Lock-V: a heterogeneous fault tolerance architecture based on Arm and RISC-V

This article presents Lock-V, a heterogeneous fault tolerance architecture that explores a dual-core lockstep (DCLS) technique to mitigate single event upset (SEU) and common-mode failure (CMF) problems. The Lock-V was deployed in two versions, Lock-VA and Lock-VM by applying design diversity in two processor architectures at the instruction set architecture (ISA)-level. Lock-VA features an Arm Cortex-A9 with a RISC-V RV64GC, while Lock-VM includes an Arm Cortex-M3 along with a RISC-V RV32IMA processor. The solution explores fieldprogrammable gate array (FPGA) technology to deploy softcore versions of the RISC-V processors, and dedicated accelerators for performing error detection and triggering the software rollback system used for error recovery. To test Lock-V in both versions, a fault-injection mechanism was implemented to cause bit-flips in the processor registers, a common problem usually present in heavy radiation environments.This work has been supported by FCT - Fundação para a Ciência e a Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

Towards a heterogeneous fault-tolerance architecture based on Arm and RISC-V processors

Computer systems are permanently present in our daily basis in a wide range of applications. In systems with mixed-criticality requirements, e.g., autonomous driving or aerospace applications, devices are expected to continue operating properly even in the event of a failure. An approach to improve the robustness of the device's operation lies in enabling faulttolerant mechanisms during the system's design. This article proposes Lock-V, a heterogeneous architecture that explores a Dual-Core Lockstep (DCLS) fault-tolerance technique in two different processing units: a hard-core Arm Cortex-A9 and a softcore RISC-V-based processor. It resorts a System-on-Chip (SoC) solution with software programmability (available trough the hard-core Arm Cortex-A9) and field-programmable gate array (FPGA) technology, taking advantages from the latter to support the deployment of the RISC-V soft-core along with dedicated hardware accelerators towards the realization of the DCLS.This work has been supported by national funds through FCT -Fundação para a Ciência e a Tecnologia within the Project Scope: UID/CEC/00319/2019

Microphone array for speaker localization and identification in shared autonomous vehicles

With the current technological transformation in the automotive industry, autonomous vehicles are getting closer to the Society of Automative Engineers (SAE) automation level 5. This level corresponds to the full vehicle automation, where the driving system autonomously monitors and navigates the environment. With SAE-level 5, the concept of a Shared Autonomous Vehicle (SAV) will soon become a reality and mainstream. The main purpose of an SAV is to allow unrelated passengers to share an autonomous vehicle without a driver/moderator inside the shared space. However, to ensure their safety and well-being until they reach their final destination, active monitoring of all passengers is required. In this context, this article presents a microphone-based sensor system that is able to localize sound events inside an SAV. The solution is composed of a Micro-Electro-Mechanical System (MEMS) microphone array with a circular geometry connected to an embedded processing platform that resorts to Field-Programmable Gate Array (FPGA) technology to successfully process in the hardware the sound localization algorithms.This work is supported by: European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 039334; Funding Reference: POCI-01-0247-FEDER-039334]

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Tecnologia Lockstep em processadores Arm e RISC-V recorrendo a uma abordagem loosely- coupled

