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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Cost-effective dynamic repair for FPGAs in real-time systems / Reparo dinâmico de baixo custo para FPGAs em sistemas tempo-real

Santos, Leonardo Pereira January 2016 (has links)
Field-Programmable Gate Arrays (FPGAs) são largamente utilizadas em sistemas digitais por características como flexibilidade, baixo custo e alta densidade. Estas características advém do uso de células de SRAM na memória de configuração, o que torna estes dispositivos suscetíveis a erros induzidos por radiação, tais como SEUs. TMR é o método de mitigação mais utilizado, no entanto, possui um elevado custo tanto em área como em energia, restringindo seu uso em aplicações de baixo custo e/ou baixo consumo. Como alternativa a TMR, propõe-se utilizar DMR associado a um mecanismo de reparo da memória de configuração da FPGA chamado scrubbing. O reparo de FPGAs em sistemas em tempo real apresenta desafios específicos. Além da garantia da computação correta dos dados, esta computação deve se dar completamente dentro do tempo disponível (time-slot), devendo ser finalizada antes do tempo limite (deadline). A diferença entre o tempo de computação dos dados e a deadline é chamado de slack e é o tempo disponível para reparo do sistema. Este trabalho faz uso de scrubbing deslocado dinâmico, que busca maximizar a probabilidade de reparo da memória de configuração de FPGAs dentro do slack disponível, baseado em um diagnóstico do erro. O scrubbing deslocado já foi utilizado com técnicas de diagnóstico de grão fino (NAZAR, 2015). Este trabalho propõe o uso de técnicas de diagnóstico de grão grosso para o scrubbing deslocado, evitando as penalidades de desempenho e custos em área associados a técnicas de grão fino. Circuitos do conjunto MCNC foram protegidos com as técnicas propostas e submetidos a seções de injeção de erros (NAZAR; CARRO, 2012a). Os dados obtidos foram analisados e foram calculadas as melhores posição iniciais do scrubbing para cada um dos circuitos. Calculou-se a taxa de Failure-in-Time (FIT) para comparação entre as diferentes técnicas de diagnóstico propostas. Os resultados obtidos confirmaram a hipótese inicial deste trabalho que a redução do número de bits sensíveis e uma baixa degradação do período do ciclo de relógio permitiram reduzir a taxa de FIT quando comparadas com técnicas de grão fino. Por fim, uma comparação entre as três técnicas propostas é feita, analisando o desempenho e custos em área associados a cada uma. / Field-Programmable Gate Arrays (FPGAs) are widely used in digital systems due to characteristics such as flexibility, low cost and high density. These characteristics are due to the use of SRAM memory cells in the configuration memory, which make these devices susceptible to radiation-induced errors, such as SEUs. TMR is the most used mitigation technique, but it has an elevated cost both in area as well as in energy, restricting its use in low cost/low energy applications. As an alternative to TMR, we propose the use of DMR associated with a repair mechanism of the FPGA configuration memory called scrubbing. The repair of FPGA in real-time systems present a specific set of challenges. Besides guaranteeing the correct computation of data, this computation must be completely carried out within the available time (time-slot), being finalized before a time limit (deadline). The difference between the computation time and the deadline is called the slack and is the time available to repair the system. This work uses a dynamic shifted scrubbing that aims to maximize the repair probability of the configuration memory of the FPGA within the available slack based on error diagnostic. The shifted scrubbing was already proposed with fine-grained diagnostic techniques (NAZAR, 2015). This work proposes the use of coarse-grained diagnostic technique as a way to avoid the performance penalties and area costs associated to fine-grained techniques. Circuits of the MCNC suite were protected by the proposed techniques and subject to error-injection campaigns (NAZAR; CARRO, 2012a). The obtained data was analyzed and the best scrubbing starting positions for each circuit were calculated. The Failure-in-Time (FIT) rates were calculated to compare the different proposed diagnostic techniques. The obtained results validated the initial hypothesis of this work that the reduction of the number of sensitive bits and a low degradation of the clock cycle allowed a reduced FIT rate when compared with fine-grained diagnostic techniques. Finally, a comparison is made between the proposed techniques, considering performance and area costs associated to each one.
22

