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Sample records for higher-order rewrite systems

  1. Proving termination of Higher-Order Rewrite Systems

    NARCIS (Netherlands)

    Pol, J.C. van de

    1993-01-01

    This paper deals with termination proofs for Higher-Order Rewrite Systems (HRSs), introduced in [Nip9l, Nip93]. This formalism combines the computational aspects of term rewriting and simply typed lambda calculus. Our result is a proof technique for the termination of a HRS, similar to the proof tec

  2. Higher-Order Rewriting and Partial Evaluation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Rose, Kristoffer H.

    1997-01-01

    We demonstrate the usefulness of higher-order rewriting techniques for specializing programs, i.e., for partial evaluation. More precisely, we demonstrate how casting program specializers as combinatory reduction systems (CRSs) makes it possible to formalize the corresponding program...... for additional restrictions such as types that would complicate the description unnecessarily (for our purpose). In addition, partial evaluation provides a number of examples of higher-order rewriting where being higher order is a central (rather than an occasional or merely exotic) property. We illustrate...... this by demonstrating how standard but non-trivial partial-evaluation examples are handled with higher-order rewriting....

  3. Static Dependency Pair Method based on Strong Computability for Higher-Order Rewrite Systems

    CERN Document Server

    Kusakari, Keiichirou; Sakai, Masahiko; Blanqui, Frédéric

    2011-01-01

    Higher-order rewrite systems (HRSs) and simply-typed term rewriting systems (STRSs) are computational models of functional programs. We recently proposed an extremely powerful method, the static dependency pair method, which is based on the notion of strong computability, in order to prove termination in STRSs. In this paper, we extend the method to HRSs. Since HRSs include \\lambda-abstraction but STRSs do not, we restructure the static dependency pair method to allow \\lambda-abstraction, and show that the static dependency pair method also works well on HRSs without new restrictions.

  4. Higher-order rewriting and partial evaluation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Rose, Kristoffer H.

    1998-01-01

    transformations as meta-reductions, i.e., reductions in the internal “substitution calculus.” For partial-evaluation problems, this means that instead of having to prove on a case-by-case basis that one's “two-level functions” operate properly, one can concisely formalize them as a combinatory reduction system...... and obtain as a corollary that static reduction does not go wrong and yields a well-formed residual program. We have found that the CRS substitution calculus provides an adequate expressive power to formalize partial evaluation: it provides sufficient termination strength while avoiding the need...

  5. A proof of finite family developments for higher-order rewriting using a prefix property

    NARCIS (Netherlands)

    Bruggink, H.J.S.

    2006-01-01

    A prefix property is the property that, given a reduction, the ancestor of a prefix of the target is a prefix of the source. In this paper we prove a prefix property for the class of Higher-Order Rewriting Systems with patterns (HRSs), by reducing it to a similar prefix property of a λ-calculus with

  6. Higher-order (non-)modularity

    NARCIS (Netherlands)

    Appel, Claus; Oostrom, V. van; Grue Simonsen, Jakob

    2010-01-01

    We show that, contrary to the situation in first-order term rewriting, almost none of the usual properties of rewriting are modular for higher-order rewriting, irrespective of the higher-order rewriting format. For the particular format of simply typed applicative term rewriting systems we prove tha

  7. Higher order resonances in dynamical systems

    CERN Document Server

    Contopoulos, George

    1978-01-01

    It is shown that the appearance of higher order resonances (that produce higher order islands on a surface of section), is not an indication of non-integrability. Examples are given and a method is described for constructing integrable Hamiltonians with higher order resonances. (11 refs).

  8. Dynamic analysis of higher order biological systems.

    Science.gov (United States)

    Sato, K

    1981-01-01

    Humans and animals consist of a variety of bio-systems exhibiting various bio-phenomena over the course of time, from the past to the present and into future, up to just before their death. Each state of a bio-phenomenon at any time is related in stochastic fashion not only to its past history, but those of many other bio- and natural phenomena, enormous in number, in their internal and external environments. Most states of these bio-phenomena sway more or less around respective averages, which suggest their levels of homeostasis, essentially important for maintaining life. In the above past history of sway was hidden an essential characteristic, i.e., dynamic higher-order activity, of the bio-system, whereas the bio- and natural phenomena in the environments act to drive, i.e., stimulate, as an ensemble, the bio-system to exhibit the bio-phenomena as its responses. From this new point of view, mono- and multivariate dynamic stimulation-system (activity)-response relations in stochastic fashion can be seen as an extension leading from of one of the most fundamental static laws of excitability, that is the threshold stimulus-excitability-unit response relation in physiology. The dynamic mono- and multivariate higher-order activities, each of which consisted of some first- and second-order component activities, can be described in the frequency and time-patterns as the power spectral densities or frequency responses and (unit) impulse responses, respectively. Some of these "dynamic activities" were manifested in the brain system of humans and cats, the human "posture holding system," "the pressure regulatory system" in the human pulmonary circulation and the "glucoregulatory system" of dogs, respectively.

  9. Rewriting Modulo SMT and Open System Analysis

    Science.gov (United States)

    Rocha, Camilo; Meseguer, Jose; Munoz, Cesar

    2014-01-01

    This paper proposes rewriting modulo SMT, a new technique that combines the power of SMT solving, rewriting modulo theories, and model checking. Rewriting modulo SMT is ideally suited to model and analyze infinite-state open systems, i.e., systems that interact with a non-deterministic environment. Such systems exhibit both internal non-determinism, which is proper to the system, and external non-determinism, which is due to the environment. In a reflective formalism, such as rewriting logic, rewriting modulo SMT can be reduced to standard rewriting. Hence, rewriting modulo SMT naturally extends rewriting-based reachability analysis techniques, which are available for closed systems, to open systems. The proposed technique is illustrated with the formal analysis of: (i) a real-time system that is beyond the scope of timed-automata methods and (ii) automatic detection of reachability violations in a synchronous language developed to support autonomous spacecraft operations.

  10. Developing Higher-Order Materials Knowledge Systems

    Science.gov (United States)

    Fast, Anthony Nathan

    2011-12-01

    Advances in computational materials science and novel characterization techniques have allowed scientists to probe deeply into a diverse range of materials phenomena. These activities are producing enormous amounts of information regarding the roles of various hierarchical material features in the overall performance characteristics displayed by the material. Connecting the hierarchical information over disparate domains is at the crux of multiscale modeling. The inherent challenge of performing multiscale simulations is developing scale bridging relationships to couple material information between well separated length scales. Much progress has been made in the development of homogenization relationships which replace heterogeneous material features with effective homogenous descriptions. These relationships facilitate the flow of information from lower length scales to higher length scales. Meanwhile, most localization relationships that link the information from a from a higher length scale to a lower length scale are plagued by computationally intensive techniques which are not readily integrated into multiscale simulations. The challenge of executing fully coupled multiscale simulations is augmented by the need to incorporate the evolution of the material structure that may occur under conditions such as material processing. To address these challenges with multiscale simulation, a novel framework called the Materials Knowledge System (MKS) has been developed. This methodology efficiently extracts, stores, and recalls microstructure-property-processing localization relationships. This approach is built on the statistical continuum theories developed by Kroner that express the localization of the response field at the microscale using a series of highly complex convolution integrals, which have historically been evaluated analytically. The MKS approach dramatically improves the accuracy of these expressions by calibrating the convolution kernels in these

  11. Skinner-Rusk unified formalism for higher-order systems

    Science.gov (United States)

    Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

    2012-07-01

    The Lagrangian-Hamiltonian unified formalism of R. Skinner and R. Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, first-order and higher-order field theories, and higher-order autonomous systems. In this work we present a generalization of this formalism for higher-order non-autonomous mechanical systems.

  12. Modeling of higher order systems using artificial bee colony algorithm

    Directory of Open Access Journals (Sweden)

    Aytekin Bağış

    2016-05-01

    Full Text Available In this work, modeling of the higher order systems based on the use of the artificial bee colony (ABC algorithm were examined. Proposed model parameters for the sample systems in the literature were obtained by using the algorithm, and its performance was presented comparatively with the other methods. Simulation results show that the ABC algorithm based system modeling approach can be used as an efficient and powerful method for higher order systems.

  13. Blind graph rewriting systems

    CERN Document Server

    Salikhmetov, Anton

    2012-01-01

    We consider a simple (probably, the simplest) structure for random access memory. This structure can be used to construct a universal system with nearly void processor, namely, we demonstrate that the processor of such a system may have empty instruction set, in a more strong manner than the existing ZISC (zero instruction set computer based on ideas for artificial neural networks) and NISC architecture (no instruction set computing). More precisely, the processor will be forbidden to analyze any information stored in the memory, the latter being the only state of such a machine. This particular paper is to cover an isolated aspect of the idea, specifically, to provide the logical operations embedded into a system without any built-in conditional statements.

  14. Dynamics and control of higher-order nonholonomic systems

    Science.gov (United States)

    Rubio Hervas, Jaime

    A theoretical framework is established for the control of higher-order nonholonomic systems, defined as systems that satisfy higher-order nonintegrable constraints. A model for such systems is developed in terms of differential-algebraic equations defined on a higher-order tangent bundle. A number of control-theoretic properties such as nonintegrability, controllability, and stabilizability are presented. Higher-order nonholonomic systems are shown to be strongly accessible and, under certain conditions, small time locally controllable at any equilibrium. There are important examples of higher-order nonholonomic systems that are asymptotically stabilizable via smooth feedback, including space vehicles with multiple slosh modes and Prismatic-Prismatic-Revolute (PPR) robots moving open liquid containers, as well as an interesting class of systems that do not admit asymptotically stabilizing continuous static or dynamic state feedback. Specific assumptions are introduced to define this class, which includes important examples of robotic systems. A discontinuous nonlinear feedback control algorithm is developed to steer any initial state to the equilibrium at the origin. The applicability of the theoretical development is illustrated through two examples: control of a planar PPR robot manipulator subject to a jerk constraint and control of a point mass moving on a constant torsion curve in a three dimensional space.

  15. Impulse Controllability : From Descriptor Systems to Higher Order DAEs

    NARCIS (Netherlands)

    Kalpana Kalaimani, Rachel; Praagman, Cornelis; Belur, Madhu N.

    2016-01-01

    Impulsive solutions in LTI dynamical systems have received ample attention, but primarily for descriptor systems, i.e., first order Differential Algebraic Equations (DAEs). This paper focuses on the impulsive behavior of higher order dynamical systems and analyzes the causes of impulses in the conte

  16. The structured controllability radii of higher order systems

    National Research Council Canada - National Science Library

    Son, Nguyen Khoa; Thuan, Do Duc

    2013-01-01

    In this paper we shall deal with the problem of calculation of the controllability radius of higher order dynamical systems of the form Ex.sup.(k)(t)=A.sub.k-1x.sup.(k-1)(t)+a[macron]+A.sub.1x.sup.(1)(t)+A.sub.0x(t)+Bu...

  17. Higher-Order (Non-)Modularity

    DEFF Research Database (Denmark)

    Appel, Claus; van Oostrom, Vincent; Simonsen, Jakob Grue

    2010-01-01

    We show that, contrary to the situation in first-order term rewriting, almost none of the usual properties of rewriting are modular for higher-order rewriting, irrespective of the higher-order rewriting format. We show that for the particular format of simply typed applicative term rewriting syst...

  18. Higher-order (non-)modularity

    DEFF Research Database (Denmark)

    Appel, Claus; van Oostrom, Vincent; Simonsen, Jakob Grue

    2010-01-01

    We show that, contrary to the situation in first-order term rewriting, almost none of the usual properties of rewriting are modular for higher-order rewriting, irrespective of the higher-order rewriting format. We show that for the particular format of simply typed applicative term rewriting syst...

  19. Koch Curves: Rewriting System, Geometry and Application

    Directory of Open Access Journals (Sweden)

    Mamta Rani

    2011-01-01

    Full Text Available Problem statement: Recently, new Koch curves have been generated by dividing the initiator into three unequal parts. There is no formal rewriting system to generate such kind of curves. Approach: It is required to measure the new changed geometrical properties. Generalized rewriting systems for the new Koch curves have been developed. Results: New formulas have been given to measure their geometrical properties. Conclusion/Recommendations: The geometrical properties of new Koch curves make them more suitable as antennas in wireless communication than the conventional Koch curve.

  20. Transfinite reductions in orthogonal term rewriting systems

    NARCIS (Netherlands)

    J.R. Kennaway (Richard); J.W. Klop (Jan Willem); M.R. Sleep (Ronan); F.-J. de Vries (Fer-Jan)

    1991-01-01

    textabstractStrongly convergent reduction is the fundamental notion of reduction in infinitary orthogonal term rewriting systems (OTRSs). For these we prove the Transfinite Parallel Moves Lemma and the Compressing Lemma. Strongness is necessary as shown by counterexamples. Normal forms, which we

  1. Phase structure rewrite systems in information retrieval

    Science.gov (United States)

    Klingbiel, P. H.

    1985-01-01

    Operational level automatic indexing requires an efficient means of normalizing natural language phrases. Subject switching requires an efficient means of translating one set of authorized terms to another. A phrase structure rewrite system called a Lexical Dictionary is explained that performs these functions. Background, operational use, other applications and ongoing research are explained.

  2. Continuity in weak topology: higher order linear systems of ODE

    Institute of Scientific and Technical Information of China (English)

    ZHANG MeiRong

    2008-01-01

    We will introduce a type of Fredholm operators which are shown to have a certain continuity in weak topologies. From this, we will prove that the fundamental matrix solutions of k-th,k≥ 2, order linear systems of ordinary differential equations are continuous in coefficient matrixes with weak topologies. Consequently, Floquet multipliers and Lyapunov exponents for periodic systems are continuous in weak topologies. Moreover, for the scalar Hill's equations, Sturm-Liouville eigenvalues,periodic and anti-periodic eigenvalues, and rotation numbers are all continuous in potentials with weak topologies. These results will lead to many interesting variational problems.

  3. Higher-Order Singular Systems and Polynomial Matrices

    OpenAIRE

    2005-01-01

    There is a one-to-one correspondence between the set of quadruples of matrices defining singular linear time-invariant dynamical systems and a subset of the set of polynomial matrices. This correspondence preserves the equivalence relations introduced in both sets (feedback-similarity and strict equivalence): two quadruples of matrices are feedback-equivalent if, and only if, the polynomial matrices associated to them are also strictly equivalent. Los sistemas lineales singulares...

  4. Termination of canonical context-sensitive rewriting and productivity of rewrite systems

    Directory of Open Access Journals (Sweden)

    Salvador Lucas

    2015-12-01

    Full Text Available Termination of programs, i.e., the absence of infinite computations, ensures the existence of normal forms for all initial expressions, thus providing an essential ingredient for the definition of a normalization semantics for functional programs. In lazy functional languages, though, infinite data structures are often delivered as the outcome of computations. For instance, the list of all prime numbers can be returned as a neverending stream of numerical expressions or data structures. If such streams are allowed, requiring termination is hopeless. In this setting, the notion of productivity can be used to provide an account of computations with infinite data structures, as it "captures the idea of computability, of progress of infinite-list programs" (B.A. Sijtsma, On the Productivity of Recursive List Definitions, ACM Transactions on Programming Languages and Systems 11(4:633-649, 1989. However, in the realm of Term Rewriting Systems, which can be seen as (first-order, untyped, unconditional functional programs, termination of Context-Sensitive Rewriting (CSR has been showed equivalent to productivity of rewrite systems through appropriate transformations. In this way, tools for proving termination of CSR can be used to prove productivity. In term rewriting, CSR is the restriction of rewriting that arises when reductions are allowed on selected arguments of function symbols only. In this paper we show that well-known results about the computational power of CSR are useful to better understand the existing connections between productivity of rewrite systems and termination of CSR, and also to obtain more powerful techniques to prove productivity of rewrite systems.

  5. Directed animals, quadratic and rewriting systems

    CERN Document Server

    Marckert, Jean-François

    2011-01-01

    A directed animal is a percolation cluster in the directed site percolation model. The aim of this paper is to exhibit a strong relation between in one hand, the problem of computing the generating function $\\G$ of directed animals on the square lattice, counted according to the area and the perimeter, and on the other hand, the problem to find a solution to a system of quadratic equations involving unknown matrices. The matrices solution of this problem can be finite or infinite. We were unable to find finite solutions. We present some solid clues that some infinite explicit matrices, fix points of a rewriting like system are the natural solutions of this system of equations: some strong evidences are given that the problem of finding $\\G$ reduces then to the problem of finding an eigenvector to an explicit infinite matrix. Similar properties are shown for other combinatorial questions concerning directed animals, and for different lattices.

  6. Well limit behaviors of term rewriting systems

    Institute of Scientific and Technical Information of China (English)

    MA Shilong; SUI Yuefei; XU Ke

    2007-01-01

    The limit behaviors of computations have not been fully explored.It is necessary to consider such limit behaviors when we consider the properties of infinite objects in computer science,such as infinite logic programs,the symbolic solutions of infinite polynomial equations.Usually,we can use finite objects to approximate infinite objects,and we should know what kinds of infinite objects are approximable and how to approximate them effectively.A sequence {Rκ:κω}of term rewriting systems has the well limit behavior if under the condition that the sequence has the Set-theoretic limit or the distance-based limit,the sequence {Th(Rκ):κ∈ω} of corresponding theoretic closures of Rκ has the set-theoretic or distance-based limit,and limκ→∞ Th(Rκ) is equal to the theoretic closure of the limit of {Rκ:κ∈ω).Two kinds of limits of term rewriting systems are considered:one is based on the set-theoretic limit,the other is on the distance-based limit.It is proved thatgiven a sequence {Rκ:κ∈ω) of term rewriting systems Rκ,if there is a well-founded ordering (-<) on terms such that every Rκ is (-<)-well-founded,and the set-theoretic limit of {Rκ:κ∈ω).exists,then {Rκ:κ∈ω).has the well limit behavior;and if (1) there is a well-founded ordering(-<)on terms such that every Rκ is(-<-well-founded,(2) there is a distance d on terms which is closed under substitutions and contexts and (3) {Rκ:κ∈ω).is Cauchy under d then {Rκ:κ∈ω).has the well limit behavior.The results are used to approximate the least Herbrand models of infinite Horn logic programs and real Horn logic programs,and the solutions and Cr(o)bner bases of (infinite) sets of real polynomials by sequences of (finite) sets of rational polynomials.

  7. Cauchy Problem for Quasilinear Hyperbolic Systems with Higher Order Dissipative Terms

    Institute of Scientific and Technical Information of China (English)

    Wei-guo Zhang

    2003-01-01

    In this paper, the author studies the global existence, singularities and life span of smooth solutions of the Cauchy problem for a class of quasilinear hyperbolic systems with higher order dissipative terms and gives their applications to nonlinear wave equations with higher order dissipative terms.

  8. Optimal Control and higher-order mechanics for systems with symmetries

    CERN Document Server

    Colombo, Leonardo; de Diego, David Martin

    2012-01-01

    In this paper we will develop and design numerical methods for optimal control problems for a class of underactuated Lagrangian mechanical systems where the configuration manifold is a trivial principal bundle . We will construct these geometric integrators using discrete variational calculus, deriving a discrete version of the higher-order Euler-Lagrange equations on trivial principal bundles. The analysis applies to systems subject to higher-order constraints (that is, depending of higher-order derivatives as, for example, the acceleration). Interesting applications as, for instance, a discrete derivation of the Euler-Lagrange equations for higher-order Lagrangians and higher-order reduced Lagrangians, respectively, are shown. We find interesting applications both in the optimal control of an underactuated vehicle and the well-known plate ball problem seen as an optimization problem with nonholonomic constraints .

  9. Geometric Integrators for Higher-Order Variational Systems and Their Application to Optimal Control

    Science.gov (United States)

    Colombo, Leonardo; Ferraro, Sebastián; Martín de Diego, David

    2016-12-01

    Numerical methods that preserve geometric invariants of the system, such as energy, momentum or the symplectic form, are called geometric integrators. In this paper we present a method to construct symplectic-momentum integrators for higher-order Lagrangian systems. Given a regular higher-order Lagrangian L:T^{(k)}Q→ R with k≥ 1, the resulting discrete equations define a generally implicit numerical integrator algorithm on T^{(k-1)}Q× T^{(k-1)}Q that approximates the flow of the higher-order Euler-Lagrange equations for L. The algorithm equations are called higher-order discrete Euler-Lagrange equations and constitute a variational integrator for higher-order mechanical systems. The general idea for those variational integrators is to directly discretize Hamilton's principle rather than the equations of motion in a way that preserves the invariants of the original system, notably the symplectic form and, via a discrete version of Noether's theorem, the momentum map. We construct an exact discrete Lagrangian L_d^e using the locally unique solution of the higher-order Euler-Lagrange equations for L with boundary conditions. By taking the discrete Lagrangian as an approximation of L_d^e, we obtain variational integrators for higher-order mechanical systems. We apply our techniques to optimal control problems since, given a cost function, the optimal control problem is understood as a second-order variational problem.

  10. Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-03-01

    In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present simple and efficient closed-form expression to the higher order moments of the channel capacity of dual hop transmission system with Rayleigh fading channels. In order to analyze the behavior of the higher order capacity statistics and investigate the usefulness of the mathematical analysis, some selected numerical and simulation results are presented. Our results are found to be in perfect agreement. © 2012 IEEE.

  11. PRECONDITIONING HIGHER ORDER FINITE ELEMENT SYSTEMS BY ALGEBRAIC MULTIGRID METHOD OF LINEAR ELEMENTS

    Institute of Scientific and Technical Information of China (English)

    Yun-qing Huang; Shi Shu; Xi-jun Yu

    2006-01-01

    We present and analyze a robust preconditioned conjugate gradient method for the higher order Lagrangian finite element systems of a class of elliptic problems. An auxiliary linear element stiffness matrix is chosen to be the preconditioner for higher order finite elements. Then an algebraic multigrid method of linear finite element is applied for solving the preconditioner. The optimal condition number which is independent of the mesh size is obtained. Numerical experiments confirm the efficiency of the algorithm.

