Performance-Reliability Trade-Off in Graphics Processing Units

International audienceWe show that most performance improvements in GPUs increase the number of executions correctly completed before experiencing a failure.We consider four different performance improvements: architectural solutions, software implementations, compiler optimizations, and degree of parallelism

A ação monitória em face da fazenda pública

Orientador: Prof. Joaquim Munhoz de MelloMonografia (graduação) - Universidade Federal do Paraná,Setor de Ciências Jurídicas, Curso de Graduação em DireitoA ação monitória foi instituída no ordenamento jurídico brasileiro através da lei n.° 9.079, de 14 de julho de 1995, que inseriu os artigos 1.102a, 1.102b e 1.102c no livro dos procedimentos especiais do código de processo civil. esta ação tem por finalidade propiciar aos credores que possuem documentos escritos, sem eficácia de títulos executivos, a soma em dinheiro, entrega de coisa fungível ou determinado bem móvel, de forma antecipada,sem a morosidade natural do processo de conhecimento, que necessita de sentença de mérito transitada em julgado, para que o processo executivo se inicie. estando corretamente instruída a petição inicial, o magistrado ordenará a expedição do mandado pra que o ré pague ou entregue a coisa no prazo de quinze dias. se o demandado satisfizer a obrigação, ficara isento de custas e honorários advocatícios. porém se apresentar defesa, o processo seguirá pelo rito do procedimento ordinário. os embargos serão processados nos próprios autos da ação monitória e sem a prévia garantia de juízo. na hipótese do réu não apresentar embargos ou estes forem rejeitados, o mandado inicial constituir se á em titulo executivo e o efeito prosseguirá na forma prevista no livro II, capitulo II e IV do código de processo civil. a fazenda publica possui prerrogativas especiais quando figura no pólo passivo de execução. a propositura de ação monitoria perante a fazenda pública depende da observância de tais prerrogativas. o procedimento monitório é uma das manifestações mais importantes de procedimento diferenciado visando à efetividade do processo

Changes in seed quality during fruit maturation of sweet pepper

Studies regarding seed maturation are important to determine the ideal fruit development stage for harvesting in order to obtain high-quality seeds. Changes in sweet pepper (Capsicum annuum L.) seed quality were monitored during seed development in order to identify the stage of maximum quality of the seeds and the optimum harvest date. Fruits harvested from 20 to 75 days after anthesis (DAA) with step of five days were grouped according to maturity stage (green, yellow, red and intense red color outside). Before seed extraction, the fruit weigh, diameter and length were determined. Seed water content, seed dry weight, 1.000-seed weight, germination, first count, speed emergence index, seedling length, accelerated aging and electrical conductivity tests were performed. Mass maturity of the seeds was attained at 75 DAA, when seed water content was 47.3 % and the fruits were red. Sweet pepper seeds with high germination and vigour should be harvested when fruits are completely red outside, at 75 DAA

Experimental evaluation of neutron-induced errors on a multicore RISC-V platform

Paper accepted on 28th IEEE IOLTS 2022International audienceRISC-V architectures have gained importance in the last years due to their flexibility and open-source Instruction Set Architecture (ISA), allowing developers to efficiently adopt RISC-V processors in several domains with a reduced cost. For application domains, such as safety-critical and mission-critical, the execution must be reliable as a fault can compromise the system's ability to operate correctly. However, the application's error rate on RISC-V processors is not significantly evaluated, as it has been done for standard x86 processors. In this work, we investigate the error rate of a commercial RISC-V ASIC platform, the GAP8, exposed to a neutron beam. We show that for computing-intensive applications, such as classification Convolutional Neural Networks (CNN), the error rate can be 3.2× higher than the average error rate. Additionally, we find that the majority (96.12%) of the errors on the CNN do not generate misclassifications. Finally, we also evaluate the events that cause application interruption on GAP8 and show that the major source of incorrect interruptions is application hangs (i.g., due to an infinite loop or a racing condition)

Estudo multicêntrico comparativo do tratamento de fraturas diafisárias multifragmentárias de tíbia com hastes bloqueadas não-fresadas e placas em ponte

