Alexandr FG | Moscow State Technical University (original) (raw)

Papers by Alexandr FG

We present an elementary proof of an a priori estimate of Bourgain for a general class of multipl... more We present an elementary proof of an a priori estimate of Bourgain for a general class of multipliers on a circle using an extension of methods developed in our previous work. The main tool is a suitable version of a counting argument of Zygmund for unbounded regions.

Communications in Mathematical Physics, 1998

We obtain a simple recursive presentation of the tautological (κ, ψ, and λ) classes on the moduli... more We obtain a simple recursive presentation of the tautological (κ, ψ, and λ) classes on the moduli space of curves in genus 000 and 111 in terms of boundary strata (graphs). We derive differential equations for the generating functions for their intersection numbers which allow us to prove a simple relationship between the genus zero and genus one potentials. As an application, we describe the moduli space of normalized, restricted, rank one cohomological field theories in genus one in coordinates which are additive under taking tensor products. Our results simplify and generalize those of Kaufmann, Manin, and Zagier.

The objective of this study was to perform QTL mapping on swine chromosome 6 (SSC6) associated wi... more The objective of this study was to perform QTL mapping on swine chromosome 6 (SSC6) associated with meat quality traits. The F2 population was produced by outbred crossing using two native Brazilian breed Piau sires with 18 commercial dams (Landrace x Large White). A total of 557 F2 animals were genotyped for 13 microsatellite markers. The traits evaluated on the F2 population were: pH evaluated at 45 minutes and at 24 hours post-morten (pH45, pHu, respectively), drip loss (DL), cooking loss (CL), total loss (TL), intramuscular fat content (IMF), objective tenderness (OT) and muscle color Hunter Lab system measurements: lightness (L), redness (A), yellowness (B), hue angle (h) and chroma (c). Data were analyzed by multiple regression developed for outbred lines crosses, using QTL Express software. Significant QTL were detected for pH45 and DL traits, and a suggestive QTL for DL. QTLs were not found for any other traits. The traits pH45 and DL may be under the influence of a gene or gene group located about 76, 88 and 97 cM. At the suggestive F-statistics regions, more markers should be included, in order to verify if they are real QTLs.

The Mixed Raster Content (MRC) document compression standard (ITU T.44) specifies a multi-layer m... more The Mixed Raster Content (MRC) document compression standard (ITU T.44) specifies a multi-layer multi-resolution representation of a compound document. The model is very efficient for representing sharp text and graphics onto a background. However, since the mask layer is binary, it is difficult to deal with scanned data and soft edges. The edge transitions do not fully belong to the foreground neither to the background, and cause some "halo" to the object edges using the MRC model. This paper presents an algorithm that builds an edge sharpening map and iteratively parameterizes the original edge "softness" at the encoder. The generated map and the "softness" parameters are, then, used to reconstruct the original soft edges at the decoder. Experimental results are presented, showing that the method can yield 1.5 dB gains in PSNR, in the compression ranges of interest.

... U r(t) = L s(U)(t, o: (U)) exp{j27rj(U)t} + w(t), (1) u=1 where w(t) is a zero-mean circularl... more ... U r(t) = L s(U)(t, o: (U)) exp{j27rj(U)t} + w(t), (1) u=1 where w(t) is a zero-mean circularly symmetric white Gaus sian noise process with power spectral density (PSD) 2No (No is assumed to be known at the receiver), j(u) is the difference between the carrier frequency of user U ...

Archive for Rational Mechanics and Analysis, 2000

We consider initial layers and uniqueness of weak entropy solutions to hyperbolic conservation la... more We consider initial layers and uniqueness of weak entropy solutions to hyperbolic conservation laws through the scalar case. The entropy solutions we address assume their initial data only in the sense of weak-star in L ∞ as t→0+ and satisfy the entropy inequality in the sense of distributions for t>0. We prove that, if the flux function has weakly genuine nonlinearity, then the entropy solutions are always unique and the initial layers do not appear. We also discuss applications to the zero relaxation limit for hyperbolic systems of conservation laws with relaxation.