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e Computadores (área de especialização em Sistemas Embebidos e Computadores)Due to the technological growth during the last few years, a new market is rising, bringing a huge number of devices that interact with the human being and the environment. However, the dependability of those devices becomes more and more a concern. Furthermore, from what has been seen, in terms of performance and power consumption, these computational systems are constantly being improved due to reduced transistor’s size, higher clock frequencies, and lower operating core voltages. However, this leads to a lack in the systems reliability, which turns them more susceptive to faults. For example, systems are becoming more sensitives to radiations that can trigger Single Event Upsets (SEUs) in this new technological generation. This dissertation aims to provide a new solution for fault tolerance systems, named Lock-V, that combines two fault tolerance techniques, in order to answer the current gap. The solution is deployed under the Microsemi SmartFusion2 that includes a Microcontroller Unit (MCU) and an Field-Programmable Gate Array (FPGA) in the same platform, and the solution consists in a Dual-Core Lockstep (DCLS) combined with design diversity at Instruction Set Architecture (ISA) level. The design diversity is achieved by using two different cores, a hard-core Arm Cortex-M3 and a soft-core RISC-V-based processors. The DCLS is supported by an FPGA-based accelerator and it provides error detection capabilities to the system by comparing, in a loosely-coupled fashion, the outputs from the two cores. Moreover, this dissertation provides a friendly framework, that adds to the system recovery capabilities. In order to validate the system, a fault injection mechanism was developed, to test the Lock-V architecture. Since protecting the memory is out of the scope of this dissertation, the fault injections are over the register files, which are usually more vulnerable to faults, excluding the memory. These tests, prove the effectiveness of the Lock-V system as a fault tolerance system. Moreover, Lock-V architecture offers fault tolerance against SEU and protection against Common-Mode Failure (CMF) by applying lockstep technique and design diversity, respectively. Summing up, the Lock-V achieved a high fault coverage taking into account the existing solutions.Nos últimos anos, o grande crescimento tecnológico tem originado o surgimento de novas necessidades, onde dispositivos eletrónicos e seres humanos passam a ter um maior contacto. Este crescimento, contudo, levanta problemas de fiabilidade e segurança. E apesar de na ciência computacional surgirem melhorias de desempenho e de eficiência energética, devido à redução dos transístores, altas frequências de relógio, e baixas tensões de execução do núcleo de processamento, estas trazem consigo lacunas na fiabilidade dos sistemas, tornando-os mas suscetíveis a faltas. Por exemplo, esta nova geração tecnológica é cada vez mais sensível a radiações que podem despoletar Single Event Upset (SEU). Esta dissertação visa fornecer uma nova solução para sistemas tolerantes a falhas, denominada de Lock-V, que combina duas técnicas, de forma a responder à lacuna atual. A solução foi implementada sobre a Microsemi SmartFusion2 que inclui um microcontrolador e um Field-Programmable Gate Array (FPGA) na mesma plataforma, esta solução consiste numa arquitetura Dual-Core Lockstep (DCLS) combinada com diversidade de desenho ao nível do conjunto de instruções que é obtida pelo uso de dois núcleos diferentes, um hard-core Arm Cortex-M3 e um soft-core com base em RICS-V. O DCLS é apoiado por um acelerador desenvolvido na FPGA e proporciona ao sistema a capacidade de deteção de error, através da comparação loosely-coupled das saídas dos núcleos de processamento. Para além disso, esta dissertação fornece uma framework, que adiciona ao sistema a capacidade de auto-recuperação. De forma a validar o sistema, foi desenvolvido um mecanismo de injeção de faltas, que testa a arquitetura Lock-V. Como proteger a memoria está fora do âmbito desta dissertação, e como tal, a injeção de faltas foi aplicada apenas nos registros do processador, que normalmente são os mais vulneráveis a faltas se excluirmos as memórias. Estes testes, provam a eficiência do sistema Lock-V como um sistema tolerante a falhas. Para além disso, esta arquitetura, devido ao seu mecanismo lockstep é um sistema tolerante a falhas contra SEU, e também, devido à diversidade de desenho, apresenta proteção contra falhas de modo comum. Resumidamente, o sistema Lock-V tem grande cobertura de faltas tendo em conta as soluções existentes

Comparative study between biopsy and brushing sampling methods for detection of human papillomavirus in oral and oropharyngeal cavity lesions,

ABSTRACT INTRODUCTION: Many epidemiological studies have suggested that human papillomavirus (HPV), especially type 16, is involved in the genesis of squamous cell carcinoma of the oral cavity and oropharynx, especially in young, non-smoking patients; thus, its detection in lesions in this region is important. OBJECTIVE: To clarify the capacity of the brushing sampling method to detect the presence of HPV in oral or oropharyngeal lesions through polymerase chain reaction (PCR) testing, and to compare the results with those obtained by biopsy. METHODS: Prospective study of adult patients with oral or oropharyngeal lesions assessed by PCR, comparing biopsy specimens with samples obtained by the brushing method. The study was approved by the Research Ethics Committee of the institution. RESULTS: A total of 35 sample pairs were analyzed, but 45.7% of the brushing samples were inadequate (16/35) and, thus, only 19 pairs could be compared. There was agreement of results in 94.7% (18/19) of the pairs, with HPV identified in 16 of them. HPV DNA was detected in 8.6% (3/35) of biopsy and 5.7% (2/35) of brushing samples. CONCLUSION: There was no statistically significant difference between the two methods, but the brushing sampling method showed a higher number of inadequate samples, suggesting that it is an unreliable method for surveillance