  12. Productivity of Non-Orthogonal Term Rewrite Systems

    CERN Document Server

    Raffelsieper, Matthias

    2012-01-01

    Productivity is the property that finite prefixes of an infinite constructor term can be computed using a given term rewrite system. Hitherto, productivity has only been considered for orthogonal systems, where non-determinism is not allowed. This paper presents techniques to also prove productivity of non-orthogonal term rewrite systems. For such systems, it is desired that one does not have to guess the reduction steps to perform, instead any outermost-fair reduction should compute an infinite constructor term in the limit. As a main result, it is shown that for possibly non-orthogonal term rewrite systems this kind of productivity can be concluded from context-sensitive termination. This result can be applied to prove stabilization of digital circuits, as will be illustrated by means of an example.

  13. Objective Reduction Solutions to Higher-Order Boussinesq System in (2+1)-Dimensions

    Institute of Scientific and Technical Information of China (English)

    HU Ya-Hong; ZHENG Chun-Long

    2009-01-01

    With the help of an objective reduction approach (ORA), abundant exact solutions of (2+1)-dimensional higher-order Boussinesq system (including some hyperboloid function solutions, trigonometric function solutions, and a rational function solution) are obtained. It is shown that some novel soliton structures, like single linearity soliton structure, breath soliton structure, single linearity y-periodic solitary wave structure, libration dromion structure, and kink-like multisoliton structure with actual physical meaning exist in the (2+1)-dimensional higher-order Bonssinesq system.

  14. Regularity properties of fiber derivatives associated with higher-order mechanical systems

    Science.gov (United States)

    Colombo, Leonardo; Prieto-Martínez, Pedro Daniel

    2016-08-01

    The aim of this work is to study fiber derivatives associated to Lagrangian and Hamiltonian functions describing the dynamics of a higher-order autonomous dynamical system. More precisely, given a function in T∗T(k-1)Q, we find necessary and sufficient conditions for such a function to describe the dynamics of a kth-order autonomous dynamical system, thus being a kth-order Hamiltonian function. Then, we give a suitable definition of (hyper)regularity for these higher-order Hamiltonian functions in terms of their fiber derivative. In addition, we also study an alternative characterization of the dynamics in Lagrangian submanifolds in terms of the solutions of the higher-order Euler-Lagrange equations.

  15. Lifting Term Rewriting Derivations in Constructor Systems by Using Generators

    Directory of Open Access Journals (Sweden)

    Adrián Riesco

    2015-01-01

    Full Text Available Narrowing is a procedure that was first studied in the context of equational E-unification and that has been used in a wide range of applications. The classic completeness result due to Hullot states that any term rewriting derivation starting from an instance of an expression can be "lifted" to a narrowing derivation, whenever the substitution employed is normalized. In this paper we adapt the generator- based extra-variables-elimination transformation used in functional-logic programming to overcome that limitation, so we are able to lift term rewriting derivations starting from arbitrary instances of expressions. The proposed technique is limited to left-linear constructor systems and to derivations reaching a ground expression. We also present a Maude-based implementation of the technique, using natural rewriting for the on-demand evaluation strategy.

  16. Conformal Invariance of Higher-Order Lagrange Systems by Lie Point Transformation

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei-Li; CAI Jian-Le

    2011-01-01

    Conformal invariance and conserved quantities for a higher-order Lagrange system by Lie point transformation of groups are studied. The differential equation of motion for the higher-order Lagrange system is introduced. The definition of conformal invariance for the system together with its determining equations and conformal factor are provided. The necessary and sufficient condition that the system's conformal invariance would be Lie symmetry by the infinitesimal one-parameter point transformation group is deduced. The conserved quantity of the system is derived using the structural equation satisfied by the gauge function. An example of a higher-order mechanical system is offered to illustrate the application of the result.%Conformal invariance and conserved quantities for a higher-order Lagrange system by Lie point transformation of groups are studied.The differential equation of motion for the higher-order Lagrange system is introduced.The definition of conformal invariance for the system together with its determining equations and conformal factor are provided.The necessary and sufficient condition that the system's conformal invariance would be Lie symmetry by the infinitesimal one-parameter point transformation group is deduced.The conserved quantity of the system is derived using the structural equation satisfied by the gauge function.An example of a higher-order mechanical system is offered to illustrate the application of the result.Since the Noether theorem was published in 1918,[1] the symmetry and conserved quantity for a dynamical system play important roles in the fields of modern science and technology,and some important results have been gained so far.[2-21] Conformal invariance is a modern method for finding conserved quantities.In 1997,Galiullin etal.[22] studied conformal invariance of Birkhoff systems under special infinitesimal transformations.In recent years,we have discussed the conformal invariance of Lie symmetry for Lagrange systems

  17. Impact of ligand protonation on higher-order metal complexation kinetics in aqueous systems

    NARCIS (Netherlands)

    Town, R.M.; Leeuwen, van H.P.

    2008-01-01

    The impact of ligand protonation on the complexation kinetics of higher-order complexes is quantitatively described. The theory is formulated on the basis of the usual situation for metal complex formation in aqueous systems in which the exchange of water for the ligand in the inner coordination sph

  18. Geometric Hamilton-Jacobi theory for higher-order autonomous systems

    Science.gov (United States)

    Colombo, Leonardo; de León, Manuel; Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

    2014-06-01

    The geometric framework for the Hamilton-Jacobi theory is used to study this theory in the background of higher-order mechanical systems, in both the Lagrangian and Hamiltonian formalisms. Thus, we state the corresponding Hamilton-Jacobi equations in these formalisms and apply our results to analyze some particular physical examples.

  19. Impact of ligand protonation on higher-order metal complexation kinetics in aqueous systems

    NARCIS (Netherlands)

    Town, R.M.; Leeuwen, van H.P.

    2008-01-01

    The impact of ligand protonation on the complexation kinetics of higher-order complexes is quantitatively described. The theory is formulated on the basis of the usual situation for metal complex formation in aqueous systems in which the exchange of water for the ligand in the inner coordination sph

  20. m Components-Admissible Solutions of Systems of Higher-Order Partial Differential Equations on Cm

    Institute of Scientific and Technical Information of China (English)

    Ling-yun Gao

    2008-01-01

    Using value distribution theory and techniques in severed complex variables,we investigate the problem of existence of m components-admissible solutions of a class of systems of higher-order partied differential equations in several complex variables and estimate the number of admissible components of solutions.Some related results will also be obtained.

  1. On realization of nonlinear systems described by higher-order differential equations

    NARCIS (Netherlands)

    Schaft, van der A.J.

    1987-01-01

    We consider systems of smooth nonlinear differential and algebraic equations in which some of the variables are distinguished as “external variables.” The realization problem is to replace the higher-order implicit differential equations by first-order explicit differential equations and the algebra

  2. Finite time control for MIMO nonlinear system based on higher-order sliding mode.

    Science.gov (United States)

    Liu, Xiangjie; Han, Yaozhen

    2014-11-01

    Considering a class of MIMO uncertain nonlinear system, a novel finite time stable control algorithm is proposed based on higher-order sliding mode concept. The higher-order sliding mode control problem of MIMO nonlinear system is firstly transformed into finite time stability problem of multivariable system. Then continuous control law, which can guarantee finite time stabilization of nominal integral chain system, is employed. The second-order sliding mode is used to overcome the system uncertainties. High frequency chattering phenomenon of sliding mode is greatly weakened, and the arbitrarily fast convergence is reached. The finite time stability is proved based on the quadratic form Lyapunov function. Examples concerning the triple integral chain system with uncertainty and the hovercraft trajectory tracking are simulated respectively to verify the effectiveness and the robustness of the proposed algorithm.

  3. Study of (2+1)-Dimensional Higher-Order Broer-Kaup System

    Institute of Scientific and Technical Information of China (English)

    WANG Ling; LIU Xi-Qiang; DONG Zhong-Zhou

    2007-01-01

    Painlevé property and infinite symmetries of the (2+1)-dimensional higher-order Broer-Kaup (HBK) system are studied in this paper.Using the modified direct method,we derive the theorem of general symmetry groups to (2+1)-dimensional HBK system.Based on our theorem,some new forms of solutions are obtained.We also find infinite number of conservation laws of the (2+1)-dimensional HBK system.

  4. Expressing First-Order π-Calculus in Higher-Order Calculus of Communicating Systems

    Institute of Scientific and Technical Information of China (English)

    Xian Xu

    2009-01-01

    In the study of process calculi, encoding between different calculi is an effective way to compare the expressive power of calculi and can shed light on the essence of where the difference lies. Thomsen and Sangiorgi have worked on the higher-order calculi (higher-order Calculus of Communicating Systems (CCS) and higher-order It-calculus, respectively) and the encoding from and to first-order π-calculus. However a fully abstract encoding of first-order π-calculus with higher-order CCS is not available up-today. This is what we intend to settle in this paper. We follow the encoding strategy, first proposed by Thomsen, of translating first-order π-calculus into Plain CHOCS. We show that the encoding strategy is fully abstract with respect to early bisimilarity (first-order π-calculus) and wired bisimilarity (Plain CHOCS) (which is a bisimulation defined on wired processes only sending and receiving wires), that is the core of the encoding strategy. Moreover from the fact that the wired bisimilarity is contained by the well-established context bisimilarity, we secure the soundness of the encoding, with respect to early bisimilarity and context bisimilarity. We use index technique to get around all the technical details to reach these main results of this paper. Finally, we make some discussion on our work and suggest some future work.

  5. Blowup results for the KGS system with higher order Yukawa coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Qi-Hong, E-mail: shiqh03@163.com [Department of Applied Mathematics, Lanzhou University of Technology, Lanzhou, Gansu 730050 (China); Li, Wan-Tong [School of Mathematics and Statistics, Lanzhou University, Lanzhou, Gansu 730000 (China); Wang, Shu [College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China)

    2015-10-15

    In this paper, we investigate the Klein-Gordon-Schrödinger (KGS) system with higher order Yukawa coupling in spatial dimensions N ≥ 3. We establish a perturbed virial type identity and prove blowup results relied on Lyapunov functionals for KGS system with a negative energy level. Additionally, we give a result with respect to the blowup rate in finite time for the radial solution in 3 spatial dimensions.

  6. Experimental characterization of a quantum many-body system via higher-order correlations.

    Science.gov (United States)

    Schweigler, Thomas; Kasper, Valentin; Erne, Sebastian; Mazets, Igor; Rauer, Bernhard; Cataldini, Federica; Langen, Tim; Gasenzer, Thomas; Berges, Jürgen; Schmiedmayer, Jörg

    2017-05-17

    Quantum systems can be characterized by their correlations. Higher-order (larger than second order) correlations, and the ways in which they can be decomposed into correlations of lower order, provide important information about the system, its structure, its interactions and its complexity. The measurement of such correlation functions is therefore an essential tool for reading, verifying and characterizing quantum simulations. Although higher-order correlation functions are frequently used in theoretical calculations, so far mainly correlations up to second order have been studied experimentally. Here we study a pair of tunnel-coupled one-dimensional atomic superfluids and characterize the corresponding quantum many-body problem by measuring correlation functions. We extract phase correlation functions up to tenth order from interference patterns and analyse whether, and under what conditions, these functions factorize into correlations of lower order. This analysis characterizes the essential features of our system, the relevant quasiparticles, their interactions and topologically distinct vacua. From our data we conclude that in thermal equilibrium our system can be seen as a quantum simulator of the sine-Gordon model, relevant for diverse disciplines ranging from particle physics to condensed matter. The measurement and evaluation of higher-order correlation functions can easily be generalized to other systems and to study correlations of any other observable such as density, spin and magnetization. It therefore represents a general method for analysing quantum many-body systems from experimental data.

  7. Distributed adaptive fuzzy iterative learning control of coordination problems for higher order multi-agent systems

    Science.gov (United States)

    Li, Jinsha; Li, Junmin

    2016-07-01

    In this paper, the adaptive fuzzy iterative learning control scheme is proposed for coordination problems of Mth order (M ≥ 2) distributed multi-agent systems. Every follower agent has a higher order integrator with unknown nonlinear dynamics and input disturbance. The dynamics of the leader are a higher order nonlinear systems and only available to a portion of the follower agents. With distributed initial state learning, the unified distributed protocols combined time-domain and iteration-domain adaptive laws guarantee that the follower agents track the leader uniformly on [0, T]. Then, the proposed algorithm extends to achieve the formation control. A numerical example and a multiple robotic system are provided to demonstrate the performance of the proposed approach.

  8. Instability and pattern formation in reaction-diffusion systems: a higher order analysis.

    Science.gov (United States)

    Riaz, Syed Shahed; Sharma, Rahul; Bhattacharyya, S P; Ray, D S

    2007-08-14

    We analyze the condition for instability and pattern formation in reaction-diffusion systems beyond the usual linear regime. The approach is based on taking into account perturbations of higher orders. Our analysis reveals that nonlinearity present in the system can be instrumental in determining the stability of a system, even to the extent of destabilizing one in a linearly stable parameter regime. The analysis is also successful to account for the observed effect of additive noise in modifying the instability threshold of a system. The analytical study is corroborated by numerical simulation in a standard reaction-diffusion system.

  9. The conormal derivative problem for higher order elliptic systems with irregular coefficients

    CERN Document Server

    Dong, Hongjie

    2012-01-01

    We prove $L_p$ estimates of solutions to a conormal derivative problem for divergence form complex-valued higher-order elliptic systems on a half space and on a Reifenberg flat domain. The leading coefficients are assumed to be merely measurable in one direction and have small mean oscillations in the orthogonal directions on each small ball. Our results are new even in the second-order case. The corresponding results for the Dirichlet problem were obtained recently in [15].

  10. Higher order elliptic and parabolic systems with variably partially BMO coefficients in regular and irregular domains

    CERN Document Server

    Dong, Hongjie

    2011-01-01

    The solvability in Sobolev spaces is proved for divergence form complex-valued higher order parabolic systems in the whole space, on a half space, and on a Reifenberg flat domain. The leading coefficients are assumed to be merely measurable in one spacial direction and have small mean oscillations in the orthogonal directions on each small cylinder. The directions in which the coefficients are only measurable vary depending on each cylinder. The corresponding elliptic problem is also considered.

  11. Tuning PID controllers for higher-order oscillatory systems with improved performance.

    Science.gov (United States)

    Malwatkar, G M; Sonawane, S H; Waghmare, L M

    2009-07-01

    In this paper, model based design of PID controllers is proposed for higher-order oscillatory systems. The proposed method has no limitations regarding systems order, time delays and oscillatory behavior. The reduced model is achieved based on third-order modeling and selection of coefficients through the use of frequency responses. The tuning of the PID parameters are obtained from a reduced third-order model; the procedure seems to be simple and effective, and improved performance of the overall system can be achieved. Three simulation examples and one real-time experiment are included to demonstrate the effectiveness and applicability of the proposed method to systems with oscillatory behavior.

  12. Design and implementation of components for a bioregenerative system for growing higher order plants in space

    Science.gov (United States)

    Brakman, B.; Dioso, L.; Parker, D.; Segal, L.; Merriman, C.; Howard, I.; Vu, H.; Anderson, K.; Riley, S.; Amery, D.

    1989-01-01

    This report summarizes the efforts of the NASA/USRA Advanced Design Program during the 1988-89 scholastic year. The primary goal was to address specific needs in the design of an integrated system to grow higher order plants in space. The initial phase of the design effort concentrated on studying such a system and identifying its needs. Once these needs were defined, emphasis was placed on the design and fabrication of devices to meet them. Specific attention was placed on a hand-held harvester, a nutrient concentration sensor, an air-water separator, and a closed-loop biological system simulation.

  13. Interaction Solutions for (1+1)-Dimensional Higher-Order Broer—Kaup System

    Science.gov (United States)

    Xin, Xiang-Peng; Liu, Xi-Qiang

    2016-11-01

    The (1+1)-dimensional higher-order Broer—Kaup (HBK) system is studied by consistent tanh expansion (CTE) method in this paper. It is proved that the HBK system is CTE solvable, and some exact interaction solutions among different nonlinear excitations such as solitons, rational waves, periodic waves, corresponding images are explicitly given. Supported by National Natural Science Foundation of China under Grant Nos. 11505090, 11171041, 11405103, 11447220, Research Award Foundation for Outstanding Young Scientists of Shandong Province under Grant No. BS2015SF009

  14. Verification of secure distributed systems in higher order logic: A modular approach using generic components

    Energy Technology Data Exchange (ETDEWEB)

    Alves-Foss, J.; Levitt, K.

    1991-01-01

    In this paper we present a generalization of McCullough's restrictiveness model as the basis for proving security properties about distributed system designs. We mechanize this generalization and an event-based model of computer systems in the HOL (Higher Order Logic) system to prove the composability of the model and several other properties about the model. We then develop a set of generalized classes of system components and show for which families of user views they satisfied the model. Using these classes we develop a collection of general system components that are instantiations of one of these classes and show that the instantiations also satisfied the security property. We then conclude with a sample distributed secure system, based on the Rushby and Randell distributed system design and designed using our collection of components, and show how our mechanized verification system can be used to verify such designs. 16 refs., 20 figs.

  15. Existence and Uniqueness of Solutions for Coupled Systems of Higher-Order Nonlinear Fractional Differential Equations

    Directory of Open Access Journals (Sweden)

    Ahmad Bashir

    2010-01-01

    Full Text Available We study an initial value problem for a coupled Caputo type nonlinear fractional differential system of higher order. As a first problem, the nonhomogeneous terms in the coupled fractional differential system depend on the fractional derivatives of lower orders only. Then the nonhomogeneous terms in the fractional differential system are allowed to depend on the unknown functions together with the fractional derivative of lower orders. Our method of analysis is based on the reduction of the given system to an equivalent system of integral equations. Applying the nonlinear alternative of Leray-Schauder, we prove the existence of solutions of the fractional differential system. The uniqueness of solutions of the fractional differential system is established by using the Banach contraction principle. An illustrative example is also presented.

  16. Undecidability Results for Bisimilarity on Prefix Rewrite Systems

    DEFF Research Database (Denmark)

    Jancar, Petr; Srba, Jiri

    2006-01-01

    We answer an open question related to bisimilarity checking on labelled transition systems generated by prefix rewrite rules on words. Stirling (1996, 1998) proved the decidability of bisimilarity for normed pushdown processes. This result was substantially extended by Senizergues (1998, 2005) wh...... of the form w -a-> R and R1 -a-> R2 and show when they yield low undecidability (Pi^0_1-completeness) and when high undecidability (Sigma^1_1-completeness), all with and without the assumption of normedness....

  17. Higher-order modulations of fs laser pulses for GHz frequency domain photon migration system.

    Science.gov (United States)

    Lin, Huang-Yi; Cheng, Nanyu; Tseng, Sheng-Hao; Chan, Ming-Che

    2014-02-24

    Except the fundamental modulation frequency, by higher-order-harmonic modulations of mode-locked laser pulses and a simple frequency demodulation circuit, a novel approach to GHz frequency-domain-photon-migration (FDPM) system was reported. With this novel approach, a wide-band modulation frequency comb is available without any external modulation devices and the only electronics to extract the optical attenuation and phase properties at a selected modulation frequency in FDPM systems are good mixers and lock-in devices. This approach greatly expands the frequency range that could be achieved by conventional FDPM systems and suggests that our system could extract much more information from biological tissues than the conventional FDPM systems. Moreover, this demonstration will be beneficial for discerning the minute change of tissue properties.

  18. A Rewritable, Random-Access DNA-Based Storage System

    Science.gov (United States)

    Tabatabaei Yazdi, S. M. Hossein; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

    2015-09-01

    We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.

  19. Transferring Instantly the State of Higher-Order Linear Descriptor (Regular Differential Systems Using Impulsive Inputs

    Directory of Open Access Journals (Sweden)

    Athanasios D. Karageorgos

    2009-01-01

    Full Text Available In many applications, and generally speaking in many dynamical differential systems, the problem of transferring the initial state of the system to a desired state in (almost zero-time time is desirable but difficult to achieve. Theoretically, this can be achieved by using a linear combination of Dirac -function and its derivatives. Obviously, such an input is physically unrealizable. However, we can think of it approximately as a combination of small pulses of very high magnitude and infinitely small duration. In this paper, the approximation process of the distributional behaviour of higher-order linear descriptor (regular differential systems is presented. Thus, new analytical formulae based on linear algebra methods and generalized inverses theory are provided. Our approach is quite general and some significant conditions are derived. Finally, a numerical example is presented and discussed.

  20. Higher Order Programming to Mine Knowledge for a Modern Medical Expert System

    CERN Document Server

    Kerdprasop, Nittaya

    2011-01-01

    Knowledge mining is the process of deriving new and useful knowledge from vast volumes of data and background knowledge. Modern healthcare organizations regularly generate huge amount of electronic data stored in the databases. These data are a valuable resource for mining useful knowledge to help medical practitioners making appropriate and accurate decision on the diagnosis and treatment of diseases. In this paper, we propose the design of a novel medical expert system based on a logic-programming framework. The proposed system includes a knowledge-mining component as a repertoire of tools for discovering useful knowledge. The implementation of classification and association mining tools based on the higher order and meta-level programming schemes using Prolog has been presented to express the power of logic-based language. Such language also provides a pattern matching facility, which is an essential function for the development of knowledge-intensive tasks. Besides the major goal of medical decision suppo...

  1. Nonexistence of solutions to systems of higher-order semilinear inequalities in cone-like domains

    Directory of Open Access Journals (Sweden)

    Abdallah El Hamidi

    2002-11-01

    Full Text Available In this paper, we obtain nonexistence results for global solutions to the system of higher-order semilinear partial differential inequalities $$displaylines{ frac{partial^k u_i}{partial t^k}-Delta (a_i (x,t u_i (x,t geq t^{gamma_{i+1}}|x|^{sigma_{i+1}} |u_{i+1} (x,t |^{p_{i+1}}, quad 1 leq i leq n, cr u_{n+1}=u_1, }$$ in cones and cone-like domains in $mathbb{R}^N$, $t>0$. Our results apply to nonnegative solutions and to solutions which change sign. Moreover, we provide a general formula of the critical exponent corresponding to this system. Our proofs are based on the test function method, developed by Mitidieri and Pohozaev.

