WorldWideScience

Sample records for burgers vector

  1. Analysis of stress-induced Burgers vector anisotropy in pressurized tube specimens of irradiated ferritic-martensitic steel: JLF-1

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States); Shibayama, T. [Univ. of Hokkaido, Oarai, Ibaraki (Japan). Inst. for Materials Research

    1998-09-01

    A procedure for determining the Burgers vector anisotropy in irradiated ferritic steels allowing identification of all a<100> and all a/2<111> dislocations in a region of interest is applied to a pressurized tube specimen of JLF-1 irradiated at 430 C to 14.3 {times} 10{sup 22} n/cm{sup 2} (E > 0.1 MeV) or 61 dpa. Analysis of micrographs indicates large anisotropy in Burgers vector populations develop during irradiation creep.

  2. Direct observation of the coalescence process between nanoscale dislocation loops with different Burgers vectors

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, K., E-mail: arakawak@uhvem.osaka-u.ac.jp [Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); CREST, JST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Amino, T.; Mori, H. [Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

    2011-01-15

    The dynamic behavior of nanoscale prismatic dislocation loops can significantly affect the microstructural variation in crystalline materials upon processes such as plastic deformation and high-energy particle irradiation. Using in situ transmission electron microscopy, this study experimentally demonstrates a reaction which follows the collision between two loops with different Burgers vectors in {alpha}-iron. Even after the formation of the junction, the reaction progresses further, unlike conventional reactions between dislocations of macroscopic length, and the larger loop finally absorbs the smaller one.

  3. Dislocation Loops with a Burgers Vector Produced by 1 MeV Electron Irradiation in FCC Copper-Nickel

    DEFF Research Database (Denmark)

    Leffers, Torben; Barlow, P.

    1975-01-01

    Dislocation loops with Burgers vector a are formed in Cu-Ni alloys during 1 MeV electron irradiation in a high-voltage electron microscope at 350°-400°C. The dislocation loops are of interstitial type and pure edge in character with line vectors. Some of the loops are seen to dissociate into loop...

  4. The Weighted Burgers Vector: a new quantity for constraining dislocation densities and types using electron backscatter diffraction on 2D sections through crystalline materials.

    Science.gov (United States)

    Wheeler, J; Mariani, E; Piazolo, S; Prior, D J; Trimby, P; Drury, M R

    2009-03-01

    The Weighted Burgers Vector (WBV) is defined here as the sum, over all types of dislocations, of [(density of intersections of dislocation lines with a map) x (Burgers vector)]. Here we show that it can be calculated, for any crystal system, solely from orientation gradients in a map view, unlike the full dislocation density tensor, which requires gradients in the third dimension. No assumption is made about gradients in the third dimension and they may be non-zero. The only assumption involved is that elastic strains are small so the lattice distortion is entirely due to dislocations. Orientation gradients can be estimated from gridded orientation measurements obtained by EBSD mapping, so the WBV can be calculated as a vector field on an EBSD map. The magnitude of the WBV gives a lower bound on the magnitude of the dislocation density tensor when that magnitude is defined in a coordinate invariant way. The direction of the WBV can constrain the types of Burgers vectors of geometrically necessary dislocations present in the microstructure, most clearly when it is broken down in terms of lattice vectors. The WBV has three advantages over other measures of local lattice distortion: it is a vector and hence carries more information than a scalar quantity, it has an explicit mathematical link to the individual Burgers vectors of dislocations and, since it is derived via tensor calculus, it is not dependent on the map coordinate system. If a sub-grain wall is included in the WBV calculation, the magnitude of the WBV becomes dependent on the step size but its direction still carries information on the Burgers vectors in the wall. The net Burgers vector content of dislocations intersecting an area of a map can be simply calculated by an integration round the edge of that area, a method which is fast and complements point-by-point WBV calculations.

  5. Burgers turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Bec, Jeremie [Laboratoire Cassiopee UMR6202, CNRS, OCA, BP4229, 06304 Nice Cedex 4 (France)]. E-mail: jeremie.bec@obs-nice.fr; Khanin, Konstantin [Department of Mathematics, University of Toronto, Toronto, Ont., M5S 3G3 (Canada)]. E-mail: khanin@math.toronto.edu

    2007-08-15

    The last decades witnessed a renewal of interest in the Burgers equation. Much activities focused on extensions of the original one-dimensional pressureless model introduced in the thirties by the Dutch scientist J.M. Burgers, and more precisely on the problem of Burgers turbulence, that is the study of the solutions to the one- or multi-dimensional Burgers equation with random initial conditions or random forcing. Such work was frequently motivated by new emerging applications of Burgers model to statistical physics, cosmology, and fluid dynamics. Also Burgers turbulence appeared as one of the simplest instances of a nonlinear system out of equilibrium. The study of random Lagrangian systems, of stochastic partial differential equations and their invariant measures, the theory of dynamical systems, the applications of field theory to the understanding of dissipative anomalies and of multiscaling in hydrodynamic turbulence have benefited significantly from progress in Burgers turbulence. The aim of this review is to give a unified view of selected work stemming from these rather diverse disciplines.

  6. Burger Jihad

    DEFF Research Database (Denmark)

    Rytter, Mikkel

    2016-01-01

    Based on a number of ‘burger episodes’ during ten days of itikaf at a Sufi lodge in Pakistan, this article discusses the difficulties of religious self-cultivation among young Muslim pilgrims from Denmark. The focus on food and eating is not only used to discuss how religious brotherhoods and spi...... and spiritual kinship are created and maintained, but also becomes a prism to discuss emic conceptualizations of the nafs, the lower self, as well as how the jihad of dedicated Sufi Muslims is tested by fatal attractions of various kinds – in this case, in the guise of tasty burgers....

  7. Classical and Quantum Burgers Fluids: A Challenge for Group Analysis

    Directory of Open Access Journals (Sweden)

    Philip Broadbridge

    2015-10-01

    Full Text Available The most general second order irrotational vector field evolution equation is constructed, that can be transformed to a single equation for the Cole–Hopf potential. The exact solution to the radial Burgers equation, with constant mass influx through a spherical supply surface, is constructed. The complex linear Schrödinger equation is equivalent to an integrable system of two coupled real vector equations of Burgers type. The first velocity field is the particle current divided by particle probability density. The second vector field gives a complex valued correction to the velocity that results in the correct quantum mechanical correction to the kinetic energy density of the Madelung fluid. It is proposed how to use symmetry analysis to systematically search for other constrained potential systems that generate a closed system of vector component evolution equations with constraints other than irrotationality.

  8. Multidimensional Potential Burgers Turbulence

    Science.gov (United States)

    Boritchev, Alexandre

    2016-03-01

    We consider the multidimensional generalised stochastic Burgers equation in the space-periodic setting: partial {u}/partial t+(nabla f({u}) \\cdot nabla) {u}-ν Δ {u}= nabla η, quad t ≥ 0, {x} in{T}^d=({R}/ {Z})^d, under the assumption that u is a gradient. Here f is strongly convex and satisfies a growth condition, ν is small and positive, while η is a random forcing term, smooth in space and white in time. For solutions u of this equation, we study Sobolev norms of u averaged in time and in ensemble: each of these norms behaves as a given negative power of ν. These results yield sharp upper and lower bounds for natural analogues of quantities characterising the hydrodynamical turbulence, namely the averages of the increments and of the energy spectrum. These quantities behave as a power of the norm of the relevant parameter, which is respectively the separation ℓ in the physical space and the wavenumber k in the Fourier space. Our bounds do not depend on the initial condition and hold uniformly in {ν}. We generalise the results obtained for the one-dimensional case in [10], confirming the physical predictions in [4, 30]. Note that the form of the estimates does not depend on the dimension: the powers of {ν, |{{k}}|, ℓ} are the same in the one- and the multi-dimensional setting.

  9. Solution and transcritical bifurcation of Burgers equation

    Institute of Scientific and Technical Information of China (English)

    Tang Jia-Shi; Zhao Ming-Hua; Han Feng; Zhang Liang

    2011-01-01

    Burgers equation is reduced into a first-order ordinary differential equation by using travelling wave transformation and it has typical bifurcation characteristics. We can obtain many exact solutions of the Burgers equation, discuss its transcritical bifurcation and control dynamical behaviours by extending the stable region. The transcritical bifurcation exists in the (2 + 1)-dimensional Burgers equation.

  10. Vectores

    OpenAIRE

    2016-01-01

    Documento que contiene la explicación sobre las temáticas de Sistemas coordenados, Cantidades vectoriales y escalares, Algunas propiedades de los vectores, Componentes de un vector y vectores unitarios

  11. Vectors

    DEFF Research Database (Denmark)

    Boeriis, Morten; van Leeuwen, Theo

    2017-01-01

    This article revisits the concept of vectors, which, in Kress and van Leeuwen’s Reading Images (2006), plays a crucial role in distinguishing between ‘narrative’, action-oriented processes and ‘conceptual’, state-oriented processes. The use of this concept in image analysis has usually focused...... on the most salient vectors, and this works well, but many images contain a plethora of vectors, which makes their structure quite different from the linguistic transitivity structures with which Kress and van Leeuwen have compared ‘narrative’ images. It can also be asked whether facial expression vectors...... should be taken into account in discussing ‘reactions’, which Kress and van Leeuwen link only to eyeline vectors. Finally, the question can be raised as to whether actions are always realized by vectors. Drawing on a re-reading of Rudolf Arnheim’s account of vectors, these issues are outlined...

  12. Wat doen burgers in de participatiesamenleving?

    NARCIS (Netherlands)

    Kerstholt, J.H.; Paradies, G.

    2014-01-01

    Eén van de centrale gevolgen van de transitie van verzorgingsstaat naar participatiesamenleving is dat burgers een actievere bijdrage aan het publieke belang moeten leveren. Is dit een haalbaar streven?

  13. Integrable Couplings of the Coupled Burgers Hierarchy

    Institute of Scientific and Technical Information of China (English)

    XIATie-Cheng; CHENXiao-Hong; CHENDeng-Yuan; ZHANGYu-Feng

    2004-01-01

    In this letter, a new loop algebra G is constructed, from which a new isospectral problem is established. It follows that integrable couplings of the well-known coupled Burgers hierarchy are obtained.

  14. THE EXACT SOLUTIONS OF THE BURGERS EQUATION AND HIGHER-ORDER BURGERS EQUATION IN (2+1) DIMENSIONS

    Institute of Scientific and Technical Information of China (English)

    BAI CHENG-LIN

    2001-01-01

    Some exact solutions of the Burgers equation and higher-order Burgers equation in (2+1) dimensions are obtained by using the extended homogeneous balance method. In these solutions there are solitary wave solutions, close formal solutions for the initial value problems of the Burgers equation and higher-order Burgers equation, and also infinitely many rational function solutions. All of the solutions contain some arbitrary functions that may be related to the symmetry properties of the Burgers equation and the higher-order Burgers equation in (2+1) dimensions.

  15. Generalized Cole–Hopf transformations for generalized Burgers equations

    Indian Academy of Sciences (India)

    B Mayil Vaganan; E Emily Priya

    2015-11-01

    A detailed review of the invention of Cole–Hopf transformations for the Burgers equation and all the subsequent works which include generalizations of the Burgers equation and the corresponding developments in Cole–Hopf transformations are documented.

  16. Modified Burgers' equation by the local discontinuous Galerkin method

    Institute of Scientific and Technical Information of China (English)

    Zhang Rong-Pei; Yu Xi-Jun; Zhao Guo-Zhong

    2013-01-01

    In this paper,we present the local discontinuous Galerkin method for solving Burgers' equation and the modified Burgers' equation.We describe the algorithm formulation and practical implementation of the local discontinuous Galerkin method in detail.The method is applied to the solution of the one-dimensional viscous Burgers' equation and two forms of the modified Burgers' equation.The numerical results indicate that the method is very accurate and efficient.

  17. Notes on Solutions to Burgers-type Equations

    Institute of Scientific and Technical Information of China (English)

    FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo

    2004-01-01

    A transformation is introduced and applied to solve Burgers-type equations,such as Burgers equation,Burgers-KdV equation and Burgers-KdV-Kuramoto equation.Many kinds of travelling wave solutions including solitary wave solution are obtained,and it is shown that this is a powerful method to solve nonlinear equations with odd-order and even-order derivatives simultaneously.

  18. Integrable version of Burgers equation in magnetohydrodynamics.

    Science.gov (United States)

    Olesen, P

    2003-07-01

    It is pointed out that for the case of (compressible) magnetohydrodynamics (MHD) with the fields v(y)(y,t) and Bx(y,t), one can have equations of the Burgers type which are integrable. We discuss the solutions. It turns out that the propagation of the nonlinear effects is governed by the initial velocity (as in Burgers case) as well as by the initial Alfvén velocity. Many results previously obtained for the Burgers equation can be transferred to the MHD case. We also discuss equipartition v(y)=+/-Bx. It is shown that an initial localized small scale magnetic field will end up in fields moving to the left and the right, thus transporting energy from smaller to larger distances.

  19. Algebraic dynamics solution and algebraic dynamics algorithm of Burgers equations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Algebraic dynamics solution and algebraic dynamics algorithm of nonlinear partial differential evolution equations in the functional space are applied to Burgers equation. The results indicate that the approach is effective for analytical solutions to Burgers equation, and the algorithm for numerical solutions of Burgers equation is more stable, with higher precision than other existing finite difference algo-rithms.

  20. Exact solutions and conservation laws of the system of two-dimensional viscous Burgers equations

    Science.gov (United States)

    Abdulwahhab, Muhammad Alim

    2016-10-01

    Fluid turbulence is one of the phenomena that has been studied extensively for many decades. Due to its huge practical importance in fluid dynamics, various models have been developed to capture both the indispensable physical quality and the mathematical structure of turbulent fluid flow. Among the prominent equations used for gaining in-depth insight of fluid turbulence is the two-dimensional Burgers equations. Its solutions have been studied by researchers through various methods, most of which are numerical. Being a simplified form of the two-dimensional Navier-Stokes equations and its wide range of applicability in various fields of science and engineering, development of computationally efficient methods for the solution of the two-dimensional Burgers equations is still an active field of research. In this study, Lie symmetry method is used to perform detailed analysis on the system of two-dimensional Burgers equations. Optimal system of one-dimensional subalgebras up to conjugacy is derived and used to obtain distinct exact solutions. These solutions not only help in understanding the physical effects of the model problem but also, can serve as benchmarks for constructing algorithms and validation of numerical solutions of the system of Burgers equations under consideration at finite Reynolds numbers. Independent and nontrivial conserved vectors are also constructed.

  1. Some new exact solutions to the Burgers-Fisher equation and generalized Burgers-Fisher equation

    Institute of Scientific and Technical Information of China (English)

    Jiang Lu; Guo Yu-Cui; Xu Shu-Jiang

    2007-01-01

    Some new exact solutions of the Burgers-Fisher equation and generalized Burgers-Fisher equation have been obtained by using the first integral method. These solutions include exponential function solutions, singular solitary wave solutions and some more complex solutions whose figures are given in the article. The result shows that the first integral method is one of the most effective approaches to obtain the solutions of the nonlinear partial differential equations.

  2. Rational Solutions in a Coupled Burgers System

    Institute of Scientific and Technical Information of China (English)

    HUANG Ling

    2006-01-01

    Three types of the rational solutions for a new coupled Burgers system are studied in detail in terms of the reduction and decoupled procedures. The first two types of rational solutions are singular and valid for one type of model parameter c>0, and another type of rational solutions is nonsingular at any type and valid for another type of model parameter c<0.

  3. Explicit solutions of Boussinesq-Burgers equation

    Institute of Scientific and Technical Information of China (English)

    Wang Zheng-Yan; Chen Ai-Hua

    2007-01-01

    Darboux transformation with multi-parameters for the Boussinesq-Burgers (B-B) equation is derived. For an application, some important explicit solutions of the B-B equation are obtained, including 2N-soliton solution and periodic solution. Finally, some elegant and interesting figures are plotted.

  4. Linearized Implicit Numerical Method for Burgers' Equation

    Science.gov (United States)

    Mukundan, Vijitha; Awasthi, Ashish

    2016-12-01

    In this work, a novel numerical scheme based on method of lines (MOL) is proposed to solve the nonlinear time dependent Burgers' equation. The Burgers' equation is semi discretized in spatial direction by using MOL to yield system of nonlinear ordinary differential equations in time. The resulting system of nonlinear differential equations is integrated by an implicit finite difference method. We have not used Cole-Hopf transformation which gives less accurate solution for very small values of kinematic viscosity. Also, we have not considered nonlinear solvers that are computationally costlier and take more running time.In the proposed scheme nonlinearity is tackled by Taylor series and the use of fully discretized scheme is easy and practical. The proposed method is unconditionally stable in the linear sense. Furthermore, efficiency of the proposed scheme is demonstrated using three test problems.

  5. Transient Growth in Stochastic Burgers Flows

    CERN Document Server

    Poças, Diogo

    2015-01-01

    This study considers the problem of the extreme behavior exhibited by solutions to Burgers equation subject to stochastic forcing. More specifically, we are interested in the maximum growth achieved by the "enstrophy" (the Sobolev $H^1$ seminorm of the solution) as a function of the initial enstrophy $\\mathcal{E}_0$, in particular, whether in the stochastic setting this growth is different than in the deterministic case considered by Ayala & Protas (2011). This problem is motivated by questions about the effect of noise on the possible singularity formation in hydrodynamic models. The main quantities of interest in the stochastic problem are the expected value of the enstrophy and the enstrophy of the expected value of the solution. The stochastic Burgers equation is solved numerically with a Monte Carlo sampling approach. By studying solutions obtained for a range of optimal initial data and different noise magnitudes, we reveal different solution behaviors and it is demonstrated that the two quantities ...

  6. Spontaneous Stochasticity and Anomalous Dissipation for Burgers Equation

    CERN Document Server

    Eyink, Gregory L

    2014-01-01

    We develop a Lagrangian approach to conservation-law anomalies in weak solutions of inviscid Burgers equation, motivated by previous work on the Kraichnan model of turbulent scalar advection. We show that the entropy solutions of Burgers possess Markov stochastic processes of (generalized) Lagrangian trajectories backward in time for which the Burgers velocity is a backward martingale. This property is shown to guarantee dissipativity of conservation-law anomalies for general convex functions of the velocity. The backward stochastic Burgers flows with these properties are not unique, however. We construct infinitely many such stochastic flows, both by a geometric construction and by the zero-noise limit of the Constantin-Iyer stochastic representation of viscous Burgers solutions. The latter proof yields the spontaneous stochasticity of Lagrangian trajectories backward in time for Burgers, at unit Prandtl number. It is conjectured that existence of a backward stochastic flow with the velocity as martingale is...

  7. Qualitative improvement of low meat beef burger using Aloe vera.

    Science.gov (United States)

    Soltanizadeh, Nafiseh; Ghiasi-Esfahani, Hossein

    2015-01-01

    Low meat beef burgers have found their niche in the food markets in developing countries because of their lower price. However, these burgers still lack an acceptable quality. This study investigates the effects of different concentrations of Aloe vera on the quality of this food product. For this purpose, beef burgers were produced with 0%, 1%, 3%, and 5% Aloe vera and the changes in their cooking parameters, lipid oxidation, texture, and appeal to consumers over 7days of refrigerated storage were evaluated. Results indicate that Aloe vera contributed to some extent to decreased cooking loss and diameter reduction in the burgers. Increased concentrations of Aloe vera led to improvements in the water absorption and texture of the burgers as well as their lipid stability. However, a concentration level of 3% led to the most acceptability of the product to the panelists. Finally, it was found that Aloe vera acts as a hydrocolloid and improves the quality of burgers.

  8. Discrete Element Simulation of Asphalt Mastics Based on Burgers Model

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; FENG Shi-rong; HU Xia-guang

    2007-01-01

    In order to investigate the viscoelastic performance of asphalt mastics, a micro-mechanical model for asphalt mastics was built by applying Burgers model to discrete element simulation and constructing Burgers contact model. Then the numerical simulation of creep tests was conducted, and results from the simulation were compared with the analytical solution for Burgers model. The comparision snowed that the two results agreed well with each other, suggesting that discrete element model based on Burgers model could be employed in the numerical simulation for asphalt mastics.

  9. Entropic lattice Boltzmann model for Burgers's equation.

    Science.gov (United States)

    Boghosian, Bruce M; Love, Peter; Yepez, Jeffrey

    2004-08-15

    Entropic lattice Boltzmann models are discrete-velocity models of hydrodynamics that possess a Lyapunov function. This feature makes them useful as nonlinearly stable numerical methods for integrating hydrodynamic equations. Over the last few years, such models have been successfully developed for the Navier-Stokes equations in two and three dimensions, and have been proposed as a new category of subgrid model of turbulence. In the present work we develop an entropic lattice Boltzmann model for Burgers's equation in one spatial dimension. In addition to its pedagogical value as a simple example of such a model, our result is actually a very effective way to simulate Burgers's equation in one dimension. At moderate to high values of viscosity, we confirm that it exhibits no trace of instability. At very small values of viscosity, however, we report the existence of oscillations of bounded amplitude in the vicinity of the shock, where gradient scale lengths become comparable with the grid size. As the viscosity decreases, the amplitude at which these oscillations saturate tends to increase. This indicates that, in spite of their nonlinear stability, entropic lattice Boltzmann models may become inaccurate when the ratio of gradient scale length to grid spacing becomes too small. Similar inaccuracies may limit the utility of the entropic lattice Boltzmann paradigm as a subgrid model of Navier-Stokes turbulence.

  10. Application of Extended Tanh Method to Generalized Burgers-type Equations

    Directory of Open Access Journals (Sweden)

    Hamid Panahipour

    2012-02-01

    Full Text Available In this paper, we show that the extended tanh method can be applied readily to generate exact soliton solutions of generalized forms of Burgers-KdV, Burgers-EW, two-dimensional Burgers-KdV and two-dimensional Burgers-EW equations.

  11. Spectrum and energy transfer in steady Burgers turbulence

    Science.gov (United States)

    Girimaji, Sharath S.; Zhou, YE

    1995-01-01

    The spectrum, energy transfer, and spectral interactions in steady Burgers turbulence are studied using numerically generated data. The velocity field is initially random and the turbulence is maintained steady by forcing the amplitude of a band of low wavenumbers to be invariant in time, while permitting the phase to change as dictated by the equation. The spectrum, as expected, is very different from that of Navier-Stokes turbulence. It is demonstrated that the far range of the spectrum scales as predicted by Burgers. Despite the difference in their spectra, in matters of the spectral energy transfer and triadic interactions Burgers turbulence is similar to Navier-Stokes turbulence.

  12. The superposition method in seeking the solitary wave solutions to the KdV-Burgers equation

    Indian Academy of Sciences (India)

    Yuanxi Xie; Jilashi Tang

    2006-03-01

    In this paper, starting from the careful analysis on the characteristics of the Burgers equation and the KdV equation as well as the KdV-Burgers equation, the superposition method is put forward for constructing the solitary wave solutions of the KdV-Burgers equation from those of the Burgers equation and the KdV equation. The solitary wave solutions for the KdV-Burgers equation are presented successfully by means of this method.

  13. On the decay of Burgers turbulence

    CERN Document Server

    Gurbatov, S N; Aurell, E; Frisch, U; Tóth, G

    1997-01-01

    This work is devoted to the decay ofrandom solutions of the unforced Burgers equation in one dimension in the limit of vanishing viscosity. The initial velocity is homogeneous and Gaussian with a spectrum proportional to $k^n$ at small wavenumbers $k$ and falling off quickly at large wavenumbers. In physical space, at sufficiently large distances, there is an ``outer region'', where the velocity correlation function preserves exactly its initial form (a power law) when $n$ is not an even integer. When $11$. A systematic derivation is given in which both the leading term and estimates of higher order corrections can be obtained. High-resolution numerical simulations are presented which support our findings.

  14. Solving the Burgers-KdV equation by a combination method%用组合法求解Burgers-KdV方程

    Institute of Scientific and Technical Information of China (English)

    谢元喜

    2009-01-01

    通过分析Burgers方程、KdV方程和Burgers-KdV方程的特点,提出了一种由Burgers方程的解和KdV方程的解构造Burgers-KdV方程解的组合法,并由此求得了Burgers-KdV方程的若干显式精确解.%In view of the analysis on the characteristics of the Burgers equation,KdV equation and Burgers-KdV equation,aacombination method is presented to construct the solutions of the Burgers-KdV equation by combining with those of the Burgers equation and KdV equation.As a result,many explicit and exact solutions of the Burgers-KdV equation are successfully derived by this technique.

  15. Stochastic heat and Burgers equations and their singularities. II. Analytical properties and limiting distributions

    Science.gov (United States)

    Davies, Ian M.; Truman, Aubrey; Zhao, Huaizhong

    2005-04-01

    We study the inviscid limit, μ →0, of the stochastic viscous Burgers equation, for the velocity field vμ(x,t), t >0, x εRd, (∂vμ/∂t)+(vμ.∇)vμ=-∇c(x,t)-ε∇k(x,t)Ẇt+(μ2/2)Δvμ, for small ε, with vμ(x,0)≡∇S0(x) for some given S0, Ẇt representing white noise. Here we use the Hopf-Cole transformation, vμ=-μ2∇lnuμ, where uμ satisfies the stochastic heat equation of Stratonovich-type and the Feynmac-Kac Truman-Zhao formula for uμ, where dutμ(x )=[(μ2/2)Δutμ(x)+μ-2c(x,t)utμ(x)]dt+εμ-2k(x,t)utμ(x)∘dWt, with u0μ(x)=T0(x)exp(-S0(x)/μ2), S0 as before and T0 a smooth positive function. In an earlier paper, Davies, Truman, and Zhao [J. Math. Phys. 43, 3293 (2002)], an exact solution of the stochastic viscous Burgers equation was used to show how the formal "blow-up" of the Burgers velocity field occurs on random shockwaves for the vμ =0 solution of Burgers equation coinciding with the caustics of a corresponding Hamiltonian system with classical flow map Φ. Moreover, the uμ =0 solution of the stochastic heat equation has its wavefront determined by the behavior of the Hamilton principal function of the corresponding stochastic mechanics. This led in particular to the level surface of the minimizing Hamilton-Jacobi function developing cusps at points corresponding to points of intersection of the corresponding prelevel surface with the precaustic, "pre" denoting the preimage under Φ determined algebraically. These results were primarily of a geometrical nature. In this paper we consider small ε and derive the shape of the random shockwave for the inviscid limit of the stochastic Burgers velocity field and also give the equation determining the random wavefront for the stochastic heat equation both correct to first order in ε. In the case c (x,t)=1/2xTΩ2x, ∇k(x,t)=-a(t), we obtain the exact random shockwave and prove that its shape is unchanged by the addition of noise, it merely being displaced by a random Brownian vector

  16. The Inviscid, Compressible and Rotational, 2D Isotropic Burgers and Pressureless Euler-Coriolis Fluids; Theory and Illustrations

    CERN Document Server

    Choquard, Philippe

    2013-01-01

    The coupling between dilatation and vorticity, two coexisting and fundamental processes in fluid dynamics is investigated here, in the simplest cases of inviscid 2D isotropic Burgers and pressureless Euler-Coriolis fluids respectively modeled by single vortices confined in compressible, local, inertial and global, rotating, environments. The field equations are established, inductively, starting from the equations of the characteristics solved with an initial Helmholtz decomposition of the velocity fields namely a vorticity free and a divergence free part and, deductively, by means of a canonical Hamiltonian Clebsch like formalism, implying two pairs of conjugate variables. Two vector valued fields are constants of the motion: the velocity field in the Burgers case and the momentum field per unit mass in the Euler-Coriolis one. Taking advantage of this property, a class of solutions for the mass densities of the fluids is given by the Jacobian of their sum with respect to the actual coordinates. Implementatio...

  17. Darboux Transformations and Soliton Solutions for Classical Boussinesq-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    XU Rui

    2008-01-01

    Two basic Darboux transformations of a spectral problem associated with a classical Boussinesq-Burgers equation are presented in this letter.They are used to generate new solutions of the classical Boussinesq-Burgers equation.

  18. Painlevé Analysis and Some Solutions of(2+1)-Dimensional Generalized Burgers Equations

    Institute of Scientific and Technical Information of China (English)

    HONG Ke-Zhu; WU B-in; CHEN Xian-Feng

    2003-01-01

    Burgers equation ut = 2uux + uxx describes a lot of phenomena in physics fields, and it has attracted much attention.In this paper,the Burgers equation is generalized to (2+1) dimensions.By means of the Painlev(e') analysis,the most generalized Painlev(e') integrable(2+1)-dimensional integrable Burgers systems are obtained.Some exact solutions of the generalized Burgers system are obtained via variable separation approach.

  19. Stokes' First Problem for an MHD Burgers Fluid

    Institute of Scientific and Technical Information of China (English)

    Masood Khan

    2013-01-01

    This work is related to the flow of a magnetohydrodynamic Burgers fluid.The flow of an incompressible conducting Burgers fluid in the presence of a uniform transverse magnetic field over a plate that is moved suddenly is considered.By the application of the Laplace and Fourier sine transforms techniques,the exact analytical expressions for the velocity field and associated shear stress are determined in simple forms.They are written as a sum of steady-state and transient solutions.The graphical results are plotted for different values of indispensable parameters and some interesting results are concluded.The corresponding solutions for the hydrodynamic Burgers fluid appear as the limiting cases of the obtained solutions.

  20. Politie en burgers : van informatie delen naar volwaardige samenwerking

    NARCIS (Netherlands)

    Kerstholt, J.H.; Vries, A. de; Mente, R.; Huis in 't Veld, M.A.A.

    2015-01-01

    De politieorganisatie maakt steeds meer gebruik van de capaciteit, kennis en kunde van burgers, vooral in de context van het Gebiedsgebonden Politiewerk (GGPW). Dit artikel geeft een overzicht van de huidige stand van zaken. Voor de verschillende vormen van participatie hebben we een indeling gemaak

  1. Mathematical modeling of fish burger baking using fractional calculus

    Directory of Open Access Journals (Sweden)

    Bainy Eduarda M.

    2017-01-01

    Full Text Available Tilapia (Oreochromis sp. is the most important and abundant fish species in Brazil due to its adaptability to different environments. The development of tilapia-based products could be an alternative in order to aggregate value and increase fish meat consumption. However, there is little information available on fishburger freezing and cooking in the literature. In this work, the mathematical modeling of the fish burger baking was studied. Previously to the baking process, the fishburgers were assembled in cylindrical shape of height equal to 8mm and diameter 100mm and then baked in an electrical oven with forced heat convection at 150ºC. A T-type thermocouple was inserted in the burger to obtain its temperature profile at the central position. In order to describe the temperature of the burger during the baking process, lumped-parameter models of integer and fractional order and also a nonlinear model due to heat capacity temperature dependence were considered. The burger physical properties were obtained from the literature. After proper parameter estimation tasks and statistical validation, the fractional order model could better describe the experimental temperature behavior, a value of 0.91±0.02 was obtained for the fractional order of the system with correlation coefficient of 0.99. Therefore, with the better temperature prediction, process control and economic optimization studies of the baking process can be conducted.

  2. On a stochastic Burgers equation with Dirichlet boundary conditions

    Directory of Open Access Journals (Sweden)

    Ekaterina T. Kolkovska

    2003-01-01

    Full Text Available We consider the one-dimensional Burgers equation perturbed by a white noise term with Dirichlet boundary conditions and a non-Lipschitz coefficient. We obtain existence of a weak solution proving tightness for a sequence of polygonal approximations for the equation and solving a martingale problem for the weak limit.

  3. Sensory profile of beef burger with reduced sodium content

    Directory of Open Access Journals (Sweden)

    Camila Barbosa Carvalho

    2015-05-01

    Full Text Available This study determined the sensory profile of three beef burger samples, namely, CON (control, F25 (25% sodium reduction and F50 (50% sodium reduction, based on the Quantitative Descriptive Analysis (QDA. The samples´ microbial, physical and chemical composition was evaluated. Twelve panelists were selected and trained using as criteria the panelists´ discrimination power, reproducibility and consensus. Eleven terms were generated by the method of network descriptors. The intensity of each descriptor in each sample was evaluated by unstructured scale of 9 cm. Data were analyzed by ANOVA, Duncan´s mean test and principal component analysis. The sensory profile shows that low sodium beef burgers had lower fat and salty flavor when compared to untreated control and greater flavor and spice aroma. The above proves that reducing sodium intake causes increased perception burger tasters when compared to the presence of spices in the product. Treatment with 50% sodium reduction obtained the best results for texture softness and appearance. There was no significant difference (p < 0.05 in the chemical composition of ash, protein and fat in all burgers. In the case of general sensory attributes, treatments with sodium reduction obtained higher intensities of the attributes evaluated, except for meat and salt flavors.

  4. Thermal inactivation of Salmonella spp. in pork burger patties.

    Science.gov (United States)

    Gurman, P M; Ross, T; Holds, G L; Jarrett, R G; Kiermeier, A

    2016-02-16

    Predictive models, to estimate the reduction in Escherichia coli O157:H7 concentration in beef burgers, have been developed to inform risk management decisions; no analogous model exists for Salmonella spp. in pork burgers. In this study, "Extra Lean" and "Regular" fat pork minces were inoculated with Salmonella spp. (Salmonella 4,[5],12,i:-, Salmonella Senftenberg and Salmonella Typhimurium) and formed into pork burger patties. Patties were cooked on an electric skillet (to imitate home cooking) to one of seven internal temperatures (46, 49, 52, 55, 58, 61, 64 °C) and Salmonella enumerated. A generalised linear logistic regression model was used to develop a predictive model for the Salmonella concentration based on the internal endpoint temperature. It was estimated that in pork mince with a fat content of 6.1%, Salmonella survival will be decreased by -0.2407log10 CFU/g for a 1 °C increase in internal endpoint temperature, with a 5-log10 reduction in Salmonella concentration estimated to occur when the geometric centre temperature reaches 63 °C. The fat content influenced the rate of Salmonella inactivation (P=0.043), with Salmonella survival increasing as fat content increased, though this effect became negligible as the temperature approached 62 °C. Fat content increased the time required for patties to achieve a specified internal temperature (P=0.0106 and 0.0309 for linear and quadratic terms respectively), indicating that reduced fat pork mince may reduce the risk of salmonellosis from consumption of pork burgers. Salmonella serovar did not significantly affect the model intercepts (P=0.86) or slopes (P=0.10) of the fitted logistic curve. This predictive model can be applied to estimate the reduction in Salmonella in pork burgers after cooking to a specific endpoint temperature and hence to assess food safety risk.

  5. A Pilot Study to Compare a Mushroom-Soy-Beef Burger to an All-Beef Burger in School Meals

    Science.gov (United States)

    Summers, Amber C.; Smith, Paul; Ezike, Adaora; Frutchey, Robin; Fahle, Jenna; DeVries, Eva; Taylor, Jarrett; Cheskin, Lawrence J.

    2015-01-01

    Purpose/Objectives: The purpose of this study was to determine if mushroom blended recipes are an acceptable option for use in the school food program. The palatability and acceptance of mushroom-soy-beef blend burgers among school-aged children was tested. Methods: Students in grades 2 through 8 were invited to participate in a taste test.…

  6. KdV-Burgers方程和 KdV-Burgers-Kuramoto方程的精确解%Exact solutions to the KdV-Burgers equation and KdV-Burgers-Kuramoto equation

    Institute of Scientific and Technical Information of China (English)

    谢元喜; 朱曙华

    2007-01-01

    基于对 KdV-Burgers方程和KdV-Burgers-Kuramoto方程特点的分析,提出了一种由Burgers方程的解和 KdV 方程的解通过线性叠加构造 KdV-Burgers 方程的解以及由 KdV 方程的解和Kuramoto-Sivashinsky 方程的解通过线性叠加构造 KdV-Burgers-Kuramoto 方程的解的方法,并用该法求得了 KdV-Burgers 方程和 KdV-Burgers-Kuramoto 方程的若干精确解.

  7. ASYMPTOTIC STABILITY OF RAREFACTION WAVE FOR GENERALIZED BURGERS EQUATION

    Institute of Scientific and Technical Information of China (English)

    Xu Yanling; Jiang Mina

    2005-01-01

    This paper is concerned with the stability of the rarefaction wave for the Burgers equation{ ut+f(u)x=μtαuxx, μ>0, x∈R, t>0, (Ⅰ)u|t=o = u0(x) →u± , x →∞ ,where 0 ≤α< 1/4q (q is determined by (2.2)). Roughly speaking, under the assumption that u- < u+, the authors prove the existence of the global smooth solution to the Cauchy problem (Ⅰ), also find the solution u(x, t) to the Cauchy problem (Ⅰ) satisfying sup |u(x, t)-x∈RuR(x/t)| → 0 as t →∞, where uR(x/t) is the rarefaction wave of the non-viscous Burgers equation ut + f(u)x = 0 with Riemann initial data u(x, 0) ={u_,x<0, u+, x>0.

  8. Convergence of a random walk method for the Burgers equation

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, S.

    1985-10-01

    In this paper we consider a random walk algorithm for the solution of Burgers' equation. The algorithm uses the method of fractional steps. The non-linear advection term of the equation is solved by advecting ''fluid'' particles in a velocity field induced by the particles. The diffusion term of the equation is approximated by adding an appropriate random perturbation to the positions of the particles. Though the algorithm is inefficient as a method for solving Burgers' equation, it does model a similar method, the random vortex method, which has been used extensively to solve the incompressible Navier-Stokes equations. The purpose of this paper is to demonstrate the strong convergence of our random walk method and so provide a model for the proof of convergence for more complex random walk algorithms; for instance, the random vortex method without boundaries.

  9. Moyal Noncommutative Integrability and the Burgers-KdV Mapping

    CERN Document Server

    Sedra, M B

    2005-01-01

    The Moyal momentum algebra is, once again, used to discuss some important aspects of NC integrable models and 2d conformal field theories. Among the results presented, we setup algebraic structures and makes useful convention notations leading to extract non trivial properties of the Moyal momentum algebra. We study also the Lax pair building mechanism for particular examples namely, the noncommutative KdV and Burgers systems. We show in a crucial step that these two systems are mapped to each others through a crucial mapping. This makes a strong constraint on the NC Burgers system which corresponds to linearizing its associated differential equation. From the conformal field theory point of view, this constraint equation is nothing but the analogue of the conservation law of the conformal current. We believe that this mapping might help to bring new insights towards understanding the integrability of noncommutative 2d-systems.

  10. Phase and precession evolution in the Burgers equation

    CERN Document Server

    Buzzicotti, Michele; Biferale, Luca; Bustamante, Miguel D

    2015-01-01

    We present a phenomenological study of the phase dynamics of the one-dimensional stochastically forced Burgers equation. We propose a way to link coherent structures in real space with the evolution of triads in Fourier space. The method is based on the idea that the real space structures can be associated with entangled correlations amongst the phase precession frequencies and the amplitude evolution of triads in Fourier space. As a result, triad precession frequencies show a non-Gaussian distribution with multiple peaks and fat tails, and there is a significant correlation between triad precession frequencies and amplitude growth. Links with dynamical systems approach are briefly discussed, such as the role of unstable critical points in state space. This analysis has been further developed for Burgers equation evolved on a fractal Fourier set. In this latter case, we observe a depletion of intermittency as a function of the fractal dimension $D$, and the simultaneous reduction of the correlation between th...

  11. Power Series Solution for Solving Nonlinear Burgers-Type Equations

    OpenAIRE

    López-Sandoval, E.; Mello, A.; Godina-Nava, J. J.; Samana, A. R.

    2015-01-01

    Power series solution method has been traditionally used to solve ordinary and partial linear differential equations. However, despite their usefulness the application of this method has been limited to this particular kind of equations. In this work we use the method of power series to solve nonlinear partial differential equations. The method is applied to solve three versions of nonlinear time-dependent Burgers-type differential equations in order to demonstrate its scope and applicability.

  12. Exact solutions of (3 + 1)-dimensional stochastic Burgers equation

    Energy Technology Data Exchange (ETDEWEB)

    Wang Tieying [Department of Applied Mathematics and Physics, Dalian Nationalities for University, Dalian 116600 (China)]. E-mail: wangty@dlnu.edu.cn; Ren Yonghong [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China); Zhao Yali [Department of Mathematics, Chaoyang Teachers College, Chaoyang 122000 (China)

    2006-08-15

    A generalized tan h function method is used for constructing exact travelling wave solutions of nonlinear stochastic partial differential equations. The main idea of this method is to take full advantage of the Riccati equation, which has more exact solutions. More Wick-type stochastic multiple soliton-like solutions and triangular periodic solutions are obtained for the (3 + 1)-dimensional Wick-type stochastic Burgers equation via Hermite transformation.

  13. The Burgers of Calais- on Performance and Experience Analysis

    DEFF Research Database (Denmark)

    Nagbøl, Søren Peter; Flensborg, Ingelise

    2015-01-01

    is reconciled. Based on a sculpture of AugustRodin (1840-1917) The Burgers of Calais which is on display at the Ny Carlsberg Glyptotek in Copenhagen, we will present how the educational activities as performativity can unfold and be reconciled with physically-based (gebildung) formation processes. Using various...... methodological grips, we prepare a didactic course reflected in an interpretational community where all the participants create awareness and new knowledge....

  14. Conservation laws of inviscid Burgers equation with nonlinear damping

    Science.gov (United States)

    Abdulwahhab, Muhammad Alim

    2014-06-01

    In this paper, the new conservation theorem presented in Ibragimov (2007) [14] is used to find conservation laws of the inviscid Burgers equation with nonlinear damping ut+g(u)ux+λh(u)=0. We show that this equation is both quasi self-adjoint and self-adjoint, and use these concepts to simplify conserved quantities for various choices of g(u) and h(u).

  15. Power Series Solution for Solving Nonlinear Burgers-Type Equations

    Directory of Open Access Journals (Sweden)

    E. López-Sandoval

    2015-01-01

    Full Text Available Power series solution method has been traditionally used to solve ordinary and partial linear differential equations. However, despite their usefulness the application of this method has been limited to this particular kind of equations. In this work we use the method of power series to solve nonlinear partial differential equations. The method is applied to solve three versions of nonlinear time-dependent Burgers-type differential equations in order to demonstrate its scope and applicability.

  16. Asymptotics for the Korteweg-de Vries-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    Nakao HAYASHI; Pavel I. NAUMKIN

    2006-01-01

    We study large time asymptotics of solutions to the Korteweg-de Vries-Burgers equation ut + uux - uxx + uxxx = 0, x ∈ R, t > 0.We are interested in the large time asymptotics for the case when the initial data have an arbitrary size. We prove that ifthe initial data u0 ∈ Hs (R) ∩L1 (R), where s > -1/2,then there exists a uniquesolution u (t,x) ∈ C∞ ((0, ∞);H∞ (R)) to the Cauchy problem for the Korteweg-de Vries-Burgers equation, which has asymptotics u (t) = t-1/2fM((·)t-1/2) + o(t-1/2) as t →∞, where fM is the self-similar solution for the Burgers equation. Moreover if xu0 (x) ∈ L1 (R),then the asymptotics are true u (t) = t-1/2fM((·)t-1/2) + O(t-1/2-γ),where γ∈ (0,1/2).

  17. Nanobioprobe for the Determination of Pork Adulteration in Burger Formulations

    Directory of Open Access Journals (Sweden)

    M. E. Ali

    2012-01-01

    Full Text Available We report the development of a swine-specific hybrid nanobioprobe through a covalent integration of a fluorophore-labeled 27-nucleotide AluI-fragment of swine cytochrome b gene to a 3 nm gold nanoparticle for the determination of pork adulteration in processed meat products. We tested the probe to estimate adulterated pork in ready-to-eat pork-spiked beef burgers. The probe quantitatively detected 1–100% spiked pork in burger formulations with ≥90% accuracy. A plot of observed fluorescence against the known concentration of AluI-digested pork DNA targets generated a concave curve, demonstrating a power relationship (y=2.956x0.509 with a regression coefficient (R2 of 0.986. No cross-species detection was found in a standard set of pork, beef, chicken, mutton, and chevon burgers. The method is suitable for the determination of very short-length nucleic acid targets which cannot be estimated by conventional and real-time PCR but are essential for the determination of microRNA in biodiagnostics and degraded DNA in forensic testing and food analysis.

  18. The generalized Burgers equation with and without a time delay

    Directory of Open Access Journals (Sweden)

    Nejib Smaoui

    2004-01-01

    Full Text Available We consider the generalized Burgers equation with and without a time delay when the boundary conditions are periodic with period 2π. For the generalized Burgers equation without a time delay, that is, ut=vuxx−uux+u+h(x, 00, u(0,t=u(2π,t, u(x,0=u0(x, a Lyapunov function method is used to show boundedness and uniqueness of a steady state solution and global stability of the equation. As for the generalized time-delayed Burgers equation, that is, ut(x,t=vuxx(x,t−u(x,t−τux(x,t+u(x,t, 00, u(0,t=u(2π,t, t>0, u(x,s=u0(x,s, 0

  19. The solid angle and the Burgers formula in the theory of gradient elasticity: Line integral representation

    Energy Technology Data Exchange (ETDEWEB)

    Lazar, Markus, E-mail: lazar@fkp.tu-darmstadt.de [Heisenberg Research Group, Department of Physics, Darmstadt University of Technology, Hochschulstr. 6, D-64289 Darmstadt (Germany); Po, Giacomo [Mechanical and Aerospace Engineering, University of California, Los Angeles, Los Angeles, CA 90095 (United States)

    2014-01-24

    A representation of the solid angle and the Burgers formula as line integral is derived in the framework of the theory of gradient elasticity of Helmholtz type. The gradient version of the Eshelby–deWit representation of the Burgers formula of a closed dislocation loop is given. Such a form is suitable for the numerical implementation in 3D dislocation dynamics (DD).

  20. Global solutions for 2D coupled Burgers-complex-Ginzburg-Landau equations

    Directory of Open Access Journals (Sweden)

    Hongjun Gao

    2015-12-01

    Full Text Available In this article, we study the periodic initial-value problem of the 2D coupled Burgers-complex-Ginzburg-Landau (Burgers-CGL equations. Applying the Brezis-Gallout inequality which is available in 2D case and establishing some prior estimates, we obtain the existence and uniqueness of a global solution under certain conditions.

  1. Direct perturbation method for perturbed complex Burgers equation

    Institute of Scientific and Technical Information of China (English)

    Cheng Xue-Ping; Lin Ji; Yao Jian-Ming

    2009-01-01

    So far, Lou's direct perturbation method has been applied successfully to solve the nonlinear Schrōdinger equa-tion(NLSE) hierarchy, such as the NLSE, the coupled NLSE, the critical NLSE, and the derivative NLSE. But to our knowledge, this method for other types of perturbed nonlinear evolution equations has still been lacking. In this paper, Lou's direct perturbation method is applied to the study of perturbed complex Burgers equation. By this method, we calculate not only the zero-order adiabatic solution, but also the first order modification.

  2. Bifurcation control in the Burgers-KdV equation

    Energy Technology Data Exchange (ETDEWEB)

    Maccari, Attilio [Technical Institute ' G. Cardano' , Piazza della Resistenza 1, 00015 Monterotondo (Rome) (Italy)], E-mail: solitone@yahoo.it

    2008-03-15

    We consider the bifurcation control for the forced Burgers-KdV equation by means of delay feedback linear terms. We use a perturbation method in order to find amplitude and phase modulation equations as well as external force-response and frequency-response curves. We observe in the resonance response a saddle-node bifurcation that leads to jump and hysteresis phenomena. We compare the uncontrolled and controlled systems and demonstrate that control terms can delay or remove the occurrence of the saddle-node bifurcation and reduce the amplitude peak of the resonant response.

  3. Linear stability of plane creeping Couette flow for Burgers fluid

    Science.gov (United States)

    Hu, Kai-Xin; Peng, Jie; Zhu, Ke-Qin

    2013-02-01

    It is well known that plane creeping Couette flow of UCM and Oldroy-B fluids are linearly stable. However, for Burges fluid, which includes UCM and Oldroyd-B fluids as special cases, unstable modes are detected in the present work. The wave speed, critical parameters and perturbation mode are studied for neutral waves. Energy analysis shows that the sustaining of perturbation energy in Poiseuille flow and Couette flow is completely different. At low Reynolds number limit, analytical solutions are obtained for simplified perturbation equations. The essential difference between Burgers fluid and Oldroyd-B fluid is revealed to be the fact that neutral mode exists only in the former.

