271 research outputs found

    Middleware Fault Tolerance Support for the BOSS Embedded Operating System

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    Critical embedded systems need a dependable operating system and application. Despite all efforts to prevent and remove faults in system development, residual software faults usually persist. Therefore, critical systems need some sort of fault tolerance to deal with these faults and also with hardware faults at operation time. This work proposes fault-tolerant support mechanisms for the BOSS embedded operating system, based on the application of proven fault tolerance strategies by middleware control software which transparently delivers the added functionality to the application software. Special attention is taken to complexity control and resource constraints, targeting the needs of the embedded market.Fundação para a Ciência e a Tecnologia (FCT

    Application-level fault tolerance in real-time embedded systems

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    Critical real-time embedded systems need to make use of fault tolerance techniques to cope with operation time errors, either in hardware or software. Fault tolerance is usually applied by means of redundancy and diversity. Redundant hardware implies the establishment of a distributed system executing a set of fault tolerance strategies by software, and may also employ some form of diversity, by using different variants or versions for the same processing. This work proposes and evaluates a fault tolerance framework for supporting the development of dependable applications. This framework is build upon basic operating system services and middleware communications and brings flexible and transparent support for application threads. A case study involving radar filtering is described and the framework advantages and drawbacks are discussed.Fundação para a Ciência e a Tecnologia (FCT

    Implementation of middleware fault tolerance support for real-time embedded applications

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    Critical real-time embedded systems need to apply fault tolerance strategies to deal with operation time errors, either in hardware or software. In this paper we present the ongoing work to provide application fault tolerance by means of implementing middleware transparent support over the BOSS embedded operating system. The middleware uses a publishersubscriber protocol and enables the execution of several fault tolerance strategies with minimum burden to the application level softwareFundação para a Ciência e a Tecnologia (FCT

    Applying aspects to a real-time embedded operating system

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    The application of aspect-oriented programming (AOP) to the embedded operating system domain is still a very controversial topic, as this area demands high performance and small memory footprint. However, recent studies quantifying aspects overheads in AspectC++ show that the resource cost is very low. Therefore, operating system development may benefit with the modularization of crosscutting concerns and system specialization offered by AOP. This paper addresses our experience in applying aspects to synchronization (mutual exclusion) and logging in a real-time embedded operating system (BOSS). Furthermore, we present our ideas for future investigation in aspect-oriented implementations for fault tolerance, middleware customization and platform variability.(undefined

    Sharp affine Sobolev type inequalities via the Lp Busemann–Petty centroid inequality

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    We show that the Lp Busemann-Petty centroid inequality provides an elementary and powerful tool to the study of some sharp affine functional inequalities with a geometric content, like log-Sobolev, Sobolev and Gagliardo-Nirenberg inequalities. Our approach allows also to characterize directly the corresponding equality cases.Coordenação de aperfeiçoamento de pessoal de nivel superiorInstituto Nacional de Matemática Pura e AplicadaConselho Nacional de Desenvolvimento Científico e TecnológicoFundação de Amparo a Pesquisa do Estado de Minas Gerai

    Aspect-oriented fault tolerance for real-time embedded systems

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    Real-time embedded systems for safety-critical applications have to introduce fault tolerance mechanisms in order to cope with hardware and software errors. Fault tolerance is usually applied by means of redundancy and diversity. Redundant hardware implies the establishment of a distributed system executing a set of fault tolerance strategies by software, and may also employ some form of diversity, by using different variants or versions for the same processing. This paper describes our approach to introduce fault tolerance in distributed embedded systems applications, using aspect-oriented programming (AOP). A real-time operating system sup-porting middleware thread communication was integrated to a fault tolerant framework. The introduction of fault tolerance in the system is performed by AOP at the application thread level. The advantages of this approach include higher modularization, less efforts for legacy systems evolution and better configurability for testing and product line development. This work has been tested and evaluated successfully in several fault tolerant configurations and presented no significant performance or memory footprint costs.Fundação para a Ciência e a Tecnologia (FCT