  2. A higher-order numerical framework for stochastic simulation of chemical reaction systems.

    Science.gov (United States)

    Székely, Tamás; Burrage, Kevin; Erban, Radek; Zygalakis, Konstantinos C

    2012-07-15

    In this paper, we present a framework for improving the accuracy of fixed-step methods for Monte Carlo simulation of discrete stochastic chemical kinetics. Stochasticity is ubiquitous in many areas of cell biology, for example in gene regulation, biochemical cascades and cell-cell interaction. However most discrete stochastic simulation techniques are slow. We apply Richardson extrapolation to the moments of three fixed-step methods, the Euler, midpoint and θ-trapezoidal τ-leap methods, to demonstrate the power of stochastic extrapolation. The extrapolation framework can increase the order of convergence of any fixed-step discrete stochastic solver and is very easy to implement; the only condition for its use is knowledge of the appropriate terms of the global error expansion of the solver in terms of its stepsize. In practical terms, a higher-order method with a larger stepsize can achieve the same level of accuracy as a lower-order method with a smaller one, potentially reducing the computational time of the system. By obtaining a global error expansion for a general weak first-order method, we prove that extrapolation can increase the weak order of convergence for the moments of the Euler and the midpoint τ-leap methods, from one to two. This is supported by numerical simulations of several chemical systems of biological importance using the Euler, midpoint and θ-trapezoidal τ-leap methods. In almost all cases, extrapolation results in an improvement of accuracy. As in the case of ordinary and stochastic differential equations, extrapolation can be repeated to obtain even higher-order approximations. Extrapolation is a general framework for increasing the order of accuracy of any fixed-step stochastic solver. This enables the simulation of complicated systems in less time, allowing for more realistic biochemical problems to be solved.

  3. A higher-order numerical framework for stochastic simulation of chemical reaction systems.

    KAUST Repository

    Székely, Tamás

    2012-07-15

    BACKGROUND: In this paper, we present a framework for improving the accuracy of fixed-step methods for Monte Carlo simulation of discrete stochastic chemical kinetics. Stochasticity is ubiquitous in many areas of cell biology, for example in gene regulation, biochemical cascades and cell-cell interaction. However most discrete stochastic simulation techniques are slow. We apply Richardson extrapolation to the moments of three fixed-step methods, the Euler, midpoint and θ-trapezoidal τ-leap methods, to demonstrate the power of stochastic extrapolation. The extrapolation framework can increase the order of convergence of any fixed-step discrete stochastic solver and is very easy to implement; the only condition for its use is knowledge of the appropriate terms of the global error expansion of the solver in terms of its stepsize. In practical terms, a higher-order method with a larger stepsize can achieve the same level of accuracy as a lower-order method with a smaller one, potentially reducing the computational time of the system. RESULTS: By obtaining a global error expansion for a general weak first-order method, we prove that extrapolation can increase the weak order of convergence for the moments of the Euler and the midpoint τ-leap methods, from one to two. This is supported by numerical simulations of several chemical systems of biological importance using the Euler, midpoint and θ-trapezoidal τ-leap methods. In almost all cases, extrapolation results in an improvement of accuracy. As in the case of ordinary and stochastic differential equations, extrapolation can be repeated to obtain even higher-order approximations. CONCLUSIONS: Extrapolation is a general framework for increasing the order of accuracy of any fixed-step stochastic solver. This enables the simulation of complicated systems in less time, allowing for more realistic biochemical problems to be solved.

  4. Discrete sliding mode control for robust tracking of higher order delay time systems with experimental application.

    Science.gov (United States)

    Khandekar, A A; Malwatkar, G M; Patre, B M

    2013-01-01

    In this paper, a discrete time sliding mode controller (DSMC) is proposed for higher order plus delay time (HOPDT) processes. A sliding mode surface is selected as a function of system states and error and the tuning parameters of sliding mode controller are determined using dominant pole placement strategy. The condition for the existence of stable sliding mode is obtained by using Lyapunov function. The proposed method is applicable to HOPDT processes with oscillatory and integrating behavior, open loop instability or non-minimum phase characteristics and works satisfactory under the effect of parametric uncertainty. The method does not require reduced order model and provides simple way to design the controllers. The simulation and experimentation results show that the proposed method ensures desired tracking dynamics.

  5. Cluster synchrony in systems of coupled phase oscillators with higher-order coupling.

    Science.gov (United States)

    Skardal, Per Sebastian; Ott, Edward; Restrepo, Juan G

    2011-09-01

    We study the phenomenon of cluster synchrony that occurs in ensembles of coupled phase oscillators when higher-order modes dominate the coupling between oscillators. For the first time, we develop a complete analytic description of the dynamics in the limit of a large number of oscillators and use it to quantify the degree of cluster synchrony, cluster asymmetry, and switching. We use a variation of the recent dimensionality-reduction technique of Ott and Antonsen [Chaos 18, 037113 (2008)] and find an analytic description of the degree of cluster synchrony valid on a globally attracting manifold. Shaped by this manifold, there is an infinite family of steady-state distributions of oscillators, resulting in a high degree of multistability in the cluster asymmetry. We also show how through external forcing the degree of asymmetry can be controlled, and suggest that systems displaying cluster synchrony can be used to encode and store data.

  6. Sensitivity analysis of complex coupled systems extended to second and higher order derivatives

    Science.gov (United States)

    Sobieszczanski-Sobieski, Jaroslaw

    1989-01-01

    In design of engineering systems, the what if questions often arise such as: what will be the change of the aircraft payload, if the wing aspect ratio is incremented by 10 percent. Answers to such questions are commonly sought by incrementing the pertinent variable, and reevaluating the major disciplinary analyses involved. These analyses are contributed by engineering disciplines that are, usually, coupled, as are the aerodynamics, structures, and performance in the context of the question above. The what if questions can be answered precisely by computation of the derivatives. A method for calculation of the first derivatives has been developed previously. An algorithm is presented for calculation of the second and higher order derivatives.

  7. Cluster Synchrony in Systems of Coupled Phase Oscillators with Higher-Order Coupling

    CERN Document Server

    Skardal, Per Sebastian; Restrepo, Juan G

    2011-01-01

    We study the phenomenon of cluster synchrony that occurs in ensembles of coupled phase oscillators when higher-order modes dominate the coupling between oscillators. For the first time, we develop a complete analytic description of the dynamics in the limit of a large number of oscillators and use it to quantify the degree of cluster synchrony, cluster asymmetry, and switching. We use a variation of the recent dimensionality-reduction technique of Ott and Antonsen \\cite{OA1} and find an analytic description of the degree of cluster synchrony valid on a globally attracting manifold. Shaped by this manifold, there is an infinite family of steady-state distributions of oscillators, resulting in a high degree of multi-stability in the cluster asymmetry. We also show how through external forcing the degree of asymmetry can be controlled, and suggest that systems displaying cluster synchrony can be used to encode and store data.

  8. Impact of ligand protonation on higher-order metal complexation kinetics in aqueous systems.

    Science.gov (United States)

    Town, Raewyn M; Leeuwen, Herman P van

    2008-03-27

    The impact of ligand protonation on the complexation kinetics of higher-order complexes is quantitatively described. The theory is formulated on the basis of the usual situation for metal complex formation in aqueous systems in which the exchange of water for the ligand in the inner coordination sphere is rate-determining (Eigen mechanism). We derive expressions for the general case of lability of ML(n) species that account for the contributions from all outer-sphere complexes to the rate of complex formation. For dynamic complexes, dissociation of ML is usually the rate-determining step in the overall process ML(n) --> M. Under such conditions, it is the role of ligand protonation in the step ML --> M that is relevant for the kinetic flux. 1:2 complexes of Cd(II) with pyridine-2,6-dicarboxylic acid fall into this category, and their lability at a microelectrode is reasonably well predicted by the differentiated approach. For non-dynamic systems, the kinetic flux arising from dissociation of higher-order complexes contributes to the rate-determining step. In this case, the weighted contribution of protonated and unprotonated outer-sphere complexes in all contributing dissociation reactions must be taken into account. The kinetic flux arising from the dissociation of 1:2 complexes of Ni(II) with bicine at a conventional electrode was quite well described by this combined approach. The results establish the generic role of ligand protonation within the overall framework of metal complexation kinetics in which complexes may be dynamic to an extent that depends on the operational time scale of the measurement technique.

  9. Applied information system-based in enhancing students' understanding towards higher order thinking (HOTS)

    Science.gov (United States)

    Hua, Ang Kean; Ping, Owi Wei

    2017-05-01

    The application of information and communications technology (ICT) had become more important in our daily life, especially in educational field. Teachers are encouraged to use information system-based in teaching Mathematical courses. Higher Order Thinking Skills (HOTS) approach is unable to explain using chalk and talk methods. It needs students to analyze, evaluate, and create by their own natural abilities. The aim of this research study was to evaluate the effectiveness of the application information system-based in enhance the students understanding about HOTS question. Mixed-methods or quantitative and qualitative approach was applied in collecting data, which involve only the standard five students and the teachers in Sabak Bernam, Selangor. Pra-postests was held before and after using information system-based in teaching to evaluate the students' understanding. The result from post-test indicates significant improvement which proves that the use of information system based able to enhance students' understanding about HOTS question and solve it. There were several factor influenced the students such as students' attitude, teachers attraction, school facilities, and computer approach. Teachers play an important role in attracting students to learn. Therefore, the school should provide a conducive learning environment and good facilities for students to learn so that they are able to access more information and always exposed to new knowledge. As conclusion, information system-based are able to enhance students understanding the need of HOTS questions and solve it.

  10. Mechanizing Weakly Ground Termination Proving of Term Rewriting Systems by Structural and Cover-Set Inductions

    Institute of Scientific and Technical Information of China (English)

    Su Feng

    2005-01-01

    The paper presents three formal proving methods for generalized weakly ground terminating property, i.e.,weakly terminating property in a restricted domain of a term rewriting system, one with structural induction, one with cover-set induction, and the third without induction, and describes their mechanization based on a meta-computation model for term rewriting systems-dynamic term rewriting calculus. The methods can be applied to non-terminating, nonconfluent and/or non-left-linear term rewriting systems. They can do "forward proving" by applying propositions in the proof, as well as "backward proving" by discovering lemmas during the proof.

  11. Rogue waves in a resonant erbium-doped fiber system with higher-order effects

    CERN Document Server

    Zhang, Yu; He, Jingsong

    2015-01-01

    We mainly investigate a coupled system of the generalized nonlinear Schr\\"odinger equation and the Maxwell-Bloch equations which describes the wave propagation in an erbium-doped nonlinear fiber with higher-order effects including the forth-order dispersion and quintic non-Kerr nonlinearity. We derive the one-fold Darbox transformation of this system and construct the determinant representation of the $n$-fold Darboux transformation. Then the determinant representation of the $n$th new solutions $(E^{[n]},\\, p^{[n]},\\, \\eta^{[n]})$ which were generated from the known seed solutions $(E, \\, p, \\, \\eta)$ is established through the $n$-fold Darboux transformation. The solutions $(E^{[n]},\\, p^{[n]},\\, \\eta^{[n]})$ provide the bright and dark breather solutions of this system. Furthermore, we construct the determinant representation of the $n$th-order bright and dark rogue waves by Taylor expansions and also discuss the hybrid solutions which are the nonlinear superposition of the rogue wave and breather solution...

  12. Higher-Order Squeezing in a Boson Coupled Two-Mode System

    Science.gov (United States)

    Chizhov, A. V.; Haus, J. W.; Yeong, K. C.

    1996-01-01

    We consider a model for nondegenerate cavity fields interacting through an intervening Boson field. The quantum correlations introduced in this manner are manifest through their higher-order correlation functions where a type of squeezed state is identified.

  13. Wave train generation of solitons in systems with higher-order nonlinearities.

    Science.gov (United States)

    Mohamadou, Alidou; LatchioTiofack, C G; Kofané, Timoléon C

    2010-07-01

    Considering the higher-order nonlinearities in a material can significantly change its behavior. We suggest the extended nonlinear Schrödinger equation to describe the propagation of ultrashort optical pulses through a dispersive medium with higher-order nonlinearities. Soliton trains are generated through the modulational instability and we point out the influence of the septic nonlinearity in the modulational instability gain. Experimental values are used for the numerical simulations and the input plane wave leads to the development of pulse trains, depending upon the sign of the septic nonlinearity.

  14. Fluid-structure interaction simulations: efficient higher order time integration of partitioned systems

    NARCIS (Netherlands)

    van Zuijlen, A.H.

    2006-01-01

    The simulation of fluid-structure interaction can be a very time-consuming task due to the large amount of time steps that need to be taken in order to obtain an accurate solution. To reduce computing times a higher order time integration algorithm is applied. Based on a mixed combination of implici

  15. Higher-order differencing for phase-front propagation in geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Curtis; Pruess, Karsten

    1998-01-09

    We are testing higher-order differencing total variation diminishing schemes implemented in the reservoir simulator TOUGH2 to reduce numerical dispersion of phase fronts in geothermal flow problems. The schemes are called total variation diminishing because they employ flux limiters to prevent spurious oscillations that sometimes occur with other higher-order differencing schemes near sharp fronts. Thus it appears that total variation diminishing schemes rely on an implicit assumption that the overall variability of advected quantities stays constant or diminishes with time. We use the Leonard total variation diminishing scheme in two special problems designed to test the applicability of the scheme for cases where this implicit assumption is violated. In the first problem, we investigate the isothermal propagation of a phase front in a composite porous medium where phase saturation increases as the front enters the second medium. In the second problem, we investigate the propagation of a phase front where boiling increases the saturation difference across the front as it propagates. In the composite porous medium problem, we find that spurious phase saturations can arise if the weighting scheme is based on relative permeability; for weighting based on phase saturation, no such oscillation arises. In the boiling front propagation problem, the front position is highly sensitive to weighting scheme, and the Leonard total variation diminishing scheme is more accurate than upstream weighting because it decreases numerical dispersion in the thermal energy equation.

  16. Aggregation Kinetics of Higher-Order Fullerene Clusters in Aquatic Systems.

    Science.gov (United States)

    Aich, Nirupam; Boateng, Linkel K; Sabaraya, Indu Venu; Das, Dipesh; Flora, Joseph R V; Saleh, Navid B

    2016-04-05

    The aggregation kinetics of nC60 and higher-order fullerene (HOF) clusters, i.e., nC70, nC76, and nC84, was systematically studied under a wide range of mono- (NaCl) and divalent (CaCl2) electrolytes and using time-resolved dynamic light scattering. Suwanee River Humic Acid (SRHA) was also used to determine the effect of natural macromolecules on nHOF aggregation. An increase in electrolyte concentration resulted in electrical double-layer compression of the negatively charged fullerene clusters, and the nC60s and nHOFs alike displayed classical Derjaguin-Landau-Verwey-Overbeek (DLVO) type interaction. The critical coagulation concentration (CCC) displayed a strong negative correlation with the carbon number in fullerenes and was estimated as 220, 150, 100, and 70 mM NaCl and 10, 12, 6, and 7.5 mM CaCl2 for nC60, nC70, nC76, and nC84, respectively. The aggregation mechanism (i.e., van der Waals interaction domination) was enumerated via molecular dynamics simulation and modified DLVO model. The presence of SRHA (2.5 mg TOC/L) profoundly influenced the aggregation behavior by stabilizing all fullerene clusters, even at a 100 mM NaCl concentration. The results from this study can be utilized to predict aggregation kinetics of nHOF clusters other than the ones studied here. The scaling factor for van der Waals interaction can also be used to model nHOF cluster interaction.

  17. Solution Properties of Linear Descriptor (Singular Matrix Differential Systems of Higher Order with (Non- Consistent Initial Conditions

    Directory of Open Access Journals (Sweden)

    Athanasios A. Pantelous

    2010-01-01

    Full Text Available In some interesting applications in control and system theory, linear descriptor (singular matrix differential equations of higher order with time-invariant coefficients and (non- consistent initial conditions have been used. In this paper, we provide a study for the solution properties of a more general class of the Apostol-Kolodner-type equations with consistent and nonconsistent initial conditions.

  18. The next frontier of systems biology: higher-order and interspecies interactions.

    Science.gov (United States)

    Fischbach, Michael A; Krogan, Nevan J

    2010-01-01

    Systems approaches are not so different in essence from classical genetic and biochemical approaches, and in the future may become adopted so widely that the term 'systems biology' itself will become obsolete.

  19. Kosambi-Cartan-Chern (KCC) theory for higher-order dynamical systems

    Science.gov (United States)

    Harko, Tiberiu; Pantaragphong, Praiboon; Sabau, Sorin V.

    2016-12-01

    The Kosambi-Cartan-Chern (KCC) theory represents a powerful mathematical method for the investigation of the properties of dynamical systems. The KCC theory introduces a geometric description of the time evolution of a dynamical system, with the solution curves of the dynamical system described by methods inspired by the theory of geodesics in a Finsler spaces. The evolution of a dynamical system is geometrized by introducing a nonlinear connection, which allows the construction of the KCC covariant derivative, and of the deviation curvature tensor. In the KCC theory, the properties of any dynamical system are described in terms of five geometrical invariants, with the second one giving the Jacobi stability of the system. Usually, the KCC theory is formulated by reducing the dynamical evolution equations to a set of second-order differential equations. In this paper, we introduce and develop the KCC approach for dynamical systems described by systems of arbitrary n-dimensional first-order differential equations. We investigate in detail the properties of the n-dimensional autonomous dynamical systems, as well as the relationship between the linear stability and the Jacobi stability. As a main result we find that only even-dimensional dynamical systems can exhibit both Jacobi stability and instability behaviors, while odd-dimensional dynamical systems are always Jacobi unstable, no matter their Lyapunov stability. As applications of the developed formalism we consider the geometrization and the study of the Jacobi stability of the complex dynamical networks, and of the Λ-Cold Dark Matter (ΛCDM) cosmological models, respectively.

  20. Higher-order spin and charge dynamics in a quantum dot-lead hybrid system.

    Science.gov (United States)

    Otsuka, Tomohiro; Nakajima, Takashi; Delbecq, Matthieu R; Amaha, Shinichi; Yoneda, Jun; Takeda, Kenta; Allison, Giles; Stano, Peter; Noiri, Akito; Ito, Takumi; Loss, Daniel; Ludwig, Arne; Wieck, Andreas D; Tarucha, Seigo

    2017-09-22

    Understanding the dynamics of open quantum systems is important and challenging in basic physics and applications for quantum devices and quantum computing. Semiconductor quantum dots offer a good platform to explore the physics of open quantum systems because we can tune parameters including the coupling to the environment or leads. Here, we apply the fast single-shot measurement techniques from spin qubit experiments to explore the spin and charge dynamics due to tunnel coupling to a lead in a quantum dot-lead hybrid system. We experimentally observe both spin and charge time evolution via first- and second-order tunneling processes, and reveal the dynamics of the spin-flip through the intermediate state. These results enable and stimulate the exploration of spin dynamics in dot-lead hybrid systems, and may offer useful resources for spin manipulation and simulation of open quantum systems.

  1. A Formally Specified Type System and Operational Semantics for Higher-Order Procedural Variables

    CERN Document Server

    Crolard, Tristan

    2009-01-01

    We formally specified the type system and operational semantics of LOOPw with Ott and Isabelle/HOL proof assistant. Moreover, both the type system and the semantics of LOOPw have been tested using Isabelle/HOL program extraction facility for inductively defined relations. In particular, the program that computes the Ackermann function type checks and behaves as expected. The main difference (apart from the choice of an Ada-like concrete syntax) with LOOPw comes from the treatment of parameter passing. Indeed, since Ott does not currently fully support alpha-conversion, we rephrased the operational semantics with explicit aliasing in order to implement the out parameter passing mode.

  2. Tunneling in two-dimensional systems using a higher-order Herman-Kluk approximation.

    Science.gov (United States)

    Hochman, Gili; Kay, Kenneth G

    2009-02-14

    A principal weakness of the Herman-Kluk (HK) semiclassical approximation is its failure to provide a reliably accurate description of tunneling between different classically allowed regions. It was previously shown that semiclassical corrections significantly improve the HK treatment of tunneling for the particular case of the one-dimensional Eckart system. Calculations presented here demonstrate that the lowest-order correction also substantially improves the HK description of tunneling across barriers in two-dimensional systems. Numerical convergence issues either do not arise or are easily overcome, so that the calculations require only a moderate number of ordinary, real, classical trajectories.

  3. Continuity in weak topology:higher order linear systems of ODE

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We will introduce a type of Fredholm operators which are shown to have a certain con- tinuity in weak topologies.From this,we will prove that the fundamental matrix solutions of k-th, k≥2,order linear systems of ordinary differential equations are continuous in coefficient matrixes with weak topologies.Consequently,Floquet multipliers and Lyapunov exponents for periodic systems are continuous in weak topologies.Moreover,for the scalar Hill’s equations,Sturm-Liouville eigenvalues, periodic and anti-periodic eigenvalues,and rotation numbers are all continuous in potentials with weak topologies.These results will lead to many interesting variational problems.

  4. Transparent Higher Order Sliding Mode Control for Nonlinear Master-Slave Systems without Velocity Measurement

    Directory of Open Access Journals (Sweden)

    Luis G. Garcia-Valdovinos

    2015-04-01

    Full Text Available Transparency has been a major objective in bilateral teleoperation systems, even in the absence of time delay induced by the communication channel, since a high degree of transparency would allow humans to drive the remote teleoperator as if he or she were directly interacting with the remote environment, with the remote teleoperator as a physical and sensorial extension of the operator. When fast convergence of position and force tracking errors are ensured by the control system, then complete transparency is obtained, which would ideally guarantee humans to be tightly kinaesthetically coupled. In this paper a model-free Cartesian second order sliding mode (SOSM PD control scheme for nonlinear master-slave systems is presented. The proposed scheme does not rely on velocity measurements and attains very fast convergence of position trajectories, with bounded tracking of force trajectories, rendering a high degree of transparency with lesser knowledge of the system. The degree of transparency can easily be improved by tuning a feedback gain in the force loop. A unique energy storage function is introduced; such that a similar Cartesian-based controller is implemented in the master and slave sides. The resulting properties of the Cartesian control structure allows the human operator to input directly Cartesian variables, which makes clearer the kinaesthetic coupling, thus the proposed controller becomes a suitable candidate for practical implementation. The performance of the proposed scheme is evaluated in a semi-experimental setup.

  5. Effects of higher order control systems on aircraft approach and landing longitudinal handling qualities

    Science.gov (United States)

    Pasha, M. A.; Dazzo, J. J.; Silverthorn, J. T.

