International Nuclear Information System (INIS)
Biazar, J.; Eslami, M.; Aminikhah, H.
2009-01-01
In this article, an application of He's homotopy perturbation method is applied to solve systems of Volterra integral equations of the first kind. Some non-linear examples are prepared to illustrate the efficiency and simplicity of the method. Applying the method for linear systems is so easily that it does not worth to have any example.
Energy Technology Data Exchange (ETDEWEB)
Moriceau, Y [Commissariat a l' Energie Atomique, Centre d' Etudes de Limeil, 94 - Villeneuve-Saint-Georges (France)
1968-03-01
It is well known, if not well explained, that photo cross-sections curves depend on numerical resolution; as well as many other physical solutions from integral equations of the first kind, they are oscillating. In the first part of this report, a typical example points out how oscillations are growing. In the second part, a new method is explained yielding a smooth resolution. From experimental data on equidistant intervals, we build functions expanded in Tchebycheff polynomials; the solution is of this kind. Then, the third part points out that semi-analytical resolutions of this problem are illusive. (author) [French] C'est un fait reconnu mais mal explique, que les courbes de sections efficaces photonucleaires dependent de la resolution numerique adoptee. Beaucoup d'autres solutions physiques extraites d'une equation integrale de 1ere espece sont dans ce cas; elles sont arbitraires et oscillatoires. Dans la 1ere partie de ce rapport, on montre, dans un cas particulier typique, comment se forment les oscillations. Dans la 2eme partie, on presente une methode originale qui permet d'obtenir une resolution exempte d'oscillations. A partir de donnees experimentales a intervalles equidistants, on construit des fonctions developpees en polynomes de Tchebycheff; la solution est de ce type. Enfin, on montre dans la 3eme partie que les resolutions semi-analytiques de ce probleme sont illusoires. (auteur)
Integral equations of the first kind, inverse problems and regularization: a crash course
International Nuclear Information System (INIS)
Groetsch, C W
2007-01-01
This paper is an expository survey of the basic theory of regularization for Fredholm integral equations of the first kind and related background material on inverse problems. We begin with an historical introduction to the field of integral equations of the first kind, with special emphasis on model inverse problems that lead to such equations. The basic theory of linear Fredholm equations of the first kind, paying particular attention to E. Schmidt's singular function analysis, Picard's existence criterion, and the Moore-Penrose theory of generalized inverses is outlined. The fundamentals of the theory of Tikhonov regularization are then treated and a collection of exercises and a bibliography are provided
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Mohammad Almousa
2013-01-01
Full Text Available The aim of this study is to present the use of a semi analytical method called the optimal homotopy asymptotic method (OHAM for solving the linear Fredholm integral equations of the first kind. Three examples are discussed to show the ability of the method to solve the linear Fredholm integral equations of the first kind. The results indicated that the method is very effective and simple.
Fibonacci-regularization method for solving Cauchy integral equations of the first kind
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Mohammad Ali Fariborzi Araghi
2017-09-01
Full Text Available In this paper, a novel scheme is proposed to solve the first kind Cauchy integral equation over a finite interval. For this purpose, the regularization method is considered. Then, the collocation method with Fibonacci base function is applied to solve the obtained second kind singular integral equation. Also, the error estimate of the proposed scheme is discussed. Finally, some sample Cauchy integral equations stem from the theory of airfoils in fluid mechanics are presented and solved to illustrate the importance and applicability of the given algorithm. The tables in the examples show the efficiency of the method.
Fymat, A. L.
1975-01-01
The determination of the microstructure, chemical nature, and dynamical evolution of scattering particulates in the atmosphere is considered. A description is given of indirect sampling techniques which can circumvent most of the difficulties associated with direct sampling techniques, taking into account methods based on scattering, extinction, and diffraction of an incident light beam. Approaches for reconstructing the particulate size distribution from the direct and the scattered radiation are discussed. A new method is proposed for determining the chemical composition of the particulates and attention is given to the relevance of methods of solution involving first kind Fredholm integral equations.
Integrability of some generalized Lotka - Volterra systems
Energy Technology Data Exchange (ETDEWEB)
Bountis, T.C.; Bier, M.; Hijmans, J.
1983-08-08
Several integrable systems of nonlinear ordinary differential equations of the Lotka-Volterra type are identified by the Painleve property and completely integrated. One such integrable case of N first order ode's is found, with N - 2 free parameters and N arbitrary. The concept of integrability of a general dynamical system, not necessarily derived from a hamiltonian, is also discussed.
On a Volterra Stieltjes integral equation
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P. T. Vaz
1990-01-01
Full Text Available The paper deals with a study of linear Volterra integral equations involving Lebesgue-Stieltjes integrals in two independent variables. The authors prove an existence theorem using the Banach fixed-point principle. An explicit example is also considered.
Eshkuvatov, Z K; Zulkarnain, F S; Nik Long, N M A; Muminov, Z
2016-01-01
Modified homotopy perturbation method (HPM) was used to solve the hypersingular integral equations (HSIEs) of the first kind on the interval [-1,1] with the assumption that the kernel of the hypersingular integral is constant on the diagonal of the domain. Existence of inverse of hypersingular integral operator leads to the convergence of HPM in certain cases. Modified HPM and its norm convergence are obtained in Hilbert space. Comparisons between modified HPM, standard HPM, Bernstein polynomials approach Mandal and Bhattacharya (Appl Math Comput 190:1707-1716, 2007), Chebyshev expansion method Mahiub et al. (Int J Pure Appl Math 69(3):265-274, 2011) and reproducing kernel Chen and Zhou (Appl Math Lett 24:636-641, 2011) are made by solving five examples. Theoretical and practical examples revealed that the modified HPM dominates the standard HPM and others. Finally, it is found that the modified HPM is exact, if the solution of the problem is a product of weights and polynomial functions. For rational solution the absolute error decreases very fast by increasing the number of collocation points.
Automatic Control Systems Modeling by Volterra Polynomials
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S. V. Solodusha
2012-01-01
Full Text Available The problem of the existence of the solutions of polynomial Volterra integral equations of the first kind of the second degree is considered. An algorithm of the numerical solution of one class of Volterra nonlinear systems of the first kind is developed. Numerical results for test examples are presented.
Integrable deformations of Lotka-Volterra systems
International Nuclear Information System (INIS)
Ballesteros, Angel; Blasco, Alfonso; Musso, Fabio
2011-01-01
The Hamiltonian structure of a class of three-dimensional (3D) Lotka-Volterra (LV) equations is revisited from a novel point of view by showing that the quadratic Poisson structure underlying its integrability structure is just a real three-dimensional Poisson-Lie group. As a consequence, the Poisson coalgebra map Δ (2) that is given by the group multiplication provides the keystone for the explicit construction of a new family of 3N-dimensional integrable systems that, under certain constraints, contain N sets of deformed versions of the 3D LV equations. Moreover, by considering the most generic Poisson-Lie structure on this group, a new two-parametric integrable perturbation of the 3D LV system through polynomial and rational perturbation terms is explicitly found. -- Highlights: → A new Poisson-Lie approach to the integrability of Lotka-Volterra system is given. → New integrable deformations of the 3D Lotka-Volterra system are obtained. → Integrable Lotka-Volterra-type equations in 3N dimensions are deduced.
On a new class of integrals involving Bessel functions of the first kind
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P. Agarwal
2014-06-01
Full Text Available In recent years, several integral formulas involving a variety of special functions have been developed by many authors. Also many integral formulas containing the Bessel function $J_\
On the integrability of some generalized Lotka-Volterra systems
Bier, M.; Hijmans, J.; Bountis, T. C.
1983-08-01
Several integrable systems of nonlinear ordinary differential equations of the Lotka-Volterra type are identified by the Painleveproperty and completely integrated. One such integrable case of N first order ode's is found, with N-2 free parameters and N arbitrary. The concept of integrability of a general dynamical system, not necessarily derived from a Hamiltonian, is also discussed.
Prediction of rotor blade-vortex interaction using Volterra integrals
Energy Technology Data Exchange (ETDEWEB)
Wong, A.; Nitzsche, F. [Carleton Univ., Dept. of Mechanical and Aerospace Engineering, Ottawa, Ontario (Canada)]. E-mail: Fred_Nitzsche@carleton.ca; Khalid, M. [National Research Council Canada, Inst. for Aerospace Research, Ottawa, Ontario (Canada)
2004-07-01
The theory of Volterra integral equations for nonlinear system is applied to the prediction of the nonlinear aerodynamic response of an NACA 0012 airfoil experiencing blade-vortex interaction. The phenomenon is first modeled in two-dimensions using an Euler/Navier-Stoke code, and the resulting unsteady aerodynamic flow field sequences are appropriately combined to form a training dataset. The Volterra kernels are identified in the time-domain characteristics of the selected data, which is in turn used to predict the nonlinear aerodynamic response of the airfoil. The Volterra kernel based data is then compared against a standard airfoil response. The predicted lift time histories of the airfoil are shown to be in good agreement with the aerodynamic data. (author)
Prediction of rotor blade-vortex interaction using Volterra integrals
International Nuclear Information System (INIS)
Wong, A.; Nitzsche, F.; Khalid, M.
2004-01-01
The theory of Volterra integral equations for nonlinear system is applied to the prediction of the nonlinear aerodynamic response of an NACA 0012 airfoil experiencing blade-vortex interaction. The phenomenon is first modeled in two-dimensions using an Euler/Navier-Stoke code, and the resulting unsteady aerodynamic flow field sequences are appropriately combined to form a training dataset. The Volterra kernels are identified in the time-domain characteristics of the selected data, which is in turn used to predict the nonlinear aerodynamic response of the airfoil. The Volterra kernel based data is then compared against a standard airfoil response. The predicted lift time histories of the airfoil are shown to be in good agreement with the aerodynamic data. (author)
International Nuclear Information System (INIS)
Liu Chunliang; Xie Xi; Chen Yinbao
1991-01-01
The universal nonlinear dynamic system equation is equivalent to its nonlinear Volterra's integral equation, and any order approximate analytical solution of the nonlinear Volterra's integral equation is obtained by exact analytical method, thus giving another derivation procedure as well as another computation algorithm for the solution of the universal nonlinear dynamic system equation
Periodic solutions of Volterra integral equations
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M. N. Islam
1988-01-01
Full Text Available Consider the system of equationsx(t=f(t+∫−∞tk(t,sx(sds, (1andx(t=f(t+∫−∞tk(t,sg(s,x(sds. (2Existence of continuous periodic solutions of (1 is shown using the resolvent function of the kernel k. Some important properties of the resolvent function including its uniqueness are obtained in the process. In obtaining periodic solutions of (1 it is necessary that the resolvent of k is integrable in some sense. For a scalar convolution kernel k some explicit conditions are derived to determine whether or not the resolvent of k is integrable. Finally, the existence and uniqueness of continuous periodic solutions of (1 and (2 are btained using the contraction mapping principle as the basic tool.
On various integrable discretizations of a general two-component Volterra system
International Nuclear Information System (INIS)
Babalic, Corina N; Carstea, A S
2013-01-01
We present two integrable discretizations of a general differential–difference bicomponent Volterra system. The results are obtained by discretizing directly the corresponding Hirota bilinear equations in two different ways. Multisoliton solutions are presented together with a new discrete form of Lotka–Volterra equation obtained by an alternative bilinearization. (paper)
International Nuclear Information System (INIS)
Mesgarani, H; Parmour, P; Aghazadeh, N
2010-01-01
In this paper, we apply Aitken extrapolation and epsilon algorithm as acceleration technique for the solution of a weakly singular nonlinear Volterra integral equation of the second kind. In this paper, based on Tao and Yong (2006 J. Math. Anal. Appl. 324 225-37.) the integral equation is solved by Navot's quadrature formula. Also, Tao and Yong (2006) for the first time applied Richardson extrapolation to accelerating convergence for the weakly singular nonlinear Volterra integral equations of the second kind. To our knowledge, this paper may be the first attempt to apply Aitken extrapolation and epsilon algorithm for the weakly singular nonlinear Volterra integral equations of the second kind.
Classification of integrable Volterra-type lattices on the sphere: isotropic case
International Nuclear Information System (INIS)
Adler, V E
2008-01-01
The symmetry approach is used for classification of integrable isotropic vector Volterra lattices on the sphere. The list of integrable lattices consists mainly of new equations. Their symplectic structure and associated PDE of vector NLS type are discussed
On the Volterra integral equation relating creep and relaxation
International Nuclear Information System (INIS)
Anderssen, R S; De Hoog, F R; Davies, A R
2008-01-01
The evolving stress–strain response of a material to an applied deformation is causal. If the current response depends on the earlier history of the stress–strain dynamics of the material (i.e. the material has memory), then Volterra integral equations become the natural framework within which to model the response. For viscoelastic materials, when the response is linear, the dual linear Boltzmann causal integral equations are the appropriate model. The choice of one rather than the other depends on whether the applied deformation is a stress or a strain, and the associated response is, respectively, a creep or a relaxation. The duality between creep and relaxation is known explicitly and is referred to as the 'interconversion equation'. Rheologically, its importance relates to the fact that it allows the creep to be determined from knowledge of the relaxation and vice versa. Computationally, it has been known for some time that the recovery of the relaxation from the creep is more problematic than the creep from the relaxation. Recent research, using discrete models for the creep and relaxation, has confirmed that this is an essential feature of interconversion. In this paper, the corresponding result is generalized for continuous models of the creep and relaxation
Numerical Study of Two-Dimensional Volterra Integral Equations by RDTM and Comparison with DTM
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Reza Abazari
2013-01-01
Full Text Available The two-dimensional Volterra integral equations are solved using more recent semianalytic method, the reduced differential transform method (the so-called RDTM, and compared with the differential transform method (DTM. The concepts of DTM and RDTM are briefly explained, and their application to the two-dimensional Volterra integral equations is studied. The results obtained by DTM and RDTM together are compared with exact solution. As an important result, it is depicted that the RDTM results are more accurate in comparison with those obtained by DTM applied to the same Volterra integral equations. The numerical results reveal that the RDTM is very effective, convenient, and quite accurate compared to the other kind of nonlinear integral equations. It is predicted that the RDTM can be found widely applicable in engineering sciences.
Lp-valued stochastic convolution integral driven by Volterra noise
Czech Academy of Sciences Publication Activity Database
Čoupek, P.; Maslowski, B.; Ondreját, Martin
2018-01-01
Roč. 18, č. 6 (2018), č. článku 1850048. ISSN 0219-4937 R&D Projects: GA ČR(CZ) GA15-08819S Institutional support: RVO:67985556 Keywords : Volterra process * Rosenblatt process * hypercontractivity Subject RIV: BA - General Mathematics Impact factor: 0.820, year: 2016
DEFF Research Database (Denmark)
E. Barndorff-Nielsen, Ole; Benth, Fred Espen; Szozda, Benedykt
This paper generalizes the integration theory for volatility modulated Brownian-driven Volterra processes onto the space G* of Potthoff-Timpel distributions. Sufficient conditions for integrability of generalized processes are given, regularity results and properties of the integral are discussed...
DEFF Research Database (Denmark)
Barndorff-Nielsen, Ole E.; Benth, Fred Espen; Szozda, Benedykt
This paper generalizes the integration theory for volatility modulated Brownian-driven Volterra processes onto the space G∗ of Potthoff--Timpel distributions. Sufficient conditions for integrability of generalized processes are given, regularity results and properties of the integral are discusse...
Xu, Run; Ma, Xiangting
2017-01-01
In this paper, we establish some new retarded nonlinear Volterra-Fredholm type integral inequalities with maxima in two independent variables, and we present the applications to research the boundedness of solutions to retarded nonlinear Volterra-Fredholm type integral equations.
Al Jarro, Ahmed
2011-09-01
A new predictor-corrector scheme for solving the Volterra integral equation to analyze transient electromagnetic wave interactions with arbitrarily shaped inhomogeneous dielectric bodies is considered. Numerical results demonstrating stability and accuracy of the proposed method are presented. © 2011 IEEE.
The Volterra's integral equation theory for accelerator single-freedom nonlinear components
International Nuclear Information System (INIS)
Wang Sheng; Xie Xi
1996-01-01
The Volterra's integral equation equivalent to the dynamic equation of accelerator single-freedom nonlinear components is given, starting from which the transport operator of accelerator single-freedom nonlinear components and its inverse transport operator are obtained. Therefore, another algorithm for the expert system of the beam transport operator of accelerator single-freedom nonlinear components is developed
International Nuclear Information System (INIS)
Biazar, J.; Ghazvini, H.
2009-01-01
In this paper, the He's homotopy perturbation method is applied to solve systems of Volterra integral equations of the second kind. Some examples are presented to illustrate the ability of the method for linear and non-linear such systems. The results reveal that the method is very effective and simple.
International Nuclear Information System (INIS)
Dubovik, V.M.; Galperin, A.G.; Richvitsky, V.S.; Slepnyov, S.K.
2000-01-01
A study of a certain subset of Volterra equations has revealed that some statements about time-independent constants of motion, Hamiltonian functions, and Poisson structure matrices appearing in the Lotka-Volterra equations, either regarded as proven or of the sort that could be proven, are not valid, in fact. Particular cases are given as examples to explain the reasons for the occurring phenomena
Numerical Solution of Nonlinear Volterra Integral Equations System Using Simpson’s 3/8 Rule
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Adem Kılıçman
2012-01-01
Full Text Available The Simpson’s 3/8 rule is used to solve the nonlinear Volterra integral equations system. Using this rule the system is converted to a nonlinear block system and then by solving this nonlinear system we find approximate solution of nonlinear Volterra integral equations system. One of the advantages of the proposed method is its simplicity in application. Further, we investigate the convergence of the proposed method and it is shown that its convergence is of order O(h4. Numerical examples are given to show abilities of the proposed method for solving linear as well as nonlinear systems. Our results show that the proposed method is simple and effective.
A predictor-corrector scheme for solving the Volterra integral equation
Al Jarro, Ahmed
2011-08-01
The occurrence of late time instabilities is a common problem of almost all time marching methods developed for solving time domain integral equations. Implicit marching algorithms are now considered stable with various efforts that have been developed for removing low and high frequency instabilities. On the other hand, literature on stabilizing explicit schemes, which might be considered more efficient since they do not require a matrix inversion at each time step, is practically non-existent. In this work, a stable but still explicit predictor-corrector scheme is proposed for solving the Volterra integral equation and its efficacy is verified numerically. © 2011 IEEE.
On the existence of solutions for Volterra integral inclusions in Banach spaces
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Evgenios P. Avgerinos
1993-01-01
Full Text Available In this paper we examine a class of nonlinear integral inclusions defined in a separable Banach space. For this class of inclusions of Volterra type we establish two existence results, one for inclusions with a convex-valued orientor field and the other for inclusions with nonconvex-valued orientor field. We present conditions guaranteeing that the multivalued map that represents the right-hand side of the inclusion is α-condensing using for the proof of our results a known fixed point theorem for α-condensing maps.
Accurate and efficient quadrature for volterra integral equations
International Nuclear Information System (INIS)
Knirk, D.L.
1976-01-01
Four quadrature schemes were tested and compared in considerable detail to determine their usefulness in the noniterative integral equation method for single-channel quantum-mechanical calculations. They are two forms of linear approximation (trapezoidal rule) and two forms of quadratic approximation (Simpson's rule). Their implementation in this method is shown, a formal discussion of error propagation is given, and tests are performed to determine actual operating characteristics on various bound and scattering problems in different potentials. The quadratic schemes are generally superior to the linear ones in terms of accuracy and efficiency. The previous implementation of Simpson's rule is shown to possess an inherent instability which requires testing on each problem for which it is used to assure its reliability. The alternative quadratic approximation does not suffer this deficiency, but still enjoys the advantages of higher order. In addition, the new scheme obeys very well an h 4 Richardson extrapolation, whereas the old one does so rather poorly. 6 figures, 11 tables
Al Jarro, Ahmed; Bagci, Hakan
2011-01-01
A hybrid MPI/OpenMP scheme for efficiently parallelizing the explicit marching-on-in-time (MOT)-based solution of the time-domain volume (Volterra) integral equation (TD-VIE) is presented. The proposed scheme equally distributes tested field values
International Nuclear Information System (INIS)
Cairo, Laurent; Llibre, Jaume
2007-01-01
We classify all the global phase portraits of the cubic polynomial vector fields of Lotka-Volterra type having a rational first integral of degree 2. For such vector fields there are exactly 28 different global phase portraits in the Poincare disc up to a reversal of sense of all orbits
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Farshid Mirzaee
2014-06-01
Full Text Available In this paper, we present a numerical method for solving two-dimensional Fredholm–Volterra integral equations (F-VIE. The method reduces the solution of these integral equations to the solution of a linear system of algebraic equations. The existence and uniqueness of the solution and error analysis of proposed method are discussed. The method is computationally very simple and attractive. Finally, numerical examples illustrate the efficiency and accuracy of the method.
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Partov Doncho
2017-01-01
Full Text Available The paper presents analysis of the stress-strain behaviour and deflection changes due to creep in statically determinate composite steel-concrete beam according to EUROCODE 2, ACI209R-92 and Gardner&Lockman models. The mathematical model involves the equation of equilibrium, compatibility and constitutive relationship, i.e. an elastic law for the steel part and an integral-type creep law of Boltzmann - Volterra for the concrete part considering the above mentioned models. On the basis of the theory of viscoelastic body of Maslov-Arutyunian-Trost-Zerna-Bažant for determining the redistribution of stresses in beam section between concrete plate and steel beam with respect to time 't', two independent Volterra integral equations of the second kind have been derived. Numerical method based on linear approximation of the singular kernel function in the integral equation is presented. Example with the model proposed is investigated.
International Nuclear Information System (INIS)
Itoh, Yoshiaki
2009-01-01
The combinatorial method is useful to obtain conserved quantities for some nonlinear integrable systems, as an alternative to the Lax representation method. Here we extend the combinatorial method and introduce an elementary geometry to show the vanishing of the Poisson brackets of the Hamiltonian structure for a Lotka-Volterra system of competing species. We associate a set of points on a circle with a set of species of the Lotka-Volterra system, where the dominance relations between points are given by the dominance relations between the species. We associate each term of the conserved quantities with a subset of points on the circle, which simplifies to show the vanishing of the Poisson brackets
Gravel, Simon; Thibault, Pierre
In this paper, we consider normalizability, integrability and linearizability properties of the Lotka-Volterra system in the neighborhood of a singular point with eigenvalues 1 and - λ. The results are obtained by generalizing and expanding two methods already known: the power expansion of the first integral or of the linearizing transformation and the transformation of the saddle into a node. With these methods we find conditions that are valid for λ∈ R+ or λ∈ Q. These conditions will allow us to find all the integrable and linearizable systems for λ= {p}/{2} and {2}/{p} with p∈ N+.
On generalized Volterra systems
Charalambides, S. A.; Damianou, P. A.; Evripidou, C. A.
2015-01-01
We construct a large family of evidently integrable Hamiltonian systems which are generalizations of the KM system. The algorithm uses the root system of a complex simple Lie algebra. The Hamiltonian vector field is homogeneous cubic but in a number of cases a simple change of variables transforms such a system to a quadratic Lotka-Volterra system. We present in detail all such systems in the cases of A3, A4 and we also give some examples from higher dimensions. We classify all possible Lotka-Volterra systems that arise via this algorithm in the An case.
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Haotao Cai
2017-01-01
Full Text Available We develop a generalized Jacobi-Galerkin method for second kind Volterra integral equations with weakly singular kernels. In this method, we first introduce some known singular nonpolynomial functions in the approximation space of the conventional Jacobi-Galerkin method. Secondly, we use the Gauss-Jacobi quadrature rules to approximate the integral term in the resulting equation so as to obtain high-order accuracy for the approximation. Then, we establish that the approximate equation has a unique solution and the approximate solution arrives at an optimal convergence order. One numerical example is presented to demonstrate the effectiveness of the proposed method.
Al Jarro, Ahmed
2011-08-01
A hybrid MPI/OpenMP scheme for efficiently parallelizing the explicit marching-on-in-time (MOT)-based solution of the time-domain volume (Volterra) integral equation (TD-VIE) is presented. The proposed scheme equally distributes tested field values and operations pertinent to the computation of tested fields among the nodes using the MPI standard; while the source field values are stored in all nodes. Within each node, OpenMP standard is used to further accelerate the computation of the tested fields. Numerical results demonstrate that the proposed parallelization scheme scales well for problems involving three million or more spatial discretization elements. © 2011 IEEE.
Theoretical study on the first kind of density wave instabilities
Energy Technology Data Exchange (ETDEWEB)
Zuying, Gao; Jincai, Li; Baocheng, Xu; Zuoyi, Zhang; Cheng, Gao [Institute of Nuclear Energy and Technology, Tsingua Univ., Beijing (China)
1997-09-01
The present paper summarizes the theoretical studies carried out by INET (Institute of Nuclear Energy Technology) of Tsinghua University on the first kind of density wave instabilities (DWIs) of natural circulation systems. The analysis methods of DWI and mathematical models of drift flux are presented. Based on the general excess entropy production criterion of non-equilibrium thermodynamics, an energy principle of DWI is established. (author). 10 refs, 16 figs.
An integrable symmetric (2+1)-dimensional Lotka-Volterra equation and a family of its solutions
International Nuclear Information System (INIS)
Hu Xingbiao; Li Chunxia; Nimmo, Jonathan J C; Yu Guofu
2005-01-01
A symmetric (2+1)-dimensional Lotka-Volterra equation is proposed. By means of a dependent variable transformation, the equation is firstly transformed into multilinear form and further decoupled into bilinear form by introducing auxiliary independent variables. A bilinear Baecklund transformation is found and then the corresponding Lax pair is derived. Explicit solutions expressed in terms of pfaffian solutions of the bilinear form of the symmetric (2+1)-dimensional Lotka-Volterra equation are given. As a special case of the pfaffian solutions, we obtain soliton solutions and dromions
A predictor-corrector scheme for solving the Volterra integral equation
Al Jarro, Ahmed; Bagci, Hakan
2011-01-01
The occurrence of late time instabilities is a common problem of almost all time marching methods developed for solving time domain integral equations. Implicit marching algorithms are now considered stable with various efforts that have been
Zhao, Peng; Fan, Engui
2015-04-01
In this paper, a new type of integrable differential-difference hierarchy, namely, the generalized relativistic Lotka-Volterra (GRLV) hierarchy, is introduced. This hierarchy is closely related to Lotka-Volterra lattice and relativistic Lotka-Volterra lattice, which allows us to provide a unified and effective way to obtain some exact solutions for both the Lotka-Volterra hierarchy and the relativistic Lotka-Volterra hierarchy. In particular, we shall construct algebro-geometric quasiperiodic solutions for the LV hierarchy and the RLV hierarchy in a unified manner on the basis of the finite gap integration theory.
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Masato Shinjo
2015-12-01
Full Text Available The Hankel determinant appears in representations of solutions to several integrable systems. An asymptotic expansion of the Hankel determinant thus plays a key role in the investigation of asymptotic analysis of such integrable systems. This paper presents an asymptotic expansion formula of a certain Casorati determinant as an extension of the Hankel case. This Casorati determinant is then shown to be associated with the solution to the discrete hungry Lotka–Volterra (dhLV system, which is an integrable variant of the famous prey–predator model in mathematical biology. Finally, the asymptotic behavior of the dhLV system is clarified using the expansion formula for the Casorati determinant.
Optimal control of stochastic difference Volterra equations an introduction
Shaikhet, Leonid
2015-01-01
This book showcases a subclass of hereditary systems, that is, systems with behaviour depending not only on their current state but also on their past history; it is an introduction to the mathematical theory of optimal control for stochastic difference Volterra equations of neutral type. As such, it will be of much interest to researchers interested in modelling processes in physics, mechanics, automatic regulation, economics and finance, biology, sociology and medicine for all of which such equations are very popular tools. The text deals with problems of optimal control such as meeting given performance criteria, and stabilization, extending them to neutral stochastic difference Volterra equations. In particular, it contrasts the difference analogues of solutions to optimal control and optimal estimation problems for stochastic integral Volterra equations with optimal solutions for corresponding problems in stochastic difference Volterra equations. Optimal Control of Stochastic Difference Volterra Equation...
On vector analogs of the modified Volterra lattice
Energy Technology Data Exchange (ETDEWEB)
Adler, V E; Postnikov, V V [L D Landau Institute for Theoretical Physics, 1a Semenov pr, 142432 Chernogolovka (Russian Federation); Sochi Branch of Peoples' Friendship University of Russia, 32 Kuibyshev str, 354000 Sochi (Russian Federation)], E-mail: adler@itp.ac.ru, E-mail: postnikovvv@rambler.ru
2008-11-14
The zero curvature representations, Baecklund transformations, nonlinear superposition principle and the simplest explicit solutions of soliton and breather type are presented for two vector generalizations of modified Volterra lattice. The relations with some other integrable equations are established.
Composite spectral functions for solving Volterra's population model
International Nuclear Information System (INIS)
Ramezani, M.; Razzaghi, M.; Dehghan, M.
2007-01-01
An approximate method for solving Volterra's population model for population growth of a species in a closed system is proposed. Volterra's model is a nonlinear integro-differential equation, where the integral term represents the effect of toxin. The approach is based upon composite spectral functions approximations. The properties of composite spectral functions consisting of few terms of orthogonal functions are presented and are utilized to reduce the solution of the Volterra's model to the solution of a system of algebraic equations. The method is easy to implement and yields very accurate result
Solvability of Urysohn and Urysohn-Volterra equations with hysteresis in weighted spaces
International Nuclear Information System (INIS)
Darwish Mohamed Abdalla
2005-09-01
The existence of solutions to nonlinear integral equations of the second kind with hysteresis, of Urysohn-Volterra and Urysohn types has been established. We develop the solvability theory of Urysohn-Volterra equation with hysteresis in weighted spaces proposed by the author [M.A. Darwish, On solvability of Urysohn-Volterra equations with hysteresis in weighted spaces, J. Integral Equations and Application, 14(2) (2002), 151-163]. (author)
Volterra, Fascism, and France.
Capristo, Annalisa
2015-12-01
My contribution focuses on two aspects strictly related each other. On one hand, the progressive marginalization of Volterra from Italian scientific and political life after the rise of Fascism - because of his public anti-Fascist stance, both as a senator and as a professor - until his definitive exclusion on racial grounds in 1938. On the other hand, the reactions of his French colleagues and friends to this ostracism, and the support he received from them. As it emerges from several sources (Volterra's correspondence, institutional documentation, conference proceedings, etc.), it was mainly thanks to their support that he was able to escape the complete isolation and the "civil death" to which the regime condemned many of its adversaries.
Generalized symmetries and conserved quantities of the Lotka-Volterra model
Baumann, G.; Freyberger, M.
1991-07-01
We examine the generalized symmetries of the Lotka-Volterra model to find the parameter values at which one time-dependent integral of motion exists. In this case the integral can be read off from the symmetries themselves. We also demonstrate the connection to a Hamiltonian structure of the Lotka-Volterra model.
Some Identities Involving the Derivative of the First Kind Chebyshev Polynomials
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Tingting Wang
2015-01-01
Full Text Available We use the combinatorial method and algebraic manipulations to obtain several interesting identities involving the power sums of the derivative of the first kind Chebyshev polynomials. This solved an open problem proposed by Li (2015.
On Generalized Fractional Kinetic Equations Involving Generalized Bessel Function of the First Kind
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Dinesh Kumar
2015-01-01
Full Text Available We develop a new and further generalized form of the fractional kinetic equation involving generalized Bessel function of the first kind. The manifold generality of the generalized Bessel function of the first kind is discussed in terms of the solution of the fractional kinetic equation in the paper. The results obtained here are quite general in nature and capable of yielding a very large number of known and (presumably new results.
On the derivative of the Legendre function of the first kind with respect to its degree
International Nuclear Information System (INIS)
Szmytkowski, Radoslaw
2006-01-01
We study the derivative of the Legendre function of the first kind, P ν (z), with respect to its degree ν. At first, we provide two contour integral representations for ∂P ν (z)/∂ν. Then, we proceed to investigate the case of [∂P ν (z)/∂ν] ν=n , with n being an integer; this case is met in some physical and engineering problems. Since it holds that [∂P ν' (z)/∂ν'] ν'==ν-1 -[∂P ν' (z0/∂ν'] ν'=ν , we focus on the sub-case of n being a non-negative integer. We show that ∂P ν (z)/∂ν vertical bar ν=n = P n (z) ln((z+1)/2) + R n (z) (n element of N) where R n (z) is a polynomial in z of degree n. We present alternative derivations of several known explicit expressions for R n (z) and also add some new. A generating function for R n (z) is also constructed. Properties of the polynomials V n (z) = [R n (z) + (-1) n R n (-z)]/2 and W n-1 (z) = -[R n (z) - (-1) n R n (-z)]/2 are also investigated. It is found that W n-1 (z) is the Christoffel polynomial, well known from the theory of the Legendre function of the second kind, Q n (z). As examples of applications of the results obtained, we present non-standard derivations of some representations of Q n (z), sum to closed forms some Legendre series, evaluate some definite integrals involving Legendre polynomials and also derive an explicit representation of the indefinite integral of the Legendre polynomial squared
Singularly perturbed volterra integro-differential equations | Bijura ...
African Journals Online (AJOL)
Several investigations have been made on singularly perturbed integral equations. This paper aims at presenting an algorithm for the construction of asymptotic solutions and then provide a proof asymptotic correctness to singularly perturbed systems of Volterra integro-differential equations. Mathematics Subject
Volterra Series Based Distortion Effect
DEFF Research Database (Denmark)
Agerkvist, Finn T.
2010-01-01
A large part of the characteristic sound of the electric guitar comes from nonlinearities in the signal path. Such nonlinearities may come from the input- or output-stage of the amplier, which is often equipped with vacuum tubes or a dedicated distortion pedal. In this paper the Volterra series...... expansion for non linear systems is investigated with respect to generating good distortion. The Volterra series allows for unlimited adjustment of the level and frequency dependency of each distortion component. Subjectively relevant ways of linking the dierent orders are discussed....
Edelman, Mark
2015-07-01
In this paper, we consider a simple general form of a deterministic system with power-law memory whose state can be described by one variable and evolution by a generating function. A new value of the system's variable is a total (a convolution) of the generating functions of all previous values of the variable with weights, which are powers of the time passed. In discrete cases, these systems can be described by difference equations in which a fractional difference on the left hand side is equal to a total (also a convolution) of the generating functions of all previous values of the system's variable with the fractional Eulerian number weights on the right hand side. In the continuous limit, the considered systems can be described by the Grünvald-Letnikov fractional differential equations, which are equivalent to the Volterra integral equations of the second kind. New properties of the fractional Eulerian numbers and possible applications of the results are discussed.
Lie Point Symmetries and Exact Solutions of the Coupled Volterra System
International Nuclear Information System (INIS)
Ping, Liu; Sen-Yue, Lou
2010-01-01
The coupled Volterra system, an integrable discrete form of a coupled Korteweg–de Vries (KdV) system applied widely in fluids, Bose–Einstein condensation and atmospheric dynamics, is studied with the help of the Lie point symmetries. Two types of delayed differential reduction systems are derived from the coupled Volterra system by means of the symmetry reduction approach and symbolic computation. Cnoidal wave and solitary wave solutions for a delayed differential reduction system and the coupled Volterra system are proposed, respectively. (general)
A theorem regarding roots of the zero-order Bessel function of the first kind
Lin, X.-A.; Agrawal, O. P.
1993-01-01
This paper investigates a problem on the steady-state, conduction-convection heat transfer process in cylindrical porous heat exchangers. The governing partial differential equations for the system are obtained using the energy conservation law. Solution of these equations and the concept of enthalpy lead to a new approach to prove a theorem that the sum of inverse squares of all the positive roots of the zero order Bessel function of the first kind equals to one-forth. As a corollary, it is shown that the sum of one over pth power (p greater than or equal to 2) of the roots converges to some constant.
Monotonicity of the ratio of modified Bessel functions of the first kind with applications.
Yang, Zhen-Hang; Zheng, Shen-Zhou
2018-01-01
Let [Formula: see text] with [Formula: see text] be the modified Bessel functions of the first kind of order v . In this paper, we prove the monotonicity of the function [Formula: see text] on [Formula: see text] for different values of parameter p with [Formula: see text]. As applications, we deduce some new Simpson-Spector-type inequalities for [Formula: see text] and derive a new type of bounds [Formula: see text] ([Formula: see text]) for [Formula: see text]. In particular, we show that the upper bound [Formula: see text] for [Formula: see text] is the minimum over all upper bounds [Formula: see text], where [Formula: see text] and is not comparable with other sharpest upper bounds. We also find such type of upper bounds for [Formula: see text] with [Formula: see text] and for [Formula: see text] with [Formula: see text].
Volterra Filtering for ADC Error Correction
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J. Saliga
2001-09-01
Full Text Available Dynamic non-linearity of analog-to-digital converters (ADCcontributes significantly to the distortion of digitized signals. Thispaper introduces a new effective method for compensation such adistortion based on application of Volterra filtering. Considering ana-priori error model of ADC allows finding an efficient inverseVolterra model for error correction. Efficiency of proposed method isdemonstrated on experimental results.
A Historical Gem from Vito Volterra.
Dunham, William
1990-01-01
Presented is the theorem proposed by Volterra based on the idea that there is no function continuous at each rational point and discontinuous at each irrational point. Discussed are the two conclusions that were drawn by Volterra based on his solution to this problem. (KR)
Asymptotic Behavior of Solutions for Nonlinear Volterra Discrete Equations
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E. Messina
2008-01-01
Full Text Available We consider nonlinear difference equations of unbounded order of the form xi=bi−∑j=0iai,jfi−j(xj, i=0,1,2,…, where fj(x (j=0,…,i are suitable functions. We establish sufficient conditions for the boundedness and the convergence of xi as i→+∞. Some of these conditions are interesting mainly for studying stability of numerical methods for Volterra integral equations.
Demonstration and resolution of the Gibbs paradox of the first kind
International Nuclear Information System (INIS)
Peters, Hjalmar
2014-01-01
The Gibbs paradox of the first kind (GP1) refers to the false increase in entropy which, in statistical mechanics, is calculated from the process of combining two gas systems S1 and S2 consisting of distinguishable particles. Presented in a somewhat modified form, the GP1 manifests as a contradiction to the second law of thermodynamics. Contrary to popular belief, this contradiction affects not only classical but also quantum statistical mechanics. This paper resolves the GP1 by considering two effects. (i) The uncertainty about which particles are located in S1 and which in S2 contributes to the entropies of S1 and S2. (ii) S1 and S2 are correlated by the fact that if a certain particle is located in one system, it cannot be located in the other. As a consequence, the entropy of the total system consisting of S1 and S2 is not the sum of the entropies of S1 and S2. (paper)
A phenomenological Hamiltonian for the Lotka-Volterra problem
International Nuclear Information System (INIS)
Georgian, T.; Findley, G.L.
1996-01-01
We have presented a Hamiltonian theory of phenomenological chemical kinetics. In the present paper, we extend this treatment to the Lotka-Volterra model of sustained oscillations. Our approach begins with the usual definition of an intrinsic reaction coordinate space (x 1 ,x 2 ) for the Lotka-Volterra problem, which leads to the rate equations x 1 =ax 1 -bx 1 x 2 , x 2 =-cx 2 +bx 1 x 2 , with a,b and c being real constants. We thereafter present a Hamiltonian function H(x,y)[y 1 = x 1 and y 2 = x 2 ] and an associated holonomic constraint, which give rise to the above rates as half of Hamilton's equations. We provide trajectories by numerical integration (4th order Runge-Kutta) and show that H(x,y) is a constant of the motion. Finally, issues involved in developing an analytic solution to this problem are discussed
Aeroelastic System Development Using Proper Orthogonal Decomposition and Volterra Theory
Lucia, David J.; Beran, Philip S.; Silva, Walter A.
2003-01-01
This research combines Volterra theory and proper orthogonal decomposition (POD) into a hybrid methodology for reduced-order modeling of aeroelastic systems. The out-come of the method is a set of linear ordinary differential equations (ODEs) describing the modal amplitudes associated with both the structural modes and the POD basis functions for the uid. For this research, the structural modes are sine waves of varying frequency, and the Volterra-POD approach is applied to the fluid dynamics equations. The structural modes are treated as forcing terms which are impulsed as part of the uid model realization. Using this approach, structural and uid operators are coupled into a single aeroelastic operator. This coupling converts a free boundary uid problem into an initial value problem, while preserving the parameter (or parameters) of interest for sensitivity analysis. The approach is applied to an elastic panel in supersonic cross ow. The hybrid Volterra-POD approach provides a low-order uid model in state-space form. The linear uid model is tightly coupled with a nonlinear panel model using an implicit integration scheme. The resulting aeroelastic model provides correct limit-cycle oscillation prediction over a wide range of panel dynamic pressure values. Time integration of the reduced-order aeroelastic model is four orders of magnitude faster than the high-order solution procedure developed for this research using traditional uid and structural solvers.