  4. Theoretical Criteria for the Occurrence of Turbulence in Burger's Equation

    CERN Document Server

    Imperio, J C; Laganapan, A; Esguerra, J P H; Muriel, A

    2007-01-01

    Throughout the history of the study of turbulence in fluid dynamics, there has yet to arise a unique definition or theoretical criterion for this important phenomenon. There have been interesting conjectures made by Ruelle [2], Muriel [3], and Getreuer, Albano and Muriel [6], however, attempting to provide the sufficient criteria for the onset of turbulence. In this paper, a classic equation in fluid dynamics, Burger's equation, is solved in one and two dimensions, and these conjectures are illustrated. This illustration supports these conjectures by showing that the proposed criteria do arise mathematically from the solutions of an equation modelling fluid flows.

  5. Operator splitting for partial differential equations with Burgers nonlinearity

    CERN Document Server

    Holden, Helge; Risebro, Nils Henrik

    2011-01-01

    We provide a new analytical approach to operator splitting for equations of the type $u_t=Au+u u_x$ where $A$ is a linear differential operator such that the equation is well-posed. Particular examples include the viscous Burgers' equation, the Korteweg-de Vries (KdV) equation, the Benney-Lin equation, and the Kawahara equation. We show that the Strang splitting method converges with the expected rate if the initial data are sufficiently regular. In particular, for the KdV equation we obtain second-order convergence in $H^r$ for initial data in $H^{r+5}$ with arbitrary $r\\ge 1$.

  6. Approximate solutions of general perturbed KdV-Burgers equations

    Directory of Open Access Journals (Sweden)

    Baojian Hong

    2014-09-01

    Full Text Available In this article, we present some approximate analytical solutions to the general perturbed KdV-Burgers equation with nonlinear terms of any order by applying the homotopy analysis method (HAM. While compared with the Adomain decomposition method (ADM and the homotopy perturbation method (HPM, the HAM contains the auxiliary convergence-control parameter $\\hbar$ and the control function $H(x,t$, which provides a useful way to adjust and control the convergence region of solution series. The numerical results reveal that HAM is accurate and effective when it is applied to the perturbed PDEs.

  7. Moyal noncommutative integrability and the Burgers-KdV mapping

    Energy Technology Data Exchange (ETDEWEB)

    Sedra, M.B. [International Centre for Theoretical Physics, Trieste (Italy) and Virtual African Center for Basic Sciences and Technology, VACBT, Focal point: Lab/UFR-Physique des Haute Energies, Faculte des Sciences, Rabat (Morocco) and Groupement National de Physique de Hautes Energies, GNPHE, Rabat (Morocco) and Universite Ibn Tofail, Faculte des Sciences, Departement de Physique, Laboratoire de Physique de la Matiere et Rayonnement - LPMR, Kenitra (Morocco)]. E-mail: sedra@ictp.it

    2006-04-24

    The Moyal momentum algebra, studied in previous occasions, is once again used to discuss some important aspects of NC integrable models and 2d conformal field theories. Among the results presented, we setup algebraic structures and makes useful convention notations leading to extract nontrivial properties of the Moyal momentum algebra. We study also the Lax pair building mechanism for particular examples namely, the noncommutative KdV and Burgers systems. We show in a crucial step that these two systems are mapped to each others through the following crucial mapping -bar {sub t2}-bar -bar {sub t3}=-bar {sub t2}-bar {sub x}+{alpha}-bar {sub x}{sup 3}. This makes a strong constraint on the NC Burgers system which corresponds to linearizing its associated differential equation. From the CFT's point of view, this constraint equation is nothing but the analogue of the conservation law of the conformal current. We believe that the considered mapping might help to bring new insights towards understanding the integrability of noncommutative 2d-systems.

  8. Burgers方程的精确解%Exact solutions of Burgers equations

    Institute of Scientific and Technical Information of China (English)

    李伟

    2013-01-01

    借助于Cole-Hope变换,积分变换法和拟解的方法,获得Burgers方程,(2+1)维Burgers方程,(2+1)维高阶Burgers方程的新的精确解.这种方法可以解决一系列的偏微分方程.%With the help of cole - Hope transform, integral method and quasi solution method, some new exact solutions of Burgers equation, (2 +1) dimensional Burger equation and ( 2 + 1) dimensional higher - order Burgers equation were presented. This method could solve a series of partial differential equations.

  9. Kolmogorov turbulence in a random-force-driven Burgers equation

    CERN Document Server

    Chekhlov, A; Chekhlov, Alexei; Yakhot, Victor

    1995-01-01

    The dynamics of velocity fluctuations, governed by the one-dimensional Burgers equation, driven by a white-in-time random force with the spatial spectrum \\overline{|f(k)|^2}\\proptok^{-1}, is considered. High-resolution numerical experiments conducted in this work give the energy spectrum E(k)\\propto k^{-\\beta} with \\beta =5/3\\pm 0.02. The observed two-point correlation function C(k,\\omega) reveals \\omega\\propto k^z with the "dynamical exponent" z\\approx 2/3. High-order moments of velocity differences show strong intermittency and are dominated by powerful large-scale shocks. The results are compared with predictions of the one-loop renormalized perturbation expansion.

  10. Subensemble decomposition and Markov process analysis of Burgers turbulence.

    Science.gov (United States)

    Zhang, Zhi-Xiong; She, Zhen-Su

    2011-08-01

    A numerical and statistical study is performed to describe the positive and negative local subgrid energy fluxes in the one-dimensional random-force-driven Burgers turbulence (Burgulence). We use a subensemble method to decompose the field into shock wave and rarefaction wave subensembles by group velocity difference. We observe that the shock wave subensemble shows a strong intermittency which dominates the whole Burgulence field, while the rarefaction wave subensemble satisfies the Kolmogorov 1941 (K41) scaling law. We calculate the two subensemble probabilities and find that in the inertial range they maintain scale invariance, which is the important feature of turbulence self-similarity. We reveal that the interconversion of shock and rarefaction waves during the equation's evolution displays in accordance with a Markov process, which has a stationary transition probability matrix with the elements satisfying universal functions and, when the time interval is much greater than the corresponding characteristic value, exhibits the scale-invariant property.

  11. Linear stability of plane creeping Couette flow for Burgers fluid

    Institute of Scientific and Technical Information of China (English)

    Kai-Xin Hu; Jie Peng; Ke-Qin Zhu

    2013-01-01

    It is well known that plane creeping Couette flow of UCM and Oldroy-B fluids are linearly stable.However,for Burges fluid,which includes UCM and Oldroyd-B fluids as special cases,unstable modes are detected in the present work.The wave speed,critical parameters and perturbation mode are studied for neutral waves.Energy analysis shows that the sustaining of perturbation energy in Poiseuille flow and Couette flow is completely different.At low Reynolds number limit,analytical solutions are obtained for simplified perturbation equations.The essential difference between Burgers fluid and Oldroyd-B fluid is revealed to be the fact that neutral mode exists only in the former.

  12. Evaluation of explicit and implicit LES closures for Burgers turbulence

    CERN Document Server

    Maulik, Romit

    2016-01-01

    In this work, we perform an aposteriori error analysis on implicit and explicit large eddy simulation closure models for solving the Burgers turbulence problem. Our closure modeling efforts include both functional and structural models equipped with various low-pass filters. We introduce discrete binomial smoothing filters and an enhanced version of the Van Cittert algorithm to accelerate the convergence of approximate deconvolution processes including regularization and relaxation filtering approaches. Our implicit modeling efforts consist of various high-order schemes including compact and non-compact fifth-order upwind schemes as well as weighted essential non-oscillatory (WENO) and compact reconstructed WENO (CRWENO) schemes, and the resulting schemes are shown to effectively converge to the direct numerical simulation (DNS) for increasing resolutions. Comparing with DNS and underresolved DNS computations, our numerical assessments illustrate the ability of these methods to capture the energy content near...

  13. Self-adjointness and conservation laws of a generalized Burgers equation

    Energy Technology Data Exchange (ETDEWEB)

    Ibragimov, N H [Department of Mathematics and Science, Blekinge Institute of Technology, SE-371 79 Karlskrona (Sweden); Torrisi, M; Tracina, R, E-mail: nib@bth.se, E-mail: torrisi@dmi.unict.it, E-mail: tracina@dmi.unict.it [Dipartimento di Matematica e Informatica, University of Catania, Catania (Italy)

    2011-04-08

    A (2 + 1)-dimensional generalized Burgers equation is considered. Having written this equation as a system of two dependent variables, we show that it is quasi self-adjoint and find a nontrivial additional conservation law.

  14. EXISTENCE OF PERIODIC SOLUTIONS OF THE BURGERS-GINZBURG-LANDAU EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    黄海洋

    2004-01-01

    In this paper, the existence of the periodic solutions for a forced Burgers equation coupled to a non-homogeneous Ginzburg-Landau equation is proved by LeraySchauder fixed point theorem and Galerkin method under appropriate conditions.

  15. A unified approach to an augmented Burgers equation for the propagation of sonic booms.

    Science.gov (United States)

    Yamamoto, Masafumi; Hashimoto, Atsushi; Aoyama, Takashi; Sakai, Takeharu

    2015-04-01

    Nonlinear propagation through a relaxing atmosphere of pressure disturbances extracted from a computational fluid dynamics (CFD) solution of the flow around a supersonic aircraft is simulated using an augmented Burgers equation. The effects of nonlinearity, geometrical spreading, atmospheric inhomogeneity, thermoviscous attenuation, and molecular vibration relaxation are taken into account. The augmented Burgers equation used for sonic boom propagation calculations is often solved by the operator splitting method, but numerical difficulties arise with this approach when dissipation is not effective. By re-examining the solution algorithms for the augmented Burgers equation, a stable method for handling the relaxation effect has been developed. This approach can handle the Burgers equation in a unified manner without operator splitting and, therefore, the resulting scheme is twice as fast as the original one. The approach is validated by comparing it with an analytical solution and a detailed CFD of dispersed plane wave propagation. In addition, a rise time prediction of low-boom supersonic aircraft is demonstrated.

  16. Multi-soliton solution, rational solution of the Boussinesq-Burgers equations

    Science.gov (United States)

    Abdel Rady, A. S.; Osman, E. S.; Khalfallah, Mohammed

    2010-05-01

    In this paper we consider the Boussinesq-Burgers equations and establish the transformation which turns the Boussinesq-Burgers equations into the single nonlinear partial differential equation, then we obtain an auto-Bäcklund transformation and abundant new exact solutions, including the multi-solitary wave solution and the rational series solutions. Besides the new trigonometric function periodic solutions are obtained by using the generalized tan h method.

  17. Laplace homotopy perturbation method for Burgers equation with space- and time-fractional order

    Science.gov (United States)

    Johnston, S. J.; Jafari, H.; Moshokoa, S. P.; Ariyan, V. M.; Baleanu, D.

    2016-07-01

    The fractional Burgers equation describes the physical processes of unidirectional propagation of weakly nonlinear acoustic waves through a gas-filled pipe. The Laplace homotopy perturbation method is discussed to obtain the approximate analytical solution of space-fractional and time-fractional Burgers equations. The method used combines the Laplace transform and the homotopy perturbation method. Numerical results show that the approach is easy to implement and accurate when applied to partial differential equations of fractional orders.

  18. Laplace homotopy perturbation method for Burgers equation with space- and time-fractional order

    Directory of Open Access Journals (Sweden)

    Johnston S. J.

    2016-01-01

    Full Text Available The fractional Burgers equation describes the physical processes of unidirectional propagation of weakly nonlinear acoustic waves through a gas-filled pipe. The Laplace homotopy perturbation method is discussed to obtain the approximate analytical solution of space-fractional and time-fractional Burgers equations. The method used combines the Laplace transform and the homotopy perturbation method. Numerical results show that the approach is easy to implement and accurate when applied to partial differential equations of fractional orders.

  19. Analytical Approach to Space-and Time-Fractional Burgers Equations

    Institute of Scientific and Technical Information of China (English)

    Ahmet Yildirim; Syed Tauseef Mohyud-Din

    2010-01-01

    @@ A scheme is developed to study numerical solution of the space- and time-fractional Burgers equations under initial conditions by the homotopy analysis method.The fractional derivatives axe considered in the Caputo sense.The solutions are given in the form of series with easily computable terms.Numerical solutions are calculated for the fractional Burgers equation to show the nature of solution as the fractional derivative parameter is changed.

  20. NEW EXPLICIT AND EXACT TRAVELLING WAVE SOLUTIONS FOR A COMPOUND KdV-BURGERS EQUATION

    Institute of Scientific and Technical Information of China (English)

    XIA TIE-CHENG; ZHANG HONG-QING; YAN ZHEN-YA

    2001-01-01

    In this paper, new explicit and exact travelling wave solutions for a compound KdV-Burgers equation are obtained by using the hyperbola function method and the Wu elimination method, which include new solitary wave solutions and periodic solutions. Particularly important cases of the equation, such as the compound KdV, mKdV-Burgers and mKdV equations can be solved by this method. The method can also solve other nonlinear partial differential equations.

  1. PAINLEV PROPERTY OF BURGERS-KDV EQUATION AND ITS EXACT SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper, we introduce the Painlev property of the Burgers-KdV equation. Two types of exact solutions to the equation are obtained by the standard truncated expansion metIn this paper, we introduce the Painlev property of the Burgers-KdV equation. Two types of exact solutions to the equation are obtained by the standard truncated expansion method and the extended standard truncated expansion method, respectively.hod and the extended standard truncated expansion method, respectively.

  2. A Lattice Boltzmann Model and Simulation of KdV-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    ZHANGChao-Ying; TANHui-Li; LIUMu-Ren; KONGLing-Jiang

    2004-01-01

    A lattice Boltzmann model of KdV-Burgers equation is derived by using the single-relaxation form of the lattice Boltzmann equation. With the present model, we simulate the traveling-wave solutions, the solitary-wave solutions, and the sock-wave solutions of KdV-Burgers equation, and calculate the decay factor and the wavelength of the sock-wave solution, which has exponential decay. The numerical results agree with the analytical solutions quite well.

  3. A New Lattice Boltzmann Model for KdV-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    MA Chang-Feng

    2005-01-01

    @@ A new lattice Boltzmann model with amending-function for KdV-Burgers equation, ut +uux - αuxx +βuxxx = 0,is presented by using the single-relaxation form of the lattice Boltzmann equation. Applying the proposed model,we simulate the solutions ofa kind of KdV-Burgers equations, and the numerical results agree with the analytical solutions quite well.

  4. Traveling wave solution of fractional KdV-Burger-Kuramoto equation describing nonlinear physical phenomena

    Science.gov (United States)

    Gupta, A. K.; Ray, S. Saha

    2014-09-01

    In this paper, KdV-Burger-Kuramoto equation involving instability, dissipation, and dispersion parameters is solved numerically. The numerical solution for the fractional order KdV-Burger-Kuramoto (KBK) equation has been presented using two-dimensional Legendre wavelet method. The approximate solutions of nonlinear fractional KBK equation thus obtained by Legendre wavelet method are compared with the exact solutions. The present scheme is very simple, effective and convenient for obtaining numerical solution of the KBK equation.

  5. Traveling wave solution of fractional KdV-Burger-Kuramoto equation describing nonlinear physical phenomena

    Directory of Open Access Journals (Sweden)

    A. K. Gupta

    2014-09-01

    Full Text Available In this paper, KdV-Burger-Kuramoto equation involving instability, dissipation, and dispersion parameters is solved numerically. The numerical solution for the fractional order KdV-Burger-Kuramoto (KBK equation has been presented using two-dimensional Legendre wavelet method. The approximate solutions of nonlinear fractional KBK equation thus obtained by Legendre wavelet method are compared with the exact solutions. The present scheme is very simple, effective and convenient for obtaining numerical solution of the KBK equation.

  6. The Exact Analytical Solutions to the Burgers-KdV Equation by the Superposition Approach%用叠加法求Burgers-KdV方程的精确解析解

    Institute of Scientific and Technical Information of China (English)

    刘辉; 谢元喜

    2005-01-01

    基于对Burgers方程、KdV方程和Burgers-KdV方程特点的分析,提出了一种由Burgers方程的解和KdV方程的解构造Burgers-KdV方程的解的叠加法,并用该法求得了Burgers-KdV方程的解,所得结果与已有结果完全吻合.

  7. The inviscid, compressible and rotational, 2D isotropic Burgers and pressureless Euler-Coriolis fluids: Solvable models with illustrations

    Science.gov (United States)

    Choquard, Ph.; Vuffray, M.

    2014-10-01

    The coupling between dilatation and vorticity, two coexisting and fundamental processes in fluid dynamics (Wu et al., 2006, pp. 3, 6) is investigated here, in the simplest cases of inviscid 2D isotropic Burgers and pressureless Euler-Coriolis fluids respectively modeled by single vortices confined in compressible, local, inertial and global, rotating, environments. The field equations are established, inductively, starting from the equations of the characteristics solved with an initial Helmholtz decomposition of the velocity fields namely a vorticity free and a divergence free part (Wu et al., 2006, Sects. 2.3.2, 2.3.3) and, deductively, by means of a canonical Hamiltonian Clebsch like formalism (Clebsch, 1857, 1859), implying two pairs of conjugate variables. Two vector valued fields are constants of the motion: the velocity field in the Burgers case and the momentum field per unit mass in the Euler-Coriolis one. Taking advantage of this property, a class of solutions for the mass densities of the fluids is given by the Jacobian of their sum with respect to the actual coordinates. Implementation of the isotropy hypothesis entails a radial dependence of the velocity potentials and of the stream functions associated to the compressible and to the rotational part of the fluids and results in the cancellation of the dilatation-rotational cross terms in the Jacobian. A simple expression is obtained for all the radially symmetric Jacobians occurring in the theory. Representative examples of regular and singular solutions are shown and the competition between dilatation and vorticity is illustrated. Inspired by thermodynamical, mean field theoretical analogies, a genuine variational formula is proposed which yields unique measure solutions for the radially symmetric fluid densities investigated. We stress that this variational formula, unlike the Hopf-Lax formula, enables us to treat systems which are both compressible and rotational. Moreover in the one

  8. A Collocation Method for Numerical Solutions of Coupled Burgers' Equations

    Science.gov (United States)

    Mittal, R. C.; Tripathi, A.

    2014-09-01

    In this paper, we propose a collocation-based numerical scheme to obtain approximate solutions of coupled Burgers' equations. The scheme employs collocation of modified cubic B-spline functions. We have used modified cubic B-spline functions for unknown dependent variables u, v, and their derivatives w.r.t. space variable x. Collocation forms of the partial differential equations result in systems of first-order ordinary differential equations (ODEs). In this scheme, we did not use any transformation or linearization method to handle nonlinearity. The obtained system of ODEs has been solved by strong stability preserving the Runge-Kutta method. The proposed scheme needs less storage space and execution time. The test problems considered in the literature have been discussed to demonstrate the strength and utility of the proposed scheme. The computed numerical solutions are in good agreement with the exact solutions and competent with those available in earlier studies. The scheme is simple as well as easy to implement. The scheme provides approximate solutions not only at the grid points, but also at any point in the solution range.

  9. Generalized Magnetic Field Effects in Burgers' Nanofluid Model

    Science.gov (United States)

    Rashidi, M. M.; Yang, Z.; Awais, Muhammad; Nawaz, Maria; Hayat, Tasawar

    2017-01-01

    Analysis has been conducted to present the generalized magnetic field effects on the flow of a Burgers' nanofluid over an inclined wall. Mathematical modelling for hydro-magnetics reveals that the term “σB02u/ρ” is for the Newtonian model whereas the generalized magnetic field term (as mentioned in Eq 4) is for the Burgers’ model which is incorporated in the current analysis to get the real insight of the problem for hydro-magnetics. Brownian motion and thermophoresis phenomenon are presented to analyze the nanofluidics for the non-Newtonian fluid. Mathematical analysis is completed in the presence of non-uniform heat generation/absorption. The constructed set of partial differential system is converted into coupled nonlinear ordinary differential system by employing the suitable transformations. Homotopy approach is employed to construct the analytical solutions which are shown graphically for sundr5y parameters including Deborah numbers, magnetic field, thermophoresis, Brownian motion and non-uniform heat generation/absorption. A comparative study is also presented showing the comparison of present results with an already published data. PMID:28045965

  10. Non-linear vorticity upsurge in Burgers flow

    CERN Document Server

    Lam, F

    2016-01-01

    We demonstrate that numerical solutions of Burgers' equation can be obtained by a scale-totality algorithm for fluids of small viscosity (down to one billionth). Two sets of initial data, modelling simple shears and wall boundary layers, are chosen for our computations. Most of the solutions are carried out well into the fully turbulent regime over finely-resolved scales in space and in time. It is found that an abrupt spatio-temporal concentration in shear constitutes an essential part during the flow evolution. The vorticity surge has been instigated by the non-linearity complying with instantaneous enstrophy production while ad hoc disturbances play no role in the process. In particular, the present method predicts the precipitous vorticity re-distribution and accumulation, predominantly over localised regions of minute dimension. The growth rate depends on viscosity and is a strong function of initial data. Nevertheless, the long-time energy decay is history-independent and is inversely proportional to ti...

  11. Generalized Burgers equations and Euler-Painlevé transcendents. III

    Science.gov (United States)

    Sachdev, P. L.; Nair, K. R. C.; Tikekar, V. G.

    1988-11-01

    It was proposed earlier [P. L. Sachdev, K. R. C. Nair, and V. G. Tikekar, J. Math. Phys. 27, 1506 (1986); P. L. Sachdev and K. R. C. Nair, ibid. 28, 977 (1987)] that the Euler-Painlevé equations y(d2y/dη2)+a(dy/dη)2 +f(η)y(dy/dη)+g(η)y2+b(dy/dη) +c=0 represent generalized Burgers equations (GBE's) in the same way as Painlevé equations represent the Korteweg-de Vries type of equations. The earlier studies were carried out in the context of GBE's with damping and those with spherical and cylindrical symmetry. In the present paper, GBE's with variable coefficients of viscosity and those with inhomogeneous terms are considered for their possible connection to Euler-Painlevé equations. It is found that the Euler-Painlevé equation, which represents the GBE ut+uβux=(δ/2)g(t)uxx, g(t)=(1+t)n, β>0, has solutions, which either decay or oscillate at η=±∞, only when -1Kamke [Differential Gleichungen : Lösungsmethoden und Lösungen (Akademische Verlagsgesellschaft, Leipzig, 1943)] and Murphy [Ordinary Differential Equations and their Solutions (Van Nostrand, Princeton, NJ, 1960)]. These latter equations arise from a wide range of physical applications and are of some historical interest as well. They are all special cases of a slightly generalized form of the Euler-Painlevé equation.

  12. Generalized Burgers equations and Euler-Painlevé transcendents. I

    Science.gov (United States)

    Sachdev, P. L.; Nair, K. R. C.; Tikekar, V. G.

    1986-06-01

    Initial-value problems for the generalized Burgers equation (GBE) ut+u βux+λuα =(δ/2)uxx are discussed for the single hump type of initial data—both continuous and discontinuous. The numerical solution is carried to the self-similar ``intermediate asymptotic'' regime when the solution is given analytically by the self-similar form. The nonlinear (transformed) ordinary differential equations (ODE's) describing the self-similar form are generalizations of a class discussed by Euler and Painlevé and quoted by Kamke. These ODE's are new, and it is postulated that they characterize GBE's in the same manner as the Painlevé equations categorize the Kortweg-de Vries (KdV) type. A connection problem for some related ODE's satisfying proper asymptotic conditions at x=±∞, is solved. The range of amplitude parameter is found for which the solution of the connection problem exists. The other solutions of the above GBE, which display several interesting features such as peaking, breaking, and a long shelf on the left for negative values of the damping coefficient λ, are also discussed. The results are compared with those holding for the modified KdV equation with damping.

  13. Introducing Vectors.

    Science.gov (United States)

    Roche, John

    1997-01-01

    Suggests an approach to teaching vectors that promotes active learning through challenging questions addressed to the class, as opposed to subtle explanations. Promotes introducing vector graphics with concrete examples, beginning with an explanation of the displacement vector. Also discusses artificial vectors, vector algebra, and unit vectors.…

  14. On "new travelling wave solutions" of the KdV and the KdV-Burgers equations

    NARCIS (Netherlands)

    Kudryashov, Nikolai A.

    2009-01-01

    The Korteweg-de Vries and the Korteweg-de Vries-Burgers equations are considered. Using the travelling wave the general solutions of these equations are presented. "New travelling wave solutions" of the KdV and the KdV-Burgers equations by Wazzan [Wazzan L Commun Nonlinear Sci Numer Simulat 2009:14:

  15. New Travelling Wave Solutions of Burgers Equation with Finite Transport Memory

    Science.gov (United States)

    Sakthivel, Rathinasamy; Chun, Changbum; Lee, Jonu

    2010-09-01

    The nonlinear evolution equations with finite memory have a wide range of applications in science and engineering. The Burgers equation with finite memory transport (time-delayed) describes convection-diffusion processes. In this paper, we establish the new solitary wave solutions for the time-delayed Burgers equation. The extended tanh method and the exp-function method have been employed to reveal these new solutions. Further, we have calculated the numerical solutions of the time-delayed Burgers equation with initial conditions by using the homotopy perturbation method (HPM). Our results show that the extended tanh and exp-function methods are very effective in finding exact solutions of the considered problem and HPM is very powerful in finding numerical solutions with good accuracy for nonlinear partial differential equations without any need of transformation or perturbation

  16. Existence and uniqueness of entropy solution to initial boundary value problem for the inviscid Burgers equation

    CERN Document Server

    Zhu, C

    2003-01-01

    This paper is concerned with the existence and uniqueness of the entropy solution to the initial boundary value problem for the inviscid Burgers equation. To apply the method of vanishing viscosity to study the existence of the entropy solution, we first introduce the initial boundary value problem for the viscous Burgers equation, and as in Evans (1998 Partial Differential Equations (Providence, RI: American Mathematical Society) and Hopf (1950 Commun. Pure Appl. Math. 3 201-30), give the formula of the corresponding viscosity solutions by Hopf-Cole transformation. Secondly, we prove the convergence of the viscosity solution sequences and verify that the limiting function is an entropy solution. Finally, we give an example to show how our main result can be applied to solve the initial boundary value problem for the Burgers equation.

  17. Supersymmetric Representations and Integrable Fermionic Extensions of the Burgers and Boussinesq Equations

    Directory of Open Access Journals (Sweden)

    Arthemy V. Kiselev

    2006-02-01

    Full Text Available We construct new integrable coupled systems of N = 1 supersymmetric equations and present integrable fermionic extensions of the Burgers and Boussinesq equations. Existence of infinitely many higher symmetries is demonstrated by the presence of recursion operators. Various algebraic methods are applied to the analysis of symmetries, conservation laws, recursion operators, and Hamiltonian structures. A fermionic extension of the Burgers equation is related with the Burgers flows on associative algebras. A Gardner's deformation is found for the bosonic super-field dispersionless Boussinesq equation, and unusual properties of a recursion operator for its Hamiltonian symmetries are described. Also, we construct a three-parametric supersymmetric system that incorporates the Boussinesq equation with dispersion and dissipation but never retracts to it for any values of the parameters.

  18. Detailed evaluation of a newly attained fungal pigment from Monascus purpureus in meat burgers.

    Science.gov (United States)

    El-Kholie, Emad M; El Shaer, Magda K; Abdelreheem, Mohammed A T; Gharib, Mai A

    2012-11-01

    Beef burgers with red pigment extracted from Monascus purpureus, used as a natural colouring agent, were examined for chemical compositions, physical properties, microbiological aspects and organoleptic evaluation. Beef burgers with Monascus pigment showed higher nutritional values compared with control samples. Nutritional values were proportionally enhanced by increasing pigment concentration. Synthetic dye samples had the lowest values of nutrients. Cooking loss percentage and water holding capacity were lower in all treatments compared with control samples, and vice versa for plasticity. The initial total bacterial count, Staphylococcus aureus count and coliform count were determined. Extending storage period up to 90 days severely reduced all tested microorganisms. By increasing the M. pigment concentration, the colour was significantly increased. Insignificant differences in colours were noticed among various treatments. Flavour and body and texture scores were insignificantly different. Microbial inhibition percentage of beef burger samples was increased by increasing the Monascus pigment concentration up to 0.8 g/kg.

  19. Existence and uniqueness of entropy solution to initial boundary value problem for the inviscid Burgers equation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Changjiang; Duan, Renjun [Laboratory of Nonlinear Analysis, Department of Mathematics, Central China Normal University, Wuhan 430079, People' s Republic of China (China)

    2003-02-28

    This paper is concerned with the existence and uniqueness of the entropy solution to the initial boundary value problem for the inviscid Burgers equation. To apply the method of vanishing viscosity to study the existence of the entropy solution, we first introduce the initial boundary value problem for the viscous Burgers equation, and as in Evans (1998 Partial Differential Equations (Providence, RI: American Mathematical Society) and Hopf (1950 Commun. Pure Appl. Math. 3 201-30), give the formula of the corresponding viscosity solutions by Hopf-Cole transformation. Secondly, we prove the convergence of the viscosity solution sequences and verify that the limiting function is an entropy solution. Finally, we give an example to show how our main result can be applied to solve the initial boundary value problem for the Burgers equation.

  20. On the MHD flow of fractional generalized Burgers' fluid with modified Darcy's law

    Institute of Scientific and Technical Information of China (English)

    T. Hayat; M. Khan; S. Asghar

    2007-01-01

    This work is concerned with applying the fractional calculus approach to the magnetohydrodynamic(MHD) pipe flow of a fractional generalized Burgers' fluid in a porous space by using modified Darcy's relationship. The fluid is electrically conducting in the presence of a constant applied magnetic field in the transverse direction. Exact solution for the velocity distribution is developed with the help of Fourier transform for fractional calculus. The solutions for a Navier-Stokes, second grade, Maxwell, Oldroyd-B and Burgers' fluids appear as the limiting cases of the present analysis.

  1. Propagation of quasiplane nonlinear waves in tubes and the approximate solutions of the generalized Burgers equation.

    Science.gov (United States)

    Bednarik, Michal; Konicek, Petr

    2002-07-01

    This paper deals with using the generalized Burgers equation for description of nonlinear waves in circular ducts. Two new approximate solutions of the generalized Burgers equation (GBE) are presented. These solutions take into account the boundary layer effects. The first solution is valid for the preshock region and gives more precise results than the Fubini solution, whereas the second one is valid for the postshock (sawtooth) region and provides better results than the Fay solution. The approximate solutions are compared with numerical results of the GBE. Furthermore, the limits of validity of the used model equation are discussed with respect to boundary conditions and radius of a circular duct.

  2. Singular sector of the Burgers-Hopf hierarchy and deformations of hyperelliptic curves

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Yuji [Department of Mathematics, Ohio State University, Columbus, OH (United States)]. E-mail: kodama@math.ohio-state.edu; Konopelchenko, Boris G. [Dipartimento di Fisica, Universita di Lecce and Sezione INFN, Lecce (Italy)]. E-mail: konopel@le.infn.it

    2002-08-09

    We discuss the structure of shock singularities of the Burgers-Hopf hierarchy. It is shown that the set of singular solutions defines a stratification of the affine space of the flow parameters in the hierarchy. The stratification is associated with the Birkhoff decomposition of the Grassmannian given by the set of linear spaces spanned by the hierarchy. We then construct integrable hierarchy on each stratum and demonstrate that it describes a deformation of a hyperelliptic curve parametrizing the stratum. The hierarchy is called the hidden Burgers-Hopf hierarchy, and we found the Riemann invariant form and the hodograph solution. (author)

  3. New traveling-wave solution of nonlinear Kdv-Burgers-Kuramoto equation%非线性KdV-Burgers-Kuramoto方程新的行波解

    Institute of Scientific and Technical Information of China (English)

    毛杰健; 杨建荣

    2006-01-01

    用双曲正切函数n∑i=-ntanhi(ζ)展开法,得到了非线性KdV-Burgers-Kuramoto方程:ut+uux+αuxx+βuxxx+γuxxxx=0的36组行波解.KdV方程、KdV-Burgers方程和KS-KdV方程等的孤波解和行波解可作为特例类推得到.

  4. A Collocation Method for Numerical Solution of the Generalized Burgers-Huxley Equation

    Directory of Open Access Journals (Sweden)

    Mohammad ZAREBNIA

    2014-08-01

    Full Text Available In this paper, we use a collocation method to solve the Burgers-Huxley equation. To achieve this aim, we use mesh free technique based on sinc functions. The stability analysis is discussed. Some numerical examples are provided to illustrate the accuracy and fluency of the method.

  5. Combined effect of MAP and active compounds on fresh blue fish burger.

    Science.gov (United States)

    Del Nobile, M A; Corbo, M R; Speranza, B; Sinigaglia, M; Conte, A; Caroprese, M

    2009-11-15

    The combined effects of three essential oils [thymol, lemon extract and grapefruit seed extract (GFSE)] and modified atmosphere packaging conditions (MAP) on quality retention of blue fish burgers was studied and discussed. In particular, samples were packaged in air and in three different gas mix compositions: 30:40:30 O(2):CO(2):N(2), 50:50 O(2):CO(2) and 5:95 O(2):CO(2). During a 28-day storage period at 4 degrees C, the nutritional, microbiological and sensorial quality of the packed products was assessed. The potential development of biogenic amines was also evaluated. The obtained results highlight the possibility to improve the microbial quality of blue fish burgers by using very small amount of thymol (110ppm), GFSE (100ppm) and lemon extract (120ppm) in combination with MAP. Based primarily on microbiological results, the combined use of the tested natural preservatives and a packaging system characterized by a high CO(2)-concentration, was able to guarantee the microbial acceptability of fish burgers until the 28th day of storage at 4 degrees C. On the other hand, results from sensory analyses showed that sensorial quality was the sub-index that limited the burgers shelf life (to about 22-23days), even if the proposed strategy was also effective in minimizing the sensory quality loss of the product having no effect on its nutritional quality.

  6. New Exact Solutions and Localized Structures for (3+1)-Dimensional Burgers System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Shang; LI Jiang-Bo; MA Song-Hua; REN Qing-Bao; FANG Jian-Ping; ZHENG Chun-Long

    2008-01-01

    With an extended mapping approach and a linear variable separation method, new families of variable separation solutions (including solitary wave solutions, periodic wave solutions, and rational function solutions) with arbitrary functions for (3+1)-dimensional Burgers system is derived. Based on the derived excitations, we obtain some novel localized coherent structures and study the interactions between solitons.

  7. Nonlocalization of Nonlocal Symmetry and Symmetry Reductions of the Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    金艳; 贾曼; 楼森岳

    2012-01-01

    Symmetry reduction method is one of the best ways to find exact solutions. In this paper, we study the possibility of symmetry reductions of the well known Burgers equation including the nonlocal symmetry. The related new group Jnvariant solutions are obtained. Especially, the interactions among solitons, Airy waves, and Kummer waves are explicitly given.

  8. The solution of Burgers' and good Boussinesq equations using ADM-Pade technique

    Energy Technology Data Exchange (ETDEWEB)

    Abassy, Tamer A. [Department of Basic Science, Benha Higher Institute of Technology, Benha, 13512 (Egypt)]. E-mail: tamerabassy@yahoo.com; El-Tawil, Magdy A. [Department of Engineering Mathematics and Physics, Faculty of Engineering, Cairo University, Giza (Egypt)]. E-mail: magdyeltawil@yahoo.com; Saleh, Hassan K. [Department of Engineering Mathematics and Physics, Faculty of Engineering, Cairo University, Giza (Egypt)

    2007-05-15

    ADM-Pade technique is a combination of Adomian decomposition method (ADM) and Pade approximants. It is an approximate method, which can be adapted to solve nonlinear partial differential equations. In this paper, we solve Burgers' and Boussinesq equation using ADM-Pade technique which gives the approximate solution with faster convergence rate and higher accuracy than using ADM alone.

  9. A Two-Component Generalization of Burgers' Equation with Quasi-Periodic Solution

    Science.gov (United States)

    Pan, Hongfei; Xia, Tiecheng; Chen, Dengyuan

    2014-10-01

    In this paper, we aim for the theta function representation of quasi-periodic solution and related crucial quantities for a two-component generalization of Burgers' equation. Our tools include the theory of algebraic curves, meromorphic functions, Baker-Akhiezer functions and the Dubrovin-type equations for auxiliary divisor. Eith these tools, the explicit representations for above quantities are obtained.

  10. New iterative method for fractional gas dynamics and coupled Burger's equations.

    Science.gov (United States)

    Al-Luhaibi, Mohamed S

    2015-01-01

    This paper presents the approximate analytical solutions to solve the nonlinear gas dynamics and coupled Burger's equations with fractional time derivative. By using initial values, the explicit solutions of the equations are solved by using a reliable algorithm. Numerical results show that the new iterative method is easy to implement and accurate when applied to time-fractional partial differential equations.

  11. A control problem for Burgers' equation with bounded input/output

    Science.gov (United States)

    Burns, John A.; Kang, Sungkwon

    1990-01-01

    A stabilization problem for Burgers' equation is considered. Using linearization, various controllers are constructed which minimize certain weighted energy functionals. These controllers produce the desired degree of stability for the closed-loop nonlinear system. A numerical scheme for computing the feedback gain functional is developed and several numerical experiments are performed to show the theoretical results.

  12. EXISTENCE OF WEAK SOLUTIONS FOR A DEGENERATE GENERALIZED BURGERS EQUATION WITH LARGE INITIAL DATA

    Institute of Scientific and Technical Information of China (English)

    张辉

    2002-01-01

    It is obtained the existence of the weak solution for a degenerate generalized Burgers equation under the restriction u0 ∈ L∞. The main method is to add viscosity perturbation and obtain some estimates in L1 norm. Meanwhile it is obtained the solution is exponential decay when the initial data has compact support.

  13. Large Time Behaviour of Solutions of a System of Generalized Burgers Equation

    Indian Academy of Sciences (India)

    K T Joseph

    2005-11-01

    In this paper we study the asymptotic behaviour of solutions of a system of partial differential equations. When = 1 the equation reduces to the Burgers equation and was studied by Hopf. We consider both the inviscid and viscous case and show a new feature in the asymptotic behaviour.

  14. Lie Group Classifications and Non-differentiable Solutions for Time-Fractional Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    WU Guo-Cheng

    2011-01-01

    Lie group method provides an efficient tool to solve nonlinear partial differential equations.This paper suggests Lie group method for fractional partial differential equations.A time-fractional Burgers equation is used as an example to illustrate the effectiveness of the Lie group method and some classes of exact solutions are obtained.

  15. New Multiple Soliton-like Solutions to (3+1)-Dimensional Burgers Equation with Variable Coefficients

    Institute of Scientific and Technical Information of China (English)

    CHEN Huai-Tang; ZHANG Hong-Qing

    2004-01-01

    A new generalized tanh function method is used for constructing exact travelling wave solutions of nonlinear partial differential equations in a unified way. The main idea of this method is to take full advantage of the Riccati equation, which has more new solutions. More new multiple soliton-like solutions are obtained for the (3+ 1 )-dimensional Burgers equation with variable coefficients.

  16. Measurement and assessment of aflatoxin B1 and its producing molds in Iranian sausages and burgers

    Directory of Open Access Journals (Sweden)

    Siavash Maktabi

    2016-09-01

    Full Text Available Abstract Introduction: Aflatoxin B1 (AFB1 is one of the most well-known hepatocarcinogens in humans. Contamination of raw materials, used in the production of sausages and burgers, with aflatoxin producing molds can lead to increased level of aflatoxin in the final products and can impose hazards to human health. Unfortunately, aflatoxin is resistant to heating and freezing processes, etc. and can remain in these products untile consumption. Methods: During a six-month period, 45 sausage and 53 burger samples from valid brands across the country were randomly purchased from the stores. The samples were analyzed for AFB1 by ELISA technique. Meanwhile, the number of molds was calculated and aflatoxin producing molds were identified by direct and slide culture methods. Results: The findings showed that 2 susage samples (4.9% and 3 burger samples (6.3% were contaminated with >1 ng/g aflatoxin. Moreover, 4 burger samples (8.9% contaminated with mold included aspergillus flavus, aspergillus niger, mucor, and penicillium while, none of the susage samples showed mold contamination. Conclusion: The Iranian meat products had a relative aflatoxin B1 contamination during the study period, but the contamination rate was low and in allowable range. Standard hygienic preparation and packaging of meat products molds is recommended to reduce fungal contamination, especially aflatoxin-producing molds.

  17. Variable Separation Solutions for the (2+1)-Dimensional Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    唐晓艳; 楼森岳

    2003-01-01

    Considering that the multi-linear variable separation approach has been proved to be very useful to solve many (2+1)-dimensional integrable systems, we obtain the variable separation solutions of the Burgers equation with arbitrary number of variable separated functions. The Y-shaped soliton fusion phenomenon is revealed.

  18. Stochastic heat and Burgers equations and their singularities II - Analytical Properties and Limiting Distributions

    CERN Document Server

    Davies, I M; Zhao, H

    2004-01-01

    We study the inviscid limit, $\\mu\\to 0$, of the stochastic viscous Burgers equation, for the velocity field $v^{\\mu}(x,t)$, $t>0$, $x\\in\\mathbb R^d$,\\frac{\\partial{v^{\\mu}}}{\\partial{t}} + (v^{\\mu}\\cdot\

  19. Application of homotopy analysis method to fractional KdV-Burgers-Kuramoto equation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Lina [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)]. E-mail: songlina1981@yahoo.com.cn; Zhang, Hongqing [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)

    2007-07-16

    In the Letter, homotopy analysis method that developed for integer-order differential equation is directly extended to derive explicit and numerical solutions of nonlinear fractional differential equation for the first time. The fractional derivatives are described in the Caputo sense. To our knowledge, the Letter represents the first available numerical solutions of the fractional KdV-Burgers-Kuramoto equation.

  20. Okara, a soymilk industry by-product, as a non-meat protein source in reduced fat beef burgers

    Directory of Open Access Journals (Sweden)

    Simone Ing Tie Su

    2013-02-01

    Full Text Available Okara is a by-product generated during the manufacture of soymilk and tofu. Wet okara was added to beef burgers at 0%, 20%, and 25%. The effects of okara on certain physicochemical, textural, and sensory properties of reduced fat beef burgers were investigated. The beef burgers formulated with okara (104.0-106.0 kcal/100 g had 60% less calories than commercial beef burgers (268.8 kcal/100 g. The texture profile analysis showed that the addition of wet okara led to a significant increase in hardness (p < 0.05 and a concomitant reduction in the values of chewiness, springiness, and cohesiveness. Lower sensory scores (p < 0.05 of flavour were observed in the beef burgers containing 25% wet okara. However, the sensory evaluation results showed that juiciness, appearance, tenderness, and overall acceptability of beef burgers formulated with okara did not differ statistically from that of the control (0% okara. Wet okara (20% can be used as a non-meat protein source in the production of reduced-fat beef burgers without changing their sensory quality.

  1. Forced ILW-Burgers Equation as a Model for Rossby Solitary Waves Generated by Topography in Finite Depth Fluids

    Directory of Open Access Journals (Sweden)

    Hongwei Yang

    2012-01-01

    Full Text Available The paper presents an investigation of the generation, evolution of Rossby solitary waves generated by topography in finite depth fluids. The forced ILW- (Intermediate Long Waves- Burgers equation as a model governing the amplitude of solitary waves is first derived and shown to reduce to the KdV- (Korteweg-de Vries- Burgers equation in shallow fluids and BO- (Benjamin-Ono- Burgers equation in deep fluids. By analysis and calculation, the perturbation solution and some conservation relations of the ILW-Burgers equation are obtained. Finally, with the help of pseudospectral method, the numerical solutions of the forced ILW-Burgers equation are given. The results demonstrate that the detuning parameter α holds important implications for the generation of the solitary waves. By comparing with the solitary waves governed by ILW-Burgers equation and BO-Burgers equation, we can conclude that the solitary waves generated by topography in finite depth fluids are different from that in deep fluids.

  2. Apply of trigonometric series in Burgers-KdV equation%三角级数在 Burgers-KdV 混合型方程中的应用

    Institute of Scientific and Technical Information of China (English)

    马敏艳; 吉飞宇; 鱼翔

    2012-01-01

      利用三角级数法将 Burgers-KdV 混合型方程转化为一组非线性代数方程,进而用待定系数法求解方程组,最后求出了 Burgers-KdV 混合型方程的精确解%  The Burgers-KdV equation is changed into nonlinear algebraic equations based on the trigonometric series, and it can be solved by the method of undetermined coefficients and the Maple software. As a result, the exact solution to the Burgers-KdV equation is successfully derived.

  3. About vectors

    CERN Document Server

    Hoffmann, Banesh

    1975-01-01

    From his unusual beginning in ""Defining a vector"" to his final comments on ""What then is a vector?"" author Banesh Hoffmann has written a book that is provocative and unconventional. In his emphasis on the unresolved issue of defining a vector, Hoffmann mixes pure and applied mathematics without using calculus. The result is a treatment that can serve as a supplement and corrective to textbooks, as well as collateral reading in all courses that deal with vectors. Major topics include vectors and the parallelogram law; algebraic notation and basic ideas; vector algebra; scalars and scalar p

  4. Vector analysis

    CERN Document Server

    Newell, Homer E

    2006-01-01

    When employed with skill and understanding, vector analysis can be a practical and powerful tool. This text develops the algebra and calculus of vectors in a manner useful to physicists and engineers. Numerous exercises (with answers) not only provide practice in manipulation but also help establish students' physical and geometric intuition in regard to vectors and vector concepts.Part I, the basic portion of the text, consists of a thorough treatment of vector algebra and the vector calculus. Part II presents the illustrative matter, demonstrating applications to kinematics, mechanics, and e

  5. Non-Lie Symmetry Group and New Exact Solutions for the Two-Dimensional KdV-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; TIAN Ying-Hui; CHEN Han-Lin

    2011-01-01

    @@ By using the modified Clarkson-Kruskal (CK) direct method, we obtain the non-Lie symmetry group of the two-dimensional KdV-Burgers equation.Under some constraint conditions, Lie point symmetry is also obtained.Through the symmetry group, some new exact solutions of the two-dimensional KdV-Burgers equation are found.%By using the modified Clarkson-Kruskal (CK) direct method, we obtain the non-Lie symmetry group of the two-dimensional KdV-Burgers equation. Under some constraint conditions, Lie point symmetry is also obtained.Through the symmetry group, some new exact solutions of the two-dimensional KdV-Burgers equation are found.

  6. Anti-periodic traveling wave solution to a forced two-dimensional generalized KdV-Burgers equation

    Institute of Scientific and Technical Information of China (English)

    TAN Junyu

    2003-01-01

    The anti-periodic traveling wave solutions to a forced two-dimensional generalized KdV-Burgers equation are studied.Some theorems concerning the boundness, existence and uniqueness of the solution to this equation are proved.

  7. Three Different Ways of Calibrating Burger's Contact Model for Viscoelastic Model of Asphalt Mixtures by Discrete Element Method

    DEFF Research Database (Denmark)

    Feng, Huan; Pettinari, Matteo; Stang, Henrik

    2016-01-01

    modulus. Three different approaches have been used and compared for calibrating the Burger's contact model. Values of the dynamic modulus and phase angle of asphalt mixtures were predicted by conducting DE simulation under dynamic strain control loading. The excellent agreement between the predicted......In this paper the viscoelastic behavior of asphalt mixture was investigated by employing a three-dimensional discrete element method. Combined with Burger's model, three contact models were used for the construction of constitutive asphalt mixture model with viscoelastic properties...... in the commercial software PFC3D, including the slip model, linear stiffness-contact model, and contact bond model. A macro-scale Burger's model was first established and the input parameters of Burger's contact model were calibrated by adjusting them so that the model fitted the experimental data for the complex...