Neutron Beam Testing Methodology and Results for a Complex Programmable Multiprocessor SoC

Anderson, Jordan Daniel 01 March 2019 (has links)
The Xilinx Multiprocessor System-on-Chip (MPSoC) is a complex device that uses 16nm FinFET technology to combine multiple processors, a large amount of FPGA resources, and many I/O interfaces on a single chip die. These features make the MPSoC a high-performance and architecturally flexible device. The potential computing power makes the MPSoC ideal for many embedded applications including terrestrial and space applications. The MPSoC, however, does not have extensive radiation history as many other devices have. The extent of the effect that ionized particles may have on the MPSoC is not well established. To solve this problem, neutron radiation testing can be used to determine the device's susceptibility to single-event upsets (SEUs). Though this thesis is not intended to qualify the MPSoC for space, this work does provide useful neutron radiation test data that helps to characterize the susceptible nature of the device. This thesis summarizes the SEU results obtained from neutron testing on the UltraScale+ MPSoC ZU9EG device. A series of three neutron beam tests were performed on the MPSoC ZU9EG at Los Alamos National Laboratories (LANL). Testing was performed using a novel testing methodology to collect SEU counts on the programmable logic and the processing system simultaneously. These results show a 10.1× improvement of the programmable logic CRAM over the previous Xilinx UltraScale device series.
23

Neutron Beam Testing Methodology and Results for a Complex Programmable Multiprocessor SoC

Anderson, Jordan Daniel 01 March 2019 (has links)
The Xilinx Multiprocessor System-on-Chip (MPSoC) is a complex device that uses 16nm FinFET technology to combine multiple processors, a large amount of FPGA resources, and many I/O interfaces on a single chip die. These features make the MPSoC a high-performance and architecturally flexible device. The potential computing power makes the MPSoC ideal for many embedded applications including terrestrial and space applications.The MPSoC, however, does not have extensive radiation history as many other devices have. The extent of the effect that ionized particles may have on the MPSoC is not well established. To solve this problem, neutron radiation testing can be used to determine the device's susceptibility to single-event upsets (SEUs). . Though this thesis is not intended to qualify the MPSoC for space, this work does provide useful neutron radiation test data that helps to characterize the susceptible nature of the device. This thesis summarizes the SEU results obtained from neutron testing on the UltraScale+ MPSoC ZU9EG device. A series of three neutron beam tests were performed on the MPSoC ZU9EG at Los Alamos National Laboratories (LANL). Testing was performed using a novel testing methodology to collect SEU counts on the programmable logic and the processing system simultaneously. These results show a $10.1 timess improvement of the programmable logic CRAM over the previous Xilinx UltraScale device series.
24