Directory of Open Access Journals (Sweden)
V. K. Bityukov
2016-01-01
Full Text Available Analytical study of the processes of heat conduction is one of the main topics of modern engineering research in engineering, energy, nuclear industry, process chemical, construction, textile, food, geological and other industries. Suffice to say that almost all processes in one degree or another are related to change in the temperature condition and the transfer of warmth. It should also be noted that engineering studies of the kinetics of a range of physical and chemical processes are similar to the problems of stationary and nonstationary heat transfer. These include the processes of diffusions, sedimentation, viscous flow, slowing down the neutrons, flow of fluids through a porous medium, electric fluctuations, adsorption, drying, burning, etc. There are various methods for solving the classical boundary value problems of nonstationary heat conduction and problems of the generalized type: the method of separation of variables (Fourier method method; the continuation method; the works solutions; the Duhamel's method; the integral transformations method; the operating method; the method of green's functions (stationary and non-stationary thermal conductivity; the reflection method (method source. In this paper, based on the consistent application of the Laplace transform on the dimensionless time θ and finite sine integral transformation in the spatial coordinates X and Y solves the problem of unsteady temperature distribution on the mechanism of heat conduction in a parallelepiped with boundary conditions of first kind. As a result we have the analytical solution of the temperature distribution in the parallelepiped to a conductive mode free convection, when one of the side faces of the parallelepiped is maintained at a constant temperature, and the others with the another same constant temperature.
Hazard Forecasting by MRI: A Prediction Algorithm of the First Kind
Lomnitz, C.
2003-12-01
Seismic gaps do not tell us when and where the next earthquake is due. We present new results on limited earthquake hazard prediction at plate boundaries. Our algorithm quantifies earthquake hazard in seismic gaps. The prediction window found for M7 is on the order of 50 km by 20 years (Lomnitz, 1996a). The earth is unstable with respect to small perturbations of the initial conditions. A prediction of the first kind is an estimate of the time evolution of a complex system with fixed boundary conditions in response to changes in the initial state, for example, weather prediction (Edward Lorenz, 1975; Hasselmann, 2002). We use the catalog of large world earthquakes as a proxy for the initial conditions. The MRI algorithm simulates the response of the system to updating the catalog. After a local stress transient dP the entropy decays as (grad dP)2 due to transient flows directed toward the epicenter. Healing is the thermodynamic process which resets the state of stress. It proceeds as a power law from the rupture boundary inwards, as in a wound. The half-life of a rupture is defined as the healing time which shrinks the size of a scar by half. Healed segments of plate boundary can rupture again. From observations in Chile, Mexico and Japan we find that the half-life of a seismic rupture is about 20 years, in agreement with seismic gap observations. The moment ratio MR is defined as the contrast between the cumulative regional moment release and the local moment deficiency at time t along the plate boundary. The procedure is called MRI. The findings: (1) MRI works; (2) major earthquakes match prominent peaks in the MRI graph; (3) important events (Central Chile 1985; Mexico 1985; Kobe 1995) match MRI peaks which began to emerge 10 to 20 years before the earthquake; (4) The emergence of peaks in MRI depends on earlier ruptures that occurred, not adjacent to but at 10 to 20 fault lengths from the epicentral region, in agreement with triggering effects. The hazard
Revisiting the orthogonality of Bessel functions of the first kind on an infinite interval
International Nuclear Information System (INIS)
Leon, J Ponce de
2015-01-01
The rigorous proof of the orthogonality integral ∫ 0 ∞ ρ J ν (kρ)J ν (k ′ ρ) dρ=((δ(k−k ′ ))/k), for ν>=−1, is laborious and requires the use of mathematical techniques that, probably, are unfamiliar to most physics students, even at the graduate level. In physics, we are used to the argument that it may be proved by the use of Hankel transforms. However, the logic of the matter is the opposite, i.e., the existence of the inverse Hankel transform is a consequence of the orthogonality integral. The goal of this work is to prove this integral without circular reasoning. In this paper, using elementary properties of Bessel functions, we give a simple analytical derivation of this integral for the case where ν is an integer, zero, or half-integer not less than −1/2. Then, using the asymptotic behaviour of J ν (x), we extend the result to any ν>=−1. This work is of a pedagogical nature. Therefore, to add educational value to the discussion, we do not skip the details of the calculations. (paper)
Continuous Multistep Methods for Volterra Integro-Differential
African Journals Online (AJOL)
Kamoh et al.
DIFFERENTIAL EQUATIONS OF THE SECOND ORDER. 1Kamoh N.M. ... methods, Volterra integro-differential equation, Convergent, ...... Research of a Multistep Method Applied to Numerical Solution of. Volterra ... Congress on Engineering.
On filtering over Îto-Volterra observations
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Michael V. Basin
2000-01-01
Full Text Available In this paper, the Kalman-Bucy filter is designed for an Îto-Volterra process over Ito-Volterra observations that cannot be reduced to the case of a differential observation equation. The Kalman-Bucy filter is then designed for an Ito-Volterra process over discontinuous Ito-Volterra observations. Based on the obtained results, the filtering problem over discrete observations with delays is solved. Proofs of the theorems substantiating the filtering algorithms are given.
Tang, Xianhua; Cao, Daomin; Zou, Xingfu
We consider a periodic Lotka-Volterra competition system without instantaneous negative feedbacks (i.e., pure-delay systems) x(t)=x(t)[r(t)-∑j=1na(t)x(t-τ(t))], i=1,2,…,n. We establish some 3/2-type criteria for global attractivity of a positive periodic solution of the system, which generalize the well-known Wright's 3/2 criteria for the autonomous delay logistic equation, and thereby, address the open problem proposed by both Kuang [Y. Kuang, Global stability in delayed nonautonomous Lotka-Volterra type systems without saturated equilibria, Differential Integral Equations 9 (1996) 557-567] and Teng [Z. Teng, Nonautonomous Lotka-Volterra systems with delays, J. Differential Equations 179 (2002) 538-561].
Generalized Lotka—Volterra systems connected with simple Lie algebras
International Nuclear Information System (INIS)
Charalambides, Stelios A; Damianou, Pantelis A; Evripidou, Charalambos A
2015-01-01
We devise a new method for producing Hamiltonian systems by constructing the corresponding Lax pairs. This is achieved by considering a larger subset of the positive roots than the simple roots of the root system of a simple Lie algebra. We classify all subsets of the positive roots of the root system of type A n for which the corresponding Hamiltonian systems are transformed, via a simple change of variables, to Lotka-Volterra systems. For some special cases of subsets of the positive roots of the root system of type A n , we produce new integrable Hamiltonian systems. (paper)
Generalized Lotka—Volterra systems connected with simple Lie algebras
Charalambides, Stelios A.; Damianou, Pantelis A.; Evripidou, Charalambos A.
2015-06-01
We devise a new method for producing Hamiltonian systems by constructing the corresponding Lax pairs. This is achieved by considering a larger subset of the positive roots than the simple roots of the root system of a simple Lie algebra. We classify all subsets of the positive roots of the root system of type An for which the corresponding Hamiltonian systems are transformed, via a simple change of variables, to Lotka-Volterra systems. For some special cases of subsets of the positive roots of the root system of type An, we produce new integrable Hamiltonian systems.
Quasipolynomial generalization of Lotka-Volterra mappings
International Nuclear Information System (INIS)
Hernandez-Bermejo, Benito; Brenig, Leon
2002-01-01
In recent years, it has been shown that Lotka-Volterra mappings constitute a valuable tool from both the theoretical and the applied points of view, with developments in very diverse fields such as physics, population dynamics, chemistry and economy. The purpose of this work is to demonstrate that many of the most important ideas and algebraic methods that constitute the basis of the quasipolynomial formalism (originally conceived for the analysis of ordinary differential equations) can be extended into the mapping domain. The extension of the formalism into the discrete-time context is remarkable as far as the quasipolynomial methodology had never been shown to be applicable beyond the differential case. It will be demonstrated that Lotka-Volterra mappings play a central role in the quasipolynomial formalism for the discrete-time case. Moreover, the extension of the formalism into the discrete-time domain allows a significant generalization of Lotka-Volterra mappings as well as a whole transfer of algebraic methods into the discrete-time context. The result is a novel and more general conceptual framework for the understanding of Lotka-Volterra mappings as well as a new range of possibilities that become open not only for the theoretical analysis of Lotka-Volterra mappings and their generalizations, but also for the development of new applications. (author)
Quasipolynomial generalization of Lotka-Volterra mappings
Hernández-Bermejo, Benito; Brenig, Léon
2002-07-01
In recent years, it has been shown that Lotka-Volterra mappings constitute a valuable tool from both the theoretical and the applied points of view, with developments in very diverse fields such as physics, population dynamics, chemistry and economy. The purpose of this work is to demonstrate that many of the most important ideas and algebraic methods that constitute the basis of the quasipolynomial formalism (originally conceived for the analysis of ordinary differential equations) can be extended into the mapping domain. The extension of the formalism into the discrete-time context is remarkable as far as the quasipolynomial methodology had never been shown to be applicable beyond the differential case. It will be demonstrated that Lotka-Volterra mappings play a central role in the quasipolynomial formalism for the discrete-time case. Moreover, the extension of the formalism into the discrete-time domain allows a significant generalization of Lotka-Volterra mappings as well as a whole transfer of algebraic methods into the discrete-time context. The result is a novel and more general conceptual framework for the understanding of Lotka-Volterra mappings as well as a new range of possibilities that become open not only for the theoretical analysis of Lotka-Volterra mappings and their generalizations, but also for the development of new applications.
Nonpolynomial vector fields under the Lotka-Volterra normal form
Hernández-Bermejo, Benito; Fairén, Víctor
1995-02-01
We carry out the generalization of the Lotka-Volterra embedding to flows not explicitly recognizable under the generalized Lotka-Volterra format. The procedure introduces appropriate auxiliary variables, and it is shown how, to a great extent, the final Lotka-Volterra system is independent of their specific definition. Conservation of the topological equivalence during the process is also demonstrated.
Numerical solutions of stochastic Lotka-Volterra equations via operational matrices
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F. Hosseini Shekarabi
2016-03-01
Full Text Available In this paper, an efficient and convenient method for numerical solutions of stochastic Lotka-Volterra dynamical system is proposed. Here, we consider block pulse functions and their operational matrices of integration. Illustrative example is included to demonstrate the procedure and accuracy of the operational matrices based on block pulse functions.
The period function of the generalized Lotka-Volterra centers
Villadelprat, J.
2008-05-01
The present paper deals with the period function of the quadratic centers. In the literature different terminologies are used to classify these centers, but essentially there are four families: Hamiltonian, reversible , codimension four Q4 and generalized Lotka-Volterra systems . Chicone [C. Chicone, Review in MathSciNet, Ref. 94h:58072] conjectured that the reversible centers have at most two critical periods, and that the centers of the three other families have a monotonic period function. With regard to the second part of this conjecture, only the monotonicity of the Hamiltonian and Q4 families [W.A. Coppel, L. Gavrilov, The period function of a Hamiltonian quadratic system, Differential Integral Equations 6 (1993) 1357-1365; Y. Zhao, The monotonicity of period function for codimension four quadratic system Q4, J. Differential Equations 185 (2002) 370-387] has been proved. Concerning the family, no substantial progress has been made since the middle 80s, when several authors showed independently the monotonicity of the classical Lotka-Volterra centers [F. Rothe, The periods of the Volterra-Lokta system, J. Reine Angew. Math. 355 (1985) 129-138; R. Schaaf, Global behaviour of solution branches for some Neumann problems depending on one or several parameters, J. Reine Angew. Math. 346 (1984) 1-31; J. Waldvogel, The period in the Lotka-Volterra system is monotonic, J. Math. Anal. Appl. 114 (1986) 178-184]. By means of the first period constant one can easily conclude that the period function of the centers in the family is monotone increasing near the inner boundary of its period annulus (i.e., the center itself). Thus, according to Chicone's conjecture, it should be also monotone increasing near the outer boundary, which in the Poincaré disc is a polycycle. In this paper we show that this is true. In addition we prove that, except for a zero measure subset of the parameter plane, there is no bifurcation of critical periods from the outer boundary. Finally we
Efficient multidimensional regularization for Volterra series estimation
Birpoutsoukis, Georgios; Csurcsia, Péter Zoltán; Schoukens, Johan
2018-05-01
This paper presents an efficient nonparametric time domain nonlinear system identification method. It is shown how truncated Volterra series models can be efficiently estimated without the need of long, transient-free measurements. The method is a novel extension of the regularization methods that have been developed for impulse response estimates of linear time invariant systems. To avoid the excessive memory needs in case of long measurements or large number of estimated parameters, a practical gradient-based estimation method is also provided, leading to the same numerical results as the proposed Volterra estimation method. Moreover, the transient effects in the simulated output are removed by a special regularization method based on the novel ideas of transient removal for Linear Time-Varying (LTV) systems. Combining the proposed methodologies, the nonparametric Volterra models of the cascaded water tanks benchmark are presented in this paper. The results for different scenarios varying from a simple Finite Impulse Response (FIR) model to a 3rd degree Volterra series with and without transient removal are compared and studied. It is clear that the obtained models capture the system dynamics when tested on a validation dataset, and their performance is comparable with the white-box (physical) models.
elative controllability of nonlinear neutral Volterra Integrodiferential ...
African Journals Online (AJOL)
In this paper we established sufficient conditions for the relative controllability of the nonlinear neutral volterra integro-differential systems with distributed delays in the control. The results were established using the Schauder's fixed point theorem which is an extension of known results. Journal of the Nigerian Association of ...
International Nuclear Information System (INIS)
Bogolyubov, N.P.
1988-01-01
A model of the spontaneous breaking of chiral symmetry motivated by quantum chromodynamics is considered at a finite density of the quarks and zero temperature. For zero chemical potential the dynamical quark mass, the bag constant, and the vacuum expectation value are estimated. The dependence of the grand thermodynamic potential on the chemical potential of the quarks and of the energy on the particle number density are calculated. It is found that there is a phase transition of the first kind with respect to the density of the quarks accompanied by restoration of the chiral symmetry. The critical values of the fermion density are found
On chaos in Lotka–Volterra systems: an analytical approach
International Nuclear Information System (INIS)
Kozlov, Vladimir; Vakulenko, Sergey
2013-01-01
In this paper, we study Lotka–Volterra systems with N species and n resources. We show that the long time dynamics of these systems may be complicated. Depending on parameter choice, they can generate all types of hyperbolic dynamics, in particular, chaotic ones. Moreover, Lotka–Volterra systems can generate Lorenz dynamics. We state the conditions on the strong persistence of Lotka–Volterra systems when the number of resources is less than the number of species. (paper)
[Generalization of the Lotka-Volterra equation].
Nazarenko, V G
1976-01-01
A complete qualitative study of Lotka--Volterra model with cooperative interactions in the system predator-prey is carried out. The model is as follows: (see abstract). The character of all possible stationary states is investigated in the first quadrant of the phase plane of the model variables depending on the system parameters. It is shown that for the generalized model considered unstable and stable limit cycles only of the infinite amplitude are possible in the first quadrant.
Calculation of Volterra kernels for solutions of nonlinear differential equations
van Hemmen, JL; Kistler, WM; Thomas, EGF
2000-01-01
We consider vector-valued autonomous differential equations of the form x' = f(x) + phi with analytic f and investigate the nonanticipative solution operator phi bar right arrow A(phi) in terms of its Volterra series. We show that Volterra kernels of order > 1 occurring in the series expansion of
Algebraic features of some generalizations of the Lotka-Volterra system
Bibik, Yu. V.; Sarancha, D. A.
2010-10-01
For generalizations of the Lotka-Volterra system, an integration method is proposed based on the nontrivial algebraic structure of these generalizations. The method makes use of an auxiliary first-order differential equation derived from the phase curve equation with the help of this algebraic structure. Based on this equation, a Hamiltonian approach can be developed and canonical variables (moreover, action-angle variables) can be constructed.
Multi-Hamiltonian structure of Lotka-Volterra and quantum Volterra models
International Nuclear Information System (INIS)
Cronstroem, C.; Noga, M.
1995-01-01
We consider evolution equations of the Lotka-Volterra type, and elucidate especially their formulation as canonical Hamiltonian systems. The general conditions under which these equations admit several conserved quantities (multi-Hamiltonians) are analysed. A special case, which is related to the Liouville model on a lattice, is considered in detail, both as a classical and as a quantum system. (orig.)
Reduced Complexity Volterra Models for Nonlinear System Identification
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Hacıoğlu Rıfat
2001-01-01
Full Text Available A broad class of nonlinear systems and filters can be modeled by the Volterra series representation. However, its practical use in nonlinear system identification is sometimes limited due to the large number of parameters associated with the Volterra filter′s structure. The parametric complexity also complicates design procedures based upon such a model. This limitation for system identification is addressed in this paper using a Fixed Pole Expansion Technique (FPET within the Volterra model structure. The FPET approach employs orthonormal basis functions derived from fixed (real or complex pole locations to expand the Volterra kernels and reduce the number of estimated parameters. That the performance of FPET can considerably reduce the number of estimated parameters is demonstrated by a digital satellite channel example in which we use the proposed method to identify the channel dynamics. Furthermore, a gradient-descent procedure that adaptively selects the pole locations in the FPET structure is developed in the paper.
Ecological communities with Lotka-Volterra dynamics
Bunin, Guy
2017-04-01
Ecological communities in heterogeneous environments assemble through the combined effect of species interaction and migration. Understanding the effect of these processes on the community properties is central to ecology. Here we study these processes for a single community subject to migration from a pool of species, with population dynamics described by the generalized Lotka-Volterra equations. We derive exact results for the phase diagram describing the dynamical behaviors, and for the diversity and species abundance distributions. A phase transition is found from a phase where a unique globally attractive fixed point exists to a phase where multiple dynamical attractors exist, leading to history-dependent community properties. The model is shown to possess a symmetry that also establishes a connection with other well-known models.
Hamiltonian structure of the Lotka-Volterra equations
Nutku, Y.
1990-03-01
The Lotka-Volterra equations governing predator-prey relations are shown to admit Hamiltonian structure with respect to a generalized Poisson bracket. These equations provide an example of a system for which the naive criterion for the existence of Hamiltonian structure fails. We show further that there is a three-component generalization of the Lotka-Volterra equations which is a bi-Hamiltonian system.
Lattice defects as Lotka-Volterra societies
Energy Technology Data Exchange (ETDEWEB)
Yost, F.G.
1995-07-01
Since the early part of this century the Lotka-Volterra or predator-prey equations have been known to simulate the stability, instability, and persistent oscillations observed in many biological and ecological societies. These equations have been modified in many ways and have been used to model phenomena as varied as childhood epidemics, enzyme reactions, and conventional warfare. In the work to be described, similarities are drawn between various lattice defects and Lotka-Volterra (LV) societies. Indeed, grain boundaries are known to ``consume`` dislocations, inclusions ``infect`` grain boundaries, and dislocations ``annihilate`` dislocations. Several specific cases of lattice defect interaction kinetics models are drawn from the materials science literature to make these comparisons. Each model will be interpreted as if it were a description of a biological system. Various approaches to the modification of this class of interaction kinetics will be presented and discussed. The earliest example is the Damask-Dienes treatment of vacancy-divacancy annealing kinetics. This historical model will be modified to include the effects of an intermediate species and the results will be compared with the original model. The second example to be examined is the Clark-Alden model for deformation-enhanced grain growth. Dislocation kinetics will be added to this model and results will be discussed considering the original model. The third example to be presented is the Ananthakrishna-Sahoo model of the Portevin-Le Chatelier effect that was offered in 1985 as an extension of the classical Cottrell atmosphere explanation. Their treatment will be modified by inclusion of random interference from a pesky but peripheral species and by allowing a rate constant to be a function of time.
The matrix realization of affine Jacobi varieties and the extended Lotka-Volterra lattice
International Nuclear Information System (INIS)
Inoue, Rei
2004-01-01
We study completely integrable Hamiltonian systems whose monodromy matrices are related to the representatives for the set of gauge equivalence classes M F of polynomial matrices. Let X be the algebraic curve given by the common characteristic equation for M F . We construct the isomorphism from the set of representatives to an affine part of the Jacobi variety of X. This variety corresponds to the invariant manifold of the system, where the Hamiltonian flow is linearized. As an application, we discuss the algebraic complete integrability of the extended Lotka-Volterra lattice with a periodic boundary condition
Feshchenko, R. M.; Vinogradov, A. V.; Artyukov, I. A.
2018-04-01
Using the method of Laplace transform the field amplitude in the paraxial approximation is found in the two-dimensional free space using initial values of the amplitude specified on an arbitrary shaped monotonic curve. The obtained amplitude depends on one a priori unknown function, which can be found from a Volterra first kind integral equation. In a special case of field amplitude specified on a concave parabolic curve the exact solution is derived. Both solutions can be used to study the light propagation from arbitrary surfaces including grazing incidence X-ray mirrors. They can find applications in the analysis of coherent imaging problems of X-ray optics, in phase retrieval algorithms as well as in inverse problems in the cases when the initial field amplitude is sought on a curved surface.
Directory of Open Access Journals (Sweden)
Ali Konuralp
2014-01-01
Full Text Available Application process of variational iteration method is presented in order to solve the Volterra functional integrodifferential equations which have multi terms and vanishing delays where the delay function θ(t vanishes inside the integral limits such that θ(t=qt for 0
Representation of neural networks as Lotka-Volterra systems
International Nuclear Information System (INIS)
Moreau, Yves; Vandewalle, Joos; Louies, Stephane; Brenig, Leon
1999-01-01
We study changes of coordinates that allow the representation of the ordinary differential equations describing continuous-time recurrent neural networks into differential equations describing predator-prey models--also called Lotka-Volterra systems. We transform the equations for the neural network first into quasi-monomial form, where we express the vector field of the dynamical system as a linear combination of products of powers of the variables. In practice, this transformation is possible only if the activation function is the hyperbolic tangent or the logistic sigmoied. From this quasi-monomial form, we can directly transform the system further into Lotka-Volterra equations. The resulting Lotka-Volterra system is of higher dimension than the original system, but the behavior of its first variables is equivalent to the behavior of the original neural network
International Nuclear Information System (INIS)
Yuste, Santos Bravo; Abad, Enrique
2011-01-01
We present an iterative method to obtain approximations to Bessel functions of the first kind J p (x) (p > -1) via the repeated application of an integral operator to an initial seed function f 0 (x). The class of seed functions f 0 (x) leading to sets of increasingly accurate approximations f n (x) is considerably large and includes any polynomial. When the operator is applied once to a polynomial of degree s, it yields a polynomial of degree s + 2, and so the iteration of this operator generates sets of increasingly better polynomial approximations of increasing degree. We focus on the set of polynomial approximations generated from the seed function f 0 (x) = 1. This set of polynomials is useful not only for the computation of J p (x) but also from a physical point of view, as it describes the long-time decay modes of certain fractional diffusion and diffusion-wave problems.
Continuous multistep methods for volterra integro-differential ...
African Journals Online (AJOL)
A new class of numerical methods for Volterra integro-differential equations of the second order is developed. The methods are based on interpolation and collocation of the shifted Legendre polynomial as basis function with Trapezoidal quadrature rules. The convergence analysis revealed that the methods are consistent ...
Evolution of Black-Box Models Based on Volterra Series
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Daniel D. Silveira
2015-01-01
Full Text Available This paper presents a historical review of the many behavioral models actually used to model radio frequency power amplifiers and a new classification of these behavioral models. It also discusses the evolution of these models, from a single polynomial to multirate Volterra models, presenting equations and estimation methods. New trends in RF power amplifier behavioral modeling are suggested.
Transcendental smallness in singularly perturbed equations of volterra type
International Nuclear Information System (INIS)
Bijura, Angelina M.
2003-11-01
The application of different limit processes to a physical problem is an important tool in layer type techniques. Hence the study of initial layer correction functions is of central importance for understanding layer-type problems. It is shown that for singularly perturbed problems of Volterra type, the concept of transcendental smallness is an asymptotic one. Transcendentally small terms may be numerically important. (author)
Initial layer theory and model equations of Volterra type
International Nuclear Information System (INIS)
Bijura, Angelina M.
2003-10-01
It is demonstrated here that there exist initial layers to singularly perturbed Volterra equations whose thicknesses are not of order of magnitude of 0(ε), ε → 0. It is also shown that the initial layer theory is extremely useful because it allows one to construct the approximate solution to an equation, which is almost identical to the exact solution. (author)
A Lotka-Volterra competition model with seasonal succession.
Hsu, Sze-Bi; Zhao, Xiao-Qiang
2012-01-01
A complete classification for the global dynamics of a Lotka-Volterra two species competition model with seasonal succession is obtained via the stability analysis of equilibria and the theory of monotone dynamical systems. The effects of two death rates in the bad season and the proportion of the good season on the competition outcomes are also discussed. © Springer-Verlag 2011
Invariants for the generalized Lotka-Volterra equations
Cairó, Laurent; Feix, Marc R.; Goedert, Joao
A generalisation of Lotka-Volterra System is given when self limiting terms are introduced in the model. We use a modification of the Carleman embedding method to find invariants for this system of equations. The position and stability of the equilibrium point and the regression of system under invariant conditions are studied.
A simple spatiotemporal chaotic Lotka-Volterra model
International Nuclear Information System (INIS)
Sprott, J.C.; Wildenberg, J.C.; Azizi, Yousef
2005-01-01
A mathematically simple example of a high-dimensional (many-species) Lotka-Volterra model that exhibits spatiotemporal chaos in one spatial dimension is described. The model consists of a closed ring of identical agents, each competing for fixed finite resources with two of its four nearest neighbors. The model is prototypical of more complicated models in its quasiperiodic route to chaos (including attracting 3-tori), bifurcations, spontaneous symmetry breaking, and spatial pattern formation
Turing patterns in a modified Lotka-Volterra model
International Nuclear Information System (INIS)
McGehee, Edward A.; Peacock-Lopez, Enrique
2005-01-01
In this Letter we consider a modified Lotka-Volterra model widely known as the Bazykin model, which is the MacArthur-Rosenzweig (MR) model that includes a prey-dependent response function and is modified with the inclusion of intraspecies interactions. We show that a quadratic intra-prey interaction term, which is the most realistic nonlinearity, yields sufficient conditions for Turing patterns. For the Bazykin model we find the Turing region in parameter space and Turing patterns in one dimension
Positive periodic solutions of delayed periodic Lotka-Volterra systems
International Nuclear Information System (INIS)
Lin Wei; Chen Tianping
2005-01-01
In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases
Lotka-Volterra representation of general nonlinear systems.
Hernández-Bermejo, B; Fairén, V
1997-02-01
In this article we elaborate on the structure of the generalized Lotka-Volterra (GLV) form for nonlinear differential equations. We discuss here the algebraic properties of the GLV family, such as the invariance under quasimonomial transformations and the underlying structure of classes of equivalence. Each class possesses a unique representative under the classical quadratic Lotka-Volterra form. We show how other standard modeling forms of biological interest, such as S-systems or mass-action systems, are naturally embedded into the GLV form, which thus provides a formal framework for their comparison and for the establishment of transformation rules. We also focus on the issue of recasting of general nonlinear systems into the GLV format. We present a procedure for doing so and point at possible sources of ambiguity that could make the resulting Lotka-Volterra system dependent on the path followed. We then provide some general theorems that define the operational and algorithmic framework in which this is not the case.
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Omar Abu Arqub
2012-01-01
Full Text Available This paper investigates the numerical solution of nonlinear Fredholm-Volterra integro-differential equations using reproducing kernel Hilbert space method. The solution ( is represented in the form of series in the reproducing kernel space. In the mean time, the n-term approximate solution ( is obtained and it is proved to converge to the exact solution (. Furthermore, the proposed method has an advantage that it is possible to pick any point in the interval of integration and as well the approximate solution and its derivative will be applicable. Numerical examples are included to demonstrate the accuracy and applicability of the presented technique. The results reveal that the method is very effective and simple.
On solutions of neutral stochastic delay Volterra equations with singular kernels
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Xiaotai Wu
2012-08-01
Full Text Available In this paper, existence, uniqueness and continuity of the adapted solutions for neutral stochastic delay Volterra equations with singular kernels are discussed. In addition, continuous dependence on the initial date is also investigated. Finally, stochastic Volterra equation with the kernel of fractional Brownian motion is studied to illustrate the effectiveness of our results.
DEFF Research Database (Denmark)
Chon, K H; Holstein-Rathlou, N H; Marsh, D J
1998-01-01
kernel estimation method based on Laguerre expansions. The results for the two types of artificial neural networks and the Volterra models are comparable in terms of normalized mean square error (NMSE) of the respective output prediction for independent testing data. However, the Volterra models obtained...
Volterra integral equation-factorisation method and nucleus ...
Indian Academy of Sciences (India)
U LAHA
1Department of Physics, National Institute of Technology, Jamshedpur 831 014, India. 2Department of Physics ... published online 28 February 2018. Abstract. ... Woods–Saxon [11], Gaussian [12], energy-dependent. [13] and so on.
Handbook of integral equations
Polyanin, Andrei D
2008-01-01
This handbook contains over 2,500 integral equations with solutions as well as analytical and numerical methods for solving linear and nonlinear equations. It explores Volterra, Fredholm, WienerHopf, Hammerstein, Uryson, and other equations that arise in mathematics, physics, engineering, the sciences, and economics. This second edition includes new chapters on mixed multidimensional equations and methods of integral equations for ODEs and PDEs, along with over 400 new equations with exact solutions. With many examples added for illustrative purposes, it presents new material on Volterra, Fredholm, singular, hypersingular, dual, and nonlinear integral equations, integral transforms, and special functions.
Coexistence and Survival in Conservative Lotka-Volterra Networks
Knebel, Johannes; Krüger, Torben; Weber, Markus F.; Frey, Erwin
2013-04-01
Analyzing coexistence and survival scenarios of Lotka-Volterra (LV) networks in which the total biomass is conserved is of vital importance for the characterization of long-term dynamics of ecological communities. Here, we introduce a classification scheme for coexistence scenarios in these conservative LV models and quantify the extinction process by employing the Pfaffian of the network’s interaction matrix. We illustrate our findings on global stability properties for general systems of four and five species and find a generalized scaling law for the extinction time.
String networks in ZN Lotka–Volterra competition models
International Nuclear Information System (INIS)
Avelino, P.P.; Bazeia, D.; Menezes, J.; Oliveira, B.F. de
2014-01-01
In this Letter we give specific examples of Z N Lotka–Volterra competition models leading to the formation of string networks. We show that, in order to promote coexistence, the species may arrange themselves around regions with a high number density of empty sites generated by predator–prey interactions between competing species. These configurations extend into the third dimension giving rise to string networks. We investigate the corresponding dynamics using both stochastic and mean field theory simulations, showing that the coarsening of these string networks follows a scaling law which is analogous to that found in other physical systems in condensed matter and cosmology
Volterra model and quark hadronization into multicomponent hadron system
International Nuclear Information System (INIS)
Darbaidze, Ya.Z.; Rostovtsev, V.A.
1989-01-01
The examples of the multiparticle process characteristic dependence on the number of a low correlated components are considered. The possibility for reducing the differential equation system, which was obtained earlier, to a dissipative type Volterra model of competing biological species for the same food is discussed. An algorithm for the analytical computation of the high order differential equation as a resultant of the of the arising system is given. The examples of linearization and solution of these equations describing the associated multiplicities of charge particles are represented. 25 refs.; 1 tab
Definite Integrals using Orthogonality and Integral Transforms
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Howard S. Cohl
2012-10-01
Full Text Available We obtain definite integrals for products of associated Legendre functions with Bessel functions, associated Legendre functions, and Chebyshev polynomials of the first kind using orthogonality and integral transforms.
Lotka-Volterra competition models for sessile organisms.
Spencer, Matthew; Tanner, Jason E
2008-04-01
Markov models are widely used to describe the dynamics of communities of sessile organisms, because they are easily fitted to field data and provide a rich set of analytical tools. In typical ecological applications, at any point in time, each point in space is in one of a finite set of states (e.g., species, empty space). The models aim to describe the probabilities of transitions between states. In most Markov models for communities, these transition probabilities are assumed to be independent of state abundances. This assumption is often suspected to be false and is rarely justified explicitly. Here, we start with simple assumptions about the interactions among sessile organisms and derive a model in which transition probabilities depend on the abundance of destination states. This model is formulated in continuous time and is equivalent to a Lotka-Volterra competition model. We fit this model and a variety of alternatives in which transition probabilities do not depend on state abundances to a long-term coral reef data set. The Lotka-Volterra model describes the data much better than all models we consider other than a saturated model (a model with a separate parameter for each transition at each time interval, which by definition fits the data perfectly). Our approach provides a basis for further development of stochastic models of sessile communities, and many of the methods we use are relevant to other types of community. We discuss possible extensions to spatially explicit models.
Volterra equalization of complex modulation utilizing frequency chirp in directly modulated lasers
Hu, Shaohua; Yi, Xingwen; Zhang, Jing; Song, Yang; Zhu, Mingyue; Qiu, Kun
2018-02-01
We apply Volterra-based equalization for complex modulated optical signals utilizing the frequency chirp in DMLs. We experimentally demonstrate that the higher order Volterra filter is necessary in the higher speed transmissions. For further study, we isolate the adiabatic chirp by injection locking and realize the optical PM transmission. We make a comparison among IM, FM and PM with Volterra equalization, finding that PM and FM are more power insensitive and suitable for high speed, power limited fiber transmission. The performance can be further improved by exploiting the diversity gain.
SOLVING FRACTIONAL-ORDER COMPETITIVE LOTKA-VOLTERRA MODEL BY NSFD SCHEMES
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S.ZIBAEI
2016-12-01
Full Text Available In this paper, we introduce fractional-order into a model competitive Lotka- Volterra prey-predator system. We will discuss the stability analysis of this fractional system. The non-standard nite difference (NSFD scheme is implemented to study the dynamic behaviors in the fractional-order Lotka-Volterra system. Proposed non-standard numerical scheme is compared with the forward Euler and fourth order Runge-Kutta methods. Numerical results show that the NSFD approach is easy and accurate for implementing when applied to fractional-order Lotka-Volterra model.
An equivalent condition for stability properties of Lotka-Volterra systems
International Nuclear Information System (INIS)
Chu Tianguang
2007-01-01
We give a solvable Lie algebraic condition for the equivalence of four typical stability notions (asymptotic stability, D-stability, total stability, and Volterra-Lyapunov stability) concerning Lotka-Volterra systems. Our approach makes use of the decomposition of the interaction matrix into symmetric and skew-symmetric parts, which may be related to the cooperative and competitive interaction pattern of a Lotka-Volterra system. The present result covers a known condition and can yield a larger set of interaction matrices for equivalence of the stability properties
Kan-On, Yukio
2007-04-01
This paper is concerned with the bifurcation structure of positive stationary solutions for a generalized Lotka-Volterra competition model with diffusion. To establish the structure, the bifurcation theory and the interval arithmetic are employed.
The cyclicity of period annulus of a quadratic reversible Lotka–Volterra system
International Nuclear Information System (INIS)
Li, Chengzhi; Llibre, Jaume
2009-01-01
We prove that by perturbing the periodic annulus of the quadratic polynomial reversible Lotka–Volterra differential system, inside the class of all quadratic polynomial differential systems we can obtain at most two limit cycles
Stationary Response of Lotka—Volterra System with Real Noises
International Nuclear Information System (INIS)
Qi Lu-Yuan; Xu Wei; Gao Wei-Ting
2013-01-01
A stochastic version of Lotka—Volterra model subjected to real noises is proposed and investigated. The approximate stationary probability densities for both predator and prey are obtained analytically. The original system is firstly transformed to a pair of Itô stochastic differential equations. The Itô formula is then carried out to obtain the Itô stochastic differential equation for the period orbit function. The orbit function is considered as slowly varying process under reasonable assumptions. By applying the stochastic averaging method to the orbit function in one period, the averaged Itô stochastic differential equation of the motion orbit and the corresponding Fokker—Planck equation are derived. The probability density functions of the two species are thus formulated. Finally, a classical real noise model is given as an example to show the proposed approximate method. The accuracy of the proposed procedure is verified by Monte Carlo simulation. (interdisciplinary physics and related areas of science and technology)
Lie Symmetry of the Diffusive Lotka–Volterra System with Time-Dependent Coefficients
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Vasyl’ Davydovych
2018-02-01
Full Text Available Lie symmetry classification of the diffusive Lotka–Volterra system with time-dependent coefficients in the case of a single space variable is studied. A set of such symmetries in an explicit form is constructed. A nontrivial ansatz reducing the Lotka–Volterra system with correctly-specified coefficients to the system of ordinary differential equations (ODEs and an example of the exact solution with a biological interpretation are found.
On the Restriction of the Location of Stable Points for Generalized Lotka-Volterra
Livesay, Michael Richard
2017-01-01
We develop tools to determine which fixed points in a generalized Lotka-Volterra system are stable, under certain non-degeneracy conditions. We characterize which faces of the boundary of the domain of the Lotka-Volterra system could contain a stable fixed point. Under various relaxed conditions, we show that whenever a face of the boundary contains a stable point there are no other stable points in any strictly larger face of the boundary.
An integrating factor matrix method to find first integrals
International Nuclear Information System (INIS)
Saputra, K V I; Quispel, G R W; Van Veen, L
2010-01-01
In this paper we develop an integrating factor matrix method to derive conditions for the existence of first integrals. We use this novel method to obtain first integrals, along with the conditions for their existence, for two- and three-dimensional Lotka-Volterra systems with constant terms. The results are compared to previous results obtained by other methods.
Lotka-Volterra systems in environments with randomly disordered temporal periodicity
Naess, Arvid; Dimentberg, Michael F.; Gaidai, Oleg
2008-08-01
A generalized Lotka-Volterra model for a pair of interacting populations of predators and prey is studied. The model accounts for the prey’s interspecies competition and therefore is asymptotically stable, whereas its oscillatory behavior is induced by temporal variations in environmental conditions simulated by those in the prey’s reproduction rate. Two models of the variations are considered, each of them combining randomness with “hidden” periodicity. The stationary joint probability density function (PDF) of the number of predators and prey is calculated numerically by the path integration (PI) method based on the use of characteristic functions and the fast Fourier transform. The numerical results match those for the asymptotic case of white-noise variations for which an analytical solution is available. Several examples are studied, with calculations of important characteristics of oscillations, for example the expected rate of up-crossings given the level of the predator number. The calculated PDFs may be of predominantly random (unimodal) or predominantly periodic nature (bimodal). Thus, the PI method has been demonstrated to be a powerful tool for studies of the dynamics of predator-prey pairs. The method captures the random oscillations as observed in nature, taking into account potential periodicity in the environmental conditions.
HOC Based Blind Identification of Hydroturbine Shaft Volterra System
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Bing Bai
2017-01-01
Full Text Available In order to identify the quadratic Volterra system simplified from the hydroturbine shaft system, a blind identification method based on the third-order cumulants and a reversely recursive method are proposed. The input sequence of the system under consideration is an unobservable independent identically distributed (i.i.d., zero-mean and non-Gaussian stationary signal, and the observed signals are the superposition of the system output signal and Gaussian noise. To calculate the third-order moment of the output signal, a computer loop judgment method is put forward to determine the coefficient. When using optimization method to identify the time domain kernels, we combined the traditional optimization algorithm (direct search method with genetic algorithm (GA and constituted the hybrid genetic algorithm (HGA. Finally, according to the prototype observation signal and the time domain kernel parameters obtained from identification, the input signal of the system can be gained recursively. To test the proposed method, three numerical experiments and engineering application have been carried out. The results show that the method is applicable to the blind identification of the hydroturbine shaft system and has strong universality; the input signal obtained by the reversely recursive method can be approximately taken as the random excitation acted on the runner of the hydroturbine shaft system.
Food Web Assembly Rules for Generalized Lotka-Volterra Equations.
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Jan O Haerter
2016-02-01
Full Text Available In food webs, many interacting species coexist despite the restrictions imposed by the competitive exclusion principle and apparent competition. For the generalized Lotka-Volterra equations, sustainable coexistence necessitates nonzero determinant of the interaction matrix. Here we show that this requirement is equivalent to demanding that each species be part of a non-overlapping pairing, which substantially constrains the food web structure. We demonstrate that a stable food web can always be obtained if a non-overlapping pairing exists. If it does not, the matrix rank can be used to quantify the lack of niches, corresponding to unpaired species. For the species richness at each trophic level, we derive the food web assembly rules, which specify sustainable combinations. In neighboring levels, these rules allow the higher level to avert competitive exclusion at the lower, thereby incorporating apparent competition. In agreement with data, the assembly rules predict high species numbers at intermediate levels and thinning at the top and bottom. Using comprehensive food web data, we demonstrate how omnivores or parasites with hosts at multiple trophic levels can loosen the constraints and help obtain coexistence in food webs. Hence, omnivory may be the glue that keeps communities intact even under extinction or ecological release of species.
Food Web Assembly Rules for Generalized Lotka-Volterra Equations.