  8. Exact Solutions of Generalized Boussinesq-Burgers Equations and (2+1-Dimensional Davey-Stewartson Equations

    Directory of Open Access Journals (Sweden)

    Isaiah Elvis Mhlanga

    2012-01-01

    Full Text Available We study two coupled systems of nonlinear partial differential equations, namely, generalized Boussinesq-Burgers equations and (2+1-dimensional Davey-Stewartson equations. The Lie symmetry method is utilized to obtain exact solutions of the generalized Boussinesq-Burgers equations. The travelling wave hypothesis approach is used to find exact solutions of the (2+1-dimensional Davey-Stewartson equations.

  9. STABILITY OF THE RAREFACTION WAVE FOR THE GENERALIZED KDV-BURGERS EQUATION

    Institute of Scientific and Technical Information of China (English)

    王治安; 朱长江

    2002-01-01

    This paper is concerned with the stability of the rarefaction wave for the generalized KdV-Burgers equation{ut + f(u)x = uuxx +δu tu > 0, 5 ∈ Ru|t=o = uo(x) → u+, x →±∞. (1)Roughly speaking, under the assumption that u- < u+, the solution u(x, t) to Cauchy problem (1) satisfying supx∈R |u(x't) - uR(x/t)| → 0 as t →∞, where uR(x/t) is the rarefaction wave of the non-viscous Burgers equation ut + f(u)x = 0 with Riemann initial dataut (x,0)={u-, x<0,u+, x>0.

  10. The tyger phenomenon for the Galerkin-truncated Burgers and Euler equations

    CERN Document Server

    Ray, Samriddhi Sankar; Nazarenko, Sergei; Matsumoto, Takeshi

    2010-01-01

    It is shown that the solutions of inviscid hydrodynamical equations with suppression of all spatial Fourier modes having wavenumbers in excess of a threshold $\\kg$ exhibit unexpected features. The study is carried out for both the one-dimensional Burgers equation and the two-dimensional incompressible Euler equation. At large $\\kg$, for smooth initial conditions, the first symptom of truncation, a localized short-wavelength oscillation which we call a "tyger", is caused by a resonant interaction between fluid particle motion and truncation waves generated by small-scale features (shocks, layers with strong vorticity gradients, etc). These tygers appear when complex-space singularities come within one Galerkin wavelength $\\lambdag = 2\\pi/\\kg$ from the real domain and typically arise far away from preexisting small-scale structures at locations whose velocities match that of such structures. Tygers are weak and strongly localized at first - in the Burgers case at the time of appearance of the first shock their ...

  11. New periodic wave solutions, localized excitations and their interaction for (2+1)-dimensional Burgers equation

    Institute of Scientific and Technical Information of China (English)

    Ma Hong-Cai; Ge Dong-Jie; Yu Yao-Dong

    2008-01-01

    Based on the B(a)cklund method and the multilinear variable separation approach (MLVSA), this paper finds a general solution including two arbitrary functions for the (2+1)-dimensional Burgers equations. Then a class of new doubly periodic wave solutions for (2+1)-dimensional Burgers equations is obtained by introducing appropriate Jacobi elliptic functions, Weierstrass elliptic functions and their combination in the general solutions (which contains two arbitrary functions). Two types of limit cases are considered. Firstly, taking one of the moduli to be unity and the other zero, it obtains particular wave (called semi-localized) patterns, which is periodic in one direction, but localized in the other direction. Secondly, if both moduli are tending to 1 as a limit, it derives some novel localized excitations (two-dromion solution).

  12. Optimal response to non-equilibrium disturbances under truncated Burgers-Hopf dynamics

    CERN Document Server

    Thalabard, Simon

    2016-01-01

    We model and compute the average response of truncated Burgers-Hopf dynamics to finite perturbations away from the Gibbs equipartition energy spectrum using a dynamical optimization framework recently conceptualized in a series of papers. Non-equilibrium averages are there approximated in terms of geodesic paths in probability space that best-fit the Liouvillean dynamics over a family of quasi-equilibrium trial densities. By recasting the geodesic principle as an optimal control problem, we solve numerically for the non-equilibrium responses using an augmented Lagrangian, non-linear conjugate gradient descent method. For moderate perturbations, we find an excellent agreement between the optimal predictions and the direct numerical simulations of the truncated Burgers-Hopf dynamics. In this near-equilibrium regime, we argue that the optimal response theory provides an approximate yet predictive counterpart to fluctuation-dissipation identities.

  13. Approximate analytical solution of the nonlinear fractional KdV-Burgers equation: A new iterative algorithm

    Science.gov (United States)

    El-Ajou, Ahmad; Arqub, Omar Abu; Momani, Shaher

    2015-07-01

    In this paper, explicit and approximate solutions of the nonlinear fractional KdV-Burgers equation with time-space-fractional derivatives are presented and discussed. The solutions of our equation are calculated in the form of rabidly convergent series with easily computable components. The utilized method is a numerical technique based on the generalized Taylor series formula which constructs an analytical solution in the form of a convergent series. Five illustrative applications are given to demonstrate the effectiveness and the leverage of the present method. Graphical results and series formulas are utilized and discussed quantitatively to illustrate the solution. The results reveal that the method is very effective and simple in determination of solution of the fractional KdV-Burgers equation.

  14. Elementary vectors

    CERN Document Server

    Wolstenholme, E Œ

    1978-01-01

    Elementary Vectors, Third Edition serves as an introductory course in vector analysis and is intended to present the theoretical and application aspects of vectors. The book covers topics that rigorously explain and provide definitions, principles, equations, and methods in vector analysis. Applications of vector methods to simple kinematical and dynamical problems; central forces and orbits; and solutions to geometrical problems are discussed as well. This edition of the text also provides an appendix, intended for students, which the author hopes to bridge the gap between theory and appl

  15. Combined equations of the Burgers hierarchy: multiple kink solutions and multiple singular kink solutions

    Energy Technology Data Exchange (ETDEWEB)

    Wazwaz, Abdul-Majid, E-mail: wazwaz@sxu.ed [Department of Mathematics, Saint Xavier University, Chicago, IL 60655 (United States)

    2010-08-15

    Combined equations of the Burgers hierarchy are constructed using the sense of the combined Korteweg-de Vries (KdV)-modified KdV (mKdV) equation. The Cole-Hopf transformation method is used to study the resulting equations. Multiple kink solutions and multiple singular kink solutions are formally established for each combined equation. The kink solutions of any combination differ only in the dispersion relation.

  16. Comparison of Spectral and Differential Quadrature Methods for Solving the Burger-Huxley Equation

    Directory of Open Access Journals (Sweden)

    Jalal Izadian

    2013-06-01

    Full Text Available In this paper, the Burger-Huxley equation is solved by two methods: Spectral method and Differential Quadrature Method (DQM. The Chebyshev-Gauss-Lobatto point distribution is utilized in spectral method. The integrity and computational accuracy of the spectral method in solving some test problems are demonstrated through various case studies. The results show that spectral method is more accurate than DQM.

  17. New multiple-soliton (kink) solutions for the high-order Boussinesq-Burgers equation

    Science.gov (United States)

    Guo, Peng; Wu, Xiang; Wang, Liangbi

    2016-07-01

    The homogeneous balance method is extended to find more new solutions of nonlinear evolution equations. As illustrative examples, many new multiple-soliton (kink) solutions of the high-order Boussinesq-Burgers equation are constructed. It is shown that the homogeneous balance method may provide us with a straightforward and effective mathematic tool for generating new multiple-soliton (kink) solutions of nonlinear evolution equations.

  18. Bifurcation and Solitary-Like Solutions for Compound KdV-Burgers-Type Equation

    Directory of Open Access Journals (Sweden)

    Yin Li

    2015-01-01

    Full Text Available Firstly, based on the improved sub-ODE method and the bifurcation method of dynamical systems, we investigate the bifurcation of solitary waves in the compound KdV-Burgers-type equation. Secondly, numbers of solitary patterns solutions are given for each parameter condition and numerical simulations are used to display the dynamical characteristics. Finally, we obtain twelve solitary patterns solutions under some parameter conditions, such as the trigonometric function solutions and the hyperbolic function solutions.

  19. New exact solutions of the non-homogeneous Burgers equation in (1+1) dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Schulze-Halberg, Axel [Department of Science, University of Colima, Bernal Diaz del Castillo 340, Colima Villas San Sebastian, C P 28045, Colima (Mexico)

    2007-04-15

    We construct an invertible transformation between the non-homogeneous Burgers equation (NBE) and the stationary Schroedinger equation in (1+1) dimensions. By means of this transformation, each solution of the stationary Schroedinger equation generates a fully time-dependent solution of the NBE. As applications we derive exact solutions of the NBE for general power-law nonhomogeneities, generalizing former results on the linear case.

  20. Conservation laws and exact solutions of system of Boussinesq-Burgers equations

    Science.gov (United States)

    Akbulut, Arzu; Kaplan, Melike; Taşcan, Filiz

    2017-01-01

    In this work, we study conservation laws that is one of the applications of symmetries. Conservation laws has important place for differential equations and their solutions, also in all physics applications. This study deals with conservation laws of Boussinessq-Burgers equation. We used Noether approach and conservation theorem approach for finding conservation laws for this equation. Also finally, we found exact solutions of this equation by using the modified simple equation method.

  1. Development of Galerkin Method for Solving the Generalized Burger's-Huxley Equation

    Directory of Open Access Journals (Sweden)

    M. El-Kady

    2013-01-01

    Full Text Available Numerical treatments for the generalized Burger's—Huxley GBH equation are presented. The treatments are based on cardinal Chebyshev and Legendre basis functions with Galerkin method. Gauss quadrature formula and El-gendi method are used to convert the problem into a system of ordinary differential equations. The numerical results are compared with the literatures to show efficiency of the proposed methods.

  2. Anomalous scaling in the random-force-driven Burgers equation. A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Mesterhazy, David [TU Darmstadt (Germany). Inst. fuer Kernphysik; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann Inst. fuer Computing

    2011-12-15

    We present a new approach to determine the small-scale statistical behavior of hydrodynamic turbulence by means of lattice simulations. Using the functional integral representation of the random-force-driven Burgers equation we show that high-order moments of velocity differences satisfy anomalous scaling. The general applicability of Monte Carlo methods provides the opportunity to study also other systems of interest within this framework. (orig.)

  3. EXTENSION TO THE DIRECT METHODS AND APPLICATIONS TO THE GENERALIZED BURGERS EQUATION

    Institute of Scientific and Technical Information of China (English)

    ZhangQuanju; FengFuye

    2002-01-01

    A generalization of the direct method of Clarkson and Kruskal for finding similarity reductions of partial differential equations with arbitrary functions is found and discussed for the generalized Burgers equation. The corresponding reductions and the exact solutions due to the methods of the ordinary differential equations are then given by the methods. The results given here answer partially an open problem proposed by Clarkson, that is how to develop the direct method to seek symmetry reductions of nonlinear PDEs with arbitrary functions.

  4. On multi-graded-index soliton solutions for the Boussinesq-Burgers equations in optical communications

    Science.gov (United States)

    Abdel-Gawad, H. I.; Tantawy, M.

    2017-02-01

    Very recently, multi-solitary long waves for the homogeneous Boussinesq-Burgers equations (BBEs) were studied. Here its found that the time dependent coefficients (BBEs), shows multi-graded-index solitons waves, which are graded refractive index profile and can offer a new route for high-power lasers and transmission. They should increase data rates in low-cost telecommunications systems. Further, that (BBEs) show long periodic solitons waves in communications and television antennas.

  5. Numerical Computation of the Tau Approximation for the Delayed Burgers Equation

    Science.gov (United States)

    Khaksar, Haghani F.; Karimi, Vanani S.; Sedighi, Hafshejani J.

    2013-02-01

    We investigate an efficient extension of the operational Tau method for solving the delayed Burgers equation(DBE) arising in physical problems. This extension gives a useful numerical algorithm for the DBE including linear and nonlinear terms. The orthogonality of the Laguerre polynomials as the basis function is the main characteristic behind the method to decrease the volume of computations and runtime of the method. Numerical results are also presented for some experiments to demonstrate the usefulness and accuracy of the proposed algorithm.

  6. Exact Solutions of Fractional Burgers and Cahn-Hilliard Equations Using Extended Fractional Riccati Expansion Method

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-01-01

    Full Text Available Based on a general fractional Riccati equation and with Jumarie’s modified Riemann-Liouville derivative to an extended fractional Riccati expansion method for solving the time fractional Burgers equation and the space-time fractional Cahn-Hilliard equation, the exact solutions expressed by the hyperbolic functions and trigonometric functions are obtained. The obtained results show that the presented method is effective and appropriate for solving nonlinear fractional differential equations.

  7. New Travelling Wave Solutions to Compound KdV-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    YU Jun; KE Yun-Quan; ZHANG Wei-Jun

    2004-01-01

    The compound KdV-Burgers equation and combined KdV-mKdV equation are real physical models concerning many branches in physics.In this paper,applying the improved trigonometric function method to these equations,rich explicit and exact travelling wave solutions,which contain solitary-wave solutions,periodic solutions,and combined formal solitary-wave solutions,are obtained.

  8. Embed-Solitons and Their Evolutional Behaviors of (3+1)-Dimensional Burgers System

    Institute of Scientific and Technical Information of China (English)

    ZHU Hai-Ping; ZHENG Chun-Long

    2007-01-01

    With the help of an extended mapping approach and a linear variable separation method, new families of variable separation solutions with arbitrary functions for the (3+1)-dimensional Burgers system are derived. Based on thc derived exact solutions, some novel and interesting localized coherent excitations such as embed-solitons are revealed by selecting appropriate boundary conditions and/or initial qualifications. The time evolutional properties of the novel localized excitation are also briefly investigated.

  9. KdV-Burgers equation in the modified continuum model considering anticipation effect

    Science.gov (United States)

    Liu, Huaqing; Zheng, Pengjun; Zhu, Keqiang; Ge, Hongxia

    2015-11-01

    The new continuum model mentioned in this paper is developed based on optimal velocity car-following model, which takes the drivers' anticipation effect into account. The critical condition for traffic flow is derived, and nonlinear analysis shows density waves occur in traffic flow because of the small disturbance. Near the neutral stability line, the KdV-Burgers equation is derived and one of the solutions is given. Numerical simulation is carried out to show the local cluster described by the model.

  10. Soliton solutions of the two-dimensional KdV-Burgers equation by homotopy perturbation method

    Energy Technology Data Exchange (ETDEWEB)

    Molabahrami, A. [Department of Mathematics, Ilam University, PO Box 69315516, Ilam (Iran, Islamic Republic of)], E-mail: a_m_bahrami@yahoo.com; Khani, F. [Department of Mathematics, Ilam University, PO Box 69315516, Ilam (Iran, Islamic Republic of); Bakhtar Institute of Higher Education, PO Box 696, Ilam (Iran, Islamic Republic of)], E-mail: farzad_khani59@yahoo.com; Hamedi-Nezhad, S. [Bakhtar Institute of Higher Education, PO Box 696, Ilam (Iran, Islamic Republic of)

    2007-10-29

    In this Letter, the He's homotopy perturbation method (HPM) to finding the soliton solutions of the two-dimensional Korteweg-de Vries Burgers' equation (tdKdVB) for the initial conditions was applied. Numerical solutions of the equation were obtained. The obtained solutions, in comparison with the exact solutions admit a remarkable accuracy. The results reveal that the HPM is very effective and simple.

  11. Effect of turmeric powder (Curcuma longa L.) and ascorbic acid on physical characteristics and oxidative status of fresh and stored rabbit burgers.

    Science.gov (United States)

    Mancini, Simone; Preziuso, Giovanna; Dal Bosco, Alessandro; Roscini, Valentina; Szendrő, Zsolt; Fratini, Filippo; Paci, Gisella

    2015-12-01

    The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgers with 3.5 g of turmeric powder/100g meat; burgers with 0.1g of ascorbic acid/100g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers.

  12. Lattice Boltzmann Model for Compound Burgers-Korteweg-de Vries Equation%Burgers-Korteweg-de Vries 复合方程的格子Boltzmann方法模拟

    Institute of Scientific and Technical Information of China (English)

    段雅丽; 陈先进; 孔令华

    2015-01-01

    We develop a lattice Boltzmann model for compound Burgers-Korteweg-de Vries ( cBKdV) equation. By properly treating dispersive term uxxx and applying Chapman-Enskog expansion, the governing equation is recovered correctly from lattice Boltzmann equation and local equilibrium distribution functions are obtained. Numerical experiments show that our results agree well with exact solutions and have better numerical accuracy compared with previous numerical results. This hence indicates that the model is satisfactory and efficient.%针对Burgers-Korteweg-de Vries ( cBKdV)复合方程提出一种格子Boltzmann模型。通过恰当地处理色散项uxxx 并运用Chapman-Enskog展开从格子Boltzmann方程推导出宏观方程,从而得到联系微观量与宏观量的局部平衡分布函数。对不同微分方程进行数值实验,数值解与解析解非常吻合,相比于其它数值结果,该格子Boltzmann模型的数值结果更精确,说明该数值模型的高效性。

  13. Existence and uniqueness of entropy solution to initial boundary value problem for the inviscid Burgers equation

    Science.gov (United States)

    Zhu, Changjiang; Duan, Renjun

    2003-02-01

    This paper is concerned with the existence and uniqueness of the entropy solution to the initial boundary value problem for the inviscid Burgers equation \\left\\{\\begin{array}{@{}l@{\\qquad}l@{}} u_t+\\big(\\frac{u^2}{2}\\big)_x=0 x\\gt0\\quad t\\gt0\\\\ u(x,0)=u_0(x) x\\geq0\\\\ u(0,t)=0 t\\geq0. \\end{array}\\right. To apply the method of vanishing viscosity to study the existence of the entropy solution, we first introduce the initial boundary value problem for the viscous Burgers equation, and as in Evans (1998 Partial Differential Equations (Providence, RI: American Mathematical Society) and Hopf (1950 Commun. Pure Appl. Math. 3 201-30), give the formula of the corresponding viscosity solutions by Hopf-Cole transformation. Secondly, we prove the convergence of the viscosity solution sequences and verify that the limiting function is an entropy solution. Finally, we give an example to show how our main result can be applied to solve the initial boundary value problem for the Burgers equation.

  14. Approximate Damped Oscillatory Solutions for Compound KdV-Burgers Equation and Their Error Estimates

    Institute of Scientific and Technical Information of China (English)

    Wei-guo ZHANG; Yan ZHAO; Xiao-yan TENG

    2012-01-01

    In this paper,we focus on studying approximate solutions of damped oscillatory solutions of the compound KdV-Burgers equation and their error estimates.We employ the theory of planar dynamical systems to study traveling wave solutions of the compound KdV-Burgers equation.We obtain some global phase portraits under different parameter conditions as well as the existence of bounded traveling wave solutions.Furthermore,we investigate the relations between the behavior of bounded traveling wave solutions and the dissipation coefficient r of the equation.We obtain two critical values of r,and find that a bounded traveling wave appears as a kink profile solitary wave if |r| is greater than or equal to some critical value,while it appears as a damped oscillatory wave if |r| is less than some critical value.By means of analysis and the undetermined coefficients method,we find that the compound KdV-Burgers equation only has three kinds of bell profile solitary wave solutions without dissipation.Based on the above discussions and according to the evolution relations of orbits in the global phase portraits,we obtain all approximate damped oscillatory solutions by using the undetermined coefficients method.Finally,using the homogenization principle,we establish the integral equations reflecting the relations between exact solutions and approximate solutions of damped oscillatory solutions.Moreover,we also give the error estimates for these approximate solutions.

  15. My 2030s. Citizens about the Biobased Economy; My 2030s. Burgers over de Biobased Economy

    Energy Technology Data Exchange (ETDEWEB)

    Van den Berg, N.; Hulshof, M.; Van der Veen, M.

    2013-02-15

    My 2030s is the first qualitative study of the needs and concerns of citizens about the Biobased Economy, an economy in which fossil fuels are largely substituted by vegetable alternatives. This final report describes the reason and purpose of My 2030s, the course of the public debates and the results of research into ideas of citizens on the Biobased Economy The report concludes with recommendations on how the stakeholders can actively involve citizens in one of the major transitions of the next century [Dutch] My 2030s is het eerste kwalitatieve onderzoek naar de wensen en zorgen van burgers over de Biobased Economy, een economie waarin fossiele grondstoffen grotendeels zijn vervangen door plantaardige alternatieven. Dit eindrapport beschrijft de aanleiding en opzet van My 2030s, het verloop van de publieksdebatten en de resultaten van het onderzoek naar denkbeelden van burgers over de Biobased Economy. Het rapport eindigt met aanbevelingen over hoe de stakeholders burgers actief kunnen betrekken bij een van de belangrijkste transities van de komende eeuw.

  16. On the multivariate Burgers equation and the incompressible Navier-Stokes equation

    CERN Document Server

    Kampen, Joerg

    2009-01-01

    We prove global existence of the multivariate viscous Burgers equation system defined on the whole space or on a domain isomorphic to the $n$-torus and with time horizon up to infinity and $C^{\\infty}$- data (satisfying some growth conditions if the problem is posed on the whole space). The proof is by a semi-explicit perturbative expansion in transformed coordinates where the convergence is guaranteed by certain a priori estimates. Under some moderate conditions uniqueness of the global solution of the multivariate Burgers equation is a consequence of uniqueness of solutions of a semilinear system. The global solution ${\\bf u}$ constructed is H\\"older continuous and serves to define coefficients of a system which is linear in terms of ${\\bf u}$. The fundamental solution of the latter system is called the fundamental functional and is dependent on the initial data of the Burgers problem in a generic way. The fundamental functional proves useful in order to construct solutions for a class of semilinear partial...

  17. Vector analysis

    CERN Document Server

    Brand, Louis

    2006-01-01

    The use of vectors not only simplifies treatments of differential geometry, mechanics, hydrodynamics, and electrodynamics, but also makes mathematical and physical concepts more tangible and easy to grasp. This text for undergraduates was designed as a short introductory course to give students the tools of vector algebra and calculus, as well as a brief glimpse into these subjects' manifold applications. The applications are developed to the extent that the uses of the potential function, both scalar and vector, are fully illustrated. Moreover, the basic postulates of vector analysis are brou

  18. New explicit exact solutions to a type of generalized Burgers-KdV equations with variant coefficients%具有变系数的广义Burgers-KdV方程新精确解

    Institute of Scientific and Technical Information of China (English)

    赵熙强; 张玉峰; 闫庆友; 龚新波

    2003-01-01

    Truncation expansion method is used to obtain new explicit exact solutions to a type of generalized Burgers-KdV equations with variant coefficients. As special reduction cases, the exact solutions for the generalized KdV equation and the generalized cylinder KdV equation with variant coefficients are presented respectively; and thereafter a new explicit exact solitary solution for the well-known Burgers equation is shown, which was not found before.%利用截断展开法求得了具有变系数的一类广义Burgers-KdV方程的新的精确解. 作为特例, 分别获得了具有变系数的广义KdV方程和广义柱KdV方程的精确解. 由此发现了Burgers方程的一类新的孤子解.

  19. Impact of Nisin-Activated Packaging on Microbiota of Beef Burgers during Storage.

    Science.gov (United States)

    Ferrocino, Ilario; Greppi, Anna; La Storia, Antonietta; Rantsiou, Kalliopi; Ercolini, Danilo; Cocolin, Luca

    2015-11-06

    Beef burgers were stored at 4°C in a vacuum in nisin-activated antimicrobial packaging. Microbial ecology analyses were performed on samples collected between days 0 and 21 of storage to discover the population diversity. Two batches were analyzed using RNA-based denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. The active packaging retarded the growth of the total viable bacteria and lactic acid bacteria. Culture-independent analysis by pyrosequencing of RNA extracted directly from meat showed that Photobacterium phosphoreum, Lactococcus piscium, Lactobacillus sakei, and Leuconostoc carnosum were the major operational taxonomic units (OTUs) shared between control and treated samples. Beta diversity analysis of the 16S rRNA sequence data and RNA-DGGE showed a clear separation between two batches based on the microbiota. Control samples from batch B showed a significant high abundance of some taxa sensitive to nisin, such as Kocuria rhizophila, Staphylococcus xylosus, Leuconostoc carnosum, and Carnobacterium divergens, compared to control samples from batch A. However, only from batch B was it possible to find a significant difference between controls and treated samples during storage due to the active packaging. Predicted metagenomes confirmed differences between the two batches and indicated that the use of nisin-based antimicrobial packaging can determine a reduction in the abundance of specific metabolic pathways related to spoilage. The present study aimed to assess the viable bacterial communities in beef burgers stored in nisin-based antimicrobial packaging, and it highlights the efficacy of this strategy to prolong beef burger shelf life.

  20. Cloning vector

    Science.gov (United States)

    Guilfoyle, Richard A.; Smith, Lloyd M.

    1994-01-01

    A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site.

  1. Effect of turmeric powder (Curcuma longa L. and ascorbic acid on antioxidant capacity and oxidative status in rabbit burgers after cooking

    Directory of Open Access Journals (Sweden)

    S. Mancini

    2016-06-01

    Full Text Available The aim of this study was to evaluate the effects of turmeric powder and ascorbic acid on lipid oxidation and antioxidant capacity in cooked rabbit burgers. The burgers were derived from 3 different formulations (C, control, with no additives; Tu with 3.5% of turmeric powder and AA with 0.1% of ascorbic acid and were stored at 4°C for 0 and 7 d and cooked. The lipid oxidation (thiobarbituric acid reactive substances [TBARS] and antioxidant capacity (2,2-azinobis-[3 ethylbenzothiazoline-6-sulfonic acid] {ABTS}, 1,1-diphenyl-2-pircydrazyl [DPPH] and ferric reducing ability [FRAP] were evaluated. A significant interaction between storage time and formulation (P<0.001 was observed for DPPH, FRAP and TBARS in cooked burgers. At day 0 and day 7, the DPPH value was higher in Tu and AA compared to C burgers. At day 0, C showed a lower level of FRAP than the Tu and AA burgers. At day 7, the FRAP values tended to decrease but remained significantly higher in Tu and AA compared to C burgers. Lipid oxidation at day 0 in Tu and AA showed lower TBARS values compared to C burgers. The addition of 3.5% turmeric powder in rabbit burgers exerts an antioxidant effect during storage and it seems more effective in controlling lipid oxidation than ascorbic acid after cooking.

  2. Numerical solution of two dimensional coupled viscous Burger equation using modified cubic B-spline differential quadrature method

    Directory of Open Access Journals (Sweden)

    H. S. Shukla

    2014-11-01

    Full Text Available In this paper, a numerical solution of two dimensional nonlinear coupled viscous Burger equation is discussed with appropriate initial and boundary conditions using the modified cubic B-spline differential quadrature method. In this method, the weighting coefficients are computed using the modified cubic B-spline as a basis function in the differential quadrature method. Thus, the coupled Burger equation is reduced into a system of ordinary differential equations. An optimal five stage and fourth-order strong stability preserving Runge–Kutta scheme is applied for solving the resulting system of ordinary differential equations. The accuracy of the scheme is illustrated by taking two numerical examples. Computed results are compared with the exact solutions and other results available in literature. Obtained numerical result shows that the described method is efficient and reliable scheme for solving two dimensional coupled viscous Burger equation.

  3. Juiciness improvement of frozen battered shrimp burger using modified tapioca starch, sodium alginate, and iota-carrageenan

    Directory of Open Access Journals (Sweden)

    Kongkarn Kijroongrojana

    2009-11-01

    Full Text Available A battered shrimp burger, as a new value-added shrimp product, was developed by increasing the juiciness of a frozen battered shrimp burger using a mixture of hydrocolloids. The formulations of hydrocolloid mixtures containing modified tapioca starch (MTS, sodium alginate (AL, and iota-carrageenan (CA were optimized. Juiciness measurements were defined and analyzed by 13 trained panelists. Texture Profile Analysis (TPA as well as moisture and fat contents of the products were analyzed. The mixture of MTS and AL had an impact on moisture content and juiciness scores, while CA influenced the hardness. The product made using the optimized formulation (0.3% MTS + 0.7% AL had a higher moisture content andjuiciness scores (p0.05. However, higher springiness and gumminess were found in the control burger (p0.05.

  4. Sinc and solitary wave solutions to the generalized Benjamin-Bona-Mahony-Burgers equations

    Energy Technology Data Exchange (ETDEWEB)

    Alqruan, Marwan; Al-Khaled, Kamel, E-mail: marwan04@just.edu.jo, E-mail: kamel@just.edu.jo [Department of Mathematics and Statistics, Jordan University of Science and Technology, Irbid 22110 (Jordan)

    2011-06-01

    In this paper, we consider the generalized Benjamin-Bona-Mahony-Burgers (BBMB) equations. A variety of exact solutions to the BBMB equations are developed by means of the tanh method. A sinc-Galerkin procedure is also developed to solve the BBMB equations. Sinc approximations to both the derivatives and the indefinite integrals reduce the system to an explicit system of algebraic equations. It is shown that sinc-Galerkin approximations produce an error of exponential order. A comparison of the two methods for solving the BBMB equation was made regarding their solutions. The study outlines the features of the sinc method.

  5. Embedded-Soliton and Complex Wave Excitations of (3+1)-Dimensional Burgers System

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ren; ZHU Hai-Ping; ZHANG Li-Chun; PAN Zhen-Huan; WU Yue-Qin; ZHENG Chun-Long; LI Huai-Fan

    2008-01-01

    Starting from the extended mapping approach and a linear variable separation method, we find new families of variable separation solutions with some arbitrary functions for the (3+1 )-dimensional Burgers system. Then based on the derived exact solutions, some novel and interesting localized coherent excitations such as embedded-solitons, taper-like soliton, complex wave excitations in the periodic wave background are revealed by introducing appropriate boundary conditions and/or initial qualifications. The evolutional properties of the complex wave excitations are briefly investigated.

  6. Exact Solutions for an MHD Generalized Burgers fluid: Stokes' Second Problem

    CERN Document Server

    Khan, Masood; Anjum, Asia

    2013-01-01

    This paper offers the exact analytical solutions for the magnetohydrodynamic (MHD) flow of an incompressible generalized Burgers fluid corresponding to the second problem of Stokes in the presence of the transverse magnetic field. Modified Darcy's law has been taken into account. The expression for the velocity field and associated tangential stress, presented as a sum of the steady-state and transient solutions, are obtained by means of the integral transforms. Moreover, several figures are plotted to investigate the effects of various emerging parameters on the velocity field. The obtained results show that the magnitude of the velocity and boundary layer thickness significantly reduce in the presence of magnetic field.

  7. Nonequivalent Similarity Reductions and Exact Solutions for Coupled Burgers-Type Equations

    Science.gov (United States)

    M. H. M., Moussa; R. A. K., Omar; Rehab, M. El-Shiekh; H. R., El-Melegy

    2012-01-01

    Using the machinery of Lie group analysis, the nonlinear system of coupled Burgers-type equations is studied. Using the infinitesimal generators in the optimal system of subalgebra of the said Lie algebras, it leads to two nonequivalent similarity transformations by using it we obtain two reductions in the form of system of nonlinear ordinary differential equations. The search for solutions of these systems by using the G'/G-method has yielded certain exact solutions expressed by rational functions, hyperbolic functions, and trigonometric functions. Some figures are given to show the properties of the solutions.

  8. 2D Zakharov-Kuznetsov-Burgers equations with variable dissipation on a strip

    Directory of Open Access Journals (Sweden)

    Nikolai A. Larkin

    2015-03-01

    Full Text Available An initial-boundary value problem for a 2D Zakharov-Kuznetsov-Burgers type equation with dissipation located in a neighborhood of $x=-\\infty$ and posed on a channel-type strip was considered. The existence and uniqueness results for regular and weak solutions in weighted spaces as well as exponential decay of small solutions without restrictions on the width of a strip were proven both for regular solutions in an elevated norm and for weak solutions in the $L^2$-norm.

  9. Strong obstruction of the Berends-Burgers-van Dam spin-3 vertex

    Energy Technology Data Exchange (ETDEWEB)

    Bekaert, Xavier [Laboratoire de Mathematiques et Physique Theorique, Unite Mixte de Recherche 6083 du CNRS, Federation de Recherche 2964 Denis Poisson, Universite Fran cois Rabelais, Parc de Grandmount, 37200 Tours (France); Boulanger, Nicolas; Leclercq, Serge, E-mail: Xavier.Bekaert@lmpt.univ-tours.f, E-mail: nicolas.boulanger@umons.ac.b, E-mail: serge.leclercq@umons.ac.b [Service de Mecanique et Gravitation, Universite de Mons-UMONS, 20 Place du Parc, 7000 Mons (Belgium)

    2010-05-07

    In the 1980s, Berends, Burgers and van Dam (BBvD) found a nonabelian cubic vertex for self-interacting massless fields of spin three in flat spacetime. However, they also found that this deformation is inconsistent at higher orders for any multiplet of spin-3 fields. For arbitrary symmetric gauge fields, we severely constrain the possible nonabelian deformations of the gauge algebra and, using these results, prove that the BBvD obstruction cannot be cured by any means, even by introducing fields of spin that are higher (or lower) than 3.

  10. On the BBM-Burgers Equation: Well-posedness, Ill-posedness and Long Period Limit

    CERN Document Server

    Brango, Carlos Banquet

    2011-01-01

    In this work we study a dispersive equation with a dissipative term, the Benjamin-Bona-Mahony-Burgers equation. First we prove that the initial value problem for this equation is well-posed in $H^s(\\mathbb{R}),$ for $s\\geq 0$ and ill-posed if $s< 0.$ The ill-posedness is in the sense that the flow-map cannot be continuous at the origin from $H^s(\\mathbb{R})$ to even $\\mathcal{D}'(\\mathbb{R}).$ Additionally, we establish an exact theory of convergence of the periodic solutions to the continuous one, in Sobolev spaces, as the period goes to infinity.

  11. A new Riccati equation rational expansion method and its application to (2 + 1)-dimensional Burgers equation

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qi [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200030 (China); Chen Yong [M.M. Key Lab, Chinese Academy of Sciences, Beijing 100080 (China); Nonlinear Science Center and Department of Mathematics, Ningbo University, Ningbo 315211 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200030 (China); E-mail: chenyong@dlut.edu.cn; Zhang Hongqing [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2005-09-01

    In this paper, we present a new Riccati equation rational expansion method to uniformly construct a series of exact solutions for nonlinear evolution equations. Compared with most existing tanh methods and other sophisticated methods, the proposed method not only recover some known solutions, but also find some new and general solutions. The solutions obtained in this paper include rational triangular periodic wave solutions, rational solitary wave solutions and rational wave solutions. The efficiency of the method can be demonstrated on (2 + 1)-dimensional Burgers equation.

  12. Nonequivalent Similarity Reductions and Exact Solutions for Coupled Burgers-Type Equations

    Institute of Scientific and Technical Information of China (English)

    M.H.M. Moussa; R.A.K. Omar; Rehab M. El-Shiekh; H.R. El-Melegy

    2012-01-01

    Using the machinery of Lie group analysis, the nonlinear system of coupled Burgers-type equations is studied. Using the infinitesimal generators in the optimal system of subalgebra of the said Lie algebras, it leads to two nonequivalent similarity transformations by using it we obtain two reductions in the form of system of nonlinear ordinary differential equations. The search for solutions of these systems by using the G/G-method has yielded certain exact solutions expressed by rational functions, hyperbolic functions, and trigonometric functions. Some figures are given to show the properties of the solutions.

  13. Interactions among special embed-solitons for the (3+1)-dimensional Burgers equation

    Institute of Scientific and Technical Information of China (English)

    Zhang Wen-Ting; Dai Chao-Qing; Chen Wei-Lu

    2013-01-01

    With the help of a modified mapping method and a new mapping method,we re-study the (3+ 1)-dimensional Burgers equation,and derive two families of variable separation solutions.By selecting appropriate functions in the variable separation solution,we discuss the interaction behaviors among taper-like,plateau-type rings,and rectangle-type embed-solitons in the periodic wave background.All the interaction behaviors are completely elastic,and no phase shift appears after interaction.

  14. Painlevé property, symmetries and symmetry reductions of the coupled Burgers system

    Institute of Scientific and Technical Information of China (English)

    Lian Zeng-Ju; Chen Li-Li; Lou Sen-Yue

    2005-01-01

    The Painlevé property, inverse recursion operator, infinite number of symmetries and Lie symmetry reductions of the coupled Burgers equation are given explicitly. Three sets of infinitely many symmetries of the considered model are obtained by acting the recursion operator and the inverse recursion operator on the trivial symmetries such as the identity transformation, the space translation and the scaling transformation respectively. These symmetries constitute an infinite dimensional Lie algebra while its finite dimensional Lie point symmetry subalgebra is used to find possible symmetry reductions and then the group invariant solutions.

  15. A NEW VISCOUS REGULARIZATION OF THE RIEMANN PROBLEM FOR BURGERS' EQUATION

    Institute of Scientific and Technical Information of China (English)

    Wang Jinghua; Zhang Hui

    2000-01-01

    This paper gives a new viscous regularization of the Riemann problem for Burgers' equation ut += 0 with Riemann initial data u = u_(x _< 0),u =u+(x > 0) at t = 0. The regularization is given by ut += εetuxx with appropriate initial data. The method is different from the classical method, through comparison of three viscous equations of it. Here it is also shown that the difference of the three regularizations approaches zero in appropriate integral norms depending on the data as ε → 0+ for any given T > 0.

  16. Light propagation in a Cole-Cole nonlinear medium via Burgers-Hopf equation

    OpenAIRE

    Konopelchenko, Boris; Moro, Antonio

    2004-01-01

    Recently, a new model of propagation of the light through the so-called weakly three-dimensional Cole-Cole nonlinear medium with short-range nonlocality has been proposed. In particular, it has been shown that in the geometrical optics limit, the model is integrable and it is governed by the dispersionless Veselov-Novikov (dVN) equation. Burgers-Hopf equation can be obtained as 1+1-dimensional reduction of dVN equation. We discuss its properties in the specific context of nonlinear geometrica...

  17. Two different methods for numerical solution of the modified Burgers' equation.

    Science.gov (United States)

    Karakoç, Seydi Battal Gazi; Başhan, Ali; Geyikli, Turabi

    2014-01-01

    A numerical solution of the modified Burgers' equation (MBE) is obtained by using quartic B-spline subdomain finite element method (SFEM) over which the nonlinear term is locally linearized and using quartic B-spline differential quadrature (QBDQM) method. The accuracy and efficiency of the methods are discussed by computing L 2 and L ∞ error norms. Comparisons are made with those of some earlier papers. The obtained numerical results show that the methods are effective numerical schemes to solve the MBE. A linear stability analysis, based on the von Neumann scheme, shows the SFEM is unconditionally stable. A rate of convergence analysis is also given for the DQM.

  18. Evolution Property of Multisoliton Excitations for a Higher-Dimensional Coupled Burgers System

    Institute of Scientific and Technical Information of China (English)

    ZHENG Chun-Long; FANG Jian-Ping; CHEN Li-Qun

    2004-01-01

    By means of the standard truncated Painleve expansion and a special Backlund transformation, the higher dimensional coupled Burgers system (HDCB) is reduced to a linear equation, and an exact multisoliton excitation is derived. The evolution properties of the multisoliton excitation are investigated and some novel features or interesting behaviors are revealed. The results show that after interactions for dromion-dromion, solitoff-solitoff, and solitoffdromion, they are combined with some new types of localized structures, which are similar to classic particles with completely nonelastic behaviors.

  19. A Modified Three-Level Average Linear-Implicit Finite Difference Method for the Rosenau-Burgers Equation

    Directory of Open Access Journals (Sweden)

    Jiraporn Janwised

    2014-01-01

    Full Text Available We introduce a new technique, a three-level average linear-implicit finite difference method, for solving the Rosenau-Burgers equation. A second-order accuracy on both space and time numerical solution of the Rosenau-Burgers equation is obtained using a five-point stencil. We prove the existence and uniqueness of the numerical solution. Moreover, the convergence and stability of the numerical solution are also shown. The numerical results show that our method improves the accuracy of the solution significantly.

  20. New analytical method for solving Burgers' and nonlinear heat transfer equations and comparison with HAM

    Science.gov (United States)

    Rashidi, M. M.; Erfani, E.

    2009-09-01

    In this study, we present a numerical comparison between the differential transform method (DTM) and the homotopy analysis method (HAM) for solving Burgers' and nonlinear heat transfer problems. The first differential equation is the Burgers' equation serves as a useful model for many interesting problems in applied mathematics. The second one is the modeling equation of a straight fin with a temperature dependent thermal conductivity. In order to show the effectiveness of the DTM, the results obtained from the DTM is compared with available solutions obtained using the HAM [M.M. Rashidi, G. Domairry, S. Dinarvand, Commun. Nonlinear Sci. Numer. Simul. 14 (2009) 708-717; G. Domairry, M. Fazeli, Commun. Nonlinear Sci. Numer. Simul. 14 (2009) 489-499] and whit exact solutions. The method can easily be applied to many linear and nonlinear problems. It illustrates the validity and the great potential of the differential transform method in solving nonlinear partial differential equations. The obtained results reveal that the technique introduced here is very effective and convenient for solving nonlinear partial differential equations and nonlinear ordinary differential equations that we are found to be in good agreement with the exact solutions.

  1. Entropy Stable Staggered Grid Spectral Collocation for the Burgers' and Compressible Navier-Stokes Equations

    Science.gov (United States)

    Carpenter, Mark H.; Parsani, Matteo; Fisher, Travis C.; Nielsen, Eric J.

    2015-01-01

    Staggered grid, entropy stable discontinuous spectral collocation operators of any order are developed for Burgers' and the compressible Navier-Stokes equations on unstructured hexahedral elements. This generalization of previous entropy stable spectral collocation work [1, 2], extends the applicable set of points from tensor product, Legendre-Gauss-Lobatto (LGL) to a combination of tensor product Legendre-Gauss (LG) and LGL points. The new semi-discrete operators discretely conserve mass, momentum, energy and satisfy a mathematical entropy inequality for both Burgers' and the compressible Navier-Stokes equations in three spatial dimensions. They are valid for smooth as well as discontinuous flows. The staggered LG and conventional LGL point formulations are compared on several challenging test problems. The staggered LG operators are significantly more accurate, although more costly to implement. The LG and LGL operators exhibit similar robustness, as is demonstrated using test problems known to be problematic for operators that lack a nonlinearly stability proof for the compressible Navier-Stokes equations (e.g., discontinuous Galerkin, spectral difference, or flux reconstruction operators).

  2. Burgers equation with no-flux boundary conditions and its application for complete fluid separation

    Science.gov (United States)

    Watanabe, Shinya; Matsumoto, Sohei; Higurashi, Tomohiro; Ono, Naoki

    2016-09-01

    Burgers equation in a one-dimensional bounded domain with no-flux boundary conditions at both ends is proven to be exactly solvable. Cole-Hopf transformation converts not only the governing equation to the heat equation with an extra damping but also the nonlinear mixed boundary conditions to Dirichlet boundary conditions. The average of the solution v bar is conserved. Consequently, from an arbitrary initial condition, solutions converge to the equilibrium solution which is unique for the given v bar. The problem arises naturally as a continuum limit of a network of certain micro-devices. Each micro-device imperfectly separates a target fluid component from a mixture of more than one component, and its input-output concentration relationships are modeled by a pair of quadratic maps. The solvability of the initial boundary value problem is used to demonstrate that such a network acts as an ideal macro-separator, separating out the target component almost completely. Another network is also proposed which leads to a modified Burgers equation with a nonlinear diffusion coefficient.

  3. The KdV—Burgers equation in a modified speed gradient continuum model

    Science.gov (United States)

    Lai, Ling-Ling; Cheng, Rong-Jun; Li, Zhi-Peng; Ge, Hong-Xia

    2013-06-01

    Based on the full velocity difference model, Jiang et al. put forward the speed gradient model through the micro-macro linkage (Jiang R, Wu Q S and Zhu Z J 2001 Chin. Sci. Bull. 46 345 and Jiang R, Wu Q S and Zhu Z J 2002 Trans. Res. B 36 405). In this paper, the Taylor expansion is adopted to modify the model. The backward travel problem is overcome by our model, which exists in many higher-order continuum models. The neutral stability condition of the model is obtained through the linear stability analysis. Nonlinear analysis shows clearly that the density fluctuation in traffic flow leads to a variety of density waves. Moreover, the Korteweg-de Vries—Burgers (KdV—Burgers) equation is derived to describe the traffic flow near the neutral stability line and the corresponding solution for traffic density wave is derived. The numerical simulation is carried out to investigate the local cluster effects. The results are consistent with the realistic traffic flow and also further verify the results of nonlinear analysis.

  4. The KdV-Burgers equation in a modified speed gradient continuum model

    Institute of Scientific and Technical Information of China (English)

    Lai Ling-Ling; Cheng Rong-Jun; Li Zhi-Peng; Ge Hong-Xia

    2013-01-01

    Based on the full velocity difference model,Jiang et al.put forward the speed gradient model through the micromacro linkage (Jiang R,Wu Q S and Zhu Z J 2001 Chin.Sci.Bull.46 345 and Jiang R,Wu Q S and Zhu Z J 2002Trans.Res.B 36 405).In this paper,the Taylor expansion is adopted to modify the model.The backward travel problem is overcome by our model,which exists in many higher-order continuum models.The neutral stability condition of the model is obtained through the linear stability analysis.Nonlinear analysis shows clearly that the density fluctuation in traffic flow leads to a variety of density waves.Moreover,the Korteweg-de Vries-Burgers (KdV-Burgers) equation is derived to describe the traffic flow near the neutral stability line and the corresponding solution for traffic density wave is derived.The numerical simulation is carried out to investigate the local cluster effects.The results are consistent with the realistic traffic flow and also further verify the results of nonlinear analysis.

  5. Vector geometry

    CERN Document Server

    Robinson, Gilbert de B

    2011-01-01

    This brief undergraduate-level text by a prominent Cambridge-educated mathematician explores the relationship between algebra and geometry. An elementary course in plane geometry is the sole requirement for Gilbert de B. Robinson's text, which is the result of several years of teaching and learning the most effective methods from discussions with students. Topics include lines and planes, determinants and linear equations, matrices, groups and linear transformations, and vectors and vector spaces. Additional subjects range from conics and quadrics to homogeneous coordinates and projective geom

  6. Some new exact solutions of Jacobian elliptic function about the generalized Boussinesq equation and Boussinesq-Burgers equation

    Institute of Scientific and Technical Information of China (English)

    Zhang Liang; Zhang Li-Feng; Li Chong-Yin

    2008-01-01

    By using the modified mapping method,we find some new exact solutions of the generalized Boussinesq equation and the Boussinesq-Burgers equation.The solutions obtained in this paper include Jacobian elliptic function solutions,combined Jacobian elliptic function solutions,soliton solutions,triangular function solutions.

  7. Promise and Ontological Ambiguity in the In vitro Meat Imagescape: From Laboratory Myotubes to the Cultured Burger.

    Science.gov (United States)

    Stephens, Neil; Ruivenkamp, Martin

    2016-07-02

    In vitro meat (IVM), also known as cultured meat, involves growing cells into muscle tissue to be eaten as food. The technology had its most high-profile moment in 2013 when a cultured burger was cooked and tasted in a press conference. Images of the burger featured in the international media and were circulated across the Internet. These images-literally marks on a two-dimensional surface-do important work in establishing what IVM is and what it can do. A combination of visual semiotics and narrative analysis shows that images of IVM afford readings of their story that are co-created by the viewer. Before the cultured burger, during 2011, images of IVM fell into four distinct categories: cell images, tissue images, flowcharts, and meat in a dish images. The narrative infrastructure of each image type affords different interpretations of what IVM can accomplish and what it is. The 2013 cultured burger images both draw upon and depart from these image types in an attempt to present IVM as a normal food stuff, and as 'matter in place' when placed on the plate. The analysis of individual images and the collection of images about a certain object or subject-known as the imagescape-is a productive approach to understanding the ontology and promise of IVM and is applicable to other areas of social life.