Page 1. A Constructive Genetic Algorithm for the Linear Gate Assignment Problem Alexandre César M... more Page 1. A Constructive Genetic Algorithm for the Linear Gate Assignment Problem Alexandre César Muniz de Oliveira Luiz Antonio Nogueira Lorena DEINF - Universidade Federal do Maranhão Campus Bacanga, São Luís, MA, Brasil acmo@deinf.ufma.br ...

BMC Microbiology, 2010

Background Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants p... more Background Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants present in many countries in Asia, Africa and America, but not in the Mediterranean area. There are three types of Citrus Bacterial Canker, named A, B, and C that have different genotypes and posses variation in host range within citrus species. The causative agent for type A CBC is Xanthomonas citri subsp. citri, while Xanthomonas fuscans subsp. aurantifolii, strain B causes type B CBC and Xanthomonas fuscans subsp. aurantifolii strain C causes CBC type C. The early and accurate identification of those bacteria is essential for the protection of the citrus industry. Detection methods based on bacterial isolation, antibodies or polymerase chain reaction (PCR) have been developed previously; however, these approaches may be time consuming, laborious and, in the case of PCR, it requires expensive laboratory equipment. Loop-mediated isothermal amplification (LAMP), which is a novel isothermal DNA amplification technique, is sensitive, specific, fast and requires no specialized laboratory equipment. Results A loop-mediated isothermal amplification assay for the diagnosis of Citrus Bacterial Canker (CBC-LAMP) was developed and evaluated. DNA samples were obtained from infected plants or cultured bacteria. A typical ladder-like pattern on gel electrophoresis was observed in all positive samples in contrast to the negative controls. In addition, amplification products were detected by visual inspection using SYBRGreen and using a lateral flow dipstick, eliminating the need for gel electrophoresis. The sensitivity and specificity of the assay were evaluated in different conditions and using several sample sources which included purified DNA, bacterium culture and infected plant tissue. The sensitivity of the CBC-LAMP was 10 fg of pure Xcc DNA, 5 CFU in culture samples and 18 CFU in samples of infected plant tissue. No cross reaction was observed with DNA of other phytopathogenic bacteria. The assay was capable of detecting CBC-causing strains from several geographical origins and pathotypes. Conclusions The CBC-LAMP technique is a simple, fast, sensitive and specific method for the diagnosis of Citrus Bacterial Canker. This method can be useful in the phytosanitary programs of the citrus industry worldwide.

The Electronic Journal of Combinatorics, 2006

A homomorphism from an oriented graph G to an oriented graph H is a mapping ϕ from the set of ver... more A homomorphism from an oriented graph G to an oriented graph H is a mapping ϕ from the set of vertices of G to the set of vertices of H such that

Atmospheric and oceanic wakes past islands or mountains present, or not, similarities with the vo... more Atmospheric and oceanic wakes past islands or mountains present, or not, similarities with the von-Karman vortex street. Observations amd rotating-tank experiments show that cyclone-anticyclone asymmetry may occur, and that shedding frequencies (Strouhal numbers) may differ. Using direct numerical simulation and linear stability analysis, we explain and interpret these observations and characterize the dynamics of a single shallow layer of rotating fluid downstream a cylindrical obstacle. Especially, we show that while the wake is symmetric in the quasi-geostrophic (QG) regime, the frontal-geostrophic (FG) regime favors the emergence of anticyclones. This selection takes place at the linear stage and is exacerbated in subsequent, nonlinear stages. Furthermore we find that the wake emerges from a genuine, global instability only in a certain region of the parameter space, including the QG regime. Outside of this region, and especially in the FG regime, the wake emerges only as a response to upstream noise. However very low levels of upstream noise are sufficient to trigger a fully nonlinear wake with a well-defined shedding frequency.