Haerter, Jan O; Mitarai, Namiko; Sneppen, Kim
2016-02-01
In food webs, many interacting species coexist despite the restrictions imposed by the competitive exclusion principle and apparent competition. For the generalized Lotka-Volterra equations, sustainable coexistence necessitates nonzero determinant of the interaction matrix. Here we show that this requirement is equivalent to demanding that each species be part of a non-overlapping pairing, which substantially constrains the food web structure. We demonstrate that a stable food web can always be obtained if a non-overlapping pairing exists. If it does not, the matrix rank can be used to quantify the lack of niches, corresponding to unpaired species. For the species richness at each trophic level, we derive the food web assembly rules, which specify sustainable combinations. In neighboring levels, these rules allow the higher level to avert competitive exclusion at the lower, thereby incorporating apparent competition. In agreement with data, the assembly rules predict high species numbers at intermediate levels and thinning at the top and bottom. Using comprehensive food web data, we demonstrate how omnivores or parasites with hosts at multiple trophic levels can loosen the constraints and help obtain coexistence in food webs. Hence, omnivory may be the glue that keeps communities intact even under extinction or ecological release of species.
Extinction in neutrally stable stochastic Lotka-Volterra models
Dobrinevski, Alexander; Frey, Erwin
2012-05-01
Populations of competing biological species exhibit a fascinating interplay between the nonlinear dynamics of evolutionary selection forces and random fluctuations arising from the stochastic nature of the interactions. The processes leading to extinction of species, whose understanding is a key component in the study of evolution and biodiversity, are influenced by both of these factors. Here, we investigate a class of stochastic population dynamics models based on generalized Lotka-Volterra systems. In the case of neutral stability of the underlying deterministic model, the impact of intrinsic noise on the survival of species is dramatic: It destroys coexistence of interacting species on a time scale proportional to the population size. We introduce a new method based on stochastic averaging which allows one to understand this extinction process quantitatively by reduction to a lower-dimensional effective dynamics. This is performed analytically for two highly symmetrical models and can be generalized numerically to more complex situations. The extinction probability distributions and other quantities of interest we obtain show excellent agreement with simulations.
Lotka-Volterra system in a random environment
Dimentberg, Mikhail F.
2002-03-01
Classical Lotka-Volterra (LV) model for oscillatory behavior of population sizes of two interacting species (predator-prey or parasite-host pairs) is conservative. This may imply unrealistically high sensitivity of the system's behavior to environmental variations. Thus, a generalized LV model is considered with the equation for preys' reproduction containing the following additional terms: quadratic ``damping'' term that accounts for interspecies competition, and term with white-noise random variations of the preys' reproduction factor that simulates the environmental variations. An exact solution is obtained for the corresponding Fokker-Planck-Kolmogorov equation for stationary probability densities (PDF's) of the population sizes. It shows that both population sizes are independent γ-distributed stationary random processes. Increasing level of the environmental variations does not lead to extinction of the populations. However it may lead to an intermittent behavior, whereby one or both population sizes experience very rare and violent short pulses or outbreaks while remaining on a very low level most of the time. This intermittency is described analytically by direct use of the solutions for the PDF's as well as by applying theory of excursions of random functions and by predicting PDF of peaks in the predators' population size.
Verhulst-Lotka-Volterra (VLV) model of ideological struggle
Vitanov, Nikolay K.; Dimitrova, Zlatinka I.; Ausloos, Marcel
2010-11-01
A model for ideological struggles is formulated. The underlying set is a closed one, like a country but in which the population size is variable in time. The dynamics of the struggle is described by model equations of Verhulst-Lotka-Volterra kind. Several “ideologies” compete to increase their number of adepts. Such followers can be either converted from one ideology to another or become followers of an ideology though being previously ideologically-free. A reverse process is also allowed. Two kinds of conversions are considered: unitary conversion, e.g. by means of mass communication tools, or binary conversion, e.g. by means of interactions between people. It is found that the steady state, when it exists, depends on the number of ideologies. Moreover when the number of ideologies increases some tension arises between them. This tension can change in the course of time. We propose to measure the ideology tensions through an appropriately defined scale index. Finally it is shown that a slight change in the conditions of the environment can prevent the extinction of some ideology; after almost collapsing the ideology can spread again and can affect a significant part of the country’s population. Two kinds of such resurrection effects are described as phoenix effects.
Security analysis of chaotic communication systems based on Volterra-Wiener-Korenberg model
International Nuclear Information System (INIS)
Lei Min; Meng Guang; Feng Zhengjin
2006-01-01
Pseudo-randomicity is an important cryptological characteristic for proof of encryption algorithms. This paper proposes a nonlinear detecting method based on Volterra-Wiener-Korenberg model and suggests an autocorrelation function to analyze the pseudo-randomicity of chaotic secure systems under different sampling interval. The results show that: (1) the increase of the order of the chaotic transmitter will not necessarily result in a high degree of security; (2) chaotic secure systems have higher and stronger pseudo-randomicity at sparse sampling interval due to the similarity of chaotic time series to the noise; (3) Volterra-Wiener-Korenberg method can also give a further appropriate sparse sampling interval for improving the security of chaotic secure communication systems. For unmasking chaotic communication systems, the Volterra-Wiener-Korenberg technique can be applied to analyze the chaotic time series with surrogate data
Three-dimensional discrete-time Lotka-Volterra models with an application to industrial clusters
Bischi, G. I.; Tramontana, F.
2010-10-01
We consider a three-dimensional discrete dynamical system that describes an application to economics of a generalization of the Lotka-Volterra prey-predator model. The dynamic model proposed is used to describe the interactions among industrial clusters (or districts), following a suggestion given by [23]. After studying some local and global properties and bifurcations in bidimensional Lotka-Volterra maps, by numerical explorations we show how some of them can be extended to their three-dimensional counterparts, even if their analytic and geometric characterization becomes much more difficult and challenging. We also show a global bifurcation of the three-dimensional system that has no two-dimensional analogue. Besides the particular economic application considered, the study of the discrete version of Lotka-Volterra dynamical systems turns out to be a quite rich and interesting topic by itself, i.e. from a purely mathematical point of view.
The Jungle Universe: coupled cosmological models in a Lotka-Volterra framework
Perez, Jérôme; Füzfa, André; Carletti, Timoteo; Mélot, Laurence; Guedezounme, Lazare
2014-06-01
In this paper, we exploit the fact that the dynamics of homogeneous and isotropic Friedmann-Lemaître universes is a special case of generalized Lotka-Volterra system where the competitive species are the barotropic fluids filling the Universe. Without coupling between those fluids, Lotka-Volterra formulation offers a pedagogical and simple way to interpret usual Friedmann-Lemaître cosmological dynamics. A natural and physical coupling between cosmological fluids is proposed which preserves the structure of the dynamical equations. Using the standard tools of Lotka-Volterra dynamics, we obtain the general Lyapunov function of the system when one of the fluids is coupled to dark energy. This provides in a rigorous form a generic asymptotic behavior for cosmic expansion in presence of coupled species, beyond the standard de Sitter, Einstein-de Sitter and Milne cosmologies. Finally, we conjecture that chaos can appear for at least four interacting fluids.
Nonlinear System Identification via Basis Functions Based Time Domain Volterra Model
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Yazid Edwar
2014-07-01
Full Text Available This paper proposes basis functions based time domain Volterra model for nonlinear system identification. The Volterra kernels are expanded by using complex exponential basis functions and estimated via genetic algorithm (GA. The accuracy and practicability of the proposed method are then assessed experimentally from a scaled 1:100 model of a prototype truss spar platform. Identification results in time and frequency domain are presented and coherent functions are performed to check the quality of the identification results. It is shown that results between experimental data and proposed method are in good agreement.
Hamiltonian structure and Darboux theorem for families of generalized Lotka-Volterra systems
Hernández-Bermejo, Benito; Fairén, Víctor
1998-11-01
This work is devoted to the establishment of a Poisson structure for a format of equations known as generalized Lotka-Volterra systems. These equations, which include the classical Lotka-Volterra systems as a particular case, have been deeply studied in the literature. They have been shown to constitute a whole hierarchy of systems, the characterization of which is made in the context of simple algebra. Our main result is to show that this algebraic structure is completely translatable into the Poisson domain. Important Poisson structures features, such as the symplectic foliation and the Darboux canonical representation, rise as a result of rather simple matrix manipulations.
Qualitative aspects of Volterra integro-dynamic system on time scales
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Vasile Lupulescu
2013-01-01
Full Text Available This paper deals with the resolvent, asymptotic stability and boundedness of the solution of time-varying Volterra integro-dynamic system on time scales in which the coefficient matrix is not necessarily stable. We generalize at time scale some known properties about asymptotic behavior and boundedness from the continuous case. Some new results for discrete case are obtained.
A Volterra series approach to the approximation of stochastic nonlinear dynamics
Wouw, van de N.; Nijmeijer, H.; Campen, van D.H.
2002-01-01
A response approximation method for stochastically excited, nonlinear, dynamic systems is presented. Herein, the output of the nonlinear system isapproximated by a finite-order Volterra series. The original nonlinear system is replaced by a bilinear system in order to determine the kernels of this
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Xinggui Liu
2011-01-01
Full Text Available In this paper, by using Mawhin's continuation theorem of coincidence degree theory, we establish the existence of at least four positive periodic solutions for a discrete time Lotka-Volterra competitive system with harvesting terms. An example is given to illustrate the effectiveness of our results.
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John A. D. Appleby
2008-01-01
Full Text Available This paper considers necessary and sufficient conditions for the solution of a stochastically and deterministically perturbed Volterra equation to converge exponentially to a nonequilibrium and nontrivial limit. Convergence in an almost sure and pth mean sense is obtained.
Neural network modeling of nonlinear systems based on Volterra series extension of a linear model
Soloway, Donald I.; Bialasiewicz, Jan T.
1992-01-01
A Volterra series approach was applied to the identification of nonlinear systems which are described by a neural network model. A procedure is outlined by which a mathematical model can be developed from experimental data obtained from the network structure. Applications of the results to the control of robotic systems are discussed.
International Nuclear Information System (INIS)
Cai, Zuowei; Huang, Lihong
2013-01-01
Highlights: • A more practical form of harvesting management policy (DHP) has been proposed. • We analyze the periodic dynamics of a class of discontinuous and delayed Lotka–Volterra competition systems. • We present a new method to obtain the existence of positive periodic solutions via differential inclusions. • The global convergence in measure of harvesting solution is discussed. -- Abstract: This paper considers a general class of delayed Lotka–Volterra competition systems where the harvesting policies are modeled by discontinuous functions or by non-Lipschitz functions. By means of differential inclusions theory, cone expansion and compression fixed point theorem of multi-valued maps and nonsmooth analysis theory with generalized Lyapunov approach, a series of useful criteria on existence, uniqueness and global asymptotic stability of the positive periodic solution is established for the delayed Lotka–Volterra competition systems with discontinuous right-hand sides. Moreover, the global convergence in measure of harvesting solution is discussed. Our results improve and extend previous works on periodic dynamics of delayed Lotka–Volterra competition systems with not only continuous or even Lipschitz continuous but also discontinuous harvesting functions. Finally, we give some corollaries and numerical examples to show the applicability and effectiveness of the proposed criteria
Laamiri, Imen; Khouaja, Anis; Messaoud, Hassani
2015-03-01
In this paper we provide a convergence analysis of the alternating RGLS (Recursive Generalized Least Square) algorithm used for the identification of the reduced complexity Volterra model describing stochastic non-linear systems. The reduced Volterra model used is the 3rd order SVD-PARAFC-Volterra model provided using the Singular Value Decomposition (SVD) and the Parallel Factor (PARAFAC) tensor decomposition of the quadratic and the cubic kernels respectively of the classical Volterra model. The Alternating RGLS (ARGLS) algorithm consists on the execution of the classical RGLS algorithm in alternating way. The ARGLS convergence was proved using the Ordinary Differential Equation (ODE) method. It is noted that the algorithm convergence canno׳t be ensured when the disturbance acting on the system to be identified has specific features. The ARGLS algorithm is tested in simulations on a numerical example by satisfying the determined convergence conditions. To raise the elegies of the proposed algorithm, we proceed to its comparison with the classical Alternating Recursive Least Squares (ARLS) presented in the literature. The comparison has been built on a non-linear satellite channel and a benchmark system CSTR (Continuous Stirred Tank Reactor). Moreover the efficiency of the proposed identification approach is proved on an experimental Communicating Two Tank system (CTTS). Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.
New stability and boundedness results to Volterra integro-differential equations with delay
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Cemil Tunç
2016-04-01
Full Text Available In this paper, we consider a certain non-linear Volterra integro-differential equations with delay. We study stability and boundedness of solutions. The technique of proof involves defining suitable Lyapunov functionals. Our results improve and extend the results obtained in literature.
Nonlinear Delay Discrete Inequalities and Their Applications to Volterra Type Difference Equations
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Yu Wu
2010-01-01
Full Text Available Delay discrete inequalities with more than one nonlinear term are discussed, which generalize some known results and can be used in the analysis of various problems in the theory of certain classes of discrete equations. Application examples to show boundedness and uniqueness of solutions of a Volterra type difference equation are also given.
Global asymptotic stability for a nonautonomous Lotka-Volterra competition system
TANIGUCHI, Kunihiko
2014-01-01
We consider nonautonomous N-dimensional generalized Lotka-Volterra competition systems. Under certain conditions we show that there exists a unique solution u* whose components are bounded above and below by positive constants on R, and u* attracts any solution. If such system is periodic, so is u*.
A Two-Species Cooperative Lotka-Volterra System of Degenerate Parabolic Equations
Sun, Jiebao; Zhang, Dazhi; Wu, Boying
2011-01-01
We consider a cooperating two-species Lotka-Volterra model of degenerate parabolic equations. We are interested in the coexistence of the species in a bounded domain. We establish the existence of global generalized solutions of the initial boundary value problem by means of parabolic regularization and also consider the existence of the nontrivial time-periodic solution for this system.
Stability and Hopf bifurcations in a competitive Lotka-Volterra system with two delays
International Nuclear Information System (INIS)
Song Yongli; Han Maoan; Peng Yahong
2004-01-01
We consider a Lotka-Volterra competition system with two delays. We first investigate the stability of the positive equilibrium and the existence of Hopf bifurcations, and then using the normal form theory and center manifold argument, derive the explicit formulas which determine the stability, direction and other properties of bifurcating periodic solutions
International Nuclear Information System (INIS)
Sun Wen; Chen Shihua; Hong Zhiming; Wang Changping
2007-01-01
A two-species periodic competition Lotka-Volterra system with time delay and diffusion is investigated. Some sufficient conditions of the existence of positive periodic solution are established for the system by using the continuation theorem of coincidence degree theory
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Berenguer MI
2010-01-01
Full Text Available This paper deals with obtaining a numerical method in order to approximate the solution of the nonlinear Volterra integro-differential equation. We define, following a fixed-point approach, a sequence of functions which approximate the solution of this type of equation, due to some properties of certain biorthogonal systems for the Banach spaces and .
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V. Vijayakumar
2012-09-01
Full Text Available n this paper, we study the global existence of solutions for the initial value problems for Volterra-Fredholm type neutral impulsive functional integrodifferential equations. Using the Leray-Schauder's Alternative theorem, we derive conditions under which a solution exists globally. An application is provided to illustrate the theory.
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Appleby JohnAD
2010-01-01
Full Text Available We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. The result is considered both for a linear Volterra integrodifferential equation as well as for the delay logistic equation from population biology.
International Nuclear Information System (INIS)
Nakahara, Yasuaki; Ise, Takeharu; Kobayashi, Kensuke; Itoh, Yasuyuki
1975-12-01
A new method has been developed for numerical solution of a class of nonlinear Volterra integro-differential equations with quadratic nonlinearity. After dividing the domain of the variable into subintervals, piecewise approximations are applied in the subintervals. The equation is first integrated over a subinterval to obtain the piecewise equation, to which six approximate treatments are applied, i.e. fully explicit, fully implicit, Crank-Nicolson, linear interpolation, quadratic and cubic spline. The numerical solution at each time step is obtained directly as a positive root of the resulting algebraic quadratic equation. The point reactor kinetics with a ramp reactivity insertion, linear temperature feedback and delayed neutrons can be described by one of this type of nonlinear Volterra integro-differential equations. The algorithm is applied to the Argonne benchmark problem and a model problem for a fast reactor without delayed neutrons. The fully implicit method has been found to be unconditionally stable in the sense that it always gives the positive real roots. The cubic spline method is divergent, and the other four methods are intermediate in between. From the estimation of the stability, convergency, accuracy and CPU time, it is concluded that the Crank-Nicolson method is best, then the linear interpolation method comes closely next to it. Discussions are also made on the possibility of applying the algorithm to the fusion reactor kinetics in the form of a nonlinear partial differential equation. (auth.)
John A. D. Appleby
2010-01-01
We consider the rate of convergence to equilibrium of Volterra integrodifferential equations with infinite memory. We show that if the kernel of Volterra operator is regularly varying at infinity, and the initial history is regularly varying at minus infinity, then the rate of convergence to the equilibrium is regularly varying at infinity, and the exact pointwise rate of convergence can be determined in terms of the rate of decay of the kernel and the rate of growth of the initial history. ...
Valenza, Gaetano; Citi, Luca; Barbieri, Riccardo
2013-01-01
We report an exemplary study of instantaneous assessment of cardiovascular dynamics performed using point-process nonlinear models based on Laguerre expansion of the linear and nonlinear Wiener-Volterra kernels. As quantifiers, instantaneous measures such as high order spectral features and Lyapunov exponents can be estimated from a quadratic and cubic autoregressive formulation of the model first order moment, respectively. Here, these measures are evaluated on heartbeat series coming from 16 healthy subjects and 14 patients with Congestive Hearth Failure (CHF). Data were gathered from the on-line repository PhysioBank, which has been taken as landmark for testing nonlinear indices. Results show that the proposed nonlinear Laguerre-Volterra point-process methods are able to track the nonlinear and complex cardiovascular dynamics, distinguishing significantly between CHF and healthy heartbeat series.
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Cemil Tunç
2017-10-01
Full Text Available In this article, the authors obtain some clear assumptions for the asymptotic stability (AS and boundedness (B of solutions of non-linear retarded Volterra integro-differential equations (VIDEs of first order by constructing a new Lyapunov functional (LF. The results obtained are new and differ from those found in the literature, and they also contain and improve a result found in the literature under more less restrictive conditions. We establish an example and give a discussion to indicate the applicability of the weaker conditions obtained. We also employ MATLAB-Simulink to display the behaviors of the orbits of the (VIDEs considered. Keywords: Nonlinear, Volterra integro-differential equations, First order, Asymptotic stability, Boundedness, Lyapunov functional, MSC: 34D05, 34K20, 45J05
Global stability and pattern formation in a nonlocal diffusive Lotka-Volterra competition model
Ni, Wenjie; Shi, Junping; Wang, Mingxin
2018-06-01
A diffusive Lotka-Volterra competition model with nonlocal intraspecific and interspecific competition between species is formulated and analyzed. The nonlocal competition strength is assumed to be determined by a diffusion kernel function to model the movement pattern of the biological species. It is shown that when there is no nonlocal intraspecific competition, the dynamics properties of nonlocal diffusive competition problem are similar to those of classical diffusive Lotka-Volterra competition model regardless of the strength of nonlocal interspecific competition. Global stability of nonnegative constant equilibria are proved using Lyapunov or upper-lower solution methods. On the other hand, strong nonlocal intraspecific competition increases the system spatiotemporal dynamic complexity. For the weak competition case, the nonlocal diffusive competition model may possess nonconstant positive equilibria for some suitably large nonlocal intraspecific competition coefficients.
Geometry of carrying simplices of 3-species competitive Lotka–Volterra systems
International Nuclear Information System (INIS)
Baigent, Stephen
2013-01-01
We investigate the existence, uniqueness and Gaussian curvature of the invariant carrying simplices of 3 species autonomous totally competitive Lotka–Volterra systems. Explicit examples are given where the carrying simplex is convex or concave, but also where the curvature is not single-signed. Our method monitors the curvature of an evolving surface that converges uniformly to the carrying simplex, and generally relies on establishing that the Gaussian image of the evolving surface is confined to an invariant cone. We also discuss the relationship between the curvature of the carrying simplex near an interior fixed point and its Split Lyapunov stability. Finally we comment on extensions to general Lotka–Volterra systems that are not competitive. (paper)
The discrete hungry Lotka Volterra system and a new algorithm for computing matrix eigenvalues
Fukuda, Akiko; Ishiwata, Emiko; Iwasaki, Masashi; Nakamura, Yoshimasa
2009-01-01
The discrete hungry Lotka-Volterra (dhLV) system is a generalization of the discrete Lotka-Volterra (dLV) system which stands for a prey-predator model in mathematical biology. In this paper, we show that (1) some invariants exist which are expressed by dhLV variables and are independent from the discrete time and (2) a dhLV variable converges to some positive constant or zero as the discrete time becomes sufficiently large. Some characteristic polynomial is then factorized with the help of the dhLV system. The asymptotic behaviour of the dhLV system enables us to design an algorithm for computing complex eigenvalues of a certain band matrix.
Sharp conditions for global stability of Lotka-Volterra systems with distributed delays
Faria, Teresa
We give a criterion for the global attractivity of a positive equilibrium of n-dimensional non-autonomous Lotka-Volterra systems with distributed delays. For a class of autonomous Lotka-Volterra systems, we show that such a criterion is sharp, in the sense that it provides necessary and sufficient conditions for the global asymptotic stability independently of the choice of the delay functions. The global attractivity of positive equilibria is established by imposing a diagonal dominance of the instantaneous negative feedback terms, and relies on auxiliary results showing the boundedness of all positive solutions. The paper improves and generalizes known results in the literature, namely by considering systems with distributed delays rather than discrete delays.
Lie and conditional symmetries of the three-component diffusive Lotka–Volterra system
International Nuclear Information System (INIS)
Cherniha, Roman; Davydovych, Vasyl’
2013-01-01
Lie and Q-conditional symmetries of the classical three-component diffusive Lotka–Volterra system in the case of one space variable are studied. The group-classification problems for finding Lie symmetries and Q-conditional symmetries of the first type are completely solved. Notably, non-Lie symmetries (Q-conditional symmetry operators) for a multi-component nonlinear reaction–diffusion system are constructed for the first time. The results are compared with those derived for the two-component diffusive Lotka–Volterra system. The conditional symmetry obtained for the non-Lie reduction of the three-component system used for modeling competition between three species in population dynamics is applied and the relevant exact solutions are found. Particularly, the exact solution describing different scenarios of competition between three species is constructed. (paper)
Dynamical behaviors determined by the Lyapunov function in competitive Lotka-Volterra systems
Tang, Ying; Yuan, Ruoshi; Ma, Yian
2013-01-01
Dynamical behaviors of the competitive Lotka-Volterra system even for 3 species are not fully understood. In this paper, we study this problem from the perspective of the Lyapunov function. We construct explicitly the Lyapunov function using three examples of the competitive Lotka-Volterra system for the whole state space: (1) the general 2-species case, (2) a 3-species model, and (3) the model of May-Leonard. The basins of attraction for these examples are demonstrated, including cases with bistability and cyclical behavior. The first two examples are the generalized gradient system, where the energy dissipation may not follow the gradient of the Lyapunov function. In addition, under a new type of stochastic interpretation, the Lyapunov function also leads to the Boltzmann-Gibbs distribution on the final steady state when multiplicative noise is added.
Nonlinear features identified by Volterra series for damage detection in a buckled beam
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Shiki S. B.
2014-01-01
Full Text Available The present paper proposes a new index for damage detection based on nonlinear features extracted from prediction errors computed by multiple convolutions using the discrete-time Volterra series. A reference Volterra model is identified with data in the healthy condition and used for monitoring the system operating with linear or nonlinear behavior. When the system has some structural change, possibly associated with damage, the index metrics computed could give an alert to separate the linear and nonlinear contributions, besides provide a diagnostic about the structural state. To show the applicability of the method, an experimental test is performed using nonlinear vibration signals measured in a clamped buckled beam subject to different levels of force applied and with simulated damages through discontinuities inserted in the beam surface.
The discrete hungry Lotka–Volterra system and a new algorithm for computing matrix eigenvalues
International Nuclear Information System (INIS)
Fukuda, Akiko; Ishiwata, Emiko; Iwasaki, Masashi; Nakamura, Yoshimasa
2009-01-01
The discrete hungry Lotka–Volterra (dhLV) system is a generalization of the discrete Lotka–Volterra (dLV) system which stands for a prey–predator model in mathematical biology. In this paper, we show that (1) some invariants exist which are expressed by dhLV variables and are independent from the discrete time and (2) a dhLV variable converges to some positive constant or zero as the discrete time becomes sufficiently large. Some characteristic polynomial is then factorized with the help of the dhLV system. The asymptotic behaviour of the dhLV system enables us to design an algorithm for computing complex eigenvalues of a certain band matrix
Feng, Guang; Li, Hengjian; Dong, Jiwen; Chen, Xi; Yang, Huiru
2018-04-01
In this paper, we proposed a joint and collaborative representation with Volterra kernel convolution feature (JCRVK) for face recognition. Firstly, the candidate face images are divided into sub-blocks in the equal size. The blocks are extracted feature using the two-dimensional Voltera kernels discriminant analysis, which can better capture the discrimination information from the different faces. Next, the proposed joint and collaborative representation is employed to optimize and classify the local Volterra kernels features (JCR-VK) individually. JCR-VK is very efficiently for its implementation only depending on matrix multiplication. Finally, recognition is completed by using the majority voting principle. Extensive experiments on the Extended Yale B and AR face databases are conducted, and the results show that the proposed approach can outperform other recently presented similar dictionary algorithms on recognition accuracy.
Asymptotic Behaviour and Extinction of Delay Lotka-Volterra Model with Jump-Diffusion
Dan Li; Jing’an Cui; Guohua Song
2014-01-01
This paper studies the effect of jump-diffusion random environmental perturbations on the asymptotic behaviour and extinction of Lotka-Volterra population dynamics with delays. The contributions of this paper lie in the following: (a) to consider delay stochastic differential equation with jumps, we introduce a proper initial data space, in which the initial data may be discontinuous function with downward jumps; (b) we show that the delay stochastic differential equation with jumps associate...
Some stability and boundedness criteria for a class of Volterra integro-differential systems
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Jito Vanualailai
2002-01-01
Full Text Available Using Lyapunov and Lyapunov-like functionals, we study the stability and boundedness of the solutions of a system of Volterra integrodifferential equations. Our results, also extending some of the more well-known criteria, give new sufficient conditions for stability of the zero solution of the nonperturbed system, and prove that the same conditions for the perturbed system yield boundedness when the perturbation is $L^2$.
The human body metabolism process mathematical simulation based on Lotka-Volterra model
Oliynyk, Andriy; Oliynyk, Eugene; Pyptiuk, Olexandr; DzierŻak, RóŻa; Szatkowska, Małgorzata; Uvaysova, Svetlana; Kozbekova, Ainur
2017-08-01
The mathematical model of metabolism process in human organism based on Lotka-Volterra model has beeng proposed, considering healing regime, nutrition system, features of insulin and sugar fragmentation process in the organism. The numerical algorithm of the model using IV-order Runge-Kutta method has been realized. After the result of calculations the conclusions have been made, recommendations about using the modeling results have been showed, the vectors of the following researches are defined.
Fault Detection for Shipboard Monitoring – Volterra Kernel and Hammerstein Model Approaches
DEFF Research Database (Denmark)
Lajic, Zoran; Blanke, Mogens; Nielsen, Ulrik Dam
2009-01-01
In this paper nonlinear fault detection for in-service monitoring and decision support systems for ships will be presented. The ship is described as a nonlinear system, and the stochastic wave elevation and the associated ship responses are conveniently modelled in frequency domain. The transform....... The transformation from time domain to frequency domain has been conducted by use of Volterra theory. The paper takes as an example fault detection of a containership on which a decision support system has been installed....
Gelfand-Dikii Hamiltonian operator and co-ad joint representation of the Volterra group
International Nuclear Information System (INIS)
Lebedev, D.R.; Manin, Yu.I.
1978-01-01
It is shown that the Gelfand-Dikii Hamiltonian structure is an analogue of a very special class of finite-dimensional symplectic structures, namely, the Kirillow structures on the orbits of the co-adjoint representation of the Lie groups. The Lie group is represented by the Volterra operators. The main interest lies in the possibility of application of the ideology of ''geometric quantization'' to the Lax equations
Delay-Induced Oscillations in a Competitor-Competitor-Mutualist Lotka-Volterra Model
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Changjin Xu
2017-01-01
Full Text Available This paper deals with a competitor-competitor-mutualist Lotka-Volterra model. A series of sufficient criteria guaranteeing the stability and the occurrence of Hopf bifurcation for the model are obtained. Several concrete formulae determine the properties of bifurcating periodic solutions by applying the normal form theory and the center manifold principle. Computer simulations are given to support the theoretical predictions. At last, biological meaning and a conclusion are presented.
Institute of Scientific and Technical Information of China (English)
LI Shoufu
2005-01-01
A series of stability, contractivity and asymptotic stability results of the solutions to nonlinear stiff Volterra functional differential equations (VFDEs) in Banach spaces is obtained, which provides the unified theoretical foundation for the stability analysis of solutions to nonlinear stiff problems in ordinary differential equations(ODEs), delay differential equations(DDEs), integro-differential equations(IDEs) and VFDEs of other type which appear in practice.
The influence of noise on nonlinear time series detection based on Volterra-Wiener-Korenberg model
Energy Technology Data Exchange (ETDEWEB)
Lei Min [State Key Laboratory of Vibration, Shock and Noise, Shanghai Jiao Tong University, Shanghai 200030 (China)], E-mail: leimin@sjtu.edu.cn; Meng Guang [State Key Laboratory of Vibration, Shock and Noise, Shanghai Jiao Tong University, Shanghai 200030 (China)
2008-04-15
This paper studies the influence of noises on Volterra-Wiener-Korenberg (VWK) nonlinear test model. Our numerical results reveal that different types of noises lead to different behavior of VWK model detection. For dynamic noise, it is difficult to distinguish chaos from nonchaotic but nonlinear determinism. For time series, measure noise has no impact on chaos determinism detection. This paper also discusses various behavior of VWK model detection with surrogate data for different noises.
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Salih Yalcinbas
2016-01-01
Full Text Available In this paper, a new collocation method based on the Fibonacci polynomials is introduced to solve the high-order linear Volterra integro-differential equations under the conditions. Numerical examples are included to demonstrate the applicability and validity of the proposed method and comparisons are made with the existing results. In addition, an error estimation based on the residual functions is presented for this method. The approximate solutions are improved by using this error estimation.
Turing pattern dynamics and adaptive discretization for a superdiffusive Lotka-Volterra system
Bendahmane , Mostafa; Ruiz-Baier , Ricardo; Tian , Canrong
2016-01-01
International audience; We focus our attention on the effects of introducing the fractional-in-space operator into a Lotka-Volterra competitive model describing population superdiffusion. First, we address the weak solvability of the coupled problem employing the Faedo-Galerkin method and compactness arguments. In addition, we are interested in how cross superdiffusion influences the formation of spatial patterns: a linear stability analysis has been carried out, showing that cross superdiffu...
Global stability and quadratic Hamiltonian structure in Lotka-Volterra and quasi-polynomial systems
Energy Technology Data Exchange (ETDEWEB)
Szederkenyi, Gabor; Hangos, Katalin M
2004-04-26
We show that the global stability of quasi-polynomial (QP) and Lotka-Volterra (LV) systems with the well-known logarithmic Lyapunov function is equivalent to the existence of a local generalized dissipative Hamiltonian description of the LV system with a diagonal quadratic form as a Hamiltonian function. The Hamiltonian function can be calculated and the quadratic dissipativity neighborhood of the origin can be estimated by solving linear matrix inequalities.
Existence of Generalized Homoclinic Solutions of Lotka-Volterra System under a Small Perturbation
Mi, Yuzhen
2016-01-01
This paper investigates Lotka-Volterra system under a small perturbation vxx=-μ(1-a2u-v)v+ϵf(ϵ,v,vx,u,ux), uxx=-(1-u-a1v)u+ϵg(ϵ,v,vx,u,ux). By the Fourier series expansion technique method, the fixed point theorem, the perturbation theorem, and the reversibility, we prove that near μ=0 the system has a generalized homoclinic solution exponentially approaching a periodic solution.
Existence of Generalized Homoclinic Solutions of Lotka-Volterra System under a Small Perturbation
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Yuzhen Mi
2016-01-01
Full Text Available This paper investigates Lotka-Volterra system under a small perturbation vxx=-μ(1-a2u-vv+ϵf(ϵ,v,vx,u,ux, uxx=-(1-u-a1vu+ϵg(ϵ,v,vx,u,ux. By the Fourier series expansion technique method, the fixed point theorem, the perturbation theorem, and the reversibility, we prove that near μ=0 the system has a generalized homoclinic solution exponentially approaching a periodic solution.
Global asymptotic behavior in a Lotka–Volterra competition system with spatio-temporal delays
International Nuclear Information System (INIS)
Zhang, Jia-Fang; Chen, Heshan
2014-01-01
This paper is concerned with a Lotka–Volterra competition system with spatio-temporal delays. By using the linearization method, we show the local asymptotic behavior of the nonnegative steady-state solutions. Especially, the global asymptotic stability of the positive steady-state solution is investigated by the method of upper and lower solutions. The result of global asymptotic stability implies that the system has no nonconstant positive steady-state solution
The persistence in a Lotka-Volterra competition systems with impulsive
International Nuclear Information System (INIS)
Zhen Jin; Han Maoan; Li Guihua
2005-01-01
In this paper, a nonautonomous two-dimensional competitive Lotka-Volterra system with impulsive is considered. we study the persistence and extinction, giving two inequalities involving averages of the growth rates and impulsive value, which guarantees persistence of the system. An extension of the principle of competition exclusion is obtained in this paper. Moreover, several examples are also worked out, they show that the impulsive can change the persistence of the system
Global stability and quadratic Hamiltonian structure in Lotka-Volterra and quasi-polynomial systems
Szederkényi, Gábor; Hangos, Katalin M.
2004-04-01
We show that the global stability of quasi-polynomial (QP) and Lotka-Volterra (LV) systems with the well-known logarithmic Lyapunov function is equivalent to the existence of a local generalized dissipative Hamiltonian description of the LV system with a diagonal quadratic form as a Hamiltonian function. The Hamiltonian function can be calculated and the quadratic dissipativity neighborhood of the origin can be estimated by solving linear matrix inequalities.
Global stability and quadratic Hamiltonian structure in Lotka-Volterra and quasi-polynomial systems
International Nuclear Information System (INIS)
Szederkenyi, Gabor; Hangos, Katalin M.
2004-01-01
We show that the global stability of quasi-polynomial (QP) and Lotka-Volterra (LV) systems with the well-known logarithmic Lyapunov function is equivalent to the existence of a local generalized dissipative Hamiltonian description of the LV system with a diagonal quadratic form as a Hamiltonian function. The Hamiltonian function can be calculated and the quadratic dissipativity neighborhood of the origin can be estimated by solving linear matrix inequalities
Cross-diffusional effect in a telegraph reaction diffusion Lotka-Volterra two competitive system
International Nuclear Information System (INIS)
Abdusalam, H.A; Fahmy, E.S.
2003-01-01
It is known now that, telegraph equation is more suitable than ordinary diffusion equation in modelling reaction diffusion in several branches of sciences. Telegraph reaction diffusion Lotka-Volterra two competitive system is considered. We observed that this system can give rise to diffusive instability only in the presence of cross-diffusion. Local and global stability analysis in the cross-diffusional effect are studied by considering suitable Lyapunov functional
Entropy, free energy and phase transitions in the lattice Lotka-Volterra model
International Nuclear Information System (INIS)
Chichigina, O. A.; Tsekouras, G. A.; Provata, A.
2006-01-01
A thermodynamic approach is developed for reactive dynamic models restricted to substrates of arbitrary dimensions, including fractal substrates. The thermodynamic formalism is successfully applied to the lattice Lotka-Volterra (LLV) model of autocatalytic reactions on various lattice substrates. Different regimes of reactions described as phases, and phase transitions, are obtained using this approach. The predictions of thermodynamic theory confirm extensive numerical kinetic Monte Carlo simulations on square and fractal lattices. Extensions of the formalism to multispecies LLV models are also presented
Yin, Fancheng; Yu, Xiaoyan
2015-01-01
This paper is concerned with the existence of stationary distribution and extinction for multispecies stochastic Lotka-Volterra predator-prey system. The contributions of this paper are as follows. (a) By using Lyapunov methods, the sufficient conditions on existence of stationary distribution and extinction are established. (b) By using the space decomposition technique and the continuity of probability, weaker conditions on extinction of the system are obtained. Finally, a numer...
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Behzad Ghanbari
2014-01-01
Full Text Available We aim to study the convergence of the homotopy analysis method (HAM in short for solving special nonlinear Volterra-Fredholm integrodifferential equations. The sufficient condition for the convergence of the method is briefly addressed. Some illustrative examples are also presented to demonstrate the validity and applicability of the technique. Comparison of the obtained results HAM with exact solution shows that the method is reliable and capable of providing analytic treatment for solving such equations.
A novel nonlinear adaptive filter using a pipelined second-order Volterra recurrent neural network.
Zhao, Haiquan; Zhang, Jiashu
2009-12-01
To enhance the performance and overcome the heavy computational complexity of recurrent neural networks (RNN), a novel nonlinear adaptive filter based on a pipelined second-order Volterra recurrent neural network (PSOVRNN) is proposed in this paper. A modified real-time recurrent learning (RTRL) algorithm of the proposed filter is derived in much more detail. The PSOVRNN comprises of a number of simple small-scale second-order Volterra recurrent neural network (SOVRNN) modules. In contrast to the standard RNN, these modules of a PSOVRNN can be performed simultaneously in a pipelined parallelism fashion, which can lead to a significant improvement in its total computational efficiency. Moreover, since each module of the PSOVRNN is a SOVRNN in which nonlinearity is introduced by the recursive second-order Volterra (RSOV) expansion, its performance can be further improved. Computer simulations have demonstrated that the PSOVRNN performs better than the pipelined recurrent neural network (PRNN) and RNN for nonlinear colored signals prediction and nonlinear channel equalization. However, the superiority of the PSOVRNN over the PRNN is at the cost of increasing computational complexity due to the introduced nonlinear expansion of each module.
Cheng, C. M.; Peng, Z. K.; Zhang, W. M.; Meng, G.
2017-03-01
Nonlinear problems have drawn great interest and extensive attention from engineers, physicists and mathematicians and many other scientists because most real systems are inherently nonlinear in nature. To model and analyze nonlinear systems, many mathematical theories and methods have been developed, including Volterra series. In this paper, the basic definition of the Volterra series is recapitulated, together with some frequency domain concepts which are derived from the Volterra series, including the general frequency response function (GFRF), the nonlinear output frequency response function (NOFRF), output frequency response function (OFRF) and associated frequency response function (AFRF). The relationship between the Volterra series and other nonlinear system models and nonlinear problem solving methods are discussed, including the Taylor series, Wiener series, NARMAX model, Hammerstein model, Wiener model, Wiener-Hammerstein model, harmonic balance method, perturbation method and Adomian decomposition. The challenging problems and their state of arts in the series convergence study and the kernel identification study are comprehensively introduced. In addition, a detailed review is then given on the applications of Volterra series in mechanical engineering, aeroelasticity problem, control engineering, electronic and electrical engineering.
Explicit integration of some integrable systems of classical mechanics
Basak Gancheva, Inna
2011-01-01
The main objective of the thesis is the analytical and geometrical study of several integrable finite-dimentional dynamical systems of classical mechanics, which are closely related, namely: - the classical generalization of the Euler top: the Zhukovski-Volterra (ZV) system describing the free motion of a gyrostat, i.e., a rigid body carrying a symmetric rotator whose axis is fixed in the body; - the Steklov-Lyapunov integrable case of the Kirchhoff equations describing the motio...
A Baecklund transformation between two integrable discrete hungry systems
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Fukuda, Akiko, E-mail: j1409704@ed.kagu.tus.ac.j [Department of Mathematical Information Science, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Yamamoto, Yusaku [Graduate School of System Informatics, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501 (Japan); Iwasaki, Masashi [Department of Informatics and Environmental Science, Kyoto Prefectural University, 1-5, Nakaragi-cho, Shimogamo, Sakyo-ku, Kyoto 606-8522 (Japan); Ishiwata, Emiko [Department of Mathematical Information Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Nakamura, Yoshimasa [Graduate School of Informatics, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)
2011-01-17
The discrete hungry Toda (dhToda) equation and the discrete hungry Lotka-Volterra (dhLV) system are known as integrable discrete hungry systems. In this Letter, through finding the LR transformations associated with the dhToda equation and the dhLV system, we present a Baecklund transformation between these integrable systems.
A Baecklund transformation between two integrable discrete hungry systems
International Nuclear Information System (INIS)
Fukuda, Akiko; Yamamoto, Yusaku; Iwasaki, Masashi; Ishiwata, Emiko; Nakamura, Yoshimasa
2011-01-01
The discrete hungry Toda (dhToda) equation and the discrete hungry Lotka-Volterra (dhLV) system are known as integrable discrete hungry systems. In this Letter, through finding the LR transformations associated with the dhToda equation and the dhLV system, we present a Baecklund transformation between these integrable systems.