  8. Promise and Ontological Ambiguity in the In vitro Meat Imagescape: From Laboratory Myotubes to the Cultured Burger

    Science.gov (United States)

    Stephens, Neil; Ruivenkamp, Martin

    2016-01-01

    Abstract In vitro meat (IVM), also known as cultured meat, involves growing cells into muscle tissue to be eaten as food. The technology had its most high-profile moment in 2013 when a cultured burger was cooked and tasted in a press conference. Images of the burger featured in the international media and were circulated across the Internet. These images—literally marks on a two-dimensional surface—do important work in establishing what IVM is and what it can do. A combination of visual semiotics and narrative analysis shows that images of IVM afford readings of their story that are co-created by the viewer. Before the cultured burger, during 2011, images of IVM fell into four distinct categories: cell images, tissue images, flowcharts, and meat in a dish images. The narrative infrastructure of each image type affords different interpretations of what IVM can accomplish and what it is. The 2013 cultured burger images both draw upon and depart from these image types in an attempt to present IVM as a normal food stuff, and as ‘matter in place’ when placed on the plate. The analysis of individual images and the collection of images about a certain object or subject—known as the imagescape—is a productive approach to understanding the ontology and promise of IVM and is applicable to other areas of social life. PMID:27695202

  9. New Multiple Soliton-like Solutions to (3+1)-Dimensional Burgers Equation with Variable Coefficients

    Institute of Scientific and Technical Information of China (English)

    CHENHuai-Tang; ZHANGHong-Qing

    2004-01-01

    A new generalized tanh function method is used for constructing exact travelling wave solutions of nonlinear partial differential equations in a unified way. The main idea of this method is to take full advantage of the Riccati equation, which has more new solutions. More new multiple soliton-like solutions are obtained for the (3+1)-dimensional Burgers equation with variable coefficients.

  10. r-modified Crank-Nicholson difference schemes for one dimensional nonlinear viscous Burgers' equation for an incompressible flow

    Science.gov (United States)

    Ashyralyev, Allaberen; Gambo, Yusuf Ya'u.

    2016-08-01

    The nonlocal boundary value problem for viscous Burgers' equation is considered. Solutions to the 1-D equation are presented numerically by Rothe, Crank-Nicholson and r-modified Crank-Nicholson difference schemes. Matlab codes for all the three schemes are designed based on the idea of fixed-point iteration procedure and modified Gauss elimination method. The numerical results are compared.

  11. Asymptotic Behavior of Solutions to the Generalized BBM-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    Mi-na Jiang; Yan-ling Xu

    2005-01-01

    We investigate the asymptotic behavior of solutions of the initial-boundary value problem for the generalized BBM-Burgers equation ut + f(u)x = uxx +uxxt on the half line with the conditions u(0, t) =u-, u(∞, t) = u+ and u- < u+, where the corresponding Cauchy problem admits the rarefaction wave as an asymptotic states. In the present problem, because of the Dirichlet boundary, the asymptotic states are divided into five cases depending on the signs of the characteristic speeds f′(u±) of boundary state u- = u(0) and the far fields states u+ = u(∞). In all cases both global existence of the solution and asymptotic behavior are shown under the smallness conditions.

  12. A generalized simplest equation method and its application to the Boussinesq-Burgers equation.

    Directory of Open Access Journals (Sweden)

    Bilige Sudao

    Full Text Available In this paper, a generalized simplest equation method is proposed to seek exact solutions of nonlinear evolution equations (NLEEs. In the method, we chose a solution expression with a variable coefficient and a variable coefficient ordinary differential auxiliary equation. This method can yield a Bäcklund transformation between NLEEs and a related constraint equation. By dealing with the constraint equation, we can derive infinite number of exact solutions for NLEEs. These solutions include the traveling wave solutions, non-traveling wave solutions, multi-soliton solutions, rational solutions, and other types of solutions. As applications, we obtained wide classes of exact solutions for the Boussinesq-Burgers equation by using the generalized simplest equation method.

  13. MHD flow of Burger's fluid over an off-centered rotating disk in a porous medium

    Science.gov (United States)

    Khan, Najeeb Alam; Khan, Sidra; Ullah, Saif

    2015-08-01

    In this study, off-centered stagnation flow of three dimensional Burger's fluid over an infinite rotating disk in a porous medium with a uniform magnetic field, which is applying normal to the disk, is investigated. A uniform suction/injection is applied through the surface of the porous disk. The structure has been modeled in the form of ordinary differential equations, which are reduced from partial differential equations by using the similarity transformation. Analytical solution is obtained by non-perturbation technique of homotopy analysis method (HAM). The influence of non-dimensional parameters on velocity profile is presented in graphical form and the numerical comparison is made with the viscous fluid as a special case.

  14. A generalized simplest equation method and its application to the Boussinesq-Burgers equation.

    Science.gov (United States)

    Sudao, Bilige; Wang, Xiaomin

    2015-01-01

    In this paper, a generalized simplest equation method is proposed to seek exact solutions of nonlinear evolution equations (NLEEs). In the method, we chose a solution expression with a variable coefficient and a variable coefficient ordinary differential auxiliary equation. This method can yield a Bäcklund transformation between NLEEs and a related constraint equation. By dealing with the constraint equation, we can derive infinite number of exact solutions for NLEEs. These solutions include the traveling wave solutions, non-traveling wave solutions, multi-soliton solutions, rational solutions, and other types of solutions. As applications, we obtained wide classes of exact solutions for the Boussinesq-Burgers equation by using the generalized simplest equation method.

  15. Structure of Shocks in Burgers Turbulence with Lévy Noise Initial Data

    Science.gov (United States)

    Abramson, Joshua

    2013-08-01

    We study the structure of the shocks for the inviscid Burgers equation in dimension 1 when the initial velocity is given by Lévy noise, or equivalently when the initial potential is a two-sided Lévy process ψ 0. When ψ 0 is abrupt in the sense of Vigon or has bounded variation with lim sup| h|↓0 h -2 ψ 0( h)=∞, we prove that the set of points with zero velocity is regenerative, and that in the latter case this set is equal to the set of Lagrangian regular points, which is non-empty. When ψ 0 is abrupt we show that the shock structure is discrete. When ψ 0 is eroded we show that there are no rarefaction intervals.

  16. Structure of shocks in Burgers turbulence with L\\'evy noise initial data

    CERN Document Server

    Abramson, Joshua

    2012-01-01

    We study the structure of the shocks for the inviscid Burgers equation in dimension 1 when the initial velocity is given by L\\'evy noise, or equivalently when the initial potential is a two-sided L\\'evy process $\\psi_0$. When $\\psi_0$ is abrupt in the sense of Vigon or has bounded variation with $\\lim_{|h| \\downarrow 0} h^{-2} \\psi_0(h) = \\infty$, we prove that the set of points with zero velocity is regenerative, and that in the latter case this set is equal to the set of Lagrangian regular points, which is non-empty. When $\\psi_0$ is abrupt we show that the shock structure is discrete. When $\\psi_0$ is eroded we show that there are no rarefaction intervals.

  17. Existence of solutions to Burgers equations in domains that can be transformed into rectangles

    Directory of Open Access Journals (Sweden)

    Yassine Benia

    2016-06-01

    Full Text Available This work is concerned with Burgers equation $\\partial _{t}u+u\\partial_x u-\\partial _x^2u=f$ (with Dirichlet boundary conditions in the non rectangular domain $\\Omega =\\{(t,x\\in R^2;\\ 0

  18. Maximum Rate of Growth of Enstrophy in Solutions of the Fractional Burgers Equation

    CERN Document Server

    Yun, Dongfang

    2016-01-01

    This investigation is a part of a research program aiming to characterize the extreme behavior possible in hydrodynamic models by probing the sharpness of estimates on the growth of certain fundamental quantities. We consider here the rate of growth of the classical and fractional enstrophy in the fractional Burgers equation in the subcritical, critical and supercritical regime. First, we obtain estimates on these rates of growth and then show that these estimates are sharp up to numerical prefactors. In particular, we conclude that the power-law dependence of the enstrophy rate of growth on the fractional dissipation exponent has the same global form in the subcritical, critical and parts of the supercritical regime. This is done by numerically solving suitably defined constrained maximization problems and then demonstrating that for different values of the fractional dissipation exponent the obtained maximizers saturate the upper bounds in the estimates as the enstrophy increases. In addition, nontrivial be...

  19. GENERALIZED FINITE SPECTRAL METHOD FOR 1D BURGERS AND KDV EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    ZHAN Jie-min; LI Yok-sheung

    2006-01-01

    A generalized finite spectral method is proposed. The method is of highorder accuracy. To attain high accuracy in time discretization, the fourth-order AdamsBashforth-Moulton predictor and corrector scheme was used. To avoid numerical oscillations caused by the dispersion term in the KdV equation, two numerical techniques were introduced to improve the numerical stability. The Legendre, Chebyshev and Hermite polynomials were used as the basis functions. The proposed numerical scheme is validated by applications to the Burgers equation (nonlinear convection- diffusion problem) and KdV equation(single solitary and 2-solitary wave problems), where analytical solutions are available for comparison. Numerical results agree very well with the corresponding analytical solutions in all cases.

  20. Diffusive approximation of a time-fractional Burgers equation in nonlinear acoustics

    CERN Document Server

    Lombard, Bruno

    2016-01-01

    A fractional time derivative is introduced into the Burgers equation to model losses of nonlinear waves. This term amounts to a time convolution product, which greatly penalizes the numerical modeling. A diffusive representation of the fractional derivative is adopted here, replacing this nonlocal operator by a continuum of memory variables that satisfy local-in-time ordinary differential equations. Then a quadrature formula yields a system of local partial differential equations, well-suited to numerical integration. The determination of the quadrature coefficients is crucial to ensure both the well-posedness of the system and the computational efficiency of the diffusive approximation. For this purpose, optimization with constraint is shown to be a very efficient strategy. Strang splitting is used to solve successively the hyperbolic part by a shock-capturing scheme, and the diffusive part exactly. Numerical experiments are proposed to assess the efficiency of the numerical modeling, and to illustrate the e...

  1. Forced convection analysis for generalized Burgers nanofluid flow over a stretching sheet

    Science.gov (United States)

    Khan, Masood; Khan, Waqar Azeem

    2015-10-01

    This article reports the two-dimensional forced convective flow of a generalized Burgers fluid over a linearly stretched sheet under the impacts of nano-sized material particles. Utilizing appropriate similarity transformations the coupled nonlinear partial differential equations are converted into a set of coupled nonlinear ordinary differential equations. The analytic results are carried out through the homotopy analysis method (HAM) to investigate the impact of various pertinent parameters for the velocity, temperature and concentration fields. The obtained results are presented in tabular form as well as graphically and discussed in detail. The presented results show that the rate of heat transfer at the wall and rate of nanoparticle volume fraction diminish with each increment of the thermophoresis parameter. While incremented values of the Brownian motion parameter lead to a quite opposite effect on the rates of heat transfer and nanoparticle volume fraction at the wall.

  2. Vector velocimeter

    DEFF Research Database (Denmark)

    2012-01-01

    for generation of a reference beam, a detector system comprising a first detector arrangement arranged in such a way that the signal beam and the reference beam are incident upon the first detector arrangement with the reference beam propagating at an angle relative to a signal beam, and wherein the first......The present invention relates to a compact, reliable and low-cost vector velocimeter for example for determining velocities of particles suspended in a gas or fluid flow, or for determining velocity, displacement, rotation, or vibration of a solid surface, the vector velocimeter comprising a laser...... assembly for emission of a measurement beam for illumination of an object in a measurement volume with coherent light whereby a signal beam emanating from the object in the measurement volume is formed in response to illumination of the object by the measurement beam, a reference beam generator...

  3. Use of quantitative microbial risk assessment when investigating foodborne illness outbreaks: the example of a monophasic Salmonella Typhimurium 4,5,12:i:- outbreak implicating beef burgers.

    Science.gov (United States)

    Guillier, Laurent; Danan, Corinne; Bergis, Hélène; Delignette-Muller, Marie-Laure; Granier, Sophie; Rudelle, Sylvie; Beaufort, Annie; Brisabois, Anne

    2013-09-16

    A major community outbreak of salmonellosis occurred in France in October 2010. Classical epidemiological investigations led to the identification of beef burgers as the cause of the outbreak and the presence of the emerging monophasic Salmonella Typhimurium 4,5,12:i:-. The objective of this study was to understand the events that led to this large outbreak, that is to say, what are the contributing factors associated with consumer exposure to Salmonella. To this end, intensive microbiological investigations on several beef burgers were conducted and a risk assessment model was built. The microbiological results confirm the presence of Salmonella in all analysed frozen burgers at high levels of contamination above 1000 MPN/g. These results in frozen burgers combined with a model of thermal destruction were used to estimate the dose ingested by the exposed persons. Most people that consumed cooked beef burgers were exposed from 1.6 to 3.1 log₁₀ (MPN). The number of sick people predicted with a dose-response relationship for Salmonella is consistent with the observed number of salmonellosis cases. The very high initial contamination level in frozen beef burgers is the primary cause of this large outbreak rather than bad cooking practices. Intensive investigations, modelling of the initial contamination and quantitative exposure and risk assessments are complementary to epidemiological investigation. They can be valuable elements for the assessment of missing information or the identification of the primary causes of outbreaks.

  4. Self-similar solutions for some nonlinear evolution equations: KdV, mKdV and Burgers equations

    Directory of Open Access Journals (Sweden)

    S.A. El-Wakil

    2016-02-01

    Full Text Available A method for solving three types of nonlinear evolution equations namely KdV, modified KdV and Burgers equations, with self-similar solutions is presented. The method employs ideas from symmetry reduction to space and time variables and similarity reductions for nonlinear evolution equations are performed. The obtained self-similar solutions of KdV and mKdV equations are related to Bessel and Airy functions whereas those of Burgers equation are related to the error and Hermite functions. These solutions appear as new types of solitary, shock and periodic waves. Also, the method can be applied to other nonlinear evolution equations in mathematical physics.

  5. Ion acoustic shock and periodic waves through Burgers equation in weakly and highly relativistic plasmas with nonextensivity

    Science.gov (United States)

    M, G. Hafez; N, C. Roy; M, R. Talukder; M Hossain, Ali

    2017-01-01

    A comparative study is carried out for the nonlinear propagation of ion acoustic shock waves both for the weakly and highly relativistic plasmas consisting of relativistic ions and q-distributed electrons and positions. The Burgers equation is derived to reveal the physical phenomena using the well known reductive perturbation technique. The integration of the Burgers equation is performed by the (G\\prime /G)-expansion method. The effects of positron concentration, ion–electron temperature ratio, electron–positron temperature ratio, ion viscosity coefficient, relativistic streaming factor and the strength of the electron and positron nonextensivity on the nonlinear propagation of ion acoustic shock and periodic waves are presented graphically and the relevant physical explanations are provided.

  6. Tetraplex PCR assay involving double gene-sites discriminates beef and buffalo in Malaysian meat curry and burger products.

    Science.gov (United States)

    Hossain, M A Motalib; Ali, Md Eaqub; Hamid, Sharifah Bee Abd; Hossain, S M Azad; Asing; Nizar, Nina Naquiah Ahmad; Uddin, Mohammad Nasir; Ali, Lokman; Asaduzzaman, Md; Akanda, Md Jahurul Haque

    2017-06-01

    Replacement of beef by buffalo and vice versa is frequent in global markets, but their authentication is challenging in processed foods due to the fragmentation of most biomarkers including DNA. The shortening of target sequences through use of two target sites might ameliorate assay reliability because it is highly unlikely that both targets will be lost during food processing. For the first time, we report a tetraplex polymerase chain reaction (PCR) assay targeting two different DNA regions in beef (106 and 120-bp) and buffalo (90 and 138-bp) mitochondrial genes to discriminate beef and buffalo in processed foods. All targets were stable under boiling, autoclaving and microwave cooking conditions. A survey in Malaysian markets revealed 71% beef curries contained buffalo but there was no buffalo in beef burgers. The assay detected down to 0.01ng DNA and 1% meat in admixed and burger products.

  7. Variable Separation Approach to Solve (2 + 1)-Dimensional Generalized Burgers System:Solitary Wave and Jacobi Periodic Wave Excitations

    Institute of Scientific and Technical Information of China (English)

    ZHENG Chun-Long

    2004-01-01

    By means of the standard truncated Painleve expansion and a variable separation approach, a general variable separation solution of the generalized Burgers system is derived. In addition to the usual localized coherent soliton excitations like dromions, lumps, rings, breathers, instantons, oscillating soliton excitations, peakons, foldons,and previously revealed chaotic and fractal localized solutions, some new types of excitations - compacton and Jacobi periodic wave solutions are obtained by introducing appropriate lower dimensional piecewise smooth functions and Jacobi elliptic functions.

  8. Solar vision Amsterdam. Citizens and businesses go for the sun; Zonvisie Amsterdam. Burgers en bedrijven gaan voor de zon

    Energy Technology Data Exchange (ETDEWEB)

    Stam, T.; Diependaal, F.; Van ' t Hull, C.

    2013-06-15

    In the Solar Vision it is explained how the Amsterdam municipality plans to enable its citizens and businesses to realize their own solar energy project. The Solar Vision is prepared based on input from residents, businesses and institutions [Dutch] In de zonvisie staat hoe de gemeente Amsterdam haar burgers en bedrijven in staat wil stellen om hun eigen zonne-energieproject te realiseren. De zonvisie is mede opgesteld op basis van input van bewoners, bedrijven en instellingen.

  9. Mediterranean Berries as Inhibitors of Lipid Oxidation in Porcine Burger Patties Subjected to Cooking and Chilled Storage

    Institute of Scientific and Technical Information of China (English)

    Rui Ganho; Mario Estvez; Mnica Armenteros; David Morcuende

    2013-01-01

    The efifciency of extracts from Arbutus unedo L. (AU), Crataegus monogyna L. (CM), Rosa canina L. (RC), and Rubus ulmifolius Schott. (RU) to inhibit lipid oxidation in raw, cooked and cooked and chilled (2°C/12 d) porcine burger patties, was investigated. The modiifcation of the fatty acid proifle during processing treatments (cooking and chilling), the quantitative measurements of thiobarbituric acid reactive substances (TBA-RS), and lipid-derived volatiles, were used as indicators of lipid oxidation. Polyunsaturated fatty acids (PUFA) gradually decreased during cooking and the subsequent storage of cooked burger patties with this decrease being signiifcantly greater (P<0.05) in control patties than in those with added berry extracts. In accordance, the control patties showed signiifcantly higher TBA-RS numbers and counts of lipid-derived volatiles in all treatments when compared to the berry-added counterparts (P<0.05). Results from the present work show, for the ifrst time, that extracts from A. unedo, C. monogyna, R. canina, and R. ulmifolius are promising antioxidants which could enhance the nutritional, safety and sensory properties of porcine burger patties.

  10. The Gassmann-Burgers Model to Simulate Seismic Waves at the Earth Crust And Mantle

    Science.gov (United States)

    Carcione, José M.; Poletto, Flavio; Farina, Biancamaria; Craglietto, Aronne

    2017-03-01

    The upper part of the crust shows generally brittle behaviour while deeper zones, including the mantle, may present ductile behaviour, depending on the pressure-temperature conditions; moreover, some parts are melted. Seismic waves can be used to detect these conditions on the basis of reflection and transmission events. Basically, from the elastic-plastic point of view the seismic properties (seismic velocity and density) depend on effective pressure and temperature. Confining and pore pressures have opposite effects on these properties, such that very small effective pressures (the presence of overpressured fluids) may substantially decrease the P- and S-wave velocities, mainly the latter, by opening of cracks and weakening of grain contacts. Similarly, high temperatures induce the same effect by partial melting. To model these effects, we consider a poro-viscoelastic model based on Gassmann equations and Burgers mechanical model to represent the properties of the rock frame and describe ductility in which deformation takes place by shear plastic flow. The Burgers elements allow us to model the effects of seismic attenuation, velocity dispersion and steady-state creep flow, respectively. The stiffness components of the brittle and ductile media depend on stress and temperature through the shear viscosity, which is obtained by the Arrhenius equation and the octahedral stress criterion. Effective pressure effects are taken into account in the dry-rock moduli using exponential functions whose parameters are obtained by fitting experimental data as a function of confining pressure. Since fluid effects are important, the density and bulk modulus of the saturating fluids (water and steam) are modeled using the equations provided by the NIST website, including supercritical behaviour. The theory allows us to obtain the phase velocity and quality factor as a function of depth and geological pressure and temperature as well as time frequency. We then obtain the PS and SH

  11. The Gassmann-Burgers Model to Simulate Seismic Waves at the Earth Crust And Mantle

    Science.gov (United States)

    Carcione, José M.; Poletto, Flavio; Farina, Biancamaria; Craglietto, Aronne

    2016-12-01

    The upper part of the crust shows generally brittle behaviour while deeper zones, including the mantle, may present ductile behaviour, depending on the pressure-temperature conditions; moreover, some parts are melted. Seismic waves can be used to detect these conditions on the basis of reflection and transmission events. Basically, from the elastic-plastic point of view the seismic properties (seismic velocity and density) depend on effective pressure and temperature. Confining and pore pressures have opposite effects on these properties, such that very small effective pressures (the presence of overpressured fluids) may substantially decrease the P- and S-wave velocities, mainly the latter, by opening of cracks and weakening of grain contacts. Similarly, high temperatures induce the same effect by partial melting. To model these effects, we consider a poro-viscoelastic model based on Gassmann equations and Burgers mechanical model to represent the properties of the rock frame and describe ductility in which deformation takes place by shear plastic flow. The Burgers elements allow us to model the effects of seismic attenuation, velocity dispersion and steady-state creep flow, respectively. The stiffness components of the brittle and ductile media depend on stress and temperature through the shear viscosity, which is obtained by the Arrhenius equation and the octahedral stress criterion. Effective pressure effects are taken into account in the dry-rock moduli using exponential functions whose parameters are obtained by fitting experimental data as a function of confining pressure. Since fluid effects are important, the density and bulk modulus of the saturating fluids (water and steam) are modeled using the equations provided by the NIST website, including supercritical behaviour. The theory allows us to obtain the phase velocity and quality factor as a function of depth and geological pressure and temperature as well as time frequency. We then obtain the PS and SH

  12. Vector nematicons

    CERN Document Server

    Horikis, Theodoros P

    2016-01-01

    Families of soliton pairs, namely vector solitons, are found within the context of a coupled nonlocal nonlinear Schrodinger system of equations, as appropriate for modeling beam propagation in nematic liquid crystals. In the focusing case, bright soliton pairs have been found to exist provided their amplitudes satisfy a specific condition. In our analytical approach, focused on the defocusing regime, we rely on a multiscale expansion methods, which reveals the existence of dark-dark and antidark-antidark solitons, obeying an effective Korteweg-de Vries equation, as well as dark-bright solitons, obeying an effective Mel'nikov system. These pairs are discriminated by the sign of a constant that links all physical parameters of the system to the amplitude of the stable continuous wave solutions, and, much like the focusing case, the solitons' amplitudes are linked leading to mutual guiding.

  13. Response of Acartia tonsa to Burgers' Vortex: Deconstructing Turbulence-Copepod Interactions

    Science.gov (United States)

    Young, D. L.; Webster, D. R.; Yen, J.

    2014-11-01

    In situ studies suggest that in many oceanic regimes, turbulence affects the vertical position of copepods primarily by changing their behavior, and only secondarily by altering their physical position. We test the hypothesis that fine-scale turbulence alters copepod behavior, presenting as alterations in directed movement and changes in swimming kinematics. To this end, we create two Burgers' vortices, specifying the rotation rate and axial strain rate to correspond to turbulent vortices with size scale equaling the inverse wavenumber of the median viscous dissipation rate (i.e. r = 8.1 η) for typical turbulent conditions in the coastal or near surface region (i.e., mean turbulent dissipation rates of 0.009 and 0.096 cm2/s3) . The vortex flow is quantified via tomo-PIV. Behavioral assays of Acartia tonsa are conducted, generating 3D trajectories for analysis of swimming kinematics and response to hydrodynamic cues. A. tonsa did not significantly respond to the vortex corresponding to dissipation rate of 0.009 cm2/s3, but drastically altered their swimming behavior in the presence of the 0.096 cm2/s3 vortex, including increased relative swim speed, angle of alignment with the vortex axis, net-to-gross displacement ratio, and escape acceleration, along with decreased turn frequency (relative to stagnant control conditions). Further, A. tonsa escape location is preferentially in the core of the stronger vortex, indicating that the hydrodynamic cue triggering the distinctive escape behavior is vorticity.

  14. New Solutions to Boussinesq-Burgers Equation%Boussinesq-Burgers方程新的精确解

    Institute of Scientific and Technical Information of China (English)

    史良马; 张世军; 朱仁义

    2013-01-01

    A new method of constructing exact solutions to nonlinear equation is introduced on the basis of the improved projective Riccati equations, and it is applied as an intermediate in expansion method to solve Boussinesq-Burgers equation. Many kinds of travelling wave solutions including Jacobi and Weierstrass elliptic function periodic are obtained. Besides many new results are obtained, too. With the help of Maple software, the proposed method can be also extended to construct more new exact solutions of some nonlinear evolution equations in mathematical physics.%基于改进的投影Riccati方程的解,提出一种新的构造非线性演化方程精确解的方法.通过这种方法,我们得导到了Boussinesq-Burgers方程各种类型的精确解,包括Jacobi和Weierstrass周期函数解.这种方法与数学软件Maple结合,简单易行,有助于探索其他非线性演化方程的精确解.

  15. Crossover to the Stochastic Burgers Equation for the WASEP with a Slow Bond

    Science.gov (United States)

    Franco, Tertuliano; Gonçalves, Patrícia; Simon, Marielle

    2016-09-01

    We consider the weakly asymmetric simple exclusion process in the presence of a slow bond and starting from the invariant state, namely the Bernoulli product measure of parameter {ρ in (0,1)}. The rate of passage of particles to the right (resp. left) is {1/2 + a/2n^{γ}} (resp. {1/2 - a/2n^{γ}}) except at the bond of vertices {{-1,0}} where the rate to the right (resp. left) is given by {α/2n^β + a/2n^{γ}} (resp. {α/2n^β-a/2n^{γ}}). Above, {α > 0}, {γ ≥ β ≥ 0}, {a≥ 0}. For {β Schwartz space if {γ > 1/2}, while for {γ = 1/2} it is an energy solution of the stochastic Burgers equation. For {γ ≥ β =1}, it is an Ornstein-Uhlenbeck process associated to the heat equation with Robin's boundary conditions. For {γ ≥ β > 1}, the limit density fluctuation field is an Ornstein-Uhlenbeck process associated to the heat equation with Neumann's boundary conditions.

  16. The E-assessment burger: Supporting the Before and After in E-Assessment Systems

    Directory of Open Access Journals (Sweden)

    Anne Adams

    2015-08-01

    Full Text Available This paper describes a threshold concept-driven e-assessment system that supports teachers in writing effective formative multiple-choice questions, creating quizzes tailored to students’ learning pathways. The system, which has been co-designed with teachers, acts as the ‘bun’ on either side of an ‘e-assessment burger’ pedagogically scaffolding quiz creation (the top of the bun, integrating the quiz within personalized learning trajectories (the burger and feeding the results back to the learners and teachers to guide the direction of future learning pathways (the bottom of the bun. The evaluation with 26 students in 3 subjects across two schools identified that supporting the before and after e-assessment empowers a shift in teachers’ encouragement for student ownership of assessment, guiding their learning pathways. Teachers also provide insights into how the system scaffolding and visualisations inspired changes to sequencing learning and teaching practices. In conclusion the changing role of assessment within a school ecosystem is debated.

  17. Exponentially slow traveling waves on a finite interval for Burgers' type equation

    Directory of Open Access Journals (Sweden)

    Pieter De Groen

    1998-11-01

    Full Text Available In this paper we study for small positive $epsilon$ the slow motion of the solution for evolution equations of Burgers' type with small diffusion, $$ u_t=epsilon u_{xx}+f(u,u_x,, quad u(x,0=u_0(x, quad u(pm 1,t=pm 1, $$ on the bounded spatial domain $[-1,1]$; $f$ is a smooth function satisfying $f(1>0, f(-1<0$ and $int_{-1}^{1}f(tdt=0$. The initial and boundary value problem~($star$ has a unique asymptotically stable equilibrium solution that attracts all solutions starting with continuous initial data $u_0$. On the infinite spatial domain ${mathbb R}$ the differential equation has slow speed traveling wave solutions generated by profiles that satisfy the boundary conditions of~($star$. As long as its zero stays inside the interval $[-1,1]$, such a traveling wave suitably describes the slow long term behaviour of the solution of ($star$ and its speed characterizes the local velocity of the slow motion with exponential precision. A solution that starts near a traveling wave moves in a small neighborhood of the traveling wave with exponentially slow velocity (measured as the speed of the unique zero during an exponentially long time interval $(0,T$. In this paper we give a unified treatment of the problem, using both Hilbert space and maximum principle methods, and we give rigorous proofs of convergence of the solution and of the asymptotic estimate of the velocity.

  18. Effects of pineapple byproduct and canola oil as fat replacers on physicochemical and sensory qualities of low-fat beef burger.

    Science.gov (United States)

    Selani, Miriam M; Shirado, Giovanna A N; Margiotta, Gregório B; Saldaña, Erick; Spada, Fernanda P; Piedade, Sonia M S; Contreras-Castillo, Carmen J; Canniatti-Brazaca, Solange G

    2016-02-01

    Pineapple byproduct and canola oil were evaluated as fat replacers on physicochemical and sensory characteristics of low-fat burgers. Five treatments were performed: conventional (CN, 20% fat) and four low-fat formulations (10% fat): control (CT), pineapple byproduct (PA), canola oil (CO), pineapple byproduct and canola oil (PC). Higher water and fat retention and lower cooking loss and diameter reduction were found in burgers with byproduct addition. In raw burgers, byproduct incorporation reduced L*, a*, and C* values, but these alterations were masked after cooking, leading to products similar to CN. Low-fat treatments were harder, chewier, and more cohesive than full-fat burgers. However, in Warner Bratzler shear measurements, PA and PC were as tender as CN. In QDA, no difference was found between CN and PC. Pineapple byproducts along with canola oil are promising fat replacers in beef burgers. In order to increase the feasibility of use of pineapple byproduct in the meat industry, alternative processes of byproduct preparation should be evaluated in future studies.

  19. Pineapple by-product and canola oil as partial fat replacers in low-fat beef burger: Effects on oxidative stability, cholesterol content and fatty acid profile.

    Science.gov (United States)

    Selani, Miriam M; Shirado, Giovanna A N; Margiotta, Gregório B; Rasera, Mariana L; Marabesi, Amanda C; Piedade, Sonia M S; Contreras-Castillo, Carmen J; Canniatti-Brazaca, Solange G

    2016-05-01

    The effect of freeze-dried pineapple by-product and canola oil as fat replacers on the oxidative stability, cholesterol content and fatty acid profile of low-fat beef burgers was evaluated. Five treatments were performed: conventional (CN, 20% fat) and four low-fat formulations (10% fat): control (CT), pineapple by-product (PA), canola oil (CO), and pineapple by-product and canola oil (PC). Low-fat cooked burgers showed a mean cholesterol content reduction of 9.15% compared to the CN. Canola oil addition improved the fatty acid profile of the burgers, with increase in the polyunsaturated/saturated fatty acids ratio and decrease in the n-6/n-3 ratio, in the atherogenic and thrombogenic indexes. The oxidative stability of the burgers was affected by the vegetable oil addition. However, at the end of the storage time (120 days), malonaldehyde values of CO and PC were lower than the threshold for the consumer's acceptance. Canola oil, in combination with pineapple by-product, can be considered promising fat replacers in the development of healthier burgers.

  20. Exact Solutions of the Time Fractional BBM-Burger Equation by Novel (G′/G-Expansion Method

    Directory of Open Access Journals (Sweden)

    Muhammad Shakeel

    2014-01-01

    Full Text Available The fractional derivatives are used in the sense modified Riemann-Liouville to obtain exact solutions for BBM-Burger equation of fractional order. This equation can be converted into an ordinary differential equation by using a persistent fractional complex transform and, as a result, hyperbolic function solutions, trigonometric function solutions, and rational solutions are attained. The performance of the method is reliable, useful, and gives newer general exact solutions with more free parameters than the existing methods. Numerical results coupled with the graphical representation completely reveal the trustworthiness of the method.

  1. A meshless method using radial basis functions for numerical solution of the two-dimensional KdV-Burgers equation

    Science.gov (United States)

    Zabihi, F.; Saffarian, M.

    2016-07-01

    The aim of this article is to obtain the numerical solution of the two-dimensional KdV-Burgers equation. We construct the solution by using a different approach, that is based on using collocation points. The solution is based on using the thin plate splines radial basis function, which builds an approximated solution with discretizing the time and the space to small steps. We use a predictor-corrector scheme to avoid solving the nonlinear system. The results of numerical experiments are compared with analytical solutions to confirm the accuracy and efficiency of the presented scheme.

  2. Travelling Wave Solutions for Time-delayed KdV-Burgers Equation%时滞KdV-Burgers方程的行波解

    Institute of Scientific and Technical Information of China (English)

    李二强; 李灵晓

    2012-01-01

    The time-delayed KdV-Burgers equation was derived by using the flux relaxation method. The travelling wave solutions of the time-delayed KdV-Burgers equation and the KdV-Burgers equation were obtained by the ( 1/G) -expansion method. According to these solutions, the qualitative analysis of the nonlinear ODEs reduced by using traveling wave variable of the time-delayed KdV-Burgers equation was given. When the delayed constant timed by the square of the traveling speed c equals the dissipative coefficient,there exist bell solitary wave and cnoidal wave solutions in the time-delayed KdV-Burgers equation, while the KdV-Burgers equation has no the two types solutions. The existence of time delaying affects the amplitude and the wave width of the solitary waves.%利用流量松弛方法导出了时滞KdV-Burgers方程,并利用(1/G)-展开法,求得时滞KdV-Burgers及KdV-Burgers方程的行波解.结合所求得的解,对时滞KdV-Burgers方程行波约化后所得的常微分方程组(ODEs)进行了定性分析.研究表明:当时间特征常数(r)与行波波速c的平方之积等于耗散系数α(即(r)c2=α)时,时滞KdV-Burgers方程出现了椭圆余弦波解和钟状孤波解,而KdV-Burgers方程没有此类解.另外,时滞的存在还影响到孤立波的振幅和波宽.

  3. Rotations with Rodrigues' Vector

    Science.gov (United States)

    Pina, E.

    2011-01-01

    The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears…

  4. An upwind super compact difference scheme for KdV-Burgers equation%一种求解 KdV-Burgers 方程的迎风超紧致差分格式

    Institute of Scientific and Technical Information of China (English)

    孙建安; 郭小霞; 贾伟

    2015-01-01

    In this paper , an upwind super compact difference scheme (USCD ) is proposed . The numerical characteristics of USCD are analyzed by using Fourier analysis , and compared with other upwind difference schemes and upwind compact difference schemes . According to analysis , it is found that USCD has better resolution and lower dissipation . Numerical solutions of the Burgers and KdV‐Burgers equations show that the USCD scheme has high‐order accuracy and is effective for long time evolution .%提出了一种迎风超紧致差分格式(USCD),利用Fourier分析方法对该格式的数值特性进行了分析,并与其他的迎风差分格式和迎风紧致差分格式做了对比。结果反映出USCD具有更好的分辨率和更低的耗散。通过对Burgers方程和KdV‐Burgers方程的数值模分析,进一步证实了USCD格式有更高的精度和对长时间演化问题的有效性。

  5. Numerical Solution to Generalized Burgers'-Fisher Equation Using Exp-Function Method Hybridized with Heuristic Computation

    Science.gov (United States)

    Malik, Suheel Abdullah; Qureshi, Ijaz Mansoor; Amir, Muhammad; Malik, Aqdas Naveed; Haq, Ihsanul

    2015-01-01

    In this paper, a new heuristic scheme for the approximate solution of the generalized Burgers'-Fisher equation is proposed. The scheme is based on the hybridization of Exp-function method with nature inspired algorithm. The given nonlinear partial differential equation (NPDE) through substitution is converted into a nonlinear ordinary differential equation (NODE). The travelling wave solution is approximated by the Exp-function method with unknown parameters. The unknown parameters are estimated by transforming the NODE into an equivalent global error minimization problem by using a fitness function. The popular genetic algorithm (GA) is used to solve the minimization problem, and to achieve the unknown parameters. The proposed scheme is successfully implemented to solve the generalized Burgers'-Fisher equation. The comparison of numerical results with the exact solutions, and the solutions obtained using some traditional methods, including adomian decomposition method (ADM), homotopy perturbation method (HPM), and optimal homotopy asymptotic method (OHAM), show that the suggested scheme is fairly accurate and viable for solving such problems. PMID:25811858

  6. Numerical solution to generalized Burgers'-Fisher equation using Exp-function method hybridized with heuristic computation.

    Directory of Open Access Journals (Sweden)

    Suheel Abdullah Malik

    Full Text Available In this paper, a new heuristic scheme for the approximate solution of the generalized Burgers'-Fisher equation is proposed. The scheme is based on the hybridization of Exp-function method with nature inspired algorithm. The given nonlinear partial differential equation (NPDE through substitution is converted into a nonlinear ordinary differential equation (NODE. The travelling wave solution is approximated by the Exp-function method with unknown parameters. The unknown parameters are estimated by transforming the NODE into an equivalent global error minimization problem by using a fitness function. The popular genetic algorithm (GA is used to solve the minimization problem, and to achieve the unknown parameters. The proposed scheme is successfully implemented to solve the generalized Burgers'-Fisher equation. The comparison of numerical results with the exact solutions, and the solutions obtained using some traditional methods, including adomian decomposition method (ADM, homotopy perturbation method (HPM, and optimal homotopy asymptotic method (OHAM, show that the suggested scheme is fairly accurate and viable for solving such problems.

  7. 改进的burgers岩石蠕变模型%Modified Burgers Rock Creep Model

    Institute of Scientific and Technical Information of China (English)

    李猛

    2013-01-01

    The experimental data analysis based on meas-ured characteristics of creep curves constructed to accelerate the performance of rock creep and creep stage attenuation character-istics of the nonlinear function into burgers creep constitutive e-quation, get a new nonlinear creep model, rock steady creep stage nonlinear gradual process and accelerate the rate of creep creep speed level can be adjusted to effectively simulate creep parameters. At low stress levels, the model can effectively por-tray the initial creep and stability of rock creep; when the stress level exceeds the long-term strength of the rock, to reflect ac-celerated creephrough the fitting of the obtained test data to de-termine material parameters on the creep model calculations and experimental results of the comparison indicates that the model can well describe the creep curve in the initial stages of decay and steady creep creep creep speed stage to prove correctness and rationality of the model.%基于实测的实验数据分析蠕变曲线的特征,构造出能够表现岩石衰减蠕变和加速蠕变阶段特征的非线性函数,并引入到burgers蠕变本构方程中,得到一个新的非线性蠕变模型,岩石稳定蠕变阶段的非线性渐变过程和加速蠕变阶段蠕变速率的快慢程度可通过调整蠕变参数进行有效地模拟。在较低应力水平时,模型能够有效地刻画岩石的初始蠕变和稳定蠕变;当应力水平超过岩石的长期强度时,能够反映加速蠕变特性。利用该模型对试验数据拟合的结果表明,对蠕变模型计算结果和试验结果的比较,表明该模型能够很好的描述蠕变曲线中的初始衰减蠕变阶段稳态蠕变阶段和加速蠕变阶段,证明了该模型的正确性和合理性。

  8. Concise vector analysis

    CERN Document Server

    Eliezer, C J; Maxwell, E A; Sneddon, I N

    1963-01-01

    Concise Vector Analysis is a five-chapter introductory account of the methods and techniques of vector analysis. These methods are indispensable tools in mathematics, physics, and engineering. The book is based on lectures given by the author in the University of Ceylon.The first two chapters deal with vector algebra. These chapters particularly present the addition, representation, and resolution of vectors. The next two chapters examine the various aspects and specificities of vector calculus. The last chapter looks into some standard applications of vector algebra and calculus.This book wil

  9. Light axial vector mesons

    CERN Document Server

    Chen, Kan; Liu, Xiang; Matsuki, Takayuki

    2015-01-01

    Inspired by the abundant experimental observation of axial vector states, we study whether the observed axial vector states can be categorized into the conventional axial vector meson family. In this paper we carry out analysis based on the mass spectra and two-body Okubo-Zweig-Iizuka-allowed decays. Besides testing the possible axial vector meson assignments, we also predict abundant information for their decays and the properties of some missing axial vector mesons, which are valuable to further experimental exploration of the observed and predicted axial vector mesons.

  10. Conditional Stability of Solitary-Wave Solutions for Generalized Compound KdV Equation and Generalized Compound KdV-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Guo; DONG Chun-Yan; FAN En-Gui

    2006-01-01

    In this paper, we discuss conditional stability of solitary-wave solutions in the sense of Liapunov for the generalized compound KdV equation and the generalized compound KdV-Burgers equations. Linear stability of the exact solitary-wave solutions is proved for the above two types of equations when the small disturbance of travellingwave form satisfies some special conditions.

  11. Heterocyclic aromatic amine content in chicken burgers and chicken nuggets sold in fast food restaurants and effects of green tea extract and microwave thawing on their formation

    Science.gov (United States)

    The aims of the current study were to investigate the presence of carcinogenic and mutagenic heterocyclic aromatic amines (HAAs) in chicken burgers (CBs) and chicken nuggets (CNs) purchased from fast food restaurants and the effects of green tea extract addition (GTE) to the covering material as wel...

  12. Analytical solutions for wall slip effects on magnetohydrodynamic oscillatory rotating plate and channel flows in porous media using a fractional Burgers viscoelastic model

    Science.gov (United States)

    Maqbool, Khadija; Anwar Bég, O.; Sohail, Ayesha; Idreesa, Shafaq

    2016-05-01

    The theoretical analysis of magnetohydrodynamic (MHD) incompressible flows of a Burgers fluid through a porous medium in a rotating frame of reference is presented. The constitutive model of a Burgers fluid is used based on a fractional calculus formulation. Hydrodynamic slip at the wall (plate) is incorporated and the fractional generalized Darcy model deployed to simulate porous medium drag force effects. Three different cases are considered: namely, the flow induced by a general periodic oscillation at a rigid plate, the periodic flow in a parallel plate channel and, finally, the Poiseuille flow. In all cases the plate(s) boundary(ies) are electrically non-conducting and a small magnetic Reynolds number is assumed, negating magnetic induction effects. The well-posed boundary value problems associated with each case are solved via Fourier transforms. Comparisons are made between the results derived with and without slip conditions. Four special cases are retrieved from the general fractional Burgers model, viz. Newtonian fluid, general Maxwell viscoelastic fluid, generalized Oldroyd-B fluid and the conventional Burgers viscoelastic model. Extensive interpretation of graphical plots is included. We study explicitly the influence of the wall slip on primary and secondary velocity evolution. The model is relevant to MHD rotating energy generators employing rheological working fluids.

  13. VectorBase

    Data.gov (United States)

    U.S. Department of Health & Human Services — VectorBase is a Bioinformatics Resource Center for invertebrate vectors. It is one of four Bioinformatics Resource Centers funded by NIAID to provide web-based...

  14. Sensory and Physicochemical Studies of Thermally Micronized Chickpea (Cicer arietinum) and Green Lentil (Lens culinaris) Flours as Binders in Low-Fat Beef Burgers.

    Science.gov (United States)

    Shariati-Ievari, Shiva; Ryland, Donna; Edel, Andrea; Nicholson, Tiffany; Suh, Miyoung; Aliani, Michel

    2016-05-01

    Pulses are known to be nutritious foods but are susceptible to oxidation due to the reaction of lipoxygenase (LOX) with linolenic and linoleic acids which can lead to off flavors caused by the formation of volatile organic compounds (VOCs). Infrared micronization at 130 and 150 °C was investigated as a heat treatment to determine its effect on LOX activity and VOCs of chickpea and green lentil flour. The pulse flours were added to low-fat beef burgers at 6% and measured for consumer acceptability and physicochemical properties. Micronization at 130 °C significantly decreased LOX activity for both flours. The lentil flour micronized at 150 °C showed a further significant decrease in LOX activity similar to that of the chickpea flour at 150 °C. The lowering of VOCs was accomplished more successfully with micronization at 130 °C for chickpea flour while micronization at 150 °C for the green lentil flour was more effective. Micronization minimally affected the characteristic fatty acid content in each flour but significantly increased omega-3 and n-6 fatty acids at 150 °C in burgers with lentil and chickpea flours, respectively. Burgers with green lentil flour micronized at 130 and 150 °C, and chickpea flour micronized at 150 °C were positively associated with acceptability. Micronization did not affect the shear force and cooking losses of the burgers made with both flours. Formulation of low-fat beef burgers containing 6% micronized gluten-free binder made from lentil and chickpea flour is possible based on favorable results for physicochemical properties and consumer acceptability.

  15. On Double Vector Bundles

    Institute of Scientific and Technical Information of China (English)

    Zhuo CHEN; Zhang Ju LIU; Yun He SHENG

    2014-01-01

    In this paper, we construct a category of short exact sequences of vector bundles and prove that it is equivalent to the category of double vector bundles. Moreover, operations on double vector bundles can be transferred to operations on the corresponding short exact sequences. In particular, we study the duality theory of double vector bundles in term of the corresponding short exact sequences. Examples including the jet bundle and the Atiyah algebroid are discussed.

  16. On Double Vector Bundles

    OpenAIRE

    Chen, Zhuo; Liu, Zhangju; Sheng, Yunhe

    2011-01-01

    In this paper, we construct a category of short exact sequences of vector bundles and prove that it is equivalent to the category of double vector bundles. Moreover, operations on double vector bundles can be transferred to operations on the corresponding short exact sequences. In particular, we study the duality theory of double vector bundles in term of the corresponding short exact sequences. Examples including the jet bundle and the Atiyah algebroid are discussed.

  17. Custodial vector model

    DEFF Research Database (Denmark)

    Becciolini, Diego; Franzosi, Diogo Buarque; Foadi, Roshan;

    2015-01-01

    We analyze the Large Hadron Collider (LHC) phenomenology of heavy vector resonances with a $SU(2)_L\\times SU(2)_R$ spectral global symmetry. This symmetry partially protects the electroweak S-parameter from large contributions of the vector resonances. The resulting custodial vector model spectrum...

  18. Symmetry Reductions of the Boussinesq-burgers Equation%Boussinesq-burgers方程的对称性约化

    Institute of Scientific and Technical Information of China (English)

    房春梅; 樊彩虹

    2014-01-01

    扩展齐次平衡法是求孤子方程的Backlund变换、对称性约化、精确解的一种简单有效的方法,该方法的思想是将高维的偏微分方程约化为低维的常微分方程。根据此方法获得了Boussinesq-burgers方程的新的对称性约化及相似解。%The extended homogeneous balance method is mainly used for finding the Backlund transforma-tion,symmetry reduction and exact solutions of nonlinear evolution equations .The idea of the method is to reduce the high dimensional partial differential to a low-dimensional ordinary differential equation .Based on this method , the new symmetry reduction and solution of the Boussinesq -burgers equation are ob-tained.

  19. Symmetry Reduction, Exact Solutions, and Conservation Laws of (2+1)-Dimensional Burgers Korteweg-de Vries Equation

    Institute of Scientific and Technical Information of China (English)

    DONG Zhong-Zhou; LIU Xi-Qiang; BAI Cheng-Lin

    2006-01-01

    Using the classical Lie method of infinitesimals, we first obtain the symmetry of the (2+1)-dimensional Burgers-Korteweg-de-Vries (3D-BKdV) equation. Then we reduce the 3D-BKdV equation using the symmetry and give some exact solutions of the 3D-BKdV equation. When using the direct method, we restrict a condition and get a relationship between the new solutions and the old ones. Given a solution of the 3D-BKdV equation, we can get a new one from the relationship. The relationship between the symmetry obtained by using the classical Lie method and that obtained by using the direct method is also mentioned. At last, we give the conservation laws of the 3D-BKdV equation.

