2015
Autores
Pinho, LM; Moore, B; Michell, S; Taft, ST;
Publicação
Ada-Europe
Abstract
This paper extends the authors earlier proposal for providing Ada with support for fine-grained parallelism with an execution model based on the concept of abstract executors, detailing the progress guarantees that these executors must provide and how these can be assured even in the presence of potentially blocking operations. The paper also describes how this execution model can be applied to real-time systems. © Springer International Publishing Switzerland 2015.
2015
Autores
Nelissen, G; Pereira, D; Pinho, LM;
Publicação
Ada-Europe
Abstract
Verification and testing are two of the most costly and time consuming steps during the development of safety critical systems. The advent of complex and sometimes partially unpredictable computing architectures such as multicore commercial-of-the-shelf platforms, together with the composable development approach adopted in multiple industrial domains such as avionics and automotive, rendered the exhaustive testing of all situations that could potentially be encountered by the system once deployed on the field nearly impossible. Run-time verification (RV) is a promising solution to help accelerate the development of safety critical applications whilst maintaining the high degree of reliability required by such systems. RV adds monitors in the application, which check at run-time if the system is behaving according to predefined specifications. In case of deviations from the specifications during the runtime, safeguarding measures can be triggered in order to keep the system and its environment in a safe state, as well as potentially attempting to recover from the fault that caused the misbehaviour. Most of the state-of-the-art on RV essentially focused on the monitor generation, concentrating on the expressiveness of the specification language and its translation in correct-by-construction monitors. Few of them addressed the problem of designing an efficient and safe run-time monitoring (RM) architecture. Yet, RM is a key component for RV. The RM layer gathers information from the monitored application and transmits it to the monitors. Therefore, without an efficient and safe RM architecture, the whole RV system becomes useless, as its inputs and hence by extension its outputs cannot be trusted. In this paper, we discuss the design of a novel RM architecture suited to safety critical applications. © Springer International Publishing Switzerland 2015.
2015
Autores
Souto, P; Sousa, PB; Davis, RI; Bletsas, K; Tovar, E;
Publicação
2015 IEEE 21ST INTERNATIONAL CONFERENCE ON EMBEDDED AND REAL-TIME COMPUTING SYSTEMS AND APPLICATIONS
Abstract
Schedulability analyses, while valuable in theoretical research, cannot be used in practice to reason about the timing behaviour of a real-time system without including the overheads induced by the implementation of the scheduling algorithm. In this paper, we provide an overhead-aware schedulability analysis based on demand bound functions for two hard real-time semi-partitioned scheduling algorithms, EDFWM- and C=D. This analysis is based on a novel implementation that uses a global clock to reduce the overheads incurred due to the release jitter of migrating subtasks. The analysis is used to guide the respective off-line task assignment and splitting procedures. Finally, results of an evaluation are provided highlighting how the different algorithms perform with and without a consideration of overheads.
2015
Autores
Pego, Ana; Bernardo, Maria do Rosário Matos;
Publicação
Dos Algarves: a Multidisciplinary e-Journal
Abstract
O presente artigo tem como objeto os resultados dum estudo que teve por objetivo a investigação do uso dos sistemas e tecnologias de informação (STI) no turismo em espaço rural (TER) na região do Algarve. Os resultados foram obtidos através de um questionário eletrónico, direcionado a proprietários e/ou gestores de 51 unidades TER, no qual se procurou identificar o impacto dos STI nas variáveis: tomada de decisão; satisfação dos gestores quanto ao uso dos STI; qualidade do serviço de reservas de quarto; e resultados financeiros. O estudo permitiu concluir que, de uma forma geral, a utilização dos STI são uma componente importante na gestão das unidades TER e têm impactos positivos na identificação de problemas e minimização do seu tempo de resolução; na confiança depositada no sistema e linguagem utilizada no computador; na qualidade das reservas de quartos; e nos resultados financeiros por via da inovação em tecnologia e existência de rede na organização.;This article aims to present the results of a study that investigated the use of information
systems and technologies (IST) in tourism in rural space (TRS) in the Algarve region. The
results were obtained through an electronic questionnaire given to the owners and/or
managers of fifty one units TRS, in which we tried to identify the impact of IST in the
following variables: decision making, satisfaction of managers in the use of IST, quality of
room reservations service, and financial results. The study concluded that, in general, the
use of IST are an important component in the TRS units of management and have positive
impacts in identifying problems and minimizing their time resolution, confidence in the
system and language used in the computer, the quality of rooms reservations, and
financial results through innovation in technology, and network existence in the
organization.
2015
Autores
Schlemmer, E;
Publicação
Revista Diálogo Educacional
Abstract
2015
Autores
Schlemmer, E; Backes, L;
Publicação
Advances in Educational Technologies and Instructional Design
Abstract
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