Solutions of First-Order Volterra Type Linear Integrodifferential Equations by Collocation Method
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Olumuyiwa A. Agbolade
2017-01-01
Full Text Available The numerical solutions of linear integrodifferential equations of Volterra type have been considered. Power series is used as the basis polynomial to approximate the solution of the problem. Furthermore, standard and Chebyshev-Gauss-Lobatto collocation points were, respectively, chosen to collocate the approximate solution. Numerical experiments are performed on some sample problems already solved by homotopy analysis method and finite difference methods. Comparison of the absolute error is obtained from the present method and those from aforementioned methods. It is also observed that the absolute errors obtained are very low establishing convergence and computational efficiency.
A differential-difference hierarchy associated with relativistic Toda and Volterra hierarchies
International Nuclear Information System (INIS)
Fan Engui; Dai Huihui
2008-01-01
By embedding a free function into a compatible zero curvature equation, we enlarge the original differential-difference hierarchy into a new hierarchy with the free function which still admits zero curvature representation. The new hierarchy not only includes the original hierarchy, but also the well-known relativistic Toda hierarchy and the Volterra hierarchy as special reductions by properly choosing the free function. Infinitely many conservation laws and Darboux transformation for a representative differential-difference system are constructed based on its Lax representation. The exact solutions follow by applying the Darboux transformation
International Nuclear Information System (INIS)
Dehghan, Mehdi; Shakourifar, Mohammad; Hamidi, Asgar
2009-01-01
The purpose of this study is to implement Adomian-Pade (Modified Adomian-Pade) technique, which is a combination of Adomian decomposition method (Modified Adomian decomposition method) and Pade approximation, for solving linear and nonlinear systems of Volterra functional equations. The results obtained by using Adomian-Pade (Modified Adomian-Pade) technique, are compared to those obtained by using Adomian decomposition method (Modified Adomian decomposition method) alone. The numerical results, demonstrate that ADM-PADE (MADM-PADE) technique, gives the approximate solution with faster convergence rate and higher accuracy than using the standard ADM (MADM).
A modified Lotka-Volterra model for the evolution of coordinate symbiosis in energy enterprise
Zhou, Li; Wang, Teng; Lyu, Xiaohuan; Yu, Jing
2018-02-01
Recent developments in energy markets make the operating industries more dynamic and complex, and energy enterprises cooperate more closely in the industrial chain and symbiosis. In order to further discuss the evolution of coordinate symbiosis in energy enterprises, a modified Lotka-Volterra equation is introduced to develop a symbiosis analysis model of energy groups. According to the equilibrium and stability analysis, a conclusion is obtained that if the upstream energy group and the downstream energy group are in symbiotic state, the growth of their utility will be greater than their independent value. Energy enterprises can get mutual benefits and positive promotions in industrial chain by their cooperation.
Mapping of the stochastic Lotka-Volterra model to models of population genetics and game theory
Constable, George W. A.; McKane, Alan J.
2017-08-01
The relationship between the M -species stochastic Lotka-Volterra competition (SLVC) model and the M -allele Moran model of population genetics is explored via timescale separation arguments. When selection for species is weak and the population size is large but finite, precise conditions are determined for the stochastic dynamics of the SLVC model to be mappable to the neutral Moran model, the Moran model with frequency-independent selection, and the Moran model with frequency-dependent selection (equivalently a game-theoretic formulation of the Moran model). We demonstrate how these mappings can be used to calculate extinction probabilities and the times until a species' extinction in the SLVC model.
Chakrabarti, Anindya S.
2016-01-01
We present a model of technological evolution due to interaction between multiple countries and the resultant effects on the corresponding macro variables. The world consists of a set of economies where some countries are leaders and some are followers in the technology ladder. All of them potentially gain from technological breakthroughs. Applying Lotka-Volterra (LV) equations to model evolution of the technology frontier, we show that the way technology diffuses creates repercussions in the partner economies. This process captures the spill-over effects on major macro variables seen in the current highly globalized world due to trickle-down effects of technology.
String networks in Z{sub N} Lotka–Volterra competition models
Energy Technology Data Exchange (ETDEWEB)
Avelino, P.P., E-mail: Pedro.Avelino@astro.up.pt [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Bazeia, D. [Instituto de Física, Universidade de São Paulo, 05314-970 São Paulo, SP (Brazil); Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Menezes, J. [Centro de Física do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, Caixa Postal 1524, 59072-970 Natal, RN (Brazil); Oliveira, B.F. de [Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900 Maringá, PR (Brazil)
2014-01-17
In this Letter we give specific examples of Z{sub N} Lotka–Volterra competition models leading to the formation of string networks. We show that, in order to promote coexistence, the species may arrange themselves around regions with a high number density of empty sites generated by predator–prey interactions between competing species. These configurations extend into the third dimension giving rise to string networks. We investigate the corresponding dynamics using both stochastic and mean field theory simulations, showing that the coarsening of these string networks follows a scaling law which is analogous to that found in other physical systems in condensed matter and cosmology.
Faria, Teresa; Oliveira, José J.
This paper addresses the local and global stability of n-dimensional Lotka-Volterra systems with distributed delays and instantaneous negative feedbacks. Necessary and sufficient conditions for local stability independent of the choice of the delay functions are given, by imposing a weak nondelayed diagonal dominance which cancels the delayed competition effect. The global asymptotic stability of positive equilibria is established under conditions slightly stronger than the ones required for the linear stability. For the case of monotone interactions, however, sharper conditions are presented. This paper generalizes known results for discrete delays to systems with distributed delays. Several applications illustrate the results.
Stabilization of Large Generalized Lotka-Volterra Foodwebs By Evolutionary Feedback
Ackland, G. J.; Gallagher, I. D.
2004-10-01
Conventional ecological models show that complexity destabilizes foodwebs, suggesting that foodwebs should have neither large numbers of species nor a large number of interactions. However, in nature the opposite appears to be the case. Here we show that if the interactions between species are allowed to evolve within a generalized Lotka-Volterra model such stabilizing feedbacks and weak interactions emerge automatically. Moreover, we show that trophic levels also emerge spontaneously from the evolutionary approach, and the efficiency of the unperturbed ecosystem increases with time. The key to stability in large foodwebs appears to arise not from complexity perse but from evolution at the level of the ecosystem which favors stabilizing (negative) feedbacks.
Nonmonotonic Behavior of Supermultiplet Pattern Formation in a Noisy Lotka-Volterra System
International Nuclear Information System (INIS)
Fiasconaro, A.; Valenti, D.; Spagnolo, B.
2004-01-01
The noise-induced pattern formation in a population dynamical model of three interacting species in the coexistence regime is investigated. A coupled map lattice of Lotka-Volterra equations in the presence of multiplicative noise is used to analyze the spatiotemporal evolution. The spatial correlation of the species concentration as a function of time and of the noise intensity is investigated. A nonmonotonic behavior of the area of the patterns as a function of both noise intensity and evolution time is found. (author)
Stable power laws in variable economies; Lotka-Volterra implies Pareto-Zipf
Solomon, S.; Richmond, P.
2002-05-01
In recent years we have found that logistic systems of the Generalized Lotka-Volterra type (GLV) describing statistical systems of auto-catalytic elements posses power law distributions of the Pareto-Zipf type. In particular, when applied to economic systems, GLV leads to power laws in the relative individual wealth distribution and in market returns. These power laws and their exponent α are invariant to arbitrary variations in the total wealth of the system and to other endogenously and exogenously induced variations.
Entire solutions of a diffusive and competitive Lotka–Volterra type system with nonlocal delays
International Nuclear Information System (INIS)
Wang, Mingxin; Lv, Guangying
2010-01-01
This paper is concerned with the entire solution of a diffusive and competitive Lotka–Volterra type system with nonlocal delays. The existence of the entire solution is proved by transforming the system with nonlocal delays to a four-dimensional system without delay and using the comparing argument and the sub-super-solution method. Here an entire solution means a classical solution defined for all space and time variables, which behaves as two wave fronts coming from both sides of the x-axis
The inverse problem of determining several coefficients in a nonlinear Lotka–Volterra system
International Nuclear Information System (INIS)
Roques, Lionel; Cristofol, Michel
2012-01-01
In this paper, we prove a uniqueness result in the inverse problem of determining several non-constant coefficients of a system of two parabolic equations, which corresponds to a Lotka–Volterra competition model. Our result gives a sufficient condition for the uniqueness of the determination of four coefficients of the system. This sufficient condition only involves pointwise measurements of the solution (u, v) of the system and of the spatial derivative ∂u/∂x or ∂v/∂x of one component at a single point x 0 , during a time interval (0, ε). Our results are illustrated by numerical computations. (paper)
Dynamics of a Lotka-Volterra type model with applications to marine phage population dynamics
International Nuclear Information System (INIS)
Gavin, C; Pokrovskii, A; Prentice, M; Sobolev, V
2006-01-01
The famous Lotka-Volterra equations play a fundamental role in the mathematical modeling of various ecological and chemical systems. A new modification of these equations has been recently suggested to model the structure of marine phage populations, which are the most abundant biological entities in the biosphere. The purpose of the paper is: (i) to make some methodical remarks concerning this modification; (ii) to discuss new types of canards which arise naturally in this context; (iii) to present results of some numerical experiments
Identificación de sistemas no lineales usando series Volterra – Laguerre
Medina Ramos, Carlos Celestino; Medina Ramos, Carlos Celestino
2011-01-01
Este trabajo de Tesis está enfocado en la identificación de sistemas no lineales de modelo dinámico no conocido, adicionalmente y en base a los resultados obtenidos, se propone la aplicación del sistema de Control Predictivo no Lineal Basado en Modelos, NMPC, usando el algoritmo de la Matriz Dinámica de Control no Lineal, NDMC. El primer objetivo de este trabajo consiste en implementar una metodología para la identificación de sistemas no lineales usando series de Volterra truncadas; proye...
Nonlinear degradation of a visible-light communication link: A Volterra-series approach
Kamalakis, Thomas; Dede, Georgia
2018-06-01
Visible light communications can be used to provide illumination and data communication at the same time. In this paper, a reverse-engineering approach is presented for assessing the impact of nonlinear signal distortion in visible light communication links. The approach is based on the Volterra series expansion and has the advantage of accurately accounting for memory effects in contrast to the static nonlinear models that are popular in the literature. Volterra kernels describe the end-to-end system response and can be inferred from measurements. Consequently, this approach does not rely on any particular physical models and assumptions regarding the individual link components. We provide the necessary framework for estimating the nonlinear distortion on the symbol estimates of a discrete multitone modulated link. Various design aspects such as waveform clipping and predistortion are also incorporated in the analysis. Using this framework, the nonlinear signal-to-interference is calculated for the system at hand. It is shown that at high signal amplitudes, the nonlinear signal-to-interference can be less than 25 dB.
Filtered-X Affine Projection Algorithms for Active Noise Control Using Volterra Filters
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Sicuranza Giovanni L
2004-01-01
Full Text Available We consider the use of adaptive Volterra filters, implemented in the form of multichannel filter banks, as nonlinear active noise controllers. In particular, we discuss the derivation of filtered-X affine projection algorithms for homogeneous quadratic filters. According to the multichannel approach, it is then easy to pass from these algorithms to those of a generic Volterra filter. It is shown in the paper that the AP technique offers better convergence and tracking capabilities than the classical LMS and NLMS algorithms usually applied in nonlinear active noise controllers, with a limited complexity increase. This paper extends in two ways the content of a previous contribution published in Proc. IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing (NSIP '03, Grado, Italy, June 2003. First of all, a general adaptation algorithm valid for any order of affine projections is presented. Secondly, a more complete set of experiments is reported. In particular, the effects of using multichannel filter banks with a reduced number of channels are investigated and relevant results are shown.
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Xuecheng Zheng
2016-07-01
Conclusion: The relationship among microorganisms during leaching could be described appropriately by Lotka–Volterra model between the initial and peak values. The relationship of A. ferrooxidans and R. phaseoli could be considered as mutualism, whereas, the relationship of A. ferrooxidans and R. phaseoli could be considered as commensalism.
Energy Technology Data Exchange (ETDEWEB)
Jin Zhen E-mail: jinzhn@263.net; Ma Zhien; Maoan Han
2004-10-01
In this paper, we study the existence of positive periodic solutions of periodic n-species Lotka-Volterra competition systems with impulses. By using the method coincidence degree theorem, a set of easily verifiable sufficient conditions are obtained for the existence of at least one strictly positive periodic solutions. Some known results are improved and generalized.
International Nuclear Information System (INIS)
Jin Zhen; Ma Zhien; Maoan Han
2004-01-01
In this paper, we study the existence of positive periodic solutions of periodic n-species Lotka-Volterra competition systems with impulses. By using the method coincidence degree theorem, a set of easily verifiable sufficient conditions are obtained for the existence of at least one strictly positive periodic solutions. Some known results are improved and generalized
Exponential Convergence for Numerical Solution of Integral Equations Using Radial Basis Functions
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Zakieh Avazzadeh
2014-01-01
Full Text Available We solve some different type of Urysohn integral equations by using the radial basis functions. These types include the linear and nonlinear Fredholm, Volterra, and mixed Volterra-Fredholm integral equations. Our main aim is to investigate the rate of convergence to solve these equations using the radial basis functions which have normic structure that utilize approximation in higher dimensions. Of course, the use of this method often leads to ill-posed systems. Thus we propose an algorithm to improve the results. Numerical results show that this method leads to the exponential convergence for solving integral equations as it was already confirmed for partial and ordinary differential equations.
Liu, Na; Ju, Cheng
2018-02-01
Nyquist-SCM signal after fiber transmission, direct detection (DD), and analog down-conversion suffers from linear ISI, nonlinear ISI, and I/Q imbalance, simultaneously. Theoretical analysis based on widely linear (WL) and Volterra series is given to explain the relationship and interaction of these three interferences. A blind equalization algorithm, cascaded WL and Volterra equalizer, is designed to mitigate these three interferences. Furthermore, the feasibility of the proposed cascaded algorithm is experimentally demonstrated based on a 40-Gbps data rate 16-quadrature amplitude modulation (QAM) virtual single sideband (VSSB) Nyquist-SCM DD system over 100-km standard single mode fiber (SSMF) transmission. In addition, the performances of conventional strictly linear equalizer, WL equalizer, Volterra equalizer, and cascaded WL and Volterra equalizer are experimentally evaluated, respectively.
A Multiple Iterated Integral Inequality and Applications
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Zongyi Hou
2014-01-01
Full Text Available We establish new multiple iterated Volterra-Fredholm type integral inequalities, where the composite function w(u(s of the unknown function u with nonlinear function w in integral functions in [Ma, QH, Pečarić, J: Estimates on solutions of some new nonlinear retarded Volterra-Fredholm type integral inequalities. Nonlinear Anal. 69 (2008 393–407] is changed into the composite functions w1(u(s,w2(u(s,…, wn (u(s of the unknown function u with different nonlinear functions w1,w2,…,wn, respectively. By adopting novel analysis techniques, the upper bounds of the embedded unknown functions are estimated explicitly. The derived results can be applied in the study of solutions of ordinary differential equations and integral equations.
Asymptotic Behaviour and Extinction of Delay Lotka-Volterra Model with Jump-Diffusion
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Dan Li
2014-01-01
Full Text Available This paper studies the effect of jump-diffusion random environmental perturbations on the asymptotic behaviour and extinction of Lotka-Volterra population dynamics with delays. The contributions of this paper lie in the following: (a to consider delay stochastic differential equation with jumps, we introduce a proper initial data space, in which the initial data may be discontinuous function with downward jumps; (b we show that the delay stochastic differential equation with jumps associated with our model has a unique global positive solution and give sufficient conditions that ensure stochastically ultimate boundedness, moment average boundedness in time, and asymptotic polynomial growth of our model; (c the sufficient conditions for the extinction of the system are obtained, which generalized the former results and showed that the sufficiently large random jump magnitudes and intensity (average rate of jump events arrival may lead to extinction of the population.
Bifurcation analysis in the diffusive Lotka-Volterra system: An application to market economy
International Nuclear Information System (INIS)
Wijeratne, A.W.; Yi Fengqi; Wei Junjie
2009-01-01
A diffusive Lotka-Volterra system is formulated in this paper that represents the dynamics of market share at duopoly. A case in Sri Lankan mobile telecom market was considered that conceptualized the model in interest. Detailed Hopf bifurcation, transcritical and pitchfork bifurcation analysis were performed. The distribution of roots of the characteristic equation suggests that a stable coexistence equilibrium can be achieved by increasing the innovation while minimizing competition by each competitor while regulating existing policies and introducing new ones for product differentiation and value addition. The avenue is open for future research that may use real time information in order to formulate mathematically sound tools for decision making in competitive business environments.
Bifurcation analysis in the diffusive Lotka-Volterra system: An application to market economy
Energy Technology Data Exchange (ETDEWEB)
Wijeratne, A.W. [Department of Mathematics, Harbin Institute of Technology, Harbin 150001 (China); Department of Agri-Business Management, Sabaragamuwa University of Sri Lanka, Belihuloya 70140 (Sri Lanka); Yi Fengqi [Department of Mathematics, Harbin Institute of Technology, Harbin 150001 (China); Wei Junjie [Department of Mathematics, Harbin Institute of Technology, Harbin 150001 (China)], E-mail: weijj@hit.edu.cn
2009-04-30
A diffusive Lotka-Volterra system is formulated in this paper that represents the dynamics of market share at duopoly. A case in Sri Lankan mobile telecom market was considered that conceptualized the model in interest. Detailed Hopf bifurcation, transcritical and pitchfork bifurcation analysis were performed. The distribution of roots of the characteristic equation suggests that a stable coexistence equilibrium can be achieved by increasing the innovation while minimizing competition by each competitor while regulating existing policies and introducing new ones for product differentiation and value addition. The avenue is open for future research that may use real time information in order to formulate mathematically sound tools for decision making in competitive business environments.
The diffusive Lotka-Volterra predator-prey system with delay.
Al Noufaey, K S; Marchant, T R; Edwards, M P
2015-12-01
Semi-analytical solutions for the diffusive Lotka-Volterra predator-prey system with delay are considered in one and two-dimensional domains. The Galerkin method is applied, which approximates the spatial structure of both the predator and prey populations. This approach is used to obtain a lower-order, ordinary differential delay equation model for the system of governing delay partial differential equations. Steady-state and transient solutions and the region of parameter space, in which Hopf bifurcations occur, are all found. In some cases simple linear expressions are found as approximations, to describe steady-state solutions and the Hopf parameter regions. An asymptotic analysis for the periodic solution near the Hopf bifurcation point is performed for the one-dimensional domain. An excellent agreement is shown in comparisons between semi-analytical and numerical solutions of the governing equations. Copyright © 2015 Elsevier Inc. All rights reserved.
Volterra series based predistortion for broadband RF power amplifiers with memory effects
Institute of Scientific and Technical Information of China (English)
Jin Zhe; Song Zhihuan; He Jiaming
2008-01-01
RF power amplifiers(PAs)are usually considered as memoryless devices in most existing predistortion techniques.However,in broadband communication systems,such as WCDMA,the PA memory effects are significant,and memoryless predistortion cannot linearize the PAs effectively.After analyzing the PA memory effects,a novel predistortion method based on the simplified Volterra series is proposed to linearize broadband RF PAs with memory effects.The indirect learning architecture is adopted to design the predistortion scheme and the recursive least squares algorithm with forgetting factor is applied to identify the parameters of the predistorter.Simulation results show that the proposed predistortion method can compensate the nonlinear distortion and memory effects of broadband RF PAs effectively.
Winnerless competition principle and prediction of the transient dynamics in a Lotka-Volterra model
Afraimovich, Valentin; Tristan, Irma; Huerta, Ramon; Rabinovich, Mikhail I.
2008-12-01
Predicting the evolution of multispecies ecological systems is an intriguing problem. A sufficiently complex model with the necessary predicting power requires solutions that are structurally stable. Small variations of the system parameters should not qualitatively perturb its solutions. When one is interested in just asymptotic results of evolution (as time goes to infinity), then the problem has a straightforward mathematical image involving simple attractors (fixed points or limit cycles) of a dynamical system. However, for an accurate prediction of evolution, the analysis of transient solutions is critical. In this paper, in the framework of the traditional Lotka-Volterra model (generalized in some sense), we show that the transient solution representing multispecies sequential competition can be reproducible and predictable with high probability.
Dynamic behaviors of the periodic Lotka-Volterra competing system with impulsive perturbations
International Nuclear Information System (INIS)
Liu Bing; Teng Zhidong; Liu Wanbo
2007-01-01
In this paper, we investigate a classical periodic Lotka-Volterra competing system with impulsive perturbations. The conditions for the linear stability of trivial periodic solution and semi-trivial periodic solutions are given by applying Floquet theory of linear periodic impulsive equation, and we also give the conditions for the global stability of these solutions as a consequence of some abstract monotone iterative schemes introduced in this paper, which will be also used to get some sufficient conditions for persistence. By using the method of coincidence degree, the conditions for the existence of at least one strictly positive (componentwise) periodic solution are derived. The theoretical results are confirmed by a specific example and numerical simulations. It shows that the dynamic behaviors of the system we consider are quite different from the corresponding system without pulses
An introduction to mathematical population dynamics along the trail of Volterra and Lotka
Iannelli, Mimmo
2014-01-01
This book is an introduction to mathematical biology for students with no experience in biology, but who have some mathematical background. The work is focused on population dynamics and ecology, following a tradition that goes back to Lotka and Volterra, and includes a part devoted to the spread of infectious diseases, a field where mathematical modeling is extremely popular. These themes are used as the area where to understand different types of mathematical modeling and the possible meaning of qualitative agreement of modeling with data. The book also includes a collections of problems designed to approach more advanced questions. This material has been used in the courses at the University of Trento, directed at students in their fourth year of studies in Mathematics. It can also be used as a reference as it provides up-to-date developments in several areas.
INTEGRATION OF AN ECONOMIC WITH AN ECOLOGICAL MODEL
We summarize our work on integration of an economy under imperfect competition with a simple Lotka-Volterra type ecological model. Firms and households operate within a single period planning horizon, thus there is no savings or investment. Wages are set by a dominant employer. P...
Bountis, Tassos; Vanhaecke, Pol
2017-12-01
The comment made after the proof of Proposition 3.3, in our paper [T. Bountis, P. Vanhaecke, Lotka-Volterra systems satisfying a strong Pailevé property, Phys. Lett. A 380 (47) (2016) 3977-3982], saying that the proposition can be generalized when linear terms are added to the Lotka-Volterra systems considered in the paper, is wrong. In general such deformed systems are not even Hamiltonian.
Del Soldato, Matteo; Bianchini, Silvia; Nolesini, Teresa; Frodella, William; Casagli, Nicola
2017-04-01
Multisystem remote sensing techniques were exploited to provide a comprehensive overview of Volterra (Italy) site stability with regards to its landscape, urban fabric and cultural heritage. Interferometric Synthetic Aperture Radar (InSAR) techniques allow precise measurements of Earth surface displacement, as well as the detection of building deformations on large urban areas. In the field of cultural heritage conservation Infrared thermography (IRT) provides surface temperature mapping and therefore detects various potential criticalities, such as moisture, seepage areas, cracks and structural anomalies. Between winter 2014 and spring 2015 the historical center and south-western sectors of Volterra (Tuscany region, central Italy) were affected by instability phenomena. The spatial distribution, typology and effect on the urban fabrics of the landslide phenomena were investigated by analyzing the geological and geomorphological settings, traditional geotechnical monitoring and advanced remote sensing data such as Persistent Scatterers Interferometry (PSI). The ground deformation rates and the maximum settlement values derived from SAR acquisitions of historical ENVISAT and recent COSMO-SkyMed sensors, in 2003-2009 and 2010-2015 respectively, were compared with background geological data, constructive features, in situ evidences and detailed field inspections in order to classify landslide-damaged buildings. In this way, the detected movements and their potential correspondences with recognized damages were investigated in order to perform an assessment of the built-up areas deformations and damages on Volterra. The IRT technique was applied in order to survey the surface temperature of the historical Volterra wall-enclosure, and allowed highlighting thermal anomalies on this cultural heritage element of the site. The obtained results permitted to better correlate the landslide effects of the recognized deformations in the urban fabric, in order to provide useful
Non-equilibrium relaxation in a stochastic lattice Lotka-Volterra model
Chen, Sheng; Täuber, Uwe C.
2016-04-01
We employ Monte Carlo simulations to study a stochastic Lotka-Volterra model on a two-dimensional square lattice with periodic boundary conditions. If the (local) prey carrying capacity is finite, there exists an extinction threshold for the predator population that separates a stable active two-species coexistence phase from an inactive state wherein only prey survive. Holding all other rates fixed, we investigate the non-equilibrium relaxation of the predator density in the vicinity of the critical predation rate. As expected, we observe critical slowing-down, i.e., a power law dependence of the relaxation time on the predation rate, and algebraic decay of the predator density at the extinction critical point. The numerically determined critical exponents are in accord with the established values of the directed percolation universality class. Following a sudden predation rate change to its critical value, one finds critical aging for the predator density autocorrelation function that is also governed by universal scaling exponents. This aging scaling signature of the active-to-absorbing state phase transition emerges at significantly earlier times than the stationary critical power laws, and could thus serve as an advanced indicator of the (predator) population’s proximity to its extinction threshold.
Hu, Eric Y; Bouteiller, Jean-Marie C; Song, Dong; Baudry, Michel; Berger, Theodore W
2015-01-01
Chemical synapses are comprised of a wide collection of intricate signaling pathways involving complex dynamics. These mechanisms are often reduced to simple spikes or exponential representations in order to enable computer simulations at higher spatial levels of complexity. However, these representations cannot capture important nonlinear dynamics found in synaptic transmission. Here, we propose an input-output (IO) synapse model capable of generating complex nonlinear dynamics while maintaining low computational complexity. This IO synapse model is an extension of a detailed mechanistic glutamatergic synapse model capable of capturing the input-output relationships of the mechanistic model using the Volterra functional power series. We demonstrate that the IO synapse model is able to successfully track the nonlinear dynamics of the synapse up to the third order with high accuracy. We also evaluate the accuracy of the IO synapse model at different input frequencies and compared its performance with that of kinetic models in compartmental neuron models. Our results demonstrate that the IO synapse model is capable of efficiently replicating complex nonlinear dynamics that were represented in the original mechanistic model and provide a method to replicate complex and diverse synaptic transmission within neuron network simulations.
Survival behavior in the cyclic Lotka-Volterra model with a randomly switching reaction rate
West, Robert; Mobilia, Mauro; Rucklidge, Alastair M.
2018-02-01
We study the influence of a randomly switching reproduction-predation rate on the survival behavior of the nonspatial cyclic Lotka-Volterra model, also known as the zero-sum rock-paper-scissors game, used to metaphorically describe the cyclic competition between three species. In large and finite populations, demographic fluctuations (internal noise) drive two species to extinction in a finite time, while the species with the smallest reproduction-predation rate is the most likely to be the surviving one (law of the weakest). Here we model environmental (external) noise by assuming that the reproduction-predation rate of the strongest species (the fastest to reproduce and predate) in a given static environment randomly switches between two values corresponding to more and less favorable external conditions. We study the joint effect of environmental and demographic noise on the species survival probabilities and on the mean extinction time. In particular, we investigate whether the survival probabilities follow the law of the weakest and analyze their dependence on the external noise intensity and switching rate. Remarkably, when, on average, there is a finite number of switches prior to extinction, the survival probability of the predator of the species whose reaction rate switches typically varies nonmonotonically with the external noise intensity (with optimal survival about a critical noise strength). We also outline the relationship with the case where all reaction rates switch on markedly different time scales.
A slow pushed front in a Lotka–Volterra competition model
International Nuclear Information System (INIS)
Holzer, Matt; Scheel, Arnd
2012-01-01
We study invasion speeds in the Lotka–Volterra competition model when the rate of diffusion of one species is small. Our main result is the construction of the selected front and a rigorous asymptotic approximation of its propagation speed, valid to second order. We use techniques from geometric singular perturbation theory and geometric desingularization. The main challenge arises from the slow passage through a saddle-node bifurcation. From a perspective of linear versus nonlinear speed selection, this front provides an interesting example as the propagation speed is slower than the linear spreading speed. However, our front shares many characteristics with pushed fronts that arise when the influence of nonlinearity leads to faster than linear speeds of propagation. We show that this is a result of the linear spreading speed arising as a simple pole of the resolvent instead of as a branch pole. Using the pointwise Green's function, we show that this pole poses no a priori obstacle to marginal stability of the nonlinear travelling front, thus explaining how nonlinear systems can exhibit slower spreading that their linearization in a robust fashion
Survival behavior in the cyclic Lotka-Volterra model with a randomly switching reaction rate.
West, Robert; Mobilia, Mauro; Rucklidge, Alastair M
2018-02-01
We study the influence of a randomly switching reproduction-predation rate on the survival behavior of the nonspatial cyclic Lotka-Volterra model, also known as the zero-sum rock-paper-scissors game, used to metaphorically describe the cyclic competition between three species. In large and finite populations, demographic fluctuations (internal noise) drive two species to extinction in a finite time, while the species with the smallest reproduction-predation rate is the most likely to be the surviving one (law of the weakest). Here we model environmental (external) noise by assuming that the reproduction-predation rate of the strongest species (the fastest to reproduce and predate) in a given static environment randomly switches between two values corresponding to more and less favorable external conditions. We study the joint effect of environmental and demographic noise on the species survival probabilities and on the mean extinction time. In particular, we investigate whether the survival probabilities follow the law of the weakest and analyze their dependence on the external noise intensity and switching rate. Remarkably, when, on average, there is a finite number of switches prior to extinction, the survival probability of the predator of the species whose reaction rate switches typically varies nonmonotonically with the external noise intensity (with optimal survival about a critical noise strength). We also outline the relationship with the case where all reaction rates switch on markedly different time scales.
The Port Service Ecosystem Research Based on the Lotka-Volterra Model
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Li Wenjuan
2017-11-01
Full Text Available Under the new normal of China’s economy, the competition among the port enterprises is not only the competition of the core competence of the port, the port industry chain or the port supply chain, but also the competition of the port service ecosystem. In this paper, the concept and characteristics of the port service ecosystem is discussed, a hierarchical model of the port service ecosystem is constructed. As an extended logistic model, Lotka-Volterra model is applied to study the competitive co-evolution and mutually beneficial co-evolution of enterprises in the port service ecosystem. This paper simulates the co-evolution of enterprises in the port service ecosystem by using MATLAB programming. The simulation results show that the breadth of the niche of the enterprises is changing with the change of the competition coefficient and the coefficient of mutual benefit in the port service ecosystem. Based on that, some proposals are put forward to ensure the healthy and orderly development of the port service ecosystem.
Global analysis of an impulsive delayed Lotka-Volterra competition system
Xia, Yonghui
2011-03-01
In this paper, a retarded impulsive n-species Lotka-Volterra competition system with feedback controls is studied. Some sufficient conditions are obtained to guarantee the global exponential stability and global asymptotic stability of a unique equilibrium for such a high-dimensional biological system. The problem considered in this paper is in many aspects more general and incorporates as special cases various problems which have been extensively studied in the literature. Moreover, applying the obtained results to some special cases, I derive some new criteria which generalize and greatly improve some well known results. A method is proposed to investigate biological systems subjected to the effect of both impulses and delays. The method is based on Banach fixed point theory and matrix's spectral theory as well as Lyapunov function. Moreover, some novel analytic techniques are employed to study GAS and GES. It is believed that the method can be extended to other high-dimensional biological systems and complex neural networks. Finally, two examples show the feasibility of the results.
Positive periodic solutions of periodic neutral Lotka-Volterra system with distributed delays
International Nuclear Information System (INIS)
Li Yongkun
2008-01-01
By using a fixed point theorem of strict-set-contraction, some criteria are established for the existence of positive periodic solutions of the following periodic neutral Lotka-Volterra system with distributed delays (dx i (t))/(dt) =x i (t)[a i (t)-Σ j=1 n b ij (t)∫ -T ij 0 K ij (θ)x j ( t+θ)dθ-Σ j=1 n c ij (t)∫ -T ij 0 K ij (θ) x j ' (t+θ)dθ],i=1,2,...,n, where a i ,b ij ,c ij element of C(R,R + ) (i, j = 1, 2, ..., n) are ω-periodic functions, T ij ,T ij element of (0,∞) (i, j = 1, 2, ..., n) and K ij ,K ij element of (R,R + ) satisfying ∫ -T ij 0 K ij (θ)dθ=1,∫ -T ij 0 K ij (θ)dθ=1, i, j = 1, 2, ..., n
Theoretical analysis and simulations of the generalized Lotka-Volterra model
Malcai, Ofer; Biham, Ofer; Richmond, Peter; Solomon, Sorin
2002-09-01
The dynamics of generalized Lotka-Volterra systems is studied by theoretical techniques and computer simulations. These systems describe the time evolution of the wealth distribution of individuals in a society, as well as of the market values of firms in the stock market. The individual wealths or market values are given by a set of time dependent variables wi, i=1,...,N. The equations include a stochastic autocatalytic term (representing investments), a drift term (representing social security payments), and a time dependent saturation term (due to the finite size of the economy). The wi's turn out to exhibit a power-law distribution of the form P(w)~w-1-α. It is shown analytically that the exponent α can be expressed as a function of one parameter, which is the ratio between the constant drift component (social security) and the fluctuating component (investments). This result provides a link between the lower and upper cutoffs of this distribution, namely, between the resources available to the poorest and those available to the richest in a given society. The value of α is found to be insensitive to variations in the saturation term, which represent the expansion or contraction of the economy. The results are of much relevance to empirical studies that show that the distribution of the individual wealth in different countries during different periods in the 20th century has followed a power-law distribution with 1<α<2.
A new approach to stochastic transport via the functional Volterra expansion
International Nuclear Information System (INIS)
Ziya Akcasu, A.; Corngold, N.
2005-01-01
In this paper we present a new algorithm (FDA) for the calculation of the mean and the variance of the flux in stochastic transport when the transport equation contains a spatially random parameter θ(r), such as the density of the medium. The approach is based on the renormalized functional Volterra expansion of the flux around its mean. The attractive feature of the approach is that it explicitly displays the functional dependence of the flux on the products of θ(r i ), and hence enables one to take ensemble averages directly to calculate the moments of the flux in terms of the correlation functions of the underlying random process. The renormalized deterministic transport equation for the mean flux has been obtained to the second order in θ(r), and a functional relationship between the variance and the mean flux has been derived to calculate the variance to this order. The feasibility and accuracy of FDA has been demonstrated in the case of stochastic diffusion, using the diffusion equation with a spatially random diffusion coefficient. The connection of FDA with the well-established approximation schemes in the field of stochastic linear differential equations, such as the Bourret approximation, developed by Van Kampen using cumulant expansion, and by Terwiel using projection operator formalism, which has recently been extended to stochastic transport by Corngold. We hope that FDA's potential will be explored numerically in more realistic applications of the stochastic transport. (authors)
General two-species interacting Lotka-Volterra system: Population dynamics and wave propagation
Zhu, Haoqi; Wang, Mao-Xiang; Lai, Pik-Yin
2018-05-01
The population dynamics of two interacting species modeled by the Lotka-Volterra (LV) model with general parameters that can promote or suppress the other species is studied. It is found that the properties of the two species' isoclines determine the interaction of species, leading to six regimes in the phase diagram of interspecies interaction; i.e., there are six different interspecific relationships described by the LV model. Four regimes allow for nontrivial species coexistence, among which it is found that three of them are stable, namely, weak competition, mutualism, and predator-prey scenarios can lead to win-win coexistence situations. The Lyapunov function for general nontrivial two-species coexistence is also constructed. Furthermore, in the presence of spatial diffusion of the species, the dynamics can lead to steady wavefront propagation and can alter the population map. Propagating wavefront solutions in one dimension are investigated analytically and by numerical solutions. The steady wavefront speeds are obtained analytically via nonlinear dynamics analysis and verified by numerical solutions. In addition to the inter- and intraspecific interaction parameters, the intrinsic speed parameters of each species play a decisive role in species populations and wave properties. In some regimes, both species can copropagate with the same wave speeds in a finite range of parameters. Our results are further discussed in the light of possible biological relevance and ecological implications.
Higher order criterion for the nonexistence of formal first integral for nonlinear systems
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Zhiguo Xu
2017-11-01
Full Text Available The main purpose of this article is to find a criterion for the nonexistence of formal first integrals for nonlinear systems under general resonance. An algorithm illustrates an application to a class of generalized Lokta-Volterra systems. Our result generalize the classical Poincare's nonintegrability theorem and the existing results in the literature.
Fan, M; Wang, K; Jiang, D
1999-08-01
In this paper, we study the existence and global attractivity of positive periodic solutions of periodic n-species Lotka-Volterra competition systems. By using the method of coincidence degree and Lyapunov functional, a set of easily verifiable sufficient conditions are derived for the existence of at least one strictly positive (componentwise) periodic solution of periodic n-species Lotka-Volterra competition systems with several deviating arguments and the existence of a unique globally asymptotically stable periodic solution with strictly positive components of periodic n-species Lotka-Volterra competition system with several delays. Some new results are obtained. As an application, we also examine some special cases of the system we considered, which have been studied extensively in the literature. Some known results are improved and generalized.
Stability in distribution of a stochastic hybrid competitive Lotka–Volterra model with Lévy jumps
International Nuclear Information System (INIS)
Zhao, Yu; Yuan, Sanling
2016-01-01
Stability in distribution, implying the existence of the invariant probability measure, is an important measure of stochastic hybrid system. However, the effect of Lévy jumps on the stability in distribution is still unclear. In this paper, we consider a n-species competitive Lotka–Volterra model with Lévy jumps under regime-switching. First, we prove the existence of the global positive solution, obtain the upper and lower boundedness. Then, asymptotic stability in distribution as the main result of our paper is derived under some sufficient conditions. Finally, numerical simulations are carried out to support our theoretical results and a brief discussion is given.
International Nuclear Information System (INIS)
Castellanos, Víctor; Chan-López, Ramón E.
2017-01-01
In this paper we analyze a three level trophic chain model, considering a logistic growth for the lowest trophic level, a Lotka–Volterra and Holling type II functional responses for predators in the middle and in the cusp in the chain, respectively. The differential system is based on the Leslie–Gower scheme. We establish conditions on the parameters that guarantee the coexistence of populations in the habitat. We find that an Andronov–Hopf bifurcation takes place. The first Lyapunov coefficient is computed explicitly and we show the existence of a stable limit cycle. Numerically, we observe a strange attractor and there exist evidence of the model to exhibit chaotic dynamics.
International Nuclear Information System (INIS)
Monte, Luigi
2009-01-01
The present work describes a model for predicting the population dynamics of the main components (resources and consumers) of terrestrial ecosystems exposed to ionising radiation. The ecosystem is modelled by the Lotka-Volterra equations with consumer competition. Linear dose-response relationships without threshold are assumed to relate the values of the model parameters to the dose rates. The model accounts for the migration of consumers from areas characterised by different levels of radionuclide contamination. The criteria to select the model parameter values are motivated by accounting for the results of the empirical studies of past decades. Examples of predictions for long-term chronic exposure are reported and discussed.
Competitive or weak cooperative stochastic Lotka-Volterra systems conditioned on non-extinction.
Cattiaux, Patrick; Méléard, Sylvie
2010-06-01
We are interested in the long time behavior of a two-type density-dependent biological population conditioned on non-extinction, in both cases of competition or weak cooperation between the two species. This population is described by a stochastic Lotka-Volterra system, obtained as limit of renormalized interacting birth and death processes. The weak cooperation assumption allows the system not to blow up. We study the existence and uniqueness of a quasi-stationary distribution, that is convergence to equilibrium conditioned on non-extinction. To this aim we generalize in two-dimensions spectral tools developed for one-dimensional generalized Feller diffusion processes. The existence proof of a quasi-stationary distribution is reduced to the one for a d-dimensional Kolmogorov diffusion process under a symmetry assumption. The symmetry we need is satisfied under a local balance condition relying the ecological rates. A novelty is the outlined relation between the uniqueness of the quasi-stationary distribution and the ultracontractivity of the killed semi-group. By a comparison between the killing rates for the populations of each type and the one of the global population, we show that the quasi-stationary distribution can be either supported by individuals of one (the strongest one) type or supported by individuals of the two types. We thus highlight two different long time behaviors depending on the parameters of the model: either the model exhibits an intermediary time scale for which only one type (the dominant trait) is surviving, or there is a positive probability to have coexistence of the two species.