  20. Vehicle Based Vector Sensor

    Science.gov (United States)

    2015-09-28

    300001 1 of 16 VEHICLE-BASED VECTOR SENSOR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...unmanned underwater vehicle that can function as an acoustic vector sensor . (2) Description of the Prior Art [0004] It is known that a propagating...mechanics. An acoustic vector sensor measures the particle motion via an accelerometer and combines Attorney Docket No. 300001 2 of 16 the

  1. Implicit Real Vector Automata

    Directory of Open Access Journals (Sweden)

    Jean-François Degbomont

    2010-10-01

    Full Text Available This paper addresses the symbolic representation of non-convex real polyhedra, i.e., sets of real vectors satisfying arbitrary Boolean combinations of linear constraints. We develop an original data structure for representing such sets, based on an implicit and concise encoding of a known structure, the Real Vector Automaton. The resulting formalism provides a canonical representation of polyhedra, is closed under Boolean operators, and admits an efficient decision procedure for testing the membership of a vector.

  2. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    Dias, Kealey

    vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...

  3. Vectors and their applications

    CERN Document Server

    Pettofrezzo, Anthony J

    2005-01-01

    Geared toward undergraduate students, this text illustrates the use of vectors as a mathematical tool in plane synthetic geometry, plane and spherical trigonometry, and analytic geometry of two- and three-dimensional space. Its rigorous development includes a complete treatment of the algebra of vectors in the first two chapters.Among the text's outstanding features are numbered definitions and theorems in the development of vector algebra, which appear in italics for easy reference. Most of the theorems include proofs, and coordinate position vectors receive an in-depth treatment. Key concept

  4. From nonlinear Burgers and Korteweg-de Vries soliton equations via Riccati to linear Rosen-Morse and free particle Schrödinger equations

    Science.gov (United States)

    Schuch, Dieter

    2015-06-01

    It is shown that a nonlinear reformulation of time-dependent and time-independent quantum mechanics in terms of Riccati equations not only provides additional information about the physical system, but also allows for formal comparison with other nonlinear theories. This is demonstrated for the nonlinear Burgers and Korteweg-de Vries equations with soliton solutions. As Riccati equations can be linearized to corresponding Schrödinger equations, this also applies to the Riccati equations that can be obtained by integrating the nonlinear soliton equations, resulting in a time-independent Schrödinger equation with Rosen-Morse potential and its supersymmetric partner. Because both soliton equations lead to the same Riccati equation, relations between the Burgers and Korteweg-de Vries equations can be established. Finally, a connection with the inverse scattering method is mentioned.

  5. Effect of Moringa (Moringa oleifera leaf powder and sweet basil (Ocimum basilicum leaf paste on sensory and nutritional qualities of beef and ham burgers – A preliminary study

    Directory of Open Access Journals (Sweden)

    Gabriel Teye

    2013-03-01

    Full Text Available Moringa leaf powder and sweet basil leaf paste are commonly used in local dishes in Ghana for purposes of flavour enhancement and nutrient supplements. This study was conducted to determine the effects of Moringa (Moringa oleifera leaf powder (MLP and Sweet basil (Ocimum basilicum leaf paste (SBLP on the sensory characteristics and nutritional compositions of beef and hamburgers. MLP and SBLP were incorporated at 0g (Control, T1, 2g, 4g and 6g/kg meat (T2, T3 and T4 respectively during the production of the burgers. The burgers were vacuum-packed and frozen for sensory and laboratory analyses. The M. oleifera leaf powder had significant (P0.01 the crude protein content but no significant effect on sensory characteristics of the products.

  6. The KdV-Burgers equation in a new continuum model with consideration of driverʼs forecast effect and numerical tests

    Science.gov (United States)

    Ge, Hong-Xia; Lai, Ling-Ling; Zheng, Peng-Jun; Cheng, Rong-Jun

    2013-12-01

    A new continuum traffic flow model is proposed based on an improved car-following model, which takes the driver's forecast effect into consideration. The backward travel problem is overcome by our model and the neutral stability condition of the new model is obtained through the linear stability analysis. Nonlinear analysis shows clearly that the density fluctuation in traffic flow leads to a variety of density waves and the Korteweg-de Vries-Burgers (KdV-Burgers) equation is derived to describe the traffic flow near the neutral stability line. The corresponding solution for traffic density wave is also derived. Finally, the numerical results show that our model can not only reproduce the evolution of small perturbation, but also improve the stability of traffic flow.

  7. The KdV–Burgers equation in a new continuum model with consideration of driver's forecast effect and numerical tests

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Hong-Xia [Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211 (China); Lai, Ling-Ling [Faculty of Science, Ningbo University, Ningbo 315211 (China); Zheng, Peng-Jun [Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211 (China); Cheng, Rong-Jun, E-mail: chengrongjun76@126.com [Ningbo Institute of Technology, Zhejiang University, Ningbo 315100 (China)

    2013-12-13

    A new continuum traffic flow model is proposed based on an improved car-following model, which takes the driver's forecast effect into consideration. The backward travel problem is overcome by our model and the neutral stability condition of the new model is obtained through the linear stability analysis. Nonlinear analysis shows clearly that the density fluctuation in traffic flow leads to a variety of density waves and the Korteweg–de Vries–Burgers (KdV–Burgers) equation is derived to describe the traffic flow near the neutral stability line. The corresponding solution for traffic density wave is also derived. Finally, the numerical results show that our model can not only reproduce the evolution of small perturbation, but also improve the stability of traffic flow.

  8. Application of the (′/)-expansion method for the Burgers, Burgers–Huxley and modified Burgers–KdV equations

    Indian Academy of Sciences (India)

    H Kheiri; M R Moghaddam; V Vafaei

    2011-06-01

    In this work, we present travelling wave solutions for the Burgers, Burgers–Huxley and modified Burgers–KdV equations. The (′/)-expansion method is used to determine travelling wave solutions of these sets of equations. The travelling wave solutions are expressed by the hyperbolic functions, the trigonometric functions and the rational functions. It is shown that the proposed method is direct, effective and can be used for many other nonlinear evolution equations in mathematical physics.

  9. 周期小波基下Burgers方程数值模拟%The Study of Periodic Wavelet Based Numerical Method Applied to Burgers' Equation

    Institute of Scientific and Technical Information of China (English)

    许伯强; 田立新

    2001-01-01

    This paper studies the numerical solution of the Galerkin projection onto a periodic wavelet basis of the Burgers partial differential equation with periodic boundary conditions.Based on the orthogonal transformation of both periodic spline wavelet within each scale and the symmetry of Burgers' equation,the nonlinerar Burgers' equation to ODEs is slmplified and the numerical solution is obtained.In phase space,an analysis is given to combinations of wavelets which represent ‘global’ functions.It is shown that the local models of the numerical solution based on periodic wavelets are more distinguishable than those of Fourier modes.This study provides a foundation for further work in which we use wavelet base to extract local models of nonlinear evolution equations.%研究周期边界条件下非线性Burgers 方程的周期小波基下Galerkin解.利用周期样条小波基的正交变换,结合Burgers方程所具有的对称性作线性变换,约化非线性Burgers方程为一组常微分方程组,得到该方程的Galerkin解,在相空间中进行分析,采用能表征全域特性的小波组合函数,数值分析表明周期小波基下Galerkin解与Fourier分析下的数值解比较更能反映方程的局部特征.本文的研究为非线性发展方程的局部复杂性研究提供了一个新的基础.

  10. 用同伦摄动法解Kdv-Burgers方程%Homotopy Perturbation Method and Approximate Solutions of Kdv-Burgers Equaition

    Institute of Scientific and Technical Information of China (English)

    李阳; 王佩臣

    2011-01-01

    利用行波变换将Kdv-Burgers方程化为常微分方程,并结合同伦摄动方法求它的二阶近似解.%Some discussion and gets to some conclusion are made on how to transform Kdv-Burgers equation into the ordinary differential equation with traveling wave transform method and homotopy perturbation method.And get the equations of second order approximate solutions.

  11. Several Kinds of Accurate Solutions on Generalized KdV-Burgers Equation%广义KdV-Burgers方程的几类精确解

    Institute of Scientific and Technical Information of China (English)

    胡建兰; 张汉林

    2000-01-01

    The general KdV-Burgers equation has been discussed in this paper. By using improved the method of HBM, we have gotten several kinds of accurate traveling wave solution.%讨论了广义KdV-Burgers方程. 通过使用改进的HBM方法,我们得到理几类精确的行波解.

  12. Traveling wave solutions of the (2 + 1-dimensional Zoomeron equation and the Burgers equations via the MSE method and the Exp-function method

    Directory of Open Access Journals (Sweden)

    Kamruzzaman Khan

    2014-03-01

    Full Text Available The modified simple equation (MSE method is promising for finding exact traveling wave solutions of nonlinear evolution equations (NLEEs in mathematical physics. In this letter, we investigate solutions of the (2 + 1-dimensional Zoomeron equation and the (2 + 1-dimensional Burgers equation by using the MSE method and the Exp-function method. The competence of the methods for constructing exact solutions has been established.

  13. Stokes' second problem for magnetohydrodynamics flow in a Burgers' fluid: the cases γ = λ²/4 and γ>λ²/4.

    Directory of Open Access Journals (Sweden)

    Ilyas Khan

    Full Text Available The present work is concerned with exact solutions of Stokes second problem for magnetohydrodynamics (MHD flow of a Burgers' fluid. The fluid over a flat plate is assumed to be electrically conducting in the presence of a uniform magnetic field applied in outward transverse direction to the flow. The equations governing the flow are modeled and then solved using the Laplace transform technique. The expressions of velocity field and tangential stress are developed when the relaxation time satisfies the condition γ =  λ²/4 or γ> λ²/4. The obtained closed form solutions are presented in the form of simple or multiple integrals in terms of Bessel functions and terms with only Bessel functions. The numerical integration is performed and the graphical results are displayed for the involved flow parameters. It is found that the velocity decreases whereas the shear stress increases when the Hartmann number is increased. The solutions corresponding to the Stokes' first problem for hydrodynamic Burgers' fluids are obtained as limiting cases of the present solutions. Similar solutions for Stokes' second problem of hydrodynamic Burgers' fluids and those for Newtonian and Oldroyd-B fluids can also be obtained as limiting cases of these solutions.

  14. Stokes' second problem for magnetohydrodynamics flow in a Burgers' fluid: the cases γ = λ²/4 and γ>λ²/4.

    Science.gov (United States)

    Khan, Ilyas; Ali, Farhad; Shafie, Sharidan

    2013-01-01

    The present work is concerned with exact solutions of Stokes second problem for magnetohydrodynamics (MHD) flow of a Burgers' fluid. The fluid over a flat plate is assumed to be electrically conducting in the presence of a uniform magnetic field applied in outward transverse direction to the flow. The equations governing the flow are modeled and then solved using the Laplace transform technique. The expressions of velocity field and tangential stress are developed when the relaxation time satisfies the condition γ =  λ²/4 or γ> λ²/4. The obtained closed form solutions are presented in the form of simple or multiple integrals in terms of Bessel functions and terms with only Bessel functions. The numerical integration is performed and the graphical results are displayed for the involved flow parameters. It is found that the velocity decreases whereas the shear stress increases when the Hartmann number is increased. The solutions corresponding to the Stokes' first problem for hydrodynamic Burgers' fluids are obtained as limiting cases of the present solutions. Similar solutions for Stokes' second problem of hydrodynamic Burgers' fluids and those for Newtonian and Oldroyd-B fluids can also be obtained as limiting cases of these solutions.

  15. Advancing vector biology research

    NARCIS (Netherlands)

    Kohl, Alain; Pondeville, Emilie; Schnettler, Esther; Crisanti, Andrea; Supparo, Clelia; Christophides, George K.; Kersey, Paul J.; Maslen, Gareth L.; Takken, Willem; Koenraadt, Constantianus J.M.; Oliva, Clelia F.; Busquets, Núria; Abad, F.X.; Failloux, Anna Bella; Levashina, Elena A.; Wilson, Anthony J.; Veronesi, Eva; Pichard, Maëlle; Arnaud Marsh, Sarah; Simard, Frédéric; Vernick, Kenneth D.

    2016-01-01

    Vector-borne pathogens impact public health, animal production, and animal welfare. Research on arthropod vectors such as mosquitoes, ticks, sandflies, and midges which transmit pathogens to humans and economically important animals is crucial for development of new control measures that target t

  16. Consumer's evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

    Science.gov (United States)

    Trindade, R. A.; Lima, A.; Andrade-Wartha, E. R.; Oliveira e Silva, A. M.; Mancini-Filho, J.; Villavicencio, A. L. C. H.

    2009-04-01

    The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 °C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA formulation obtained the highest score (6.73) and regarding the natural antioxidants, oregano received better acceptance (6.36). Irradiated samples formulated with oregano received a lower score, 6.03 in the first test and 5.06 in the second one, compared to the non-irradiated sample (6.36 and 5.79). In the second test (90 days), the sample formulated with BHT/BHA and which was irradiated received a higher score (6.59) when compared to the non-irradiated one (5.85). In both tests, the irradiated samples formulated with rosemary extract obtained a better score compared to the non-irradiated one, the scores being 5.00-3.82 and 5.00-3.76 in the first and second test, respectively. Our results allowed us to conclude that the natural antioxidants, rosemary and oregano extracts, present a good alternative for replacing synthetic additives in food industries, and that the irradiation process, in some cases, may help to enhance the sensory quality of food.

  17. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields....

  18. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    Dias, Kealey

    The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...

  19. Exploring Capabilities within ForTrilinos by Solving the 3D Burgers Equation

    Directory of Open Access Journals (Sweden)

    Karla Morris

    2012-01-01

    Full Text Available We present the first three-dimensional, partial differential equation solver to be built atop the recently released, open-source ForTrilinos package (http://trilinos.sandia.gov/packages/fortrilinos. ForTrilinos currently provides portable, object-oriented Fortran 2003 interfaces to the C++ packages Epetra, AztecOO and Pliris in the Trilinos library and framework [ACM Trans. Math. Softw.31(3 (2005, 397–423]. Epetra provides distributed matrix and vector storage and basic linear algebra calculations. Pliris provides direct solvers for dense linear systems. AztecOO provides iterative sparse linear solvers. We demonstrate how to build a parallel application that encapsulates the Message Passing Interface (MPI without requiring the user to make direct calls to MPI except for startup and shutdown. The presented example demonstrates the level of effort required to set up a high-order, finite-difference solution on a Cartesian grid. The example employs an abstract data type (ADT calculus [Sci. Program.16(4 (2008, 329–339] that empowers programmers to write serial code that lower-level abstractions resolve into distributed-memory, parallel implementations. The ADT calculus uses compilable Fortran constructs that resemble the mathematical formulation of the partial differential equation of interest.

  20. Simulation of seismic waves at the Earth crust (brittle-ductile transition based on the Burgers model

    Directory of Open Access Journals (Sweden)

    J. M. Carcione

    2014-06-01

    Full Text Available The Earth crust presents two dissimilar rheological behaviours depending on the in-situ stress-temperature conditions. The upper, cooler, part is brittle while deeper zones are ductile. Seismic waves may reveal the presence of the transition but a proper characterization is required. We first obtain a stress–strain relation including the effects of shear seismic attenuation and ductility due to shear deformations and plastic flow. The anelastic behaviour is based on the Burgers mechanical model to describe the effects of seismic attenuation and steady-state creep flow. The shear Lamé constant of the brittle and ductile media depends on the in-situ stress and temperature through the shear viscosity, which is obtained by the Arrhenius equation and the octahedral stress criterion. The P- and S-wave velocities decrease as depth and temperature increase due to the geothermal gradient, an effect which is more pronounced for shear waves. We then obtain the P-S and SH equations of motion recast in the velocity-stress formulation, including memory variables to avoid the computation of time convolutions. The equations correspond to isotropic anelastic and inhomogeneous media and are solved by a direct grid method based on the Runge–Kutta time stepping technique and the Fourier pseudospectral method. The algorithm is tested with success against known analytical solutions for different shear viscosities. A realistic example illustrates the computation of surface and reverse-VSP synthetic seismograms in the presence of an abrupt brittle-ductile transition.

  1. Spatial chaos in weakly dispersive and viscous media a nonperturbative theory of the driven KdV-Burgers equation

    CERN Document Server

    Malkov, M A

    1996-01-01

    The asymptotic travelling wave solution of the KdV-Burgers equation driven by the long scale periodic driver is constructed. The solution represents a shock-train in which the quasi-periodic sequence of dispersive shocks or soliton chains is interspersed by smoothly varying regions. It is shown that the periodic solution which has the spatial driver period undergoes period doublings as the governing parameter changes. Two types of chaotic behavior are considered. The first type is a weak chaos, where only a small chaotic deviation from the periodic solution occurs. The second type corresponds to the developed chaos where the solution ``ignores'' the driver period and represents a random sequence of uncorrelated shocks. In the case of weak chaos the shock coordinate being repeatedly mapped over the driver period moves on a chaotic attractor, while in the case of developed chaos it moves on a repellor. Both solutions depend on a parameter indicating the reference shock position in the shock-train. The structure...

  2. ON VECTOR NETWORK EQUILIBRIUM PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Guangya CHEN

    2005-01-01

    In this paper we define a concept of weak equilibrium for vector network equilibrium problems.We obtain sufficient conditions of weak equilibrium points and establish relation with vector network equilibrium problems and vector variational inequalities.

  3. Tagged Vector Contour (TVC)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas Tagged Vector Contour (TVC) dataset consists of digitized contours from the 7.5 minute topographic quadrangle maps. Coverage for the state is incomplete....

  4. GAP Land Cover - Vector

    Data.gov (United States)

    Minnesota Department of Natural Resources — This vector dataset is a detailed (1-acre minimum), hierarchically organized vegetation cover map produced by computer classification of combined two-season pairs of...

  5. Noncausal Bayesian Vector Autoregression

    DEFF Research Database (Denmark)

    Lanne, Markku; Luoto, Jani

    We propose a Bayesian inferential procedure for the noncausal vector autoregressive (VAR) model that is capable of capturing nonlinearities and incorporating effects of missing variables. In particular, we devise a fast and reliable posterior simulator that yields the predictive distribution...

  6. Vector Lattice Vortex Solitons

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-Dong; YE Fang-Wei; DONG Liang-Wei; LI Yong-Ping

    2005-01-01

    @@ Two-dimensional vector vortex solitons in harmonic optical lattices are investigated. The stability properties of such solitons are closely connected to the lattice depth Vo. For small Vo, vector vortex solitons with the total zero-angular momentum are more stable than those with the total nonzero-angular momentum, while for large Vo, this case is inversed. If Vo is large enough, both the types of such solitons are stable.

  7. Support vector machines applications

    CERN Document Server

    Guo, Guodong

    2014-01-01

    Support vector machines (SVM) have both a solid mathematical background and good performance in practical applications. This book focuses on the recent advances and applications of the SVM in different areas, such as image processing, medical practice, computer vision, pattern recognition, machine learning, applied statistics, business intelligence, and artificial intelligence. The aim of this book is to create a comprehensive source on support vector machine applications, especially some recent advances.

  8. The Vector Curvaton

    CERN Document Server

    Navarro, Andres A

    2013-01-01

    We analyze a massive vector field with a non-canonical kinetic term in the action, minimally coupled to gravity, where the mass and kinetic function of the vector field vary as functions of time during inflation. The vector field is introduced following the same idea of a scalar curvaton, which must not affect the inflationary dynamics since its energy density during inflation is negligible compared to the total energy density in the Universe. Using this hypothesis, the vector curvaton will be solely responsible for generating the primordial curvature perturbation \\zeta. We have found that the spectra of the vector field perturbations are scale-invariant in superhorizon scales due to the suitable choice of the time dependence of the kinetic function and the effective mass during inflation. The preferred direction, generated by the vector field, makes the spectrum of \\zeta depend on the wavevector, i.e. there exists statistical anisotropy in \\zeta. This is discussed principally in the case where the mass of th...

  9. Vector cross product in n-dimensional vector space

    OpenAIRE

    Tian, Xiu-Lao; Yang, Chao; Hu, Yang; Tian, Chao

    2013-01-01

    The definition of vector cross product (VCP) introduced by Eckmann only exists in thethree- and the seven- dimensional vector space. In this paper, according to the orthogonal completeness, magnitude of basis vector cross product and all kinds of combinations of basis vector $\\hat{e}_i$, the generalized definition of VCP in the odd n-dimensional vector space is given by introducing a cross term $X_{AB}$. In addition, the definition is validated by reducing the generalization definition to the...

  10. Extended Mixed Vector Equilibrium Problems

    Directory of Open Access Journals (Sweden)

    Mijanur Rahaman

    2014-01-01

    Full Text Available We study extended mixed vector equilibrium problems, namely, extended weak mixed vector equilibrium problem and extended strong mixed vector equilibrium problem in Hausdorff topological vector spaces. Using generalized KKM-Fan theorem (Ben-El-Mechaiekh et al.; 2005, some existence results for both problems are proved in noncompact domain.

  11. Bunyavirus-vector interactions.

    Science.gov (United States)

    Beaty, B J; Bishop, D H

    1988-06-01

    Recent advances in the genetics and molecular biology of bunyaviruses have been applied to understanding bunyavirus-vector interactions. Such approaches have revealed which virus gene and gene products are important in establishing infections in vectors and in transmission of viruses. However, much more information is required to understand the molecular mechanisms of persistent infections of vectors which are lifelong but apparently exert no untoward effect. In fact, it seems remarkable that LAC viral antigen can be detected in almost every cell in an ovarian follicle, yet no untoward effect on fecundity and no teratology is seen. Similarly the lifelong infection of the vector would seem to provide ample opportunity for bunyavirus evolution by genetic drift and, under the appropriate circumstances, by segment reassortment. The potential for bunyavirus evolution by segment reassortment in vectors certainly exists. For example the Group C viruses in a small forest in Brazil seem to constitute a gene pool, with the 6 viruses related alternately by HI/NT and CF reactions, which assay respectively M RNA and S RNA gene products (Casals and Whitman, 1960; Shope and Causey, 1962). Direct evidence for naturally occurring reassortant bunyaviruses has also been obtained. Oligonucleotide fingerprint analyses of field isolates of LAC virus and members of the Patois serogroup of bunyaviruses have demonstrated that reassortment does occur in nature (El Said et al., 1979; Klimas et al., 1981; Ushijima et al., 1981). Determination of the genotypic frequencies of viruses selected by the biological interactions of viruses and vectors after dual infection and segment reassortment is an important issue. Should a virus result that efficiently interacts with alternate vector species, the virus could be expressed in different circumstances with serious epidemiologic consequences. Dual infection of vectors with different viruses is not unlikely, because many bunyaviruses are sympatric in

  12. Vector Fields on Product Manifolds

    CERN Document Server

    Kurz, Stefan

    2011-01-01

    This short report establishes some basic properties of smooth vector fields on product manifolds. The main results are: (i) On a product manifold there always exists a direct sum decomposition into horizontal and vertical vector fields. (ii) Horizontal and vertical vector fields are naturally isomorphic to smooth families of vector fields defined on the factors. Vector fields are regarded as derivations of the algebra of smooth functions.

  13. Classification of Multiply Travelling Wave Solutions for Coupled Burgers, Combined KdV-Modified KdV, and Schrödinger-KdV Equations

    Directory of Open Access Journals (Sweden)

    A. R. Seadawy

    2015-01-01

    Full Text Available Some explicit travelling wave solutions to constructing exact solutions of nonlinear partial differential equations of mathematical physics are presented. By applying a theory of Frobenius decompositions and, more precisely, by using a transformation method to the coupled Burgers, combined Korteweg-de Vries- (KdV- modified KdV and Schrödinger-KdV equation is written as bilinear ordinary differential equations and two solutions to describing nonlinear interaction of travelling waves are generated. The properties of the multiple travelling wave solutions are shown by some figures. All solutions are stable and have applications in physics.

  14. A Class of Approximate Damped Oscillatory Solutions to Compound KdV-Burgers-Type Equation with Nonlinear Terms of Any Order: Preliminary Results

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2014-01-01

    Full Text Available This paper is focused on studying approximate damped oscillatory solutions of the compound KdV-Burgers-type equation with nonlinear terms of any order. By the theory and method of planar dynamical systems, existence conditions and number of bounded traveling wave solutions including damped oscillatory solutions are obtained. Utilizing the undetermined coefficients method, the approximate solutions of damped oscillatory solutions traveling to the left are presented. Error estimates of these approximate solutions are given by the thought of homogeneous principle. The results indicate that errors between implicit exact damped oscillatory solutions and approximate damped oscillatory solutions are infinitesimal decreasing in the exponential form.

  15. General projective Riccati equation method and exact solutions for generalized KdV-type and KdV-Burgers-type equations with nonlinear terms of any order

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yong E-mail: chenyong@dlut.edu.cn; Li Biao E-mail: libiao@dlut.edu.cn

    2004-03-01

    Applying the improved generalized method, which is a direct and unified algebraic method for constructing multiple travelling wave solutions of nonlinear partial differential equations and implemented in a computer algebraic system, we consider the KdV-type equations and KdV-Burgers-type equations with nonlinear terms of any order. As a result, we can not only successfully recover the previously known travelling wave solutions found by existing various tanh methods and other sophisticated methods, but also obtain some new formal solutions. The solutions obtained include kink-shaped solitons, bell-shaped solitons, singular solitons and periodic solutions.

  16. New exact solutions to MKDV-Burgers equation and (2 + 1)-dimensional dispersive long wave equation via extended Riccati equation method

    Energy Technology Data Exchange (ETDEWEB)

    Kong Cuicui [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)], E-mail: cuicuikong@yahoo.com.cn; Wang Dan; Song Lina; Zhang Hongqing [Department of Applied Mathematics, Dalian University of Technology, Dalian 116024 (China)

    2009-01-30

    In this paper, with the aid of symbolic computation and a general ansaetz, we presented a new extended rational expansion method to construct new rational formal exact solutions to nonlinear partial differential equations. In order to illustrate the effectiveness of this method, we apply it to the MKDV-Burgers equation and the (2 + 1)-dimensional dispersive long wave equation, then several new kinds of exact solutions are successfully obtained by using the new ansaetz. The method can also be applied to other nonlinear partial differential equations.

  17. Solitary wave and periodic wave solutions for Burgers, Fisher, Huxley and combined forms of these equations by the (′/)-expansion method

    Indian Academy of Sciences (India)

    Jalil Manafian; Mehrdad Lakestani

    2015-07-01

    An application of the (′/)-expansion method to search for exact solutions of nonlinear partial differential equations is analysed. This method is used for Burgers, Fisher, Huxley equations and combined forms of these equations. The (′/)-expansion method was used to construct periodic wave and solitary wave solutions of nonlinear evolution equations. This method is developed for searching exact travelling wave solutions of nonlinear partial differential equations. It is shown that the (′/)-expansion method, with the help of symbolic computation, provides a straightforward and powerful mathematical tool for solving nonlinear partial differential equations.

  18. Addendum to "Travelling waves for a non-local Korteweg-de Vries-Burgers equation" [J. Differential Equations 257 (3) (2014) 720-758

    Science.gov (United States)

    Cuesta, C. M.; Achleitner, F.

    2017-01-01

    We add a theorem to F. Achleitner, C.M. Cuesta and S. Hittmeir (2014) [1]. In that paper we studied travelling wave solutions of a Korteweg-de Vries-Burgers type equation with a non-local diffusion term. In particular, the proof of existence and uniqueness of these waves relies on the assumption that the exponentially decaying functions are the only bounded solutions of the linearised equation. In this addendum we prove this assumption and thus close the existence and uniqueness proof of travelling wave solutions.

  19. A numerical simulation and explicit solutions of KdV-Burgers' and Lax's seventh-order KdV equations

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, A.A. [Department of Mathematics, Faculty of Education (AL-Arish), Suez Canal University, AL-Arish 45111 (Egypt)]. E-mail: asoliman_99@yahoo.com

    2006-07-15

    By means of variational iteration method the solution of the Korteweg-de Vries Burgers (for short, KdVB) and a Lax's seventh-order KdV (for short, LsKdV) equations are exactly obtained and in compared with that found by means of Adomian decomposition method. The comparison demonstrate that the two obtained solutions are an excellent agreement. The numerical results calculated and show that this method, variational iteration method, can be readily implemented to this type of nonlinear equations and excellent accuracy can be also achieved. The results of variation iteration method confirm the correctness of those obtained by mean of Adomian decomposition method.

  20. The variational iteration method and the variational homotopy perturbation method for solving the KdV-Burgers equation and the Sharma-Tasso-Olver equation

    Energy Technology Data Exchange (ETDEWEB)

    Zayed, Elsayed M.E. [Dept. of Mathematics, Zagazig Univ. (Egypt); Abdel Rahman, Hanan M. [Dept. of Basic Sciences, Higher Technological Inst., Tenth of Ramadan City (Egypt)

    2010-01-15

    In this article, two powerful analytical methods called the variational iteration method (VIM) and the variational homotopy perturbation method (VHPM) are introduced to obtain the exact and the numerical solutions of the (2+1)-dimensional Korteweg-de Vries-Burgers (KdVB) equation and the (1+1)-dimensional Sharma-Tasso-Olver equation. The main objective of the present article is to propose alternative methods of solutions, which avoid linearization and physical unrealistic assumptions. The results show that these methods are very efficient, convenient and can be applied to a large class of nonlinear problems. (orig.)

  1. Boosting Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Elkin Eduardo García Díaz

    2006-11-01

    Full Text Available En este artículo, se presenta un algoritmo de clasificación binaria basado en Support Vector Machines (Máquinas de Vectores de Soporte que combinado apropiadamente con técnicas de Boosting consigue un mejor desempeño en cuanto a tiempo de entrenamiento y conserva características similares de generalización con un modelo de igual complejidad pero de representación más compacta./ In this paper we present an algorithm of binary classification based on Support Vector Machines. It is combined with a modified Boosting algorithm. It run faster than the original SVM algorithm with a similar generalization error and equal complexity model but it has more compact representation.

  2. Robustifying Vector Median Filter

    Directory of Open Access Journals (Sweden)

    Valentín Gregori

    2011-08-01

    Full Text Available This paper describes two methods for impulse noise reduction in colour images that outperform the vector median filter from the noise reduction capability point of view. Both methods work by determining first the vector median in a given filtering window. Then, the use of complimentary information from componentwise analysis allows to build robust outputs from more reliable components. The correlation among the colour channels is taken into account in the processing and, as a result, a more robust filter able to process colour images without introducing colour artifacts is obtained. Experimental results show that the images filtered with the proposed method contain less noisy pixels than those obtained through the vector median filter. Objective measures demonstrate the goodness of the achieved improvement.

  3. Matrix vector analysis

    CERN Document Server

    Eisenman, Richard L

    2005-01-01

    This outstanding text and reference applies matrix ideas to vector methods, using physical ideas to illustrate and motivate mathematical concepts but employing a mathematical continuity of development rather than a physical approach. The author, who taught at the U.S. Air Force Academy, dispenses with the artificial barrier between vectors and matrices--and more generally, between pure and applied mathematics.Motivated examples introduce each idea, with interpretations of physical, algebraic, and geometric contexts, in addition to generalizations to theorems that reflect the essential structur

  4. Free topological vector spaces

    OpenAIRE

    Gabriyelyan, Saak S.; Morris, Sidney A.

    2016-01-01

    We define and study the free topological vector space $\\mathbb{V}(X)$ over a Tychonoff space $X$. We prove that $\\mathbb{V}(X)$ is a $k_\\omega$-space if and only if $X$ is a $k_\\omega$-space. If $X$ is infinite, then $\\mathbb{V}(X)$ contains a closed vector subspace which is topologically isomorphic to $\\mathbb{V}(\\mathbb{N})$. It is proved that if $X$ is a $k$-space, then $\\mathbb{V}(X)$ is locally convex if and only if $X$ is discrete and countable. If $X$ is a metrizable space it is shown ...

  5. Duality in vector optimization

    CERN Document Server

    Bot, Radu Ioan

    2009-01-01

    This book presents fundamentals and comprehensive results regarding duality for scalar, vector and set-valued optimization problems in a general setting. After a preliminary chapter dedicated to convex analysis and minimality notions of sets with respect to partial orderings induced by convex cones a chapter on scalar conjugate duality follows. Then investigations on vector duality based on scalar conjugacy are made. Weak, strong and converse duality statements are delivered and connections to classical results from the literature are emphasized. One chapter is exclusively consecrated to the s

  6. Scalar-Vector Bootstrap

    CERN Document Server

    Rejon-Barrera, Fernando

    2015-01-01

    We work out all of the details required for implementation of the conformal bootstrap program applied to the four-point function of two scalars and two vectors in an abstract conformal field theory in arbitrary dimension. This includes a review of which tensor structures make appearances, a construction of the projectors onto the required mixed symmetry representations, and a computation of the conformal blocks for all possible operators which can be exchanged. These blocks are presented as differential operators acting upon the previously known scalar conformal blocks. Finally, we set up the bootstrap equations which implement crossing symmetry. Special attention is given to the case of conserved vectors, where several simplifications occur.

  7. Topological vector spaces

    CERN Document Server

    Narici, Lawrence

    2011-01-01

    BackgroundTopology Valuation Theory Algebra Linear Functionals Hyperplanes Measure Theory Normed SpacesCommutative Topological GroupsElementary ConsiderationsSeparation and Compactness Bases at 0 for Group Topologies Subgroups and Products Quotients S-Topologies Metrizability CompletenessCompleteness Function Groups Total BoundednessCompactness and Total Boundedness Uniform Continuity Extension of Uniformly Continuous Maps CompletionTopological Vector SpacesAbsorbent and Balanced Sets Convexity-AlgebraicBasic PropertiesConvexity-Topological Generating Vector Topologies A Non-Locally Convex Spa

  8. A SIMPLE VECTOR ANALYSIS METHOD FOR MARTENSITE CRYSTALLOGRAPHY%马氏体相变晶体学的简易矢量分析方法

    Institute of Scientific and Technical Information of China (English)

    顾新福; 张文征

    2011-01-01

    基于界面错配可以通过一组缺陷松弛的假设,发展了一种简易矢量分析法来计算界面包含一组缺陷的系统的相变晶体学.通过该方法可以方便地求解惯习面的取向.本文运用该方法求解了fcc/bcc系统中经典马氏体表象理论对应的相变晶体学,所有计算结果与文献报道完全一致.并根据矢量分析方法求解了满足上述假设条件惯习面取向的一般表达式.这一结果对系统地研究fcc/bcc中无理取向的惯习面提供了简便的分析工具.%The displacements of vectors in a habit plane (HP) are assumed to lie along a particular Burgers vector, so that the misfit in the interface can be fully accommodated by a set of dislocations with that Burgers vector. This assumption is consistent with many models and experimental observations. Based on this assumption, a simple method based on vector analysis has been developed.By applying this method to fcc/bcc system, the classical solutions from the phenomenal theory of martensite crystallography can be reproduced. In addition, a simple form of equation for general HP orientations satisfying the above assumption has also been derived. The present method provides a simple but general tool for analysis of irrational HP generated from either martensitic or diffusional transformations.

  9. Calculus with vectors

    CERN Document Server

    Treiman, Jay S

    2014-01-01

    Calculus with Vectors grew out of a strong need for a beginning calculus textbook for undergraduates who intend to pursue careers in STEM. fields. The approach introduces vector-valued functions from the start, emphasizing the connections between one-variable and multi-variable calculus. The text includes early vectors and early transcendentals and includes a rigorous but informal approach to vectors. Examples and focused applications are well presented along with an abundance of motivating exercises. All three-dimensional graphs have rotatable versions included as extra source materials and may be freely downloaded and manipulated with Maple Player; a free Maple Player App is available for the iPad on iTunes. The approaches taken to topics such as the derivation of the derivatives of sine and cosine, the approach to limits, and the use of "tables" of integration have been modified from the standards seen in other textbooks in order to maximize the ease with which students may comprehend the material. Additio...

  10. Synthetic Space Vector Modulation

    Science.gov (United States)

    2013-06-01

    Modulation RF Radio Frequency SVM Space Vector Modulation VCO Voltage Controlled Oscillator VSI Voltage Source Inverter xvi THIS PAGE...examining the literature, an NE566 voltage controlled oscillator ( VCO ) chip as seen in Figure 10 was used to design a circuit that produced the

  11. Vectors Point Toward Pisa

    Science.gov (United States)

    Dean, Richard A.

    1971-01-01

    The author shows that the set of all sequences in which each term is the sum of the two previous terms forms a vector space of dimension two. He uses this result to obtain the formula for the Fibonacci sequence and applies the same technique to other linear recursive relations. (MM)

  12. Vector-borne Infections

    Centers for Disease Control (CDC) Podcasts

    2011-04-18

    This podcast discusses emerging vector-borne pathogens, their role as prominent contributors to emerging infectious diseases, how they're spread, and the ineffectiveness of mosquito control methods.  Created: 4/18/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 4/27/2011.

  13. Estimation of vector velocity

    DEFF Research Database (Denmark)

    2000-01-01

    Using a pulsed ultrasound field, the two-dimensional velocity vector can be determined with the invention. The method uses a transversally modulated ultrasound field for probing the moving medium under investigation. A modified autocorrelation approach is used in the velocity estimation. The new...

  14. VECTOR BUNDLE, KILLING VECTOR FIELD AND PONTRYAGIN NUMBERS

    Institute of Scientific and Technical Information of China (English)

    周建伟

    1991-01-01

    Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E.

  15. Vector grammars and PN machines

    Institute of Scientific and Technical Information of China (English)

    蒋昌俊

    1996-01-01

    The concept of vector grammars under the string semantic is introduced.The dass of vector grammars is given,which is similar to the dass of Chomsky grammars.The regular vector grammar is divided further.The strong and weak relation between the vector grammar and scalar grammar is discussed,so the spectrum system graph of scalar and vector grammars is made.The equivalent relation between the regular vector grammar and Petri nets (also called PN machine) is pointed.The hybrid PN machine is introduced,and its language is proved equivalent to the language of the context-free vector grammar.So the perfect relation structure between vector grammars and PN machines is formed.

  16. On Generalized Vector Equilibrium Problems

    Institute of Scientific and Technical Information of China (English)

    An-hua Wan; Jun-yi Fu; Wei-hua Mao

    2006-01-01

    A new generalized vector equilibrium problem involving set-valued mappings and the proper quasi-concavity of set-valued mappings in topological vector spaces are introduced; its existence theorems and the convexity of the solution sets are established.

  17. Vector mesons in matter

    Indian Academy of Sciences (India)

    Gy Wolf

    2006-04-01

    One consequence of the chiral restoration is the mixing of parity partners. We look for a possible signature of the mixing of vector and axial vector mesons in heavy-ion collisions. We suggest an experimental method for its observation. The dynamical evolution of the heavy-ion collision is described by a transport equation of QMD-type evolving nucleons, * and resonances, ’s and $\\sum$ baryons, and furthermore, ’s, ’s ’s ’s ’s and kaons with their isospin degrees of freedom. The input cross-sections and resonance parameters of the model are fitted to the available nucleon–nucleon and pion–nucleon cross-sections.

  18. Vector fields in cosmology

    CERN Document Server

    Davydov, Evgeny

    2011-01-01

    Vector fields can arise in the cosmological context in different ways, and we discuss both abelian and nonabelian sector. In the abelian sector vector fields of the geometrical origin (from dimensional reduction and Einstein-Eddington modification of gravity) can provide a very non-trivial dynamics, which can be expressed in terms of the effective dilaton-scalar gravity with the specific potential. In the non-abelian sector we investigate the Yang-Mills SU(2) theory which admits isotropic and homogeneous configuration. Provided the non-linear dependence of the lagrangian on the invariant F*F(dual), one can obtain the inflationary regime with the exponential growth of the scale factor. The effective amplitudes of the 'electric' and 'magnetic' components behave like slowly varying scalars at this regime, what allows the consideration of some realistic models with non-linear terms in the Yang-Mills lagrangian.

  19. Helices and vector bundles

    CERN Document Server

    Rudakov, A N

    1990-01-01

    This volume is devoted to the use of helices as a method for studying exceptional vector bundles, an important and natural concept in algebraic geometry. The work arises out of a series of seminars organised in Moscow by A. N. Rudakov. The first article sets up the general machinery, and later ones explore its use in various contexts. As to be expected, the approach is concrete; the theory is considered for quadrics, ruled surfaces, K3 surfaces and P3(C).

  20. Student Preconceptions about Vector Kinematics.

    Science.gov (United States)

    Aguirre, Jose M.

    1988-01-01

    Examines preconceptions regarding several implicit vector characteristics that 15- to 17-year-old students possess just before taking their first physics course. Shows seven vector characteristics and three tasks for interviewing students. Presents the most common student preconceptions regarding each of the implicit vector characteristics. (YP)

  1. Decay Constants of Vector Mesons

    Institute of Scientific and Technical Information of China (English)

    LI Heng-Mei; WAN Shao-Long

    2008-01-01

    @@ The light vector mesons are studied within the framework of the Bethe-Salpeter equation with the vector-vectortype flat-bottom potential The Bethe-Salpeter wavefunctions and the decay constants of the vector mesons are obtained. All the obtained results, fρ, fφ, and fΚ* , are in agreement with the experimental values, respectively.

  2. Interpolation of Vector Measures

    Institute of Scientific and Technical Information of China (English)

    Ricardo del CAMPO; Antonio FERN(A)NDEZ; Fernando MAYORAL; Francisco NARANJO; Enrique A. S(A)NCHEZ-P(E)REZ

    2011-01-01

    Let (Ω, ∑) be a measurable space and m0: ∑→ X0 and m1: ∑ -→ X1 be positive vector measures with values in the Banach K(o)the function spaces X0 and X1. If 0 < α < 1, we define a X10-αXα1 and we analyze the space of integrable functions with respect to measure [m0, m1]α in order to prove suitable extensions of the classical Stein-Weiss formulas that hold for the complex interpolation of Lp-spaces.Since each p-convex order continuous K(o)the function space with weak order unit can be represented as a space of p-integrable functions with respect to a vector measure, we provide in this way a technique to obtain representations of the corresponding complex interpolation spaces. As applications, we provide a Riesz-Thorin theorem for spaces of p-integrable functions with respect to vector measures and a formula for representing the interpolation of the injective tensor product of such spaces.

  3. Cruising for Burgers

    DEFF Research Database (Denmark)

    Knakkergård, Martin

    2010-01-01

    Frank Zappas konceptalbum og filmmanuskript Uncle Meat fra 1969 kan på flere måder ses som en nøgle til hans kunst, hans samfundsopfattelse og hans livsforståelse. Allerede titlen synes at dække over et på samme tid humoristisk og aparte, ja, nærmest makabert dramatisk univers, og den lange progr...

  4. Burgers over kweekvlees

    NARCIS (Netherlands)

    Weele, van der C.N.; Driessen, C.P.G.

    2014-01-01

    Kweekvlees is vlees op basis van dierlijke cellen, gemaakt met behulp van weefselkweektechnieken. Het is een idee in ontwikkeling, waarvan tot nu toe alleen een ‘proof of principle’ is gepresenteerd.
    Kweekvlees roept meer op dan alleen positieve of negatieve reacties; het idee triggert discussie

  5. De burger als eunuch

    Directory of Open Access Journals (Sweden)

    N.C.F. van Sas

    2002-01-01

    Full Text Available 1800N.C.F. van Sas'1800. Blueprints for a society' argues the case for the primacy of culture in late 18th-century Dutch society. Drawing upon the work of a generation of dix-huitiémistes it presents an impressive and highly readable overview of the Dutch Enlightenment. Unfortunately, this cultural vantage-point also results in a rather one-sided, if not positively unhistorical reading of this period which — by all accounts so far — was highly charged with politics. In fact, an opportunity is missed to connect the Enlightened civil society of the 1760s and 1770s with the revolutionary developments of the 1780s and 1790s.

  6. Relativistic Rotating Vector Model

    CERN Document Server

    Lyutikov, Maxim

    2016-01-01

    The direction of polarization produced by a moving source rotates with the respect to the rest frame. We show that this effect, induced by pulsar rotation, leads to an important correction to polarization swings within the framework of rotating vector model (RVM); this effect has been missed by previous works. We construct relativistic RVM taking into account finite heights of the emission region that lead to aberration, time-of-travel effects and relativistic rotation of polarization. Polarizations swings at different frequencies can be used, within the assumption of the radius-to-frequency mapping, to infer emission radii and geometry of pulsars.

  7. Números, vectores y funciones

    OpenAIRE

    1992-01-01

    El texto Números, Vectores y Funciones que han elaborado los profesores Asociados Omar Evelio Ospina y Bernardo Acevedo, responden a esta necesidad con sobresalientes cualidades pedagógicas, entre las cuales se destacan el desarrollo detallado de los temas y la proliferación de ejercicios resueltos, lo cual genera un diálogo directo con el lector que puede así aprovechar totalmente su lectura. El material presentado es el fruto de un cuidadoso análisis de los autores, sobre las experiencias d...

  8. Vector potential photoelectron microscopy.

    Science.gov (United States)

    Browning, R

    2011-10-01

    A new class of electron microscope has been developed for the chemical microanalysis of a wide range of real world samples using photoelectron spectroscopy. Highly structured, three-dimensional samples, such as fiber mats and fracture surfaces can be imaged, as well as insulators and magnetic materials. The new microscope uses the vector potential field from a solenoid magnet as a spatial reference for imaging. A prototype instrument has demonstrated imaging of uncoated silk, magnetic steel wool, and micron-sized single strand tungsten wires.

  9. 变系数KdV-Burgers方程的精确解%Exact Solutions of KdV-Burgers Equations with Variable Coefficients

    Institute of Scientific and Technical Information of China (English)

    王岗伟; 张颖元

    2011-01-01

    Using the improved direct reduction method,we find the equivalence transformation of KdV-Burgers equations with variable eoeffidents,and obtain the correspondi.4g the relationshipbetween the solutions of KdV-Burgets equation and ones of the corresponding%利用修正的CK直接约化方法,把变系数KdV-Burgers方程约化为等价的常系数方程,得到了常系数和变系数KdV-Burgers方程的解之间的关系.另外,我们运用李群方法求得了常系数KdV-Burgers方程的解,从而获得了变系数KdV-Burgers方程的精确解.

  10. An explicit relaxation filtering framework based upon Perona-Malik anisotropic diffusion for shock capturing and subgrid scale modeling of Burgers turbulence

    CERN Document Server

    Maulik, Romit

    2016-01-01

    In this paper, we introduce a relaxation filtering closure approach to account for subgrid scale effects in explicitly filtered large eddy simulations using the concept of anisotropic diffusion. We utilize the Perona-Malik diffusion model and demonstrate its shock capturing ability and spectral performance for solving the Burgers turbulence problem, which is a simplified prototype for more realistic turbulent flows showing the same quadratic nonlinearity. Our numerical assessments present the behavior of various diffusivity functions in conjunction with a detailed sensitivity analysis with respect to the free modeling parameters. In comparison to direct numerical simulation (DNS) and under-resolved DNS results, we find that the proposed closure model is efficient in the prevention of energy accumulation at grid cut-off and is also adept at preventing any possible spurious numerical oscillations due to shock formation under the optimal parameter choices. In contrast to other relaxation filtering approaches, it...

  11. Extended vector-tensor theories

    Science.gov (United States)

    Kimura, Rampei; Naruko, Atsushi; Yoshida, Daisuke

    2017-01-01

    Recently, several extensions of massive vector theory in curved space-time have been proposed in many literatures. In this paper, we consider the most general vector-tensor theories that contain up to two derivatives with respect to metric and vector field. By imposing a degeneracy condition of the Lagrangian in the context of ADM decomposition of space-time to eliminate an unwanted mode, we construct a new class of massive vector theories where five degrees of freedom can propagate, corresponding to three for massive vector modes and two for massless tensor modes. We find that the generalized Proca and the beyond generalized Proca theories up to the quartic Lagrangian, which should be included in this formulation, are degenerate theories even in curved space-time. Finally, introducing new metric and vector field transformations, we investigate the properties of thus obtained theories under such transformations.