    1982-01-01

    An investigation of approach and landing longitudinal flying qualities, based on data generated using a variable stability NT-33 aircraft combined with significant control system dynamics is described. An optimum pilot lead time for pitch tracking, flight path angle tracking, and combined pitch and flight path angle tracking tasks is determined from a closed loop simulation using integral squared error (ISE) as a performance measure. Pilot gain and lead time were varied in the closed loop simulation of the pilot and aircraft to obtain the best performance for different control system configurations. The results lead to the selection of an optimum lead time using ISE as a performance criterion. Using this value of optimum lead time, a correlation is then found between pilot rating and performance with changes in the control system and in the aircraft dynamics. It is also shown that pilot rating is closely related to pilot workload which, in turn, is related to the amount of lead which the pilot must generate to obtain satisfactory response. The results also indicate that the pilot may use pitch angle tracking for the approach task and then add flight path angle tracking for the flare and touchdown.

  6. Effects of higher order control systems on aircraft approach and landing longitudinal handling qualities

    Science.gov (United States)

    Pasha, M. A.; Dazzo, J. J.; Silverthorn, J. T.

    1982-01-01

    An investigation of approach and landing longitudinal flying qualities, based on data generated using a variable stability NT-33 aircraft combined with significant control system dynamics is described. An optimum pilot lead time for pitch tracking, flight path angle tracking, and combined pitch and flight path angle tracking tasks is determined from a closed loop simulation using integral squared error (ISE) as a performance measure. Pilot gain and lead time were varied in the closed loop simulation of the pilot and aircraft to obtain the best performance for different control system configurations. The results lead to the selection of an optimum lead time using ISE as a performance criterion. Using this value of optimum lead time, a correlation is then found between pilot rating and performance with changes in the control system and in the aircraft dynamics. It is also shown that pilot rating is closely related to pilot workload which, in turn, is related to the amount of lead which the pilot must generate to obtain satisfactory response. The results also indicate that the pilot may use pitch angle tracking for the approach task and then add flight path angle tracking for the flare and touchdown.

  7. A New Look at Generalized Rewriting in Type Theory

    Directory of Open Access Journals (Sweden)

    Matthieu Sozeau

    2009-01-01

    Full Text Available Rewriting is an essential tool for computer-based reasoning, both automated and assisted. This is because rewriting is a general notion that permits modeling a wide range of problems and provides a means to effectively solve them. In a proof assistant, rewriting can be used to replace terms in arbitrary contexts, generalizing the usual equational reasoning to reasoning modulo arbitrary relations. This can be done provided the necessary proofs that functions appearing in goals are congruent with respect to specific relations. We present a new implementation of generalized rewriting in the Coq proof assistant, making essential use of the expressive power of dependent types and the recently implemented type class mechanism. The new rewrite tactic improves on and generalizes previous versions by natively supporting higher-order functions, polymorphism and subrelations. The type class system inspired by Haskell provides a perfect interface between the user and the tactic, making it easily extensible.

  8. Effects of higher order aberrations on beam shape in an optical recording system

    Science.gov (United States)

    Wang, Mark S.; Milster, Tom D.

    1992-01-01

    An unexpected irradiance pattern in the detector plane of an optical data storage system was observed. Through wavefront measurement and scalar diffraction modeling, it was discovered that the energy redistribution is due to residual third-order and fifth-order spherical aberration of the objective lens and cover-plate assembly. The amount of residual aberration is small, and the beam focused on the disk would be considered diffraction limited by several criteria. Since the detector is not in the focal plane, even this small amount of aberration has a significant effect on the energy distribution. We show that the energy redistribution can adversely affect focus error signals, which are responsible for maintaining sub-micron spot diameters on the spinning disk.

  9. Self-organizing approximation-based control for higher order systems.

    Science.gov (United States)

    Zhao, Yuanyuan; Farrell, Jay A

    2007-07-01

    Adaptive approximation-based control typically uses approximators with a predefined set of basis functions. Recently, spatially dependent methods have defined self-organizing approximators where new locally supported basis elements were incorporated when existing basis elements were insufficiently excited. In this paper, performance-dependent self-organizing approximators will be defined. The designer specifies a positive tracking error criteria. The self-organizing approximation-based controller then monitors the tracking performance and adds basis elements only as needed to achieve the tracking specification. The method of this paper is applicable to general nth-order input-state feedback linearizable systems. This paper includes a complete stability analysis and a detailed simulation example.

  10. Complimentary lower-level and higher-order systems underpin imitation learning.

    Science.gov (United States)

    Andrew, Matthew; Bennett, Simon J; Elliott, Digby; Hayes, Spencer J

    2016-04-01

    We examined whether the temporal representation developed during motor training with reduced-frequency knowledge of results (KR; feedback available on every other trial) was transferred to an imitation learning task. To this end, four groups first practised a three-segment motor sequence task with different KR protocols. Two experimental groups received reduced-frequency KR, one group received high-frequency KR (feedback available on every trial), and one received no-KR. Compared to the no-KR group, the groups that received KR learned the temporal goal of the movement sequence, as evidenced by increased accuracy and consistency across training. Next, all groups learned a single-segment movement that had the same temporal goal as the motor sequence task but required the imitation of biological and nonbiological motion kinematics. Kinematic data showed that whilst all groups imitated biological motion kinematics, the two experimental reduced-frequency KR groups were on average ∼ 800 ms more accurate at imitating movement time than the high-frequency KR and no-KR groups. The interplay between learning biological motion kinematics and the transfer of temporal representation indicates imitation involves distinct, but complementary lower-level sensorimotor and higher-level cognitive processing systems. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  11. Beyond the Förster theory of excitation energy transfer: importance of higher-order processes in supramolecular antenna systems.

    Science.gov (United States)

    May, Volkhard

    2009-12-07

    Electronic excitation energy transfer in molecular systems is connected with the de-excitation of one molecule and the excitation of the other. Mostly, it can be understood in terms of Förster (or fluorescence) resonance energy transfer. An increasing interest in the optimization of artificial light harvesting systems, however, requires a more detailed study going beyond the standard Förster scheme. There are two main routes to do this. Considering a Coulombic less-strongly coupled system first, coherences among different chromophores may be considered in the framework of perturbation theory with higher-order mechanisms correcting the standard second-order description. Secondly, if inter-chromophore coherences are dominant and delocalized Frenkel-exciton states are formed, it becomes of some importance to study their decay due to the coupling to vibrational degrees of freedom. While we will also comment on this latter mechanism, the first description based on localized excitations will be the main focus. A general higher-order theory resulting in respective transition rates and rate equations is utilized. Its capability is demonstrated when presenting a systematic description of short-range and long-range corrections to the basic Förster mechanism. Accordingly, a unique description of bridge-mediated and photon-mediated long-range electronic excitation energy transfer is offered. Moreover, short-range excitation energy transfer appearing as a two electron exchange is also discussed. And, the exciton-exciton annihilation process present at higher optical excitation intensities is described as a direct higher-order transition. The related higher-order vibrational correlation functions are presented and estimated for the reference case where the coupling to vibrational degrees of freedom either of intra-molecular or inter-molecular type is reduced to a simple electronic state dephasing process.

  12. Composite Backstepping Consensus Algorithms of Leader-Follower Higher-Order Nonlinear Multiagent Systems Subject to Mismatched Disturbances.

    Science.gov (United States)

    Wang, Xiangyu; Li, Shihua; Chen, Michael Z Q

    2017-07-27

    This paper is devoted to solving the output consensus problem of leader-follower higher-order nonlinear multiagent systems subject to mismatched disturbances. The disturbances are allowed to be in higher-order forms. First, by constructing a generalized proportional-integral observer for each follower, estimates of the disturbances and their derivatives are obtained. At the same time, a distributed observer is also developed for the followers to estimate the leader state information. Second, based on the estimates of the disturbances and the leader state, together with the backstepping technique, a feedforward-feedback composite consensus control scheme is proposed. The designed distributed protocols guarantee asymptotic output consensus for the agents. Simulation results validate the effectiveness of the proposed composite control scheme.

  13. Higher order aberrations comparison in fellow eyes following intraLase LASIK with wavelight allegretto and customcornea LADArvision4000 systems.

    Science.gov (United States)

    Tran, Dan B; Shah, Viraj

    2006-11-01

    To compare the differences in objective and subjective visual outcomes with wavefront-optimized versus wavefront-guided excimer laser ablations using two different excimer laser platforms. In this prospective, randomized, matched, contralateral eye study, one eye was treated with the Alcon CustomCornea system, and the fellow eye was treated with the WaveLight Allegretto Wavefront-Optimized system. The IntraLase FS30 femtosecond laser was used to create all flaps. Treatments were randomized to the dominant eye, and optical treatment zones were matched to 6.5 mm. Patients were observed for 3 months after surgery. Initial data analysis was available for the first 28 eyes of 14 patients. The only statistically significant differences between the groups were seen in the amount of higher order aberrations-the 14 eyes in the WaveLight group had a mean preoperative root-mean-square (RMS) error of 0.37 microm compared to 0.36 microm for 14 eyes in the Alcon group. Of the 8 patients who had 3-month follow-up, 8 eyes in the WaveLight group had a mean RMS error of 0.58 microm at 3 months, compared to 0.41 microm in the 8 eyes in the Alcon group. Early results from this study have shown that both laser platforms produce accurate refractive outcomes; however, the Alcon CustomCornea LADARVision4000 system induces statistically significantly fewer higher order aberrations than the WaveLight Allegretto system.

  14. Continuous higher-order sliding mode control with time-varying gain for a class of uncertain nonlinear systems.

    Science.gov (United States)

    Han, Yaozhen; Liu, Xiangjie

    2016-05-01

    This paper presents a continuous higher-order sliding mode (HOSM) control scheme with time-varying gain for a class of uncertain nonlinear systems. The proposed controller is derived from the concept of geometric homogeneity and super-twisting algorithm, and includes two parts, the first part of which achieves smooth finite time stabilization of pure integrator chains. The second part conquers the twice differentiable uncertainty and realizes system robustness by employing super-twisting algorithm. Particularly, time-varying switching control gain is constructed to reduce the switching control action magnitude to the minimum possible value while keeping the property of finite time convergence. Examples concerning the perturbed triple integrator chains and excitation control for single-machine infinite bus power system are simulated respectively to demonstrate the effectiveness and applicability of the proposed approach.

  15. Higher Order Spreading Models

    CERN Document Server

    Argyros, S A; Tyros, K

    2012-01-01

    We introduce the higher order spreading models associated to a Banach space $X$. Their definition is based on $\\ff$-sequences $(x_s)_{s\\in\\ff}$ with $\\ff$ a regular thin family and the plegma families. We show that the higher order spreading models of a Banach space $X$ form an increasing transfinite hierarchy $(\\mathcal{SM}_\\xi(X))_{\\xi<\\omega_1}$. Each $\\mathcal{SM}_\\xi (X)$ contains all spreading models generated by $\\ff$-sequences $(x_s)_{s\\in\\ff}$ with order of $\\ff$ equal to $\\xi$. We also provide a study of the fundamental properties of the hierarchy.

  16. Scaffolded Writing and Rewriting in the Discipline: A Web-Based Reciprocal Peer Review System

    Science.gov (United States)

    Cho, Kwangsu; Schunn, Christian D.

    2007-01-01

    This paper describes how SWoRD (scaffolded writing and rewriting in the discipline), a web-based reciprocal peer review system, supports writing practice, particularly for large content courses in which writing is considered critical but not feasibly included. To help students gain content knowledge as well as writing and reviewing skills, SWoRD…

  17. Some Results on the Confluence Property of Combined Term Rewriting Systems

    Institute of Scientific and Technical Information of China (English)

    张旭波

    1991-01-01

    Generally speaking,confluence property is not preserved when Term Rewriting Systems (TRSs) are combined,even if they are canonical.In this paper we give some sufficient conditions for ensuring the confluence property of combined left-linear,overlapping TRSs.

  18. Design of Fuzzy Functional Observer-Controller via Higher Order Derivatives of Lyapunov Function for Nonlinear Systems.

    Science.gov (United States)

    Liu, Chuang; Lam, Hak-Keung; Fernando, Tyrone; Iu, Herbert Ho-Ching

    2016-05-02

    In this paper, we investigate the stability of Takagi-Sugeno fuzzy-model-based (FMB) functional observer-control system. When system states are not measurable for state-feedback control, a fuzzy functional observer is designed to directly estimate the control input instead of the system states. Although the fuzzy functional observer can reduce the order of the observer, it leads to a number of observer gains to be determined. Therefore, a new form of fuzzy functional observer is proposed to facilitate the stability analysis such that the observer gains can be numerically obtained and the stability can be guaranteed simultaneously. The proposed form is also in favor of applying separation principle to separately design the fuzzy controller and the fuzzy functional observer. To design the fuzzy controller with the consideration of system stability, higher order derivatives of Lyapunov function (HODLF) are employed to reduce the conservativeness of stability conditions. The HODLF generalizes the commonly used first-order derivative. By exploiting the properties of membership functions and the dynamics of the FMB control system, convex and relaxed stability conditions can be derived. Simulation examples are provided to show the relaxation of the proposed stability conditions and the feasibility of designed fuzzy functional observer-controller.

  19. Higher-Order Hierarchies

    DEFF Research Database (Denmark)

    Ernst, Erik

    2003-01-01

    . Finally, it must be possible to write generic code that works on every hierarchy derived from the hierarchy for which it was written. This paper presents a language design that supports such a notion of higher-order hierarchies. It has been implemented in context of a full-fledged, statically typed...... be possible to create hierarchies incrementally based on existing hierarchies, such that commonalities are expressed via reuse, not duplication. Second, the hierarchies must themselves be organized into hierarchies, such that their relationships are made explicit and can be exploited in a type safe manner...... language....

  20. When sounds become actions: higher-order representation of newly learned action sounds in the human motor system.

    Science.gov (United States)

    Ticini, Luca F; Schütz-Bosbach, Simone; Weiss, Carmen; Casile, Antonino; Waszak, Florian

    2012-02-01

    In the absence of visual information, our brain is able to recognize the actions of others by representing their sounds as a motor event. Previous studies have provided evidence for a somatotopic activation of the listener's motor cortex during perception of the sound of highly familiar motor acts. The present experiments studied (a) how the motor system is activated by action-related sounds that are newly acquired and (b) whether these sounds are represented with reference to extrinsic features related to action goals rather than with respect to lower-level intrinsic parameters related to the specific movements. TMS was used to measure the correspondence between auditory and motor codes in the listener's motor system. We compared the corticomotor excitability in response to the presentation of auditory stimuli void of previous motor meaning before and after a short training period in which these stimuli were associated with voluntary actions. Novel cross-modal representations became manifest very rapidly. By disentangling the representation of the muscle from that of the action's goal, we further showed that passive listening to newly learnt action-related sounds activated a precise motor representation that depended on the variable contexts to which the individual was exposed during testing. Our results suggest that the human brain embodies a higher-order audio-visuo-motor representation of perceived actions, which is muscle-independent and corresponds to the goals of the action.

  1. Introducing nonlinear, multivariate 'Predictor Surfaces' for quantitative modeling of chemical systems with higher-order, coupled predictor variables.

    Science.gov (United States)

    Horton, Rebecca B; McConico, Morgan; Landry, Currie; Tran, Tho; Vogt, Frank

    2012-10-09

    Innovations in chemometrics are required for studies of chemical systems which are governed by nonlinear responses to chemical parameters and/or interdependencies (coupling) among these parameters. Conventional and linear multivariate models have limited use for quantitative and qualitative investigations of such systems because they are based on the assumption that the measured data are simple superpositions of several input parameters. 'Predictor Surfaces' were developed for studies of more chemically complex systems such as biological materials in order to ensure accurate quantitative analyses and proper chemical modeling for in-depth studies of such systems. Predictor Surfaces are based on approximating nonlinear multivariate model functions by multivariate Taylor expansions which inherently introduce the required coupled and higher-order predictor variables. As proof-of-principle for the Predictor Surfaces' capabilities, an application from environmental analytical chemistry was chosen. Microalgae cells are known to sensitively adapt to changes in environmental parameters such as pollution and/or nutrient availability and thus have potential as novel in situ sensors for environmental monitoring. These adaptations of the microalgae cells are reflected in their chemical signatures which were then acquired by means of FT-IR spectroscopy. In this study, the concentrations of three nutrients, namely inorganic carbon and two nitrogen containing ions, were chosen. Biological considerations predict that changes in nutrient availability produce a nonlinear response in the cells' biomass composition; it is also known that microalgae need certain nutrient mixes to thrive. The nonlinear Predictor Surfaces were demonstrated to be more accurate in predicting the values of these nutrients' concentrations than principal component regression. For qualitative chemical studies of biological systems, the Predictor Surfaces themselves are a novel tool as they visualize

  2. Higher order mode optical fiber Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Friis, Søren Michael Mørk; Usuga Castaneda, Mario A.

    2016-01-01

    We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations.......We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations....

  3. Automatic micropropagation of plants--the vision-system: graph rewriting as pattern recognition

    Science.gov (United States)

    Schwanke, Joerg; Megnet, Roland; Jensch, Peter F.

    1993-03-01

    The automation of plant-micropropagation is necessary to produce high amounts of biomass. Plants have to be dissected on particular cutting-points. A vision-system is needed for the recognition of the cutting-points on the plants. With this background, this contribution is directed to the underlying formalism to determine cutting-points on abstract-plant models. We show the usefulness of pattern recognition by graph-rewriting along with some examples in this context.

  4. The Tutte-Grothendieck group of a convergent alphabetic rewriting system

    CERN Document Server

    Poinsot, Laurent

    2011-01-01

    The two operations, deletion and contraction of an edge, on multigraphs directly lead to the Tutte polynomial which satisfies a universal problem. As observed by Brylawski in terms of order relations, these operations may be interpreted as a particular instance of a general theory which involves universal invariants like the Tutte polynomial, and a universal group, called the Tutte-Grothendieck group. In this contribution, Brylawski's theory is extended in two ways: first of all, the order relation is replaced by a string rewriting system, and secondly, commutativity by partial commutations (that permits a kind of interpolation between non commutativity and full commutativity). This allows us to clarify the relations between the semigroup subject to rewriting and the Tutte-Grothendieck group: the later is actually the Grothendieck group completion of the former, up to the free adjunction of a unit (this was even not mention by Brylawski), and normal forms may be seen as universal invariants. Moreover we prove...

  5. Symbolic rewriting techniques

    CERN Document Server

    Weispfenning, Volker; Grabmeier, Johannes

    1998-01-01

    Symbolic rewriting techniques are methods for deriving consequences from systems of equations, and are of great use when investigating the structure of the solutions. Such techniques appear in many important areas of research within computer algebra: • the Knuth-Bendix completion for groups, monoids and general term-rewriting systems, • the Buchberger algorithm for Gröbner bases, • the Ritt-Wu characteristic set method for ordinary differential equations, and • the Riquier-Janet method for partial differential equations. This volume contains invited and contributed papers to the Symbolic Rewriting Techniques workshop, which was held at the Centro Stefano Franscini in Ascona, Switzerland, from April 30 to May 4, 1995. That workshop brought together 40 researchers from various areas of rewriting techniques, the main goal being the investigation of common threads and methods. Following the workshops, each contribution was formally refereed and 14 papers were selected for publication.

  6. P systems with array objects and array rewriting rules

    Institute of Scientific and Technical Information of China (English)

    K.G. Subramanian; R. Saravanan; M. Geethalakshmi; P. Helen Chandra; M. Margenstern

    2007-01-01

    Array P systems were introduced by Pǎun Gh. which is linking the two areas of membrane computing and picture grammars. Puzzle grammars were introduced by us for generating connected picture arrays in the two-dimensional plane, motivated by the problem of tiling the plane. On the other hand, incorporating into arrays the developmental type of generation used in the well-known biologically motivated L systems, Siromoney and Siromoney proposed a very general rectangular array generating model, called extended controlled tabled L array system (ECTLAS). In this paper we introduce two variations of the array P system, called BPG array P system and parallel array P system. The former has in the regions array objects and basic puzzle grammar rules (BPG), which are a specific kind of puzzle grammar rules. In the latter, the regions have rectangular array objects and tables of context-free rules. We examine these two types of P systems for their array generative power.

  7. Rewriting Modulo SMT

    Science.gov (United States)

    Rocha, Camilo; Meseguer, Jose; Munoz, Cesar A.

    2013-01-01

    Combining symbolic techniques such as: (i) SMT solving, (ii) rewriting modulo theories, and (iii) model checking can enable the analysis of infinite-state systems outside the scope of each such technique. This paper proposes rewriting modulo SMT as a new technique combining the powers of (i)-(iii) and ideally suited to model and analyze infinite-state open systems; that is, systems that interact with a non-deterministic environment. Such systems exhibit both internal non-determinism due to the system, and external non-determinism due to the environment. They are not amenable to finite-state model checking analysis because they typically are infinite-state. By being reducible to standard rewriting using reflective techniques, rewriting modulo SMT can both naturally model and analyze open systems without requiring any changes to rewriting-based reachability analysis techniques for closed systems. This is illustrated by the analysis of a real-time system beyond the scope of timed automata methods.

  8. Comparison of the FFT/matrix inversion and system matrix techniques for higher-order probe correction in spherical near-field antenna measurements

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Nielsen, Jeppe Majlund; Breinbjerg, Olav

    2011-01-01

    Two higher-order probe-correction techniques for spherical near-field antenna measurements are compared in details for the accuracy they provide and their computational cost. The investigated techniques are the FFT/matrix inversion and the system matrix inversion. Each of these techniques allows...... and a higher-order probe....... correction of general high-order probes, including non-symmetric dual-polarized antennas with independent ports. The investigation was carried out by processing with each technique the same measurement data for a challenging case with an antenna under test significantly offset from the center of rotation...

  9. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. II. Consideration for higher order terms.

    Science.gov (United States)

    O'Brien, Daniel B; Massari, Aaron M

    2015-01-14

    The generalized optical interference model for interfacial contributions to vibrational sum frequency generation (VSFG) spectroscopic signals from organic thin film systems is extended to include a description of optical interferences contained in the thin film bulk response. This is based on electric quadrupolar interactions with the input fields and includes a discussion on possible contribution from the electric quadrupolar polarization. VSFG data from the first of this two part report are analyzed and include effects from higher order responses, for both bulk and higher order interfacial terms. The results indicate that although it is capable of capturing many of the data features, the electric dipole treatment is likely not a complete description of the VSFG intensity data from this system. An analysis based on the signs of the resulting response amplitudes is used to deduce the relative magnitude of the electric dipole and higher order interfacial terms. It is found that the buried interface is closer to satisfying the electric dipole approximation, consistent with smaller field gradients due to closer index matching between the organic thin film and substrate relative to air. The procedure outlined in this work allows for the difficult task of deducing a physical picture of average molecular orientation at the buried interface of a multilayer organic thin film system while including higher order effects.