Chemical Scrubbing of Odorous Fumes Emitted from Hot-Melted Asphalt Plants

Chen, Po-cheng 11 August 2011 (has links)
Hot-melted asphalt (HMA) plants use sized gravels, asphalt and/or recycled asphalt as raw materials. In the plant, the materials are heated to certain preset temperatures and blended at fixed ratios at around 170oC to prepare the required HMA for road paving. In the asphalt-melting, hot-blending and dumping operations, fumes and particulates emit from the process equipments. The emitted gases contain various volatile organic compounds (VOCs) and poly aromatic hydrocarbons (PAHs) which are harmful to the health of the plant workers and nearby residents. Complaints from the residents also come with the fume and odorous emissions. In this study, an oxidation-reduction-in-series scrubbing process was tested to remove odorous compounds in waste gases emitted from HMA plants. Waste gas samples for test were collected from the vent hole of an oven which contains a heated sample of asphalt or recycled asphalt concrete. Sodium hypochlorite solution was used to scrub and oxidize the compounds and hydrogen peroxide to reduce the chlorine emitted from the oxidative scrubber. A gas chromatography with a mass spectrophotometric detector (GC-MSD) was used for the identification of the odorous species and their concentrations in the waste gases. Sensory tests were also used to determine the odor removal efficiency. GC-MSD examination results indicates that alkanes, arenes, alkenes, halides, esters, and carbonyl compounds were detected in the test gas. Scrubbing test results indicate that with oxidative solution of 50-60 mg/L residual chlorine at pH 7.0-7.5 and reductive solution of 35 mg/L hydrogen peroxide at pH >12, over 90% of the VOCs in the tested gas could be removed. Odor intensities could be reduced from 3,090 (expressed as dilutions to threshold) to 73. Pungent asphalt odor in the test gas was turned into slight sulfur smell after the scrubbing. For removing the odors from 500 Nm3/min of the flue gas vented from a HMA plant, an analysis indicates the required total cost for chemicals (sodium hypochlorite solution, hydrogen peroxide and sodium hydroxide) added to the scrubbers was around 2,800 NT$/day (US$ 95/day) for a daily operation time of 10 hours. The cost is far lower than that by the traditional thermal incineration one (25,000 NT$/day or US$ 850/day) or by the regenerative thermal oxidation (RTO) one (14,300 NT$/day or US$ 485/day). This study has successfully developed an economical and effective chemical scrubbing technology for the removal of odorous compounds in gases emitted from HMA plants.
25

Wet Scrubbing and Activated-carbon Adsorption of Odorous Compounds in Vented Gases from Food-cooking Operations

Chen, Cheng-wei 26 June 2006 (has links)
In this study, wet scrubbing and activated-carbon adsorption technologies were tested to investigate their abilities to remove total hydrocarbons (THCs) and other odorous compounds in the effluent gas from food-cooking operations such as frying, toasting, grilling, and steaming. A full-scale scrubber (gas-liquid contacting cross section 0.58 m¡Ñ0.50 m, height 0.80 m) was used in the present study for testing its performance on removing odorous compounds from a gas stream of 102 m3/min drawn from a Japanese-type grilling restaurant located in the Kaohsiung city. The scrubbing liquid had a flow rate of 67.2 L/min which is equivalent to a liquid/gas ratio of (L/G) 0.0065 m3 liquid/(m3 gas). Tap water, aqueous sodium hypochlorite solution, and aqueous hydrogen peroxide solution were used as scrubbing liquids. For the activated carbon tests, a 2-cm i.d. glass column packed with 20 g activated carbon which gives a packing height of 10.5 cm was used to obtain the adsorption isotherms by introducing a 15 L/min gas stream drawn from an oven toasting sausage. The gas flow resulted in a superficial gas velocity of 1.06 m/s over the cross section of the column. In addition, a pilot-scale adsorption unit (cross section 0.50 m sq., packed with 30 kg granular activated carbon) was installed for the adsorption test. A gas flow drawn from a vent of a restaurant kitchen cooking Chinese-type food was introduced into the pilot adsorber. A flow rate of 12.6 m3/min was used and the superficial gas velocity was 0.84 m/s. Results indicate that THC and odor (sensory test) removals of 15-35 and 35-65% were obtained, respectively, form the scrubbing test. There was no significant difference in the performance by using one of water or the two aqueous chemical solutions as the scrubbing liquor. Most of the characteristic food-grilling and flavoring smells were removed by the scrubber and some bitter smells like burnt carbon were found in the scrubbed gas. High moisture contents (around 95% in relative humidity) of the vent gas from the sausage-toasting oven resulted in a significant reduction in the activated carbon adsorption capacity for THCs from the tested gas. From results of the pilot-scale adsorption test, THC removals of 60-80% form the vent gas (around 50-60% in relative humidity) of the Chinese-type kitchen were found during the initial adsorption time of 0-50 hr. A long time (200 hr) operation resulted in a decrease in the THC removal efficiency. However, the adsorber exhibited as an odor equalization unit by reducing peaks of the odor emissions from the kitchen. Characteristic odors from various food cooking operations were reduced by the adsorber. It was estimated that a total of around NT$ 57 is required for the full-scale scrubber for treating the gas flow of 102 m3/min for an operation time of 7 hr per day, and the cost is equivalent to NT$ 1.33/(1,000 m3 gas). The cost for the activated carbon adsorption unit of 13 m3/min was estimated to be NT$ 134 for 8 hr per streaming day. The unit cost is NT$ 22.1/(1,000 m3 gas).
26