  12. Semitopological Vector Spaces and Hyperseminorms

    Directory of Open Access Journals (Sweden)

    Mark Burgin

    2013-11-01

    Full Text Available In this paper, we introduce and study semitopological vector spaces. The goal is to provide an efficient base for developing the theory of extrafunction spaces in an abstract setting of algebraic systems and topological spaces. Semitopological vector spaces are more general than conventional topological vector spaces, which proved to be very useful for solving many problems in functional analysis. To study semitopological vector spaces, hypermetrics and hyperpseudometrics are introduced and it is demonstrated that hyperseminorms, studied in previous works of the author, induce hyperpseudometrics, while hypernorms induce hypermetrics. Sufficient and necessary conditions for a hyperpseudometric (hypermetric to be induced by a hyperseminorm (hypernorm are found. We also show that semitopological vector spaces are closely related to systems of hyperseminorms. Then defining boundedness and continuity relative to associated systems of hyperseminorms, we study relations between relative boundedness and relative continuity for mappings of vector spaces with systems of hyperseminorms and systems of hypernorms.

  13. Safety considerations in vector development.

    Science.gov (United States)

    Kappes, J C; Wu, X

    2001-11-01

    The inadvertent production of replication competent retrovirus (RCR) constitutes the principal safety concern for the use of lentiviral vectors in human clinical protocols. Because of limitations in animal models to evaluate lentiviral vectors for their potential to recombine and induce disease, the vector design itself should ensure against the emergence of RCR in vivo. Issues related to RCR generation and one approach to dealing with this problem are discussed in this chapter. To assess the risk of generating RCR, a highly sensitive biological assay was developed to specifically detect vector recombination in transduced cells. Analysis of lentiviral vector stocks has shown that recombination occurs during reverse transcription in primary target cells. Rejoining of viral protein-coding sequences of the packaging construct and cis-acting sequences of the vector was demonstrated to generate env-minus recombinants (LTR-gag-pol-LTR). Mobilization of recombinant lentiviral genomes was also demonstrated but was dependent on pseudotyping of the vector core with an exogenous envelope protein. 5' sequence analysis has demonstrated that recombinants consist of U3, R, U5, and the psi packaging signal joined with an open gag coding region. Analysis of the 3' end has mapped the point of vector recombination to the poly(A) tract of the packaging construct's mRNA. The state-of-the-art third generation packaging construct and SIN vector also have been shown to generate env-minus proviral recombinants capable of mobilizing retroviral DNA when pseudotyped with an exogenous envelope protein. A new class of HIV-based vector (trans-vector) was recently developed that splits the gag-pol component of the packaging construct into two parts: one that expresses Gag/Gag-Pro and another that expresses Pol (RT and IN) fused with Vpr. Unlike other lentiviral vectors, the trans-vector has not been shown to form recombinants capable of DNA mobilization. These results indicate the trans-vector

  14. VLSI Processor For Vector Quantization

    Science.gov (United States)

    Tawel, Raoul

    1995-01-01

    Pixel intensities in each kernel compared simultaneously with all code vectors. Prototype high-performance, low-power, very-large-scale integrated (VLSI) circuit designed to perform compression of image data by vector-quantization method. Contains relatively simple analog computational cells operating on direct or buffered outputs of photodetectors grouped into blocks in imaging array, yielding vector-quantization code word for each such block in sequence. Scheme exploits parallel-processing nature of vector-quantization architecture, with consequent increase in speed.

  15. Entangled vector vortex beams

    Science.gov (United States)

    D'Ambrosio, Vincenzo; Carvacho, Gonzalo; Graffitti, Francesco; Vitelli, Chiara; Piccirillo, Bruno; Marrucci, Lorenzo; Sciarrino, Fabio

    2016-09-01

    Light beams having a vectorial field structure, or polarization, that varies over the transverse profile and a central optical singularity are called vector vortex (VV) beams and may exhibit specific properties such as focusing into "light needles" or rotation invariance. VV beams have already found applications in areas ranging from microscopy to metrology, optical trapping, nano-optics, and quantum communication. Individual photons in such beams exhibit a form of single-particle quantum entanglement between different degrees of freedom. On the other hand, the quantum states of two photons can be also entangled with each other. Here, we combine these two concepts and demonstrate the generation of quantum entanglement between two photons that are both in VV states: a form of entanglement between two complex vectorial fields. This result may lead to quantum-enhanced applications of VV beams as well as to quantum information protocols fully exploiting the vectorial features of light.

  16. Vectors in a Box

    CERN Document Server

    Buchin, Kevin; Moser, Robin A; Pálvölgyi, Dömötör

    2009-01-01

    For an integer d>=1, let tau(d) be the smallest integer with the following property: If v1,v2,...,vt is a sequence of t>=2 vectors in [-1,1]^d with v1+v2+...+vt in [-1,1]^d, then there is a subset S of {1,2,...,t} of indices, 2= d^{d/2-o(d)}. These results contribute to understanding the master equality polyhedron with multiple rows defined by Dash et al., which is a "universal" polyhedron encoding valid cutting planes for integer programs (this line of research was started by Gomory in the late 1960s). In particular, the upper bound on tau(d) implies a pseudo-polynomial running time for an algorithm of Dash et al. for integer programming with a fixed number of constraints. The algorithm consists in solving a linear program, and it provides an alternative to a 1981 dynamic programming algorithm of Papadimitriou.

  17. Resonance vector mode locking

    CERN Document Server

    Kolpakov, Stanislav A; Loika, Yuri; Tarasov, Nikita; Kalashnikov, Vladimir; Agrawal, Govind P

    2015-01-01

    A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow linewidth. However, further progress in linewidth narrowing seems to be limited by the complexity of the carrier-envelope phase control. Here for the first time we demonstrate experimentally and theoretically a new mechanism of resonance vector self-mode locking where tuning in-cavity birefringence leads to excitation of the longitudinal modes sidebands accompanied by the resonance phase locking of sidebands with the adjacent longitudinal modes. An additional resonance with acoustic phonons provides the repetition rate tunability and linewidth narrowing down to Hz range that drastically reduces the complexity of the carrier-envelope phase control and so will open the way to advance lasers in the context of applications in metrology, spectroscopy, microwave photonics, astronomy...

  18. Vector-Tensor and Vector-Vector Decay Amplitude Analysis of B0->phi K*0

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, R; Allen, M T; Allison, J; Altenburg, D D; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Asgeirsson, D J; Aston, D; Azzolini, V; Baak, M A; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Bechtle, P; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Best, D S; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P C; Blount, N L; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Bowerman, D A; Boyd, J T; Bozzi, C; Brandenburg, G; Brandt, T; Brau, J E; Briand, H; Brown, C M; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Bugg, W; Bukin, A D; Bula, R; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, E; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Chen, X R; Cheng, B; Cheng, C H; Chia, Y M; Cibinetto, G; Clark, P J; Clarke, C K; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Corwin, L A; Cossutti, F; Cottingham, W N; Couderc, F; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cunha, A; Curry, S; Côté, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; De Nardo, Gallieno; De Sangro, R; Del Amo-Sánchez, P; Del Buono, L; Del Re, D; Della Ricca, G; Denig, A G; Di Lodovico, F; Di Marco, E; Dingfelder, J C; Dittongo, S; Dong, L; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Ebert, M; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Egede, U; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fang, F; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, K E; Ford, W T; Forster, I J; Forti, F; Fortin, D; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gao, Y; Gary, J W; Gaspero, M; Gatto, C; Gaz, A; George, K A; Gill, M S; Giorgi, M A; Gladney, L; Glanzman, T; Godang, R; Golubev, V B; Gowdy, S J; Gradl, W; Graham, M T; Graugès-Pous, E; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Z J; Hadavand, H K; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jain, V; Jasper, H; Jawahery, A; Jessop, C P; Judd, D; Kadyk, J A; Kagan, H; Karyotakis, Yu; Kass, R; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Klose, V; Knecht, N S; Koch, H; Kolb, J A; Kolomensky, Yu G; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lange, D J; Lankford, A J; Latham, T E; Latour, E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lee, C L; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, S; Li, X; Lista, L; Liu, H; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; Long, O; Lopes-Pegna, D; Lopez-March, N; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Mclachlin, S E; Meadows, B T; Mellado, B; Menges, W; Merkel, J; Messner, R; Meyer, N T; Meyer, W T; Mihályi, A; Mir, L M; Mishra, K; Mohanty, G B; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morganti, M; Morganti, S; Morii, M; Muheim, F; Müller, D R; Nagel, M; Naisbit, M T; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nesom, G; Nicholson, H; Nikolich, M B; Nogowski, R; Nugent, I M; O'Grady, C P; Ocariz, J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A; Palombo, F; Pan, B; Pan, Y; Panduro, W; Paoloni, E; Paolucci, P; Pappagallo, M; Park, W; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Perazzo, A; Perl, M; Peruzzi, I M; Peters, K; Petersen, B A; Petrella, A; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Piredda, G; Playfer, S; Poireau, V; Polci, F; Pompili, A; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prencipe, E; Prepost, R; Pripstein, M; Pruvot, S; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rahmat, R; Rama, M; Ratcliff, B N; Raven, G; Regensburger, J J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roberts, D A; Robertson, A I; Robertson, S H; Robutti, E; Rodier, S; Roe, N A; Ronan, M T; Roney, J M; Rong, G; Roodman, A; Roos, L; Rosenberg, E I; Rotondo, M; Roudeau, P; Rubin, A E; Ruddick, W O; Röthel, W; Sacco, R; Saeed, M A; Safai-Tehrani, F; Saleem, M; Salnikov, A A; Salvatore, F; Sanders, D A; Santroni, A; Saremi, S; Satpathy, A; Schalk, T; Schenk, S; Schilling, C J; Schindler, R H; Schofield, K C; Schott, G; Schröder, T; Schröder, H; Schubert, J; Schubert, K R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Serrano, J; Sharma, V; Shen, B C; Sherwood, D J; Simard, M; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spitznagel, M; Spradlin, P; Steinke, M; Stelzer, J; Stocchi, A; Stoker, D P; Stroili, R; Strom, D; Strube, J; Stugu, B; Stängle, H; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; Suzuki, K; Swain, S K; Taras, P; Taylor, F; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Therin, G; Thiebaux, C; Thompson, J M; Tisserand, V; Todyshev, Y K; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Ulmer, K A; Uwer, U; Van Bakel, N; Vasseur, G; Vavra, J; Vazquez, A; Verderi, M; Viaud, F B; Vitale, L; Voci, C; Voena, C; Volk, A; Wagner, A P; Wagner, S R; Wagoner, D E; Waldi, R; Walker, D; Walsh, J J; Wang, K; Wang, P; Wang, W F; Wappler, F R; Watson, A T; Weaver, M; Weinstein, A J R; Wenzel, W A; Wilden, L; Williams, D C; Williams, J C; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Winklmeier, F; Wisniewski, W J; Wittgen, M; Wong, Q K; Wormser, G; Wren, A C; Wright, D H; Wright, D M; Wu, J; Wu, S L; Wulsin, H W; Xie, Y; Yamamoto, R K; Yarritu, A K; Ye, S; Yi, J I; Yi, K; Young, C C; Yu, Z; Yéche, C; Zain, S B; Zallo, A; Zeng, Q; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Ziegler, V; Zito, M; Çuhadar-Dönszelmann, T; al, et

    2007-01-01

    We perform an amplitude analysis of the decays B0->phi K^*_2(1430)0, phi K^*(892)0, and phi(K pi)^0_S-wave with a sample of about 384 million BBbar pairs recorded with the BABAR detector. The fractions of longitudinal polarization f_L of the vector-tensor and vector-vector decay modes are measured to be 0.853 +0.061-0.069 +-0.036 and 0.506 +-0.040 +-0.015, respectively. Overall, twelve parameters are measured for the vector-vector decay and seven parameters for the vector-tensor decay, including the branching fractions and parameters sensitive to CP-violation.

  19. Testing identifiablility of cointegrating vectors

    NARCIS (Netherlands)

    H.P. Boswijk

    1996-01-01

    This article analyzes the identification and normalization of cointegrating vectors. Normalizing a cointegrating relation with respect to one of the relevant variables is with loss of generality; and restrictions that are supposed to identify a vector may fail to do so for particular parameter value

  20. The Neural Support Vector Machine

    NARCIS (Netherlands)

    Wiering, Marco; van der Ree, Michiel; Embrechts, Mark; Stollenga, Marijn; Meijster, Arnold; Nolte, A; Schomaker, Lambertus

    2013-01-01

    This paper describes a new machine learning algorithm for regression and dimensionality reduction tasks. The Neural Support Vector Machine (NSVM) is a hybrid learning algorithm consisting of neural networks and support vector machines (SVMs). The output of the NSVM is given by SVMs that take a centr

  1. GPU Accelerated Vector Median Filter

    Science.gov (United States)

    Aras, Rifat; Shen, Yuzhong

    2011-01-01

    Noise reduction is an important step for most image processing tasks. For three channel color images, a widely used technique is vector median filter in which color values of pixels are treated as 3-component vectors. Vector median filters are computationally expensive; for a window size of n x n, each of the n(sup 2) vectors has to be compared with other n(sup 2) - 1 vectors in distances. General purpose computation on graphics processing units (GPUs) is the paradigm of utilizing high-performance many-core GPU architectures for computation tasks that are normally handled by CPUs. In this work. NVIDIA's Compute Unified Device Architecture (CUDA) paradigm is used to accelerate vector median filtering. which has to the best of our knowledge never been done before. The performance of GPU accelerated vector median filter is compared to that of the CPU and MPI-based versions for different image and window sizes, Initial findings of the study showed 100x improvement of performance of vector median filter implementation on GPUs over CPU implementations and further speed-up is expected after more extensive optimizations of the GPU algorithm .

  2. Vectors on the Basketball Court

    Science.gov (United States)

    Bergman, Daniel

    2010-01-01

    An Idea Bank published in the April/May 2009 issue of "The Science Teacher" describes an experiential physics lesson on vectors and vector addition (Brown 2009). Like its football predecessor, the basketball-based investigation presented in this Idea Bank addresses National Science Education Standards Content B, Physical Science, 9-12 (NRC 1996)…

  3. Simplified Representation of Vector Fields

    NARCIS (Netherlands)

    Telea, Alexandru; Wijk, Jarke J. van

    1999-01-01

    Vector field visualization remains a difficult task. Although many local and global visualization methods for vector fields such as flow data exist, they usually require extensive user experience on setting the visualization parameters in order to produce images communicating the desired insight. We

  4. Estimation of Motion Vector Fields

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    1993-01-01

    This paper presents an approach to the estimation of 2-D motion vector fields from time varying image sequences. We use a piecewise smooth model based on coupled vector/binary Markov random fields. We find the maximum a posteriori solution by simulated annealing. The algorithm generate sample...

  5. Emerging vector borne diseases – incidence through vectors

    Directory of Open Access Journals (Sweden)

    Sara eSavic

    2014-12-01

    Full Text Available Vector borne diseases use to be a major public health concern only in tropical and subtropical areas, but today they are an emerging threat for the continental and developed countries also. Nowdays, in intercontinetal countries, there is a struggle with emerging diseases which have found their way to appear through vectors. Vector borne zoonotic diseases occur when vectors, animal hosts, climate conditions, pathogens and susceptible human population exist at the same time, at the same place. Global climate change is predicted to lead to an increase in vector borne infectious diseases and disease outbreaks. It could affect the range and popultion of pathogens, host and vectors, transmission season, etc. Reliable surveilance for diseases that are most likely to emerge is required. Canine vector borne diseases represent a complex group of diseases including anaplasmosis, babesiosis, bartonellosis, borreliosis, dirofilariosis, erlichiosis, leishmaniosis. Some of these diseases cause serious clinical symptoms in dogs and some of them have a zoonotic potential with an effect to public health. It is expected from veterinarians in coordination with medical doctors to play a fudamental role at primeraly prevention and then treatment of vector borne diseases in dogs. The One Health concept has to be integrated into the struggle against emerging diseases.During a four year period, from 2009-2013, a total number of 551 dog samples were analysed for vector borne diseases (borreliosis, babesiosis, erlichiosis, anaplasmosis, dirofilariosis and leishmaniasis in routine laboratory work. The analysis were done by serological tests – ELISA for borreliosis, dirofilariosis and leishmaniasis, modified Knott test for dirofilariosis and blood smear for babesiosis, erlichiosis and anaplasmosis. This number of samples represented 75% of total number of samples that were sent for analysis for different diseases in dogs. Annually, on avarege more then half of the samples

  6. 变系数广义KdV—Burgers方程的精确类孤子解%Exact Soliton Like Solutions of the Variable Coefficient Generalized KdV-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    包永梅; 高娃

    2011-01-01

    By using a transformation, the variable coefficient generalized KdV-Burgers equation is reduced to nonlinear ordinary differential equation (NLODE). Several exact soliton-like solutions for the variable coefficient generalized KdV-Burgers equation are obtained through use of the corresponding reduced NLODE. Form this example we can see that this method can be applied to solve a large number of nonlinear evolution equations.%利用一种函数变换将变系数广义KdV—Burgers方程约化为非线性常微分方程(NLODE).并由此NLODE出发获得变系数广义KdV—Burgers方程的若干精确类孤子解。由此可见,用这种方法还可以求解一大类变系数非线性演化方程。

  7. EXTENSION TO THE DIRECT METHODS AND APPLICATIONS TO THE GENERALIZED BURGERS EQUATION%直接法的推广与广义Burgers方程的条件对称约化

    Institute of Scientific and Technical Information of China (English)

    张全举; 冯芙叶

    2002-01-01

    A generalization of the direct method of Clarkson and Kruskal for finding similarity reductions of partial differential equations with arbitrary functions is found and discussed for the generalized Burgers equation. The corresponding reductions and the exact solutions due to the methods of the ordinary differential equations are then given by the methods. The results given here answer partially an open problem proposed by Clarkson, that is how to develop the direct method to seek symmetry reductions of nonlinear PDEs with arbitrary functions.

  8. Chikungunya Virus–Vector Interactions

    Directory of Open Access Journals (Sweden)

    Lark L. Coffey

    2014-11-01

    Full Text Available Chikungunya virus (CHIKV is a mosquito-borne alphavirus that causes chikungunya fever, a severe, debilitating disease that often produces chronic arthralgia. Since 2004, CHIKV has emerged in Africa, Indian Ocean islands, Asia, Europe, and the Americas, causing millions of human infections. Central to understanding CHIKV emergence is knowledge of the natural ecology of transmission and vector infection dynamics. This review presents current understanding of CHIKV infection dynamics in mosquito vectors and its relationship to human disease emergence. The following topics are reviewed: CHIKV infection and vector life history traits including transmission cycles, genetic origins, distribution, emergence and spread, dispersal, vector competence, vector immunity and microbial interactions, and co-infection by CHIKV and other arboviruses. The genetics of vector susceptibility and host range changes, population heterogeneity and selection for the fittest viral genomes, dual host cycling and its impact on CHIKV adaptation, viral bottlenecks and intrahost diversity, and adaptive constraints on CHIKV evolution are also discussed. The potential for CHIKV re-emergence and expansion into new areas and prospects for prevention via vector control are also briefly reviewed.

  9. Stable piecewise polynomial vector fields

    Directory of Open Access Journals (Sweden)

    Claudio Pessoa

    2012-09-01

    Full Text Available Let $N={y>0}$ and $S={y<0}$ be the semi-planes of $mathbb{R}^2$ having as common boundary the line $D={y=0}$. Let $X$ and $Y$ be polynomial vector fields defined in $N$ and $S$, respectively, leading to a discontinuous piecewise polynomial vector field $Z=(X,Y$. This work pursues the stability and the transition analysis of solutions of $Z$ between $N$ and $S$, started by Filippov (1988 and Kozlova (1984 and reformulated by Sotomayor-Teixeira (1995 in terms of the regularization method. This method consists in analyzing a one parameter family of continuous vector fields $Z_{epsilon}$, defined by averaging $X$ and $Y$. This family approaches $Z$ when the parameter goes to zero. The results of Sotomayor-Teixeira and Sotomayor-Machado (2002 providing conditions on $(X,Y$ for the regularized vector fields to be structurally stable on planar compact connected regions are extended to discontinuous piecewise polynomial vector fields on $mathbb{R}^2$. Pertinent genericity results for vector fields satisfying the above stability conditions are also extended to the present case. A procedure for the study of discontinuous piecewise vector fields at infinity through a compactification is proposed here.

  10. 同伦摄动法在求解分数阶KdV-Burgers方程中的应用%Application of Homotopy Perturbation Method in Solving Fractional KdV-Burgers Equation

    Institute of Scientific and Technical Information of China (English)

    陈红菊

    2013-01-01

    In this paper, the homotopy perturbation method (HPM) is applied to solve a time-fractional KdV-Burgers equation. The second order approximate solutions are obtained very conveniently. At the same time, the numerical solutions of the KdV-Burgers differential equation under some values of the fractional order are obtained with Maple software. The results show that HPM method has high accuracy, little quantity of calculation for the solutions of the nonlinear differential equations. It is effective for the time-fractional KdV-Burgers differential equation.%  本文利用同伦摄动法(HPM)求解关于时间分数阶KdV-Burgers方程,得到它的二阶近似解。利用Maple软件编程计算给出了不同分数阶值下的二阶数值解。结果表明:HPM方法求解微分方程近似解时具有精确度高、计算量小的优点,因而HPM方法对分数阶KdV-Burgers方程是有效的。

  11. Vector fields on nonorientable surfaces

    Directory of Open Access Journals (Sweden)

    Dorin Ghisa

    2003-01-01

    Full Text Available A one-to-one correspondence is established between the germs of functions and tangent vectors on a NOS X and the bi-germs of functions, respectively, elementary fields of tangent vectors (EFTV on the orientable double cover of X. Some representation theorems for the algebra of germs of functions, the tangent space at an arbitrary point of X, and the space of vector fields on X are proved by using a symmetrisation process. An example related to the normal derivative on the border of the Möbius strip supports the nontriviality of the concepts introduced in this paper.

  12. Vector boson scattering at CLIC

    Energy Technology Data Exchange (ETDEWEB)

    Kilian, Wolfgang; Fleper, Christian [Department Physik, Universitaet Siegen, 57068 Siegen (Germany); Reuter, Juergen [DESY Theory Group, 22603 Hamburg (Germany); Sekulla, Marco [Institut fuer Theoretische Physik, Karlsruher Institut fuer Technologie, 76131 Karlsruhe (Germany)

    2016-07-01

    Linear colliders operating in a range of multiple TeV are able to investigate the details of vector boson scattering and electroweak symmetry breaking. We calculate cross sections with the Monte Carlo generator WHIZARD for vector boson scattering processes at the future linear e{sup +} e{sup -} collider CLIC. By finding suitable cuts, the vector boson scattering signal processes are isolated from the background. Finally, we are able to determine exclusion sensitivities on the non-Standard Model parameters of the relevant dimension eight operators.

  13. Vector control of induction machines

    CERN Document Server

    Robyns, Benoit

    2012-01-01

    After a brief introduction to the main law of physics and fundamental concepts inherent in electromechanical conversion, ""Vector Control of Induction Machines"" introduces the standard mathematical models for induction machines - whichever rotor technology is used - as well as several squirrel-cage induction machine vector-control strategies. The use of causal ordering graphs allows systematization of the design stage, as well as standardization of the structure of control devices. ""Vector Control of Induction Machines"" suggests a unique approach aimed at reducing parameter sensitivity for

  14. On the Witt vector Frobenius

    DEFF Research Database (Denmark)

    Davis, Christopher James; Kedlaya, Kiran

    2014-01-01

    We study the kernel and cokernel of the Frobenius map on the p-typical Witt vectors of a commutative ring, not necessarily of characteristic p. We give many equivalent conditions to surjectivity of the Frobenius map on both finite and infinite length Witt vectors. In particular, surjectivity...... on finite Witt vectors turns out to be stable under certain integral extensions; this provides a clean formulation of a strong generalization of Faltings’s almost purity theorem from p-adic Hodge theory, incorporating recent improvements by Kedlaya–Liu and by Scholze....

  15. All optical vector magnetometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I research project will investigate a novel method of operating an atomic magnetometer to simultaneously measure total magnetic fields and vector magnetic...

  16. Introduction to matrices and vectors

    CERN Document Server

    Schwartz, Jacob T

    2001-01-01

    In this concise undergraduate text, the first three chapters present the basics of matrices - in later chapters the author shows how to use vectors and matrices to solve systems of linear equations. 1961 edition.

  17. GRE Enzymes for Vector Analysis

    Data.gov (United States)

    U.S. Environmental Protection Agency — Microbial enzyme data that were collected during the 2004-2006 EMAP-GRE program. These data were then used by Moorhead et al (2016) in their ecoenzyme vector...

  18. Acoustic vector sensor signal processing

    Institute of Scientific and Technical Information of China (English)

    SUN Guiqing; LI Qihu; ZHANG Bin

    2006-01-01

    Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on.

  19. Transcriptional Silencing of Retroviral Vectors

    DEFF Research Database (Denmark)

    Lund, Anders Henrik; Duch, M.; Pedersen, F.S.

    1996-01-01

    . Extinction of long-term vector expression has been observed after implantation of transduced hematopoietic cells as well as fibroblasts, myoblasts and hepatocytes. Here we review the influence of vector structure, integration site and cell type on transcriptional silencing. While down-regulation of proviral...... transcription is known from a number of cellular and animal models, major insight has been gained from studies in the germ line and embryonal cells of the mouse. Key elements for the transfer and expression of retroviral vectors, such as the viral transcriptional enhancer and the binding site for the t......RNA primer for reverse transcription may have a major influence on transcriptional silencing. Alterations of these elements of the vector backbone as well as the use of internal promoter elements from housekeeping genes may contribute to reduce transcriptional silencing. The use of cell culture and animal...

  20. Unsupervised learning of binary vectors

    Science.gov (United States)

    Copelli Lopes da Silva, Mauro

    In this thesis, unsupervised learning of binary vectors from data is studied using methods from Statistical Mechanics of disordered systems. In the model, data vectors are distributed according to a single symmetry-breaking direction. The aim of unsupervised learning is to provide a good approximation to this direction. The difference with respect to previous studies is the knowledge that this preferential direction has binary components. It is shown that sampling from the posterior distribution (Gibbs learning) leads, for general smooth distributions, to an exponentially fast approach to perfect learning in the asymptotic limit of large number of examples. If the distribution is non-smooth, then first order phase transitions to perfect learning are expected. In the limit of poor performance, a second order phase transition ("retarded learning") is predicted to occur if the data distribution is not biased. Using concepts from Bayesian inference, the center of mass of the Gibbs ensemble is shown to have maximal average (Bayes-optimal) performance. This upper bound for continuous vectors is extended to a discrete space, resulting in the clipped center of mass of the Gibbs ensemble having maximal average performance among the binary vectors. To calculate the performance of this best binary vector, the geometric properties of the center of mass of binary vectors are studied. The surprising result is found that the center of mass of infinite binary vectors which obey some simple constraints, is again a binary vector. When disorder is taken into account in the calculation, however, a vector with continuous components is obtained. The performance of the best binary vector is calculated and shown to always lie above that of Gibbs learning and below the Bayes-optimal performance. Making use of a variational approach under the replica symmetric ansatz, an optimal potential is constructed in the limits of zero temperature and mutual overlap 1. Minimization of this potential

  1. Disease Vector Ecology Profile: Colombia

    Science.gov (United States)

    1998-12-01

    Cordillera Oriental. Studies in Norte de Santander Department in 1985 indicate 15.6% of the houses were infested with the vector, 30% of the...population studied had positive serologies, and 9% displayed abnormal heart function. Trypanosoma cruzi is found in animals and extradomiciliary vectors...drainage toward Lopez, the river slows and Simulium exiguum are less abundant than they are near San Antonio. From 1990-1995, Ivermectin (antihelminthic

  2. Handling S/MAR vectors.

    Science.gov (United States)

    Hagedorn, Claudia; Baiker, Armin; Postberg, Jan; Ehrhardt, Anja; Lipps, Hans J

    2012-06-01

    Nonviral episomal vectors represent attractive alternatives to currently used virus-based expression systems. In the late 1990s, it was shown that a plasmid containing an expression cassette linked to a scaffold/matrix attached region (S/MAR) replicates as a low copy number episome in all cell lines tested, as well as primary cells, and can be used for the genetic modification of higher animals. Once established in the cell, the S/MAR vector replicates early during S-phase and, in the absence of selection, is stably retained in the cells for an unlimited period of time. This vector can therefore be regarded as a minimal model system for studying the epigenetic regulation of replication and functional nuclear architecture. In theory, this construct represents an almost "ideal" expression system for gene therapy. In practice, S/MAR-based vectors stably modify mammalian cells with efficiencies far below those of virus-based constructs. Consequently, they have not yet found application in gene therapy trials. Furthermore, S/MAR vector systems are not trivial to handle and several critical technical issues have to be considered when modifying these vectors for various applications.

  3. Decays of the vector glueball

    CERN Document Server

    Giacosa, Francesco; Janowski, Stanislaus

    2016-01-01

    We calculate two- and three-body decays of the (lightest) vector glueball into (pseudo)scalar, (axial-)vector, as well as pseudovector and excited vector mesons. By setting the mass of this yet hypothetical vector glueball to 3.8 GeV as predicted by Lattice QCD, many branching ratios can be computed and represent a parameter-free prediction of our approach. We find that the decay mode $\\omega\\pi\\pi$ should be one of the largest (both through the decay chain $\\mathcal{O}\\rightarrow b_{1}\\pi\\rightarrow$ $\\omega\\pi\\pi$ and through the direct coupling $\\mathcal{O}\\rightarrow\\omega\\pi\\pi$)$.$ Similarly, the (direct and indirect) decay into $\\pi KK^{\\ast}(892)$ is sizable. Moreover, the decays into $\\rho\\pi$ and $K^{\\ast}(892)K$ are, although subleading, possible and could play a role in explaining the $\\rho\\pi$ puzzle of the charmonium state $\\psi(2S)$ thank to a (small) mixing with the vector glueball. The vector glueball can be directly formed at the ongoing BESIII experiment as well as at the future PANDA exper...

  4. Containment of arthropod disease vectors.

    Science.gov (United States)

    Scott, Thomas W

    2005-01-01

    Effective containment of arthropod vectors of infectious diseases is necessary to prevent transmission of pathogens by released, infected vectors and to prevent vectors that escape from establishing populations that subsequently contribute to increased disease. Although rare, past releases illustrate what can go wrong and justify the need for guidelines that minimize risks. An overview of recommendations for insectary facilities, practices, and equipment is provided, and features of four recently published and increasingly rigorous arthropod containment levels (ACLs 1-4) are summarized. ACL-1 is appropriate for research that constitutes the lowest risk level, including uninfected arthropods or vectors that are infected with micro-organisms that do not cause disease in humans, domestic animals, or wildlife. ACL-2 is appropriate for indigenous and exotic arthropods that represent a moderate risk, including vectors infected or suspected of being infected with biosafety level (BSL)-2 infectious agents and arthropods that have been genetically modified in ways that do not significantly affect their fecundity, survival, host preference, or vector competence. ACL-3 is recommended for arthropods that are or may be infected with BSL-3 infectious agents. ACL-3 places greater emphasis on pathogen containment and more restricted access to the insectary than ACL-2. ACL-4 is intended for arthropods that are infected with the most dangerous BSL-4 infectious agents, which can cause life-threatening illness by aerosol or arthropod bite. Adherence to these guidelines will result in laboratory-based arthropod vector research that minimizes risks and results in important new contributions to applied and basic science.

  5. Black holes with vector hair

    Science.gov (United States)

    Fan, Zhong-Ying

    2016-09-01

    In this paper, we consider Einstein gravity coupled to a vector field, either minimally or non-minimally, together with a vector potential of the type V = 2{Λ}_0+1/2{m}^2{A}^2 + {γ}_4{A}^4 . For a simpler non-minimally coupled theory with Λ0 = m = γ4 = 0, we obtain both extremal and non-extremal black hole solutions that are asymptotic to Minkowski space-times. We study the global properties of the solutions and derive the first law of thermodynamics using Wald formalism. We find that the thermodynamical first law of the extremal black holes is modified by a one form associated with the vector field. In particular, due to the existence of the non-minimal coupling, the vector forms thermodynamic conjugates with the graviton mode and partly contributes to the one form modifying the first law. For a minimally coupled theory with Λ0 ≠ 0, we also obtain one class of asymptotically flat extremal black hole solutions in general dimensions. This is possible because the parameters ( m 2 , γ4) take certain values such that V = 0. In particular, we find that the vector also forms thermodynamic conjugates with the graviton mode and contributes to the corresponding first law, although the non-minimal coupling has been turned off. Thus all the extremal black hole solutions that we obtain provide highly non-trivial examples how the first law of thermodynamics can be modified by a either minimally or non-minimally coupled vector field. We also study Gauss-Bonnet gravity non-minimally coupled to a vector and obtain asymptotically flat black holes and Lifshitz black holes.

  6. Project Physics Programmed Instruction, Vectors 1.

    Science.gov (United States)

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    This programmed instruction booklet is an interim version of instructional materials being developed by Harvard Project Physics. It is the first in a series of three booklets on vectors and covers the definitions of vectors and scalars, drawing vector quantities to scale, and negative vectors. For others in this series, see SE 015 550 and SE 015…

  7. Project Physics Programmed Instruction, Vectors 2.

    Science.gov (United States)

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    This is the second of a series of three programmed instruction booklets on vectors developed by Harvard Project Physics. It covers adding two or more vectors together, and finding a third vector that could be added to two given vectors to make a sum of zero. For other booklets in this series, see SE 015 549 and SE 015 551. (DT)

  8. The Duality on Vector Optimization Problems

    Institute of Scientific and Technical Information of China (English)

    HUANG Long-guang

    2012-01-01

    Duality framework on vector optimization problems in a locally convex topological vector space are established by using scalarization with a cone-strongly increasing function.The dualities for the scalar convex composed optimization problems and for general vector optimization problems are studied.A general approach for studying duality in vector optimization problems is presented.

  9. A NOTE ON VECTOR CASCADE ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    Qiu-hui Chen; Jin-zhao Liu; Wen-sheng Zhang

    2002-01-01

    The focus of this paper is on the relationship between accuracy of multivariate refinable vector and vector cascade algorithm. We show that, if the vector cascade algorithm (1.5) with isotropic dilation converges to a vector-valued function with regularity, then the initial function must satisfy the Strang-Fix conditions.

  10. The biological control of disease vectors.

    Science.gov (United States)

    Okamoto, Kenichi W; Amarasekare, Priyanga

    2012-09-21

    Vector-borne diseases are common in nature and can have a large impact on humans, livestock and crops. Biological control of vectors using natural enemies or competitors can reduce vector density and hence disease transmission. However, the indirect interactions inherent in host-vector disease systems make it difficult to use traditional pest control theory to guide biological control of disease vectors. This necessitates a conceptual framework that explicitly considers a range of indirect interactions between the host-vector disease system and the vector's biological control agent. Here we conduct a comparative analysis of the efficacy of different types of biological control agents in controlling vector-borne diseases. We report three key findings. First, highly efficient predators and parasitoids of the vector prove to be effective biological control agents, but highly virulent pathogens of the vector also require a high transmission rate to be effective. Second, biocontrol agents can successfully reduce long-term host disease incidence even though they may fail to reduce long-term vector densities. Third, inundating a host-vector disease system with a natural enemy of the vector has little or no effect on reducing disease incidence, but inundating the system with a competitor of the vector has a large effect on reducing disease incidence. The comparative framework yields predictions that are useful in developing biological control strategies for vector-borne diseases. We discuss how these predictions can inform ongoing biological control efforts for host-vector disease systems.

  11. Implementing Bayesian Vector Autoregressions Implementing Bayesian Vector Autoregressions

    Directory of Open Access Journals (Sweden)

    Richard M. Todd

    1988-03-01

    Full Text Available Implementing Bayesian Vector Autoregressions This paper discusses how the Bayesian approach can be used to construct a type of multivariate forecasting model known as a Bayesian vector autoregression (BVAR. In doing so, we mainly explain Doan, Littermann, and Sims (1984 propositions on how to estimate a BVAR based on a certain family of prior probability distributions. indexed by a fairly small set of hyperparameters. There is also a discussion on how to specify a BVAR and set up a BVAR database. A 4-variable model is used to iliustrate the BVAR approach.

  12. Vector Encoding in Biochemical Networks

    Science.gov (United States)

    Potter, Garrett; Sun, Bo

    Encoding of environmental cues via biochemical signaling pathways is of vital importance in the transmission of information for cells in a network. The current literature assumes a single cell state is used to encode information, however, recent research suggests the optimal strategy utilizes a vector of cell states sampled at various time points. To elucidate the optimal sampling strategy for vector encoding, we take an information theoretic approach and determine the mutual information of the calcium signaling dynamics obtained from fibroblast cells perturbed with different concentrations of ATP. Specifically, we analyze the sampling strategies under the cases of fixed and non-fixed vector dimension as well as the efficiency of these strategies. Our results show that sampling with greater frequency is optimal in the case of non-fixed vector dimension but that, in general, a lower sampling frequency is best from both a fixed vector dimension and efficiency standpoint. Further, we find the use of a simple modified Ornstein-Uhlenbeck process as a model qualitatively captures many of our experimental results suggesting that sampling in biochemical networks is based on a few basic components.

  13. Ensemble Dynamics and Bred Vectors

    CERN Document Server

    Balci, Nusret; Restrepo, Juan M; Sell, George R

    2011-01-01

    We introduce the new concept of an EBV to assess the sensitivity of model outputs to changes in initial conditions for weather forecasting. The new algorithm, which we call the "Ensemble Bred Vector" or EBV, is based on collective dynamics in essential ways. By construction, the EBV algorithm produces one or more dominant vectors. We investigate the performance of EBV, comparing it to the BV algorithm as well as the finite-time Lyapunov Vectors. We give a theoretical justification to the observed fact that the vectors produced by BV, EBV, and the finite-time Lyapunov vectors are similar for small amplitudes. Numerical comparisons of BV and EBV for the 3-equation Lorenz model and for a forced, dissipative partial differential equation of Cahn-Hilliard type that arises in modeling the thermohaline circulation, demonstrate that the EBV yields a size-ordered description of the perturbation field, and is more robust than the BV in the higher nonlinear regime. The EBV yields insight into the fractal structure of th...

  14. Gauge Theories of Vector Particles

    Science.gov (United States)

    Glashow, S. L.; Gell-Mann, M.

    1961-04-24

    The possibility of generalizing the Yang-Mills trick is examined. Thus we seek theories of vector bosons invariant under continuous groups of coordinate-dependent linear transformations. All such theories may be expressed as superpositions of certain "simple" theories; we show that each "simple theory is associated with a simple Lie algebra. We may introduce mass terms for the vector bosons at the price of destroying the gauge-invariance for coordinate-dependent gauge functions. The theories corresponding to three particular simple Lie algebras - those which admit precisely two commuting quantum numbers - are examined in some detail as examples. One of them might play a role in the physics of the strong interactions if there is an underlying super-symmetry, transcending charge independence, that is badly broken. The intermediate vector boson theory of weak interactions is discussed also. The so-called "schizon" model cannot be made to conform to the requirements of partial gauge-invariance.

  15. Vector bundles on toric varieties

    CERN Document Server

    Gharib, Saman

    2011-01-01

    Following Sam Payne's work, we study the existence problem of nontrivial vector bundles on toric varieties. The first result we prove is that every complete fan admits a nontrivial conewise linear multivalued function. Such functions could potentially be the Chern classes of toric vector bundles. Then we use the results of Corti\\~nas, Haesemeyer, Walker and Weibel to show that the (non-equivariant) Grothendieck group of the toric 3-fold studied by Payne is large, so the variety has a nontrivial vector bundle. Using the same computation, we show that every toric 3-fold X either has a nontrivial line bundle, or there is a finite surjective toric morphism from Y to X, such that Y has a large Grothendieck group.

  16. 3-D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Holbek, Simon

    studies and in vivo. Phantom measurements are compared with their corresponding reference value, whereas the in vivo measurement is validated against the current golden standard for non-invasive blood velocity estimates, based on magnetic resonance imaging (MRI). The study concludes, that a high precision......, if this significant reduction in the element count can still provide precise and robust 3-D vector flow estimates in a plane. The study concludes that the RC array is capable of estimating precise 3-D vector flow both in a plane and in a volume, despite the low channel count. However, some inherent new challenges......For the last decade, the field of ultrasonic vector flow imaging has gotten an increasingly attention, as the technique offers a variety of new applications for screening and diagnostics of cardiovascular pathologies. The main purpose of this PhD project was therefore to advance the field of 3-D...

  17. Skyrmions with vector mesons revisited

    CERN Document Server

    Oh, Yongseok

    2014-01-01

    In order to develop a model that can describe both a single baryon and multi-baryon systems on the same footing, we re-investigate the Skyrme model in a chiral Lagrangian derived from the hidden local symmetry (HLS) up to $O(p^4)$ including the homogeneous Wess-Zumino terms. We use the master formulas that connect the parameters of the HLS Lagrangian and a class of holographic QCD models, which provides a controllable way to determine the low-energy constants of the Lagrangian once the pion decay constant and the vector meson mass are given. Therefore, this model allows us to study the role of vector mesons in the skyrmion structure. We find that the $\\rho$ and $\\omega$ vector mesons have different roles in the skyrmion structure and that the $\\omega$ meson has an important role in the properties of the nucleon.

  18. Quantum contextuality for rational vectors

    CERN Document Server

    Cabello, Adan

    2010-01-01

    The Kochen-Specker theorem states that noncontextual hidden variable models are inconsistent with the quantum predictions for every yes-no question on a qutrit, corresponding to every projector in three dimensions. It has been suggested [D. A. Meyer, Phys. Rev. Lett. 83, 3751 (1999)] that the inconsistency would disappear when we are restricted to projectors on unit vectors with rational components; that noncontextual hidden variables could reproduce the quantum predictions for rational vectors. Here we show that a qutrit state with rational components violates an inequality valid for noncontextual hidden-variable models [A. A. Klyachko et al., Phys. Rev. Lett. 101, 020403 (2008)] using rational projectors. This shows that the inconsistency remains even when using only rational vectors.

  19. 3D vector flow imaging

    DEFF Research Database (Denmark)

    Pihl, Michael Johannes

    The main purpose of this PhD project is to develop an ultrasonic method for 3D vector flow imaging. The motivation is to advance the field of velocity estimation in ultrasound, which plays an important role in the clinic. The velocity of blood has components in all three spatial dimensions, yet...... conventional methods can estimate only the axial component. Several approaches for 3D vector velocity estimation have been suggested, but none of these methods have so far produced convincing in vivo results nor have they been adopted by commercial manufacturers. The basis for this project is the Transverse...... on the TO fields are suggested. They can be used to optimize the TO method. In the third part, a TO method for 3D vector velocity estimation is proposed. It employs a 2D phased array transducer and decouples the velocity estimation into three velocity components, which are estimated simultaneously based on 5...

  20. Learning with Support Vector Machines

    CERN Document Server

    Campbell, Colin

    2010-01-01

    Support Vectors Machines have become a well established tool within machine learning. They work well in practice and have now been used across a wide range of applications from recognizing hand-written digits, to face identification, text categorisation, bioinformatics, and database marketing. In this book we give an introductory overview of this subject. We start with a simple Support Vector Machine for performing binary classification before considering multi-class classification and learning in the presence of noise. We show that this framework can be extended to many other scenarios such a

  1. Requirements for airborne vector gravimetry

    Science.gov (United States)

    Schwarz, K. P.; Colombo, O.; Hein, G.; Knickmeyer, E. T.

    1992-01-01

    The objective of airborne vector gravimetry is the determination of the full gravity disturbance vector along the aircraft trajectory. The paper briefly outlines the concept of this method using a combination of inertial and GPS-satellite data. The accuracy requirements for users in geodesy and solid earth geophysics, oceanography and exploration geophysics are then specified. Using these requirements, accuracy specifications for the GPS subsystem and the INS subsystem are developed. The integration of the subsystems and the problems connected with it are briefly discussed and operational methods are indicated that might reduce some of the stringent accuracy requirements.

  2. Vector Theory in Relativistic Thermodynamics

    Institute of Scientific and Technical Information of China (English)

    刘泽文

    1994-01-01

    It is pointed out that five defects occur in Planck-Einstein’s relativistic thermodynamics (P-E theory). A vector theory in relativistic thermodynamics (VTRT) is established. Defining the internal energy as a 4-vector, and supposing the entropy and the number of. particles to be invariants we have derived the transformations of all quantities, and subsequently got the Lagrangian and 4-D forms of thermodynamic laws. In order to test the new theory, several exact solutions with classical limits are given. The VTRT is free from the defects of the P-E theory.

  3. Some results on the one-dimensional linear wave equation with van der Pol type nonlinear boundary conditions and the Korteweg-de Vries-Burgers equation

    Science.gov (United States)

    Feng, Zhaosheng

    Many physical phenomena can be described by nonlinear models. The last few decades have seen an enormous growth of the applicability of nonlinear models and of the development of related nonlinear concepts. This has been driven by modern computer power as well as by the discovery of new mathematical techniques, which include two contrasting themes: (i) the theory of dynamical systems, most popularly associated with the study of chaos, and (ii) the theory of integrable systems associated, among other things, with the study of solitons. In this dissertation, we study two nonlinear models. One is the 1-dimensional vibrating string satisfying wtt - wxx = 0 with van der Pol boundary conditions. We formulate the problem into an equivalent first order Hyperbolic system, and use the method of characteristics to derive a nonlinear reflection relation caused by the nonlinear boundary conditions. Thus, the problem is reduced to the discrete iteration problem of the type un+1 = F( un). Periodic solutions are investigated, an invariant interval for the Abel equation is studied, and numerical simulations and visualizations with different coefficients are illustrated. The other model is the Korteweg-de Vries-Burgers (KdVB) equation. In this dissertation, we proposed two new approaches: One is what we currently call First Integral Method, which is based on the ring theory of commutative algebra. Applying the Hilbert-Nullstellensatz, we reduce the KdVB equation to a first-order integrable ordinary differential equation. The other approach is called the Coordinate Transformation Method, which involves a series of variable transformations. Some new results on the traveling wave solution are established by using these two methods, which not only are more general than the existing ones in the previous literature, but also indicate that some corresponding solutions presented in the literature contain errors. We clarify the errors and instead give a refined result.

  4. Scalar Calibration of Vector Magnetometers

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz;

    2000-01-01

    The calibration parameters of a vector magnetometer are estimated only by the use of a scalar reference magnetometer. The method presented in this paper differs from those previously reported in its linearized parametrization. This allows the determination of three offsets or signals in the absence...

  5. Vector ecology of equine piroplasmosis

    Science.gov (United States)

    Equine piroplasmosis (EP) is a disease of equidae including horses, donkeys, mules and zebras caused by either of two protozoan parasites, Theileria equi or Babesia caballi. These parasites are biologically transmitted between hosts via tick-vectors and although they have inherent differences, they ...

  6. SCALAR AND VECTOR IN COMPULATION

    Directory of Open Access Journals (Sweden)

    Valery F. Ochkov

    2013-01-01

    Full Text Available The article deals with two fundamental data types – scalar and vector (array, without the ability of working with them one cannot solve using computer school or university tasks in mathematics, physics, chemistry and other technical training courses. Some fundamentals of teaching computer science at school and university are covered as well. 

  7. Vector-valued fuzzy multifunctions

    Directory of Open Access Journals (Sweden)

    Ismat Beg

    2001-01-01

    Full Text Available Some of the properties of vector-valued fuzzy multifunctions are studied. The notion of sum fuzzy multifunction, convex hull fuzzy multifunction, close convex hull fuzzy multifunction, and upper demicontinuous are given, and some of the properties of these fuzzy multifunctions are investigated.

  8. Portfolio Analysis for Vector Calculus

    Science.gov (United States)

    Kaplan, Samuel R.

    2015-01-01

    Classic stock portfolio analysis provides an applied context for Lagrange multipliers that undergraduate students appreciate. Although modern methods of portfolio analysis are beyond the scope of vector calculus, classic methods reinforce the utility of this material. This paper discusses how to introduce classic stock portfolio analysis in a…

  9. Sparse Matrix Vector Processing Formats

    NARCIS (Netherlands)

    Stathis, P.T.