  10. PHASE EQUILIBRIA INVESTIGATION OF BINARY, TERNARY, AND HIGHER ORDER SYSTEMS. PART 9. CALCULATION OF THERMODYNAMIC QUANTITIES FROM PHASE DIAGRAMS

    Science.gov (United States)

    The thermodynamic fundamentals relating phase equilibria in binary and ternary systems to the thermodynamic properties of the phases are reviewed and...system demonstrate the application of the equations for extracting thermodynamic data from phase diagrams and also for the prediction of phase equilibria .

  11. General coalescence conditions for the exact wave functions: higher-order relations for two-particle systems.

    Science.gov (United States)

    Kurokawa, Yusaku I; Nakashima, Hiroyuki; Nakatsuji, Hiroshi

    2013-07-28

    We derived the necessary conditions that the non-relativistic time-independent exact wave functions for two-particle systems must satisfy at a coalescence (or cusp) point. Some of such necessary conditions are already known to be Kato's cusp condition (CC) and Rassolov and Chipman's CC. In the present study, we extended and generalized those conditions, calling them generalized coalescence conditions (GCCs). Kato's CC and Rassolov and Chipman's CC were shown to be specific cases included in the GCCs. The GCCs can be applied not only to Coulombic systems but also to any systems where the interaction between two particles is represented in a power series of the inter-particle distance. We confirmed the correctness of our derivation of these GCCs by applying the free complement wave functions of a hydrogen atom in ground and excited states, a harmonic oscillator, and a system with an interacting potential of V = r.

  12. Engineering sciences design. Design and implementation of components for a bioregenerative system for growing higher order plants in space

    Science.gov (United States)

    Nevill, Gale E., Jr.

    1989-01-01

    The primary goal was to address specific needs in the design of an integrated system to grow higher plants in space. With the needs defined, the emphasis was placed on the design and fabrication of devices to meet these needs. Specific attention was placed on a hand-held harvester, a nutrient concentration sensor, an air-water separator, and a closed-loop biological system simulation.

  13. General coalescence conditions for the exact wave functions. II. Higher-order relations for many-particle systems.

    Science.gov (United States)

    Kurokawa, Yusaku I; Nakashima, Hiroyuki; Nakatsuji, Hiroshi

    2014-06-07

    We derived the necessary conditions that must be satisfied by the non-relativistic time-independent exact wave functions for many-particle systems at a two-particle coalescence (or cusp) point. Some simple conditions are known to be Kato's cusp condition (CC) and Rassolov and Chipman's CC. In a previous study, we derived an infinite number of necessary conditions that two-particle wave functions must satisfy at a coalescence point. In the present study, we extend these conditions to many-particle systems. They are called general coalescence conditions (GCCs), and Kato's CC and Rassolov and Chipman's CC are included as special conditions. GCCs can be applied not only to Coulombic systems but also to any system in which the interaction between two particles is represented in a power series of inter-particle distances. We confirmed the correctness of our derivation of the GCCs by applying the exact wave function of a harmonium in electron-electron and electron-nucleus coalescence situations. In addition, we applied the free complement (FC) wave functions of a helium atom to the GCCs to examine the accuracy of the FC wave function in the context of a coalescence situation.

  14. Promoting Higher Order Thinking Skills via IPTEACES e-Learning Framework in the Learning of Information Systems Units

    Science.gov (United States)

    Isaias, Pedro; Issa, Tomayess; Pena, Nuno

    2014-01-01

    When developing and working with various types of devices from a supercomputer to an iPod Mini, it is essential to consider the issues of Human Computer Interaction (HCI) and Usability. Developers and designers must incorporate HCI, Usability and user satisfaction in their design plans to ensure that systems are easy to learn, effective,…

  15. General coalescence conditions for the exact wave functions. II. Higher-order relations for many-particle systems

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, Yusaku I., E-mail: y-kurokawa@qcri.or.jp, E-mail: h.nakatsuji@qcri.or.jp; Nakashima, Hiroyuki; Nakatsuji, Hiroshi, E-mail: y-kurokawa@qcri.or.jp, E-mail: h.nakatsuji@qcri.or.jp [Quantum Chemistry Research Institute, Kyodai Katsura Venture Plaza 107, Goryo Oohara 1-36, Nishikyo-ku, Kyoto 615-8245 (Japan)

    2014-06-07

    We derived the necessary conditions that must be satisfied by the non-relativistic time-independent exact wave functions for many-particle systems at a two-particle coalescence (or cusp) point. Some simple conditions are known to be Kato's cusp condition (CC) and Rassolov and Chipman's CC. In a previous study, we derived an infinite number of necessary conditions that two-particle wave functions must satisfy at a coalescence point. In the present study, we extend these conditions to many-particle systems. They are called general coalescence conditions (GCCs), and Kato's CC and Rassolov and Chipman's CC are included as special conditions. GCCs can be applied not only to Coulombic systems but also to any system in which the interaction between two particles is represented in a power series of inter-particle distances. We confirmed the correctness of our derivation of the GCCs by applying the exact wave function of a harmonium in electron-electron and electron-nucleus coalescence situations. In addition, we applied the free complement (FC) wave functions of a helium atom to the GCCs to examine the accuracy of the FC wave function in the context of a coalescence situation.

  16. EXPERIMENTAL PHASE EQUILIBRIA OF SELECTED BINARY, TERNARY, AND HIGHER ORDER SYSTEMS. PART 4. THE PHASE DIAGRAM W-B-C

    Science.gov (United States)

    system and the mutual solubilities between carbide and boride phases are small. The solid state sections (򒾐C) are characterized by two- phase ... equilibria existing between the phase pairs W2B + W2C, W2B + WC, WC + WB, WB + C, W2B5 + C, W2B5 + B4C, and WB approximately 4 + B4C. The two-phase

  17. Modeling Dynamic Programming Problems over Sequences and Trees with Inverse Coupled Rewrite Systems

    Directory of Open Access Journals (Sweden)

    Robert Giegerich

    2014-03-01

    Full Text Available Dynamic programming is a classical algorithmic paradigm, which often allows the evaluation of a search space of exponential size in polynomial time. Recursive problem decomposition, tabulation of intermediate results for re-use, and Bellman’s Principle of Optimality are its well-understood ingredients. However, algorithms often lack abstraction and are difficult to implement, tedious to debug, and delicate to modify. The present article proposes a generic framework for specifying dynamic programming problems. This framework can handle all kinds of sequential inputs, as well as tree-structured data. Biosequence analysis, document processing, molecular structure analysis, comparison of objects assembled in a hierarchic fashion, and generally, all domains come under consideration where strings and ordered, rooted trees serve as natural data representations. The new approach introduces inverse coupled rewrite systems. They describe the solutions of combinatorial optimization problems as the inverse image of a term rewrite relation that reduces problem solutions to problem inputs. This specification leads to concise yet translucent specifications of dynamic programming algorithms. Their actual implementation may be challenging, but eventually, as we hope, it can be produced automatically. The present article demonstrates the scope of this new approach by describing a diverse set of dynamic programming problems which arise in the domain of computational biology, with examples in biosequence and molecular structure analysis.

  18. Binary decision diagrams by shared rewriting

    NARCIS (Netherlands)

    Pol, J. van de; Zantema, H.

    2000-01-01

    BDDs provide an established technique for propositional formula manipulation. In this paper we re-develope the basic BDD theory using standard rewriting techniques. Since a BDD is a DAG instead of a tree we need a notion of shared rewriting and develope appropriate theory. A rewriting system is

  19. Exploring eclipsing binaries, triples and higher-order multiple star systems with the SuperWASP archive

    CERN Document Server

    Lohr, M E

    2015-01-01

    The Super Wide Angle Search for Planets (SuperWASP) is a whole-sky high-cadence optical survey which has searched for exoplanetary transit signatures since 2004. Its archive contains long-term light curves for ~30 million 8-15 V magnitude stars, making it a valuable serendipitous resource for variable star research. We have concentrated on the evidence it provides for eclipsing binaries, in particular those exhibiting orbital period variations, and have developed custom tools to measure periods precisely and detect period changes reliably. Amongst our results are: a collection of 143 candidate contact or semi-detached eclipsing binaries near the short-period limit in the main sequence binary period distribution; a probable hierarchical triple exhibiting dramatic sinusoidal period variations; a new doubly-eclipsing quintuple system; and new evidence for period change or stability in 12 post-common-envelope eclipsing binaries, which may support the existence of circumbinary planets in such systems. A large-scal...

  20. Measuring violations of general relativity from single gravitational wave detection by nonspinning binary systems: Higher-order asymptotic analysis

    Science.gov (United States)

    Tso, Rhondale; Zanolin, Michele

    2016-06-01

    A frequentist asymptotic expansion method for error estimation is employed for a network of gravitational wave detectors to assess the amount of information that can be extracted from gravitational wave observations. Mathematically we derive lower bounds in the errors that any parameter estimator will have in the absence of prior knowledge to distinguish between the post-Einsteinian (ppE) description of coalescing binary systems and that of general relativity. When such errors are smaller than the parameter value, there is a possibility to detect these violations from general relativity (GR). A parameter space with inclusion of dominant dephasing ppE parameters (β ,b ) is used for a study of first- and second-order (co)variance expansions, focusing on the inspiral stage of a nonspinning binary system of zero eccentricity detectible through Advanced LIGO and Advanced Virgo. Our procedure is an improvement of the Cramér-Rao lower bound. When Bayesian errors are lower than our bound it means that they depend critically on the priors. The analysis indicates the possibility of constraining deviations from GR in inspiral signal-to-noise ratio (SNR) (ρ ˜15 - 17 ) regimes that are achievable in upcoming scientific runs (GW150914 had an inspiral SNR ˜12 ). The errors on β also increase errors of other parameters such as the chirp mass M and symmetric mass ratio η . Application is done to existing alternative theories of gravity, which include modified dispersion relation of the waveform; nonspinning models of quadratic modified gravity; and dipole gravitational radiation (i.e., Brans-Dicke-type) modifications.

  1. Correspondence between neutron depolarization and higher order magnetic susceptibility to investigate ferromagnetic clusters in phase separated systems.

    Science.gov (United States)

    Manna, Kaustuv; Samal, D; Bera, A K; Elizabeth, Suja; Yusuf, S M; Kumar, P S Anil

    2014-01-08

    It is a tough task to distinguish a short-range ferromagnetically correlated cluster-glass phase from a canonical spin-glass-like phase in many magnetic oxide systems using conventional magnetometry measurements. As a case study, we investigate the magnetic ground state of La0.85Sr0.15CoO3, which is often debated based on phase separation issues. We report the results of two samples of La0.85Sr0.15CoO3 (S-1 and S-2) prepared under different conditions. Neutron depolarization, higher harmonic ac susceptibility and magnetic relaxation studies were carried out along with conventional magnetometry measurements to differentiate subtle changes at the microscopic level. There is no evidence of ferromagnetic correlation in the sample S-2 attributed to a spin-glass phase, and this is compounded by the lack of existence of a second order component of higher harmonic ac susceptibility and neutron depolarization. A magnetic relaxation experiment at different temperatures complements the spin glass characteristic in S-2. All these signal a sharp variance when we consider the cluster-glass-like phase (phase separated) in S-1, especially when prepared from an improper chemical synthesis process. This shows that the nonlinear ac susceptibility is a viable tool to detect ferromagnetic clusters such as those the neutron depolarization study can reveal.

  2. Higher order expansions for the entropy of a dimer or a monomer-dimer system on d-dimensional lattices

    CERN Document Server

    Butera, Paolo; Pernici, Mario

    2013-01-01

    Recently an expansion as a power series in 1/d has been presented for the specific entropy of a complete dimer covering of a d-dimensional hypercubic lattice. This paper extends from 3 to 10 the number of terms known in the series. Likewise an expansion for the entropy, dependent on the dimer-density p, of a monomer-dimer system, involving a sum sum_k a_k(d) p^k, has been recently offered. We herein extend the number of the known expansion coefficients from 6 to 20 for the hyper-cubic lattices of general dimension d and from 6 to 24 for the hyper-cubic lattices of dimensions d 2. The computations of this paper have led us to make the following marvelous conjecture: "In the case of the hyper-cubic lattices, all the expansion coefficients, a_k(d), are positive"! This paper results from a simple melding of two disparate research programs: one computing to high orders the Mayer series coefficients of a dimer gas, the other studying the development of entropy from these coefficients. An effort is made to make thi...

  3. Higher-order risk vulnerability

    OpenAIRE

    Huang,Xiaoping; Stapleton, Richard Christopher

    2017-01-01

    We add an independent unfair background risk to higher-order risk-taking models in the current literature and examine its interaction with the main risk under consideration. Parallel to the well-known concept of risk vulnerability, which is defined by Gollier and Pratt (Econometrica 64:1109–1123, 1996), an agent is said to have a type of higher-order risk vulnerability if adding an independent unfair background risk to wealth raises his level of this type of higher-order risk aversion. We der...

  4. Synaptic properties of thalamic and intracortical inputs to layer 4 of the first- and higher-order cortical areas in the auditory and somatosensory systems.

    Science.gov (United States)

    Lee, Charles C; Sherman, S Murray

    2008-07-01

    The thalamus is an essential structure in the mammalian forebrain conveying information topographically from the sensory periphery to primary neocortical areas. Beyond this initial processing stage, "higher-order" thalamocortical connections have been presumed to serve only a modulatory role, or are otherwise functionally disregarded. Here we demonstrate that these "higher-order" thalamic nuclei share similar synaptic properties with the "first-order" thalamic nuclei. Using whole cell recordings from layer 4 neurons in thalamocortical slice preparations in the mouse somatosensory and auditory systems, we found that electrical stimulation in all thalamic nuclei elicited large, glutamatergic excitatory postsynaptic potentials (EPSPs) that depress in response to repetitive stimulation and that fail to activate a metabotropic glutamate response. In contrast, the intracortical inputs from layer 6 to layer 4 exhibit facilitating EPSPs. These data suggest that higher-order thalamocortical projections may serve a functional role similar to the first-order nuclei, whereas both are physiologically distinct from the intracortical layer 6 inputs. These results suggest an alternate route for information transfer between cortical areas via a corticothalamocortical pathway.

  5. Higher-order organization of complex networks.

    Science.gov (United States)

    Benson, Austin R; Gleich, David F; Leskovec, Jure

    2016-07-08

    Networks are a fundamental tool for understanding and modeling complex systems in physics, biology, neuroscience, engineering, and social science. Many networks are known to exhibit rich, lower-order connectivity patterns that can be captured at the level of individual nodes and edges. However, higher-order organization of complex networks--at the level of small network subgraphs--remains largely unknown. Here, we develop a generalized framework for clustering networks on the basis of higher-order connectivity patterns. This framework provides mathematical guarantees on the optimality of obtained clusters and scales to networks with billions of edges. The framework reveals higher-order organization in a number of networks, including information propagation units in neuronal networks and hub structure in transportation networks. Results show that networks exhibit rich higher-order organizational structures that are exposed by clustering based on higher-order connectivity patterns.

  6. Convergence in infinitary term graph rewriting systems is simple (extended abstract)

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2013-01-01

    In this extended abstract, we present a simple approach to convergence on term graphs that allows us to unify term graph rewriting and infinitary term rewriting. This approach is based on a partial order and a metric on term graphs. These structures arise as straightforward generalisations...... of the corresponding structures used in infinitary term rewriting. We compare our simple approach to a more complicated approach that we developed earlier and show that this new approach is superior in many ways. The only unfavourable property that we were able to identify, viz. failure of full correspondence between...

  7. Tolerance study for the components of the probe-type and hook-type Higher Order Mode couplers for the HL-LHC 800 MHz harmonic system

    CERN Document Server

    Blanco, Esteban

    2016-01-01

    A superconducting 800 MHz second harmonic RF system is one of the considered options as a Landau damping mechanism for HiLumi LHC. The Higher Order Mode (HOM) coupler designs require tight manufacturing tolerances in order to operate at the design specifications. The project consists of defining the mechanical tolerances for the different components of both the probe-type and hook-type HOM coupler. With the use of electromagnetic field simulation software it is possible to identify the critical components of the HOM coupler and to quantify their respective tolerances. The obtained results are discussed in this paper.

  8. Modulational instability and higher-order rogue waves with parameters modulation in a coupled integrable AB system via the generalized Darboux transformation.

    Science.gov (United States)

    Wen, Xiao-Yong; Yan, Zhenya

    2015-12-01

    We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.

  9. Modulational instability and higher-order rogue waves with parameters modulation in a coupled integrable AB system via the generalized Darboux transformation

    Science.gov (United States)

    Wen, Xiao-Yong; Yan, Zhenya

    2015-12-01

    We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.

  10. Nonlocal higher order evolution equations

    KAUST Repository

    Rossi, Julio D.

    2010-06-01

    In this article, we study the asymptotic behaviour of solutions to the nonlocal operator ut(x, t)1/4(-1)n-1 (J*Id -1)n (u(x, t)), x ∈ ℝN, which is the nonlocal analogous to the higher order local evolution equation vt(-1)n-1(Δ)nv. We prove that the solutions of the nonlocal problem converge to the solution of the higher order problem with the right-hand side given by powers of the Laplacian when the kernel J is rescaled in an appropriate way. Moreover, we prove that solutions to both equations have the same asymptotic decay rate as t goes to infinity. © 2010 Taylor & Francis.

  11. Higher-Order Program Generation

    DEFF Research Database (Denmark)

    Rhiger, Morten

    This dissertation addresses the challenges of embedding programming languages, specializing generic programs to specific parameters, and generating specialized instances of programs directly as executable code. Our main tools are higher-order programming techniques and automatic program generatio......), using type-directed partial evaluation. Through various back ends, including a run-time code generator, we generate ML code, C code, and OCaml byte code...

  12. Higher-Order Program Generation

    DEFF Research Database (Denmark)

    Rhiger, Morten

    to the disproportion between general programs that can be executed in several contexts and their specialized counterparts that can be executed efficiently. However, stand-alone partial evaluation is usually too costly when a program must be specialized at run time. We introduce a collection of byte-code combinators...... for OCaml, a dialect of ML, that provides run-time code generation for OCaml programs. We apply these byte-code combinators in semantics-directed compilation for an imperative language and in run-time specialization using type-directed partial evaluation. Finally, we present an approach to compiling goal......This dissertation addresses the challenges of embedding programming languages, specializing generic programs to specific parameters, and generating specialized instances of programs directly as executable code. Our main tools are higher-order programming techniques and automatic program generation...

  13. A rewriting point of view on strategies

    Directory of Open Access Journals (Sweden)

    Hélène Kirchner

    2013-03-01

    Full Text Available This paper is an expository contribution reporting on published work. It focusses on an approach followed in the rewriting community to formalize the concept of strategy. Based on rewriting concepts, several definitions of strategy are reviewed and connected: in order to catch the higher-order nature of strategies, a strategy is defined as a proof term expressed in the rewriting logic or in the rewriting calculus; to address in a coherent way deduction and computation, a strategy is seen as a subset of derivations; and to recover the definition of strategy in sequential path-building games or in functional programs, a strategy is considered as a partial function that associates to a reduction-in-progress, the possible next steps in the reduction sequence.

  14. A Note On Higher Order Grammar

    CERN Document Server

    Gluzberg, Victor

    2009-01-01

    Both syntax-phonology and syntax-semantics interfaces in Higher Order Grammar (HOG) are expressed as axiomatic theories in higher-order logic (HOL), i.e. a language is defined entirely in terms of provability in the single logical system. An important implication of this elegant architecture is that the meaning of a valid expression turns out to be represented not by a single, nor even by a few "discrete" terms (in case of ambiguity), but by a "continuous" set of logically equivalent terms. The note is devoted to precise formulation and proof of this observation.

  15. Solitons and rogue waves for a higher-order nonlinear Schroedinger-Maxwell-Bloch system in an erbium-doped fiber

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chuan-Qi; Gao, Yi-Tian; Yu, Xin [Beijing Univ. of Aeronautics and Astronautics (China). Ministry-of-Education Key Lab. of Fluid Mechanics and National Lab. for Computational Fluid Dynamics; Xue, Long [Beijing Univ. of Aeronautics and Astronautics (China). Ministry-of-Education Key Lab. of Fluid Mechanics and National Lab. for Computational Fluid Dynamics; Aviation Univ. of Air Force, Liaoning (China). Flight Training Base

    2015-07-01

    Under investigation in this article is a higher-order nonlinear Schroedinger-Maxwell-Bloch (HNLS-MB) system for the optical pulse propagation in an erbium-doped fiber. Lax pair, Darboux transformation (DT), and generalised DT for the HNLS-MB system are constructed. Soliton solutions and rogue wave solutions are derived based on the DT and generalised DT, respectively. Properties of the solitons and rogue waves are graphically presented. The third-order dispersion parameter, fourth-order dispersion parameter, and frequency detuning all influence the characteristic lines and velocities of the solitons. The frequency detuning also affects the amplitudes of solitons. The separating function has no effect on the properties of the first-order rogue waves, except for the locations where the first-order rogue waves appear. The third-order dispersion parameter affects the propagation directions and shapes of the rogue waves. The frequency detuning influences the rogue-wave types of the module for the measure of polarization of resonant medium and the extant population inversion. The fourth-order dispersion parameter impacts the rogue-wave interaction range and also has an effect on the rogue-wave type of the extant population inversion. The value of separating function affects the spatial-temporal separation of constituting elementary rogue waves for the second-order and third-order rogue waves. The second-order and third-order rogue waves can exhibit the triangular and pentagon patterns under different choices of separating functions.