Ozone deodoration of wasted gases from rubber processing

Cheng, Li-Yi 01 July 2008 (has links)
This study was aimed at the removal of odorous compounds in gases emitted from rubber processing industries. Odorous gas for test was prepared by mixing fresh air and an odorous gas drawn from an oven in which a sample of rubber powder was kept at 160 and 200 oC, respectively. For ozonation tests, the prepared odorous gas was then premixed with a definite amount of ozone-enriched air before entering into a contact system. The contact system consists of two sieve-plate columns connected in series and each column has four 1-L chambers. Depending on with or without introducing a circulating scrubbing water into the columns, the oxidation reaction could be either wet or dry one. For UV/ozonation (UV/O3) tests, batch reactions were performed in a 3.63-L chamber fitted with an UV lamp inserted in a quartz column. A definite volume of the odorous gas generated from the oven was injected into the chamber containing a definite concentration of ozone. Results from the dry-ozonation tests indicate that that 82 and 70% of VOCs and odorous intensity in the influent gas could be removed, respectively, with the operation conditions of an initial ozone concentration of 4.0 ppm, VOC (methane equivalent) concentrations of 6.5-9.0 ppm, an oxidation temperature of 38.5 oC, and a gas empty-bed-retention time (EBRT) of 8.6 s. Both the VOC and odorous intensity removal efficiencies were roughly proportional to the EBRT in the range of 1.4-11.4 s. Wet-ozonation got 97 and over 90% of VOC and odorous intensity removal, respectively, with the operation conditions of initial ozone concentration 4.0 ppm, VOC (methane equivalent) concentrations 6.5-10.3 ppm, oxidation temperature 37.3 oC, gas EBRT 12 s, and liquid/gas rate ratio 0.01 m3/m3. With conditions similar to those cited above, odor concentration (dilutions to the threshold) in the test gas could be removed from 3,090 to 130 with an EBRT of 14.5 s. Tests also indicate that activated carbon is effective for both physical and chemical removals of the residual VOCs, odorous compounds, and ozone in the effluent gas from the ozonation system. Economical analysis indicates that around NT$ 5.4 is required for treating 1,000 m3 of the tested foul gas by the proposed wet-ozonation and activated carbon adsorption process. Odor concentration (dilutions to the threshold) in a test could be reduced from around 4,000 to 70. Results of UV/O3 tests indicate that the introduction of the 185 nm UV irradiation at the intensity of 5W/3.63L did not help in the additional VOC and odor removals with an initial ozone concentration 4.0 ppm, VOC (methane equivalent) concentrations of 12.2-15.0 ppm, oxidation temperature of 31.5 oC, and reaction time 18.2 s. UV irradiation is not necessary for the ozonation odor removal of the test gas samples.
27

