Designing single event upset mitigation techniques for large SRAM-Based FPGA components

This thesis presents the study and development of fault-tolerant techniques for programmable architectures, the well-known Field Programmable Gate Arrays (FPGAs), customizable by SRAM. FPGAs are becoming more valuable for space applications because of the high density, high performance, reduced development cost and re-programmability. In particular, SRAM-based FPGAs are very valuable for remote missions because of the possibility of being reprogrammed by the user as many times as necessary in a very short period. SRAM-based FPGA and micro-controllers represent a wide range of components in space applications, and as a result will be the focus of this work, more specifically the Virtex® family from Xilinx and the architecture of the 8051 micro-controller from Intel. The Triple Modular Redundancy (TMR) with voters is a common high-level technique to protect ASICs against single event upset (SEU) and it can also be applied to FPGAs. The TMR technique was first tested in the Virtex® FPGA architecture by using a small design based on counters. Faults were injected in all sensitive parts of the FPGA and a detailed analysis of the effect of a fault in a TMR design synthesized in the Virtex® platform was performed. Results from fault injection and from a radiation ground test facility showed the efficiency of the TMR for the related case study circuit. Although TMR has showed a high reliability, this technique presents some limitations, such as area overhead, three times more input and output pins and, consequently, a significant increase in power dissipation. Aiming to reduce TMR costs and improve reliability, an innovative high-level technique for designing fault-tolerant systems in SRAM-based FPGAs was developed, without modification in the FPGA architecture. This technique combines time and hardware redundancy to reduce overhead and to ensure reliability. It is based on duplication with comparison and concurrent error detection. The new technique proposed in this work was specifically developed for FPGAs to cope with transient faults in the user combinational and sequential logic, while also reducing pin count, area and power dissipation. The methodology was validated by fault injection experiments in an emulation board. The thesis presents comparison results in fault coverage, area and performance between the discussed techniques.

Do police reduce crime? Estimates using the allocation of police forces after a terrorist attack

An important challenge in the crime literature is to isolate causal effects of police on crime. Following a terrorist attack on the main Jewish center in the city of Buenos Aires, Argentina, in July 1994, all Jewish institutions (including schools, synagogues, and clubs) were given 24-hour police protection. Thus, this hideous event induced a geographical allocation of police forces that can be presumed to be exogenous in a crime regression. Using data on the location of car thefts before and after the terrorist attack, we find a large deterrent effect of observable police presence on crime. The effect is local, with little or no appreciable impact outside the narrow area in which the police are deployed.

Stochastic simulation of time-series models combined with geostatistics to predict water-table scenarios in a Guarani Aquifer System outcrop area, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Performance and economic indicators of a large scale fish farming in Mato Grosso, Brazil

Performance and economic indicators of a large scale fish farm that produces round fish, located in Mato Grosso State, Brazil, were evaluated. The 130.8 ha-water surface area was distributed in 30 ponds. Average total production costs and the following economic indicators were calculated: gross income (GI), gross margin (GM), gross margin index (GMI), profitability index (PI) and profit (P) for the farm as a whole and for ten ponds individually. Production performance indicators were also obtained, such as: production cycle (PC), apparent feed conversion (FC), average biomass storage (ABS), survival index (SI) and final average weight (FAW). The average costs to produce an average 2.971 kg.ha-1 per year were: R$ 2.43, R$ 0.72 and R$ 3.15 as average variable, fixed and total costs, respectively. Gross margin and profit per year per hectare of water surface were R$ 2,316.91 and R$ 180.98, respectively. The individual evaluation of the ponds showed that the best pond performance was obtained for PI 38%, FC 1.7, ABS 0.980 kg.m-2, TS 56%, FAW 1.873 kg with PC of 12.3 months. The worst PI was obtained for the pond that displayed losses of 138%, FC 2.6, ABS 0.110 kg.m-2, SI 16% and FAW 1.811 kg. However, large scale production of round-fish in farms is economically feasible. The studied farm displays favorable conditions to improve performance and economic indicators, but it is necessary to reproduce the breeding techniques and performance indicators achieved in few ponds to the entire farm.