Brazilian Journal of Otorhinolaryngology Brazilian Journal of OTORHINOLARYNGOLOGY Comparative study between biopsy and brushing sampling methods for detection of human papillomavirus in oral and oropharyngeal cavity lesions PALAVRAS-CHAVE

Comparative study between biopsy and brushing sampling methods for detection of human papillomavirus in oral and oropharyngeal cavity lesions Brazilian Journal of Otorhinolaryngology, vol. 81, núm. 6, 2015, pp. 598-603 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial São Paulo, Brasil PALAVRAS-CHAV

Equilíbrio dinâmico, estilo de vida e estados emocionais em adultos jovens Dinamic balance, lifestyle and emotional states in young adults

Uma hipótese para explicar algumas desordens periféricas vestibulares seria sua correlação com variáveis do estilo de vida. Assim, a realização de estudos populacionais sobre o tema em adultos jovens é relevante. OBJETIVOS: Analisar a prevalência de indicação de alterações no equilíbrio dinâmico em adultos jovens e sua possível associação com variáveis do estilo de vida, saúde e estados emocionais negativos (pois podem intervir nos resultados). MATERIAL E MÉTODO: Foi realizado um estudo epidemiológico transversal, não-probabilístico, retrospectivo-clínico, em adultos jovens (18-32 anos) de uma comunidade universitária com 751 indivíduos, com média de 22.45± 3.32 anos. Variáveis do estilo de vida, saúde e estados emocionais negativos (EEN), que são depressão, ansiedade e estresse, foram coletadas via entrevista. Teste de Unterberger foi aplicado para averiguar indicação de alteração no equilíbrio dinâmico. Indivíduos com equilíbrio dinâmico alterado (EDA) foram então comparados com os sem alteração (controle). RESULTADOS: Da amostra 642 (83.6%) desviaram menos que 45º enquanto que 109 (14.2%) apresentaram um desvio maior que 45º sendo então considerados o grupo EDA. O grupo EDA apresentou maior prevalência de tabagismo, abuso/dependência de álcool, hipertensão arterial sistêmica e de EEN. CONCLUSÃO: O estudo destaca a ocorrência de EDA que precisa ser comprovado em estudos futurosA one hypothesis to explain some vestibular peripheral disorders is their association with life style. Thus, studies with young adults are relevant. AIM: to analyze the prevalence of dynamic balance alterations in young adults and their possible association with life style variables, health and negative emotional states (since they can impact the outcome). MATERIALS AND METHODS: we carried out a non-probabilistic cross-sectional, clinical-retrospective study with young adults (18-32 years of age) from a university with 751 individuals, with a mean age of 22.45± 3.32 years. Life style, health and negative emotional states (NES) variables - depression, stress and anxiety, were collected by means of an interview. The Unterberger test was used in order to check for indications of dynamic balance alterations. Individuals with altered dynamic balance (ADB) were compared to those without these alterations (controls). RESULTS: From our sample, 642 (83.6%) had less than 45º of deviation, while 109 (14.2%) had greater than 45º deviation and were the considered with ADB. The ADB group had a greater prevalence of smoking, alcohol abuse/dependence, high blood pressure and NES. CONCLUSION: the study highlights the occurrence of ADB which needs to be corroborated in future studie

Seroepidemiological aspects of human infection by Strongyloides stercoralis in Alfenas, southern Minas Gerais, Brazil

Abstract INTRODUCTION: In most Strongyloides stercoralis infected individuals, nematoidosis occurs asymptomatically, but in immunocompromised patients, it can cause hyperinfection. Serological techniques seem to be a good alternative for detecting this parasite. METHODS The frequency of seropositivity for strongyloidiasis in Alfenas, MG, was estimated using the enzyme linked immunosorbent assay on blood samples, between May and August of 2015. RESULTS: Out of 258 samples tested, 53.9% were positive, and the frequency of seropositive individuals was higher in the peripheral districts of the municipality. CONCLUSIONS: The results indicate high seropositivity rates for strongyloidiasis among the residents of Alfenas city