Amine oxidation in carbon dioxide capture by aqueous scrubbing

Voice, Alexander Karl 20 August 2015 (has links)
Amine degradation in aqueous amine scrubbing systems for capturing CO₂ from coal fired power plants is a major problem. Oxygen in the flue gas is the major cause of solvent deterioration, which increases the cost of CO₂ capture due to reduced capacity, reduced rates, increased corrosion, solvent makeup, foaming, and reclaiming. Degradation also produces environmentally hazardous materials: ammonia, amides, aldehydes, nitramines, and nitrosamines. Thus it is important to understand and mitigate amine oxidation in industrial CO₂ capture systems. A series of lab-scale experiments was conducted to better understand the causes of and solutions to amine oxidation. This work included determination of rates, products, catalysts, and inhibitors for various amines at various conditions. Special attention was paid to understanding monoethanolamine (MEA) oxidation, whereas oxidation of piperazine (PZ) and other amines was less thorough. The most important scientific contribution of this work has been to show that amine oxidation in real CO₂ capture systems is much more complex than previously believed, and cannot be explained by mass transfer or reaction kinetics in the absorber by itself, or by dissolved oxygen kinetics in the cross exchanger. An accurate representation of MEA oxidation in real systems must take into account catalysts present (especially Mn and Fe), enhanced oxygen mass transfer in the absorber as a function of various process conditions, and possibly oxygen carriers other than dissolved oxygen in the cross exchanger and stripper. Strategies for mitigating oxidative degradation at low temperature, proposed in this and previous work are less effective or ineffective with high temperature cycling, which is more representative of real systems. In order of effectiveness, these strategies are: selecting an amine resistant to oxidation, reduction of dissolved metals in the system, reduction of the stripper temperature, reduction of the absorber temperature, and addition of a chemical inhibitor to the system. Intercooling in the absorber can reduce amine oxidation and improve energy efficiency, whereas amine oxidation should be considered in choosing the optimal stripper temperature. In real systems, 2-amino-2-methyl-1-propanol (AMP) is expected to be the most resistant to oxidation, followed by PZ and PZ derivatives, then methyldiethanolamine (MDEA), and then MEA. MEA oxidation with high temperature cycling is increased 70% by raising the cycling temperature from 100 to 120 °C, the proposed operational temperature range of the stripper. PZ oxidation is increased 100% by cycling to 150 °C as opposed to 120 °C. Metals are expected to increase oxidation in MEA and PZ with high temperature cycling by 40 - 80%. Inhibitor A is not expected to be effective in real systems with MEA or with PZ. MDEA is also not effective as an inhibitor in MEA, and chelating agents diethylenetriamine penta (acetic acid) (DTPA) and 2,5-dimercapto-1,3,4-thiadiazole (DMcT) are only mildly effective in MEA. Although MEA oxidation in real systems cannot be significantly reduced by any known additives, it can be accurately monitored on a continuous basis by measuring ammonia production from the absorber. Ammonia production was shown to account for two-thirds of nitrogen in degraded MEA at low temperature and with high temperature cycling, suggesting that it is a reliable indicator of MEA oxidation under a variety of process conditions. A proposed system, which minimizes amine oxidation while maintaining excellent rate and thermodynamic properties for CO₂ capture would involve use of 4 m AMP + 2 m PZ as a capture solvent with the stripper at 135 °C, intercooling in the absorber, and use of a corrosion inhibitor or continuous metals removal system. Reducing (anaerobic) conditions should be avoided to prevent excessive corrosion from occurring and minimize the amount of dissolved metals. This system is expected to reduce amine oxidation by 90-95% compared with the base case 7 m MEA with the stripper at 120 °C. / text
28

STUDY OF CHARACTERIZATION OF SUBMICRON COAL PARTICLES DISPERSED IN AIR AND CAPTURE OF COAL PARTICLES BY WATER DROPS IN A SCRUBBING COLUMN

Chakravorty, Utshab 01 January 2012 (has links)
Present day water spray based dust removal technologies do not effectively remove respirable submicron coal and silica dust particles in the underground coal mines causing Coal worker’s pneumoconiosis (CWP). The objective of this research was to study the electrostatic charges present in the airborne coal dust in order to develop efficient water spraying based dust removal technology where water drops charged using ionic compounds and surfactants would be used to capture the oppositely charged coal particles. In an experimental scrubbing column, coal particles dispersed in an air stream by a Fluidized Bed Aerosol Generator were captured by water drops sprayed by an atomizer. Characterization studies performed using an Aerodynamic Particle Sizer and Aerosol Electrometer showed that airborne coal particles have a significant amount of positive charge with an average of 140 elementary units of charge. The capture efficiencies of the water drops evaluated were found to be higher than those predicted by previously determined mathematical models. It was predicted that apart from the effects of Brownian diffusion, interception and impaction, the effect of Coulombic attraction was present and the charge of the water drops was predicted to be between - 2 x 10-6 C and -2 x 10-4 C.
29