OBJECTIVE: A prospective, randomized study to compare patients with closed, multi-fragmented tibial diaphyseal fractures treated using one of two fixation methods undertaken during minimally invasive surgery: nonreamed interlocking intramedullary nails or bridging plates. MATERIALS AND METHODS: Forty-five patients were studied; 22 patients were treated with bridging plates, 23 with interlocking nails without reaming. All fractures were Type B and C (according to the AO classification). RESULTS: Clinical and radiographic healing occurred in all cases. No cases of infection occurred. The healing time for patients who received nails was longer (4.32 weeks on average) than the healing time for those who received plates (P = 0.026). No significant differences were observed between the two methods regarding ankle mobility for patients in the two groups. CONCLUSIONS: The healing time was shorter with the bridging plate technique, although no significant functional differences were found.OBJETIVOS: Estudo prospectivo e randomizado comparou pacientes com fraturas diafisárias multifragmentárias fechadas de tíbia, tratados com dois métodos de fixação: hastes intramedulares bloqueadas não-fresadas e placas em ponte. MATERIAL E MÉTODOS: Foram estudados 45 pacientes sendo utilizadas 22 placas em ponte e 23 hastes bloqueadas. Todas as fraturas foram tipos B e C (Classificação AO). RESULTADOS: A consolidação clínica e radiográfica ocorreu em todos os casos. Não houve caso de infecção. Verificou-se que o tempo de consolidação dos pacientes que receberam haste foi maior (em média 4,32 semanas) do que o tempo de consolidação daqueles que receberam placa (p = 0,026). Não foram observadas diferenças estatisticamente significantes entre os dois métodos no tocante à mobilidade do tornozelo nos pacientes dos dois grupos. CONCLUSÕES: O tempo de consolidação foi menor com uso de placas em ponte, porém sem diferenças funcionais significantes

Protecting GPU's Microarchitectural Vulnerabilities via Effective Selective Hardening

Graphics Processing Units (GPUs) are today adopted in several domains for which reliability is fundamental, such as self-driving cars and autonomous machines. Unfortunately, on one side GPUs have been shown to have a high error rate and, on the other side, the constraints imposed by real-time safety-critical applications make traditional, costly, replication-based hardening solutions inadequate. This paper proposes an effective microarchitectural selective hardening of GPU modules to mitigate those faults that affect instructions correct execution. We first characterize, through Register-Transfer Level (RTL) fault injections, the architectural vulnerabilities of a GPU model (FlexGripPlus). We specifically target transient faults in the functional units and pipeline registers of a GPU core. Then, we apply selective hardening by triplicating the locations in each module that we found to be more critical. The results show that selective hardening using Triple Modular Redundancy (TMR) can correct 85% to 99% of faults in the pipeline registers and from 50% to 100% of faults in the functional units. The proposed selective TMR strategy reduces the hardware overhead by up to 65% when compared with traditional TMR

Revealing GPUs Vulnerabilities by Combining Register-Transfer and Software-Level Fault Injection

The complexity of both hardware and software makes GPUs reliability evaluation extremely challenging. A low level fault injection on a GPU model, despite being accurate, would take a prohibitively long time (months to years), while software fault injection, despite being quick, cannot access critical resources for GPUs and typically uses synthetic fault models (e.g., single bit-flips) that could result in unrealistic evaluations. This paper proposes to combine the accuracy of Register-Transfer Level (RTL) fault injection with the efficiency of software fault injection. First, on an RTL GPU model (FlexGripPlus), we inject over 1.5 million faults in low-level resources that are unprotected and hidden to the programmer, and characterize their effects on the output of common instructions. We create a pool of possible fault effects on the operation output based on the instruction opcode and input characteristics. We then inject these fault effects, at the application level, using an updated version of a software framework (NVBitFI). Our strategy reduces the fault injection time from the tens of years an RTL evaluation would need to tens of hours, thus allowing, for the first time on GPUs, to track the fault propagation from the hardware to the output of complex applications. Additionally, we provide a more realistic fault model and show that single bit-flip injection would underestimate the error rate of six HPC applications and two convolutional neural networks by up to 48parcent (18parcent on average). The RTL fault models and the injection framework we developed are made available in a public repository to enable third-party evaluations and ease results reproducibility

Characterizing Deep Neural Networks Neutrons-Induced Error Model

International audienceWe characterize the fault models for Deep Neural Networks (DNNs) in GPUs exposed to neutron. We observe tolerable and critical errors, and show that ECC is not effective in reducing critical errors