    On the energy performance of iridium satellite IoT technology

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    Most Internet of Things (IoT) communication technologies rely on terrestrial network infrastructure. When such infrastructure is not available or does not provide sufficient coverage, satellite communication offers an alternative IoT connectivity solution. Satellite-enabled IoT devices are typically powered by a limited energy source. However, as of this writing, and to our best knowledge, the energy performance of satellite IoT technology has not been investigated. In this paper, we model and evaluate the energy performance of Iridium satellite technology for IoT devices. Our work is based on real hardware measurements. We provide average current consumption, device lifetime, and energy cost of data delivery results as a function of different parameters. Results show, among others, that an Iridium-enabled IoT device, running on a 2400 mAh battery and sending a 100-byte message every 100 min, may achieve a lifetime of 0.95 years. However, Iridium device energy performance decreases significantly with message rate.This work was supported in part by the Spanish Government through project PID2019- 106808RA-I00, AEI/FEDER, EU, and by Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya through project 2017 SGR 376.Postprint (published version

    Genetic Risk Factors and Lysosomal Function in Parkinson Disease

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    Parkinson disease is a complex disease that has multiple genetic and environmental factors. To achieve the early diagnosis and to be able to modify the disease progression, efforts are being made to identify individuals at risk. About 20 year ago, an evidence of major prevalence of Parkinsonism in patients with Gaucher Disease reported by studies worldwide led to the putative involvement of the GBA gene. Nowadays, the link from a rare disease with a common disease is well known and it is confirmed that mutations in the GBA gene are the most important genetic risk factor. Apart from rare mutations, genetic association studied appointed common variants in genes well associated with familial cases as LRRK2 and SNCA may also contribute to the increased risk for sporadic cases. Other common variants in the MAPT gene were also reported. At least, genetic studies have been observed an excessive burden of relevant variants in genes with lysosomal function. Thus, a synergistic action of variants in genes that codifies proteins involved with the lysosome may be a mean of modulating the risk. In this chapter, we review the most robust genetic risk factor and the relevance of lysosomal function for Parkinson disease

    A non-destructive X-ray fluorescence method of analysis of formalin fixed-paraffin embedded biopsied samples for biomarkers for breast and colon cancer

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    Authors acknowledge Centro Hospitalar Barreiro-Montijo for allowing the current investigation and providing the samples. Publisher Copyright: © 2023 The AuthorsIn this work we present a methodology for the non-destructive elemental determination of formalin-fixed paraffin-embedded (FFPE) human tissue samples based on the Fundamental Parameters method for the quantification of micro Energy Dispersive X Ray Fluorescence (micro-EDXRF) area scans. This methodology intended to overcome two major constraints in the analysis of paraffin embedded tissue samples – retrieval of optimal region of analysis of the tissue within the paraffin block and the determination of the dark matrix composition of the biopsied sample. This way, an image treatment algorithm, based on R® tool to select the regions of the micro-EDXRF area scans was developed. Also, different dark matrix compositions were evaluated using varying combinations of H, C, N and O until the most accurate matrix was found: 8% H, 15% C, 1% N and 60% O for breast FFPE samples and 8% H, 23% C, 2% N and 55% O for colon. The developed methodology was applied to paired normal-tumour samples of breast and colon biopsied tissues in order to gauge potential elemental biomarkers for carcinogenesis in these tissues. The obtained results showed distinctive biomarkers for breast and for colon: there was a significant increase of P, S, K and Fe in both tissues, while a significant increase of Ca an Zn concentrations was also determined for breast tumour samples.publishersversionpublishe

    Comparison of denture microwave disinfection and conventional antifungal therapy in the treatment of denture stomatitis: a randomized clinical study

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    Objective. the aim of this study was to compare the effectiveness of denture microwave disinfection and antifungal therapy on treatment of denture stomatitis.Study Design. Sixty denture wearers with denture stomatitis (3 groups; n = 20 each), were treated with nystatin or denture microwave disinfection (1 or 3 times/wk) for 14 days. Mycologic samples from palates and dentures were quantified and identified with the use of Chromagar, and clinical photographs of palates were taken. Microbiologic and clinical data were analyzed with the use of a series of statistical tests (alpha = .05).Results. Both treatments similarly reduced clinical signs of denture stomatitis and growth on palates and dentures at days 14 and 30 (P > .05). At sequential appointments, the predominant species (P < .01) isolated was C. albicans (range 98%-53%), followed by C. glabrata (range 22%-12%) and C. tropicalis (range 25%-7%).Conclusions. Microwave disinfection, at once per week for 2 treatments, was as effective as topical antifungal therapy for treating denture stomatitis. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:469-479)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CESMAC Univ Ctr, Sch Dent, Maceio, BrazilUniv Estadual Ponta Grossa, Dept Dent, Ponta Grossa, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilUNESP Univ Estadual Paulista, Araraquara Dent Sch, Araraquara, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilFAPESP: 2005/03211-6FAPESP: 2005/04695-7Web of Scienc
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