    2004-01-01

    In this dissertation we have identified vector processing shortcomings related to the efficient storing and processing of sparse matrices. To alleviate existent problems we propose two storage formats denoted as Block Based Compression Storage (BBCS) format and Hierarchical Sparse Matrix (HiSM) stor

  10. Bifurcations of optimal vector fields

    NARCIS (Netherlands)

    Kiseleva, T.; Wagener, F.

    2015-01-01

    We study the structure of the solution set of a class of infinite-horizon dynamic programming problems with one-dimensional state spaces, as well as their bifurcations, as problem parameters are varied. The solutions are represented as the integral curves of a multivalued optimal vector field on sta

  11. Phlebotomine Vectors of Human Disease.

    Science.gov (United States)

    1983-12-30

    different. We refrain from naming this specimen until more material becomes available. 12. Lutzomyia olmeca bicolor Fairchild and Theodor 1971...Castillo (1958) and Arzube (1960). Lutzomyia olmeca bicolor is the suspected vector of Leishmania mexicana aristedesi among rodents and marsupials in

  12. Vector-meson dominance revisited

    Directory of Open Access Journals (Sweden)

    Terschlüsen Carla

    2012-12-01

    Full Text Available The interaction of mesons with electromagnetism is often well described by the concept of vector-meson dominance (VMD. However, there are also examples where VMD fails. A simple chiral Lagrangian for pions, rho and omega mesons is presented which can account for the respective agreement and disagreement between VMD and phenomenology in the sector of light mesons.

  13. Phase transitions in Vector Quantization

    NARCIS (Netherlands)

    Witoelar, Aree; Ghosh, Anarta; Biehl, Michael; Verleysen, Michel

    2008-01-01

    We study Winner-Takes-All and rank based Vector Quantization along the lines of the statistical physics of off-line learning. Typical behavior of the system is obtained within a model where high-dimensional training data are drawn from a mixture of Gaussians. The analysis becomes exact in the simpli

  14. Parallel Sparse Matrix - Vector Product

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Lazarov, Boyan Stefanov; Dammann, Bernd

    This technical report contains a case study of a sparse matrix-vector product routine, implemented for parallel execution on a compute cluster with both pure MPI and hybrid MPI-OpenMP solutions. C++ classes for sparse data types were developed and the report shows how these class can be used...

  15. The consequences of poor vectorization

    CERN Document Server

    CERN. Geneva

    2016-01-01

    This talk briefly discusses the vectorization problem and how it impacts scientific and engineering systems. A simple cost model of designing such system in context of different phases of software lifetime is considered. Finally a concept for scalable solution is presented.

  16. Vector Bundles over Elliptic Fibrations

    CERN Document Server

    Friedman, R; Witten, Edward; Friedman, Robert; Morgan, John W.; Witten, Edward

    1997-01-01

    This paper gives various methods for constructing vector bundles over elliptic curves and more generally over families of elliptic curves. We construct universal families over generalized elliptic curves via spectral cover methods and also by extensions, and then give a relative version of the construction in families. We give various examples and make Chern class computations.

  17. Large N Expansion. Vector Models

    CERN Document Server

    Nissimov, E; Nissimov, Emil; Pacheva, Svetlana

    2006-01-01

    Preliminary version of a contribution to the "Quantum Field Theory. Non-Perturbative QFT" topical area of "Modern Encyclopedia of Mathematical Physics" (SELECTA), eds. Aref'eva I, and Sternheimer D, Springer (2007). Consists of two parts - "main article" (Large N Expansion. Vector Models) and a "brief article" (BPHZL Renormalization).

  18. Burger, Marcel, Jérôme Jacquin & Raphaël Micheli (éds. 2011. La parole politique en confrontation dans les médias (Bruxelles : de Boeck, coll. Culture & Communication

    Directory of Open Access Journals (Sweden)

    Maria Brilliant

    2012-04-01

    Full Text Available Les contributions qui constituent cet ouvrage proviennent de champs divers s’apparentant aux sciences du langage ainsi qu’à celles de la communication. Ces points de vue variés portant tous sur le politique, la confrontation et les médias enrichissent la recherche en la situant au croisement d’une « interdisciplinarité focalisée ». Les auteurs de l’introduction (M. Burger, J. Jacquin, R. Micheli présentent la substance du questionnement : c’est sur la confrontation inhérente au discours poli...

  19. Vector variational inequalities and their relations with vector optimization

    Directory of Open Access Journals (Sweden)

    Surjeet Kaur Suneja

    2014-01-01

    Full Text Available In this paper, K- quasiconvex, K- pseudoconvex and other related functions have been introduced in terms of their Clarke subdifferentials, where is an arbitrary closed convex, pointed cone with nonempty interior. The (strict, weakly -pseudomonotonicity, (strict K- naturally quasimonotonicity and K- quasimonotonicity of Clarke subdifferential maps have also been defined. Further, we introduce Minty weak (MVVIP and Stampacchia weak (SVVIP vector variational inequalities over arbitrary cones. Under regularity assumption, we have proved that a weak minimum solution of vector optimization problem (VOP is a solution of (SVVIP and under the condition of K- pseudoconvexity we have obtained the converse for MVVIP (SVVIP. In the end we study the interrelations between these with the help of strict K-naturally quasimonotonicity of Clarke subdifferential map.

  20. Vector-Boson Fusion and Vector-Boson Scattering

    CERN Document Server

    Rauch, Michael

    2016-01-01

    Vector-boson fusion and vector-boson scattering are an important class of processes for the Large Hadron Collider at CERN. It is characterized by two high-energetic jets in the forward regions of the detector and reduced jet activity in the central region. The higher center-of-mass energy during the current and subsequent runs strongly boosts the sensitivity in these processes and allows to test the predictions of the Standard Model to a high precision. In this review, we first present the main phenomenological features of vector-boson fusion and scattering processes. Then we discuss the effects of higher-order corrections, which are available at NLO QCD for all processes and up to N3LO QCD and NLO electro-weak for VBF-H production. An additional refinement is the addition of parton-shower effects, where recently a lot of progress has been made. The appearance of triple and quartic gauge vertices in the production processes enables us to probe anomalous gauge couplings. We introduce and compare the different ...

  1. On third order integrable vector Hamiltonian equations

    Science.gov (United States)

    Meshkov, A. G.; Sokolov, V. V.

    2017-03-01

    A complete list of third order vector Hamiltonian equations with the Hamiltonian operator Dx having an infinite series of higher conservation laws is presented. A new vector integrable equation on the sphere is found.

  2. SYSTEM OF GENERALIZED VECTOR VARIATIONAL INEQUALITIES

    Institute of Scientific and Technical Information of China (English)

    Fang Yaping; Huang Nanjing

    2005-01-01

    In this paper, the authors introduce and study system of generalized vector variational inequalities. Under suitable conditions, the existence of solutions for system of generalized vector variational inequalities is presented by Kakutani-Fan-Glicksberg fixed point theorem.

  3. Symbolic Vector Analysis in Plasma Physics

    Energy Technology Data Exchange (ETDEWEB)

    Qin, H.; Tang, W.M.; Rewoldt, G.

    1997-10-09

    Many problems in plasma physics involve substantial amounts of analytical vector calculation. The complexity usually originates from both the vector operations themselves and the choice of underlying coordinate system. A computer algebra package for symbolic vector analysis in general coordinate systems, General Vector Analysis (GVA), is developed using Mathematica. The modern viewpoint for 3D vector calculus, differential forms on 3-manifolds, is adopted to unify and systematize the vector calculus operations in general coordinate systems. This package will benefit physicists and applied mathematicians in their research where complicated vector analysis is required. It will not only save a huge amount of human brain-power and dramatically improve accuracy, but this package will also be an intelligent tool to assist researchers in finding the right approaches to their problems. Several applications of this symbolic vector analysis package to plasma physics are also given.

  4. Symbolic Vector Analysis in Plasma Physics

    Energy Technology Data Exchange (ETDEWEB)

    Qin, H.; Rewoldt, G.; Tang, W.M.

    1997-10-01

    Many problems in plasma physics involve substantial amounts of analytical vector calculation. The complexity usually originates from both the vector operations themselves and the choice of underlying coordinate system. A computer algebra package for symbolic vector analysis in general coordinate systems, GeneralVectorAnalysis (GVA), is developed using Mathematica. The modern viewpoint for 3D vector calculus, differential forms on 3-manifolds, is adopted to unify and systematize the vector calculus operations in general coordinate systems. This package will benefit physicists and applied mathematicians in their research where complicated vector analysis is required. It will not only save a huge amount of human brain-power and dramatically improve accuracy, but this package will also be an intelligent tool to assist researchers in finding the right approaches to their problems. Several applications of this symbolic vector analysis package to plasma physics are also given.

  5. Vectors and translations in mathematics and physics

    OpenAIRE

    Dorier, Jean-Luc

    2016-01-01

    In mathematics, students learn about vectors and translation, in physics they model forces, speed, acceleration, etc. with vectors and study movements of translation. Do they make the connection between these concepts introduced in different disciplines or do they put things in separate boxes? In this paper we will start with some partial considerations on the history of vectors and we will give some references. Then we will show some examples of naïve illustrations of vectors from physics in...

  6. NEVILLE-TYPE VECTOR VALUED RATIONAL INTERPOLANTS

    Institute of Scientific and Technical Information of China (English)

    陈之兵; 顾传青; 徐晨

    2004-01-01

    A new kind of vector valued rational interpolants is established by means of Samelson inverse, with scalar numerator and vector valued denominator. It is essen tially different from that of Graves-Morris(1983), where the interpolants are constructed by Thiele-type continued fractions with vector valued numerator and scalar denominator. The new approach is more suitable to calculate the value of a vector valued function for a given point. And an error formula is also given and proven.

  7. Gene targeting with retroviral vectors

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.; Bernstein, A. (Toronto Univ., ON (Canada))

    1989-04-01

    The authors have designed and constructed integration-defective retroviral vectors to explore their potential for gene targeting in mammalian cells. Two nonoverlapping deletion mutants of the bacterial neomycin resistance (neo) gene were used to detect homologous recombination events between viral and chromosomal sequences. Stable neo gene correction events were selected at a frequency of approximately 1 G418/sup r/ cell per 3 x 10/sup 6/ infected cells. Analysis of the functional neo gene in independent targeted cell clones indicated that unintegrated retroviral linear DNA recombined with the target by gene conversion for variable distances into regions of nonhomology. In addition, transient neo gene correction events which were associated with the complete loss of the chromosomal target sequences were observed. These results demonstrated that retroviral vectors can recombine with homologous chromosomal sequences in rodent and human cells.

  8. Clinical applications of power vectors.

    Science.gov (United States)

    Miller, Joseph M

    2009-06-01

    The study of infant vision is closely coupled to the study of the refraction, change in refraction over time, and the effect of spectacle correction on visual development. Frequently, reports are limited to descriptions of spherical equivalent or cylinder power without regard to axis, as data are frequently collected in the clinical format of sphere, cylinder, and axis (S, C, A). Conversion from clinical notation to a power vector representation of refraction allows unambiguous description of how refractions change over time and differ between repeated measurements. This article presents a series of examples of Microsoft Excel spreadsheet formulas that make the conversion from clinical notation to power vector format, and provides examples of useful applications of these methods.

  9. ELVIS - ELectromagnetic Vector Information Sensor

    CERN Document Server

    Bergman, J E S; Thidé, B; Ananthakrishnan, S; Wahlund, J E; Karlsson, R L; Puccio, W; Carozzi, T D; Kale, P

    2005-01-01

    The ELVIS instrument was recently proposed by the authors for the Indian Chandrayaan-1 mission to the Moon and is presently under consideration by the Indian Space Research Organisation (ISRO). The scientific objective of ELVIS is to explore the electromagnetic environment of the moon. ELVIS samples the full three-dimensional (3D) electric field vector, E(x,t), up to 18 MHz, with selective Nyqvist frequency bandwidths down to 5 kHz, and one component of the magnetic field vector, B(x,t), from a few Hz up to 100 kHz.As a transient detector, ELVIS is capable of detecting pulses with a minimum pulse width of 5 ns. The instrument comprises three orthogonal electric dipole antennas, one magnetic search coil antenna and a four-channel digital sampling system, utilising flexible digital down conversion and filtering together with state-of-the-art onboard digital signal processing.

  10. Lentiviral vectors in cancer immunotherapy.

    Science.gov (United States)

    Oldham, Robyn Aa; Berinstein, Elliot M; Medin, Jeffrey A

    2015-01-01

    Basic science advances in cancer immunotherapy have resulted in various treatments that have recently shown success in the clinic. Many of these therapies require the insertion of genes into cells to directly kill them or to redirect the host's cells to induce potent immune responses. Other analogous therapies work by modifying effector cells for improved targeting and enhanced killing of tumor cells. Initial studies done using γ-retroviruses were promising, but safety concerns centered on the potential for insertional mutagenesis have highlighted the desire to develop other options for gene delivery. Lentiviral vectors (LVs) have been identified as potentially more effective and safer alternative delivery vehicles. LVs are now in use in clinical trials for many different types of inherited and acquired disorders, including cancer. This review will discuss current knowledge of LVs and the applications of this viral vector-based delivery vehicle to cancer immunotherapy.

  11. Ultrasonic Dynamic Vector Stress Sensor

    Science.gov (United States)

    Heyman, Joseph S.; Froggatt, Mark

    1992-01-01

    Stress inferred from measurements in specimens rather than in bonded gauges. Ultrasonic dynamic vector stress sensor (UDVSS) measures changes in dynamic directional stress occurring in material or structure at location touched by device when material or structure put under cyclic load. Includes phase-locked loop, synchronous amplifier, and contact probe. Useful among manufacturers of aerospace and automotive structures for stress testing and evaluation of designs.

  12. Biological rhythms and vector insects

    Directory of Open Access Journals (Sweden)

    Mirian David Marques

    2013-01-01

    Full Text Available The adjustment of all species, animals and plants, to the Earth’s cyclic environments is ensured by their temporal organisation. The relationships between parasites, vectors and hosts rely greatly upon the synchronisation of their biological rhythms, especially circadian rhythms. In this short note, parasitic infections by Protozoa and by microfilariae have been chosen as examples of the dependence of successful transmission mechanisms on temporal components.

  13. Vector and tensor analysis with applications

    CERN Document Server

    Borisenko, A I; Silverman, Richard A

    1979-01-01

    Concise and readable, this text ranges from definition of vectors and discussion of algebraic operations on vectors to the concept of tensor and algebraic operations on tensors. It also includes a systematic study of the differential and integral calculus of vector and tensor functions of space and time. Worked-out problems and solutions. 1968 edition.

  14. Project Physics Programmed Instruction, Vectors 3.

    Science.gov (United States)

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    This is the third of a series of three programmed instruction booklets on vectors developed by Harvard Project Physics. Separating vectors into components and obtaining a vector from its components are the topics covered. For other booklets in this series, see SE 015 549 and SE 015 550. (DT)

  15. Some Remarks on a Generalized Vector Product

    CERN Document Server

    Acosta-Humánez, Primitivo B; Núñez, Reinaldo

    2011-01-01

    In this paper we use a generalized vector product to construct an exterior form $\\wedge :(\\mathbb{R}^{n}) ^{k}\\to \\mathbb{R}^{\\binom{n}{k}}$, where $\\binom{n}{k}=\\frac{n!}{(n-k)!k!}$, $k\\leq n$. Finally, for $n=k-1$ we introduce the reversing operation to study this generalized vector product over palindromic and antipalindromic vectors.

  16. Vector Fields and Flows on Differentiable Stacks

    DEFF Research Database (Denmark)

    A. Hepworth, Richard

    2009-01-01

    This paper introduces the notions of vector field and flow on a general differentiable stack. Our main theorem states that the flow of a vector field on a compact proper differentiable stack exists and is unique up to a uniquely determined 2-cell. This extends the usual result on the existence...... of vector fields....

  17. 试析纳丁·戈迪默小说《伯格的女儿》中主人公罗莎的成长历程%AN ANALYSIS OF THE PROTAGNIST ROSA'S GROWTH IN NADINE GORDIMER'S BURGER'S DAUGHTER

    Institute of Scientific and Technical Information of China (English)

    周慧梅

    2015-01-01

    Burger's Daughter is one of Nadine Gordimer's most important novels. It describes the growing experience of a young lady, who is the daughter of a Communist. By applying the Bildungsroman theory, this thesis will explore the psychological changes of the heroine Rosa. At first, Rosa has a miserable childhood because of innocence. Then, she gets puzzled in "com-fortable" life in Paris. Finally, Rosa finds her real identity. From Burger's Daughter, we can find that Nadine Gordimer always supports humanism and exposes the disaster and distortion of the human nature brought by apartheid system.%纳丁·戈迪默在小说《伯格的女儿》中描述了一位年轻女性——共产党员伯格的女儿罗莎的成长经历.文章通过运用"成长理论",探讨罗莎的心路历程的三个阶段:起初,无知带来的悲惨童年;其后,在"舒适"的巴黎生活中困惑;最终,在顿悟中找到了真正的自己. 戈迪默始终坚持人道主义观点,深刻剖析黑暗的种族隔离制度给人类带来的灾难和人性的扭曲.

  18. On the Distribution of Norm of Vector Projection and Rejection of Two Complex Normal Random Vectors

    Directory of Open Access Journals (Sweden)

    Mehdi Maleki

    2015-01-01

    Full Text Available Vector projection and vector rejection are highly common and useful operations in mathematics, information theory, and signal processing. In this paper, we find the distribution of the norm of projection and rejection vectors when the original vectors are standard complex normally distributed.

  19. Problems and worked solutions in vector analysis

    CERN Document Server

    Shorter, LR

    2014-01-01

    ""A handy book like this,"" noted The Mathematical Gazette, ""will fill a great want."" Devoted to fully worked out examples, this unique text constitutes a self-contained introductory course in vector analysis for undergraduate and graduate students of applied mathematics.Opening chapters define vector addition and subtraction, show how to resolve and determine the direction of two or more vectors, and explain systems of coordinates, vector equations of a plane and straight line, relative velocity and acceleration, and infinitely small vectors. The following chapters deal with scalar and vect

  20. DBSC-Based Grayscale Line Image Vectorization

    Institute of Scientific and Technical Information of China (English)

    Konstantin Melikhov; Feng Tian; Jie Qiu; Quan Chen; Hock Soon Seah

    2006-01-01

    Vector graphics plays an important role in computer animation and imaging technologies. However present techniques and tools cannot fully replace traditional pencil and paper. Additionally, vector representation of an image is not always available. There is not yet a good solution for vectorizing a picture drawn on a paper. This work attempts to solve the problem of vectorizing grayscale line drawings. The solution proposed uses Disk B-Spline curves to represent strokes of an image in vector form. The algorithm builds a vector representation from a grayscale raster image, which can be a scanned picture for instance. The proposed method uses a Gaussian sliding window to calculate skeleton and perceptive width of a stroke. As a result of vectorization, the given image is represented by a set of Disk B-Spline curves.

  1. The vector algebra war: A historical perspective

    CERN Document Server

    Chappell, James M; Hartnett, John G; Abbott, Derek

    2015-01-01

    There are a wide variety of different vector formalisms currently utilized in science. For example, Gibbs three-vectors, spacetime four-vectors, complex spinors for quantum mechanics, quaternions used for rigid body rotations and Clifford multivectors. With such a range of vector formalisms in use, it thus appears that there is as yet no general agreement on a vector formalism suitable for the whole of science. This surprising situation exists today, despite the fact that one of the main goals of nineteenth century science was to correctly describe vectors and the algebra of three-dimensional space. This situation has also had the unfortunate consequence of fragmenting knowledge across many disciplines and requiring a very significant amount of time and effort in learning the different formalisms. We thus review historically the development of our various vector systems and conclude that the Clifford algebra multivector fulfills the goal of correctly describing vectorial quantities in three dimensions.

  2. Some theoretical comparisons of refined Ritz vectors and Ritz vectors

    Institute of Scientific and Technical Information of China (English)

    JIA Zhongxiao

    2004-01-01

    Refined projection methods proposed by the author have received attention internationally. We are concerned with a conventional projection method and its refined counterpart for computing approximations to a simple eigenpair (λ,x)of a large matrix A. Given a subspace w that contains anapproximation to x, these two methods compute approximations(μ(x~)) and (μ(x^)) to (λ,x),respectively. We establish three results. First, the refinedeigenvector approximation or simply the refined Ritz vector (x^) is unique as the deviation of x from w approaches zero if λ is simple. Second, interms of residual norm of the refined approximate eigenpair (μ,(x^)), we derive lower and upper bounds for the sine of the angle betweenthe Ritz vector (x~) and the refined eigenvector approximation (x^), and we prove that (x~)≠(x^) unless (x^)=x. Third, we establish relationships between theresidual norm ‖A(x~)-μ(x^)‖ of the conventionalmethods and the residual norm ‖A(x^)-μ(x^)‖ of therefined methods, and we show that the latter is always smallerthan the former if (μ,(x^)) is not an exact eigenpair ofA, indicating that the refined projection method is superiorto the corresponding conventional counterpart.

  3. Some theoretical comparisons of refined Ritz vectors and Ritz vectors

    Institute of Scientific and Technical Information of China (English)

    JIA; Zhongxiao

    2004-01-01

    Refined projection methods proposed by the author have received attention internationally. We are concerned with a conventional projection method and its refined counterpart for computing approximations to a simple eigenpair (λ,x)of a large matrix A. Given a subspace w that contains anapproximation to x, these two methods compute approximations(μ(x~)) and (μ(x)) to (λ,x),respectively. We establish three results. First, the refinedeigenvector approximation or simply the refined Ritz vector (x) is unique as the deviation of x from w approaches zero if λ is simple. Second, interms of residual norm of the refined approximate eigenpair (μ,(x)), we derive lower and upper bounds for the sine of the angle betweenthe Ritz vector (x~) and the refined eigenvector approximation (x), and we prove that (x~)≠(x) unless (x)=x. Third, we establish relationships between theresidual norm ‖A(x~)-μ(x)‖ of the conventionalmethods and the residual norm ‖A(x)-μ(x)‖ of therefined methods, and we show that the latter is always smallerthan the former if (μ,(x)) is not an exact eigenpair ofA, indicating that the refined projection method is superiorto the corresponding conventional counterpart.

  4. Vector meson electroproduction in QCD

    Science.gov (United States)

    Lu, Juan; Cai, Xian-Hao; Zhou, Li-Juan

    2012-08-01

    Based on the generalized QCD vector meson dominance model, we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model. Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for ρ, ω and varphi meson electroproduction in this paper. Since gluons interact among themselves (self-interaction), two gluons can form a glueball with quantum numbers IG, JPC = 0+,2++, decay width Γt ≈ 100 MeV, and mass of mG = 2.23 GeV. The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C = -1, called the Odderon. The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon. Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully, which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton. It should be emphasized that our mechanism is different from the theoretical framework of Block et al. We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies, as well as for searching for new particles such as tensor glueballs and Odderons, which have been predicted by QCD and the color glass condensate model (CGC). Therefore, in return, it can test the validity of QCD and the CGC model.

  5. Vector meson electroproduction in QCD

    Institute of Scientific and Technical Information of China (English)

    LU Juan; CAI Xian-Hao; ZHOU Li-Juan

    2012-01-01

    Based on the generalized QCD vector meson dominance model,we study the electroproduction of a vector meson off a proton in the QCD inspired eikonalized model.Numerical calculations for the total cross section σtot and differential cross section dσ/dt are performed for p,ω and φ meson electroproduction in this paper.Since gluons interact among themselves (self-interaction),two gluons can form a glueball with quantum numbers IG,JPC =0+,2++,decay width Γt ≈ 100 MeV,and mass of mG=2.23 GeV.The three gluons can form a three-gluon colorless bound state with charge conjugation quantum number C =-1,called the Odderon.The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the virtual photon) and the proton target (a three-quark system) are the tensor glueball and the Odderon.Our calculated results in the tensor glueball and Odderon exchange model fit to the existing data successfully,which evidently shows that our present QCD mechanism is a good description of meson electroproduction off a proton.It should be emphasized that our mechanism is different from the theoretical framework of Block et al.We also believe that the present study and its success are important for the investigation of other vector meson electro- and photoproduction at high energies,as well as for searching for new particles such as tensor glueballs and Odderons,which have been predicted by QCD and the color glass condensate model (CGC).Therefore,in return,it can test the validity of QCD and the CGC model.

  6. On Weighted Support Vector Regression

    DEFF Research Database (Denmark)

    Han, Xixuan; Clemmensen, Line Katrine Harder

    2014-01-01

    We propose a new type of weighted support vector regression (SVR), motivated by modeling local dependencies in time and space in prediction of house prices. The classic weights of the weighted SVR are added to the slack variables in the objective function (OF‐weights). This procedure directly...... the differences and similarities of the two types of weights by demonstrating the connection between the Least Absolute Shrinkage and Selection Operator (LASSO) and the SVR. We show that an SVR problem can be transformed to a LASSO problem plus a linear constraint and a box constraint. We demonstrate...

  7. Probability Ranking in Vector Spaces

    CERN Document Server

    Melucci, Massimo

    2011-01-01

    The Probability Ranking Principle states that the document set with the highest values of probability of relevance optimizes information retrieval effectiveness given the probabilities are estimated as accurately as possible. The key point of the principle is the separation of the document set into two subsets with a given level of fallout and with the highest recall. The paper introduces the separation between two vector subspaces and shows that the separation yields a more effective performance than the optimal separation into subsets with the same available evidence, the performance being measured with recall and fallout. The result is proved mathematically and exemplified experimentally.

  8. Nonviral Vectors for Gene Delivery

    Science.gov (United States)

    Baoum, Abdulgader Ahmed

    2011-12-01

    The development of nonviral vectors for safe and efficient gene delivery has been gaining considerable attention recently. An ideal nonviral vector must protect the gene against degradation by nuclease in the extracellular matrix, internalize the plasma membrane, escape from the endosomal compartment, unpackage the gene at some point and have no detrimental effects. In comparison to viruses, nonviral vectors are relatively easy to synthesize, less immunogenic, low in cost, and have no limitation in the size of a gene that can be delivered. Significant progress has been made in the basic science and applications of various nonviral gene delivery vectors; however, the majority of nonviral approaches are still inefficient and often toxic. To this end, two nonviral gene delivery systems using either biodegradable poly(D,L-lactide- co-glycolide) (PLG) nanoparticles or cell penetrating peptide (CPP) complexes have been designed and studied using A549 human lung epithelial cells. PLG nanoparticles were optimized for gene delivery by varying particle surface chemistry using different coating materials that adsorb to the particle surface during formation. A variety of cationic coating materials were studied and compared to more conventional surfactants used for PLG nanoparticle fabrication. Nanoparticles (˜200 nm) efficiently encapsulated plasmids encoding for luciferase (80-90%) and slowly released the same for two weeks. After a delay, moderate levels of gene expression appeared at day 5 for certain positively charged PLG particles and gene expression was maintained for at least two weeks. In contrast, gene expression mediated by polyethyleneimine (PEI) ended at day 5. PLG particles were also significantly less cytotoxic than PEI suggesting the use of these vehicles for localized, sustained gene delivery to the pulmonary epithelium. On the other hand, a more simple method to synthesize 50-200 nm complexes capable of high transfection efficiency or high gene knockdown was

  9. Vector-tensor and vector-vector decay amplitude analysis of B0-->phiK*0.

    Science.gov (United States)

    Aubert, B; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Pegna, D Lopes; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Sanchez, P del Amo; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Cheng, C H; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Vetere, M Lo; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Lee, C L; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Vazquez, W Panduro; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y; Gritsan, A V; Guo, Z J; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Diberder, F Le; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Clarke, C K; Lodovico, F Di; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; Nardo, G De; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Potter, C T; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Buono, L Del; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; del Re, D; Marco, E Di; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Gioi, L Li; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Tehrani, F Safai; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; Franek, B; Olaiya, E O; Ricciardi, S; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Ricca, G Della; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihalyi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2007-02-02

    We perform an amplitude analysis of the decays B(0)-->phiK*(2)(1430)(0), phiK*(892)(0), and phi(Kpi)(0)(S-wave) with a sample of about 384x10(6) BB[over ] pairs recorded with the BABAR detector. The fractions of longitudinal polarization f(L) of the vector-tensor and vector-vector decay modes are measured to be 0.853(-0.069+0.061)+/-0.036 and 0.506+/-0.040+/-0.015, respectively. Overall, twelve parameters are measured for the vector-vector decay and seven parameters for the vector-tensor decay, including the branching fractions and parameters sensitive to CP violation.

  10. On a nonhomogeneous Burgers' equation

    Institute of Scientific and Technical Information of China (English)

    DING; Xiaqi(

    2001-01-01

    [1]Hopf, E., The partial differential equation ut + uux = μuxx, Comm. Pure Appl. Math., 1950, 3: 201-230.[2]Ding, X. Q. , Luo, P. Z. , Generalized expansions in Hilbert space, Acta Mathematica Scientia, 1999, 19(3): 241 250.[3]Titchmarsh, E., Introduction to the Theory of Fourier Integrals, 2nd ed., Oxford: Oxford University Press, 1948.[4]Ladyzhenskaya, O. A., Solonnikov, V. A., Ural' ceva, N. N., Linear and Quasilinear Equations of Parabolic Type,Translations of Mathematical Monographs, Vol. 23, American Mathematical Society, 1968.

  11. Weinig Roodkapjesyndroom bij burgers Nijmegen

    NARCIS (Netherlands)

    Hilbers, J.P.; Boonman-Berson, S.H.; Elands, B.H.M.

    2011-01-01

    Volgens sommigen staat het vast dat de wolf Nederland binnen enkele jaren weer zal bereiken. Verondersteld wordt dat de wolven als eerste in de regio Nijmegen de grens over komen. Leerstoelgroep Bos- en Natuurbeleid van Wageningen Universiteit onderzocht de opvattingen van inwoners van Nijmegen ten

  12. Erfgoedconstructies in landschapspraktijken van burgers

    NARCIS (Netherlands)

    Braaksma, Patricia

    2017-01-01

    Decisions to cut down monumental trees or demolish historic buildings can always count on civilian protests. Every year, the Dutch tradition of Zwarte Piet (‘Black Pete’) is heavily debated, the protests almost a tradition themselves. There are regular reports about concerned people prot

  13. Therapeutic and prophylactic applications of alphavirus vectors.

    Science.gov (United States)

    Atkins, Gregory J; Fleeton, Marina N; Sheahan, Brian J

    2008-11-11

    Alphavirus vectors are high-level, transient expression vectors for therapeutic and prophylactic use. These positive-stranded RNA vectors, derived from Semliki Forest virus, Sindbis virus and Venezuelan equine encephalitis virus, multiply and are expressed in the cytoplasm of most vertebrate cells, including human cells. Part of the genome encoding the structural protein genes, which is amplified during a normal infection, is replaced by a transgene. Three types of vector have been developed: virus-like particles, layered DNA-RNA vectors and replication-competent vectors. Virus-like particles contain replicon RNA that is defective since it contains a cloned gene in place of the structural protein genes, and thus are able to undergo only one cycle of expression. They are produced by transfection of vector RNA, and helper RNAs encoding the structural proteins. Layered DNA-RNA vectors express the Semliki Forest virus replicon from a cDNA copy via a cytomegalovirus promoter. Replication-competent vectors contain a transgene in addition to the structural protein genes. Alphavirus vectors are used for three main applications: vaccine construction, therapy of central nervous system disease, and cancer therapy.

  14. Current progress of polymeric gene vectors

    Institute of Scientific and Technical Information of China (English)

    ZENG Xuan; SUN YunXia; ZHUO RenXi; ZHANG XianZheng

    2011-01-01

    After over 40 years ot progress,gene therapy provides great opportunities for treating diseases from various genetic disorders,infections and cancers.The success of gene therapy largely depends on the availability of suitable gene vectors.As an attractive alternative to virus-based gene therapy,non-viral gene delivery system has been developed and investigated due to their merits including low immunogenecity,convenient operability,and large-scale manufacturability [1].Because polycations can condense with DNA as a result of electrostatic interactions,form nanosize polyplexes,and protect DNA from degradation by DNase,cationic polymer becomes a major type of non-viral gene delivery vectors (Figure 1) [2].A wide range of polymeric vectors have been developed and investigated in the past decade,such as polyethylenimine (PEI)-based vectors,poly(L-lysine) (PLL)-based vectors,dendrimer-based vectors,polypeptide-based vectors,and chitosan-based vectors [3].However,unlike viral vectors that have the ability to infect host cells and overcome cellular barriers through the course of evolution,nonviral gene vectors exhibit Significantly reduced transfection efficiency as they are obstructed by various extra- and intracellular barriers,including serum proteins in blood stream,cell membrane,endosomal compartment and nuclear membrane [4].

  15. Vector-Resonance-Multimode Instability

    Science.gov (United States)

    Sergeyev, S. V.; Kbashi, H.; Tarasov, N.; Loiko, Yu.; Kolpakov, S. A.

    2017-01-01

    The modulation and multimode instabilities are the main mechanisms which drive spontaneous spatial and temporal pattern formation in a vast number of nonlinear systems ranging from biology to laser physics. Using an Er-doped fiber laser as a test bed, here for the first time we demonstrate both experimentally and theoretically a new type of a low-threshold vector-resonance-multimode instability which inherits features of multimode and modulation instabilities. The same as for the multimode instability, a large number of longitudinal modes can be excited without mode synchronization. To enable modulation instability, we modulate the state of polarization of the lasing signal with the period of the beat length by an adjustment of the in-cavity birefringence and the state of polarization of the pump wave. As a result, we show the regime's tunability from complex oscillatory to periodic with longitudinal mode synchronization in the case of resonance matching between the beat and cavity lengths. Apart from the interest in laser physics for unlocking the tunability and stability of dynamic regimes, the proposed mechanism of the vector-resonance-multimode instability can be of fundamental interest for the nonlinear dynamics of various distributed systems.

  16. The vector BPS Skyrme model

    CERN Document Server

    Adam, C; Sanchez-Guillen, J; Wereszczynski, A

    2012-01-01

    We analyze the vector meson formulation of the BPS Skyrme model in (3+1) dimensions, where the term of sixth power in first derivatives characteristic for the original, integrable BPS Skyrme model (the topological or baryon current squared) is replaced by a coupling between the vector meson $\\omega_\\mu$ and the baryon current. We find that the model remains integrable in the sense of generalized integrability and almost solvable (reducible to a set of two first order ODEs) for any value of the baryon charge. Further, we analyze the appearance of topological solitons for two one-parameter families of one vacuum potentials: the old Skyrme potentials and the so-called BPS potentials. Depending on the value of the parameters we find several qualitatively different possibilities. In the massless case we have a parameter region with no skyrmions, a unique compact skyrmion with a discontinuous first derivative at the boundary (equivalently, with a source term located at the boundary, which screens the topological ch...

  17. Design and Development of Intelligent Patrol System of Burger King%汉堡王智能巡店系统设计与开发

    Institute of Scientific and Technical Information of China (English)

    曹建国; 杨湘浩

    2016-01-01

    Shop inspection is an important link in the management of chain stores,playing the important role in control of the running state of all the stores, timely detection of problems, and improving the management efficiency. However, in the traditional shop inspection work,the phenomenon is not high inspection is a common problem. Based on Android system,GPS and 3G/4G communication technolo-gy,an intelligent patrol shop system was designed and developed,realization of the shop staff real-time positioning,wireless data retur-ning and tasks assigned patrol and other functions,the store supervisor ( manager) patrol work do electronic operation,graphical display, and intelligent management,effectively improving the mobility,flexibility,efficiency and accuracy for patrol job shops,significantly en-hancing the rapid response capability based on channel/terminal,which makes the headquarters regulation and middle level executive no longer appears fault,effectively improving the enterprise store standardization management level. At the same time,a good platform for the expansion of the business is to further expand the preparation. The system has been applied in Burger King ( China) Investment Co. , Ltd. patrol shop,which can supervise the patrol work shop in real-time and effectively,greatly reducing the management costs,and im-proving management efficiency.%店面巡视是连锁店总部管理的重要环节,承担掌握所有加盟店的运行状态、及时发现问题、提高管理效率的重要作用。然而在传统的店面巡视工作中,巡视到位率不高的现象是普遍存在的现实问题。文中基于Android系统、GPS定位与3G/4G通信技术,设计开发了智能巡店系统,实现了巡店人员实时定位、无线数据回传和任务下达等功能,使店铺督导(店长)的巡店工作做到“电子化作业、图形化展示、智能化管理”,有效提高巡店作业的移动性、灵活性、完成效率和准确率,显著加

  18. Transversals of Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    Dias, Kealey

    by rotational constants. Transversals are a certain class of curves for such a family of vector fields that represent the bifurcation states for this family of vector fields. More specifically, transversals are curves that coincide with a homoclinic separatrix for some rotation of the vector field. Given......, an important step was proving that the transversals possessed a certain characteristic. Understanding transversals might be the key to proving other polynomial vector fields are generic, and they are important in understanding bifurcations of polynomial vector fields in general. We consider two important...... examples of rotated families to argue this. There will be discussed several open questions concerning the number of transversals that can appear for a certain degree d of a polynomial vector field, and furthermore how transversals are analyzed with respect to bifurcations around multiple equilibrium points....

  19. A Modified Moist Ageostrophic Q Vector

    Institute of Scientific and Technical Information of China (English)

    YUE Caijun; SHOU Shaowen

    2008-01-01

    The quasi-geostrophic Q vector is an important diagnostic tool for studying development of surface rainfall associated with large-scale weather systems and is calculated using data at single vertical level. When ageostrophic Q vector was introduced, it required data at two vertical levels. In this study, moist ageostrophic Q vector is modified so that it can be calculated using data at a single vertical level. The comparison study between the original and modified moist ageostrophic Q vectors is conducted using the data from 5 to 6 July 1991 during the torrential rainfall event associated with the Changjiang-Huaihe mei-yu front in China. The results reveal that divergences of original and modified moist ageostrophic Q vectors have similar horizontal distributions and their centers are almost located in the precipitation centers. This indicates that modified moist ageostrophic Q vector can be used to diagnose convective development with reasonable accuracy.

  20. Higgs Decays and Brane Gravi-vectors

    OpenAIRE

    Clark, T. E.; Liu, B. Y.; Love, S. T.; Xiong, C.; ter Veldhuis, T.

    2008-01-01

    Higgs boson decays in flexible brane world models with stable, massive gravi-vectors are considered. Such vectors couple bilinearly to the Standard Model fields through either the Standard Model energy-momentum tensor, the weak hypercharge field strength or the Higgs scalar. The role of the coupling involving the extrinsic curvature is highlighted. It is found that within the presently allowed parameter space, the decay rate of the Higgs into two gravi-vectors (which would appear as an invisi...

  1. [Research progress on malaria vector control].

    Science.gov (United States)

    Zhu, Guo-Ding; Cao, Jun; Zhou, Hua-Yun; Gao, Qi

    2013-06-01

    Vector control plays a crucial role in the stages of malaria control and elimination. Currently, it mainly relies on the chemical control methods for adult mosquitoes in malaria endemic areas, however, it is undergoing the serious threat by insecticide resistance. In recent years, the transgenic technologies of malaria vectors have made a great progress in the laboratory. This paper reviews the challenges of the traditional methods and the rapid developed genetic modified technology in the application of vector control.

  2. Integrated epidemiology for vector-borne zoonoses

    OpenAIRE

    2016-01-01

    The development and application of interventions for the control of vector-borne zoonoses requires broad understanding of epidemiological linkages between vector, animal infection and human infection. However, there are significant gaps in our understanding of these linkages and a lack of appropriate data poses a considerable barrier to addressing this issue. A move towards strengthened surveillance of vectors and disease in both animal and human hosts, in combination with linked human-animal...

  3. Construction of shRNA lentiviral vector

    Directory of Open Access Journals (Sweden)

    Hong Song

    2010-12-01

    Full Text Available Lentiviruses have been adapted as gene delivery vehicles. This article summarized shRNA lentiviral vector methods generally used in research laboratories. The main procedures of shRNA lentiviral vector include that (1 Target sequences screening and shRNA oligonucleotides designing, (2 insert designed oligonucleotides into lentiviral vectors, (3 using packaging cells to produce shRNA lentivirus, and (4 transducing target cells with shRNA lentivirus.

  4. Genetic manipulation of endosymbionts to control vector and vector borne diseases

    Directory of Open Access Journals (Sweden)

    Jay Prakash Gupta

    Full Text Available Vector borne diseases (VBD are on the rise because of failure of the existing methods of control of vector and vector borne diseases and the climate change. A steep rise of VBDs are due to several factors like selection of insecticide resistant vector population, drug resistant parasite population and lack of effective vaccines against the VBDs. Environmental pollution, public health hazard and insecticide resistant vector population indicate that the insecticides are no longer a sustainable control method of vector and vector-borne diseases. Amongst the various alternative control strategies, symbiont based approach utilizing endosymbionts of arthropod vectors could be explored to control the vector and vector borne diseases. The endosymbiont population of arthropod vectors could be exploited in different ways viz., as a chemotherapeutic target, vaccine target for the control of vectors. Expression of molecules with antiparasitic activity by genetically transformed symbiotic bacteria of disease-transmitting arthropods may serve as a powerful approach to control certain arthropod-borne diseases. Genetic transformation of symbiotic bacteria of the arthropod vector to alter the vector’s ability to transmit pathogen is an alternative means of blocking the transmission of VBDs. In Indian scenario, where dengue, chikungunya, malaria and filariosis are prevalent, paratransgenic based approach can be used effectively. [Vet World 2012; 5(9.000: 571-576

  5. A New Incremental Support Vector Machine Algorithm

    Directory of Open Access Journals (Sweden)

    Wenjuan Zhao

    2012-10-01

    Full Text Available Support vector machine is a popular method in machine learning. Incremental support vector machine algorithm is ideal selection in the face of large learning data set. In this paper a new incremental support vector machine learning algorithm is proposed to improve efficiency of large scale data processing. The model of this incremental learning algorithm is similar to the standard support vector machine. The goal concept is updated by incremental learning. Each training procedure only includes new training data. The time complexity is independent of whole training set. Compared with the other incremental version, the training speed of this approach is improved and the change of hyperplane is reduced.

  6. Pro jective vector fields on Finsler manifolds

    Institute of Scientific and Technical Information of China (English)

    TIAN Huang-jia

    2014-01-01

    In this paper, we give the equation that characterizes projective vector fields on a Finsler manifold by the local coordinate. Moreover, we obtain a feature of the projective fields on the compact Finsler manifold with non-positive flag curvature and the non-existence of projective vector fields on the compact Finsler manifold with negative flag curvature. Furthermore, we deduce some expectable, but non-trivial relationships between geometric vector fields such as projective, affine, conformal, homothetic and Killing vector fields on a Finsler manifold.

  7. Vector perturbations of galaxy number counts

    Science.gov (United States)

    Durrer, Ruth; Tansella, Vittorio

    2016-07-01

    We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, where the Bardeen potentials are replaced with line-of-sight projection of vector and tensor quantities. Since vector and tensor perturbations do not lead to density fluctuations the standard density term in the number counts is absent. We apply our results to vector perturbations which are induced from scalar perturbations at second order and give numerical estimates of their contributions to the power spectrum of relativistic galaxy number counts.

  8. Vector perturbations of galaxy number counts

    CERN Document Server

    Durrer, Ruth

    2016-01-01

    We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, where the Bardeen potentials are replaced with line-of-sight projection of vector and tensor quantities. Since vector and tensor perturbations do not lead to density fluctuations the standard density term in the number counts is absent. We apply our results to vector perturbations which are induced from scalar perturbations at second order and give numerical estimates of their contributions to the power spectrum of relativistic galaxy number counts.

  9. Synthetic Aperture Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando

    The main objective of this project was to continue the development of a synthetic aperture vector flow estimator. This type of estimator is capable of overcoming two of the major limitations in conventional ultrasound systems: 1) the inability to scan large region of interest with high temporal...... resolutions; 2) the lack of capability in detecting flow other than the one along the direction of the beam. Addressing these technical limitations would translate in the clinic as a gain in valuable clinical information and a removal of operator-dependant sources of error, which would improve the diagnosis....... The main contribution of this work was the development of an angle estimator which features high accuracy and low standard deviation over the full 360◦ range. The estimator demonstrated its capability of operating at high frame rates (> 1000 Hz), and simultaneously detecting a large range of flow...

  10. An elusive vector dark matter

    Directory of Open Access Journals (Sweden)

    Chuan-Ren Chen

    2015-02-01

    Full Text Available Even though the sensitivity of direct dark matter search experiments reaches the level of about 10−45 cm2, no confident signal of dark matter has been observed. We point out that, if dark matter is a vector boson, the null result in direct dark matter search experiments may be due to the destructive effects in dark-matter–nucleon elastic scattering. We illustrate the scenario using a modified Higgs portal model that includes exotic quarks. The significant cancellation can occur for a certain mass gap between new heavy quark and dark matter. As a result, the spin-independent dark-matter–nucleon elastic scattering is so suppressed that the future direct search experiments will hardly observe the signal of dark matter.

  11. Differentially Private Support Vector Machines

    CERN Document Server

    Sarwate, Anand; Monteleoni, Claire

    2009-01-01

    This paper addresses the problem of practical privacy-preserving machine learning: how to detect patterns in massive, real-world databases of sensitive personal information, while maintaining the privacy of individuals. Chaudhuri and Monteleoni (2008) recently provided privacy-preserving techniques for learning linear separators via regularized logistic regression. With the goal of handling large databases that may not be linearly separable, we provide privacy-preserving support vector machine algorithms. We address general challenges left open by past work, such as how to release a kernel classifier without releasing any of the training data, and how to tune algorithm parameters in a privacy-preserving manner. We provide general, efficient algorithms for linear and nonlinear kernel SVMs, which guarantee $\\epsilon$-differential privacy, a very strong privacy definition due to Dwork et al. (2006). We also provide learning generalization guarantees. Empirical evaluations reveal promising performance on real and...

  12. A comparison of the Method of Lines to finite difference techniques in solving time-dependent partial differential equations. [with applications to Burger equation and stream function-vorticity problem

    Science.gov (United States)

    Kurtz, L. A.; Smith, R. E.; Parks, C. L.; Boney, L. R.

    1978-01-01

    Steady state solutions to two time dependent partial differential systems have been obtained by the Method of Lines (MOL) and compared to those obtained by efficient standard finite difference methods: (1) Burger's equation over a finite space domain by a forward time central space explicit method, and (2) the stream function - vorticity form of viscous incompressible fluid flow in a square cavity by an alternating direction implicit (ADI) method. The standard techniques were far more computationally efficient when applicable. In the second example, converged solutions at very high Reynolds numbers were obtained by MOL, whereas solution by ADI was either unattainable or impractical. With regard to 'set up' time, solution by MOL is an attractive alternative to techniques with complicated algorithms, as much of the programming difficulty is eliminated.

  13. Exact traveling wave solutions to the (3+1-dimensional mKdV–ZK and the (2+1-dimensional Burgers equations via exp(−Φ(η-expansion method

    Directory of Open Access Journals (Sweden)

    Md. Nur Alam

    2015-09-01

    Full Text Available In this work, the exact traveling wave solutions to the (3+1-dimensional mKdV–ZK equation and the (2+1-dimensional Burgers equation are studied using the exp(-Φ(η-expansion method. The traveling wave solutions are expressed in terms of the exponential functions, the hyperbolic functions, the trigonometric functions and the rational functions. This method is one of the powerful methods that appear in recent time in establishing some new exact traveling wave solutions to the nonlinear partial differential equations. It is shown that the exp(-Φ(η-expansion method is simple and valuable mathematical instrument for solving nonlinear evolution equations in mathematical physics and engineering.