Absorption of Nitric Oxide from Flue Gas Using Ammoniacal Cobalt(II) Solutions

Yu, Hesheng January 2012 (has links)
Air emissions from the combustion of fossil fuel, including carbon dioxide, sulfur dioxide, nitrogen dioxide and nitric oxide, have caused severe health and environmental problems. The post-combustion wet scrubbing has been employed for control of carbon dioxide and sulfur dioxide emissions. However, it is restricted by the sparingly water soluble nitric oxide, which accounts for 90-95% of nitrogen oxides. It is desirable and cost-effective to remove nitric oxide from flue gas by existing wet scrubbers for reduced capital costs and foot prints. In this research, absorption of nitric oxide from simulated flue gas using three different absorbents was first conducted in a bubble column system at room temperature and atmospheric pressure. Through performance comparison, ammoniacal cobalt(II) solutions were chosen as the optimum absorbent for nitric oxide absorption. Then the effects of fresh absorbent composition, pH value and temperature on nitric oxide absorption were investigated. Experimental results showed that the best initial NO removal efficiency of 96.45% was measured at the inlet flow rate of 500 mL·min-1; the room temperature of 292.2 K; the pH value of 10.50; and the concentrations of cobalt(II) solution, NO and O2 of 0.06 mol·L-1, 500 ppmv and 5.0%, respectively. For in-depth understanding of NO absorption into ammoniacal cobalt(II) complexes, equilibrium constants of reactions between nitric oxide and penta- and haxa-amminecobalt(II) solutions, respectively were determined using a bubble column reactor, in which the operation was performed continuously with respect to gas phase and batch-wise with respect to liquid phase. The experiments were conducted at temperatures from 298.2 to 310.2 K and pH from 9.06 to 9.37, all under atmospheric pressure. All experimental data fitted well to the following equations: K_NO^5=1.90×10^7 exp(3598.5/T) and K_NO^6=3.56×10^11 exp(1476.4/T), which give the enthalpy of reactions between NO and penta- and hexa-amminecobalt (II) nitrates as ∆H^5=-29.92 kJ·mol^(-1) and ∆H^6=-12.27 kJ·mol^(-1). In kinetic study, a number of experiments were conducted in a home-made double-stirred reactor at temperatures of 298.2 and 303.2 K and pH from 8.50 to 9.87 under atmospheric pressure. The reaction rate constants were calculated with the use of enhancement factor derived for gas absorption accompanied by parallel chemical reactions. The reaction between NO and pentaaminecobalt(II) was first order with respect to NO and pentaamminecobalt(II) ion, respectively. Similarly, the reaction between NO and hexaaminecobalt(II) was also first order with respect to NO and hexaamminecobalt(II) ion, respectively. The forward reaction rate constants of these two reactions were 6.43×10^6 and 1.00×10^7 L·mol-1·s-1, respectively at 298.2 K, and increased to 7.57×106 and 1.12×107 L∙mol-1∙s-1, respectively at 303.2 K. Furthermore, regeneration of used absorbent was attempted but fails. None of the additives tested herein including potassium iodide (KI), sodium persulphate (Na2S5O8) and activated carbon (AC) showed capability of regeneration at room temperature and atmospheric pressure. In addition, the effect of oxygen was investigated. With ammoniacal cobalt(II) compounds a positive effect of oxygen on NO absorption was observed. Calculated NO amount absorbed into the aqueous solution showed that with the oxygen the absorption reaction could be considered as irreversible. This fact was probably the reason for the failure of regeneration of the tested reagents. Last but not least, volumetric liquid-phase mass transfer coefficient, kLa, in some popular industrial absorbers including bubble column (BC), conventional stirred tank reactor (CSTR) and gas-inducing agitated tank (GIAT) were determined by modeling removal of oxygen from water. The experimental results could be well interpreted by mathematical models with 90% of deviations less than ±10 %.
30

Cost-effective dynamic repair for FPGAs in real-time systems / Reparo dinâmico de baixo custo para FPGAs em sistemas tempo-real