Spatial variability of soil CO2 emission in a sugarcane area characterized by secondary information

Soil CO2 emission (FCO2) is governed by the inherent properties of the soil, such as bulk density (BD). Mapping of FCO2 allows the evaluation and identification of areas with different accumulation potential of carbon. However, FCO2 mapping over larger areas is not feasible due to the period required for evaluation. This study aimed to assess the quality of FCO2 spatial estimates using values of BD as secondary information. FCO2 and BD were evaluated on a regular sampling grid of 60 m × 60 m comprising 141 points, which was established on a sugarcane area. Four scenarios were defined according to the proportion of the number of sampling points of FCO2 to those of BD. For these scenarios, 67 (F67), 87 (F87), 107 (F107) and 127 (F127) FCO2 sampling points were used in addition to 127 BD sampling points used as supplementary information. The use of additional information from the BD provided an increase in the accuracy of the estimates only in the F107, F67 and F87 scenarios, respectively. The F87 scenario, with the approximate ratio between the FCO2 and BD of 1.00:1.50, presented the best relative improvement in the quality of estimates, thereby indicating that the BD should be sampled at a density 1.5 time greater than that applied for the FCO2. This procedure avoided problems related to the high temporal variability associated with FCO2, which enabled the mapping of this variable to be elaborated in large areas.

Influência da época de semeadura e do manejo da parte aérea de milheto sobre a soja em sucessão em plantio direto

Uma das grandes limitações do plantio direto é a produção e manutenção da cobertura vegetal. Por esse motivo, o milheto tem-se constituído em boa opção de cultivo no inverno, gerando palhada com decomposição mais lenta viabilizando esse sistema de produção. O objetivo do experimento foi estudar a cultura do milheto em três épocas de semeadura (5/3, 25/3 e 19/4/99), sob condições de sequeiro, e a ceifa da parte aérea (ceifa a cada florescimento e retirada do resíduo vegetal; ceifa a cada florescimento e permanência do resíduo vegetal; ceifa no florescimento e retirada do resíduo vegetal; ceifa no florescimento e permanência do resíduo vegetal e livre crescimento, sem ceifar), bem como seu efeito na produção da soja cultivada na seqüência. Pode-se concluir que o milheto semeado em março e submetido à ceifa na época de cada emissão da panícula proporcionou as maiores produções de matéria seca dessa espécie. Tal cultura demonstrou grande capacidade na produção de matéria seca e, quando semeada em 5 de março e 19 de abril, propiciou as maiores produtividades da soja cultivada em sucessão.

Sandfly fauna in an area endemic for visceral leishmaniasis in Aracaju, State of Sergipe, Northeast Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Motile sperm organelle morphology examination (MSOME): intervariation study of normal sperm and sperm with large nuclear vacuoles

Background: Although the motile sperm organelle morphology examination (MSOME) was developed only as a selection criterion, its application as a method for classifying sperm morphology may represent an improvement in evaluation of semen quality, with potential clinical repercussions. The present study aimed to evaluate individual variations in the motile sperm organelle morphology examination (MSOME) analysis after a time interval.Methods: Two semen samples were obtained from 240 men from an unselected group of couples undergoing infertility investigation and treatment. Mean time interval between the two semen evaluations was 119 +/- 102 days. No clinical or surgical treatment was realized between the two observations. Spermatozoa were analyzed at greater than or equal to 8400 x magnification by inverted microscope equipped with DIC/Nomarski differential interference contrast optics. At least 200 motile spermatozoa per semen sample were evaluated and percentages of normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV/one or more vacuoles occupying >50% of the sperm nuclear area) were determined. A spermatozoon was classified as morphologically normal when it exhibited a normal nucleus (smooth, symmetric and oval nucleus, width 3.28 +/- 0.20 mu m, length 4.75 +/- 0.20 mu m/absence of vacuoles occupying >4% of nuclear area) as well as acrosome, post-acrosomal lamina, neck and tail, besides not presenting cytoplasm around the head. One examiner, blinded to subject identity, performed the entire study.Results: Mean percentages of morphologically normal and LNV spermatozoa were identical in the two MSOME analyses (1.6 +/- 2.2% vs. 1.6 +/- 2.1% P = 0.83 and 25.2 +/- 19.2% vs. 26.1 +/- 19.0% P = 0.31, respectively). Regression analysis between the two samples revealed significant positive correlation for morphologically normal and for LNV spermatozoa (r = 0.57 95% CI: 0.47-0.65 P < 0.0001 and r = 0.50 95% CI: 0.38-0.58 P < 0.0001, respectively).Conclusions: The significant positive correlation and absence of differences between two sperm samples evaluated after a time interval with respect to normal morphology and LNV spermatozoa indicated that MSOME seems reliable (at least for these two specific sperm forms) for analyzing semen. The present result supports the future use of MSOME as a routine method for semen analysis.

Are large-scale distributional shifts of the blue-winged macaw (Primolius maracana) related to climate change?