  14. Fécula de mandioca e farinha de aveia como substitutos de gordura na formulação de hambúrguer de carne ovina Cassava starch and oatmeal as fat replacers of lamb burgers

    Directory of Open Access Journals (Sweden)

    Larissa Mont'Alverne Jucá Seabra

    2002-12-01

    acceptance in low-fat burgers. The objective of this study was to verify the effect of cassava starch and oatmeal on physical, chemical and sensory characteristics of low-fat lamb burgers. Four formulations containing lean lamb meat were tested: lean meat without added fat (F1; lean meat plus 9,15% added fat (F2; lean meat plus 2% cassava starch (F3 and lean meat plus 2% oatmeal (F4. The products were tested for chemical composition, cooking yield, shrinkage and water holding capacity, shear force, color and sensory analysis. The products with fat replacers (F3 and F4 had lower fat levels in both raw and cooked products, lower shrinkage and higher yield and water holding capacity after cooking than products without fat replacers (F1 and F2. Shear force and redness (a* value were lower in products with fat replacers (F3 and F4 as compared to those without these ingredients (F1 and F2. No differences were detected on overall acceptability of burgers from the different formulations. Thus, the use of cassava starch or oatmeal can be a good alternative for fat replacement in low-fat lamb burgers.

  15. Numerical solution of KdV-Burgers' equation by modified Bernstein polynomials and Galerkin's method%用修正Bernstein多项式Galerkin法求KdV-Burgers方程数值解

    Institute of Scientific and Technical Information of China (English)

    孙建安; 张涛锋; 陈继宇; 刘万海; 陶娜; 石玉仁

    2011-01-01

    采用修正Bernstein多项式作为基函数,使用Galerkin逼近,构造了数值求解KdV-Burgers方程的隐式格式.该格式具有很好的数值稳定性,能够有效处理长时间演化问题,数值解具有高精度.%An implicit scheme of solving numerical solution of KdV-Burgers' equation is constructed by applying modified Bernstein polynomials as basis function and Galerkin approximation. The scheme is of well numerical stability, and effective for long time evolution behavior. The numerical results are in well agreement with the exact solutions.

  16. Predicting invasion patterns in coastal ecosystems : relationship between vector strength and vector tempo

    NARCIS (Netherlands)

    Haydar, Deniz; Wolff, Wim J.

    2011-01-01

    Oyster transports are among the leading anthropogenic vectors of coastwise introduction of non-indigenous species. Using the oyster industry of the Netherlands as a model system, we investigated the relationship between vector strength (number of invasions) and vector tempo (magnitude and frequency

  17. Clustering Categories in Support Vector Machines

    DEFF Research Database (Denmark)

    Carrizosa, Emilio; Nogales-Gómez, Amaya; Morales, Dolores Romero

    2017-01-01

    The support vector machine (SVM) is a state-of-the-art method in supervised classification. In this paper the Cluster Support Vector Machine (CLSVM) methodology is proposed with the aim to increase the sparsity of the SVM classifier in the presence of categorical features, leading to a gain...

  18. Vector-Quantization using Information Theoretic Concepts

    DEFF Research Database (Denmark)

    Lehn-Schiøler, Tue; Hegde, Anant; Erdogmus, Deniz

    2005-01-01

    The process of representing a large data set with a smaller number of vectors in the best possible way, also known as vector quantization, has been intensively studied in the recent years. Very efficient algorithms like the Kohonen Self Organizing Map (SOM) and the Linde Buzo Gray (LBG) algorithm...

  19. Clifford Fourier transform on vector fields.

    Science.gov (United States)

    Ebling, Julia; Scheuermann, Gerik

    2005-01-01

    Image processing and computer vision have robust methods for feature extraction and the computation of derivatives of scalar fields. Furthermore, interpolation and the effects of applying a filter can be analyzed in detail and can be advantages when applying these methods to vector fields to obtain a solid theoretical basis for feature extraction. We recently introduced the Clifford convolution, which is an extension of the classical convolution on scalar fields and provides a unified notation for the convolution of scalar and vector fields. It has attractive geometric properties that allow pattern matching on vector fields. In image processing, the convolution and the Fourier transform operators are closely related by the convolution theorem and, in this paper, we extend the Fourier transform to include general elements of Clifford Algebra, called multivectors, including scalars and vectors. The resulting convolution and derivative theorems are extensions of those for convolution and the Fourier transform on scalar fields. The Clifford Fourier transform allows a frequency analysis of vector fields and the behavior of vector-valued filters. In frequency space, vectors are transformed into general multivectors of the Clifford Algebra. Many basic vector-valued patterns, such as source, sink, saddle points, and potential vortices, can be described by a few multivectors in frequency space.

  20. Application of Vectors to Relative Velocity

    Science.gov (United States)

    Tin-Lam, Toh

    2004-01-01

    The topic 'relative velocity' has recently been introduced into the Cambridge Ordinary Level Additional Mathematics syllabus under the application of Vectors. In this note, the results of relative velocity and the 'reduction to rest' technique of teaching relative velocity are derived mathematically from vector algebra, in the hope of providing…

  1. Articulated Multimedia Physics, Lesson 4, Vectors.

    Science.gov (United States)

    New York Inst. of Tech., Old Westbury.

    As the fourth lesson of the Articulated Multimedia Physics Course, instructional materials are presented in this study guide. The subject matter is concerned with displacements, speeds, scalers, vector sum, and vector analysis.The content is arranged in scrambled form, and the use of matrix transparencies is required for students to control their…

  2. Diffeomorphism Invariant Theories and Vector Supersymmetry

    CERN Document Server

    Piguet, O

    2000-01-01

    Einstein gravity in the Palatini first order formalism is shown to possess a vector supersymmetry of the type encountered in the topological gauge theories. A peculiar feature of the gravitationel theory is the link of this vector supersymmetry with the field equation of motion of the Faddeev-Popov ghost associated to diffeomorphism invariance.

  3. Deep Support Vector Machines for Regression Problems

    NARCIS (Netherlands)

    Wiering, Marco; Schutten, Marten; Millea, Adrian; Meijster, Arnold; Schomaker, Lambertus

    2013-01-01

    In this paper we describe a novel extension of the support vector machine, called the deep support vector machine (DSVM). The original SVM has a single layer with kernel functions and is therefore a shallow model. The DSVM can use an arbitrary number of layers, in which lower-level layers contain su

  4. Increasing the Efficacy of Oncolytic Adenovirus Vectors

    Directory of Open Access Journals (Sweden)

    William S. M. Wold

    2010-08-01

    Full Text Available Oncolytic adenovirus (Ad vectors present a new modality to treat cancer. These vectors attack tumors via replicating in and killing cancer cells. Upon completion of the vector replication cycle, the infected tumor cell lyses and releases progeny virions that are capable of infecting neighboring tumor cells. Repeated cycles of vector replication and cell lysis can destroy the tumor. Numerous Ad vectors have been generated and tested, some of them reaching human clinical trials. In 2005, the first oncolytic Ad was approved for the treatment of head-and-neck cancer by the Chinese FDA. Oncolytic Ads have been proven to be safe, with no serious adverse effects reported even when high doses of the vector were injected intravenously. The vectors demonstrated modest anti-tumor effect when applied as a single agent; their efficacy improved when they were combined with another modality. The efficacy of oncolytic Ads can be improved using various approaches, including vector design, delivery techniques, and ancillary treatment, which will be discussed in this review.

  5. Nonlinear dynamics of a vectored thrust aircraft

    DEFF Research Database (Denmark)

    Sørensen, C.B; Mosekilde, Erik

    1996-01-01

    With realistic relations for the aerodynamic coefficients, numerical simulations are applied to study the longitudional dynamics of a thrust vectored aircraft. As function of the thrust magnitude and the thrust vectoring angle the equilibrium state exhibits two saddle-node bifurcations and three ...

  6. Chiral Corrections to Vector Meson Decay Constants

    CERN Document Server

    Bijnens, J; Talavera, P; Bijnens, Johan; Gosdzinsky, Peter; Talavera, Pere

    1998-01-01

    We calculate the leading quark mass corrections of order $m_q\\log(m_q)$, $m_q$ and $m_q^{3/2}$ to the vector meson decay constants within Heavy Vector Meson Chiral Perturbation Theory. We discuss the issue of electromagnetic gauge invariance and the heavy mass expansion. Reasonably good fits to the observed decay constants are obtained.

  7. CLASSIFICATION OF CUBIC PARAMETERIZED HOMOGENEOUS VECTOR FIELDS

    Institute of Scientific and Technical Information of China (English)

    Karnal H.Yasir; TANG Yun

    2002-01-01

    In this paper the cubic homogeneous parameterized vector fields are studied.The classification of the phase portrait near the critical point is presented. This classification is an extension of the result given by Takens to the cubic homogeneous parameterized vector fields with six parameters.

  8. CLASSIFICATION OF CUBIC PARAMETERIZED HOMOGENEOUS VECTOR FIELDS

    Institute of Scientific and Technical Information of China (English)

    KamalH.Yasir; TNAGYun

    2002-01-01

    In this paper the cubic homogeneous parameterized vector fields are studied.The classification of the phase portrait near the critical point is presented.This classification is an extension of the result given by takens to the cubic homogeneous parameterized vector fields with six parameters.

  9. 40 CFR 240.206 - Vectors.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Vectors. 240.206 Section 240.206 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.206 Vectors....

  10. Vector Spaces of Non-measurable Functions

    Institute of Scientific and Technical Information of China (English)

    Francisco J. GARC(I)A-PACHECO; Juan B. SEOANE-SEP(U)LVEDA

    2006-01-01

    We show that there exists an infinite dimensional vector space every non-zero element of which is a non-measurable function. Moreover, this vector space can be chosen to be closed and to have dimensionβ for any cardinalityβ. Some techniques involving measure theory and density characters of Banach spaces are used.

  11. A Survey on Distance Vector Routing Protocols

    CERN Document Server

    Tang, Linpeng

    2011-01-01

    In this paper we give a brief introduction to five different distance vector routing protocols (RIP, AODV, EIGRP, RIP-MTI and Babel) and give some of our thoughts on how to solve the count to infinity problem. Our focus is how distance vector routing protocols, based on limited information, can prevent routing loops and the count to infinity problem.

  12. Cascade Support Vector Machines with Dimensionality Reduction

    Directory of Open Access Journals (Sweden)

    Oliver Kramer

    2015-01-01

    Full Text Available Cascade support vector machines have been introduced as extension of classic support vector machines that allow a fast training on large data sets. In this work, we combine cascade support vector machines with dimensionality reduction based preprocessing. The cascade principle allows fast learning based on the division of the training set into subsets and the union of cascade learning results based on support vectors in each cascade level. The combination with dimensionality reduction as preprocessing results in a significant speedup, often without loss of classifier accuracies, while considering the high-dimensional pendants of the low-dimensional support vectors in each new cascade level. We analyze and compare various instantiations of dimensionality reduction preprocessing and cascade SVMs with principal component analysis, locally linear embedding, and isometric mapping. The experimental analysis on various artificial and real-world benchmark problems includes various cascade specific parameters like intermediate training set sizes and dimensionalities.

  13. Alphavirus vectors for cancer gene therapy (review).

    Science.gov (United States)

    Yamanaka, Ryuya

    2004-04-01

    Alphaviruses have several characteristics that make them attractive as gene therapy vectors such as transient and high-level expression of a heterologous gene. Alphavirus vectors, Semliki Forest virus (SFV), Sindbis virus (SIN) and Venezuelan equine encephalitis virus (VEE) have been developed as gene expression vectors. Alphaviruses are positive-strand RNA viruses that can mediate efficient cytoplasmic gene expression in mammalian cells. The alphavirus RNA replication machinery has been engineered for high level heterologous gene expression. Since an RNA virus vector cannot integrate into chromosomal DNA, concerns about cell transformation are reduced. Alphavirus vectors demonstrate promise for the safe tumor-killing and tumor-specific immune responses. Recombinant alphavirus RNA replicons may facilitate gene therapy of cancer.

  14. Vector Diffusion Maps and the Connection Laplacian

    CERN Document Server

    Singer, Amit

    2011-01-01

    We introduce {\\em vector diffusion maps} (VDM), a new mathematical framework for organizing and analyzing massive high dimensional data sets, images and shapes. VDM is a mathematical and algorithmic generalization of diffusion maps and other non-linear dimensionality reduction methods, such as LLE, ISOMAP and Laplacian eigenmaps. While existing methods are either directly or indirectly related to the heat kernel for functions over the data, VDM is based on the heat kernel for vector fields. VDM provides tools for organizing complex data sets, embedding them in a low dimensional space, and interpolating and regressing vector fields over the data. In particular, it equips the data with a metric, which we refer to as the {\\em vector diffusion distance}. In the manifold learning setup, where the data set is distributed on (or near) a low dimensional manifold $\\MM^d$ embedded in $\\RR^{p}$, we prove the relation between VDM and the connection-Laplacian operator for vector fields over the manifold.

  15. Axial Vector $Z'$ and Anomaly Cancellation

    CERN Document Server

    Ismail, Ahmed; Tsao, Kuo-Hsing; Unwin, James

    2016-01-01

    Whilst the prospect of new $Z'$ gauge bosons with only axial couplings to the Standard Model (SM) fermions is widely discussed, examples of anomaly-free renormalisable models are lacking in the literature. We look to remedy this by constructing several motivated examples. Specifically, we consider axial vectors which couple universally to all SM fermions, as well as those which are generation-specific, leptophilic, and leptophobic. Anomaly cancellation typically requires the presence of new coloured and charged chiral fermions, and we argue that the masses of these new states must generally be comparable to that of the axial vector. Finally, an axial vector mediator could provide a portal between SM and hidden sector states, and we also consider the possibility that the axial vector couples to dark matter. If the dark matter relic density is set due to freeze-out via the axial vector, this strongly constrains the parameter space.

  16. Low-amplitude vector screening solitons

    Institute of Scientific and Technical Information of China (English)

    Keqing Lu(卢克清); Xiangping Zhu(朱香平); Wei Zhao(赵卫); Yanlong Yang(杨延龙); Jinping Li(李金萍); Yanpeng Zhang(张彦鹏); Junchang Zhang(张君昌)

    2004-01-01

    We show self-coupled and cross-coupled vector beam evolution equations in the low-amplitude regime for screening solitons,which can exhibit the analytical solutions of bright-bright and dark-dark vector solitons.Our analysis indicates that these self-coupled vector solitons are obtained irrespective of the intensities of the two optical beams,whereas these cross-coupled vector solitons can be established when the intensities of the two optical beams are equal.Relevant examples are provided where the photorefractive crystal is lithium niobate(LiNbO3).The stability properties of these vector solitons have been investigated numerically and it has been found that they are stable.

  17. Gauge vectors and double beta decay

    Science.gov (United States)

    Fonseca, Renato M.; Hirsch, Martin

    2017-02-01

    We discuss contributions to neutrinoless double beta (0 ν β β ) decay involving vector bosons. The starting point is a list of all possible vector representations that may contribute to 0 ν β β decay via d =9 or d =11 operators at tree level. We then identify gauge groups which contain these vectors in the adjoint representation. Even though the complete list of vector fields that can contribute to 0 ν β β up to d =11 is large (a total of 46 vectors), only a few of them can be gauge bosons of phenomenologically realistic groups. These latter cases are discussed in some more detail, and lower (upper) limits on gauge boson masses (mixing angles) are derived from the absence of 0 ν β β decay.

  18. Geoacoustic inversion using the vector field

    Science.gov (United States)

    Crocker, Steven E.

    The main goal of this project was to study the use of the acoustic vector field, separately or in combination with the scalar field, to estimate the depth dependent geoacoustic properties of the seafloor via non-linear inversion. The study was performed in the context of the Sediment Acoustics Experiment 2004 (SAX04) conducted in the Northern Gulf of Mexico (GOM) where a small number of acoustic vector sensors were deployed in close proximity to the seafloor. A variety of acoustic waveforms were transmitted into the seafloor at normal incidence. The acoustic vector sensors were located both above and beneath the seafloor interface where they measured the acoustic pressure and the acoustic particle acceleration. Motion data provided by the buried vector sensors were affected by a suspension response that was sensitive to the mass properties of the sensor, the sediment density and sediment elasticity (e.g., shear wave speed). The suspension response for the buried vector sensors included a resonance within the analysis band of 0.4 to 2.0 kHz. The suspension resonance represented an unknown complex transfer function between the acoustic vector field in the seabed and data representing that field. Therefore, inverse methods developed for this study were required to 1) estimate dynamic properties of the sensor suspension resonance and 2) account for the associated corruption of vector field data. A method to account for the vector sensor suspense response function was integrated directly into the inversion methods such that vector channel data corruption was reduced and an estimate of the shear wave speed in the sediment was returned. Inversions of real and synthetic data sets indicated that information about sediment shear wave speed was carried by the suspension response of the buried sensors, as opposed to being contained inherently within the acoustic vector field.

  19. Image Coding Based on Address Vector Quantization.

    Science.gov (United States)

    Feng, Yushu

    Image coding is finding increased application in teleconferencing, archiving, and remote sensing. This thesis investigates the potential of Vector Quantization (VQ), a relatively new source coding technique, for compression of monochromatic and color images. Extensions of the Vector Quantization technique to the Address Vector Quantization method have been investigated. In Vector Quantization, the image data to be encoded are first processed to yield a set of vectors. A codeword from the codebook which best matches the input image vector is then selected. Compression is achieved by replacing the image vector with the index of the code-word which produced the best match, the index is sent to the channel. Reconstruction of the image is done by using a table lookup technique, where the label is simply used as an address for a table containing the representative vectors. A code-book of representative vectors (codewords) is generated using an iterative clustering algorithm such as K-means, or the generalized Lloyd algorithm. A review of different Vector Quantization techniques are given in chapter 1. Chapter 2 gives an overview of codebook design methods including the Kohonen neural network to design codebook. During the encoding process, the correlation of the address is considered and Address Vector Quantization is developed for color image and monochrome image coding. Address VQ which includes static and dynamic processes is introduced in chapter 3. In order to overcome the problems in Hierarchical VQ, Multi-layer Address Vector Quantization is proposed in chapter 4. This approach gives the same performance as that of the normal VQ scheme but the bit rate is about 1/2 to 1/3 as that of the normal VQ method. In chapter 5, a Dynamic Finite State VQ based on a probability transition matrix to select the best subcodebook to encode the image is developed. In chapter 6, a new adaptive vector quantization scheme, suitable for color video coding, called "A Self -Organizing

  20. The Representation of a Broadband Vector Field

    Institute of Scientific and Technical Information of China (English)

    Qunyan Ren; Jean Pierre Hermand; Shengchun Piao

    2011-01-01

    Compared to a scalar pressure sensor,a vector sensor can provide a higher signal-to-noise ratio (SNR)signal and more detailed information on the sound field.Study on vector sensors and their applications have become a hot topic.Research on the representation of a vector field is highly relevant for extending the scope of vector sensor technology.This paper discusses the range-frequency distribution of the vector field due to a broadband acoustic source moving in a shallow-water waveguide as the self noise of a surface ship,and the vector extension of the waveguide impulse response measured over a limited frequency range using an active source of known waveform.From theory analysis and numerical simulation,the range-frequency representation of a vector field exhibits an interference structure qualitatively similar to that of the corresponding pressure field but,being quantitatively different,provides additional information on the waveguide,especially through the vertical component.For the range-frequency representation,physical quantities that can better exhibit the interference characteristics of the waveguide are the products of pressure and particle velocity and of the pressure and pressure gradient.An image processing method to effectively detect and isolate the individual striations from an interference structure was reviewed briefly.The representation of the vector impulse response was discussed according to two different measurement systems,also known as particle velocity and pressure gradient.The vector impulse response representation can not only provide additional information from pressure only but even more than that of the range-frequency representation.

  1. Efficient than a Nonlentiviral Vector

    Directory of Open Access Journals (Sweden)

    Tao Yang

    2010-01-01

    Full Text Available Background. Lentiviral constructs reportedly can integrate into the genome of non-dividing, terminally differentiated cells and dividing cells, for long-term gene expression. This investigation tested whether a third generation lentiviral-mediated small interfering RNA (siRNA delivered into renal epithelial and fibroblast cells against type II transforming growth factor-beta receptor (siRNA-TBRII could better attenuate renal fibrogenesis in comparison with a non-lentiviral construct. Methods. HIV-derived lentiviral and non-lentiviral constructs were used to transfect cells with siRNA-TBRII or siRNA-EGFP control. Human embryonic kidney (HEK-293T, renal epithelial cells (NRK-52E and renal fibroblasts (NRK-49F were transfected and gene silencing quantified (fluorescence microscopy, Western blotting, fluorescence-activated cell sorting. Renal fibrogenesis was assessed using extracellular matrix protein synthesis (fibronectin and collagen-III; Western immunoblot, and α-smooth muscle actin (α-SMA was analysed as a marker of fibroblast activation and epithelial-to-mesenchymal transdifferentiation (EMT. Results. Lentiviral-mediated siRNA-TBRII significantly suppressed TBRII expression in all cell lines, and also significantly suppressed renal fibrogenesis. In comparison with the non-lentiviral construct, lentiviral-mediated siRNA-TBRII produced stronger and more persistent inhibition of collagen-III in NRK-49F cells, fibronectin in all renal cell lines, and α-SMA in renal epithelial cells. Conclusions. Lentiviral vector systems against TBRII can be delivered into renal cells to efficiently limit renal fibrogenesis by sequence-specific gene silencing.

  2. New Anomaly of the Axial-Vector Current

    Institute of Scientific and Technical Information of China (English)

    HE Han-Xin

    2001-01-01

    By computing the axial-vector current operator equation, we find the anomalous axial-vector curl equation besides the well-known anomalous axial-vector divergence equation (the Adler-Bell-Jackiw anomaly) and discuss its implication.``

  3. A NEW HYPERSPHERE SUPPORT VECTOR MACHINE ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    Zhang Xinfeng; Shen Lansun

    2006-01-01

    The hypersphere support vector machine is a new algorithm in pattern recognition. By studying three kinds ofhypersphere support vector machines, it is found that their solutions are identical and the margin between two classes of samples is zero or is not unique. In this letter, a new kind ofhypersphere support vector machine is proposed. By introducing a parameter n(n>l), a unique solution of the margin can be obtained.Theoretical analysis and experimental results show that the proposed algorithm can achieve better generalization performance.

  4. Nonlinear singular vectors and nonlinear singular values

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel concept of nonlinear singular vector and nonlinear singular value is introduced, which is a natural generalization of the classical linear singular vector and linear singular value to the nonlinear category. The optimization problem related to the determination of nonlinear singular vectors and singular values is formulated. The general idea of this approach is demonstrated by a simple two-dimensional quasigeostrophic model in the atmospheric and oceanic sciences. The advantage and its applications of the new method to the predictability, ensemble forecast and finite-time nonlinear instability are discussed. This paper makes a necessary preparation for further theoretical and numerical investigations.

  5. Robust Pseudo-Hierarchical Support Vector Clustering

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Sjöstrand, Karl; Olafsdóttir, Hildur

    2007-01-01

    Support vector clustering (SVC) has proven an efficient algorithm for clustering of noisy and high-dimensional data sets, with applications within many fields of research. An inherent problem, however, has been setting the parameters of the SVC algorithm. Using the recent emergence of a method...... for calculating the entire regularization path of the support vector domain description, we propose a fast method for robust pseudo-hierarchical support vector clustering (HSVC). The method is demonstrated to work well on generated data, as well as for detecting ischemic segments from multidimensional myocardial...

  6. Meromorphic Vector Fields and Circle Packings

    DEFF Research Database (Denmark)

    Dias, Kealey

    of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions or meromorphic (allowing poles...... as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic vector fields. Restricting...

  7. 600-GHz Electronically Tunable Vector Measurement System

    Science.gov (United States)

    Dengler, Robert; Maiwald, Frank; Siegel, Peter

    2007-01-01

    A compact, high-dynamic-range, electronically tunable vector measurement system that operates in the frequency range from approximately 560 to approximately 635 GHz has been developed as a prototype of vector measurement systems that would be suitable for use in nearly-real-time active submillimeter-wave imaging. As used here, 'vector measurement system" signifies an instrumentation system that applies a radio-frequency (RF) excitation to an object of interest and measures the resulting amplitude and phase response, relative to either the applied excitatory signal or another reference signal related in a known way to applied excitatory signal.

  8. Neural net approach to predictive vector quantization

    Science.gov (United States)

    Mohsenian, Nader; Nasrabadi, Nasser M.

    1992-11-01

    A new predictive vector quantization (PVQ) technique, capable of exploring the nonlinear dependencies in addition to the linear dependencies that exist between adjacent blocks of pixels, is introduced. Two different classes of neural nets form the components of the PVQ scheme. A multi-layer perceptron is embedded in the predictive component of the compression system. This neural network, using the non-linearity condition associated with its processing units, can perform as a non-linear vector predictor. The second component of the PVQ scheme vector quantizes (VQ) the residual vector that is formed by subtracting the output of the perceptron from the original wave-pattern. Kohonen Self-Organizing Feature Map (KSOFM) was utilized as a neural network clustering algorithm to design the codebook for the VQ technique. Coding results are presented for monochrome 'still' images.

  9. Twisted Vector Bundles on Pointed Nodal Curves

    Indian Academy of Sciences (India)

    Ivan Kausz

    2005-05-01

    Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich’s and Vistoli’s twisted bundles and Gieseker vector bundles.

  10. Sensorless vector and direct torque control

    CERN Document Server

    Vas, Peter

    1998-01-01

    This is the first comprehensive book on sensorless high performance a.c. drives. It is essential reading for anyone interested in acquiring a solid background on sensorless torque-controlled drives. It presents a detailed and unified treatment of sensorless vector-controlled and direct-torque controlled drive systems. It also discusses the applications of artificial intelligence to drives. Where possible, space vector theory is used and emphasis is laid on detailed mathematical and physical analysis. Sensorless drive schemes for different types of permanent magnet synchronous motors, synchronous reluctance motors, and induction motors are also presented. These include more than twenty vector drives e.g. five types of MRAS-based vector drives, and eleven types of direct-torque-controlled (DTC) drives, e.g. the ABB DTC drive. However, torque-controlled switched reluctance motor drives are also discussed due to their emerging importance. The book also covers various drive applications using artificial intellige...

  11. Vector Potential Generation for Numerical Relativity Simulations

    Science.gov (United States)

    Silberman, Zachary; Faber, Joshua; Adams, Thomas; Etienne, Zachariah; Ruchlin, Ian

    2017-01-01

    Many different numerical codes are employed in studies of highly relativistic magnetized accretion flows around black holes. Based on the formalisms each uses, some codes evolve the magnetic field vector B, while others evolve the magnetic vector potential A, the two being related by the curl: B=curl(A). Here, we discuss how to generate vector potentials corresponding to specified magnetic fields on staggered grids, a surprisingly difficult task on finite cubic domains. The code we have developed solves this problem in two ways: a brute-force method, whose scaling is nearly linear in the number of grid cells, and a direct linear algebra approach. We discuss the success both algorithms have in generating smooth vector potential configurations and how both may be extended to more complicated cases involving multiple mesh-refinement levels. NSF ACI-1550436

  12. Integrated epidemiology for vector-borne zoonoses.

    Science.gov (United States)

    Wardrop, Nicola A

    2016-02-01

    The development and application of interventions for the control of vector-borne zoonoses requires broad understanding of epidemiological linkages between vector, animal infection and human infection. However, there are significant gaps in our understanding of these linkages and a lack of appropriate data poses a considerable barrier to addressing this issue. A move towards strengthened surveillance of vectors and disease in both animal and human hosts, in combination with linked human-animal surveys, could form the backbone for epidemiological integration, enabling explicit assessment of the animal-human (and vector) interface, and subsequent implications for spill-over to human populations. Currently available data on the spatial distribution of human African trypanosomiasis allow an illustrative example.

  13. Triangle Lattice Green Functions for Vector Fields

    Science.gov (United States)

    Moritz, Brian; Schwalm, William

    2000-03-01

    The triangle lattice is convenient for modeling fields and fluid flows in two dimensions. Discrete vector field equations are defined through the analogy between differential forms and simplicial homology theory. The basic vector difference operators on the lattice correspond to the graph adjacency matricies of the triangle, honeycomb, and Kagomé lattices. The scalar Green functions for nearest neighbor interactions on the triangle lattice are known in closed form in terms of the complete elliptic integrals. Green functions for vector field operators are obtained explicitly in terms of the known scalar Green functions. The scalar Green functions for the Kagomé lattice are thus written in terms of the Green functions for the triangle lattice and ultimately in closed form. Thus, Green functions for a wide range of vector difference models are reduced to closed form in terms of the complete elliptic integrals.

  14. Low Power, Self Calibrated Vector Magnetometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR project investigates a novel approach to vector magnetometry based on high precision measurements of the total magnetic field. The calibration is...

  15. Small automorphic representations and degenerate Whittaker vectors

    CERN Document Server

    Gustafsson, Henrik P A; Persson, Daniel

    2014-01-01

    We investigate Fourier coefficients of automorphic forms on split simply-laced Lie groups G. We show that for automorphic representations of small Gelfand-Kirillov dimension the Fourier coefficients are completely determined by certain degenerate Whittaker vectors on G. Although we expect our results to hold for arbitrary simply-laced groups, we give complete proofs only for G=SL(3) and G=SL(4). This is based on a method of Ginzburg that associates Fourier coefficients of automorphic forms with nilpotent orbits of G. Our results complement and extend recent results of Miller and Sahi. We also use our formalism to calculate various local (real and p-adic) spherical vectors of minimal representations of the exceptional groups E_6, E_7, E_8 using global (adelic) degenerate Whittaker vectors, correctly reproducing existing results for such spherical vectors obtained by very different methods.

  16. Insects as vectors: systematics and biology.

    Science.gov (United States)

    Rodhain, F

    2015-04-01

    Among the many complex relationships between insects and microorganisms such as viruses, bacteria and parasites, some have resulted in the establishment of biological systems within which the insects act as a biological vector for infectious agents. It is therefore advisable to understand the identity and biology of these vectors in depth, in order to define procedures for epidemiological surveillance and anti-vector control. The following are successively reviewed in this article: Anoplura (lice), Siphonaptera (fleas), Heteroptera (bugs: Cimicidae, Triatoma, Belostomatidae), Psychodidae (sandflies), Simuliidae (black flies), Ceratopogonidae (biting midges), Culicidae (mosquitoes), Tabanidae (horseflies) and Muscidae (tsetse flies, stable flies and pupipara). The authors provide a rapid overview of the morphology, systematics, development cycle and bio-ecology of each of these groups of vectors. Finally, their medical and veterinary importance is briefly reviewed.

  17. Gamow vectors explain the shock profile.

    Science.gov (United States)

    Braidotti, Maria Chiara; Gentilini, Silvia; Conti, Claudio

    2016-09-19

    The description of shock waves beyond the shock point is a challenge in nonlinear physics and optics. Finding solutions to the global dynamics of dispersive shock waves is not always possible due to the lack of integrability. Here we propose a new method based on the eigenstates (Gamow vectors) of a reversed harmonic oscillator in a rigged Hilbert space. These vectors allow analytical formulation for the development of undular bores of shock waves in a nonlinear nonlocal medium. Experiments by a photothermal induced nonlinearity confirm theoretical predictions: the undulation period as a function of power and the characteristic quantized decays of Gamow vectors. Our results demonstrate that Gamow vectors are a novel and effective paradigm for describing extreme nonlinear phenomena.

  18. Gamow Vectors Explain the Shock "Batman" Profile

    CERN Document Server

    Braidotti, Maria Chiara; Conti, Claudio

    2016-01-01

    The description of shock waves beyond the shock point is a challenge in nonlinear physics. Finding solutions to the global dynamics of dispersive shock waves is not always possible due to the lack of integrability. Here we propose a new method based on the eigenstates (Gamow vectors) of a reversed harmonic oscillator in a rigged Hilbert space. These vectors allow analytical formulation for the development of undular bores of shock waves in a nonlinear nonlocal medium. Experiments by a photothermal induced nonlinearity confirm theoretical predictions: as the undulation period as a function of power and the characteristic quantized decays of Gamow vectors. Our results demonstrate that Gamow vector are a novel and effective paradigm for describing extreme nonlinear phenomena.

  19. Weaving knotted vector fields with tunable helicity

    CERN Document Server

    Kedia, Hridesh; Dennis, Mark R; Irvine, William T M

    2016-01-01

    We present a general construction of divergence-free knotted vector fields from complex scalar fields, whose closed field lines encode many kinds of knots and links, including torus knots, their cables, the figure-8 knot and its generalizations. As finite-energy physical fields they represent initial states for fields such as the magnetic field in a plasma, or the vorticity field in a fluid. We give a systematic procedure for calculating the vector potential, starting from complex scalar functions with knotted zero filaments, thus enabling an explicit computation of the helicity of these knotted fields. The construction can be used to generate isolated knotted flux tubes, filled by knots encoded in the lines of the vector field. Lastly we give examples of manifestly knotted vector fields with vanishing helicity. Our results provide building blocks for analytical models and simulations alike.

  20. Generalized Stokes vector for three photon process

    CERN Document Server

    Shaji, Chitra; Satyanarayana, SVM; Sharan, Alok

    2015-01-01

    Stokes Muller formalism is important to understand the optical properties of materials by measuring the change in the polarization state of light upon scattering. The formalism can be extended to nonlinear scattering processes involving two and three photon processes. In this work, we derive a triple Stokes vector analytically using operator approach used in quantum theory of light. A three photon polarization state can be described by Stokes vector that has sixteen components involving cubes of intensities. The response of a material for the scattering of light in a three photon process is described by 4 x 16 Muller matrix. Polarization in Polarization out (PIPO) experiments can be carried out to determine the elements of Muller matrix. For that we identify 16 independent points in Poincare sphere and construct triple Stokes vector for each point. Four measurements to find the linear Stokes vector of the scattered light for incident light in each of the sixteen three photon states determine the Muller matrix...

  1. The light filament as vector solitary wave

    CERN Document Server

    Kovachev, Lubomir M

    2015-01-01

    We present an analytical approach to the theory of nonlinear propagation of femtosecond optical pulses with broad-band spectrum in gases. The vector character of the nonlinear third-order polarization is investigated in details, taking into account the carrier to envelope phase. The corresponding system of vector amplitude equations is written by using left-hand and right-hand circular components of the electrical field. We found that this system nonlinear equations admits $3D+1$ vector soliton solution with Lorentz shape. The solution presents relatively stable propagation and rotation with GHz frequency of the vector of the electrical field in plane, orthogonal to the direction of propagation. The evolution of the intensity profile demonstrate weak self-compression and week spherical wave in the first milliseconds of propagation.

  2. Ontology for vector surveillance and management.

    Science.gov (United States)

    Lozano-Fuentes, Saul; Bandyopadhyay, Aritra; Cowell, Lindsay G; Goldfain, Albert; Eisen, Lars

    2013-01-01

    Ontologies, which are made up by standardized and defined controlled vocabulary terms and their interrelationships, are comprehensive and readily searchable repositories for knowledge in a given domain. The Open Biomedical Ontologies (OBO) Foundry was initiated in 2001 with the aims of becoming an "umbrella" for life-science ontologies and promoting the use of ontology development best practices. A software application (OBO-Edit; *.obo file format) was developed to facilitate ontology development and editing. The OBO Foundry now comprises over 100 ontologies and candidate ontologies, including the NCBI organismal classification ontology (NCBITaxon), the Mosquito Insecticide Resistance Ontology (MIRO), the Infectious Disease Ontology (IDO), the IDOMAL malaria ontology, and ontologies for mosquito gross anatomy and tick gross anatomy. We previously developed a disease data management system for dengue and malaria control programs, which incorporated a set of information trees built upon ontological principles, including a "term tree" to promote the use of standardized terms. In the course of doing so, we realized that there were substantial gaps in existing ontologies with regards to concepts, processes, and, especially, physical entities (e.g., vector species, pathogen species, and vector surveillance and management equipment) in the domain of surveillance and management of vectors and vector-borne pathogens. We therefore produced an ontology for vector surveillance and management, focusing on arthropod vectors and vector-borne pathogens with relevance to humans or domestic animals, and with special emphasis on content to support operational activities through inclusion in databases, data management systems, or decision support systems. The Vector Surveillance and Management Ontology (VSMO) includes >2,200 unique terms, of which the vast majority (>80%) were newly generated during the development of this ontology. One core feature of the VSMO is the linkage, through

  3. Influence of natural antioxidants on lipid composition of beef burgers submitted to irradiation in {sup 60} Co source and electron beams; Influencia de antioxidantes naturais sobre o perfil lipidico de hamburgueres bovinos submetidos a irradiacao por {sup 60}Co e aceleradores de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Reginaldo Almeida da

    2007-07-01

    Radiation processing has been employed in some countries as a mean of treatment to assure microbiological safety of meat and meat products, avoiding the occurrence of food-borne disease. The ionizing radiation may cause some undesirable changes on chemistry composition of food and the lipid oxidation is one of the main reactions. In meat products processing industry, the lipid composition is directly related to nutritional and sensory quality of the product. For preventing oxidation, use of antioxidants which can be synthetic or natural, has been practically applied in some products. Currently, most attention has been given to natural antioxidants from herbs and spices like rosemary and oregano. The aim this study was to assess the antioxidant effects of either rosemary and oregano extract in beef burgers submitted to irradiation in {sup 60}Co source with dose 6, 7 e 8 kGy, electron beams with dose 3,5 e 7 kGy and storage under freeze along 0, 45 e 90 days. The results showed that rosemary extract has the major antioxidant effects when it is used on heterogeneous food matrix like beef burger, but oregano extract was better efficient to delay lipid oxidation along storage time when it is used in synergism with rosemary and/or BHT/BHA. Although to have occurred changes in the fatty acids composition it was not possible to demonstrate a straight dependence of irradiation dose and/or storage time. Sensory analysis showed that between the samples prepared with natural antioxidants, the beef burger prepared with oregano has received better scores by panelists. Irradiated beef burger prepared with rosemary has received better scores when compared to non-irradiated one. The use of spices with antioxidant activity to avoid the oxidative damage in foods that contain fats in their formulation is thought to be promising to application in food facilities. (author)

  4. New approach to training support vector machine

    Institute of Scientific and Technical Information of China (English)

    Tang Faming; Chen Mianyun; Wang Zhongdong

    2006-01-01

    Support vector machine has become an increasingly popular tool for machine learning tasks involving classification, regression or novelty detection. Training a support vector machine requires the solution of a very large quadratic programming problem. Traditional optimization methods cannot be directly applied due to memory restrictions. Up to now, several approaches exist for circumventing the above shortcomings and work well. Another learning algorithm, particle swarm optimization, for training SVM is introduted. The method is tested on UCI datasets.

  5. Visualization of Vector Field by Virtual Reality

    Science.gov (United States)

    Kageyama, A.; Tamura, Y.; Sato, T.

    A visualization software program is developed in order to analyze three dimensional vector fields by means of today's advanced virtual reality technology. This program enables simulation researchers to interactively visualize stream lines, tracer particle motions, isosurfaces, etc.~with stereo view. The program accepts any kind of vector fields on structured mesh as an input data. A virtual reality hardware system, on which the program operates, and details of the program are described.

  6. Killing vector fields and harmonic superfield theories

    Energy Technology Data Exchange (ETDEWEB)

    Groeger, Josua, E-mail: groegerj@mathematik.hu-berlin.de [Humboldt-Universität zu Berlin, Institut für Mathematik, Rudower Chaussee 25, 12489 Berlin (Germany)

    2014-09-15

    The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

  7. Killing Vector Fields and Superharmonic Field Theories

    CERN Document Server

    Groeger, Josua

    2013-01-01

    The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, referred to as superharmonic action, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of the superharmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

  8. Dynamics of localized structures in vector waves

    CERN Document Server

    Hernández-García, E; Colet, P; San Miguel, M; Hernandez-Garcia, Emilio; Hoyuelos, Miguel; Colet, Pere; Miguel, Maxi San

    1999-01-01

    Dynamical properties of topological defects in a twodimensional complex vector field are considered. These objects naturally arise in the study of polarized transverse light waves. Dynamics is modeled by a Vector Complex Ginzburg-Landau Equation with parameter values appropriate for linearly polarized laser emission. Creation and annihilation processes, and selforganization of defects in lattice structures, are described. We find "glassy" configurations dominated by vectorial defects and a melting process associated to topological-charge unbinding.

  9. Solving Parity Games on Integer Vectors

    OpenAIRE

    Abdulla, Parosh Aziz; Mayr, Richard; Sangnier, Arnaud; Sproston, Jeremy

    2013-01-01

    We consider parity games on infinite graphs where configurations are represented by control-states and integer vectors. This framework subsumes two classic game problems: parity games on vector addition systems with states (vass) and multidimensional energy parity games. We show that the multidimensional energy parity game problem is inter-reducible with a subclass of single-sided parity games on vass where just one player can modify the integer counters and the opponent can only change contr...

  10. Vector database for vehicle road navigation

    OpenAIRE

    Kenda, Lian

    2007-01-01

    Vehicle navigation devices use vector cartographic view, which is designed as a vector database. Database creation begins by setting up a landscape model which includes all the graphical and descriptive data required for accurate vehicle navigation. This paper presents the creation of a database part called StreetConnect, which is used for road navigation. Data obtained using distinct specifications have been transformed into the format compatible with Garmin GPS devices. Data have been obtai...

  11. Vector field processing on triangle meshes

    OpenAIRE

    De Goes, Fernando; Desbrun, Mathieu; Tong, Yiying

    2015-01-01

    While scalar fields on surfaces have been staples of geometry processing, the use of tangent vector fields has steadily grown in geometry processing over the last two decades: they are crucial to encoding directions and sizing on surfaces as commonly required in tasks such as texture synthesis, non-photorealistic rendering, digital grooming, and meshing. There are, however, a variety of discrete representations of tangent vector fields on triangle meshes, and each approach offers different tr...

  12. Improvised microinjection technique for mosquito vectors

    OpenAIRE

    Sampath, Kumar S.; H.P.Puttaraju

    2012-01-01

    Background & objectives: Bio-manipulation technique is of primary importance during the development of transgenic mosquitoes. The study describes the variable factors that influence the viability of medically important mosquito vectors during microinjection. Methods: Three mosquito vectors belonging to the genus Aedes, Anopheles and Culex were microinjected at different developmental stages of their life cycle viz., egg, larvae, pupae and adult. Results: The improvisations revealed an increas...

  13. Null vectors of the $WBC_2$ algebra

    CERN Document Server

    Bajnok, Z

    1994-01-01

    Using the fusion principle of Bauer et al. we give explicit expressions for some null vectors in the highest weight representations of the \\bc algebra in two different forms. These null vectors are the generalization of the Virasoro ones described by Benoit and Saint-Aubin and analogues of the $W_3$ ones constructed by Bowcock and Watts. We find connection between quantum Toda models and the fusion method.

  14. Nonperturbative Aspects of Axial Vector Vertex

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; CHEN Xiang-Song; WANG Fan; CHANG Chao-Hsi; ZHAO En-Guang

    2002-01-01

    It is shown how the axial vector current of current quarks is related to that of constituent quarks within the framework of the global color symmetry model.Gluon dressing of the axial vector vertex and the quark self-energy functions are described by the inhomogeneous Bethe-Salpeter equation in the ladder approximation and the Schwinger Dyson equation in the rainbow approximation,respectively.

  15. Students' difficulties with vector calculus in electrodynamics

    OpenAIRE

    2015-01-01

    Understanding Maxwell's equations in differential form is of great importance when studying the electrodynamic phenomena discussed in advanced electromagnetism courses. It is therefore necessary that students master the use of vector calculus in physical situations. In this light we investigated the difficulties second year students at KU Leuven encounter with the divergence and curl of a vector field in mathematical and physical contexts. We have found that they are quite skilled at doing ca...

  16. Light scattering of rectangular slot antennas: parallel magnetic vector vs perpendicular electric vector.

    Science.gov (United States)

    Lee, Dukhyung; Kim, Dai-Sik

    2016-01-07

    We study light scattering off rectangular slot nano antennas on a metal film varying incident polarization and incident angle, to examine which field vector of light is more important: electric vector perpendicular to, versus magnetic vector parallel to the long axis of the rectangle. While vector Babinet's principle would prefer magnetic field along the long axis for optimizing slot antenna function, convention and intuition most often refer to the electric field perpendicular to it. Here, we demonstrate experimentally that in accordance with vector Babinet's principle, the incident magnetic vector parallel to the long axis is the dominant component, with the perpendicular incident electric field making a small contribution of the factor of 1/|ε|, the reciprocal of the absolute value of the dielectric constant of the metal, owing to the non-perfectness of metals at optical frequencies.

  17. Effects of Climate and Climate Change on Vectors and Vector-Borne Diseases: Ticks Are Different.

    Science.gov (United States)

    Ogden, Nick H; Lindsay, L Robbin

    2016-08-01

    There has been considerable debate as to whether global risk from vector-borne diseases will be impacted by climate change. This has focussed on important mosquito-borne diseases that are transmitted by the vectors from infected to uninfected humans. However, this debate has mostly ignored the biological diversity of vectors and vector-borne diseases. Here, we review how climate and climate change may impact those most divergent of arthropod disease vector groups: multivoltine insects and hard-bodied (ixodid) ticks. We contrast features of the life cycles and behaviour of these arthropods, and how weather, climate, and climate change may have very different impacts on the spatiotemporal occurrence and abundance of vectors, and the pathogens they transmit.

  18. An Algorithm for Interpolating Ship Motion Vectors

    Directory of Open Access Journals (Sweden)

    Qinyou Hu

    2014-03-01

    Full Text Available Interpolation of ship motion vectors is able to be used for estimating the lost ship AIS dynamic information, which is important for replaying marine accidents and for analysing marine traffic data. The previous methods can only interpolate ship's position, while not including ship's course and speed. In this paper, vector function is used to express the relationship between the ship's time and space coordinates, and the tangent of the vector function and its change rate are able to express physical characteristics of ship's course, speed and acceleration. The given AIS dynamic information can be applied to calculate the parameters of ship's vector function and then the interpolation model for ship motion vectors is developed to estimate the lost ship dynamic information at any given moment. Experiment results show that the ship motion vector function is able to depict the characteristics of ship motions accurately and the model can estimate not only the ship's position but also ship's course and speed at any given moment with limited differences.

  19. An Unbroken Axial Vector Current Conservation Law

    CERN Document Server

    Sharafiddinov, Rasulkhozha S

    2015-01-01

    The mass, energy and momentum of the neutrino of a true flavor have an axial-vector nature. As a consequence, the left-handed truly neutral neutrino in an axial-vector field of emission can be converted into a right-handed one and vice versa. This predicts the unidenticality of masses, energies and momenta of neutrinos of the different components. Recognizing such a difference in masses, energies, momenta and accepting that the left-handed axial-vector neutrino and the right-handed antineutrino of true neutrality refer to long-lived C-odd leptons, and the right-handed truly neutral neutrino and the left-handed axial-vector antineutrino are of short-lived fermions of C-oddity, we would write a new CP-even Dirac equation taking into account the flavor symmetrical axial-vector mass, energy and momentum matrices. Their presence explains the spontaneous mirror symmetry violation, confirming that an axial-vector current conservation law has never violated. They reflect the availability of a mirror Minkowski space i...

  20. Validation of the detection of STEC (O26, O45, O103, O111, O121, O145 and O157 in raw burgers using real-time PCR (BAX® System Q7, DuPont in “WET POOLS”

    Directory of Open Access Journals (Sweden)

    Paula Mussio

    2014-12-01

    Full Text Available Shiga toxin-producing Escherichia coli (STEC O157:H7 and no-O157:H7 have been identified as emerging foodborne pathogens responsible for an increasing number of outbreaks worldwide. Many foods have been associated to these outbreaks, mainly undercooked beef burgers. Due to the increasing production and consumption of burgers in our country, it is important to have a rapid technique to identify and isolate the most important STEC strains in foods matrixes.The objective of these investigation was to assess the sensitivity, specificity and limit detection for the screening of the most prevalent STEC in frozen raw beef burgers, using the "STEC Screening stx/eae " kit to detect the stx/eae genes and the "Panel 1 STEC E. coli O26, O111, O121" and "Panel 2 STEC E. coli O45, O103, O145" and "E. coli O157: H7 MP” (DuPont kits for the detection of the different serogroups. The use of composed samples (wet pools, the recovery of each strain from the positives samples on selective media after specified inmunoconcentration and the detection of stx/eae virulence genes in isolates by PCR were also evaluated. We validated a technique that allows the detection of the mentioned STEC strains with limits of detection between 1-5 CFU in 65 grams of raw frozen hamburgers, using wet pools.