Sehgal, V.; Lakhanpal, A.; Maheswaran, R.; Khosa, R.; Sridhar, Venkataramana
2018-01-01
This study proposes a wavelet-based multi-resolution modeling approach for statistical downscaling of GCM variables to mean monthly precipitation for five locations at Krishna Basin, India. Climatic dataset from NCEP is used for training the proposed models (Jan.'69 to Dec.'94) and are applied to corresponding CanCM4 GCM variables to simulate precipitation for the validation (Jan.'95-Dec.'05) and forecast (Jan.'06-Dec.'35) periods. The observed precipitation data is obtained from the India Meteorological Department (IMD) gridded precipitation product at 0.25 degree spatial resolution. This paper proposes a novel Multi-Scale Wavelet Entropy (MWE) based approach for clustering climatic variables into suitable clusters using k-means methodology. Principal Component Analysis (PCA) is used to obtain the representative Principal Components (PC) explaining 90-95% variance for each cluster. A multi-resolution non-linear approach combining Discrete Wavelet Transform (DWT) and Second Order Volterra (SoV) is used to model the representative PCs to obtain the downscaled precipitation for each downscaling location (W-P-SoV model). The results establish that wavelet-based multi-resolution SoV models perform significantly better compared to the traditional Multiple Linear Regression (MLR) and Artificial Neural Networks (ANN) based frameworks. It is observed that the proposed MWE-based clustering and subsequent PCA, helps reduce the dimensionality of the input climatic variables, while capturing more variability compared to stand-alone k-means (no MWE). The proposed models perform better in estimating the number of precipitation events during the non-monsoon periods whereas the models with clustering without MWE over-estimate the rainfall during the dry season.
Frank, T. D.
The Lotka-Volterra-Haken equations have been frequently used in ecology and pattern formation. Recently, the equations have been proposed by several research groups as amplitude equations for task-related patterns of brain activity. In this theoretical study, the focus is on the circular causality aspect of pattern formation systems as formulated within the framework of synergetics. Accordingly, the stable modes of a pattern formation system inhibit the unstable modes, whereas the unstable modes excite the stable modes. Using this circular causality principle it is shown that under certain conditions the Lotka-Volterra-Haken amplitude equations can be derived from a general model of brain activity akin to the Wilson-Cowan model. The model captures the amplitude dynamics for brain activity patterns in experiments involving several consecutively performed multiple-choice tasks. This is explicitly demonstrated for two-choice tasks involving grasping and walking. A comment on the relevance of the theoretical framework for clinical psychology and schizophrenia is given as well.
Constructing New Discrete Integrable Coupling System for Soliton Equation by Kronecker Product
International Nuclear Information System (INIS)
Yu Fajun; Zhang Hongqing
2008-01-01
It is shown that the Kronecker product can be applied to constructing new discrete integrable coupling system of soliton equation hierarchy in this paper. A direct application to the fractional cubic Volterra lattice spectral problem leads to a novel integrable coupling system of soliton equation hierarchy. It is also indicated that the study of discrete integrable couplings by using the Kronecker product is an efficient and straightforward method. This method can be used generally
New integrable lattice hierarchies
International Nuclear Information System (INIS)
Pickering, Andrew; Zhu Zuonong
2006-01-01
In this Letter we give a new integrable four-field lattice hierarchy, associated to a new discrete spectral problem. We obtain our hierarchy as the compatibility condition of this spectral problem and an associated equation, constructed herein, for the time-evolution of eigenfunctions. We consider reductions of our hierarchy, which also of course admit discrete zero curvature representations, in detail. We find that our hierarchy includes many well-known integrable hierarchies as special cases, including the Toda lattice hierarchy, the modified Toda lattice hierarchy, the relativistic Toda lattice hierarchy, and the Volterra lattice hierarchy. We also obtain here a new integrable two-field lattice hierarchy, to which we give the name of Suris lattice hierarchy, since the first equation of this hierarchy has previously been given by Suris. The Hamiltonian structure of the Suris lattice hierarchy is obtained by means of a trace identity formula
International Nuclear Information System (INIS)
Prokhorov, L.V.
1982-01-01
Problems related to consideration of operator nonpermutability in Hamiltonian path integral (HPI) are considered in the review. Integrals are investigated using trajectories in configuration space (nonrelativistic quantum mechanics). Problems related to trajectory integrals in HPI phase space are discussed: the problem of operator nonpermutability consideration (extra terms problem) and corresponding equivalence rules; ambiguity of HPI usual recording; transition to curvilinear coordinates. Problem of quantization of dynamical systems with couplings has been studied. As in the case of canonical transformations, quantization of the systems with couplings of the first kind requires the consideration of extra terms
A geometrical method towards first integrals for dynamical systems
International Nuclear Information System (INIS)
Labrunie, S.; Conte, R.
1996-01-01
We develop a method, based on Darboux close-quote s and Liouville close-quote s works, to find first integrals and/or invariant manifolds for a physically relevant class of dynamical systems, without making any assumption on these elements close-quote forms. We apply it to three dynamical systems: Lotka endash Volterra, Lorenz and Rikitake. copyright 1996 American Institute of Physics
Directory of Open Access Journals (Sweden)
Zongyan Li
2016-01-01
Full Text Available This paper describes an improved global harmony search (IGHS algorithm for identifying the nonlinear discrete-time systems based on second-order Volterra model. The IGHS is an improved version of the novel global harmony search (NGHS algorithm, and it makes two significant improvements on the NGHS. First, the genetic mutation operation is modified by combining normal distribution and Cauchy distribution, which enables the IGHS to fully explore and exploit the solution space. Second, an opposition-based learning (OBL is introduced and modified to improve the quality of harmony vectors. The IGHS algorithm is implemented on two numerical examples, and they are nonlinear discrete-time rational system and the real heat exchanger, respectively. The results of the IGHS are compared with those of the other three methods, and it has been verified to be more effective than the other three methods on solving the above two problems with different input signals and system memory sizes.
Directory of Open Access Journals (Sweden)
Haiyan Yuan
2013-01-01
Full Text Available This paper introduces the stability and convergence of two-step Runge-Kutta methods with compound quadrature formula for solving nonlinear Volterra delay integro-differential equations. First, the definitions of (k,l-algebraically stable and asymptotically stable are introduced; then the asymptotical stability of a (k,l-algebraically stable two-step Runge-Kutta method with 0
International Nuclear Information System (INIS)
Liu Xianning; Chen Lansun
2003-01-01
This paper develops the Holling type II Lotka-Volterra predator-prey system, which may inherently oscillate, by introducing periodic constant impulsive immigration of predator. Condition for the system to be extinct is given and permanence condition is established via the method of comparison involving multiple Liapunov functions. Further influences of the impulsive perturbations on the inherent oscillation are studied numerically, which shows that with the increasing of the amount of the immigration, the system experiences process of quasi-periodic oscillating→cycles→periodic doubling cascade→chaos→periodic halfing cascade→cycles, which is characterized by (1) quasi-periodic oscillating, (2) period doubling, (3) period halfing, (4) non-unique dynamics, meaning that several attractors coexist
Makeev, Alexei G; Kurkina, Elena S; Kevrekidis, Ioannis G
2012-06-01
Kinetic Monte Carlo simulations are used to study the stochastic two-species Lotka-Volterra model on a square lattice. For certain values of the model parameters, the system constitutes an excitable medium: travelling pulses and rotating spiral waves can be excited. Stable solitary pulses travel with constant (modulo stochastic fluctuations) shape and speed along a periodic lattice. The spiral waves observed persist sometimes for hundreds of rotations, but they are ultimately unstable and break-up (because of fluctuations and interactions between neighboring fronts) giving rise to complex dynamic behavior in which numerous small spiral waves rotate and interact with each other. It is interesting that travelling pulses and spiral waves can be exhibited by the model even for completely immobile species, due to the non-local reaction kinetics.
DEFF Research Database (Denmark)
Emerek, Ruth
2004-01-01
Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...
Reduction theorems for weighted integral inequalities on the cone of monotone functions
International Nuclear Information System (INIS)
Gogatishvili, A; Stepanov, V D
2013-01-01
This paper surveys results related to the reduction of integral inequalities involving positive operators in weighted Lebesgue spaces on the real semi-axis and valid on the cone of monotone functions, to certain more easily manageable inequalities valid on the cone of non-negative functions. The case of monotone operators is new. As an application, a complete characterization for all possible integrability parameters is obtained for a number of Volterra operators. Bibliography: 118 titles
Gómez Rodríguez, Rafael Ángel
2014-01-01
To say that someone possesses integrity is to claim that that person is almost predictable about responses to specific situations, that he or she can prudentially judge and to act correctly. There is a closed interrelationship between integrity and autonomy, and the autonomy rests on the deeper moral claim of all humans to integrity of the person. Integrity has two senses of significance for medical ethic: one sense refers to the integrity of the person in the bodily, psychosocial and intellectual elements; and in the second sense, the integrity is the virtue. Another facet of integrity of the person is la integrity of values we cherish and espouse. The physician must be a person of integrity if the integrity of the patient is to be safeguarded. The autonomy has reduced the violations in the past, but the character and virtues of the physician are the ultimate safeguard of autonomy of patient. A field very important in medicine is the scientific research. It is the character of the investigator that determines the moral quality of research. The problem arises when legitimate self-interests are replaced by selfish, particularly when human subjects are involved. The final safeguard of moral quality of research is the character and conscience of the investigator. Teaching must be relevant in the scientific field, but the most effective way to teach virtue ethics is through the example of the a respected scientist.
Setting and solving several factorization problems for integral operators
International Nuclear Information System (INIS)
Engibaryan, N B
2000-01-01
The problem of factorization I-K=(I-U - )(I-U + ), is considered. Here I is the identity operator, K is a fixed integral operator of Fredholm type: (Kf)(x)=∫ a b k(x,t)f(t)dt, -∞≤a ± are unknown upper and lower Volterra operators. Classes of generalized Volterra operators U ± are introduced such that I-U ± are not necessarily invertible operators in the spaces of functions on (a,b) under consideration. A combination of the method of non-linear factorization equations and a priori estimates brings forth new results on the existence and properties of the solution to this problem for k≥0, both in the subcritical case μ + and U - vanish on some parts S - and S + of the domain S=(a,b) 2 such that S + union S - =S
Integral equation for Coulomb problem
International Nuclear Information System (INIS)
Sasakawa, T.
1986-01-01
For short range potentials an inhomogeneous (homogeneous) Lippmann-Schwinger integral equation of the Fredholm type yields the wave function of scattering (bound) state. For the Coulomb potential, this statement is no more valid. It has been felt difficult to express the Coulomb wave function in a form of an integral equation with the Coulomb potential as the perturbation. In the present paper, the author shows that an inhomogeneous integral equation of a Volterra type with the Coulomb potential as the perturbation can be constructed both for the scattering and the bound states. The equation yielding the binding energy is given in an integral form. The present treatment is easily extended to the coupled Coulomb problems
Langa, José A.; Rodríguez-Bernal, Aníbal; Suárez, Antonio
In this paper we study in detail the geometrical structure of global pullback and forwards attractors associated to non-autonomous Lotka-Volterra systems in all the three cases of competition, symbiosis or prey-predator. In particular, under some conditions on the parameters, we prove the existence of a unique nondegenerate global solution for these models, which attracts any other complete bounded trajectory. Thus, we generalize the existence of a unique strictly positive stable (stationary) solution from the autonomous case and we extend to Lotka-Volterra systems the result for scalar logistic equations. To this end we present the sub-supertrajectory tool as a generalization of the now classical sub-supersolution method. In particular, we also conclude pullback and forwards permanence for the above models.
Energy Technology Data Exchange (ETDEWEB)
Zhang Yu, E-mail: yuzhang@xmu.edu.cn [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Sprecher, Alicia J. [Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States); Zhao Zongxi [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Jiang, Jack J. [Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States)
2011-09-15
Highlights: > The VWK method effectively detects the nonlinearity of a discrete map. > The method describes the chaotic time series of a biomechanical vocal fold model. > Nonlinearity in laryngeal pathology is detected from short and noisy time series. - Abstract: In this paper, we apply the Volterra-Wiener-Korenberg (VWK) model method to detect nonlinearity in disordered voice productions. The VWK method effectively describes the nonlinearity of a third-order nonlinear map. It allows for the analysis of short and noisy data sets. The extracted VWK model parameters show an agreement with the original nonlinear map parameters. Furthermore, the VWK mode method is applied to successfully assess the nonlinearity of a biomechanical voice production model simulating irregular vibratory dynamics of vocal folds with a unilateral vocal polyp. Finally, we show the clinical applicability of this nonlinear detection method to analyze the electroglottographic data generated by 14 patients with vocal nodules or polyps. The VWK model method shows potential in describing the nonlinearity inherent in disordered voice productions from short and noisy time series that are common in the clinical setting.
International Nuclear Information System (INIS)
Zhang Yu; Sprecher, Alicia J.; Zhao Zongxi; Jiang, Jack J.
2011-01-01
Highlights: → The VWK method effectively detects the nonlinearity of a discrete map. → The method describes the chaotic time series of a biomechanical vocal fold model. → Nonlinearity in laryngeal pathology is detected from short and noisy time series. - Abstract: In this paper, we apply the Volterra-Wiener-Korenberg (VWK) model method to detect nonlinearity in disordered voice productions. The VWK method effectively describes the nonlinearity of a third-order nonlinear map. It allows for the analysis of short and noisy data sets. The extracted VWK model parameters show an agreement with the original nonlinear map parameters. Furthermore, the VWK mode method is applied to successfully assess the nonlinearity of a biomechanical voice production model simulating irregular vibratory dynamics of vocal folds with a unilateral vocal polyp. Finally, we show the clinical applicability of this nonlinear detection method to analyze the electroglottographic data generated by 14 patients with vocal nodules or polyps. The VWK model method shows potential in describing the nonlinearity inherent in disordered voice productions from short and noisy time series that are common in the clinical setting.
DEFF Research Database (Denmark)
Olwig, Karen Fog
2011-01-01
, while the countries have adopted disparate policies and ideologies, differences in the actual treatment and attitudes towards immigrants and refugees in everyday life are less clear, due to parallel integration programmes based on strong similarities in the welfare systems and in cultural notions...... of equality in the three societies. Finally, it shows that family relations play a central role in immigrants’ and refugees’ establishment of a new life in the receiving societies, even though the welfare society takes on many of the social and economic functions of the family....
International Nuclear Information System (INIS)
Jang, T. S.; Kwon, S. H.; Han, S. L.
2009-01-01
A novel procedure is proposed to identify the functional form of nonlinear restoring forces in the nonlinear oscillatory motion of a conservative system. Although the problem of identification has a unique solution, formulation results in a Volterra-type of integral equation of the 'first' kind: the solution lacks stability because the integral equation is the 'first' kind. Thus, the new problem at hand is ill-posed. Inevitable small errors during the identification procedure can make the prediction of nonlinear restoring forces useless. We overcome the difficulty by using a stabilization technique of Landweber's regularization in this study. The capability of the proposed procedure is investigated through numerical examples
International Nuclear Information System (INIS)
Tsai, Bi-Huei; Chang, Chih-Jen; Chang, Chun-Hsien
2016-01-01
By using the Lotka–Volterra model, this work examines for the first time the feasibility of using low-carbon energy to reduce fossil fuel consumption in the United States and, ultimately, to decrease CO_2 emissions. The research sample in this work consists of data on energy consumption and CO_2 emissions in the United States. Parameter estimation results reveal that although the consumption of low-carbon energy increases the consumption of fossil fuels, the latter does not affect the former. Low-carbon energy usage, including nuclear energy and solar photovoltaic power, increases fossil fuel consumption because the entire lifetime of a nuclear or solar energy facility, from the construction of electricity plants to decommissioning, consumes tremendous amounts of fossil fuels. This result verifies the infeasibility of low-carbon energy to replace fossil fuels under the current mining technology, electricity generation skills and governmental policy in the United States and explains why the United States refused to become a signatory of the Kyoto Protocol. Equilibrium analysis results indicate that the annual consumption of fossil fuels will ultimately exceed that of low-carbon energy by 461%. Since our proposed Lotka–Volterra model accurately predicts the consumption and CO_2 emission of different energy sources, this work contributes to the energy policies. - Highlights: • Our Lotka–Volterra model accurately predicts consumption of different energy sources. • We find the current infeasibility of using low-carbon energy to reduce fossil fuels. • The set-up of nuclear and solar plants increases fossil fuel usage in the U.S. • The consumption of fossil fuels will exceed that of low-carbon energy by 435%. • United States government prefers economic development over environmental protection.
Complete factorisation and analytic solutions of generalized Lotka-Volterra equations
Brenig, L.
1988-11-01
It is shown that many systems of nonlinear differential equations of interest in various fields are naturally imbedded in a new family of differential equations. This family is invariant under nonlinear transformations based on the concept of matrix power of a vector. Each equation belonging to that family can be brought into a factorized canonical form for which integrable cases can be easily identified and solutions can be found by quadratures.
Beretta, E; Capasso, V; Rinaldi, F
1988-01-01
The paper contains an extension of the general ODE system proposed in previous papers by the same authors, to include distributed time delays in the interaction terms. The new system describes a large class of Lotka-Volterra like population models and epidemic models with continuous time delays. Sufficient conditions for the boundedness of solutions and for the global asymptotic stability of nontrivial equilibrium solutions are given. A detailed analysis of the epidemic system is given with respect to the conditions for global stability. For a relevant subclass of these systems an existence criterion for steady states is also given.
International Nuclear Information System (INIS)
Tsuchida, Takayuki
2010-01-01
We propose a new method for discretizing the time variable in integrable lattice systems while maintaining the locality of the equations of motion. The method is based on the zero-curvature (Lax pair) representation and the lowest-order 'conservation laws'. In contrast to the pioneering work of Ablowitz and Ladik, our method allows the auxiliary dependent variables appearing in the stage of time discretization to be expressed locally in terms of the original dependent variables. The time-discretized lattice systems have the same set of conserved quantities and the same structures of the solutions as the continuous-time lattice systems; only the time evolution of the parameters in the solutions that correspond to the angle variables is discretized. The effectiveness of our method is illustrated using examples such as the Toda lattice, the Volterra lattice, the modified Volterra lattice, the Ablowitz-Ladik lattice (an integrable semi-discrete nonlinear Schroedinger system) and the lattice Heisenberg ferromagnet model. For the modified Volterra lattice, we also present its ultradiscrete analogue.
Liouvillian integrability of gravitating static isothermal fluid spheres
International Nuclear Information System (INIS)
Iacono, Roberto; Llibre, Jaume
2014-01-01
We examine the integrability properties of the Einstein field equations for static, spherically symmetric fluid spheres, complemented with an isothermal equation of state, ρ = np. In this case, Einstein's equations can be reduced to a nonlinear, autonomous second order ordinary differential equation (ODE) for m/R (m is the mass inside the radius R) that has been solved analytically only for n = −1 and n = −3, yielding the cosmological solutions by De Sitter and Einstein, respectively, and for n = −5, case for which the solution can be derived from the De Sitter's one using a symmetry of Einstein's equations. The solutions for these three cases are of Liouvillian type, since they can be expressed in terms of elementary functions. Here, we address the question of whether Liouvillian solutions can be obtained for other values of n. To do so, we transform the second order equation into an equivalent autonomous Lotka–Volterra quadratic polynomial differential system in R 2 , and characterize the Liouvillian integrability of this system using Darboux theory. We find that the Lotka–Volterra system possesses Liouvillian first integrals for n = −1, −3, −5, which descend from the existence of invariant algebraic curves of degree one, and for n = −6, a new solvable case, associated to an invariant algebraic curve of higher degree (second). For any other value of n, eventual first integrals of the Lotka–Volterra system, and consequently of the second order ODE for the mass function must be non-Liouvillian. This makes the existence of other solutions of the isothermal fluid sphere problem with a Liouvillian metric quite unlikely
Liouvillian integrability of gravitating static isothermal fluid spheres
Energy Technology Data Exchange (ETDEWEB)
Iacono, Roberto, E-mail: roberto.iacono@enea.it [ENEA-C. R. Casaccia, Via Anguillarese 301, 00123 Roma (Italy); Llibre, Jaume, E-mail: jllibre@mat.uab.cat [Departament de Matemàtiques, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Catalonia (Spain)
2014-10-01
We examine the integrability properties of the Einstein field equations for static, spherically symmetric fluid spheres, complemented with an isothermal equation of state, ρ = np. In this case, Einstein's equations can be reduced to a nonlinear, autonomous second order ordinary differential equation (ODE) for m/R (m is the mass inside the radius R) that has been solved analytically only for n = -1 and n = -3, yielding the cosmological solutions by De Sitter and Einstein, respectively, and for n = -5, case for which the solution can be derived from the De Sitter's one using a symmetry of Einstein's equations. The solutions for these three cases are of Liouvillian type, since they can be expressed in terms of elementary functions. Here, we address the question of whether Liouvillian solutions can be obtained for other values of n. To do so, we transform the second order equation into an equivalent autonomous Lotka–Volterra quadratic polynomial differential system in R² and characterize the Liouvillian integrability of this system using Darboux theory. We find that the Lotka–Volterra system possesses Liouvillian first integrals for n = -1, -3, -5, which descend from the existence of invariant algebraic curves of degree one, and for n = -6, a new solvable case, associated to an invariant algebraic curve of higher degree (second). For any other value of n, eventual first integrals of the Lotka–Volterra system, and consequently of the second order ODE for the mass function must be non-Liouvillian. This makes the existence of other solutions of the isothermal fluid sphere problem with a Liouvillian metric quite unlikely.
Diagnosis of soft faults in analog integrated circuits based on fractional correlation
International Nuclear Information System (INIS)
Deng Yong; Shi Yibing; Zhang Wei
2012-01-01
Aiming at the problem of diagnosing soft faults in analog integrated circuits, an approach based on fractional correlation is proposed. First, the Volterra series of the circuit under test (CUT) decomposed by the fractional wavelet packet are used to calculate the fractional correlation functions. Then, the calculated fractional correlation functions are used to form the fault signatures of the CUT. By comparing the fault signatures, the different soft faulty conditions of the CUT are identified and the faults are located. Simulations of benchmark circuits illustrate the proposed method and validate its effectiveness in diagnosing soft faults in analog integrated circuits. (semiconductor integrated circuits)
Directory of Open Access Journals (Sweden)
Teresa Nolesini
2016-09-01
Full Text Available Volterra (Central Italy is a town of great historical interest, due to its vast and well-preserved cultural heritage, including a 2.6 km long Etruscan-medieval wall enclosure representing one of the most important elements. Volterra is located on a clayey hilltop prone to landsliding, soil erosion, therefore the town is subject to structural deterioration. During 2014, two impressive collapses occurred on the wall enclosure in the southwestern urban sector. Following these events, a monitoring campaign was carried out by means of remote sensing techniques, such as space-borne (PS-InSAR and ground-based (GB-InSAR radar interferometry, in order to analyze the displacements occurring both in the urban area and the surrounding slopes, and therefore to detect possible critical sectors with respect to instability phenomena. Infrared thermography (IRT was also applied with the aim of detecting possible criticalities on the wall-enclosure, with special regards to moisture and seepage areas. PS-InSAR data allowed a stability back-monitoring on the area, revealing 19 active clusters displaying ground velocity higher than 10 mm/year in the period 2011–2015. The GB-InSAR system detected an acceleration up to 1.7 mm/h in near-real time as the March 2014 failure precursor. The IRT technique, employed on a double survey campaign, in both dry and rainy conditions, permitted to acquire 65 thermograms covering 23 sectors of the town wall, highlighting four thermal anomalies. The outcomes of this work demonstrate the usefulness of different remote sensing technologies for deriving information in risk prevention and management, and the importance of choosing the appropriate technology depending on the target, time sampling and investigation scale. In this paper, the use of a multi-platform remote sensing system permitted technical support of the local authorities and conservators, providing a comprehensive overview of the Volterra site, its cultural heritage and
Certain new unified integrals associated with the product of generalized Bessel functions
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Praveen Agarwal
2016-02-01
Full Text Available Our focus to presenting two very general integral formulas whose integrands are the integrand given in the Oberhettinger's integral formula and a finite product of the generalized Bessel function of the first kind, which are expressed in terms of the generalized Lauricella functions. Among a large number of interesting and potentially useful special cases of our main results, some integral formulas involving such elementary functions are also considered.
Dynamics, integrability and topology for some classes of Kolmogorov Hamiltonian systems in R+4
Llibre, Jaume; Xiao, Dongmei
2017-02-01
In this paper we first give the sufficient and necessary conditions in order that two classes of polynomial Kolmogorov systems in R+4 are Hamiltonian systems. Then we study the integrability of these Hamiltonian systems in the Liouville sense. Finally, we investigate the global dynamics of the completely integrable Lotka-Volterra Hamiltonian systems in R+4. As an application of the invariant subsets of these systems, we obtain topological classifications of the 3-submanifolds in R+4 defined by the hypersurfaces axy + bzw + cx2 y + dxy2 + ez2 w + fzw2 = h, where a , b , c , d , e , f , w and h are real constants.
Numerical treatments for solving nonlinear mixed integral equation
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M.A. Abdou
2016-12-01
Full Text Available We consider a mixed type of nonlinear integral equation (MNLIE of the second kind in the space C[0,T]×L2(Ω,T<1. The Volterra integral terms (VITs are considered in time with continuous kernels, while the Fredholm integral term (FIT is considered in position with singular general kernel. Using the quadratic method and separation of variables method, we obtain a nonlinear system of Fredholm integral equations (NLSFIEs with singular kernel. A Toeplitz matrix method, in each case, is then used to obtain a nonlinear algebraic system. Numerical results are calculated when the kernels take a logarithmic form or Carleman function. Moreover, the error estimates, in each case, are then computed.
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Zhen Liu
2017-11-01
Full Text Available The insulated gate bipolar transistor (IGBT is a kind of excellent performance switching device used widely in power electronic systems. How to estimate the remaining useful life (RUL of an IGBT to ensure the safety and reliability of the power electronics system is currently a challenging issue in the field of IGBT reliability. The aim of this paper is to develop a prognostic technique for estimating IGBTs’ RUL. There is a need for an efficient prognostic algorithm that is able to support in-situ decision-making. In this paper, a novel prediction model with a complete structure based on optimally pruned extreme learning machine (OPELM and Volterra series is proposed to track the IGBT’s degradation trace and estimate its RUL; we refer to this model as Volterra k-nearest neighbor OPELM prediction (VKOPP model. This model uses the minimum entropy rate method and Volterra series to reconstruct phase space for IGBTs’ ageing samples, and a new weight update algorithm, which can effectively reduce the influence of the outliers and noises, is utilized to establish the VKOPP network; then a combination of the k-nearest neighbor method (KNN and least squares estimation (LSE method is used to calculate the output weights of OPELM and predict the RUL of the IGBT. The prognostic results show that the proposed approach can predict the RUL of IGBT modules with small error and achieve higher prediction precision and lower time cost than some classic prediction approaches.
Hamiltonian structures and integrability for a discrete coupled KdV-type equation hierarchy
International Nuclear Information System (INIS)
Zhao Haiqiong; Zhu Zuonong; Zhang Jingli
2011-01-01
Coupled Korteweg-de Vries (KdV) systems have many important physical applications. By considering a 4 × 4 spectral problem, we derive a discrete coupled KdV-type equation hierarchy. Our hierarchy includes the coupled Volterra system proposed by Lou et al. (e-print arXiv: 0711.0420) as the first member which is a discrete version of the coupled KdV equation. We also investigate the integrability in the Liouville sense and the multi-Hamiltonian structures for the obtained hierarchy. (authors)
On the factorization of integral operators on spaces of summable functions
International Nuclear Information System (INIS)
Engibaryan, Norayr B
2009-01-01
We consider the factorization I-K=(I-U + )(I-U - ), where I is the identity operator, K is an integral operator acting on some Banach space of functions summable with respect to a measure μ on (a,b) subset of (-∞,+∞) continuous relative to the Lebesgue measure, (Kf)(x)=∫ a b k(x,t)f(t)μ(dt), x element of (a,b), and U ± are the desired Volterra operators. A necessary and sufficient condition is found for the existence of this factorization for a rather wide class of operators K with positive kernels and for Hilbert-Schmidt operators.
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Shunxi Li
2017-01-01
Full Text Available The potential demand of battery electric vehicle (BEV is the base of the decision-making to the government policy formulation, enterprise manufacture capacity expansion, and charging infrastructure construction. How to predict the future amount of BEV accurately is very important to the development of BEV both in practice and in theory. The present paper tries to compare the short-term accuracy of a proposed modified Bass model and Lotka-Volterra (LV model, by taking China’s BEV development as the case study. Using the statistics data of China’s BEV amount of 21 months from Jan 2015 to Sep 2016, we compare the simulation accuracy based on the value of mean absolute percentage error (MAPE and discuss the forecasting capacity of the two models according to China’s government expectation. According to the MAPE value, the two models have good prediction accuracy, but the Bass model is more accurate than LV model. Bass model has only one dimension and focuses on the diffusion trend, while LV model has two dimensions and mainly describes the relationship and competing process between the two populations. In future research, the forecasting advantages of Bass model and LV model should be combined to get more accurate predicting effect.
Benetti, G L; Dini, M
1990-01-01
It was made a screening on children of some filter classes (1st and 3d class of primary school and 1st class of secondary school) of the Volterra's schools to estimate the incidence of caries and, if necessary, to activate programs for an adequate prevention. We examined 749 children arrived to the Dental Department of the Sanitary District owing an invitation letter; a set of question was given to their parents testing mainly alimentary and oral hygienic uses of the children examined by dentists. Elaboration of data obtained from replies and demonstrated that caries incidence in our population is of 65.29%, prevailing on male sex, and that this pathology is predominant on people taking insufficient care of oral hygiene, making no use of fluoridated toothpaste and eating any of cakes (especially between meals). These data show the high incidence of caries in evolutional age and how much this is strictly connected with wrong alimentary and hygienic uses. Therefore, to reduce this phenomenon, it's necessary to operate interventions of sanitary education and dental checking examinations, at least every 6-12 months, beginning in preschool age.
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Silvia Bianchini
2015-04-01
Full Text Available In recent years, space-borne InSAR (interferometric synthetic aperture radar techniques have shown their capabilities to provide precise measurements of Earth surface displacements for monitoring natural processes. Landslides threaten human lives and structures, especially in urbanized areas, where the density of elements at risk sensitive to ground movements is high. The methodology described in this paper aims at detecting terrain motions and building deformations at the local scale, by means of satellite radar data combined with in situ validation campaigns. The proposed approach consists of deriving maximum settlement directions of the investigated buildings from displacement data revealed by radar measurements and then in the cross-comparison of these values with background geological data, constructive features and on-field evidence. This validation permits better understanding whether or not the detected movements correspond to visible and effective damages to buildings. The method has been applied to the southwestern sector of Volterra (Tuscany region, Italy, which is a landslide-affected and partially urbanized area, through the use of COSMO-SkyMed satellite images as input data. Moreover, we discuss issues and possible misinterpretations when dealing with PSI (Persistent Scatterer Interferometry data referring to single manufactures and the consequent difficulty of attributing the motion rate to ground displacements, rather than to structural failures.
Exactly and completely integrable nonlinear dynamical systems
International Nuclear Information System (INIS)
Leznov, A.N.; Savel'ev, M.V.
1987-01-01
The survey is devoted to a consitent exposition of the group-algebraic methods for the integration of systems of nonlinear partial differential equations possessing a nontrivial internal symmetry algebra. Samples of exactly and completely integrable wave and evolution equations are considered in detail, including generalized (periodic and finite nonperiodic Toda lattice, nonlinear Schroedinger, Korteweg-de Vries, Lotka-Volterra equations, etc.) For exactly integrable systems the general solutions of the Cauchy and Goursat problems are given in an explicit form, while for completely integrable systems an effective method for the construction of their soliton solutions is developed. Application of the developed methods to a differential geometry problem of classification of the integrable manifolds embeddings is discussed. For exactly integrable systems the supersymmetric extensions are constructed. By the example of the generalized Toda lattice a quantization scheme is developed. It includes an explicit derivation of the corresponding Heisenberg operators and their desription in terms of the quantum algebras of the Hopf type. Among multidimensional systems the four-dimensional self-dual Yang-Mills equations are investigated most attentively with a goal of constructing their general solutions
Block-pulse functions approach to numerical solution of Abel’s integral equation
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Monireh Nosrati Sahlan
2015-12-01
Full Text Available This study aims to present a computational method for solving Abel’s integral equation of the second kind. The introduced method is based on the use of Block-pulse functions (BPFs via collocation method. Abel’s integral equations as singular Volterra integral equations are hard and heavy in computation, but because of the properties of BPFs, as is reported in examples, this method is more efficient and more accurate than some other methods for solving this class of integral equations. On the other hand, the benefit of this method is low cost of computing operations. The applied method transforms the singular integral equation into triangular linear algebraic system that can be solved easily. An error analysis is worked out and applications are demonstrated through illustrative examples.
On the complete and partial integrability of non-Hamiltonian systems
Bountis, T. C.; Ramani, A.; Grammaticos, B.; Dorizzi, B.
1984-11-01
The methods of singularity analysis are applied to several third order non-Hamiltonian systems of physical significance including the Lotka-Volterra equations, the three-wave interaction and the Rikitake dynamo model. Complete integrability is defined and new completely integrable systems are discovered by means of the Painlevé property. In all these cases we obtain integrals, which reduce the equations either to a final quadrature or to an irreducible second order ordinary differential equation (ODE) solved by Painlevé transcendents. Relaxing the Painlevé property we find many partially integrable cases whose movable singularities are poles at leading order, with In( t- t0) terms entering at higher orders. In an Nth order, generalized Rössler model a precise relation is established between the partial fulfillment of the Painlevé conditions and the existence of N - 2 integrals of the motion.
Wilson, William G; Lundberg, Per
2004-09-22
Theoretical interest in the distributions of species abundances observed in ecological communities has focused recently on the results of models that assume all species are identical in their interactions with one another, and rely upon immigration and speciation to promote coexistence. Here we examine a one-trophic level system with generalized species interactions, including species-specific intraspecific and interspecific interaction strengths, and density-independent immigration from a regional species pool. Comparisons between results from numerical integrations and an approximate analytic calculation for random communities demonstrate good agreement, and both approaches yield abundance distributions of nearly arbitrary shape, including bimodality for intermediate immigration rates.
Marichev-Saigo-Maeda fractional integration operators of the Bassel functions
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Sunil D. Purohit
2012-05-01
Full Text Available In this paper, we apply generalized operators of fractional integration involving Appell’s function F_3 (. due to Marichev-Saigo-Maeda, to the Bessel function of first kind. The results are expressed in terms of generalized Wright function and hypergeometric functions _pF_q . Special cases involving this function are mentioned. Results given recently by Kilbas and Sebastian follow as special cases of the theorems establish here.
International Nuclear Information System (INIS)
Ballestra, Luca Vincenzo; Pacelli, Graziella; Radi, Davide
2016-01-01
We deal with the problem of pricing barrier options on an underlying described by the mixed fractional Brownian model. To this aim, we consider the initial-boundary value partial differential problem that yields the option price and we derive an integral representation of it in which the integrand functions must be obtained solving Volterra equations of the first kind. In addition, we develop an ad-hoc numerical procedure to solve the integral equations obtained. Numerical simulations reveal that the proposed method is extremely accurate and fast, and performs significantly better than the finite difference method.
Certain fractional integral formulas involving the product of generalized Bessel functions.
Baleanu, D; Agarwal, P; Purohit, S D
2013-01-01
We apply generalized operators of fractional integration involving Appell's function F 3(·) due to Marichev-Saigo-Maeda, to the product of the generalized Bessel function of the first kind due to Baricz. The results are expressed in terms of the multivariable generalized Lauricella functions. Corresponding assertions in terms of Saigo, Erdélyi-Kober, Riemann-Liouville, and Weyl type of fractional integrals are also presented. Some interesting special cases of our two main results are presented. We also point out that the results presented here, being of general character, are easily reducible to yield many diverse new and known integral formulas involving simpler functions.
Certain Fractional Integral Formulas Involving the Product of Generalized Bessel Functions
Baleanu, D.; Agarwal, P.; Purohit, S. D.
2013-01-01
We apply generalized operators of fractional integration involving Appell's function F 3(·) due to Marichev-Saigo-Maeda, to the product of the generalized Bessel function of the first kind due to Baricz. The results are expressed in terms of the multivariable generalized Lauricella functions. Corresponding assertions in terms of Saigo, Erdélyi-Kober, Riemann-Liouville, and Weyl type of fractional integrals are also presented. Some interesting special cases of our two main results are presented. We also point out that the results presented here, being of general character, are easily reducible to yield many diverse new and known integral formulas involving simpler functions. PMID:24379745
Energy Technology Data Exchange (ETDEWEB)
Mancas, Stefan C. [Department of Mathematics, Embry–Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Apdo Postal 3-74 Tangamanga, 78231 San Luis Potosí, SLP (Mexico)
2013-09-02
We emphasize two connections, one well known and another less known, between the dissipative nonlinear second order differential equations and the Abel equations which in their first-kind form have only cubic and quadratic terms. Then, employing an old integrability criterion due to Chiellini, we introduce the corresponding integrable dissipative equations. For illustration, we present the cases of some integrable dissipative Fisher, nonlinear pendulum, and Burgers–Huxley type equations which are obtained in this way and can be of interest in applications. We also show how to obtain Abel solutions directly from the factorization of second order nonlinear equations.
On the algebra of deformed differential operators, and induced integrable Toda field theory
International Nuclear Information System (INIS)
Hssaini, M.; Kessabi, M.; Maroufi, B.; Sedra, M.B.
2000-07-01
We build in this paper the algebra of q-deformed pseudo-differential operators shown to be an essential step towards setting a q-deformed integrability program. In fact, using the results of this q-deformed algebra, we derive the q-analogues of the generalised KdV hierarchy. We focus in particular the first leading orders of this q-deformed hierarchy namely the q-KdV and q-Boussinesq integrable systems. We also present the q-generalisation of the conformal transformations of the currents u n , n ≥ 2 and discuss the primary condition of the fields w n , n ≥ 2 by using the Volterra gauge group transformations for the q-covariant Lax operators. An induced su(n)-Toda(su(2)-Liouville) field theory construction is discussed and other important features are presented. (author)
On the asymptotic solution to a class of linear integral equations
International Nuclear Information System (INIS)
Gautesen, A.K.
1988-01-01
The authors consider Fredholm integral equations of the first kind whose kernels are a function of the difference between two points times a large parameter. Conditions on the kernel are stated in terms of a function corresponding to a Wiener-Hopf factorization of the Fourier transform of the kernel. They give the complete asymptotic expansions of the solution to the integral equations. As applications of the author's results, the author considers the steady-state, acoustical scattering of a plane wave by both a hard strip and a soft strip. The author's results are uniform with respect to the direction of incidence
Lagrangian structures, integrability and chaos for 3D dynamical equations
International Nuclear Information System (INIS)
Bustamante, Miguel D; Hojman, Sergio A
2003-01-01
In this paper, we consider the general setting for constructing action principles for three-dimensional first-order autonomous equations. We present the results for some integrable and non-integrable cases of the Lotka-Volterra equation, and show Lagrangian descriptions which are valid for systems satisfying Shil'nikov criteria on the existence of strange attractors, though chaotic behaviour has not been verified up to now. The Euler-Lagrange equations we get for these systems usually present 'time reparametrization' invariance, though other kinds of invariance may be found according to the kernel of the associated symplectic 2-form. The formulation of a Hamiltonian structure (Poisson brackets and Hamiltonians) for these systems from the Lagrangian viewpoint leads to a method of finding new constants of the motion starting from known ones, which is applied to some systems found in the literature known to possess a constant of the motion, to find the other and thus showing their integrability. In particular, we show that the so-called ABC system is completely integrable if it possesses one constant of the motion
Covariant path integrals on hyperbolic surfaces
Schaefer, Joe
1997-11-01
DeWitt's covariant formulation of path integration [B. De Witt, "Dynamical theory in curved spaces. I. A review of the classical and quantum action principles," Rev. Mod. Phys. 29, 377-397 (1957)] has two practical advantages over the traditional methods of "lattice approximations;" there is no ordering problem, and classical symmetries are manifestly preserved at the quantum level. Applying the spectral theorem for unbounded self-adjoint operators, we provide a rigorous proof of the convergence of certain path integrals on Riemann surfaces of constant curvature -1. The Pauli-DeWitt curvature correction term arises, as in DeWitt's work. Introducing a Fuchsian group Γ of the first kind, and a continuous, bounded, Γ-automorphic potential V, we obtain a Feynman-Kac formula for the automorphic Schrödinger equation on the Riemann surface ΓH. We analyze the Wick rotation and prove the strong convergence of the so-called Feynman maps [K. D. Elworthy, Path Integration on Manifolds, Mathematical Aspects of Superspace, edited by Seifert, Clarke, and Rosenblum (Reidel, Boston, 1983), pp. 47-90] on a dense set of states. Finally, we give a new proof of some results in C. Grosche and F. Steiner, "The path integral on the Poincare upper half plane and for Liouville quantum mechanics," Phys. Lett. A 123, 319-328 (1987).
Integral or integrated marketing
Directory of Open Access Journals (Sweden)
Davčik Nebojša
2006-01-01
Full Text Available Marketing theorists and experts try to develop business efficient organization and to get marketing performance at higher, business integrated level since its earliest beginnings. The core issue in this paperwork is the dialectic and practical approach dilemma should we develop integrated or integral marketing approach in the organization. The presented company cases as well as dialectic and functional explanations of this dilemma clearly shows that integrated marketing is narrower approach than integral marketing if we take as focal point new, unique and completed entity. In the integration the essence is in getting different parts together, which do not have to make necessary the new entity. The key elements in the definition of the integral marketing are necessity and holistic, e.g. necessity to develop new, holistic entity.