  16. Dynamical symmetry and higher-order interactions

    Energy Technology Data Exchange (ETDEWEB)

    Van Isacker, P. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

    1999-07-01

    It is shown that the concept of dynamical symmetry is enriched by increasing the order the interactions between the constituent particles of a given many-body-system. The idea is illustrated with an analysis of higher-order interactions in the interacting boson model. (author)

  17. Analogy, higher order thinking, and education.

    Science.gov (United States)

    Richland, Lindsey Engle; Simms, Nina

    2015-01-01

    Analogical reasoning, the ability to understand phenomena as systems of structured relationships that can be aligned, compared, and mapped together, plays a fundamental role in the technology rich, increasingly globalized educational climate of the 21st century. Flexible, conceptual thinking is prioritized in this view of education, and schools are emphasizing 'higher order thinking', rather than memorization of a cannon of key topics. The lack of a cognitively grounded definition for higher order thinking, however, has led to a field of research and practice with little coherence across domains or connection to the large body of cognitive science research on thinking. We review literature on analogy and disciplinary higher order thinking to propose that relational reasoning can be productively considered the cognitive underpinning of higher order thinking. We highlight the utility of this framework for developing insights into practice through a review of mathematics, science, and history educational contexts. In these disciplines, analogy is essential to developing expert-like disciplinary knowledge in which concepts are understood to be systems of relationships that can be connected and flexibly manipulated. At the same time, analogies in education require explicit support to ensure that learners notice the relevance of relational thinking, have adequate processing resources available to mentally hold and manipulate relations, and are able to recognize both the similarities and differences when drawing analogies between systems of relationships.

  18. Vector bright soliton behaviors of the coupled higher-order nonlinear Schrödinger system in the birefringent or two-mode fiber.

    Science.gov (United States)

    Liu, Lei; Tian, Bo; Xie, Xi-Yang; Guan, Yue-Yang

    2017-01-01

    Studied in this paper are the vector bright solitons of the coupled higher-order nonlinear Schrödinger system, which describes the simultaneous propagation of two ultrashort pulses in the birefringent or two-mode fiber. With the help of auxiliary functions, we obtain the bilinear forms and construct the vector bright one- and two-soliton solutions via the Hirota method and symbolic computation. Two types of vector solitons are derived. Single-hump, double-hump, and flat-top solitons are displayed. Elastic and inelastic interactions between the Type-I solitons, between the Type-II solitons, and between the two combined types of the solitons are revealed, respectively. Especially, from the interaction between a Type-I soliton and a Type-II soliton, we see that the Type-II soliton exhibits the oscillation periodically before such an interaction and becomes the double-hump soliton after the interaction, which is different from the previously reported.

  19. From Regular to Context Free to Mildly Context Sensitive Tree Rewriting Systems The Path of Child Language Acquisition

    CERN Document Server

    Frank, R

    1994-01-01

    Current syntactic theory limits the range of grammatical variation so severely that the logical problem of grammar learning is trivial. Yet, children exhibit characteristic stages in syntactic development at least through their sixth year. Rather than positing maturational delays, I suggest that acquisition difficulties are the result of limitations in manipulating grammatical representations. I argue that the genesis of complex sentences reflects increasing generative capacity in the systems generating structural descriptions: conjoined clauses demand only a regular tree rewriting system; sentential embedding uses a context-free tree substitution grammar; modification requires TAG, a mildly context-sensitive system.

  20. Moments of rewriting

    African Journals Online (AJOL)

    Court of Law because there has emerged the professional called the lawyer who must speak .... The literary interview is a discourse that occupies the borderland .... rewriting should be understood as any changing of the pristine primal text into .... a moment of rewriting the Self But the resistance is also a moment of rewriting.

  1. Scoped Dynamic Rewrite Rules

    NARCIS (Netherlands)

    Visser, Eelco

    2002-01-01

    The applicability of term rewriting to program transformation is limited by the lack of control over rule application and by the context-free nature of rewrite rules. The first problem is addressed by languages supporting user-definable rewriting strategies. This paper addresses the second problem b

  2. A Formalization of Newman's and Yokouchi's Lemmas in a Higher-Order Language

    Directory of Open Access Journals (Sweden)

    Andre Luiz Galdino

    2008-12-01

    Full Text Available This paper shows how a formalization for the theory of Abstract Reduction Systems (ARSs in which noetherianity was specified by the notion of well-foundness over binary relations is used in order to prove results such as the well-known Newman's and Yokouchi's Lemmas. The former is known as the diamond lemma and the latter states a property of commutation between ARSs. The theory ars was specified in the Prototype Verification System (PVS for which to the best of our knowledge there was no available theory for dealing with rewriting techniques in general before this development. In addition to proof techniques available in the higher-order specification language of PVS, the verification of these lemmas implies an elaborated use of natural and noetherian induction.

  3. 项重写系统弱基终止性的归纳证明%An Inductive Proving Method for Weakly Ground Termination of Term Rewriting Systems

    Institute of Scientific and Technical Information of China (English)

    冯速

    2001-01-01

    This paper proposes a novel method for proving weakly ground termination in a restricted domain of a term rewriting system based on structural and cover set induction. For this prupose,we introduce the concepts of base set and set of ground terms defined recursively over base sets,which plays a crucial role in the inductive method. The method can be used for non-terminating,non-confluent and/or non-linear term rewriting systems,and have application in inductive equivalence testing and program verification.

  4. Reinterpreting Compression in Infinitary Rewriting

    NARCIS (Netherlands)

    Ketema, J.; Tiwari, Ashish

    2012-01-01

    Departing from a computational interpretation of compression in infinitary rewriting, we view compression as a degenerate case of standardisation. The change in perspective comes about via two observations: (a) no compression property can be recovered for non-left-linear systems and (b) some standar

  5. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk;

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  6. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  7. Towards regularized higher-order computations in QFT without DREG

    CERN Document Server

    Sborlini, German F R; Hernandez-Pinto, Roger; Rodrigo, German

    2016-01-01

    In this talk, we review the basis of the loop-tree duality theorem, which allows to rewrite loop scattering amplitudes in terms of tree-level like objects. Since the loop measure is converted into a phase-space one, both virtual and real contributions are expressible using the same integration variables. A physically motivated momentum mapping allows to generate the real emission process starting from the Born kinematics and the loop momenta. The integrand-level combination leads to regular functions, which can be integrated without using dimensional regularization (DREG) and correctly reproduce the finite higher-order corrections to physical observables. We explain the implementation of this novel approach to compute some benchmark physical processes, and we show how to deal with both infrared and ultraviolet divergences in four space-time dimensions.

  8. The regular state in higher order gravity

    Science.gov (United States)

    Cotsakis, Spiros; Kadry, Seifedine; Trachilis, Dimitrios

    2016-08-01

    We consider the higher-order gravity theory derived from the quadratic Lagrangian R + 𝜖R2 in vacuum as a first-order (ADM-type) system with constraints, and build time developments of solutions of an initial value formulation of the theory. We show that all such solutions, if analytic, contain the right number of free functions to qualify as general solutions of the theory. We further show that any regular analytic solution which satisfies the constraints and the evolution equations can be given in the form of an asymptotic formal power series expansion.

  9. Analytic modeling of instabilities driven by higher-order modes in the HLS Ⅱ RF system with a higher-harmonic cavity

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu-Ning; LI Wei-Min; WU Cong-Feng; WANG Lin

    2013-01-01

    The utility of a passive fourth-harmonic cavity plays a key role in suppressing longitudinal beam instabilities in the electron storage ring and lengthens the bunch by a factor of 2.6 for the phase Ⅱ project of the Hefei Light Source (HLS Ⅱ).Meanwhile,instabilities driven by higher-order modes (HOM) may limit the performance of the higher-harmonic cavity.In this paper,the parasitic coupled-bunch instability,which is driven by narrow band parasitic modes,and the microwave instability,which is driven by broadband HOM,are both modeled analytically.The analytic modeling results are in good agreement with those of our previous simulation study and indicate that the passive fourth-harmonic cavity suppresses parasitic coupled-bunch instabilities and microwave instability.The modeling suggests that a fourth-harmonic cavity may be successfully used at the HLS Ⅱ.

  10. Analytic modeling of instabilities driven by higher-order modes in HLS II RF system with a higher-harmonic cavity

    CERN Document Server

    Zhao, Yuning; Wu, Congfeng; Wang, Lin

    2013-01-01

    The utility of a passive fourth-harmonic cavity plays key role in suppressing longitudinal beam instabilities in the electron storage ring and lengthens the bunch by a factor of 2.6 for the phase II project of Hefei Light Source(HLS II). Meanwhile, instabilities driven by higher-order modes(HOM) may limit the performance of the higher-harmonic cavity. In this paper, the parasitic coupled-bunch instability which is driven by narrow band parasitic modes and the microwave instability which is driven by broadband HOM are both modeled analytically. The analytic modeling results are in good agreement with that of our previous simulation study and indicate that the passive fourth-harmonic cavity suppresses parasitic coupled-bunch instabilities and the microwave instability. The modeling suggests that a fourth-harmonic cavity may be successfully used at HLS II.

  11. Meaningless terms in rewriting

    NARCIS (Netherlands)

    Kennaway, R.; Oostrom, V. van; Vries, F.-J. de

    2008-01-01

    We present an axiomatic approach to the concept of meaninglessness in finite and transfinite term rewriting and lambda calculus. We justify our axioms in several ways. They can be intuitively justified from the viewpoint of rewriting as computation. They are shown to imply important properties of me

  12. ARM : abstract rewriting machine

    NARCIS (Netherlands)

    J.F.T. Kamperman; H.R. Walters (Pum)

    1993-01-01

    textabstractTerm rewriting is frequently used as implementation technique for algebraic specifications. In this paper we present the abstract term rewriting machine (ARM), which has an extremely compact instruction set and imposes no restrictions on the implemented TRSs. Apart from standard

  13. Invention, Rewriting, Usurpation

    DEFF Research Database (Denmark)

    2011-01-01

    Conference volume from the conference Invention, Rewriting, Usurpation. Discursive Fights over Religious Traditions in Antiquity, Aarhus / Ebeltoft May 30 - June 4, 2010.......Conference volume from the conference Invention, Rewriting, Usurpation. Discursive Fights over Religious Traditions in Antiquity, Aarhus / Ebeltoft May 30 - June 4, 2010....

  14. Invention, Rewriting, Usurpation

    DEFF Research Database (Denmark)

    2011-01-01

    Conference volume from the conference Invention, Rewriting, Usurpation. Discursive Fights over Religious Traditions in Antiquity, Aarhus / Ebeltoft May 30 - June 4, 2010.......Conference volume from the conference Invention, Rewriting, Usurpation. Discursive Fights over Religious Traditions in Antiquity, Aarhus / Ebeltoft May 30 - June 4, 2010....

  15. Nonconservative higher-order hydrodynamic modulation instability

    Science.gov (United States)

    Kimmoun, O.; Hsu, H. C.; Kibler, B.; Chabchoub, A.

    2017-08-01

    The modulation instability (MI) is a universal mechanism that is responsible for the disintegration of weakly nonlinear narrow-banded wave fields and the emergence of localized extreme events in dispersive media. The instability dynamics is naturally triggered, when unstable energy sidebands located around the main energy peak are excited and then follow an exponential growth law. As a consequence of four wave mixing effect, these primary sidebands generate an infinite number of additional sidebands, forming a triangular sideband cascade. After saturation, it is expected that the system experiences a return to initial conditions followed by a spectral recurrence dynamics. Much complex nonlinear wave field motion is expected, when the secondary or successive sideband pair that is created is also located in the finite instability gain range around the main carrier frequency peak. This latter process is referred to as higher-order MI. We report a numerical and experimental study that confirms observation of higher-order MI dynamics in water waves. Furthermore, we show that the presence of weak dissipation may counterintuitively enhance wave focusing in the second recurrent cycle of wave amplification. The interdisciplinary weakly nonlinear approach in addressing the evolution of unstable nonlinear waves dynamics may find significant resonance in other nonlinear dispersive media in physics, such as optics, solids, superfluids, and plasma.

  16. Higher order assortativity in complex networks

    CERN Document Server

    Arcagni, Alberto; Stefani, Silvana; Torriero, Anna

    2016-01-01

    Assortativity was first introduced by Newman and has been extensively studied and applied to many real world networked systems since then. Assortativity is a graph metrics and describes the tendency of high degree nodes to be directly connected to high degree nodes and low degree nodes to low degree nodes. It can be interpreted as a first order measure of the connection between nodes, i.e. the first autocorrelation of the degree-degree vector. Even though assortativity has been used so extensively, to the author's knowledge, no attempt has been made to extend it theoretically. This is the scope of our paper. We will introduce higher order assortativity by extending the Newman index based on a suitable choice of the matrix driving the connections. Higher order assortativity will be defined for paths, shortest paths, random walks of a given time length, connecting any couple of nodes. The Newman assortativity is achieved for each of these measures when the matrix is the adjacency matrix, or, in other words, the...

  17. Higher order mechanics on graded bundles

    Science.gov (United States)

    Bruce, Andrew James; Grabowska, Katarzyna; Grabowski, Janusz

    2015-05-01

    In this paper we develop a geometric approach to higher order mechanics on graded bundles in both, the Lagrangian and Hamiltonian formalism, via the recently discovered weighted algebroids. We present the corresponding Tulczyjew triple for this higher order situation and derive in this framework the phase equations from an arbitrary (also singular) Lagrangian or Hamiltonian, as well as the Euler-Lagrange equations. As important examples, we geometrically derive the classical higher order Euler-Lagrange equations and analogous reduced equations for invariant higher order Lagrangians on Lie groupoids.

  18. Conformal higher-order viscoelastic fluid mechanics

    CERN Document Server

    Fukuma, Masafumi

    2012-01-01

    We present a generally covariant formulation of conformal higher-order viscoelastic fluid mechanics with strain allowed to take arbitrarily large values. We give a general prescription to determine the dynamics of a relativistic viscoelastic fluid in a way consistent with the hypothesis of local thermodynamic equilibrium and the second law of thermodynamics. We then elaborately study the transient time scales at which the strain almost relaxes and becomes proportional to the gradients of velocity. We particularly show that a conformal second-order fluid with all possible parameters in the constitutive equations can be obtained without breaking the hypothesis of local thermodynamic equilibrium, if the conformal fluid is defined as the long time limit of a conformal second-order viscoelastic system. We also discuss how local thermodynamic equilibrium could be understood in the context of the fluid/gravity correspondence.

  19. Conformal higher-order viscoelastic fluid mechanics

    Science.gov (United States)

    Fukuma, Masafumi; Sakatani, Yuho

    2012-06-01

    We present a generally covariant formulation of conformal higher-order viscoelastic fluid mechanics with strain allowed to take arbitrarily large values. We give a general prescription to determine the dynamics of a relativistic viscoelastic fluid in a way consistent with the hypothesis of local thermodynamic equilibrium and the second law of thermodynamics. We then elaborately study the transient time scales at which the strain almost relaxes and becomes proportional to the gradients of velocity. We particularly show that a conformal second-order fluid with all possible parameters in the constitutive equations can be obtained without breaking the hypothesis of local thermodynamic equilibrium, if the conformal fluid is defined as the long time limit of a conformal second-order viscoelastic system. We also discuss how local thermodynamic equilibrium could be understood in the context of the fluid/gravity correspondence.

  20. Static Complexity Analysis of Higher Order Programs

    DEFF Research Database (Denmark)

    Avery, James Emil; Kristiansen, Lars; Moyen, Jean-Yves

    2009-01-01

    The overall goal of the research presented in this paper is to find^M automatic methods for static complexity analysis of higher order^M programs.......The overall goal of the research presented in this paper is to find^M automatic methods for static complexity analysis of higher order^M programs....

  1. Linear-algebraic Lambda-calculus: higher-order, encodings and confluence

    CERN Document Server

    Arrighi, P; Arrighi, Pablo; Dowek, Gilles

    2006-01-01

    We introduce a minimal language combining both higher-order computation and linear algebra. Roughly, this is nothing else than the Lambda-calculus together with the possibility to make linear combinations of terms a.t+b.u. We describe how to "execute" this language in terms of a few rewrite rules, and justify them through the two fundamental requirements that the language be a language of linear operators, and that it be higher-order. We mention the perspectives of this work in field of quantum computation, which we show can be easily encoded in the calculus, as well as in other domains such as the interpretation of linear logic. Finally we prove the confluence of the calculus, this is our main result. Keywords: quantum programming language, quantum control, quantum logic, probabilistic and quantitative analysis, rewriting techniques.

  2. Mei Symmetry and New Conserved Quantities of Tzénoff Equations for the Variable Mass Higher-Order Nonholonomic System

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Wang; WANG Jian-Bo; CHEN Xiang-Wei; XIE Jia-Fang

    2012-01-01

    Operational systems of spacecraft are general variable mass mechanics systems,and their symmetries and conserved quantities imply profound physical rules of the space system.We study the Mei symmetry of Tzénoff equations for a variable mass nonholonomic system and the new conserved quantities derived.The function expression of the new conserved quantities and the criterion equation which deduces these conserved quantities are presented.This result has some theoretical values in further research of conservation laws obeyed by the variable mass system.%Operational systems of spacecraft are general variable mass mechanics systems, and their symmetries and conserved quantities imply profound physical rules of the space system. We study the Mei symmetry of Tzenoff equations for a variable mass nonholonomic system and the new conserved quantities derived. The function expression of the new conserved quantities and the criterion equation which deduces these conserved quantities are presented. This result has some theoretical values in further research of conservation laws obeyed by the variable mass system.

  3. Stratego: a language for program transformation based on rewriting strategies : system description of Stratego 0.5

    NARCIS (Netherlands)

    Visser, Eelco

    2002-01-01

    Program transformation is used in many areas of software engineering. Examples include compilation, optimization, synthesis, refactoring, migration, normalization and improvement [15]. Rewrite rules are a natural formalism for expressing single program transformations. However, using a standard stra

  4. Synchrotron radiation of higher order soliton

    CERN Document Server

    Driben, Rodislav; Efimov, Anatoly

    2015-01-01

    We demonstrate radiation mechanism exhibited by higher order soliton. In a course of its evolution higher order soliton emits polychromatic radiation resulting in appearance of multipeak frequency comb like spectral band. The shape and spectral position of this band can be effectively controlled by the relative strength of the third order dispersion. An analytical description is completely corroborated by numerical simulations. An analogy between this radiation and the radiation of moving charges is presented. For longer pulses the described effect persists also under the action of higher order perturbations such as Raman and self-steepening.

  5. 具有高阶项的弹性杆振动系统的稳定性%Stability of Higher Order Vibration System of Elastic Rod

    Institute of Scientific and Technical Information of China (English)

    裴金仙

    2012-01-01

    There is strong application background for the mathematical model describing elastic rod. The elastic rod vibration system of the initial boundary value problem was studied and the stability of the solutions was discussed. For there is no explicit solution could not obtained, the study on the system's stability becomes necessary. Using the energy method, the decay result of the solutions was obtained. The result shows that the system was of polynomial stability, and can be generalized to the elastic rod system with damping.%弹性杆描述的数学模型有很强的实际背景,对一类弹性杆的振动系统进行了研究,分析了系统的稳定性.由于该系统的显式解求不出来,因此对其稳定性的讨论就是很必要的.利用能量方法证明了系统解的衰减性结果,给出了系统是多项式稳定的.该结果推广到具有阻尼的弹性杆振动系统的渐近稳定性.

  6. Higher-order techniques in computational electromagnetics

    CERN Document Server

    Graglia, Roberto D

    2016-01-01

    Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.

  7. On higher order relations in Fedosov supermanifolds

    Energy Technology Data Exchange (ETDEWEB)

    Lavrov, P M; Radchenko, O V [Tomsk State Pedagogical University, 634041 Tomsk (Russian Federation)

    2006-05-26

    Higher order relations existing in normal coordinates between affine extensions of the symplectic curvature tensor and basic objects for any Fedosov supermanifolds are derived. Representation of these relations in general coordinates is discussed.

  8. Higher order relations in Fedosov supermanifolds

    CERN Document Server

    Lavrov, P M

    2005-01-01

    Higher order relations existing in normal coordinates between affine extensions of the curvature tensor and basic objects for any Fedosov supermanifolds are derived. Representation of these relations in general coordinates is discussed.

  9. Simulation of Thermo-fluid Interactions in Cryogenic Stage Turbine Startup System Using AUSM+-UP-based Higher-order Accurate Flow Solver

    Directory of Open Access Journals (Sweden)

    Praveen Nair

    2009-05-01

    Full Text Available High-speed turbines are used in upper stage liquid engines of launch vehicles and the most common ones include LH2 and LOX turbines used in the cryogenic stages. The main constraints in the design of turbine system for a liquid engine are thermal loads, mass flow and pressure drops in various systems ahead of the turbine inlet. The temperature of the combustion products/gases reaching the turbine blades must be well below the melting point of the turbine blade material and the mass flow rate must be sufficient to generate the required power. Turbine can be started in two ways, by generating gases using a solid propellant-based spinner motor, and using compressed gases stored in gas bottles. The first method involves design challenges but requires less space and weight. On the other hand, second method is simple but requires more space. Because of the space and weight constraints associated with the upper stages, first method is preferred and discussed in this paper. It consists of a solid propellant-based spinner motor with a convergent-divergent nozzle, a guiding duct connecting nozzle exit, and the turbine inlet manifold in the form of a torroid with nozzle block having 39 guiding nozzles. The combustion products generated by the spinner motor are guided to the manifold through the guiding duct. Inlet manifold acts as a reservoir and supplies hot gases uniformly to the turbine through 39 nozzles. This study addresses the role of  computational fluid dynamics in the design of turbine startup system using unstructured cell-centered AUSM+-UP-based finite volume solver with the twoequation turbulence model. The flow and the thermal characteristics of the solid motor with a convergentdivergent nozzle were studied to evaluate the gas temperature, operating pressure, and flow velocities. The guiding duct along with the inlet manifold was analysed separately to find the drop in temperature and pressure within the system. From the simulation

  10. Measuring violations of General Relativity from single gravitational wave detection by non-spinning binary systems: higher-order asymptotic analysis

    CERN Document Server

    Tso, Rhondale

    2015-01-01

    A frequentist asymptotic expansion method for error estimation is employed for a network of gravitational wave detectors to assess the capability of gravitational wave observations, with Adv. LIGO and Adv. Virgo, to distinguish between the post-Einsteinian (ppE) description of coalescing binary systems and that of GR. When such errors are smaller than the parameter value, there is possibility to detect these violations from GR. A parameter space with inclusion of dominant dephasing ppE parameters is used for a study of first- and second-order (co)variance expansions, focusing on the inspiral stage of a nonspinning binary system of zero eccentricity detectible through Adv. LIGO and Adv. Virgo. Our procedure is more reliable than frequentist studies based only on Fisher information estimates and complements Bayesian studies. Second-order asymptotics indicate the possibility of constraining deviations from GR in low-SNR ($\\rho \\sim 15-17$) regimes. The errors on $\\beta$ also increase errors of other parameters s...