We present an elementary proof of an a priori estimate of Bourgain for a general class of multipl... more We present an elementary proof of an a priori estimate of Bourgain for a general class of multipliers on a circle using an extension of methods developed in our previous work. The main tool is a suitable version of a counting argument of Zygmund for unbounded regions.

Communications in Mathematical Physics, 1998

We obtain a simple recursive presentation of the tautological (κ, ψ, and λ) classes on the moduli... more We obtain a simple recursive presentation of the tautological (κ, ψ, and λ) classes on the moduli space of curves in genus 000 and 111 in terms of boundary strata (graphs). We derive differential equations for the generating functions for their intersection numbers which allow us to prove a simple relationship between the genus zero and genus one potentials. As an application, we describe the moduli space of normalized, restricted, rank one cohomological field theories in genus one in coordinates which are additive under taking tensor products. Our results simplify and generalize those of Kaufmann, Manin, and Zagier.

The objective of this study was to perform QTL mapping on swine chromosome 6 (SSC6) associated wi... more The objective of this study was to perform QTL mapping on swine chromosome 6 (SSC6) associated with meat quality traits. The F2 population was produced by outbred crossing using two native Brazilian breed Piau sires with 18 commercial dams (Landrace x Large White). A total of 557 F2 animals were genotyped for 13 microsatellite markers. The traits evaluated on the F2 population were: pH evaluated at 45 minutes and at 24 hours post-morten (pH45, pHu, respectively), drip loss (DL), cooking loss (CL), total loss (TL), intramuscular fat content (IMF), objective tenderness (OT) and muscle color Hunter Lab system measurements: lightness (L), redness (A), yellowness (B), hue angle (h) and chroma (c). Data were analyzed by multiple regression developed for outbred lines crosses, using QTL Express software. Significant QTL were detected for pH45 and DL traits, and a suggestive QTL for DL. QTLs were not found for any other traits. The traits pH45 and DL may be under the influence of a gene or gene group located about 76, 88 and 97 cM. At the suggestive F-statistics regions, more markers should be included, in order to verify if they are real QTLs.

The Mixed Raster Content (MRC) document compression standard (ITU T.44) specifies a multi-layer m... more The Mixed Raster Content (MRC) document compression standard (ITU T.44) specifies a multi-layer multi-resolution representation of a compound document. The model is very efficient for representing sharp text and graphics onto a background. However, since the mask layer is binary, it is difficult to deal with scanned data and soft edges. The edge transitions do not fully belong to the foreground neither to the background, and cause some "halo" to the object edges using the MRC model. This paper presents an algorithm that builds an edge sharpening map and iteratively parameterizes the original edge "softness" at the encoder. The generated map and the "softness" parameters are, then, used to reconstruct the original soft edges at the decoder. Experimental results are presented, showing that the method can yield 1.5 dB gains in PSNR, in the compression ranges of interest.

... U r(t) = L s(U)(t, o: (U)) exp{j27rj(U)t} + w(t), (1) u=1 where w(t) is a zero-mean circularl... more ... U r(t) = L s(U)(t, o: (U)) exp{j27rj(U)t} + w(t), (1) u=1 where w(t) is a zero-mean circularly symmetric white Gaus sian noise process with power spectral density (PSD) 2No (No is assumed to be known at the receiver), j(u) is the difference between the carrier frequency of user U ...

Archive for Rational Mechanics and Analysis, 2000

We consider initial layers and uniqueness of weak entropy solutions to hyperbolic conservation la... more We consider initial layers and uniqueness of weak entropy solutions to hyperbolic conservation laws through the scalar case. The entropy solutions we address assume their initial data only in the sense of weak-star in L ∞ as t→0+ and satisfy the entropy inequality in the sense of distributions for t>0. We prove that, if the flux function has weakly genuine nonlinearity, then the entropy solutions are always unique and the initial layers do not appear. We also discuss applications to the zero relaxation limit for hyperbolic systems of conservation laws with relaxation.