Aim To evaluate whether observed geographical shifts in the distribution of the blue-winged macaw (Primolius maracana) are related to ongoing processes of global climate change. This species is vulnerable to extinction and has shown striking range retractions in recent decades, withdrawing broadly from southern portions of its historical distribution. Its range reduction has generally been attributed to the effects of habitat loss; however, as this species has also disappeared from large forested areas, consideration of other factors that may act in concert is merited.Location Historical distribution of the blue-winged macaw in Brazil, eastern Paraguay and northern Argentina.Methods We used a correlative approach to test a hypothesis of causation of observed shifts by reduction of habitable areas mediated by climate change. We developed models of the ecological niche requirements of the blue-winged macaw, based on point-occurrence data and climate scenarios for pre-1950 and post-1950 periods, and tested model predictivity for anticipating geographical distributions within time periods. Then we projected each model to the other time period and compared distributions predicted under both climate scenarios to assess shifts of habitable areas across decades and to evaluate an explanation for observed range retractions.Results Differences between predicted distributions of the blue-winged macaw over the twentieth century were, in general, minor and no change in suitability of landscapes was predicted across large areas of the species' original range in different time periods. No tendency towards range retraction in the south was predicted, rather conditions in the southern part of the species' range tended to show improvement for the species.Main conclusions Our test permitted elimination of climate change as a likely explanation for the observed shifts in the distribution of the blue-winged macaw, and points rather to other causal explanations (e.g. changing regional land use, emerging diseases).

Bird attributes, plant characteristics, and seed dispersal of Pera glabrata (Schott, 1858), (Euphorbiaceae) in a disturbed cerrado area

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Survey of mid and large bodied mammals in Núcleo Caraguatatuba, Serra do Mar State Park, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecologia da paisagem: mapeamento da vegetação da Reserva Biológica da Serra do Japi, Jundiaí, SP, Brasil

Foi realizado o mapeamento da vegetação da Reserva Biológica (REBIO) Municipal da Serra do Japi, Jundiaí, SP, por meio de fotointerpretação analógica, em escala 1:30.000. O mapa foi digitalizado e transferido para computador pelo sistema de informação geográfica (Idrisi) e posteriormente para o programa Corel Draw. Foram identificadas, mapeadas e descritas oito unidades de paisagem (UP) sendo três antrópicas (solo exposto, campo antrópico e reflorestamento homogêneo) e cinco naturais (floresta estacional semidecidual montana dossel uniforme - microfanerófitos; floresta estacional semidecidual montana dossel uniforme - mesofanerófitos; floresta estacional semidecidual montana dossel emergente; floresta estacional semidecidual aluvial dossel emergente e refúgio montano arbustivo). As unidades naturais somaram 98,46% do total dos 2.071,20 ha da área, indicando que a Reserva vem cumprindo seu papel na preservação do ecossistema em questão. No entanto, como algumas unidades não tem expressiva representatividade na área, e como existe grande extensão de floresta no entorno da Reserva, sugere-se a ampliação e a transformação da mesma em uma unidade que contemple inclusive a visitação pública como forma de auxiliar no processo de conservação. Sugere-se que a área seja transformada em parque estadual, cujo nome poderia ser Parque Estadual da Serra do Japi.

Priority areas for the conservation of Atlantic forest large mammals

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da diversidade de Sardinella brasiliensis (Steindachner, 1879), na área entre Macaé (22º23'S) e Ilha de Santa Catarina (27º35'S): 1. Crescimento de dimensões corporais

The growth of body proportions of Sardinella brasiliensis was not homogeneous in the study area, between Macaé (RJ) and Santa Catarina Island (SC); the growth rates (K) of the von Bertalanffy growth curve were greater than growth rates for another áreas. In this area the biomass estimates for pelagic fish is poor, and near Cabo Frio occurs an upwelling zone. These facts permit the sardines to attain large lengths in this area. Between Rio de Janeiro and Florianópolis the growth rates were lower than in the northern part and Paranaguá Bay. on the other hand the biomass estimates for pelagic fish in Rio de Janeiro-Florianópolis region was very high, and in this zone the population density is high and the growth rates are small. Paranaguá Bay is a particular region because of its geographical and oceanographic conditons; this is a shelter region with different features and the sardines living there attain small length. In this area the growth rates are intermediary among growth rates for fishes from Macaé-Cabo Frio and Rio de Janeiro-Florianópolis regions. Therefore, the growth rates for sardines in southeast Brazilian proves to be dependent of the population density, food and oceanographic conditions.

Guiana dolphins, Sotalia guianensis (Cetacea: Delphinidae), in the Paranaguá Estuarine Complex: insights on the use of area based on the photo-identification technique

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)