137 research outputs found
Single-Shot Decoding of Linear Rate LDPC Quantum Codes with High Performance
We construct and analyze a family of low-density parity check (LDPC) quantum
codes with a linear encoding rate, polynomial scaling distance and efficient
decoding schemes. The code family is based on tessellations of closed,
four-dimensional, hyperbolic manifolds, as first suggested by Guth and
Lubotzky. The main contribution of this work is the construction of suitable
manifolds via finite presentations of Coxeter groups, their linear
representations over Galois fields and topological coverings. We establish a
lower bound on the encoding rate~k/n of~13/72 = 0.180... and we show that the
bound is tight for the examples that we construct. Numerical simulations give
evidence that parallelizable decoding schemes of low computational complexity
suffice to obtain high performance. These decoding schemes can deal with
syndrome noise, so that parity check measurements do not have to be repeated to
decode. Our data is consistent with a threshold of around 4% in the
phenomenological noise model with syndrome noise in the single-shot regime.Comment: 15 pages, 6 figure
Automatic PCB Defects Detection and Classification using Matlab
Abstract The importance of the Printed Circuit Board inspection process has been magnified by requirements of the modern manufacturing environment. In electronics mass production manufacturing facilities, an attempt is often to achieve 100% quality assurance
Efeito de concentrações de sacarose e de meio de cultura (8s) sobre a taxa de crescimento de e mandioca cultivar olho roxo (bgm 0036) conservadas in vitro.
A mandioca é uma cultura de grande na alimentação humana e animal, sendo que esta pode ser cultivada em várias regiões do país. Com o advento do melhoramento, diferentes cultivares foram desenvolvidas e, com isso, há uma necessidade tanto de manutenção destas quanto de multiplicação em larga escala das mesmas. O objetivo deste trabalho foi avaliar concentrações 1/1, ½ e ¼ de meio 8S combinados com diferentes doses de sacarose na taxa de crescimento de mandioca cultivada in vitro, avaliando-se altura de plantas, número de folhas vivas e mortas, número de ápices vivos e mortos e número de gemas. Os explantes apresentaram maior desempenho em meio de cultura com ¼ de 8S e uma concentração de 0,4 g.L-1 de sacarose. Contudo, a taxa de sobrevivência para manutenção do material foi melhor quando utilizou-se o meio 8S em sua composição original, na concentração de 0,4 g.L-1
Deadly disasters in southeastern South America: flash floods and landslides of February 2022 in Petrópolis, Rio de Janeiro
On 15 February 2022, the city of Petrópolis in the highlands of the state of Rio de Janeiro, Brazil, received an unusually high
volume of rain within 3 h (258 mm), generated by a strongly
invigorated mesoscale convective system. It resulted in flash floods and
subsequent landslides that caused the deadliest landslide disaster recorded
in Petrópolis, with 231 fatalities. In this paper, we analyzed the root
causes and the key triggering factors of this landslide disaster by
assessing the spatial relationship of landslide occurrence with various
environmental factors. Rainfall data were retrieved from 1977 to 2022 (a
combination of ground weather stations and the Climate Hazards Group
InfraRed Precipitation – CHIRPS). Remotely sensed data were used to map the landslide scars, soil moisture, terrain attributes, line-of-sight
displacement (land surface deformation), and urban sprawling (1985–2020).
The results showed that the average monthly rainfall for February 2022 was
200 mm, the heaviest recorded in Petrópolis since 1932. Heavy rainfall
was also recorded mostly in regions where the landslide occurred, according
to analyses of the rainfall spatial distribution. As for terrain, 23 % of slopes between 45–60∘ had landslide occurrences and east-facing
slopes appeared to be the most conducive for landslides as they recorded
landslide occurrences of about 9 % to 11 %. Regarding the soil moisture, higher variability was found in the lower altitude (842 m) where the residential area is concentrated. Based on our land deformation assessment, the area is geologically stable, and the landslide occurred only in the thin
layer at the surface. Out of the 1700 buildings found in the region of
interest, 1021 are on the slope between 20 to 45∘ and about 60 houses were directly affected by the landslides. As such, we conclude that the heavy rainfall was not the only cause responsible for the catastrophic event of 15 February 2022; a combination of unplanned urban growth on slopes between 45–60∘, removal of vegetation, and the absence of inspection were also expressive driving forces of this disaster.</p
Avaliação de propostas de candidatos a prefeitos em relação aos riscos de desastres naturais
Genetic structure from the oldest Jatropha germplasm bank of Brazil and contribution for the genetic improvement
High blood pressure in school children: prevalence and risk factors
BACKGROUND: The purpose of this study was to determine the prevalence of high blood pressure (HBP) and associated risk factors in school children 8 to 13 years of age. METHODS: Elementary school children (n = 1,066) were examined. Associations between HBP, body mass index (BMI), gender, ethnicity, and acanthosis nigricans (AN) were investigated using a school based cross-sectional study. Blood pressure was measured and the 95(th )percentile was used to determine HBP. Comparisons between children with and without HBP were utilized. The crude and multiple logistic regression adjusted odds ratios were used as measures of association. RESULTS: Females, Hispanics, overweight children, and children with AN had an increased likelihood of HBP. Overweight children (BMI ≥ 85(th )percentile) and those with AN were at least twice as likely to present with HBP after controlling for confounding factors. CONCLUSION: Twenty one percent of school children had HBP, especially the prevalence was higher among the overweight and Hispanic group. The association identified here can be used as independent markers for increased likelihood of HBP in children
Avaliação das cultivares de bananeira Prata-Anã, Thap Maeo e Caipira em diferentes sistemas de plantio no norte de Minas Gerais
Caryocar brasiliense supercritical CO2 extract possesses antimicrobial and antioxidant properties useful for personal care products
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