e...