Iterative and iterative-noniterative integral solutions in 3-loop massive QCD calculations
International Nuclear Information System (INIS)
Ablinger, J.; Radu, C.S.; Schneider, C.; Behring, A.; Imamoglu, E.; Van Hoeij, M.; Von Manteuffel, A.; Raab, C.G.
2017-11-01
Various of the single scale quantities in massless and massive QCD up to 3-loop order can be expressed by iterative integrals over certain classes of alphabets, from the harmonic polylogarithms to root-valued alphabets. Examples are the anomalous dimensions to 3-loop order, the massless Wilson coefficients and also different massive operator matrix elements. Starting at 3-loop order, however, also other letters appear in the case of massive operator matrix elements, the so called iterative non-iterative integrals, which are related to solutions based on complete elliptic integrals or any other special function with an integral representation that is definite but not a Volterra-type integral. After outlining the formalism leading to iterative non-iterative integrals,we present examples for both of these cases with the 3-loop anomalous dimension γ (2) qg and the structure of the principle solution in the iterative non-interative case of the 3-loop QCD corrections to the ρ-parameter.
Iterative and iterative-noniterative integral solutions in 3-loop massive QCD calculations
Energy Technology Data Exchange (ETDEWEB)
Ablinger, J.; Radu, C.S.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Behring, A. [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Teilchenphysik und Kosmologie; Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Imamoglu, E.; Van Hoeij, M. [Florida State Univ., Tallahassee, FL (United States). Dept. of Mathematics; Von Manteuffel, A. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Raab, C.G. [Johannes Kepler Univ., Linz (Austria). Inst. for Algebra
2017-11-15
Various of the single scale quantities in massless and massive QCD up to 3-loop order can be expressed by iterative integrals over certain classes of alphabets, from the harmonic polylogarithms to root-valued alphabets. Examples are the anomalous dimensions to 3-loop order, the massless Wilson coefficients and also different massive operator matrix elements. Starting at 3-loop order, however, also other letters appear in the case of massive operator matrix elements, the so called iterative non-iterative integrals, which are related to solutions based on complete elliptic integrals or any other special function with an integral representation that is definite but not a Volterra-type integral. After outlining the formalism leading to iterative non-iterative integrals,we present examples for both of these cases with the 3-loop anomalous dimension γ{sup (2)}{sub qg} and the structure of the principle solution in the iterative non-interative case of the 3-loop QCD corrections to the ρ-parameter.
FUNPACK-2, Subroutine Library, Bessel Function, Elliptical Integrals, Min-max Approximation
International Nuclear Information System (INIS)
Cody, W.J.; Garbow, Burton S.
1975-01-01
1 - Description of problem or function: FUNPACK is a collection of FORTRAN subroutines to evaluate certain special functions. The individual subroutines are (Identification/Description): NATSI0 F2I0 Bessel function I 0 ; NATSI1 F2I1 Bessel function I 1 ; NATSJ0 F2J0 Bessel function J 0 ; NATSJ1 F2J1 Bessel function J 1 ; NATSK0 F2K0 Bessel function K 0 ; NATSK1 F2K1 Bessel function K 1 ; NATSBESY F2BY Bessel function Y ν ; DAW F1DW Dawson's integral; DELIPK F1EK Complete elliptic integral of the first kind; DELIPE F1EE Complete elliptic integral of the second kind; DEI F1EI Exponential integrals; NATSPSI F2PS Psi (logarithmic derivative of gamma function); MONERR F1MO Error monitoring package . 2 - Method of solution: FUNPACK uses evaluation of min-max approximations
Integral-preserving integrators
International Nuclear Information System (INIS)
McLaren, D I; Quispel, G R W
2004-01-01
Ordinary differential equations having a first integral may be solved numerically using one of several methods, with the integral preserved to machine accuracy. One such method is the discrete gradient method. It is shown here that the order of the method can be bootstrapped repeatedly to higher orders of accuracy. The method is illustrated using the Henon-Heiles system. (letter to the editor)
Solution of the Stokes system by boundary integral equations and fixed point iterative schemes
International Nuclear Information System (INIS)
Chidume, C.E.; Lubuma, M.S.
1990-01-01
The solution to the exterior three dimensional Stokes problem is sought in the form of a single layer potential of unknown density. This reduces the problem to a boundary integral equation of the first kind whose operator is the velocity component of the single layer potential. It is shown that this component is an isomorphism between two appropriate Sobolev spaces containing the unknown densities and the data respectively. The isomorphism corresponds to a variational problem with coercive bilinear form. The latter property allows us to consider various fixed point iterative schemes that converge to the unique solution of the integral equation. Explicit error estimates are also obtained. The successive approximations are also considered in a more computable form by using the product integration method of Atkinson. (author). 47 refs
Integral equation models for image restoration: high accuracy methods and fast algorithms
International Nuclear Information System (INIS)
Lu, Yao; Shen, Lixin; Xu, Yuesheng
2010-01-01
Discrete models are consistently used as practical models for image restoration. They are piecewise constant approximations of true physical (continuous) models, and hence, inevitably impose bottleneck model errors. We propose to work directly with continuous models for image restoration aiming at suppressing the model errors caused by the discrete models. A systematic study is conducted in this paper for the continuous out-of-focus image models which can be formulated as an integral equation of the first kind. The resulting integral equation is regularized by the Lavrentiev method and the Tikhonov method. We develop fast multiscale algorithms having high accuracy to solve the regularized integral equations of the second kind. Numerical experiments show that the methods based on the continuous model perform much better than those based on discrete models, in terms of PSNR values and visual quality of the reconstructed images
Preconditioning first and second kind integral formulations of the capacitance problem
Energy Technology Data Exchange (ETDEWEB)
Tausch, J.; White, J.
1996-12-31
Engineering programs which compute electrostatic capacitances for complicated arrangements of conductors commonly set up the electrostatic potential u as a superposition of surface carges {sigma} u(x) = {integral}{sub s}G(x, y){sigma}(y) dS(y). Where G(x, y) = {1/4}{pi}{vert_bar}x - y{vert_bar} is the Green`s function for the Laplacian in the three-space. For a specified potential on the conductor surface(s) S, this approach leads to an integral equation of the first kind on S for the charge density {sigma}. The capacitance is the net-charge on the conductors and is given by the surface integral of {sigma}.
Integral Transport Analysis Results for Ions Flowing Through Neutral Gas
Emmert, Gilbert; Santarius, John
2017-10-01
Results of a computational model for the flow of energetic ions and neutrals through a background neutral gas will be presented. The method models reactions as creating a new source of ions or neutrals if the energy or charge state of the resulting particle is changed. For a given source boundary condition, the creation and annihilation of the various species is formulated as a 1-D Volterra integral equation that can quickly be solved numerically by finite differences. The present work focuses on multiple-pass, 1-D ion flow through neutral gas and a nearly transparent, concentric anode and cathode pair in spherical, cylindrical, or linear geometry. This has been implemented as a computer code for atomic (3He, 3He +, 3He + +) and molecular (D, D2, D-, D +, D2 +, D3 +) ion and neutral species, and applied to modeling inertial-electrostatic connement (IEC) devices. The code yields detailed energy spectra of the various ions and energetic neutral species. Calculations for several University of Wisconsin IEC and ion implantation devices will be presented. Research supported by US Dept. of Homeland Security Grant 2015-DN-077-ARI095, Dept. of Energy Grant DE-FG02-04ER54745, and the Grainger Foundation.
Covariant path integrals on hyperbolic surfaces
International Nuclear Information System (INIS)
Schaefer, J.
1997-01-01
DeWitt close-quote s covariant formulation of path integration [B. De Witt, open-quotes Dynamical theory in curved spaces. I. A review of the classical and quantum action principles,close quotes Rev. Mod. Phys. 29, 377 endash 397 (1957)] has two practical advantages over the traditional methods of open-quotes lattice approximations;close quotes there is no ordering problem, and classical symmetries are manifestly preserved at the quantum level. Applying the spectral theorem for unbounded self-adjoint operators, we provide a rigorous proof of the convergence of certain path integrals on Riemann surfaces of constant curvature -1. The Pauli endash DeWitt curvature correction term arises, as in DeWitt close-quote s work. Introducing a Fuchsian group Γ of the first kind, and a continuous, bounded, Γ-automorphic potential V, we obtain a Feynman endash Kac formula for the automorphic Schroedinger equation on the Riemann surface Γ backslash H. We analyze the Wick rotation and prove the strong convergence of the so-called Feynman maps [K. D. Elworthy, Path Integration on Manifolds, Mathematical Aspects of Superspace, edited by Seifert, Clarke, and Rosenblum (Reidel, Boston, 1983), pp. 47 endash 90] on a dense set of states. Finally, we give a new proof of some results in C. Grosche and F. Steiner, open-quotes The path integral on the Poincare upper half plane and for Liouville quantum mechanics,close quotes Phys. Lett. A 123, 319 endash 328 (1987). copyright 1997 American Institute of Physics
International Nuclear Information System (INIS)
Bratton, T.J.
1992-01-01
This article offers ideas for evaluating integrated solid waste management systems through the use of a conceptual cost overview. The topics of the article include the integrated solid waste management system; making assumptions about community characteristics, waste generation rates, waste collection responsibility, integrated system components, sizing and economic life of system facilities, system implementation schedule, facility ownership, and system administration; integrated system costs; integrated system revenues; system financing; cost projections; and making decisions
Energy Technology Data Exchange (ETDEWEB)
Bustamante, Miguel D [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile (Chile); Hojman, Sergio A [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile (Chile)
2003-01-10
In this paper, we consider the general setting for constructing action principles for three-dimensional first-order autonomous equations. We present the results for some integrable and non-integrable cases of the Lotka-Volterra equation, and show Lagrangian descriptions which are valid for systems satisfying Shil'nikov criteria on the existence of strange attractors, though chaotic behaviour has not been verified up to now. The Euler-Lagrange equations we get for these systems usually present 'time reparametrization' invariance, though other kinds of invariance may be found according to the kernel of the associated symplectic 2-form. The formulation of a Hamiltonian structure (Poisson brackets and Hamiltonians) for these systems from the Lagrangian viewpoint leads to a method of finding new constants of the motion starting from known ones, which is applied to some systems found in the literature known to possess a constant of the motion, to find the other and thus showing their integrability. In particular, we show that the so-called ABC system is completely integrable if it possesses one constant of the motion.
A Nonlinear Hyperbolic Volterra Equation in Viscoelasticity.
1980-06-01
states that k(t) e L (0,-) if -nd only if (3.7) P(Z) def .’’(3.7) P(z) d ;’(0) + ’(0)a’(z) = X( 0 ) + (0)za(z) does not vanish on the half plane Rez ; 0...For w(t,x) e X(M,T), (2.5) and the Poincare inequality yield (2.6) w 2 (t,x) + w2x(t,x) + w 2(t,x) ( M , 0 4 t ( T, 0 4 x ( I x tx xx We now consider...2.6), the Poincare inequality and Schwarz’s inequality, every term on the right-hand side of (2.12), (2.15), and (2.16) can be majorized by one of p
Directory of Open Access Journals (Sweden)
Coghetto Roland
2017-10-01
Full Text Available Some authors have formalized the integral in the Mizar Mathematical Library (MML. The first article in a series on the Darboux/Riemann integral was written by Noboru Endou and Artur Korniłowicz: [6]. The Lebesgue integral was formalized a little later [13] and recently the integral of Riemann-Stieltjes was introduced in the MML by Keiko Narita, Kazuhisa Nakasho and Yasunari Shidama [12].
Gumral, Hasan
Poisson structure of completely integrable 3 dimensional dynamical systems can be defined in terms of an integrable 1-form. We take advantage of this fact and use the theory of foliations in discussing the geometrical structure underlying complete and partial integrability. We show that the Halphen system can be formulated in terms of a flat SL(2,R)-valued connection and belongs to a non-trivial Godbillon-Vey class. On the other hand, for the Euler top and a special case of 3-species Lotka-Volterra equations which are contained in the Halphen system as limiting cases, this structure degenerates into the form of globally integrable bi-Hamiltonian structures. The globally integrable bi-Hamiltonian case is a linear and the sl_2 structure is a quadratic unfolding of an integrable 1-form in 3 + 1 dimensions. We complete the discussion of the Hamiltonian structure of 2-component equations of hydrodynamic type by presenting the Hamiltonian operators for Euler's equation and a continuum limit of Toda lattice. We present further infinite sequences of conserved quantities for shallow water equations and show that their generalizations by Kodama admit bi-Hamiltonian structure. We present a simple way of constructing the second Hamiltonian operators for N-component equations admitting some scaling properties. The Kodama reduction of the dispersionless-Boussinesq equations and the Lax reduction of the Benney moment equations are shown to be equivalent by a symmetry transformation. They can be cast into the form of a triplet of conservation laws which enable us to recognize a non-trivial scaling symmetry. The resulting bi-Hamiltonian structure generates three infinite sequences of conserved densities.
Thomas, E. G. F.
2012-01-01
This paper deals with the theory of integration of scalar functions with respect to a measure with values in a, not necessarily locally convex, topological vector space. It focuses on the extension of such integrals from bounded measurable functions to the class of integrable functions, proving
Bustamante, M D
2003-01-01
In this paper, we consider the general setting for constructing action principles for three-dimensional first-order autonomous equations. We present the results for some integrable and non-integrable cases of the Lotka-Volterra equation, and show Lagrangian descriptions which are valid for systems satisfying Shil'nikov criteria on the existence of strange attractors, though chaotic behaviour has not been verified up to now. The Euler-Lagrange equations we get for these systems usually present 'time reparametrization' invariance, though other kinds of invariance may be found according to the kernel of the associated symplectic 2-form. The formulation of a Hamiltonian structure (Poisson brackets and Hamiltonians) for these systems from the Lagrangian viewpoint leads to a method of finding new constants of the motion starting from known ones, which is applied to some systems found in the literature known to possess a constant of the motion, to find the other and thus showing their integrability. In particular, w...
Interorganisational Integration
DEFF Research Database (Denmark)
Lyngsø, Anne Marie; Godtfredsen, Nina Skavlan; Frølich, Anne
2016-01-01
INTRODUCTION: Despite many initiatives to improve coordination of patient pathways and intersectoral cooperation, Danish health care is still fragmented, lacking intra- and interorganisational integration. This study explores barriers to and facilitators of interorganisational integration...... at a university hospital in the Capital Region of Denmark. RESULTS AND DISCUSSION: Our results can be grouped into five influencing areas for interorganisational integration: communication/information transfer, committed leadership, patient engagement, the role and competencies of the general practitioner...... and organisational culture. Proposed solutions to barriers in each area hold the potential to improve care integration as experienced by individuals responsible for supporting and facilitating it. Barriers and facilitators to integrating care relate to clinical, professional, functional and normative integration...
International Nuclear Information System (INIS)
Antill, N.
1999-01-01
This paper focuses on the trend in international energy companies towards vertical integration in the gas chain from wellhead to power generation, horizontal integration in refining and marketing businesses, and the search for larger projects with lower upstream costs. The shape of the petroleum industry in the next millennium, the creation of super-major oil companies, and the relationship between size and risk are discussed. The dynamics of vertical integration, present events and future developments are considered. (UK)
Moiseiwitsch, B L
2005-01-01
Two distinct but related approaches hold the solutions to many mathematical problems--the forms of expression known as differential and integral equations. The method employed by the integral equation approach specifically includes the boundary conditions, which confers a valuable advantage. In addition, the integral equation approach leads naturally to the solution of the problem--under suitable conditions--in the form of an infinite series.Geared toward upper-level undergraduate students, this text focuses chiefly upon linear integral equations. It begins with a straightforward account, acco
DEFF Research Database (Denmark)
Lenau, Torben Anker
1999-01-01
A homepage on the internet with course material, lecture plan, student exercises, etc. Continuesly updated during the course Integrated Design (80402, 80403)......A homepage on the internet with course material, lecture plan, student exercises, etc. Continuesly updated during the course Integrated Design (80402, 80403)...
DEFF Research Database (Denmark)
Axelsson, Runo
2013-01-01
Background: In Sweden, as in many other countries, there has been a succession of trends in the organisation of health care and other welfare services. These trends have had different implications for the integration of services in the health and welfare system. Aims: One aim is to discuss...... the implications of different organisational trends for the integration of health and welfare services. Another aim is to introduce a Swedish model of financial coordination as a flexible way to organise integration. Organisational trends: In the 1960’s there was an expansion of health and welfare services leading...... an increasing lack of integration in the health and welfare system. In the 2000’s, there has been a re-centralisation through mergers of hospitals, regions and state agencies. It has become clear, however, that mergers do not promote integration but rather increase the bureaucratisation of the system. Model...
Bauböck, Rainer
1995-01-01
from the Table of Contents: Migration and integration - Basic concepts and definitions; Immigration and Integration policies; The legal framework for integration; Dimension of social integration; Cultural integration; Conclusions;
Kozarić-Kovacić, Dragica
2008-09-01
The main purposes of the article are to present the history of integration in psychotherapy, the reasons of the development integrative approaches, and the approaches to integration in psychotherapy. Three approaches to integration in psychotherapy exist: theoretical integration, theoretical eclecticism, and common factors in different psychotherapeutic trends. In integrative psychotherapy, the basic epistemology, theory, and clinical practice are based on the phenomenology, field theory, holism, dialogue, and co-creation of dialogue in the therapeutic relationship. The main criticism is that integrative psychotherapy suffers from confusion and many unresolved controversies. It is difficult to theoretically and methodologically define the clinically applied model that is based on such a different epistemological and theoretical presumptions. Integrative psychotherapy is a synthesis of humanistic psychotherapy, object relations theory, and psychoanalytical self psychology. It focuses on the dynamics and potentials of human relationships, with a goal of changing the relations and understanding internal and external resistances. The process of integrative psychotherapy is primarily focused on the developmental-relational model and co-creation of psychotherapeutic relationship as a single interactive event, which is not unilateral, but rather a joint endeavor by both the therapist and the patient/client. The need for a relationship is an important human need and represents a process of attunement that occurs as a response to the need for a relationship, a unique interpersonal contact between two people. If this need is not met, it manifests with the different feelings and various defenses. To meet this need, we need to have another person with whom we can establish a sensitive, attuned relationship. Thus, the therapist becomes this person who tries to supplement what the person did not receive. Neuroscience can be a source of integration through different therapies. We
Integration of Chandrasekhar's integral equation
International Nuclear Information System (INIS)
Tanaka, Tasuku
2003-01-01
We solve Chandrasekhar's integration equation for radiative transfer in the plane-parallel atmosphere by iterative integration. The primary thrust in radiative transfer has been to solve the forward problem, i.e., to evaluate the radiance, given the optical thickness and the scattering phase function. In the area of satellite remote sensing, our problem is the inverse problem: to retrieve the surface reflectance and the optical thickness of the atmosphere from the radiance measured by satellites. In order to retrieve the optical thickness and the surface reflectance from the radiance at the top-of-the atmosphere (TOA), we should express the radiance at TOA 'explicitly' in the optical thickness and the surface reflectance. Chandrasekhar formalized radiative transfer in the plane-parallel atmosphere in a simultaneous integral equation, and he obtained the second approximation. Since then no higher approximation has been reported. In this paper, we obtain the third approximation of the scattering function. We integrate functions derived from the second approximation in the integral interval from 1 to ∞ of the inverse of the cos of zenith angles. We can obtain the indefinite integral rather easily in the form of a series expansion. However, the integrals at the upper limit, ∞, are not yet known to us. We can assess the converged values of those series expansions at ∞ through calculus. For integration, we choose coupling pairs to avoid unnecessary terms in the outcome of integral and discover that the simultaneous integral equation can be deduced to the mere integral equation. Through algebraic calculation, we obtain the third approximation as a polynomial of the third degree in the atmospheric optical thickness
International Nuclear Information System (INIS)
Chafcouloff, S.; Michel, G.; Trice, M.; Clark, G.; Cosad, C.; Forbes, K.
1995-01-01
Integrated services is the name given to several services grouped together under a single contract. Four key factors determine the success of integrated services projects: teamwork, common objectives, technology, and shared benefits. For oil companies, integration means smoother, more efficient operations by bringing service companies on board as part of the team. For the service industry, it means a radical change in the way business is conducted, taking on more responsibility in return for greater incentives. This article reviews the need for change and the approach Schlumberger has adopted to meet this challenge. 20 figs., 20 refs
Energy Technology Data Exchange (ETDEWEB)
Chafcouloff, S.; Michel, G.; Trice, M. [Schlumberger Integrated Project Management Group, Montrouge (France); Clark, G. [Schlumberger Testing Services, Aberdeen (United Kingdom); Cosad, C.; Forbes, K. [Schlumberger Integrated Project Management Group, Aberdeen (United Kingdom)
1995-12-31
Integrated services is the name given to several services grouped together under a single contract. Four key factors determine the success of integrated services projects: teamwork, common objectives, technology, and shared benefits. For oil companies, integration means smoother, more efficient operations by bringing service companies on board as part of the team. For the service industry, it means a radical change in the way business is conducted, taking on more responsibility in return for greater incentives. This article reviews the need for change and the approach Schlumberger has adopted to meet this challenge. 20 figs., 20 refs
Directory of Open Access Journals (Sweden)
Lioara-Bianca BUBOIU
2015-04-01
Full Text Available Accepting and valuing people with disabilities is a key aspect of social policies promoted worldwide. The implementation of these policies aim normalize the lives of people with disabilities through full integration in the society to which they belong. Removing discrimination and social barriers equates to a maturing of the society, maturing translated by accepting diversity that surrounds us. Each person must be appreciated at its true value regardless of its condition of normality or deviation from it. Valuing individuals can be achieved only through a full acceptance in society, by assigning statuses and fulfilling social roles. School integration of children with special educational needs in mainstream education is a challenge and involves many aspects to be successful. It is the premise of social integration, the basis for future socio-professional insertion. Integrated education is the first step towards a world of equal opportunities, a world without discrimination.
DEFF Research Database (Denmark)
Knudsen, Lars Ramkilde; Wagner, David
2002-01-01
This paper considers a cryptanalytic approach called integral cryptanalysis. It can be seen as a dual to differential cryptanalysis and applies to ciphers not vulnerable to differential attacks. The method is particularly applicable to block ciphers which use bijective components only.......This paper considers a cryptanalytic approach called integral cryptanalysis. It can be seen as a dual to differential cryptanalysis and applies to ciphers not vulnerable to differential attacks. The method is particularly applicable to block ciphers which use bijective components only....
Hankel complementary integral transformations of arbitrary order
Directory of Open Access Journals (Sweden)
M. Linares Linares
1992-01-01
Full Text Available Four selfreciprocal integral transformations of Hankel type are defined through(ℋi,μf(y=Fi(y=∫0∞αi(xℊi,μ(xyf(xdx, ℋi,μ−1=ℋi,μ,where i=1,2,3,4; μ≥0; α1(x=x1+2μ, ℊ1,μ(x=x−μJμ(x, Jμ(x being the Bessel function of the first kind of order μ; α2(x=x1−2μ, ℊ2,μ(x=(−1μx2μℊ1,μ(x; α3(x=x−1−2μ, ℊ3,μ(x=x1+2μℊ1,μ(x, and α4(x=x−1+2μ, ℊ4,μ(x=(−1μxℊ1,μ(x. The simultaneous use of transformations ℋ1,μ, and ℋ2,μ, (which are denoted by ℋμ allows us to solve many problems of Mathematical Physics involving the differential operator Δμ=D2+(1+2μx−1D, whereas the pair of transformations ℋ3,μ and ℋ4,μ, (which we express by ℋμ* permits us to tackle those problems containing its adjoint operator Δμ*=D2−(1+2μx−1D+(1+2μx−2, no matter what the real value of μ be. These transformations are also investigated in a space of generalized functions according to the mixed Parseval equation∫0∞f(xg(xdx=∫0∞(ℋμf(y(ℋμ*g(ydy,which is now valid for all real μ.
Siemieniuch, C E; Sinclair, M A
2006-01-01
The paper presents a view of systems integration, from an ergonomics/human factors perspective, emphasising the process of systems integration as is carried out by humans. The first section discusses some of the fundamental issues in systems integration, such as the significance of systems boundaries, systems lifecycle and systems entropy, issues arising from complexity, the implications of systems immortality, and so on. The next section outlines various generic processes for executing systems integration, to act as guides for practitioners. These address both the design of the system to be integrated and the preparation of the wider system in which the integration will occur. Then the next section outlines some of the human-specific issues that would need to be addressed in such processes; for example, indeterminacy and incompleteness, the prediction of human reliability, workload issues, extended situation awareness, and knowledge lifecycle management. For all of these, suggestions and further readings are proposed. Finally, the conclusions section reiterates in condensed form the major issues arising from the above.
Cartier, Pierre; DeWitt-Morette, Cecile
2010-06-01
Acknowledgements; List symbols, conventions, and formulary; Part I. The Physical and Mathematical Environment: 1. The physical and mathematical environment; Part II. Quantum Mechanics: 2. First lesson: gaussian integrals; 3. Selected examples; 4. Semiclassical expansion: WKB; 5. Semiclassical expansion: beyond WKB; 6. Quantum dynamics: path integrals and operator formalism; Part III. Methods from Differential Geometry: 7. Symmetries; 8. Homotopy; 9. Grassmann analysis: basics; 10. Grassmann analysis: applications; 11. Volume elements, divergences, gradients; Part IV. Non-Gaussian Applications: 12. Poisson processes in physics; 13. A mathematical theory of Poisson processes; 14. First exit time: energy problems; Part V. Problems in Quantum Field Theory: 15. Renormalization 1: an introduction; 16. Renormalization 2: scaling; 17. Renormalization 3: combinatorics; 18. Volume elements in quantum field theory Bryce DeWitt; Part VI. Projects: 19. Projects; Appendix A. Forward and backward integrals: spaces of pointed paths; Appendix B. Product integrals; Appendix C. A compendium of gaussian integrals; Appendix D. Wick calculus Alexander Wurm; Appendix E. The Jacobi operator; Appendix F. Change of variables of integration; Appendix G. Analytic properties of covariances; Appendix H. Feynman's checkerboard; Bibliography; Index.
Directory of Open Access Journals (Sweden)
Ruzanna Kh. Makaova
2017-12-01
Full Text Available In this paper we study the boundary value problem for a degenerating third order equation of hyperbolic type in a mixed domain. The equation under consideration in the positive part of the domain coincides with the Hallaire equation, which is a pseudoparabolic type equation. Moreover, in the negative part of the domain it coincides with a degenerating hyperbolic equation of the first kind, the particular case of the Bitsadze–Lykov equation. The existence and uniqueness theorem for the solution is proved. The uniqueness of the solution to the problem is proved with the Tricomi method. Using the functional relationships of the positive and negative parts of the domain on the degeneration line, we arrive at the convolution type Volterra integral equation of the 2nd kind with respect to the desired solution by a derivative trace. With the Laplace transform method, we obtain the solution of the integral equation in its explicit form. At last, the solution to the problem under study is written out explicitly as the solution of the second boundary-value problem in the positive part of the domain for the Hallaire equation and as the solution to the Cauchy problem in the negative part of the domain for a degenerate hyperbolic equation of the first kind.
DEFF Research Database (Denmark)
Petersson, Eva
2005-01-01
the theoretical foundations of play and learning. In this presentation, we explore pedagogical potentials of new technologies and traditional toys integrated into a physical and virtual toy (hereinafter called integrated toy) with specific focus on the open-ended toy and non-formal learning. The integrated toy......Toys play a crucial role in supporting children’s learning and creation of meaning in their everyday life. Children also play with toys out of an interest to interact with others e.g. peers and adults. Tendencies of digital technology in toys have led to greater opportunities for manipulation...... and interaction supporting children’s play and learning such that technology is ever-present in the play environments of children. Although electronics have been deployed in tools for play and learning, most of it has facilitated individual learning. Computer games, for instance, most often are designed...
DEFF Research Database (Denmark)
Merlo, Domenico Franco; Vahakangas, Kirsi; Knudsen, Lisbeth E.
2008-01-01
consent was obtained.Integrity is central to environmental health research searching for causal relations. It requires open communication and trust and any violation (i.e., research misconduct, including fabrication or falsification of data, plagiarism, conflicting interests, etc.) may endanger...
2006-01-01
St. John Health consists of nine hospitals throughout southern Michigan. Recently, in an attempt to brand the system as the state's premiere place for medical services, the system launched 'Real Medicine', a campaign that brands all nine hospitals together. Using print, radio, and television spots, the effort also integrates direct mail collateral and brochures to reach consumers.
Harris, Robert; Smids, Annejoke; Kors, Ninja
2007-01-01
This is an article about the integration of instrumental teaching, aural skills and keyboard skills and music theory at the pre-tertiary level. Team teaching and discipline crossover offer a possible solution to students’ inability to apply skills taught by specialists in separate fields. A personal
Energy Technology Data Exchange (ETDEWEB)
Bailey, David H.; Borwein, Jonathan M.; Crandall, Richard E.
2006-06-01
By a "box integral" we mean here an expectation $\\langle|\\vec r - \\vec q|^s \\rangle$ where $\\vec r$runs over the unit $n$-cube,with $\\vec q$ and $s$ fixed, explicitly:\\begin eqnarray*&&\\int_01 \\cdots \\int_01 \\left((r_1 - q_1)2 + \\dots+(r_n-q_n)2\\right)^ s/2 \\ dr_1 \\cdots dr_n.\\end eqnarray* The study ofbox integrals leads one naturally into several disparate fields ofanalysis. While previous studies have focused upon symbolic evaluationand asymptotic analysis of special cases (notably $s = 1$), we workherein more generally--in interdisciplinary fashion--developing resultssuch as: (1) analytic continuation (in complex $s$), (2) relevantcombinatorial identities, (3) rapidly converging series, (4) statisticalinferences, (5) connections to mathematical physics, and (6)extreme-precision quadrature techniques appropriate for these integrals.These intuitions and results open up avenues of experimental mathematics,with a view to new conjectures and theorems on integrals of thistype.
A Comprehensive Review of Boundary Integral Formulations of Acoustic Scattering Problems
Directory of Open Access Journals (Sweden)
S.I. Zaman
2000-12-01
Full Text Available This is a review presenting an overview of the developments in boundary integral formulations of the acoustic scattering problems. Generally, the problem is formulated in one of two ways viz. Green’s representation formula, and the Layer-theoretic formulation utilizing either a simple-layer or a double-layer potential. The review presents and expounds the major contributions in this area over the last four decades. The need for a robust and improved formulation of the exterior scattering problem (Neumann or Dirichlet arose due to the fact that the classical formulation failed to yield a unique solution at (acoustic wave-numbers which correspond to eigenvalues (eigenfrequencies of the corresponding interior scattering problem. Moreover, this correlation becomes more pronounced as the wave-numbers become larger i.e. as the (acoustic frequency increases. The robust integral formulations which are discussed here yield Fredholms integral equations of the second kind which are more amenable to computation than the first kind. However, the integral equation involves a hypersingular kernel which creates ill-conditioning in the final matrix representation. This is circumvented by a regularisation technique. An extensive useful list of references is also presented here for researchers in this area.
DEFF Research Database (Denmark)
Jørgensen, Michael; Nielsen, M. W.; Strømann-Andersen, Jakob Bjørn
2011-01-01
and describe the decision process. Specific attention is given to how the engineering input was presented and how it was able to facilitate the design development. Site and context, building shape, organization of functions and HVAC-systems were all included to obtain a complete picture of the building......, low-energy consumption, and high-quality indoor environment. We use this case study to investigate how technical knowledge about building performance can be integrated into the conceptual design stage. We have selected certain points during the design process that represented design challenges...
Integral equation models for the inverse problem of biological ion channel distributions
International Nuclear Information System (INIS)
French, D A; Groetsch, C W
2007-01-01
Olfactory cilia are thin hair-like filaments that extend from olfactory receptor neurons into the nasal mucus. Transduction of an odor into an electrical signal is accomplished by a depolarizing influx of ions through cyclic-nucleotide-gated channels in the membrane that forms the lateral surface of the cilium. In an experimental procedure developed by S. Kleene, a cilium is detached at its base and drawn into a recording pipette. The cilium base is then immersed in a bath of a channel activating agent (cAMP) which is allowed to diffuse into the cilium interior, opening channels as it goes and initiating a transmembrane current. The total current is recorded as a function of time and serves as data for a nonlinear integral equation of the first kind modeling the spatial distribution of ion channels along the length of the cilium. We discuss some linear Fredholm integral equations that result from simplifications of this model. A numerical procedure is proposed for a class of integral equations suggested by this simplified model and numerical results using simulated and laboratory data are presented
International Nuclear Information System (INIS)
Hollaway, F.W.
1985-01-01
During 1984, all portions of the Nova control system that were necessary for the support of laser activation and completion of the Nova project were finished and placed in service on time. The Nova control system has been unique in providing, on schedule, the capabilities required in the central control room and in various local control areas throughout the facility. The ambitious goal of deploying this system early enough to use it as an aid in the activation of the laser was accomplished; thus the control system made a major contribution to the completion of Nova activation on schedule. Support and enhancement activities continued during the year on the VAX computer systems, central control room, operator consoles and displays, Novanet data communications network, system-level software for both the VAX and LSI-11 computers, Praxis control system computer language, software management tools, and the development system, which includes office terminals. Computational support was also supplied for a wide variety of test fixtures required by the optical and mechanical subsystems. Significant new advancements were made in four areas in integrated controls this year: the integration software (which includes the shot scheduler), the Praxis language, software quality assurance audit, and software development and data handling. A description of the accomplishments in each of these areas follows
Multidimensional singular integrals and integral equations
Mikhlin, Solomon Grigorievich; Stark, M; Ulam, S
1965-01-01
Multidimensional Singular Integrals and Integral Equations presents the results of the theory of multidimensional singular integrals and of equations containing such integrals. Emphasis is on singular integrals taken over Euclidean space or in the closed manifold of Liapounov and equations containing such integrals. This volume is comprised of eight chapters and begins with an overview of some theorems on linear equations in Banach spaces, followed by a discussion on the simplest properties of multidimensional singular integrals. Subsequent chapters deal with compounding of singular integrals
Warwick-Giles, Lynsey; Checkland, Kath
2018-03-19
Purpose The purpose of this paper is to try and understand how several organisations in one area in England are working together to develop an integrated care programme. Weick's (1995) concept of sensemaking is used as a lens to examine how the organisations are working collaboratively and maintaining the programme. Design/methodology/approach Qualitative methods included: non-participant observations of meetings, interviews with key stakeholders and the collection of documents relating to the programme. These provided wider contextual information about the programme. Comprehensive field notes were taken during observations and analysed alongside interview transcriptions using NVIVO software. Findings This paper illustrates the importance of the construction of a shared identity across all organisations involved in the programme. Furthermore, the wider policy discourse impacted on how the programme developed and influenced how organisations worked together. Originality/value The role of leaders from all organisations involved in the programme was of significance to the overall development of the programme and the sustained momentum behind the programme. Leaders were able to generate a "narrative of success" to drive the programme forward. This is of particular relevance to evaluators, highlighting the importance of using multiple methods to allow researchers to probe beneath the surface of programmes to ensure that evidence moves beyond this public narrative.
Directory of Open Access Journals (Sweden)
Yue-Qian Wu
2016-01-01
Full Text Available Former works show that the accuracy of the second-kind integral equations can be improved dramatically by using the rotated Buffa-Christiansen (BC functions as the testing functions, and sometimes their accuracy can be even better than the first-kind integral equations. When the rotated BC functions are used as the testing functions, the discretization error of the identity operators involved in the second-kind integral equations can be suppressed significantly. However, the sizes of spherical objects which were analyzed are relatively small. Numerical capability of the method of moments (MoM for solving integral equations with the rotated BC functions is severely limited. Hence, the performance of BC functions for accuracy improvement of electrically large objects is not studied. In this paper, the multilevel fast multipole algorithm (MLFMA is employed to accelerate iterative solution of the magnetic-field integral equation (MFIE. Then a series of numerical experiments are performed to study accuracy improvement of MFIE in perfect electric conductor (PEC cases with the rotated BC as testing functions. Numerical results show that the effect of accuracy improvement by using the rotated BC as the testing functions is greatly different with curvilinear or plane triangular elements but falls off when the size of the object is large.
Integrated project delivery : The designer as integrator
Wamelink, J.W.F.; Koolwijk, J.S.J.; van Doorn, A.J.
2012-01-01
Process innovation related to integrated project delivery is an important topic in the building industry. Studies on process innovation through the use of integrated contracts usually focus on contractors, and particularly on the possibility of forward integration into the building process. Three
Lui, M; Chan, Andy; Long, Josh
2011-01-01
Pro Spring Integration is an authoritative book from the experts that guides you through the vast world of enterprise application integration (EAI) and application of the Spring Integration framework towards solving integration problems. The book is:. * An introduction to the concepts of enterprise application integration * A reference on building event-driven applications using Spring Integration * A guide to solving common integration problems using Spring Integration What makes this book unique is its coverage of contemporary technologies and real-world information, with a focus on common p
Tactical Systems Integration Laboratory
Federal Laboratory Consortium — The Tactical Systems Integration Laboratory is used to design and integrate computer hardware and software and related electronic subsystems for tactical vehicles....
Černiavskaitė, Marija
2017-01-01
This Bachelor's thesis presents SAP CRM and integration systems testing analysis: investigation in SAP CRM and SAP PO systems, presentation of relationship between systems, introduction to third-party system (non-SAP) – Network Informational System (NIS) which has integration with SAP, presentation of best CRM testing practises, analysis and recommendation of integration testing. Practical integration testing is done in accordance to recommendations.
Energy Technology Data Exchange (ETDEWEB)
Guyt, J.; Macara, C.
1997-12-31
This paper focuses on some of the issues necessary for pipeline operators to consider when addressing the challenge of managing the integrity of their systems. Topics are: Definition; business justification; creation and safeguarding of technical integrity; control and deviation from technical integrity; pipelines; pipeline failure assessment; pipeline integrity assessment; leak detection; emergency response. 6 figs., 3 tabs.
Integral consideration of integrated management systems
International Nuclear Information System (INIS)
Frauenknecht, Stefan; Schmitz, Hans
2010-01-01
Aim of the project for the NPPs Kruemmel and Brunsbuettel (Vattenfall) is the integral view of the business process as basis for the implementation and operation of management systems in the domains quality, safety and environment. The authors describe the integral view of the business processes in the frame of integrated management systems with the focus nuclear safety, lessons learned in the past, the concept of a process-based controlling system and experiences from the practical realization.
International Nuclear Information System (INIS)
Arsenault, Louis-François; Millis, Andrew J; Neuberg, Richard; Hannah, Lauren A
2017-01-01
We present a supervised machine learning approach to the inversion of Fredholm integrals of the first kind as they arise, for example, in the analytic continuation problem of quantum many-body physics. The approach provides a natural regularization for the ill-conditioned inverse of the Fredholm kernel, as well as an efficient and stable treatment of constraints. The key observation is that the stability of the forward problem permits the construction of a large database of outputs for physically meaningful inputs. Applying machine learning to this database generates a regression function of controlled complexity, which returns approximate solutions for previously unseen inputs; the approximate solutions are then projected onto the subspace of functions satisfying relevant constraints. Under standard error metrics the method performs as well or better than the Maximum Entropy method for low input noise and is substantially more robust to increased input noise. We suggest that the methodology will be similarly effective for other problems involving a formally ill-conditioned inversion of an integral operator, provided that the forward problem can be efficiently solved. (paper)
International Nuclear Information System (INIS)
Werby, M.F.; Broadhead, M.K.; Strayer, M.R.; Bottcher, C.
1992-01-01
The Helmholtz-Poincarf Wave Equation (H-PWE) arises in many areas of classical wave scattering theory. In particular it can be found for the cases of acoustical scattering from submerged bounded objects and electromagnetic scattering from objects. The extended boundary integral equations (EBIE) method is derived from considering both the exterior and interior solutions of the H-PWECs. This coupled set of expressions has the advantage of not only offering a prescription for obtaining a solution for the exterior scattering problem, but it also obviates the problem of irregular values corresponding to fictitious interior eigenvalues. Once the coupled equations are derived, they can be obtained in matrix form by expanding all relevant terms in partial wave expansions, including a bi-orthogonal expansion of the Green's function. However some freedom in the choice of the surface expansion is available since the unknown surface quantities may be expanded in a variety of ways so long as closure is obtained. Out of many possible choices, we develop an optimal method to obtain such expansions which is based on the optimum eigenfunctions related to the surface of the object. In effect, we convert part of the problem (that associated with the Fredholms integral equation of the first kind) an eigenvalue problem of a related Hermitian operator. The methodology will be explained in detail and examples will be presented
Buried waste integrated demonstration technology integration process
International Nuclear Information System (INIS)
Ferguson, J.S.; Ferguson, J.E.