Page 1. A Constructive Genetic Algorithm for the Linear Gate Assignment Problem Alexandre César M... more Page 1. A Constructive Genetic Algorithm for the Linear Gate Assignment Problem Alexandre César Muniz de Oliveira Luiz Antonio Nogueira Lorena DEINF - Universidade Federal do Maranhão Campus Bacanga, São Luís, MA, Brasil acmo@deinf.ufma.br ...

BMC Microbiology, 2010

Background Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants p... more Background Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants present in many countries in Asia, Africa and America, but not in the Mediterranean area. There are three types of Citrus Bacterial Canker, named A, B, and C that have different genotypes and posses variation in host range within citrus species. The causative agent for type A CBC is Xanthomonas citri subsp. citri, while Xanthomonas fuscans subsp. aurantifolii, strain B causes type B CBC and Xanthomonas fuscans subsp. aurantifolii strain C causes CBC type C. The early and accurate identification of those bacteria is essential for the protection of the citrus industry. Detection methods based on bacterial isolation, antibodies or polymerase chain reaction (PCR) have been developed previously; however, these approaches may be time consuming, laborious and, in the case of PCR, it requires expensive laboratory equipment. Loop-mediated isothermal amplification (LAMP), which is a novel isothermal DNA amplification technique, is sensitive, specific, fast and requires no specialized laboratory equipment. Results A loop-mediated isothermal amplification assay for the diagnosis of Citrus Bacterial Canker (CBC-LAMP) was developed and evaluated. DNA samples were obtained from infected plants or cultured bacteria. A typical ladder-like pattern on gel electrophoresis was observed in all positive samples in contrast to the negative controls. In addition, amplification products were detected by visual inspection using SYBRGreen and using a lateral flow dipstick, eliminating the need for gel electrophoresis. The sensitivity and specificity of the assay were evaluated in different conditions and using several sample sources which included purified DNA, bacterium culture and infected plant tissue. The sensitivity of the CBC-LAMP was 10 fg of pure Xcc DNA, 5 CFU in culture samples and 18 CFU in samples of infected plant tissue. No cross reaction was observed with DNA of other phytopathogenic bacteria. The assay was capable of detecting CBC-causing strains from several geographical origins and pathotypes. Conclusions The CBC-LAMP technique is a simple, fast, sensitive and specific method for the diagnosis of Citrus Bacterial Canker. This method can be useful in the phytosanitary programs of the citrus industry worldwide.

The Electronic Journal of Combinatorics, 2006

A homomorphism from an oriented graph G to an oriented graph H is a mapping ϕ from the set of ver... more A homomorphism from an oriented graph G to an oriented graph H is a mapping ϕ from the set of vertices of G to the set of vertices of H such that

Atmospheric and oceanic wakes past islands or mountains present, or not, similarities with the vo... more Atmospheric and oceanic wakes past islands or mountains present, or not, similarities with the von-Karman vortex street. Observations amd rotating-tank experiments show that cyclone-anticyclone asymmetry may occur, and that shedding frequencies (Strouhal numbers) may differ. Using direct numerical simulation and linear stability analysis, we explain and interpret these observations and characterize the dynamics of a single shallow layer of rotating fluid downstream a cylindrical obstacle. Especially, we show that while the wake is symmetric in the quasi-geostrophic (QG) regime, the frontal-geostrophic (FG) regime favors the emergence of anticyclones. This selection takes place at the linear stage and is exacerbated in subsequent, nonlinear stages. Furthermore we find that the wake emerges from a genuine, global instability only in a certain region of the parameter space, including the QG regime. Outside of this region, and especially in the FG regime, the wake emerges only as a response to upstream noise. However very low levels of upstream noise are sufficient to trigger a fully nonlinear wake with a well-defined shedding frequency.