  11. Term Graph Rewriting and Parallel Term Rewriting

    CERN Document Server

    Corradini, Andrea; 10.4204/EPTCS.48.3

    2011-01-01

    The relationship between Term Graph Rewriting and Term Rewriting is well understood: a single term graph reduction may correspond to several term reductions, due to sharing. It is also known that if term graphs are allowed to contain cycles, then one term graph reduction may correspond to infinitely many term reductions. We stress that this fact can be interpreted in two ways. According to the "sequential interpretation", a term graph reduction corresponds to an infinite sequence of term reductions, as formalized by Kennaway et.al. using strongly converging derivations over the complete metric space of infinite terms. Instead according to the "parallel interpretation" a term graph reduction corresponds to the parallel reduction of an infinite set of redexes in a rational term. We formalize the latter notion by exploiting the complete partial order of infinite and possibly partial terms, and we stress that this interpretation allows to explain the result of reducing circular redexes in several approaches to te...

  12. A 2.5-dimensional viscous, resistive, advective magnetized accretion-outflow coupling in black hole systems: A higher order polynomial approximation. I

    CERN Document Server

    Ghosh, Shubhrangshu

    2016-01-01

    The correlated and coupled dynamics of accretion and outflow around black holes (BHs) are essentially governed by the fundamental laws of conservation as outflow extracts matter, momentum and energy from the accretion region. Here we analyzed a robust form of 2.5-dimensional viscous, resistive, advective magnetized accretion-outflow coupling in BH systems, in the mean field magnetohydrodynamical (MHD) regime. We solve the complete set of coupled MHD conservation equations self-consistently, through invoking a generalized polynomial expansion in two dimensions. We perform a critical analysis of accretion-outflow region and provide a complete quasi-analytical family of solutions for advective flows. We obtain the physical plausible outflow solutions at high turbulent viscosity parameter $\\alpha \\, (\\ge 0.3)$, and at a reduced scale-height, as magnetic stresses compress or squeeze the flow region. We found that the value of the large-scale poloidal magnetic field $\\bar B_P$ is enhanced with increasing geometrica...

  13. Term Graph Rewriting and Parallel Term Rewriting

    Directory of Open Access Journals (Sweden)

    Andrea Corradini

    2011-02-01

    Full Text Available The relationship between Term Graph Rewriting and Term Rewriting is well understood: a single term graph reduction may correspond to several term reductions, due to sharing. It is also known that if term graphs are allowed to contain cycles, then one term graph reduction may correspond to infinitely many term reductions. We stress that this fact can be interpreted in two ways. According to the "sequential interpretation", a term graph reduction corresponds to an infinite sequence of term reductions, as formalized by Kennaway et.al. using strongly converging derivations over the complete metric space of infinite terms. Instead according to the "parallel interpretation" a term graph reduction corresponds to the parallel reduction of an infinite set of redexes in a rational term. We formalize the latter notion by exploiting the complete partial order of infinite and possibly partial terms, and we stress that this interpretation allows to explain the result of reducing circular redexes in several approaches to term graph rewriting.

  14. Higher Order Cumulants in Colorless Partonic Plasma

    CERN Document Server

    Cherif, S; Ladrem, M

    2016-01-01

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume $T_{0}(V)$, a new approach based on the finite-size cumulant expansion of the order parameter and the $\\mathscr{L}_{m,n}$-Method is used.We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase...

  15. Solution of Higher-Order ODEs Using Backward Difference Method

    Directory of Open Access Journals (Sweden)

    Mohamed Bin Suleiman

    2011-01-01

    Full Text Available The current numerical technique for solving a system of higher-order ordinary differential equations (ODEs is to reduce it to a system of first-order equations then solving it using first-order ODE methods. Here, we propose a method to solve higher-order ODEs directly. The formulae will be derived in terms of backward difference in a constant stepsize formulation. The method developed will be validated by solving some higher-order ODEs directly with constant stepsize. To simplify the evaluations of the integration coefficients, we find the relationship between various orders. The result presented confirmed our hypothesis.

  16. Higher-order awareness, misrepresentation and function.

    Science.gov (United States)

    Rosenthal, David

    2012-05-19

    Conscious mental states are states we are in some way aware of. I compare higher-order theories of consciousness, which explain consciousness by appeal to such higher-order awareness (HOA), and first-order theories, which do not, and I argue that higher-order theories have substantial explanatory advantages. The higher-order nature of our awareness of our conscious states suggests an analogy with the metacognition that figures in the regulation of psychological processes and behaviour. I argue that, although both consciousness and metacognition involve higher-order psychological states, they have little more in common. One thing they do share is the possibility of misrepresentation; just as metacognitive processing can misrepresent one's cognitive states and abilities, so the HOA in virtue of which one's mental states are conscious can, and sometimes does, misdescribe those states. A striking difference between the two, however, has to do with utility for psychological processing. Metacognition has considerable benefit for psychological processing; in contrast, it is unlikely that there is much, if any, utility to mental states' being conscious over and above the utility those states have when they are not conscious.

  17. Exploiting Higher-order Derivatives in Computational Optimal Control

    OpenAIRE

    Ross, I. Michael; Rea, Jeremy; Fahroo, Fariba

    2002-01-01

    Proceedings of the 10th Mediterranean Conference on Control and Automation -- MED 2002 , Lisbon, Portugal, July7 9-12, 2002 To facilitate generation of real-time solutions to nonlinear optimal control problems, we present a new way of approximating higher-order derivatives that arise in control systems. A Legendre pseudospectral method is presented to efficiently and accurately discretize optimal control problems governed by higher-order dynamical constraints. For mechanical systems, a re...

  18. Human motion perception: Higher-order organization

    Science.gov (United States)

    Kaiser, Mary K.; Proffitt, Dennis R.

    1990-01-01

    An overview is given of higher-order motion perception and organization. It is argued that motion is sufficient to fully specify a number of environmental properties, including: depth order, three-dimensional form, object displacement, and dynamics. A grammar of motion perception is proposed; applications of this work for display design are discussed.

  19. Higher-Order Minimal Functional Graphs

    DEFF Research Database (Denmark)

    Jones, Neil D; Rosendahl, Mads

    1994-01-01

    We present a minimal function graph semantics for a higher-order functional language with applicative evaluation order. The semantics captures the intermediate calls performed during the evaluation of a program. This information may be used in abstract interpretation as a basis for proving...

  20. Frontiers of higher order fuzzy sets

    CERN Document Server

    Tahayori, Hooman

    2015-01-01

    Frontiers of Higher Order Fuzzy Sets, strives to improve the theoretical aspects of general and Interval Type-2 fuzzy sets and provides a unified representation theorem for higher order fuzzy sets. Moreover, the book elaborates on the concept of gradual elements and their integration with the higher order fuzzy sets. This book also introduces new frameworks for information granulation based on general T2FSs, IT2FSs, Gradual elements, Shadowed sets and rough sets. In particular, the properties and characteristics of the new proposed frameworks are studied. Such new frameworks are shown to be more capable to be exploited in real applications. Higher order fuzzy sets that are the result of the integration of general T2FSs, IT2FSs, gradual elements, shadowed sets and rough sets will be shown to be suitable to be applied in the fields of bioinformatics, business, management, ambient intelligence, medicine, cloud computing and smart grids. Presents new variations of fuzzy set frameworks and new areas of applicabili...

  1. Higher Order Thinking in the Dance Studio

    Science.gov (United States)

    Moffett, Ann-Thomas

    2012-01-01

    The author identifies higher order thinking as an essential component of dance training for students of all ages and abilities. Weaving together insights from interviews with experts in the field of dance education with practical pedagogical applications within an Improvisation and Composition class for talented and gifted youth, this article…

  2. Higher-Order Components for Grid Programming

    CERN Document Server

    Dünnweber, Jan

    2009-01-01

    Higher-Order Components were developed within the CoreGRID European Network of Excellence and have become an optional extension of the popular Globus middleware. This book provides the reader with hands-on experience, describing a collection of example applications from various fields of science and engineering, including biology and physics.

  3. Implementation of higher-order absorbing boundary conditions for the Einstein equations

    CERN Document Server

    Rinne, Oliver; Scheel, Mark A; Pfeiffer, Harald P

    2008-01-01

    We present an implementation of absorbing boundary conditions for the Einstein equations based on the recent work of Buchman and Sarbach. In this paper, we assume that spacetime may be linearized about Minkowski space close to the outer boundary, which is taken to be a coordinate sphere. We reformulate the boundary conditions as conditions on the gauge-invariant Regge-Wheeler-Zerilli scalars. Higher-order radial derivatives are eliminated by rewriting the boundary conditions as a system of ODEs for a set of auxiliary variables intrinsic to the boundary. From these we construct boundary data for a set of well-posed constraint-preserving boundary conditions for the Einstein equations in a first-order generalized harmonic formulation. This construction has direct applications to outer boundary conditions in simulations of isolated systems (e.g., binary black holes) as well as to the problem of Cauchy-perturbative matching. As a test problem for our numerical implementation, we consider linearized multipolar grav...

  4. Higher order derivatives of R-Jacobi polynomials

    Science.gov (United States)

    Das, Sourav; Swaminathan, A.

    2016-06-01

    In this work, the R-Jacobi polynomials defined on the nonnegative real axis related to F-distribution are considered. Using their Sturm-Liouville system higher order derivatives are constructed. Orthogonality property of these higher ordered R-Jacobi polynomials are obtained besides their normal form, self-adjoint form and hypergeometric representation. Interesting results on the Interpolation formula and Gaussian quadrature formulae are obtained with numerical examples.

  5. Infinitary Rewriting - Theory and Applications

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2009-01-01

    significant problem that arises in infinitary rewriting is the inherent difficulty to finitely represent and, hence, to implement it. To this end, we consider term graph rewriting, which is able to finitely represent restricted forms of infinitary term rewriting. Moreover, we study different models...

  6. Higher order microfibre modes for dielectric particle trapping and propulsion

    CERN Document Server

    Maimaiti, Aili; Sergides, Marios; Gusachenko, Ivan; Chormaic, Síle Nic

    2014-01-01

    Optical manipulation in the vicinity of optical micro- and nanofibres has shown potential across several fields in recent years, including microparticle control, and cold atom probing and trapping. To date, most work has focussed on propagation of the fundamental mode through the fibre. However, along the maximum mode intensity axis, higher order modes have a longer evanescent field extension and larger field amplitude at the fibre waist compared to the fundamental mode, opening up new possibilities for optical manipulation and particle trapping. In this work, we demonstrate a microfibre/optical tweezers compact system for trapping and propelling dielectric particles based on the excitation of the first group of higher order modes at the fibre waist. Single polystyrene particles were trapped and propelled in the evanescent fields of higher order and fundamental modes near the surface of microfibres. Speed enhancement of particle propulsion was observed for the higher order modes compared to the fundamental mo...

  7. A Higher-Order Colon Translation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Nielsen, Lasse R.

    2000-01-01

    A lambda-encoding such as the CPS transformation gives rise to administrative redexes. In his seminal article ``Call-by-name, call-by-value and the lambda-calculus'', 25 years ago, Plotkin tackled administrative reductions using a so-called ``colon translation.'' 10 years ago, Danvy and Filinski...... integrated administrative reductions in the CPS transformation, making it operate in one pass. The technique applies to other lambda-encodings (e.g., variants of CPS), but we do not see it used in practice--instead, Plotkin's colon translation appears to be favored. Therefore, in an attempt to link both...... techniques, we recast Plotkin's proof of Indifference and Simulation to the higher-order specification of the one-pass CPS transformation. To this end, we extend his colon translation from first order to higher order...

  8. A Higher-Order Colon Translation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Nielsen, Lasse Reichstein

    2001-01-01

    A lambda-encoding such as the CPS transformation gives rise to administrative redexes. In his seminal article ``Call-by-name, call-by-value and the lambda-calculus'', 25 years ago, Plotkin tackled administrative reductions using a so-called ``colon translation.'' 10 years ago, Danvy and Filinski...... integrated administrative reductions in the CPS transformation, making it operate in one pass. The technique applies to other lambda-encodings (e.g., variants of CPS), but we do not see it used in practice--instead, Plotkin's colon translation appears to be favored. Therefore, in an attempt to link both...... techniques, we recast Plotkin's proof of Indifference and Simulation to the higher-order specification of the one-pass CPS transformation. To this end, we extend his colon translation from first order to higher order...

  9. Higher order structure in ribosomal RNA.

    Science.gov (United States)

    Gutell, R R; Noller, H F; Woese, C R

    1986-05-01

    The only reliable general method currently available for determining precise higher order structure in the large ribosomal RNAs is comparative sequence analysis. The method is here applied to reveal 'tertiary' structure in the 16S-like rRNAs, i.e. structure more complex than simple double-helical, secondary structure. From a list of computer-generated potential higher order interactions within 16S rRNA one such interaction considered likely was selected for experimental test. The putative interaction involves a Watson-Crick one to one correspondence between positions 570 and 866 in the molecule (E. coli numbering). Using existing oligonucleotide catalog information several organisms were selected whose 16S rRNA sequences might test the proposed co-variation. In all of the (phylogenetically independent) cases selected, full sequence evidence confirms the predicted one to one (Watson-Crick) correspondence. An interaction between positions 570 and 866 is, therefore, considered proven phylogenetically.

  10. Higher-Order Mentalising and Executive Functioning.

    Science.gov (United States)

    2015-11-01

    Higher-order mentalising is the ability to represent the beliefs and desires of other people at multiple, iterated levels - a capacity that sets humans apart from other species. However, there has not yet been a systematic attempt to determine what cognitive processes underlie this ability. Here we present three correlational studies assessing the extent to which performance on higher-order mentalising tasks relates to emotion recognition, self-reported empathy and self-inhibition. In Study 1a and 1b, examining emotion recognition and empathy, a relationship was identified between individual differences in the ability to mentalise and an emotion recognition task (the Reading the Mind in the Eyes task), but no correlation was found with the Empathy Quotient, a self-report scale of empathy. Study 2 investigated whether a relationship exists between individual mentalising abilities and four different forms of self-inhibition: motor inhibition, executive inhibition, automatic imitation and temporal discounting. Results demonstrate that only temporal discounting performance relates to mentalising ability; suggesting that cognitive skills relevant to representation of the minds of others' are not influenced by the ability to perform more basic inhibition. Higher-order mentalising appears to rely on the cognitive architecture that serves both low-level social cognition (emotion recognition), and complex forms of inhibition.

  11. Medical Data Transformation Using Rewriting

    Directory of Open Access Journals (Sweden)

    Naveen eAshish

    2015-02-01

    Full Text Available This paper presents an approach to and system for declaratively transforming medical subjects’ data into a common data model representation. Our work is part of the GAAIN project on Alzheimer’s disease data federation. We present a general purpose data transformation system that we have developed by leveraging the existing state-of-the-art in data integration and query rewriting. In this work we have further extended the current technology with new formalisms that facilitate expressing a broader range of data transformation tasks, plus new execution methodologies to ensure efficient data transformation for disease datasets.

  12. Triangulation in rewriting

    NARCIS (Netherlands)

    Oostrom, V. van; Zantema, Hans

    2012-01-01

    We introduce a process, dubbed triangulation, turning any rewrite relation into a confluent one. It is more direct than usual completion, in the sense that objects connected by a peak are directly oriented rather than their normal forms. We investigate conditions under which this process preserves d

  13. Triangulation in rewriting

    NARCIS (Netherlands)

    Oostrom, V. van; Zantema, Hans

    2012-01-01

    We introduce a process, dubbed triangulation, turning any rewrite relation into a confluent one. It is more direct than usual completion, in the sense that objects connected by a peak are directly oriented rather than their normal forms. We investigate conditions under which this process preserves d

  14. Rewritable azobenzene polyester for polarization holographic data storage

    DEFF Research Database (Denmark)

    Kerekes, A; Sajti, Sz.; Loerincz, Emoeke;

    2000-01-01

    Optical storage properties of thin azobenzene side-chain polyester films were examined by polarization holographic measurements. The new amorphous polyester film is the candidate material for the purpose of rewritable holographic memory system. Temporal formation of anisotropic and topographic...... and erasing was tested. The ability of azobenzene polyester for rewriting was found satisfactory after many writing-erasing cycles....

  15. Partial Order Infinitary Term Rewriting and Böhm Trees

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2010-01-01

    We investigate an alternative model of infinitary term rewriting. Instead of a metric, a partial order on terms is employed to formalise (strong) convergence. We compare this partial order convergence of orthogonal term rewriting systems to the usual metric convergence of the corresponding Böhm e...

  16. Higher-Order Aberrations in Myopic Eyes

    Directory of Open Access Journals (Sweden)

    Farid Karimian

    2010-01-01

    Full Text Available Purpose: To evaluate the correlation between refractive error and higher-order aberrations (HOAs in patients with myopic astigmatism. Methods: HOAs were measured using the Zywave II aberrometer over a 6 mm pupil. Correlations between HOAs and myopia, astigmatism, and age were analyzed. Results: One hundred and twenty-six eyes of 63 subjects with mean age of 26.4±5.9 years were studied. Mean spherical equivalent refractive error and refractive astigmatism were -4.94±1.63 D and 0.96±1.06 D, respectively. The most common higher-order aberration was primary horizontal trefoil with mean value of 0.069±0.152 μm followed by spherical aberration (-0.064±0.130 μm and primary vertical coma (-0.038±0.148 μm. As the order of aberration increased from third to fifth, its contribution to total HOA decreased: 53.9% for third order, 31.9% for fourth order, and 14.2% for fifth order aberrations. Significant correlations were observed between spherical equivalent refractive error and primary horizontal coma (R=0.231, P=0.022, and root mean square (RMS of spherical aberration (R=0.213, P=0.031; between astigmatism and RMS of total HOA (R=0.251, P=0.032, RMS of fourth order aberration (R=0.35, P<0.001, and primary horizontal coma (R=0.314, P=0.004. Spherical aberration (R=0.214, P=0.034 and secondary vertical coma (R=0.203, P=0.031 significantly increased with age. Conclusion: Primary horizontal trefoil, spherical aberration and primary vertical coma are the predominant higher-order aberrations in eyes with myopic astigmatism.

  17. Extending CASL with Higher-order Functions

    DEFF Research Database (Denmark)

    Haxthausen, Anne; Krieg-Brückner, Bernd; Mossakowski, Till

    1998-01-01

    We present a proposal for the design of the higher-order extension of CASL. For each design step, we have tried to find the best of several possible alternatives, give a motivation for the preferred alternative and argue why the other alternatives are not taken. This note discusses function spaces......, product types, partial functions, predicates, subsorting, signature morphisms and \\-abstraction. A forthcoming note will be devoted to polymorphism, type constructors and dependent types. A companion note, replacing L-2, will explain the formal details of the proposal made in this note....

  18. Higher-Order Gauss-Bonnet Cosmology

    CERN Document Server

    Capozziello, Salvatore; Makarenko, Andrey N

    2014-01-01

    We study cosmological models derived from higher-order Gauss-Bonnet gravity $F(R,G)$ by using the Lagrange multiplier approach without assuming the presence of additional fields with the exception of standard perfect fluid matter. The presence of Lagrange multipliers reduces the number of allowed solutions. We need to introduce compatibility conditions of the FRW equations, which impose strict restrictions on the metric or require the introduction of additional exotic matter. Several classes of $F(R,G)$ models are generated and discussed.

  19. Higher Order Equations and Constituent Fields

    Science.gov (United States)

    Barci, D. G.; Bollini, C. G.; Oxman, L. E.; Rocca, M.

    We consider a simple wave equation of fourth degree in the D'Alembertian operator. It contains the main ingredients of a general Lorentz-invariant higher order equation, namely, a normal bradyonic sector, a tachyonic state and a pair of complex conjugate modes. The propagators are respectively the Feynman causal function and three Wheeler-Green functions (half-advanced and half-retarded). The latter are Lorentz-invariant and consistent with the elimination of tachyons and complex modes from free asymptotic states. We also verify the absence of absorptive parts from convolutions involving Wheeler propagators.

  20. Adaptive filtering using Higher Order Statistics (HOS

    Directory of Open Access Journals (Sweden)

    Abdelghani Manseur

    2012-03-01

    Full Text Available The performed job, in this study, consists in studying adaptive filters and higher order statistics (HOS to ameliorate their performances, by extension of linear case to non linear filters via Volterra series. This study is, principally, axed on: „ Choice of the adaptation step and convergence conditions. „ Convergence rate. „ Adaptive variation of the convergence factor, according to the input signal. The obtained results, with real signals, have shown computationally efficient and numerically stable algorithms for adaptive nonlinear filtering while keeping relatively simple computational complexity.

  1. Simulation and Verification of Synchronous Set Relations in Rewriting Logic

    Science.gov (United States)

    Rocha, Camilo; Munoz, Cesar A.

    2011-01-01

    This paper presents a mathematical foundation and a rewriting logic infrastructure for the execution and property veri cation of synchronous set relations. The mathematical foundation is given in the language of abstract set relations. The infrastructure consists of an ordersorted rewrite theory in Maude, a rewriting logic system, that enables the synchronous execution of a set relation provided by the user. By using the infrastructure, existing algorithm veri cation techniques already available in Maude for traditional asynchronous rewriting, such as reachability analysis and model checking, are automatically available to synchronous set rewriting. The use of the infrastructure is illustrated with an executable operational semantics of a simple synchronous language and the veri cation of temporal properties of a synchronous system.

  2. Enhanced higher order parametric x radiation production

    Science.gov (United States)

    Dinova, Kay L.