1992-04-01
A Technology integration Process was developed for the Idaho National Energy Laboratories (INEL) Buried Waste Integrated Demonstration (BWID) Program to facilitate the transfer of technology and knowledge from industry, universities, and other Federal agencies into the BWID; to successfully transfer demonstrated technology and knowledge from the BWID to industry, universities, and other Federal agencies; and to share demonstrated technologies and knowledge between Integrated Demonstrations and other Department of Energy (DOE) spread throughout the DOE Complex. This document also details specific methods and tools for integrating and transferring technologies into or out of the BWID program. The document provides background on the BWID program and technology development needs, demonstrates the direction of technology transfer, illustrates current processes for this transfer, and lists points of contact for prospective participants in the BWID technology transfer efforts. The Technology Integration Process was prepared to ensure compliance with the requirements of DOE's Office of Technology Development (OTD)
Power Systems Integration Laboratory | Energy Systems Integration Facility
| NREL Power Systems Integration Laboratory Power Systems Integration Laboratory Research in the Energy System Integration Facility's Power Systems Integration Laboratory focuses on the microgrid applications. Photo of engineers testing an inverter in the Power Systems Integration Laboratory
Food Web Assembly Rules for Generalized Lotka-Volterra Equations
DEFF Research Database (Denmark)
Härter, Jan Olaf Mirko; Mitarai, Namiko; Sneppen, Kim
2016-01-01
the lack of niches, corresponding to unpaired species. For the species richness at each trophic level, we derive the food web assembly rules, which specify sustainable combinations. In neighboring levels, these rules allow the higher level to avert competitive exclusion at the lower, thereby incorporating...
Profitless delays for extinction in nonautonomous Lotka-Volterra system
Liu, Shengqiang; Chen, Lansun
2001-12-01
We study the delayed periodic n-species Lotka-Voterra systems where the growth rate of each species is not always positive. The sufficient conditions for the extinction that are independent of the delays are obtained. Some known results are improved and generalized. Our results suggest that under some conditions, the introduction and the variance of the time delays can be both harmless and profitless. Discussion about the effect of time delays on the extinction of the system is also advanced.
Spatial organization in cyclic Lotka-Volterra systems
International Nuclear Information System (INIS)
Frachebourg, L.; Krapivsky, P.L.; Ben-Naim, E.
1996-01-01
We study the evolution of a system of N interacting species which mimics the dynamics of a cyclic food chain. On a one-dimensional lattice with N α , where α=3/4 (1/2) and 1/3 for N=3 with sequential (parallel) dynamics and N=4, respectively. The domain distribution also exhibits a self-similar spatial structure which is characterized by an additional length scale, left-angle L(t)right-angle ∼t β , with β=1 and 2/3 for N=3 and 4, respectively. For N≥5, the system quickly reaches a frozen state with noninteracting neighboring species. We investigate the time distribution of the number of mutations of a site using scaling arguments as well as an exact solution for N=3. Some relevant extensions are also analyzed. copyright 1996 The American Physical Society
Phase transition in a spatial Lotka-Volterra model
International Nuclear Information System (INIS)
Szabo, Gyorgy; Czaran, Tamas
2001-01-01
Spatial evolution is investigated in a simulated system of nine competing and mutating bacterium strains, which mimics the biochemical war among bacteria capable of producing two different bacteriocins (toxins) at most. Random sequential dynamics on a square lattice is governed by very symmetrical transition rules for neighborhood invasions of sensitive strains by killers, killers by resistants, and resistants by sensitives. The community of the nine possible toxicity/resistance types undergoes a critical phase transition as the uniform transmutation rates between the types decreases below a critical value P c above that all the nine types of strains coexist with equal frequencies. Passing the critical mutation rate from above, the system collapses into one of three topologically identical (degenerated) states, each consisting of three strain types. Of the three possible final states each accrues with equal probability and all three maintain themselves in a self-organizing polydomain structure via cyclic invasions. Our Monte Carlo simulations support that this symmetry-breaking transition belongs to the universality class of the three-state Potts model
Linearizability conditions for Lotka-Volterra planar complex cubic systems
International Nuclear Information System (INIS)
Gine, Jaume; Romanovski, Valery G
2009-01-01
In this paper, we investigate the linearizability problem for the two-dimensional planar complex system x-dot=x(1-a 10 x-a 01 y-a 20 x 2 -a 11 xy-a 02 y 2 ), y-dot=(1-b 10 x-b 01 y-b 20 x 2 -b 11 xy-b 02 y 2 ). The necessary and sufficient conditions for the linearizability of this system are found. From them the conditions for isochronicity of the corresponding real system can be derived
Grid Integration Research | Wind | NREL
Grid Integration Research Grid Integration Research Researchers study grid integration of wind three wind turbines with transmission lines in the background. Capabilities NREL's grid integration electric power system operators to more efficiently manage wind grid system integration. A photo of
Distribution Integration | Grid Modernization | NREL
Distribution Integration Distribution Integration The goal of NREL's distribution integration research is to tackle the challenges facing the widespread integration of distributed energy resources NREL engineers mapping out a grid model on a whiteboard. NREL's research on the integration of
Transmission Integration | Grid Modernization | NREL
Transmission Integration Transmission Integration The goal of NREL's transmission integration integration issues and provide data, analysis, and models to enable the electric power system to more and finding solutions to address them to enable transmission grid integration. Capabilities Power
International Nuclear Information System (INIS)
Sun Yi; Chang Haoran
2012-01-01
By further examining the symmetry of external momenta and masses in Feynman integrals, we fulfilled the method proposed by Battistel and Dallabona, and showed that recursion relations in this method can be applied to simplify Feynman integrals directly. (authors)
Laplace Transforms without Integration
Robertson, Robert L.
2017-01-01
Calculating Laplace transforms from the definition often requires tedious integrations. This paper provides an integration-free technique for calculating Laplace transforms of many familiar functions. It also shows how the technique can be applied to probability theory.
Sesquilinear uniform vector integral
Indian Academy of Sciences (India)
theory, together with his integral, dominate contemporary mathematics. ... directions belonging to Bartle and Dinculeanu (see [1], [6], [7] and [2]). ... in this manner, namely he integrated vector functions with respect to measures of bounded.
The Integrated Renovation Process
DEFF Research Database (Denmark)
Galiotto, Nicolas; Heiselberg, Per; Knudstrup, Mary-Ann
The Integrated Renovation Process (IRP) is a user customized methodology based on judiciously selected constructivist and interactive multi-criteria decision making methods (Galiotto, Heiselberg, & Knudstrup, 2014 (expected)). When applied for home renovation, the Integrated Renovation Process...
Pandey, Chandan
2015-01-01
This book is intended for developers who are either already involved with enterprise integration or planning to venture into the domain. Basic knowledge of Java and Spring is expected. For newer users, this book can be used to understand an integration scenario, what the challenges are, and how Spring Integration can be used to solve it. Prior experience of Spring Integration is not expected as this book will walk you through all the code examples.
Tucker, Jerry H.; Tapia, Moiez A.; Bennett, A. Wayne
1988-01-01
The concept of Boolean integration is developed, and different Boolean integral operators are introduced. Given the changes in a desired function in terms of the changes in its arguments, the ways of 'integrating' (i.e. realizing) such a function, if it exists, are presented. The necessary and sufficient conditions for integrating, in different senses, the expression specifying the changes are obtained. Boolean calculus has applications in the design of logic circuits and in fault analysis.
Integrated vs. Federated Search
DEFF Research Database (Denmark)
Løvschall, Kasper
2009-01-01
Oplæg om forskelle og ligheder mellem integrated og federated search i bibliotekskontekst. Holdt ved temadag om "Integrated Search - samsøgning i alle kilder" på Danmarks Biblioteksskole den 22. januar 2009.......Oplæg om forskelle og ligheder mellem integrated og federated search i bibliotekskontekst. Holdt ved temadag om "Integrated Search - samsøgning i alle kilder" på Danmarks Biblioteksskole den 22. januar 2009....
Integrated nursery pest management
R. Kasten Dumroese
2012-01-01
What is integrated pest management? Take a look at the definition of each word to better understand the concept. Two of the words (integrated and management) are relatively straightforward. Integrated means to blend pieces or concepts into a unified whole, and management is the wise use of techniques to successfully accomplish a desired outcome. A pest is any biotic (...
Ahner, Henry
2009-01-01
Integration (here visualized as a pounding process) is mathematically realized by simple transformations, successively smoothing the bounding curve into a straight line and the region-to-be-integrated into an area-equivalent rectangle. The relationship to Riemann sums, and to the trapezoid and midpoint methods of numerical integration, is…
Discrete bipolar universal integrals
Czech Academy of Sciences Publication Activity Database
Greco, S.; Mesiar, Radko; Rindone, F.
2014-01-01
Roč. 252, č. 1 (2014), s. 55-65 ISSN 0165-0114 R&D Projects: GA ČR GAP402/11/0378 Institutional support: RVO:67985556 Keywords : bipolar integral * universal integral * Choquet integral Subject RIV: BA - General Mathematics Impact factor: 1.986, year: 2014 http://library.utia.cas.cz/separaty/2014/E/mesiar-0432224.pdf
Responsibility and Integrated Thinking
Robinson, SJ
2014-01-01
Integrated thinking is essentially focused in dialogue and communication. This is partly because relationships and related purpose focus on action, which itself acts as a means of integration, and partly because critical dialogue enables better, more responsive, integrated thinking and action.
Moerel, J.L.; Halswijk, W.
2010-01-01
These notes deal with the integration of a (sc)ramjet engine in either an axisymmetric or a waverider type of cruise missile configuration. The integration aspects relate to the integration of the external and internal flow paths in geometrical configurations that are being considered worldwide.
Foundations for Psychotherapy Integration
Directory of Open Access Journals (Sweden)
António Branco Vasco
2014-10-01
Full Text Available The movement for integration in psychotheray is clearly one of the main trends that can be observed in the field. The author stresses three main reasons for this state of affairs and as a way of justifying the importance of integration: historical and psychosocial, empirical and philosophical. A specific way of thinking in integrative terms is also outlined - "paradigmatic complementarity."
Steffensen's integral inequality for conformable fractional integrals
Directory of Open Access Journals (Sweden)
Mehmet Zeki Sarikaya
2017-09-01
Full Text Available The aim of this paper is to establish some Steffensen’s type inequalities for conformable fractional integral. The results presented here would provide generalizations of those given in earlier works.
International Nuclear Information System (INIS)
Juanarena, D.B.; Rao, M.G.
1991-01-01
Integrated cryogenic pressure-temperature, level-temperature, and flow-temperature sensors have several advantages over the conventional single parameter sensors. Such integrated sensors were not available until recently. Pressure Systems, Inc. (PSI) of Hampton, Virginia, has introduced precalibrated precision cryogenic pressure sensors at the Los Angeles Cryogenic Engineering Conference in 1989. Recently, PSI has successfully completed the development of integrated pressure-temperature and level-temperature sensors for use in the temperature range 1.5-375K. In this paper, performance characteristics of these integrated sensors are presented. Further, the effects of irradiation and magnetic fields on these integrated sensors are also reviewed
DEFF Research Database (Denmark)
Pitkänen, Kati; Oratuomi, Joose; Hellgren, Daniela
Increased attention to, and careful planning of the integration of migrants into Nordic societies is ever more important. Nature based integration is a new solution to respond to this need. This report presents the results of a Nordic survey and workshop and illustrates current practices of nature...... based integration by case study descriptions from Denmark, Sweden Norway and Finland. Across Nordic countries several practical projects and initiatives have been launched to promote the benefits of nature in integration and there is also growing academic interest in the topic. Nordic countries have...... the potential of becoming real forerunners in nature based integration even at the global scale....
Krainak, Michael; Merritt, Scott
2016-01-01
Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.
International Nuclear Information System (INIS)
Thatcher, D.
1989-01-01
The NRC has recognized the need to integrate generic issues (GIs). The GI process includes a number of phases, all of which should recognize the potential for overlap and conflict among related issues. In addition to the issues themselves, other related NRC and industry programs and activities need to be factored into the GI process. Integration has taken place, or is taking place, for a number of GIs. Each case of integration involves a specific set of circumstances and, as a result, the way in which integration proceeds can vary. This paper discusses the integration of issues in the generic issue process and provides a number of examples
DEFF Research Database (Denmark)
Bygstad, Bendik; Nielsen, Peter Axel; Munkvold, Bjørn Erik
2010-01-01
This paper aims to contribute to a theory of integration within the field of IS project management. Integration is a key IS project management issue when new systems are developed and implemented into an increasingly integrated information infrastructure in corporate and governmental organizations....... Expanding the perspective of traditional project management research, we draw extensively on central insights from IS research. Building on socio-technical IS research and Software Engineering research we suggest four generic patterns of integration: Big Bang, Stakeholder Integration, Technical Integration...... and Socio-Technical Integration. We analyze and describe the advantages and disadvantages of each pattern. The four patterns are ideal types. To explore the forces and challenges in these patterns three longitudinal case studies were conducted. In particular we investigate the management challenges for each...
Searching for integrable systems
International Nuclear Information System (INIS)
Cary, J.R.
1984-01-01
Lack of integrability leads to undesirable consequences in a number of physical systems. The lack of integrability of the magnetic field leads to enhanced particle transport in stellarators and tokamaks with tearing-mode turbulence. Limitations of the luminosity of colliding beams may be due to the onset of stochasticity. Enhanced radial transport in mirror machines caused by the lack of integrability and/or the presence of resonances may be a significant problem in future devices. To improve such systems one needs a systematic method for finding integrable systems. Of course, it is easy to find integrable systems if no restrictions are imposed; textbooks are full of such examples. The problem is to find integrable systems given a set of constraints. An example of this type of problem is that of finding integrable vacuum magnetic fields with rotational transform. The solution to this problem is relevant to the magnetic-confinement program
Energy Systems Integration Facility Videos | Energy Systems Integration
Facility | NREL Energy Systems Integration Facility Videos Energy Systems Integration Facility Integration Facility NREL + SolarCity: Maximizing Solar Power on Electrical Grids Redefining What's Possible for Renewable Energy: Grid Integration Robot-Powered Reliability Testing at NREL's ESIF Microgrid
Energy Systems Integration Laboratory | Energy Systems Integration Facility
| NREL Integration Laboratory Energy Systems Integration Laboratory Research in the Energy Systems Integration Laboratory is advancing engineering knowledge and market deployment of hydrogen technologies. Applications include microgrids, energy storage for renewables integration, and home- and station
Hinkel, J.
2008-01-01
Keywords: climate change, integrated assessment, knowledge integration, transdisciplinary research, vulnerability, vulnerability assessment.
This thesis explores how transdisciplinary knowledge integration can be facilitated in the context of integrated assessments and vulnerability
Immigrant Integration: Acculturation and Social Integration
Directory of Open Access Journals (Sweden)
Astrid HAMBERGER
2009-11-01
Full Text Available This article tackles the concept of “immigrant integration” as it is analyzed by different authors in the international migration field. In this article, I will use the terms “refugee” and “immigrant” as equivalent to each other due to the interchangeable character of these concepts throughout the integration literature. First, the article brings into discussion the definitional and conceptual battle around the concept of immigrant “integration”, and second, it will describe and analyze cultural and social integration with their presupposing processes.
What constitutes information integrity?
Directory of Open Access Journals (Sweden)
S. Flowerday
2008-01-01
Full Text Available This research focused on what constitutes information integrity as this is a problem facing companies today. Moreover, information integrity is a pillar of information security and is required in order to have a sound security management programme. However, it is acknowledged that 100% information integrity is not currently achievable due to various limitations and therefore the auditing concept of reasonable assurance is adopted. This is in line with the concept that 100% information security is not achievable and the notion that adequate security is the goal, using appropriate countermeasures. The main contribution of this article is to illustrate the importance of and provide a macro view of what constitutes information integrity. The findings are in harmony with Samuel Johnson's words (1751: 'Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.'
What constitutes information integrity?
Directory of Open Access Journals (Sweden)
S. Flowerday
2007-12-01
Full Text Available This research focused on what constitutes information integrity as this is a problem facing companies today. Moreover, information integrity is a pillar of information security and is required in order to have a sound security management programme. However, it is acknowledged that 100% information integrity is not currently achievable due to various limitations and therefore the auditing concept of reasonable assurance is adopted. This is in line with the concept that 100% information security is not achievable and the notion that adequate security is the goal, using appropriate countermeasures. The main contribution of this article is to illustrate the importance of and provide a macro view of what constitutes information integrity. The findings are in harmony with Samuel Johnson's words (1751: 'Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.'
International Nuclear Information System (INIS)
Golden, L.B.
1968-01-01
In atomic structure calculations, one has to evaluate the Slater integrals. In the present program, the authors evaluate exactly the Slater integral when hydrogenic wave functions are used for the bound-state orbitals. When hydrogenic wave functions are used, the Slater integrals involve integrands which can be written in the form of a product of an exponential, exp(ax) and a known analytic polynomial function, f(x). By repeated partial integration such an integral can be expressed in terms of a finite series involving the exponential, the polynomial function and its derivatives. PL/1-FORMAC has a built-in subroutine that will analytically find the derivatives of any multinomial. Thus, the finite series and hence the Slater integral can be evaluated analytically. (Auth.)
Integrated security system definition
International Nuclear Information System (INIS)
Campbell, G.K.; Hall, J.R. II
1985-01-01
The objectives of an integrated security system are to detect intruders and unauthorized activities with a high degree of reliability and the to deter and delay them until effective response/engagement can be accomplished. Definition of an effective integrated security system requires proper application of a system engineering methodology. This paper summarizes a methodology and describes its application to the problem of integrated security system definition. This process includes requirements identification and analysis, allocation of identified system requirements to the subsystem level and provides a basis for identification of synergistic subsystem elements and for synthesis into an integrated system. The paper discusses how this is accomplished, emphasizing at each step how system integration and subsystem synergism is considered. The paper concludes with the product of the process: implementation of an integrated security system
Bugdol, Marek
2015-01-01
Examining the challenges of integrated management, this book explores the importance and potential benefits of using an integrated approach as a cross-functional concept of management. It covers not only standardized management systems (e.g. International Organization for Standardization), but also models of self-assessment, as well as different types of integration. Furthermore, it demonstrates how processes and systems can be integrated, and how management efficiency can be increased. The major part of this book focuses on management concepts which use integration as a key tool of management processes (e.g. the systematic approach, supply chain management, virtual and network organizations, processes management and total quality management). Case studies, illustrations, and tables are also provided to exemplify and illuminate the content, as well as examples of successful and failed integrations. Providing a particularly useful resource to managers and specialists involved in the improvement of organization...
Integration of reusable systems
Rubin, Stuart
2014-01-01
Software reuse and integration has been described as the process of creating software systems from existing software rather than building software systems from scratch. Whereas reuse solely deals with the artifacts creation, integration focuses on how reusable artifacts interact with the already existing parts of the specified transformation. Currently, most reuse research focuses on creating and integrating adaptable components at development or at compile time. However, with the emergence of ubiquitous computing, reuse technologies that can support adaptation and reconfiguration of architectures and components at runtime are in demand. This edited book includes 15 high quality research papers written by experts in information reuse and integration to cover the most recent advances in the field. These papers are extended versions of the best papers which were presented at IEEE International Conference on Information Reuse and Integration and IEEE International Workshop on Formal Methods Integration, which wa...
Energy Technology Data Exchange (ETDEWEB)
Glasser, M L, E-mail: laryg@clarkson.edu [Department of Physics, Clarkson University, Potsdam, NY 13699-5820 (United States); Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, Valladolid 470071 (Spain)
2011-06-03
The identity {integral}{sub 0}{sup {pi}/2}d{Phi}{integral}{sub 0}{sup {pi}/2}d{Theta} sin{Phi} F(x sn{Phi} sin{Phi})={pi}/2 {integral}{sub 0}{sup 1}F(xt)dt, where F is any function, is derived. Several extensions are given and a few examples of physical interest are described.
International Nuclear Information System (INIS)
Kauffman, L.H.
1990-01-01
This paper gives a heuristic derivation of the skein relation for the Homfly polynomial in an integral formalism. The derivation is formally correct but highly simplified. In the light of Witten's proposal for invariants of links via functional integrals, it is useful to have a formal pattern to compare with the complexities of the full approach. The formalism is a heuristic. However, it is closely related to the actual structure of the Witten functional integral
HETEROGENEOUS INTEGRATION TECHNOLOGY
2017-08-24
AFRL-RY-WP-TR-2017-0168 HETEROGENEOUS INTEGRATION TECHNOLOGY Dr. Burhan Bayraktaroglu Devices for Sensing Branch Aerospace Components & Subsystems...Final September 1, 2016 – May 1, 2017 4. TITLE AND SUBTITLE HETEROGENEOUS INTEGRATION TECHNOLOGY 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER N/A...provide a structure for this review. The history and the current status of integration technologies in each category are examined and product examples are
Branching trajectory continual integral
International Nuclear Information System (INIS)
Maslov, V.P.; Chebotarev, A.M.
1980-01-01
Heuristic definition of the Feynman continual integral over branching trajectories is suggested which makes it possible to obtain in the closed form the solution of the Cauchy problem for the model Hartree equation. A number of properties of the solution is derived from an integral representation. In particular, the quasiclassical asymptotics, exact solution in the gaussian case and perturbation theory series are described. The existence theorem for the simpliest continual integral over branching trajectories is proved [ru
International Nuclear Information System (INIS)
Gautier, G.M.
2002-01-01
This document presents the integrated reactors concepts by a presentation of four reactors: PIUS, SIR, IRIS and CAREM. The core conception, the operating, the safety, the economical aspects and the possible users are detailed. From the performance of the classical integrated PWR, the necessity of new innovative fuels utilization, the research of a simplified design to make easier the safety and the KWh cost decrease, a new integrated reactor is presented: SCAR 600. (A.L.B.)
Classical Mechanics and Symplectic Integration
DEFF Research Database (Denmark)
Nordkvist, Nikolaj; Hjorth, Poul G.
2005-01-01
Content: Classical mechanics: Calculus of variations, Lagrange’s equations, Symmetries and Noether’s theorem, Hamilton’s equations, cannonical transformations, integrable systems, pertubation theory. Symplectic integration: Numerical integrators, symplectic integrators, main theorem on symplectic...
Avionics systems integration technology
Stech, George; Williams, James R.
1988-01-01
A very dramatic and continuing explosion in digital electronics technology has been taking place in the last decade. The prudent and timely application of this technology will provide Army aviation the capability to prevail against a numerically superior enemy threat. The Army and NASA have exploited this technology explosion in the development and application of avionics systems integration technology for new and future aviation systems. A few selected Army avionics integration technology base efforts are discussed. Also discussed is the Avionics Integration Research Laboratory (AIRLAB) that NASA has established at Langley for research into the integration and validation of avionics systems, and evaluation of advanced technology in a total systems context.
Towards THz integrated photonics
Hübers, Heinz-Wilhelm
2010-01-01
The demonstration of an integrated terahertz transceiver featuring a quantum cascade laser and a Schottky diode mixer promises new applications for compact and convenient terahertz photonic instrumentation.
Extending Database Integration Technology
National Research Council Canada - National Science Library
Buneman, Peter
1999-01-01
Formal approaches to the semantics of databases and database languages can have immediate and practical consequences in extending database integration technologies to include a vastly greater range...
Modularly Integrated MEMS Technology
National Research Council Canada - National Science Library
Eyoum, Marie-Angie N
2006-01-01
Process design, development and integration to fabricate reliable MEMS devices on top of VLSI-CMOS electronics without damaging the underlying circuitry have been investigated throughout this dissertation...
Integrated Information Management (IIM)
National Research Council Canada - National Science Library
McIlvain, Jason
2007-01-01
Information Technology is the core capability required to align our resources and increase our effectiveness on the battlefield by integrating and coordinating our preventative measures and responses...
Building integrated photovoltaic; Photovaltaique integre aux batiments
Energy Technology Data Exchange (ETDEWEB)
NONE
2004-01-01
Durable, modular and flexible in use, as demonstrated by the different case studies in this publication, photovoltaic can replace diverse building elements, from glass facades to weather proof roofs. This leaflet towards architects describes aesthetic, technical, economic and environmental interest of building integrated photovoltaic. (author)
Simplification of integrity constraints for data integration
DEFF Research Database (Denmark)
Christiansen, Henning; Martinenghi, Davide
2004-01-01
, because either the global database is known to be consistent or suitable actions have been taken to provide consistent views. The present work generalizes simplification techniques for integrity checking in traditional databases to the combined case. Knowledge of local consistency is employed, perhaps...
Feynman integrals and hyperlogarithms
Energy Technology Data Exchange (ETDEWEB)
Panzer, Erik
2015-02-05
We study Feynman integrals in the representation with Schwinger parameters and derive recursive integral formulas for massless 3- and 4-point functions. Properties of analytic (including dimensional) regularization are summarized and we prove that in the Euclidean region, each Feynman integral can be written as a linear combination of convergent Feynman integrals. This means that one can choose a basis of convergent master integrals and need not evaluate any divergent Feynman graph directly. Secondly we give a self-contained account of hyperlogarithms and explain in detail the algorithms needed for their application to the evaluation of multivariate integrals. We define a new method to track singularities of such integrals and present a computer program that implements the integration method. As our main result, we prove the existence of infinite families of massless 3- and 4-point graphs (including the ladder box graphs with arbitrary loop number and their minors) whose Feynman integrals can be expressed in terms of multiple polylogarithms, to all orders in the ε-expansion. These integrals can be computed effectively with the presented program. We include interesting examples of explicit results for Feynman integrals with up to 6 loops. In particular we present the first exactly computed counterterm in massless φ{sup 4} theory which is not a multiple zeta value, but a linear combination of multiple polylogarithms at primitive sixth roots of unity (and divided by the √(3)). To this end we derive a parity result on the reducibility of the real- and imaginary parts of such numbers into products and terms of lower depth.
Feynman integrals and hyperlogarithms
International Nuclear Information System (INIS)
Panzer, Erik
2015-01-01
We study Feynman integrals in the representation with Schwinger parameters and derive recursive integral formulas for massless 3- and 4-point functions. Properties of analytic (including dimensional) regularization are summarized and we prove that in the Euclidean region, each Feynman integral can be written as a linear combination of convergent Feynman integrals. This means that one can choose a basis of convergent master integrals and need not evaluate any divergent Feynman graph directly. Secondly we give a self-contained account of hyperlogarithms and explain in detail the algorithms needed for their application to the evaluation of multivariate integrals. We define a new method to track singularities of such integrals and present a computer program that implements the integration method. As our main result, we prove the existence of infinite families of massless 3- and 4-point graphs (including the ladder box graphs with arbitrary loop number and their minors) whose Feynman integrals can be expressed in terms of multiple polylogarithms, to all orders in the ε-expansion. These integrals can be computed effectively with the presented program. We include interesting examples of explicit results for Feynman integrals with up to 6 loops. In particular we present the first exactly computed counterterm in massless φ 4 theory which is not a multiple zeta value, but a linear combination of multiple polylogarithms at primitive sixth roots of unity (and divided by the √(3)). To this end we derive a parity result on the reducibility of the real- and imaginary parts of such numbers into products and terms of lower depth.
Factorization of Behavioral Integrity
DEFF Research Database (Denmark)
Li, Ximeng; Nielson, Flemming; Nielson, Hanne Riis
2015-01-01
We develop a bisimulation-based nonintereference property that describes the allowed dependencies between communication behaviors of different integrity levels. The property is able to capture all possible combinations of integrity levels for the “presence” and “content” of actual communications...
Directory of Open Access Journals (Sweden)
D. Naylor
1986-01-01
Full Text Available This paper establishes properties of a convolution type integral transform whose kernel is a Macdonald type Bessel function of zero order. An inversion formula is developed and the transform is applied to obtain the solution of some related integral equations.
Integrated Marketing Communications
Black, Jim
2004-01-01
Integration has become a cliche in enrollment management and student services circles. The term is used to describe everything from integrated marketing to seamless services. Often, it defines organizational structures, processes, student information systems, and even communities. In Robert Sevier's article in this issue of "College and…
Integrated Optical Circuit Engineering
Sriram, S.
1985-04-01
Implementation of single-mode optical fiber systems depends largely on the availability of integrated optical components for such functions as switching, multiplexing, and modulation. The technology of integrated optics is maturing very rapidly, and its growth justifies the optimism that now exists in the optical community.
Czech Academy of Sciences Publication Activity Database
Mesiar, Radko
2005-01-01
Roč. 28, č. 156 (2005), s. 365-370 ISSN 0165-0114 R&D Projects: GA ČR(CZ) GA402/04/1026 Institutional research plan: CEZ:AV0Z10750506 Keywords : fuzzy measures * fuzzy integral * regular fuzzy integral Subject RIV: BA - General Mathematics Impact factor: 1.039, year: 2005
International Nuclear Information System (INIS)
Prokhorov, L.V.
1982-01-01
The properties of path integrals associated with the allowance for nonstandard terms reflecting the operator nature of the canonical variables are considered. Rules for treating such terms (''equivalence rules'') are formulated. Problems with a boundary, the behavior of path integrals under canonical transformations, and the problem of quantization of dynamical systems with constraints are considered in the framework of the method
Ethnic Minorities and Integration
Mérove Gijsberts
2005-01-01
There has been a great deal of discussion in the Netherlands recently about the integration of ethnic minorities. The tenor of that discussion is sombre: some observers speak of a 'multicultural drama', while others claim that the government's integration policy has failed completely. Recent
Backtracking Incremental Continuous Integration
T. van der Storm (Tijs); K. Kontogiannis (Kostas); C. Tjortjis; A. Winter
2008-01-01
htmlabstractFailing integration builds are show stoppers. Development activity is stalled because developers have to wait with integrating new changes until the problem is fixed and a successful build has been run. We show how backtracking can be used to mitigate the impact of build failures in the
International Nuclear Information System (INIS)
Chang, Y.I.; Marchaterre, J.F.; Sevy, R.H.
1984-01-01
Key features of the IFR consist of a pool-type plant arrangement, a metal fuel-based core design, and an integral fuel cycle with colocated fuel cycle facility. Both the basic concept and the technology base have been demonstrated through actual integral cycle operation in EBR-II. This paper discusses the inherent safety characteristics of the IFR concept
DEFF Research Database (Denmark)
Holst, Finn
2010-01-01
Evaluering af projektet Musik, Sprog og Integration, Søndermarkskolen, Horsens. Andenårsevaluering af et treårigt projekt.......Evaluering af projektet Musik, Sprog og Integration, Søndermarkskolen, Horsens. Andenårsevaluering af et treårigt projekt....
Kanonisk sikkerhed og integration
DEFF Research Database (Denmark)
Larsen, Vibe; Øland, Trine
2006-01-01
Artiklen diskuterer, med indragelse af den lignende debat i andre europæiske lande, kulturkanonen i forhold til integration......Artiklen diskuterer, med indragelse af den lignende debat i andre europæiske lande, kulturkanonen i forhold til integration...
DEFF Research Database (Denmark)
Rendtorff, Jacob Dahl
2015-01-01
Integrity can be defined in the following sense: Integrity accounts for the inviolability of the human being. Although originally a virtue of uncorrupted character, expressing uprightness, honesty, and good intentions, it has, like dignity, been universalized as a quality of the person as such...
Integral transformational coaching
Keizer, W.A.J.; Nandram, S.S.
2009-01-01
In Chap. 12, Keizer and Nandram present the concept of Integral Transformational Coaching based on the concept of Flow and its effects on work performance. Integral Transformational Coaching is a method that prevents and cures unhealthy stress and burnout. They draw on some tried and tested
DEFF Research Database (Denmark)
Fogelman, Tatiana
Over the past fifteen years the district of Berlin-Marzahn became home to the largest concentration of post-Soviet migrants of German ancestry in the former East Germany. Drawing on my research in the district, including two of its integration projects for middle-aged, unemployed migrants, I...... examine these projects’ failed attempts to create spaces of encounter between the migrants and district’s long-term residents. In this presentation I focus specifically on the structural position of integration work (Integrationsarbeit) that creates first and foremost conditions of possibility for its...... temporal imaginaries underpinning the ideas of integration through encounter, as well as integration more broadly, I argue for reflexivity-centric public reformulations of both integration and encounter....
Retroviral integration: Site matters
Demeulemeester, Jonas; De Rijck, Jan
2015-01-01
Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co‐opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine‐grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success. PMID:26293289
Neuroeconomics and Integrated Care
DEFF Research Database (Denmark)
Larsen, Torben
2012-01-01
Background: Fragmented specialized care for the frail elderly as claimed by WHO needs horizontal integration across settings. The home of the patient seems to be a promising place to integrate hospital care, primary care and social services for high-risk discharges where the quality...... of rehabilitation makes a difference. Objective: The study aims to reveal how integrated home care may be organised to improve quality of care as compared to usual hospital care. Method: A qualitative case study of the use of a neuroeconomic model in relation to multidisciplianry collaboration on a RCT...... of integrated home care for stroke patients. Results: (1) The classical understanding of CNS is that of a dual system of ANS and Cortex. The new neuroeconomic understanding is that of a reciprocal balance of Limbic System (LS) and Neocortex (NC). This applies directly in favour of integrated homecare compared...
International Nuclear Information System (INIS)
Hira, Anil; Amaya, Libardo
2003-01-01
Amidst the international movement to privatize and deregulate electricity and gas sectors of economies, the question of the integration of those sectors has been somewhat underestimated. In fact, the integration of energy markets across boundaries is occurring. We examine this process in three regions: Europe, Central America, and South America. We analyze the forces driving integration in each area, and estimate the prospects for progress. We take a close look at Nordpool, which is now the most integrated market in the world, to see if it can serve as a model for other regions. We close with a set of conditions that we suggest are necessary for a successful international integration of energy markets
International Nuclear Information System (INIS)
Hira, A.; Amaya, L.
2003-01-01
Amidst the international movement to privatize and deregulate electricity and gas sectors of economics, the question of the integration of those sectors has been somewhat underestimated. In fact, the integration of energy markets across boundaries is occurring. We examine this process in three regions: Europe, Central America, and South America. We analyze the forces driving integration in each area, and estimate the prospects for progress. We take a close look at Nordpool, which is now the most integrated market in the world, to see if it can serve as a model for other regions. We close with a set of conditions that we suggest are necessary for a successful international integration of energy markets. (author)
International Nuclear Information System (INIS)
Henry, R.; Sumpter, K.C.
1995-01-01
In 1992, the Secretary of Energy directed the Assistant Secretary for Environmental Management (EM) to develop an integrated, long-term, spent nuclear fuel (SNF) management program. In response, EM created the Integrated SNF Program to assess the US Department of Energy (DOE) SNF and SNF storage facilities. As shown in Figure 1 the Integrated SNF Program is responsible for life-cycle management of DOE SNF; that is characterization, processing, interim storage and preparation for disposal. In order to implement the Program it was recognized that technology needs must be identified. A Technology Integration Program was formed to integrate the DOE complex-wide efforts for establishing timely, cost effective and consistent technical criteria for the development of technical solutions. The program is directed toward identification of: (a) what activities need to be done, (b) when they need to be completed, and (c) what priority should be assigned to the various activities
Integrated silicon optoelectronics
Zimmermann, Horst
2000-01-01
'Integrated Silicon Optoelectronics'assembles optoelectronics and microelectronics The book concentrates on silicon as the major basis of modern semiconductor devices and circuits Starting from the basics of optical emission and absorption and from the device physics of photodetectors, the aspects of the integration of photodetectors in modern bipolar, CMOS, and BiCMOS technologies are discussed Detailed descriptions of fabrication technologies and applications of optoelectronic integrated circuits are included The book, furthermore, contains a review of the state of research on eagerly expected silicon light emitters In order to cover the topic of the book comprehensively, integrated waveguides, gratings, and optoelectronic power devices are included in addition Numerous elaborate illustrations promote an easy comprehension 'Integrated Silicon Optoelectronics'will be of value to engineers, physicists, and scientists in industry and at universities The book is also recommendable for graduate students speciali...
Smirnov, Vladimir A
2006-01-01
The problem of evaluating Feynman integrals over loop momenta has existed from the early days of perturbative quantum field theory. The goal of the book is to summarize those methods for evaluating Feynman integrals that have been developed over a span of more than fifty years. `Feynman Integral Calculus' characterizes the most powerful methods in a systematic way. It concentrates on the methods that have been employed recently for most sophisticated calculations and illustrates them with numerous examples, starting from very simple ones and progressing to nontrivial examples. It also shows how to choose adequate methods and combine them in a non-trivial way. This is a textbook version of the previous book (Evaluating Feynman integrals, STMP 211) of the author. Problems and solutions have been included, Appendix G has been added, more details have been presented, recent publications on evaluating Feynman integrals have been taken into account and the bibliography has been updated.
Personal Integrity and Leadership
Directory of Open Access Journals (Sweden)
Antonius Gea
2016-07-01
Full Text Available Generally, integrity is associated with leadership, especially in the organization or company. Integrity in leadership becomes a growing concern in business and organizations. The aim of this study was to find out the connection that could be shaped between personal integrity and the skill of leadership especially in the performance of work. This study used a library research, a literature study that done by using the available resources and relevant literature, related to the topic being discussed by the author. Books or journal articles related to topics were used as background reading to understand well about the problems of integrity and leadership, especially in the organization or company. This study finds out that the leader integrity is related to follower work role performance and that this effect is fully mediated through follower affective organizational commitment.
Vertcal integration: origins of oil industry integration
International Nuclear Information System (INIS)
Rainbow, R.
2001-01-01
This article examines the structure of the US oil industry in relation to the history of the industry, capital market assumptions, and advice on the enhancement of 'shareholder value'. The driving forces behind the attempts to establish cartels and vertical integration are considered, and the emergence of US companies resulting from the break-up of the Standard Oil Trust cartel, the influence of costs and logistics on the structure of the industry outside the USA , and the structure of the natural gas industry are discussed along with the discovery of large Middle East oil reserves, the enormous growth in demand for oil products in Europe and Japan, and the formation of the OPEC cartel. Details are given of the breaking down of vertical integration in the big oil companies, the theory of conglomerates, the success of big companies, the importance of scale to balance exploration risks, and the need to adjust in time to shifts in the business environment
Long Pulse Integrator of Variable Integral Time Constant
International Nuclear Information System (INIS)
Wang Yong; Ji Zhenshan; Du Xiaoying; Wu Yichun; Li Shi; Luo Jiarong
2010-01-01
A kind of new long pulse integrator was designed based on the method of variable integral time constant and deducting integral drift by drift slope. The integral time constant can be changed by choosing different integral resistors, in order to improve the signal-to-noise ratio, and avoid output saturation; the slope of integral drift of a certain period of time can be calculated by digital signal processing, which can be used to deduct the drift of original integral signal in real time to reduce the integral drift. The tests show that this kind of long pulse integrator is good at reducing integral drift, which also can eliminate the effects of changing integral time constant. According to experiments, the integral time constant can be changed by remote control and manual adjustment of integral drift is avoided, which can improve the experiment efficiency greatly and can be used for electromagnetic measurement in Tokamak experiment. (authors)
Energy Technology Data Exchange (ETDEWEB)
NONE
1995-04-01
Integrated assessment can be used to evaluate and clarify resource management policy options and outcomes for decision makers. The defining characteristics of integrated assessment are (1) focus on providing information and analysis that can be understood and used by decision makers rather than for merely advancing understanding and (2) its multidisciplinary approach, using methods, styles of study, and considerations from a broader variety of technical areas than would typically characterize studies produced from a single disciplinary standpoint. Integrated assessment may combine scientific, social, economic, health, and environmental data and models. Integrated assessment requires bridging the gap between science and policy considerations. Because not everything can be valued using a single metric, such as a dollar value, the integrated assessment process also involves evaluating trade-offs among dissimilar attributes. Scientists at Oak Ridge National Laboratory (ORNL) recognized the importance and value of multidisciplinary approaches to solving environmental problems early on and have pioneered the development of tools and methods for integrated assessment over the past three decades. Major examples of ORNL`s experience in the development of its capabilities for integrated assessment are given.
Measure and integration theory
Burckel, Robert B
2001-01-01
This book gives a straightforward introduction to the field as it is nowadays required in many branches of analysis and especially in probability theory. The first three chapters (Measure Theory, Integration Theory, Product Measures) basically follow the clear and approved exposition given in the author's earlier book on ""Probability Theory and Measure Theory"". Special emphasis is laid on a complete discussion of the transformation of measures and integration with respect to the product measure, convergence theorems, parameter depending integrals, as well as the Radon-Nikodym theorem. The fi
International Nuclear Information System (INIS)
DeWitt-Morette, C.
1983-01-01
Much is expected of path integration as a quantization procedure. Much more is possible if one recognizes that path integration is at the crossroad of stochastic and differential calculus and uses the full power of both stochastic and differential calculus in setting up and computing path integrals. In contrast to differential calculus, stochastic calculus has only comparatively recently become an instrument of thought. It has nevertheless already been used in a variety of challenging problems, for instance in the quantization problem. The author presents some applications of the stochastic scheme. (Auth.)