Santos, Leonardo Pereira January 2016 (has links)
Field-Programmable Gate Arrays (FPGAs) são largamente utilizadas em sistemas digitais por características como flexibilidade, baixo custo e alta densidade. Estas características advém do uso de células de SRAM na memória de configuração, o que torna estes dispositivos suscetíveis a erros induzidos por radiação, tais como SEUs. TMR é o método de mitigação mais utilizado, no entanto, possui um elevado custo tanto em área como em energia, restringindo seu uso em aplicações de baixo custo e/ou baixo consumo. Como alternativa a TMR, propõe-se utilizar DMR associado a um mecanismo de reparo da memória de configuração da FPGA chamado scrubbing. O reparo de FPGAs em sistemas em tempo real apresenta desafios específicos. Além da garantia da computação correta dos dados, esta computação deve se dar completamente dentro do tempo disponível (time-slot), devendo ser finalizada antes do tempo limite (deadline). A diferença entre o tempo de computação dos dados e a deadline é chamado de slack e é o tempo disponível para reparo do sistema. Este trabalho faz uso de scrubbing deslocado dinâmico, que busca maximizar a probabilidade de reparo da memória de configuração de FPGAs dentro do slack disponível, baseado em um diagnóstico do erro. O scrubbing deslocado já foi utilizado com técnicas de diagnóstico de grão fino (NAZAR, 2015). Este trabalho propõe o uso de técnicas de diagnóstico de grão grosso para o scrubbing deslocado, evitando as penalidades de desempenho e custos em área associados a técnicas de grão fino. Circuitos do conjunto MCNC foram protegidos com as técnicas propostas e submetidos a seções de injeção de erros (NAZAR; CARRO, 2012a). Os dados obtidos foram analisados e foram calculadas as melhores posição iniciais do scrubbing para cada um dos circuitos. Calculou-se a taxa de Failure-in-Time (FIT) para comparação entre as diferentes técnicas de diagnóstico propostas. Os resultados obtidos confirmaram a hipótese inicial deste trabalho que a redução do número de bits sensíveis e uma baixa degradação do período do ciclo de relógio permitiram reduzir a taxa de FIT quando comparadas com técnicas de grão fino. Por fim, uma comparação entre as três técnicas propostas é feita, analisando o desempenho e custos em área associados a cada uma. / Field-Programmable Gate Arrays (FPGAs) are widely used in digital systems due to characteristics such as flexibility, low cost and high density. These characteristics are due to the use of SRAM memory cells in the configuration memory, which make these devices susceptible to radiation-induced errors, such as SEUs. TMR is the most used mitigation technique, but it has an elevated cost both in area as well as in energy, restricting its use in low cost/low energy applications. As an alternative to TMR, we propose the use of DMR associated with a repair mechanism of the FPGA configuration memory called scrubbing. The repair of FPGA in real-time systems present a specific set of challenges. Besides guaranteeing the correct computation of data, this computation must be completely carried out within the available time (time-slot), being finalized before a time limit (deadline). The difference between the computation time and the deadline is called the slack and is the time available to repair the system. This work uses a dynamic shifted scrubbing that aims to maximize the repair probability of the configuration memory of the FPGA within the available slack based on error diagnostic. The shifted scrubbing was already proposed with fine-grained diagnostic techniques (NAZAR, 2015). This work proposes the use of coarse-grained diagnostic technique as a way to avoid the performance penalties and area costs associated to fine-grained techniques. Circuits of the MCNC suite were protected by the proposed techniques and subject to error-injection campaigns (NAZAR; CARRO, 2012a). The obtained data was analyzed and the best scrubbing starting positions for each circuit were calculated. The Failure-in-Time (FIT) rates were calculated to compare the different proposed diagnostic techniques. The obtained results validated the initial hypothesis of this work that the reduction of the number of sensitive bits and a low degradation of the clock cycle allowed a reduced FIT rate when compared with fine-grained diagnostic techniques. Finally, a comparison is made between the proposed techniques, considering performance and area costs associated to each one.

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