SQL Server Integration Services
Hamilton, Bill
2007-01-01
SQL Server 2005 Integration Services (SSIS) lets you build high-performance data integration solutions. SSIS solutions wrap sophisticated workflows around tasks that extract, transform, and load (ETL) data from and to a wide variety of data sources. This Short Cut begins with an overview of key SSIS concepts, capabilities, standard workflow and ETL elements, the development environment, execution, deployment, and migration from Data Transformation Services (DTS). Next, you'll see how to apply the concepts you've learned through hands-on examples of common integration scenarios. Once you've
Wolfendale, E
2013-01-01
MOS Integral Circuit Design aims to help in the design of integrated circuits, especially large-scale ones, using MOS Technology through teaching of techniques, practical applications, and examples. The book covers topics such as design equation and process parameters; MOS static and dynamic circuits; logic design techniques, system partitioning, and layout techniques. Also featured are computer aids such as logic simulation and mask layout, as well as examples on simple MOS design. The text is recommended for electrical engineers who would like to know how to use MOS for integral circuit desi
International Nuclear Information System (INIS)
Li Xianyao; Yuan Taonu; Shao Shiqian; Shi Zujun; Wang Yi; Yu Yude; Yu Jinzhong
2011-01-01
Recently,much attention has concentrated on silicon based photonic integrated circuits (PICs), which provide a cost-effective solution for high speed, wide bandwidth optical interconnection and optical communication.To integrate III-V compounds and germanium semiconductors on silicon substrates,at present there are two kinds of manufacturing methods, i.e., heteroepitaxy and bonding. Low-temperature wafer bonding which can overcome the high growth temperature, lattice mismatch,and incompatibility of thermal expansion coefficients during heteroepitaxy, has offered the possibility for large-scale heterogeneous integration. In this paper, several commonly used bonding methods are reviewed, and the future trends of low temperature wafer bonding envisaged. (authors)
Three dimensional system integration
Papanikolaou, Antonis; Radojcic, Riko
2010-01-01
Three-dimensional (3D) integrated circuit (IC) stacking is the next big step in electronic system integration. It enables packing more functionality, as well as integration of heterogeneous materials, devices, and signals, in the same space (volume). This results in consumer electronics (e.g., mobile, handheld devices) which can run more powerful applications, such as full-length movies and 3D games, with longer battery life. This technology is so promising that it is expected to be a mainstream technology a few years from now, less than 10-15 years from its original conception. To achieve thi
Principles of data integration
Doan, AnHai; Ives, Zachary
2012-01-01
How do you approach answering queries when your data is stored in multiple databases that were designed independently by different people? This is first comprehensive book on data integration and is written by three of the most respected experts in the field. This book provides an extensive introduction to the theory and concepts underlying today's data integration techniques, with detailed, instruction for their application using concrete examples throughout to explain the concepts. Data integration is the problem of answering queries that span multiple data sources (e.g., databases, web
The Structural Integrity Centre
International Nuclear Information System (INIS)
Tomkins, B.
1987-01-01
The paper concerns the development and work of the Structural Integrity Centre (SIC) at Risley Nuclear Laboratories, United Kingdom. The centre was set up to provide authoritative advice to plant designers and operators on the integrity and life assessment of structures and components across the reactor projects in the United Kingdom. A description is given of the structure and role of the SIC, as well as the Structural Integrity Assessment work. The assessment methods are described for thermally loaded structures and welded structures. Finally, defect significance assessment and environmental effects are outlined. (U.K.)
Energy Technology Data Exchange (ETDEWEB)
Kelley, C.T.; Xue, Z.Q. [North Carolina State Univ., Raleigh, NC (United States)
1994-12-31
Many discretizations of integral equations and compact fixed point problems are collectively compact and strongly convergent in spaces of continuous functions. These properties not only lead to stable and convergent approximations but also can be used in the construction of fast multilevel algorithms. Recently the GMRES algorithm has become a standard coarse mesh solver. The purpose of this paper is to show how the special properties of integral operators and their approximations are reflected in the performance of the GMRES iteration and how these properties can be used to strengthen the norm in which convergence takes place. The authors illustrate these ideas with composite Gauss rules for integral equations on the unit interval.
Energy Technology Data Exchange (ETDEWEB)
Carey, James W. [Los Alamos National Laboratory; Bachu, Stefan [Alberta Innovates
2012-06-21
In this presentation, we review the current state of knowledge on wellbore integrity as developed in the IEA Greenhouse Gas Programme's Wellbore Integrity Network. Wells are one of the primary risks to the successful implementation of CO{sub 2} storage programs. Experimental studies show that wellbore materials react with CO{sub 2} (carbonation of cement and corrosion of steel) but the impact on zonal isolation is unclear. Field studies of wells in CO{sub 2}-bearing fields show that CO{sub 2} does migrate external to casing. However, rates and amounts of CO{sub 2} have not been quantified. At the decade time scale, wellbore integrity is driven by construction quality and geomechanical processes. Over longer time-scales (> 100 years), chemical processes (cement degradation and corrosion) become more important, but competing geomechanical processes may preserve wellbore integrity.
Integration, measure and probability
Pitt, H R
2012-01-01
Introductory treatment develops the theory of integration in a general context, making it applicable to other branches of analysis. More specialized topics include convergence theorems and random sequences and functions. 1963 edition.
Introduction to integral discriminants
International Nuclear Information System (INIS)
Morozov, A.; Shakirov, Sh.
2009-01-01
The simplest partition function, associated with homogeneous symmetric forms S of degree r in n variables, is integral discriminant J n|r (S) = ∫e -S(x 1 ,...,x n ) dx 1 ...dx n . Actually, S-dependence remains the same if e -S in the integrand is substituted by arbitrary function f(S), i.e. integral discriminant is a characteristic of the form S itself, and not of the averaging procedure. The aim of the present paper is to calculate J n|r in a number of non-Gaussian cases. Using Ward identities - linear differential equations, satisfied by integral discriminants - we calculate J 2|3 ,J 2|4 ,J 2|5 and J 3|3 . In all these examples, integral discriminant appears to be a generalized hypergeometric function. It depends on several SL(n) invariants of S, with essential singularities controlled by the ordinary algebraic discriminant of S.
Entrepreneurial Integration Skills
DEFF Research Database (Denmark)
Bauer, Florian; Schriber, Svante; King, David R.
2016-01-01
on 116 acquisitions, we find that entrepreneurial integration skills can display both advantages and disadvantages. While it helps to realize expected and serendipitous synergies, it can also trigger employee uncertainty due to decreased transparency. In supplementary analysis, we show measures...
Managing for Organizational Integrity.
Paine, Lynn Sharp
1994-01-01
Compliance-based ethics programs focus on prevention, detection, and punishment. Companies should adopt an integrity-based approach to ethics management that combines a concern for the law with an emphasis on managerial responsibility for ethical behavior. (JOW)
Babusci, D.; Dattoli, G.; Germano, B.; Martinelli, M. R.; Ricci, P. E.
2011-01-01
We use the operator method to evaluate a class of integrals involving Bessel or Bessel-type functions. The technique we propose is based on the formal reduction of these family of functions to Gaussians.
Integration, Informationslogistik und Architektur
Turowski, Klaus
2006-01-01
Integration, Informationslogistik und Architektur : DW2006 ; 21./22.09.2006 in Friedrichshafen, Germany / Klaus Turowski ... (Hrsg.). - Bonn : Ges. für Informatik, 2006. - 490 S. - (GI-Edition / Proceedings ; 90)
Integrated inventory information system
Digital Repository Service at National Institute of Oceanography (India)
Sarupria, J.S.; Kunte, P.D.
The nature of oceanographic data and the management of inventory level information are described in Integrated Inventory Information System (IIIS). It is shown how a ROSCOPO (report on observations/samples collected during oceanographic programme...
Integrated Surface Dataset (Global)
National Oceanic and Atmospheric Administration, Department of Commerce — The Integrated Surface (ISD) Dataset (ISD) is composed of worldwide surface weather observations from over 35,000 stations, though the best spatial coverage is...
2016-01-01
The integration of a DNA copy of the viral RNA genome into host chromatin is the defining step of retroviral replication. This enzymatic process is catalyzed by the virus-encoded integrase protein, which is conserved among retroviruses and LTR-retrotransposons. Retroviral integration proceeds via two integrase activities: 3′-processing of the viral DNA ends, followed by the strand transfer of the processed ends into host cell chromosomal DNA. Herein we review the molecular mechanism of retroviral DNA integration, with an emphasis on reaction chemistries and architectures of the nucleoprotein complexes involved. We additionally discuss the latest advances on anti-integrase drug development for the treatment of AIDS and the utility of integrating retroviral vectors in gene therapy applications. PMID:27198982
Integrated Reporting Information System -
Department of Transportation — The Integrated Reporting Information System (IRIS) is a flexible and scalable web-based system that supports post operational analysis and evaluation of the National...
Crisis and Regional Integration
DEFF Research Database (Denmark)
Dosenrode, Søren
, Tunisia, Egypt …. ), where the crisis referred to could be humanitarian, environmental, economic, political … Europe, too, has also according to mass media, been a victim of a crisis, the financial one. Could ‘crisis’ be a beginning of enhanced regional integration? This paper will try to look...... at the processes of regional integration in relation to ‘crisis’ in Africa and Europe. First, this paper will look at the concept of ‘crisis’, before it moves on to discuss ‘regional integration’ and the correlation between the two, emphasizing the approaches of neo-functionalism and federal theory....... This is the basis for two short case studies of African and European regional integration. The paper tentative answers to the question: will the crisis in Africa and Europe respectively further or block regional integration? With a ‘that depends’. But the use of Federalism theory and neo-functionalism is seen...
Huston, James A.
1971-01-01
Recounts the history and problems of European Economic Integration from the first post World War II organization, the OEEC, to the EEC (Common Market) and the EFTA. Suggestions for further reading are included. (JB)
National Research Council Canada - National Science Library
Gilstrap, Jeff
1998-01-01
... (IR) pointer into an advanced weapon sight and surveillance system. The Integrated Sight is being developed as a technology demonstrator and potential future upgrade to the Land Warrior and Thermal Weapon Sight Programs...
Funkhouser, John; Deslich, Barbara J.
2000-01-01
Explains the implementation of forensic science in an integrated curriculum and discusses the advantages of this approach. Lists the forensic science course syllabi studied in three high schools. Discusses the unit on polymers in detail. (YDS)
International Nuclear Information System (INIS)
Itzykson, C.
1992-01-01
Some mathematical results are described on a remarkable application of matrix interaction due to Witten and Kontsevich, to study topological invariants. Some interesting properties of the Kontsevich integrals are identified. (K.A.) 4 refs
Integrated Transdisciplinary Teams.
Gallivan-Fenlon, Amanda
1994-01-01
This article reviews the use of transdisciplinary teaming and integrated therapy for young children with multiple disabilities. It presents examples and suggestions for implementation, in the areas of flexibility, Individualized Education Program development, and parent participation. (JDD)
Lectures on integral transforms
Akhiezer, N I
1988-01-01
This book, which grew out of lectures given over the course of several years at Kharkov University for students in the Faculty of Mechanics and Mathematics, is devoted to classical integral transforms, principally the Fourier transform, and their applications. The author develops the general theory of the Fourier transform for the space L^1(E_n) of integrable functions of n variables. His proof of the inversion theorem is based on the general Bochner theorem on integral transforms, a theorem having other applications within the subject area of the book. The author also covers Fourier-Plancherel theory in L^2(E_n). In addition to the general theory of integral transforms, connections are established with other areas of mathematical analysis--such as the theory of harmonic and analytic functions, the theory of orthogonal polynomials, and the moment problem--as well as to mathematical physics.
Complementary and Integrative Medicine
... medical treatments that are not part of mainstream medicine. When you are using these types of care, it may be called complementary, integrative, or alternative medicine. Complementary medicine is used together with mainstream medical ...
Integration a functional approach
Bichteler, Klaus
1998-01-01
This book covers Lebesgue integration and its generalizations from Daniell's point of view, modified by the use of seminorms. Integrating functions rather than measuring sets is posited as the main purpose of measure theory. From this point of view Lebesgue's integral can be had as a rather straightforward, even simplistic, extension of Riemann's integral; and its aims, definitions, and procedures can be motivated at an elementary level. The notion of measurability, for example, is suggested by Littlewood's observations rather than being conveyed authoritatively through definitions of (sigma)-algebras and good-cut-conditions, the latter of which are hard to justify and thus appear mysterious, even nettlesome, to the beginner. The approach taken provides the additional benefit of cutting the labor in half. The use of seminorms, ubiquitous in modern analysis, speeds things up even further. The book is intended for the reader who has some experience with proofs, a beginning graduate student for example. It might...
Varieties of Cognitive Integration
Scott, William A.
1974-01-01
The author examines how students in three countries use four styles of cognitive integration (affective balance, affective-evaluative consistency, centralization, and image comparability) within the cognitive domains of nations, acquaintances, self-roles, and family relations. (DE)
Chester, A; Bertolotti, M
1994-01-01
This volwne contains the Proceedings of a two-week summer conference titled "Advances in Integrated Optics" held June 1-9, 1993, in Erice, Sicily. This was the 18th annual course organized by the International School of Quantum Electronics, under the auspices of the "Ettore Majorana" Centre for Scientific Culture. The term Integrated Optics signifies guided-wave optical circuits consisting of two or more devices on a single substrate. Since its inception in the late 1960's, Integrated Optics has evolved from a specialized research topic into a broad field of work, ranging from basic research through commercial applications. Today many devices are available on market while a big effort is devolved to research on integrated nonlinear optical devices. This conference was organized to provide a comprehensive survey of the frontiers of this technology, including fundamental concepts, nonlinear optical materials, devices both in the linear and nonlinear regimes, and selected applications. These Proceedings update a...
Integrated Health Management Definitions
National Aeronautics and Space Administration — The Joint Army Navy NASA Air Force Modeling and Simulation Subcommittee's Integrated Health Management panel was started about 6 years ago to help foster...
State Program Integrity Reviews
U.S. Department of Health & Human Services — State program integrity reviews play a critical role in how CMS provides effective support and assistance to states in their efforts to combat provider fraud and...
Systems Integration Fact Sheet
Energy Technology Data Exchange (ETDEWEB)
None
2016-06-01
This fact sheet is an overview of the Systems Integration subprogram at the U.S. Department of Energy SunShot Initiative. The Systems Integration subprogram enables the widespread deployment of safe, reliable, and cost-effective solar energy technologies by addressing the associated technical and non-technical challenges. These include timely and cost-effective interconnection procedures, optimal system planning, accurate prediction of solar resources, monitoring and control of solar power, maintaining grid reliability and stability, and many more. To address the challenges associated with interconnecting and integrating hundreds of gigawatts of solar power onto the electricity grid, the Systems Integration program funds research, development, and demonstration projects in four broad, interrelated focus areas: grid performance and reliability, dispatchability, power electronics, and communications.
Cohn, Hans M.
1983-01-01
Argues that although the executive has many tasks, he or she must view internal organizational integration as a primary task, making use of organizational charts, job descriptions, statements of goals and objectives, evaluations, and feedback devices. (RH)
DEFF Research Database (Denmark)
Strandberg-Larsen, Martin
2011-01-01
respond to these needs, patients and providers face the multiple challenges of today's healthcare environment. Decision makers, planners and managers need evidence based policy options and information on the scope of the integrated care challenges they are facing. The US managed care organization Kaiser...... differences were found in the perception of clinical integration in the two settings. More primary care clinicians in the Northern California region of Kaiser Permanente reported being part of a clinical integrated environment than did Danish general practitioners. By measuring the level of clinical...... and performance of the Danish healthcare system and the managed care organization Kaiser Permanente, California, US. 5) To compare primary care clinicians' perception of clinical integration in two healthcare systems: Kaiser Permanente, Northern California and the Danish healthcare system. Further to examine...
Integrated Criteria Document Chromium
Slooff W; Cleven RFMJ; Janus JA; van der Poel P; van Beelen P; Boumans LJM; Canton JH; Eerens HC; Krajnc EI; de Leeuw FAAM; Matthijsen AJCM; van de Meent D; van der Meulen A; Mohn GR; Wijland GC; de Bruijn PJ; van Keulen A; Verburgh JJ; van der Woerd KF
1990-01-01
Betreft de engelse versie van rapport 758701001
Bij dit rapport behoort een appendix onder hetzelfde nummer getiteld: "Integrated Criteria Document Chromium: Effects" Auteurs: Janus JA; Krajnc EI
(appendix: see 710401002A)
Financial Integrity Benchmarks
City of Jackson, Mississippi — This data compiles standard financial integrity benchmarks that allow the City to measure its financial standing. It measure the City's debt ratio and bond ratings....
Federal Laboratory Consortium — Located near the center of the 586-square-mile Hanford Site is the Integrated Disposal Facility, also known as the IDF.This facility is a landfill similar in concept...
4 pitfalls to clinical integration.
Redding, John
2012-11-01
Four common mistakes can easily thwart clinical integration: Assuming that EHR adoption is the cornerstone of successful integration; Delaying the development of ambulatory services that support clinical integration; Believing that knowledge of clinical integration initiatives will passively diffuse through the ranks; Attaching too much weight to Federal Trade Commission/Department of Justice approval of a clinical integration model.
Heterogeneous Integration Technology
2017-05-19
integrated CMOS imaging system for high frame rate applications [171]. .................... 68 Figure 83: CPU-DRAM Memory Landscape . [127... film transistors (TFT) were integrated with GaN HEMTs on the same wafer at AFRL. The thin film transistor fabrication using metal-oxide...second layer. Layer transfer produces the best quality devices compared to other additive technologies such as re-crystallization of thin films [148
Function integrated track system
Hohnecker, Eberhard
2010-01-01
The paper discusses a function integrated track system that focuses on the reduction of acoustic emissions from railway lines. It is shown that the combination of an embedded rail system (ERS), a sound absorbing track surface, and an integrated mini sound barrier has significant acoustic advantages compared to a standard ballast superstructure. The acoustic advantages of an embedded rail system are particularly pronounced in the case of railway bridges. Finally, it is shown that a...
Functional integration over geometries
International Nuclear Information System (INIS)
Mottola, E.
1995-01-01
The geometric construction of the functional integral over coset spaces M/G is reviewed. The inner product on the cotangent space of infinitesimal deformations of M defines an invariant distance and volume form, or functional integration measure on the full configuration space. Then, by a simple change of coordinates parameterizing the gauge fiber G, the functional measure on the coset space M/G is deduced. This change of integration variables leads to a Jacobian which is entirely equivalent to the Faddeev--Popov determinant of the more traditional gauge fixed approach in non-abelian gauge theory. If the general construction is applied to the case where G is the group of coordinate reparameterizations of spacetime, the continuum functional integral over geometries, i.e. metrics modulo coordinate reparameterizations may be defined. The invariant functional integration measure is used to derive the trace anomaly and effective action for the conformal part of the metric in two and four dimensional spacetime. In two dimensions this approach generates the Polyakov--Liouville action of closed bosonic non-critical string theory. In four dimensions the corresponding effective action leads to novel conclusions on the importance of quantum effects in gravity in the far infrared, and in particular, a dramatic modification of the classical Einstein theory at cosmological distance scales, signaled first by the quantum instability of classical de Sitter spacetime. Finite volume scaling relations for the functional integral of quantum gravity in two and four dimensions are derived, and comparison with the discretized dynamical triangulation approach to the integration over geometries are discussed. Outstanding unsolved problems in both the continuum definition and the simplicial approach to the functional integral over geometries are highlighted
DEFF Research Database (Denmark)
Frederiksen, Hanne Winther; Nørredam, Marie
Afsnit i Social- og Integrationsministeriets årlige publikation "Fakta om integration". Bygger på et litteraturreview foretaget i 2012 i samarbejde med Forskningscenter for Migration, Etnicitet og Sundhed (MESU) på opdrag af Social- og Integrationsministeriet.......Afsnit i Social- og Integrationsministeriets årlige publikation "Fakta om integration". Bygger på et litteraturreview foretaget i 2012 i samarbejde med Forskningscenter for Migration, Etnicitet og Sundhed (MESU) på opdrag af Social- og Integrationsministeriet....
Experimental integrated photovoltaic systems
International Nuclear Information System (INIS)
Pop-Jordanov, Jordan; Markovska, Natasha; Dimitrov, D.; Kocev, K.; Dimitrovski, D.
2000-01-01
Recently, the interest in building-integrated photovoltaic installations has started to increase within governmental and municipality authorities, as well as some industrial companies. To serve a national public-awareness program of solar electricity promotion and education, the indigenous solar energy potential, optimization of possible PV installation, and three test cases of building-integrated grid-connected experimental facilities have been studied. The results showed the feasibility and performance of the proposed concepts. (Original)
Czech Academy of Sciences Publication Activity Database
Mesiar, Radko; Li, J.; Pap, E.
2013-01-01
Roč. 54, č. 3 (2013), s. 357-364 ISSN 0888-613X R&D Projects: GA ČR GAP402/11/0378 Institutional support: RVO:67985556 Keywords : concave integral * pseudo-addition * pseudo-multiplication Subject RIV: BA - General Mathematics Impact factor: 1.977, year: 2013 http://library.utia.cas.cz/separaty/2013/E/mesiar-discrete pseudo-integrals.pdf
Integrative Pedagogical Bioethics
Directory of Open Access Journals (Sweden)
Anna Hubenko
2014-07-01
Full Text Available The state of bioethics in Ukraine, as well as in the world has been analyzed in this article. The author offers a model of integrative pedagogical bioethics and substantiates the necessity of the organization of the bioethics education and confirms the topicality of adoption of the new specialty – educator-bioethicist. The author defines the structure and method of the educational process and the new curriculum «Integrative Bioethics» for preparing educator-bioethicist specialist.
DEFF Research Database (Denmark)
Bonde, Hans
2013-01-01
Den dansk-jødiske idrætsforening Hakoah er et godt eksempel på, at idrætten historisk har fungeret som en arena for integration i det danske samfund.......Den dansk-jødiske idrætsforening Hakoah er et godt eksempel på, at idrætten historisk har fungeret som en arena for integration i det danske samfund....
Karlefors, Inger; Hertting, Krister
2010-01-01
Competitive sport is a global phenomenon with a common language, but at the same time locally embedded in the national culture. The global character gives competitive sport an attraction, which can create an important arena for integration when people arrive to a new country. Problems can rise when diverse expectations and images meet. To create understanding and facilitate integration for children and youth from different countries it is important to understand which images of sport that is ...
DEFF Research Database (Denmark)
Galiotto, Nicolas; Heiselberg, Per; Knudstrup, Mary-Ann
2016-01-01
renovation to be overcome. The homeowners were better integrated and their preferences and immaterial values were better taken into account. To keep the decision-making process economically viable and timely, the process as known today still needs to be improved, and new tools need to be developed....... This paper presents a new scheme: the integrated renovation process. One successful case study is introduced, and recommendations for future developments needed in the field are provided....
Fostering Integrity in Research
McNutt, M. K.
2017-12-01
The responsible conduct of research requires that all involved in the research enterprise - researchers, sponsors, reviewers, publishers, and communicators - adhere to a set of integrity principles to protect the public's investment. Given the increasing complexity and globalization of the research enterprise, the National Academies recently re-examined and updated its integrity recommendations for researchers in the report Fostering Integrity in Research, with sponsorship from the National Science Foundation. Major departures from the previous recommendations 25-years earlier are the recognition that practices that were previously classified as merely questionable are indeed detrimental to the responsible conduct of research. Furthermore, the report concludes that there has been insufficient effort to respond to the threats that lapses in research integrity pose to the quality of research products and the reputation of researchers as deserving of the public trust. It recommends the creation of an independent, non-profit entity dedicated to promoting research integrity by serving as a resource and clearing house for expertise, advice, materials, and best practices on fostering research integrity and responding to allegations of research misconduct.
Integrated smart structures wingbox
Simon, Solomon H.
1993-09-01
One objective of smart structures development is to demonstrate the ability of a mechanical component to monitor its own structural integrity and health. Achievement of this objective requires the integration of different technologies, i.e.: (1) structures, (2) sensors, and (3) artificial intelligence. We coordinated a team of experts from these three fields. These experts used reliable knowledge towards the forefront of their technologies and combined the appropriate features into an integrated hardware/software smart structures wingbox (SSW) test article. A 1/4 in. hole was drilled into the SSW test article. Although the smart structure had never seen damage of this type, it correctly recognized and located the damage. Based on a knowledge-based simulation, quantification and assessment were also carried out. We have demonstrated that the SSW integrated hardware & software test article can perform six related functions: (1) identification of a defect; (2) location of the defect; (3) quantification of the amount of damage; (4) assessment of performance degradation; (5) continued monitoring in spite of damage; and (6) continuous recording of integrity data. We present the successful results of the integrated test article in this paper, along with plans for future development and deployment of the technology.
Calhoun, Tracy; Melendrez, Dave
2014-01-01
The Human Exploration Science Office (KX) provides leadership for NASA's Imagery Integration (Integration 2) Team, an affiliation of experts in the use of engineering-class imagery intended to monitor the performance of launch vehicles and crewed spacecraft in flight. Typical engineering imagery assessments include studying and characterizing the liftoff and ascent debris environments; launch vehicle and propulsion element performance; in-flight activities; and entry, landing, and recovery operations. Integration 2 support has been provided not only for U.S. Government spaceflight (e.g., Space Shuttle, Ares I-X) but also for commercial launch providers, such as Space Exploration Technologies Corporation (SpaceX) and Orbital Sciences Corporation, servicing the International Space Station. The NASA Integration 2 Team is composed of imagery integration specialists from JSC, the Marshall Space Flight Center (MSFC), and the Kennedy Space Center (KSC), who have access to a vast pool of experience and capabilities related to program integration, deployment and management of imagery assets, imagery data management, and photogrammetric analysis. The Integration 2 team is currently providing integration services to commercial demonstration flights, Exploration Flight Test-1 (EFT-1), and the Space Launch System (SLS)-based Exploration Missions (EM)-1 and EM-2. EM-2 will be the first attempt to fly a piloted mission with the Orion spacecraft. The Integration 2 Team provides the customer (both commercial and Government) with access to a wide array of imagery options - ground-based, airborne, seaborne, or vehicle-based - that are available through the Government and commercial vendors. The team guides the customer in assembling the appropriate complement of imagery acquisition assets at the customer's facilities, minimizing costs associated with market research and the risk of purchasing inadequate assets. The NASA Integration 2 capability simplifies the process of securing one
Integrating the Integrators - A Roadmap to Success
International Nuclear Information System (INIS)
Olson, Craig Stott; Conner, Craig C
1999-01-01
The U.S. Department of Energy Environmental Management's (DOE-EM) investments in science and technology, as well as science and technology investments associated with other parts of the DOE are aimed at meeting the Departments cleanup goals. These investments, primarily focused on EM's cleanup mission, comprise the Environmental Quality Research and Development (R and D) portfolios. Synchronizing EM's Cleanup Project Managers (operations facility and process owners throughout the DOE complex) operational needs with EM R and D including the extensive work of the six Focus Areas (major thrust areas within DOE-EM) has been a continuing challenge. This recent initiative to better integrate the R and D program is in response to evolving needs within the Department to apply proven system engineering methods to clarify requirements and define EM's process to effectively orchestrate their R and D Program. To optimize this partnership, DOE-EM's Integration Program is successfully unifying the operational needs with the R and D as described in this paper
Economic integration in the Americas
Uitdewilligen, G.
1997-01-01
This pioneering study shows that economic integration in the Americas is not simply a matter of removing trade barriers. Economic Integration in the Americas addresses the pervasive effects of economic integration on the economy as a whole.
Necessity of Integral Formalism
International Nuclear Information System (INIS)
Tao Yong
2011-01-01
To describe the physical reality, there are two ways of constructing the dynamical equation of field, differential formalism and integral formalism. The importance of this fact is firstly emphasized by Yang in case of gauge field [Phys. Rev. Lett. 33 (1974) 445], where the fact has given rise to a deeper understanding for Aharonov-Bohm phase and magnetic monopole [Phys. Rev. D 12 (1975) 3845]. In this paper we shall point out that such a fact also holds in general wave function of matter, it may give rise to a deeper understanding for Berry phase. Most importantly, we shall prove a point that, for general wave function of matter, in the adiabatic limit, there is an intrinsic difference between its integral formalism and differential formalism. It is neglect of this difference that leads to an inconsistency of quantum adiabatic theorem pointed out by Marzlin and Sanders [Phys. Rev. Lett. 93 (2004) 160408]. It has been widely accepted that there is no physical difference of using differential operator or integral operator to construct the dynamical equation of field. Nevertheless, our study shows that the Schrödinger differential equation (i.e., differential formalism for wave function) shall lead to vanishing Berry phase and that the Schrödinger integral equation (i.e., integral formalism for wave function), in the adiabatic limit, can satisfactorily give the Berry phase. Therefore, we reach a conclusion: There are two ways of describing physical reality, differential formalism and integral formalism; but the integral formalism is a unique way of complete description. (general)
A Comprehensive Theory of Integration.
Singer, Sara J; Kerrissey, Michaela; Friedberg, Mark; Phillips, Russell
2018-03-01
Efforts to transform health care delivery to improve care have increasingly focused on care integration. However, variation in how integration is defined has complicated efforts to design, synthesize, and compare studies of integration in health care. Evaluations of integration initiatives would be enhanced by describing them according to clear definitions of integration and specifying which empirical relationships they seek to test-whether among types of integration or between integration and outcomes of care. Drawing on previous work, we present a comprehensive theoretical model of relationships between types of integration and propose how to measure them.
Reconfigurable Integrated Optoelectronics
Directory of Open Access Journals (Sweden)
Richard Soref
2011-01-01
Full Text Available Integrated optics today is based upon chips of Si and InP. The future of this chip industry is probably contained in the thrust towards optoelectronic integrated circuits (OEICs and photonic integrated circuits (PICs manufactured in a high-volume foundry. We believe that reconfigurable OEICs and PICs, known as ROEICs and RPICs, constitute the ultimate embodiment of integrated photonics. This paper shows that any ROEIC-on-a-chip can be decomposed into photonic modules, some of them fixed and some of them changeable in function. Reconfiguration is provided by electrical control signals to the electro-optical building blocks. We illustrate these modules in detail and discuss 3D ROEIC chips for the highest-performance signal processing. We present examples of our module theory for RPIC optical lattice filters already constructed, and we propose new ROEICs for directed optical logic, large-scale matrix switching, and 2D beamsteering of a phased-array microwave antenna. In general, large-scale-integrated ROEICs will enable significant applications in computing, quantum computing, communications, learning, imaging, telepresence, sensing, RF/microwave photonics, information storage, cryptography, and data mining.
Integrated care information technology.
Rowe, Ian; Brimacombe, Phil
2003-02-21
Counties Manukau District Health Board (CMDHB) uses information technology (IT) to drive its Integrated Care strategy. IT enables the sharing of relevant health information between care providers. This information sharing is critical to closing the gaps between fragmented areas of the health system. The tragic case of James Whakaruru demonstrates how people have been falling through those gaps. The starting point of the Integrated Care strategic initiative was the transmission of electronic discharges and referral status messages from CMDHB's secondary provider, South Auckland Health (SAH), to GPs in the district. Successful pilots of a Well Child system and a diabetes disease management system embracing primary and secondary providers followed this. The improved information flowing from hospital to GPs now enables GPs to provide better management for their patients. The Well Child system pilot helped improve reported immunization rates in a high health need area from 40% to 90%. The diabetes system pilot helped reduce the proportion of patients with HbA1c rang:9 from 47% to 16%. IT has been implemented as an integral component of an overall Integrated Care strategic initiative. Within this context, Integrated Care IT has helped to achieve significant improvements in care outcomes, broken down barriers between health system silos, and contributed to the establishment of a system of care continuum that is better for patients.
DEFF Research Database (Denmark)
Markvorsen, Steen
2010-01-01
Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum-integraler. Udgangspu......Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum......-integralerne. Undervejs introduceres \\texttt{Integrator8}. Det er en pakke med Maple procedurer, som er udviklet specielt med henblik på eksempelbaseret visuel læring af de indledende integrationsbegreber og deres mangfoldige anvendelser. Vi giver eksempler på, hvordan integration i flere variable anvendes til beregning...... og forståelse af rumfang, vægt, massemidtpunkter, inertimomenter, kraftmomenter, etc. Flowkurverne for et givet vektorfelt i rummet kan findes og visualiseres med \\texttt{Integrator8}. De vigtige begreber divergens og rotation for et vektorfelt fremtræder derved som naturlige størrelser til...
International Nuclear Information System (INIS)
Frost, W.
2007-01-01
This presentation described the role of the Alberta Electric System Operator (AESO) for Alberta's interconnected electric system with particular reference to wind integration in Alberta. The challenges of wind integration were discussed along with the requirements for implementing the market and operational framework. The AESO is an independent system operator that directs the reliable operation of Alberta's power grid; develops and operates Alberta's real-time wholesale energy market to promote open competition; plans and develops the province's transmission system to ensure reliability; and provides transmission system access for both generation and load customers. Alberta has over 280 power generating station, with a total generating capacity of 11,742 MW, of which 443 is wind generated. Since 2004, the AESO has been working with industry on wind integration issues, such as operating limits, need for mitigation measures and market rules. In April 2006, the AESO implemented a temporary 900 MW reliability threshold to ensure reliability. In 2006, a Wind Forecasting Working Group was created in collaboration with industry and the Canadian Wind Energy Association in an effort to integrate as much wind as is feasible without compromising the system reliability or the competitive operation of the market. The challenges facing wind integration include reliability issues; predictability of wind power; the need for dispatchable generation; transmission upgrades; and, defining a market and operational framework for the large wind potential in Alberta. It was noted that 1400 MW of installed wind energy capacity can be accommodated in Alberta with approved transmission upgrades. figs
Integrated Budget Office Toolbox
Rushing, Douglas A.; Blakeley, Chris; Chapman, Gerry; Robertson, Bill; Horton, Allison; Besser, Thomas; McCarthy, Debbie
2010-01-01
The Integrated Budget Office Toolbox (IBOT) combines budgeting, resource allocation, organizational funding, and reporting features in an automated, integrated tool that provides data from a single source for Johnson Space Center (JSC) personnel. Using a common interface, concurrent users can utilize the data without compromising its integrity. IBOT tracks planning changes and updates throughout the year using both phasing and POP-related (program-operating-plan-related) budget information for the current year, and up to six years out. Separating lump-sum funds received from HQ (Headquarters) into separate labor, travel, procurement, Center G&A (general & administrative), and servicepool categories, IBOT creates a script that significantly reduces manual input time. IBOT also manages the movement of travel and procurement funds down to the organizational level and, using its integrated funds management feature, helps better track funding at lower levels. Third-party software is used to create integrated reports in IBOT that can be generated for plans, actuals, funds received, and other combinations of data that are currently maintained in the centralized format. Based on Microsoft SQL, IBOT incorporates generic budget processes, is transportable, and is economical to deploy and support.
Impairments in Skin Integrity.
Murphree, Rose W
2017-09-01
Altered skin integrity increases the chance of infection, impaired mobility, and decreased function and may result in the loss of limb or, sometimes, life. Skin is affected by both intrinsic and extrinsic factors. Intrinsic factors can include altered nutritional status, vascular disease issues, and diabetes. Extrinsic factors include falls, accidents, pressure, immobility, and surgical procedures. Ensuring skin integrity in the elderly requires a team approach and includes the individual, caregivers, and clinicians. The twenty-first century clinician has several online, evidence-based tools to assist with optimal treatment plans. Understanding best practices in addressing skin integrity issues can promote positive outcomes with the elderly. Copyright © 2017 Elsevier Inc. All rights reserved.
ADDRESS SYSTEM INTEGRATION BUSINESS
Directory of Open Access Journals (Sweden)
Lionel Manuel Carbonell-Zamora
2016-01-01
Full Text Available The Integrated Strategic Direction constitutes a superior stage of Direction that expresses the coordinated system of external and internal relations with full participation in order to reach the vision of the organization. It can be insured by the use of the Strategic Direction model for the integration of the Company Direction System. This model has been applied in several companies. Recently, it was applied in the Inspection State Unit of MICONS in Santiago de Cuba through the investigation thesis for master degree developed during 18 months which objective was to validate its effectiveness in a budgeted unit, obtaining positive results when the levels of integration in the direction system increased in their external and internal relations expressed in a 37 % and 15 % respectively, which impacted the increment of the efficiency and effectiveness of all processes of the organization.
Signal integrity characterization techniques
Bogatin, Eric
2009-01-01
"Signal Integrity Characterization Techniques" addresses the gap between traditional digital and microwave curricula all while focusing on a practical and intuitive understanding of signal integrity effects within the data transmission channel. High-speed interconnects such as connectors, PCBs, cables, IC packages, and backplanes are critical elements of differential channels that must be designed using today's most powerful analysis and characterization tools.Both measurements and simulation must be done on the device under test, and both activities must yield data that correlates with each other. Most of this book focuses on real-world applications of signal integrity measurements - from backplane for design challenges to error correction techniques to jitter measurement technologies. The authors' approach wisely addresses some of these new high-speed technologies, and it also provides valuable insight into its future direction and will teach the reader valuable lessons on the industry.
Integrative Scenario Development
Directory of Open Access Journals (Sweden)
Joerg A. Priess
2014-03-01
Full Text Available Scenarios are employed to address a large number of future environmental and socioeconomic challenges. We present a conceptual framework for the development of scenarios to integrate the objectives of different stakeholder groups. Based on the framework, land-use scenarios were developed to provide a common base for further research. At the same time, these scenarios assisted regional stakeholders to bring forward their concerns and arrive at a shared understanding of challenges between scientific and regional stakeholders, which allowed them to eventually support regional decision making. The focus on the integration of views and knowledge domains of different stakeholder groups, such as scientists and practitioners, required rigorous and repeated measures of quality control. The application of the integrative concept provided products for both stakeholder groups, and the process of scenario development facilitated cooperation and learning within both the scientist and practitioner groups as well as between the two groups.
DEFF Research Database (Denmark)
Rezaei, Shahamak; Goli, Marco
2012-01-01
Integration or illusion – a deviance perspective Denmark experienced one of its most successful periods of economic growth in 2004–2008 with a tremendous reduction of unemployment, which in June 2008 was around. 1.5 percent, far below the expected level of structural unemployment. In the wake...... of migrants’ skills. 2. Whether there were patterns of over-education as expression of institutional and societal discrimination. The focus of the present study is, however, quite different: We examine the pattern of deviance in relation to labour market participation (not integration), and instead...... of searching for explanations for the lack of integration, we attempt to identify and explain the deviance pattern as a product of institutionally inherent possibilities and barriers on the one hand and articulating immigrants as rational actors (not victims) on the other. We argue that deviance is not only...
An integrated magnetics component
DEFF Research Database (Denmark)
2013-01-01
The present invention relates to an integrated magnetics component comprising a magnetically permeable core comprising a base member extending in a horizontal plane and first, second, third and fourth legs protruding substantially perpendicularly from the base member. First, second, third...... and fourth output inductor windings are wound around the first, second, third and fourth legs, respectively. A first input conductor of the integrated magnetics component has a first conductor axis and extends in-between the first, second, third and fourth legs to induce a first magnetic flux through a first...... flux path of the magnetically permeable core. A second input conductor of the integrated magnetics component has a second coil axis extending substantially perpendicularly to the first conductor axis to induce a second magnetic flux through a second flux path of the magnetically permeable core...
DEFF Research Database (Denmark)
Rytter, Mikkel
2018-01-01
The article addresses some of the problems related to the concept of integration, which has been used (and abused) in Denmark since the 1980s to discuss socio-economic, cultural and religious challenges related to the everyday life of ethnic minorities. The concept of integration is not innocent...... three scenarios: ‘welfare reciprocity’, ‘host and guests’ and ‘the Danes as an indigenous people’. These scenarios consolidate an asymmetrical relationship between majorities and minorities because they simultaneously cast integration as desirable and impossible. Finally, inspired by Lila Abu......-Lughod’s seminal article “writing against culture”, the article suggests strategies of “writing against integration” in order to regain the critical potential of academic analysis....
Semantic Observation Integration
Directory of Open Access Journals (Sweden)
Werner Kuhn
2012-09-01
Full Text Available Although the integration of sensor-based information into analysis and decision making has been a research topic for many years, semantic interoperability has not yet been reached. The advent of user-generated content for the geospatial domain, Volunteered Geographic Information (VGI, makes it even more difficult to establish semantic integration. This paper proposes a novel approach to integrating conventional sensor information and VGI, which is exploited in the context of detecting forest fires. In contrast to common logic-based semantic descriptions, we present a formal system using algebraic specifications to unambiguously describe the processing steps from natural phenomena to value-added information. A generic ontology of observations is extended and profiled for forest fire detection in order to illustrate how the sensing process, and transformations between heterogeneous sensing systems, can be represented as mathematical functions and grouped into abstract data types. We discuss the required ontological commitments and a possible generalization.
INTEGRATED CORPORATE STRATEGY MODEL
Directory of Open Access Journals (Sweden)
CATALINA SORIANA SITNIKOV
2014-02-01
Full Text Available Corporations are at present operating in demanding and highly unsure periods, facing a mixture of increased macroeconomic need, competitive and capital market dangers, and in many cases, the prospect for significant technical and regulative gap. Throughout these demanding and highly unsure times, the corporations must pay particular attention to corporate strategy. In present times, corporate strategy must be perceived and used as a function of various fields, covers, and characters as well as a highly interactive system. For the corporation's strategy to become a competitive advantage is necessary to understand and also to integrate it in a holistic model to ensure sustainable progress of corporation activities under the optimum conditions of profitability. The model proposed in this paper is aimed at integrating the two strategic models, Hoshin Kanri and Integrated Strategy Model, as well as their consolidation with the principles of sound corporate governance set out by the OECD.