    1992-12-01

    This thesis examines parametric x-radiation (PXR) which is the Bragg scattering of the virtual photons associated with the Coulomb field of relativistic charged particle from the atomic planes of a crystal. Higher order parametric x-radiation from the (002) planes of a thick mosaic graphite crystal have been observed. The raw PXR data was collected using a SiLi detector and a Pulse Height Analyzer (PHA) software program. The data was corrected for various effects including attenuation, detector drift, and efficiency. The absolute number of photons per electron was obtained by using the fluorescent x-ray yield from a tin foil backing on the graphite crystal to determine the LINAC current. The number of photons per electron observed greatly exceeds the expected values. Comparison of the ratio of intensity of a given order to the first order I(n)/I(I) to the theoretical ratio shows that the ratios increase with order. Not only is the absolute intensity greater than expected, but the higher orders (compared to the first order) are larger than expected. Lastly, the intensity for various crystal angle orientations and a fixed detector angle was measured.

  3. Higher-order discrete variational problems with constraints

    Science.gov (United States)

    Colombo, Leonardo; Martín de Diego, David; Zuccalli, Marcela

    2013-09-01

    An interesting family of geometric integrators for Lagrangian systems can be defined using discretizations of the Hamilton's principle of critical action. This family of geometric integrators is called variational integrators. In this paper, we derive new variational integrators for higher-order Lagrangian mechanical system subjected to higher-order constraints. From the discretization of the variational principles, we show that our methods are automatically symplectic and, in consequence, with a very good energy behavior. Additionally, the symmetries of the discrete Lagrangian imply that momentum is conserved by the integrator. Moreover, we extend our construction to variational integrators where the Lagrangian is explicitly time-dependent. Finally, some motivating applications of higher-order problems are considered; in particular, optimal control problems for explicitly time-dependent underactuated systems and an interpolation problem on Riemannian manifolds.

  4. Thermodynamic study of the ternary mixed electrolyte (NaCl + NiCl{sub 2} + H{sub 2}O) system: Application of Pitzer model with higher-order electrostatic effects

    Energy Technology Data Exchange (ETDEWEB)

    Ghalami-Choobar, Bahram, E-mail: B-Ghalami@guilan.ac.i [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 19141, Rasht (Iran, Islamic Republic of)

    2011-06-15

    Research highlights: The thermodynamic properties of the ternary mixed electrolyte system (NaCl + NiCl{sub 2} + H{sub 2}O), by including the effects of higher-order electrostatic terms, are reported. The new self made ion selective electrodes have been used to determine the thermodynamic properties. The emf measurements have been performed on the entire range of total ionic strengths from 0.001 to 4.0 mol kg{sup -1}. The Pitzer model has been used to the thermodynamic properties correlation by including the effects of higher-order electrostatic terms. - Abstract: In this work, the thermodynamic properties of the ternary mixed electrolyte system (NaCl + NiCl{sub 2} + H{sub 2}O), using the potentiometric method, are reported. The potentiometric measurements were carried out on the galvanic cell without liquid junction of the type: Na-ISE/NaCl (m{sub 1}), NiCl{sub 2} (m{sub 2}), H{sub 2}O/Ag-AgCl over total ionic strengths from (0.001 to 4.000) mol {center_dot} kg{sup -1}. A different series of the salt molality ratios r(r=m{sub NaCl}/m{sub NiCl{sub 2}}=2.5,5.0,7.5,10.0) and pure NaCl were used for the measurement at T = 298.2 K. The results obtained were interpreted by using Pitzer ion-interaction model. The Pitzer mixing parameters have been evaluated for the system by including the effects of higher-order electrostatic terms. The Pitzer model is satisfactory and adequate for the description of our aqueous system. Furthermore, the parameters obtained with the Pitzer model were used to calculate the values of the mean activity coefficients of NiCl{sub 2}, the osmotic coefficients, solvent activity and the excess Gibbs free energy for the whole series of the mixed electrolyte system that was studied.

  5. Operational semantics of term rewriting with priorities

    NARCIS (Netherlands)

    Pol, J.C. van de

    2008-01-01

    We study the semantics of term rewriting systems with rule priorities (PRS), as introduced in [1]. Three open problems posed in that paper are solved, by giving counter examples. Moreover, a class of executable PRSs is identified. A translation of PRSs into transition system specifications (TSS) is

  6. Focus and Higher-Order Unification

    CERN Document Server

    Gardent, C; Gardent, Claire; Kohlhase, Michael

    1996-01-01

    Pulman has shown that Higher--Order Unification (HOU) can be used to model the interpretation of focus. In this paper, we extend the unification--based approach to cases which are often seen as a test--bed for focus theory: utterances with multiple focus operators and second occurrence expressions. We then show that the resulting analysis favourably compares with two prominent theories of focus (namely, Rooth's Alternative Semantics and Krifka's Structured Meanings theory) in that it correctly generates interpretations which these alternative theories cannot yield. Finally, we discuss the formal properties of the approach and argue that even though HOU need not terminate, for the class of unification--problems dealt with in this paper, HOU avoids this shortcoming and is in fact computationally tractable.

  7. Higher order modes in photonic crystal slabs.

    Science.gov (United States)

    Gansch, Roman; Kalchmair, Stefan; Detz, Hermann; Andrews, Aaron M; Klang, Pavel; Schrenk, Werner; Strasser, Gottfried

    2011-08-15

    We present a detailed investigation of higher order modes in photonic crystal slabs. In such structures the resonances exhibit a blue-shift compared to an ideal two-dimensional photonic crystal, which depends on the order of the slab mode and the polarization. By fabricating a series of photonic crystal slab photo detecting devices, with varying ratios of slab thickness to photonic crystal lattice constant, we are able to distinguish between 0th and 1st order slab modes as well as the polarization from the shift of resonances in the photocurrent spectra. This method complements the photonic band structure mapping technique for characterization of photonic crystal slabs. © 2011 Optical Society of America

  8. Rewriting the Genetic Code.

    Science.gov (United States)

    Mukai, Takahito; Lajoie, Marc J; Englert, Markus; Söll, Dieter

    2017-09-08

    The genetic code-the language used by cells to translate their genomes into proteins that perform many cellular functions-is highly conserved throughout natural life. Rewriting the genetic code could lead to new biological functions such as expanding protein chemistries with noncanonical amino acids (ncAAs) and genetically isolating synthetic organisms from natural organisms and viruses. It has long been possible to transiently produce proteins bearing ncAAs, but stabilizing an expanded genetic code for sustained function in vivo requires an integrated approach: creating recoded genomes and introducing new translation machinery that function together without compromising viability or clashing with endogenous pathways. In this review, we discuss design considerations and technologies for expanding the genetic code. The knowledge obtained by rewriting the genetic code will deepen our understanding of how genomes are designed and how the canonical genetic code evolved.

  9. Japanese Exploration to Solar System Small Bodies: Rewriting a Planetary Formation Theory with Astromaterial Connection (Invited)

    Science.gov (United States)

    Yano, H.

    2013-12-01

    Three decades ago, Japan's deep space exploration started with Sakigake and Suisei, twin flyby probes to P/Halley. Since then, the Solar System small bodies have been one of focused destinations to the Japanese solar system studies even today. Only one year after the Halley armada launch, the very first meeting was held for an asteroid sample return mission at ISAS, which after 25 years, materialized as the successful Earth return of Hayabusa , an engineering verification mission for sample return from surfaces of an NEO for the first time in the history. Launched in 2003 and returned in 2010, Hayabusa became the first to visit a sub-km, rubble-pile potentially hazardous asteroid in near Earth space. Its returned samples solved S-type asteroid - ordinary chondrite paradox by proving space weathering evidences in sub-micron scale. Between the Halley missions and Hayabusa, SOCCER concept by M-V rocket was jointly studied between ISAS and NASA; yet it was not realized due to insufficient delta-V for intact capture by decelerating flyby/encounter velocity to a cometary coma. The SOCCER later became reality as Stardust, NASA Discovery mission for cometary coma dust sample return in1999-2006. Japan has collected the second largest collection of the Antarctic meteorites and micrometeorites of the world and asteromaterial scientists are eager to collaborate with space missions. Also Japan enjoyed a long history of collaborations between professional astronomers and high-end amateur observers in the area of observational studies of asteroids, comets and meteors. Having these academic foundations, Japan has an emphasis on programmatic approach to sample returns of Solar System small bodies in future prospects. The immediate follow-on to Hayabusa is Hayabusa-2 mission to sample return with an artificial impactor from 1999 JU3, a C-type NEO in 2014-2020. Following successful demonstration of deep space solar sail technique by IKAROS in 2010-2013, the solar power sail is a deep

  10. Infinitary Combinatory Reduction Systems

    DEFF Research Database (Denmark)

    Ketema, Jeroen; Simonsen, Jakob Grue

    2011-01-01

    We define infinitary Combinatory Reduction Systems (iCRSs), thus providing the first notion of infinitary higher-order rewriting. The systems defined are sufficiently general that ordinary infinitary term rewriting and infinitary ¿-calculus are special cases. Furthermore,we generalise a number...... of knownresults fromfirst-order infinitary rewriting and infinitary ¿-calculus to iCRSs. In particular, for fully-extended, left-linear iCRSs we prove the well-known compression property, and for orthogonal iCRSs we prove that (1) if a set of redexes U has a complete development, then all complete developments...

  11. Should evolutionary geneticists worry about higher-order epistasis?

    Science.gov (United States)

    Weinreich, Daniel M; Lan, Yinghong; Wylie, C Scott; Heckendorn, Robert B

    2013-12-01

    Natural selection drives evolving populations up the fitness landscape, the projection from nucleotide sequence space to organismal reproductive success. While it has long been appreciated that topographic complexities on fitness landscapes can arise only as a consequence of epistatic interactions between mutations, evolutionary genetics has mainly focused on epistasis between pairs of mutations. Here we propose a generalization to the classical population genetic treatment of pairwise epistasis that yields expressions for epistasis among arbitrary subsets of mutations of all orders (pairwise, three-way, etc.). Our approach reveals substantial higher-order epistasis in almost every published fitness landscape. Furthermore we demonstrate that higher-order epistasis is critically important in two systems we know best. We conclude that higher-order epistasis deserves empirical and theoretical attention from evolutionary geneticists.

  12. Higher-order modulation instability in nonlinear fiber optics.

    Science.gov (United States)

    Erkintalo, Miro; Hammani, Kamal; Kibler, Bertrand; Finot, Christophe; Akhmediev, Nail; Dudley, John M; Genty, Goëry

    2011-12-16

    We report theoretical, numerical, and experimental studies of higher-order modulation instability in the focusing nonlinear Schrödinger equation. This higher-order instability arises from the nonlinear superposition of elementary instabilities, associated with initial single breather evolution followed by a regime of complex, yet deterministic, pulse splitting. We analytically describe the process using the Darboux transformation and compare with experiments in optical fiber. We show how a suitably low frequency modulation on a continuous wave field induces higher-order modulation instability splitting with the pulse characteristics at different phases of evolution related by a simple scaling relationship. We anticipate that similar processes are likely to be observed in many other systems including plasmas, Bose-Einstein condensates, and deep water waves.

  13. Scintillations of higher order laser beams in anisotropic atmospheric turbulence.

    Science.gov (United States)

    Baykal, Yahya; Luo, Yujuan; Ji, Xiaoling

    2016-11-20

    The scintillation index of higher order laser beams is examined when such beams propagate in anisotropic atmospheric turbulence. Anisotropy is introduced through non-Kolmogorov atmospheric turbulence. The scintillation index results are obtained by employing the Rytov method solution; thus the results are valid for weak anisotropic atmospheric turbulence and for horizontal links. Variations in the scintillations are shown for various higher order laser modes against the changes in the optical source size, power law exponent of anisotropic non-Kolmogorov spectrum, anisotropic factors, and link length. Our results can be used in the design of optical wireless communication systems used between airplanes.

  14. Aspects of general higher-order gravities

    CERN Document Server

    Bueno, Pablo; Min, Vincent S; Visser, Manus R

    2016-01-01

    We study several aspects of higher-order gravities constructed from general contractions of the Riemann tensor and the metric in arbitrary dimensions. First, we use the fast-linearization procedure presented in arXiv:1607.06463 to obtain the equations satisfied by the metric perturbation modes on a maximally symmetric background in the presence of matter and to classify $\\mathcal{L}($Riemann$)$ theories according to their spectrum. Then, we linearize all theories up to quartic order in curvature and use this result to construct quartic versions of Einsteinian cubic gravity (ECG). In addition, we show that the most general cubic gravity constructed in a dimension-independent way and which does not propagate the ghost-like spin-2 mode (but can propagate the scalar) is a linear combination of $f($Lovelock$)$ invariants, plus the ECG term, plus a New ghost-free gravity term. Next, we construct the generalized Newton potential and the Post-Newtonian parameter $\\gamma$ for general $\\mathcal{L}($Riemann$)$ gravities...

  15. 多输入多输出非线性不确定系统连续高阶滑模控制%Continuous higher-order sliding mode control for multi-input multi-output nonlinear uncertain system

    Institute of Scientific and Technical Information of China (English)

    刘向杰; 韩耀振

    2016-01-01

    This paper proposes a new continuous higher-order sliding mode control scheme for a class of MIMO nonlin-ear uncertain system. After implemented state feedback control, higher-order sliding mode control problem of the original uncertain nonlinear system is equivalently transformed into finite time stability problem of multivariable uncertain integror chains. A finite time continuous control law is firstly employed to guarantee rapid convergence of system states and finite time stabilization of nominal integral chain system, then multivariable non-coupling super-twisting algorithm is designed to overcome system uncertainties and achieve robustness. Finally, the whole control effect is continuous and high frequency chattering phenomenon of sliding mode is greatly weakened. Finite time stability of the closed loop system is proved strict-ly based on quadratic Lyapunov function. Examples concerning finite-time stabilization of a third order uncertain system and the hovercraft circular trajectory tracking are simulated respectively to verify the effectiveness and the robustness of the proposed approach.%针对一类MIMO非线性不确定系统,提出一种新的连续高阶滑模控制算法。引入状态反馈使得系统高阶滑模控制问题等效转换为多变量不确定积分链的有限时间稳定问题,首先针对标称系统设计有限时间到达连续控制律,实现系统状态快速收敛,然后采用多变量非解耦形式超螺旋算法克服系统不确定性,实现鲁棒性,最终使得系统控制作用连续、滑模抖振得以大大抑制。基于二次型Lyapunov函数证明系统的有限时间稳定性。针对三阶不确定系统有限时间稳定和气垫船圆形航迹跟踪问题分别进行了仿真,验证了所提算法的有效性、鲁棒性。

  16. A Rewriting Logic Approach to Type Inference

    Science.gov (United States)

    Ellison, Chucky; Şerbănuţă, Traian Florin; Roşu, Grigore

    Meseguer and Roşu proposed rewriting logic semantics (RLS) as a programing language definitional framework that unifies operational and algebraic denotational semantics. RLS has already been used to define a series of didactic and real languages, but its benefits in connection with defining and reasoning about type systems have not been fully investigated. This paper shows how the same RLS style employed for giving formal definitions of languages can be used to define type systems. The same term-rewriting mechanism used to execute RLS language definitions can now be used to execute type systems, giving type checkers or type inferencers. The proposed approach is exemplified by defining the Hindley-Milner polymorphic type inferencer mathcal{W} as a rewrite logic theory and using this definition to obtain a type inferencer by executing it in a rewriting logic engine. The inferencer obtained this way compares favorably with other definitions or implementations of mathcal{W}. The performance of the executable definition is within an order of magnitude of that of highly optimized implementations of type inferencers, such as that of OCaml.

  17. Multi-machine power system excitation control based on continuous higher-order sliding mode%基于连续高阶模滑的多机电力系统励磁控制

    Institute of Scientific and Technical Information of China (English)

    刘向杰; 韩耀振

    2016-01-01

    A continuous higher-order sliding mode excitation control strategy was proposed for improving transient sta-bility of multi-machine power system.Each power angle deviation was chosen as sliding variable.Higher-order sliding mode control for nonlinear and uncertain multi-machine power system was converted to finite time stability problem of uncertain integral chain.The controller was composed of geometric homogeneous continuous control law and second-or-der sliding mode super-twisting algorithm to achieve finite time convergence and conquer system uncertainties.The de-rivatives of power angles were estimated by so-called exact robust differentiator.Finite time stabilization of closed-loop system was theoretically proved.The proposed excitation control scheme could stabilize terminal voltage and enhance transient stability effectively.Simulation results for a three-machine system verified the validity of the proposed control method.%为了提高多机电力系统暂态稳定性,提出一种连续高阶滑模励磁控制策略。各发电机功角偏差为滑模变量,把具有非线性和不确定性多机电力系统的高阶滑模控制转化为不确定积分链系统的有限时间稳定问题,控制器结合几何齐次连续控制律和二阶滑模超螺旋算法,实现系统状态有限时间收敛,克服系统未建模动态、测量误差和外部扰动等不确定性,利用精确鲁棒微分器观测功角微分,理论分析证明了闭环系统的有限时间稳定。所设计高阶滑模励磁控制器能够保持机端电压稳定,并能有效提高电力系统的暂态稳定性。针对3机系统的仿真结果验证了该控制方法的有效性。

  18. An Algorithm for Higher Order Hopf Normal Forms

    Directory of Open Access Journals (Sweden)

    A.Y.T. Leung

    1995-01-01

    Full Text Available Normal form theory is important for studying the qualitative behavior of nonlinear oscillators. In some cases, higher order normal forms are required to understand the dynamic behavior near an equilibrium or a periodic orbit. However, the computation of high-order normal forms is usually quite complicated. This article provides an explicit formula for the normalization of nonlinear differential equations. The higher order normal form is given explicitly. Illustrative examples include a cubic system, a quadratic system and a Duffing–Van der Pol system. We use exact arithmetic and find that the undamped Duffing equation can be represented by an exact polynomial differential amplitude equation in a finite number of terms.

  19. Rewriting the language of creativity

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre

    2013-01-01

    For the past 5 decades the psychology of creativity has been influenced by what is known as the 4 P's of creative expression: person, process, product, and press. This conceptual schema, initially proposed by Rhodes (1961), helped researchers structure their thinking about the phenomenon. However......, it also supported an individualistic, static, and oftentimes disjointed vision of creativity. The present article aims to rewrite this fundamental language of the discipline by using terms that explicitly endorse a systemic, contextual, and dynamic approach. The 5 A's framework—actor, action, artifact......, audience, affordances—is grounded in current literature from sociocultural and ecological psychology as well as theories of the distributed mind and tries to achieve a more comprehensive and unitary perspective on creativity. Several theoretical, methodological, and practical implications are considered....

  20. The period functions' higher order derivatives

    CERN Document Server

    Sabatini, Marco

    2012-01-01

    We prove a formula for the $n$-th derivative of the period function $T$ in a period annulus of a planar differential system. For $n = 1$, we obtain Freire, Gasull and Guillamon formula for the period's first derivative \\cite{FGG}. We apply such a result to hamiltonian systems with separable variables and other systems. We give some sufficient conditions for the period function of conservative second order O.D.E.'s to be convex.

  1. A Modular Rewriting Semantics for CML

    DEFF Research Database (Denmark)

    Chalub, Fabricio; Braga, Christiano de Oliveira

    2004-01-01

    This paper presents a modular rewriting semantics (MRS) specification for Reppy's Concurrent ML (CML), based on Peter Mosses' modular structural operational semantics specification for CML. A modular rewriting semantics specification for a programming language is a rewrite theory in rewriting log...

  2. Modes of Convergence for Term Graph Rewriting

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2011-01-01

    Term graph rewriting provides a simple mechanism to finitely represent restricted forms of infinitary term rewriting. The correspondence between infinitary term rewriting and term graph rewriting has been studied to some extent. However, this endeavour is impaired by the lack of an appropriate co...

  3. Higher-order Brunnian structures and possible physical realizations

    DEFF Research Database (Denmark)

    A. Baas, Nils; V. Fedorov, D.; S. Jensen, A.

    2014-01-01

    to the binding of systems in nature. It now appears that recent generalization to higher order Brunnian structures may potentially be realized as laboratory made or naturally occurring systems. With the binding energy as measure, we discuss possibilities of physical realization in nuclei, cold atoms......, and condensed matter systems. Appearance is not excluded. However, both the form and the strengths of the interactions must be rather special. The most promising subfields for present searches would be in cold atoms because of external control of effective interactions, or perhaps in condensed-matter systems...

  4. Speckle reduction via higher order total variation approach.

    Science.gov (United States)

    Wensen Feng; Hong Lei; Yang Gao

    2014-04-01

    Multiplicative noise (also known as speckle) reduction is a prerequisite for many image-processing tasks in coherent imaging systems, such as the synthetic aperture radar. One approach extensively used in this area is based on total variation (TV) regularization, which can recover significantly sharp edges of an image, but suffers from the staircase-like artifacts. In order to overcome the undesirable deficiency, we propose two novel models for removing multiplicative noise based on total generalized variation (TGV) penalty. The TGV regularization has been mathematically proven to be able to eliminate the staircasing artifacts by being aware of higher order smoothness. Furthermore, an efficient algorithm is developed for solving the TGV-based optimization problems. Numerical experiments demonstrate that our proposed methods achieve state-of-the-art results, both visually and quantitatively. In particular, when the image has some higher order smoothness, our methods outperform the TV-based algorithms.

  5. Dispersion Management with Higher Order Mode Fibers

    Institute of Scientific and Technical Information of China (English)

    Siddharth Ramachandran

    2003-01-01

    Dispersion compensation with few-mode fibers is emerging as a promising technique that can provide full dispersion and dispersion-slope compensation. The inherent modal path diversity of these fibers allows implementation of static as well as tunable dispersion management schemes. In addition, the low nonlinearityof this technology can improve system OSNR, leading to enhancements in transmission distances.

  6. Dispersion Management with Higher Order Mode Fibers

    Institute of Scientific and Technical Information of China (English)

    Siddharth; Ramachandran

    2003-01-01

    Dispersion compensation with few-mode fibers is emerging as a promising technique that can provide full dispersion and dispersion-slope compensation. The inherent modal path diversity of these fibers allows implementation of static as well as tunable dispersion management schemes. In addition, the low non-linearity of this technology can improve system OSNR, leading to enhancements in transmission distances.

  7. Higher-Order and Symbolic Computation

    DEFF Research Database (Denmark)

    Danvy, Olivier; Mason, Ian

    2008-01-01

    HOL is a logic of total functions, one must explicitly address the termination of functions that are not primitive recursive. In "Flow-sensitive Type Systems and the Ambient Calculus," Torben Amtoft reports on what apperar to be the first type-based flow-sensitive topological analysis of ambient......-calculus programs, historically. The anaylsis determines the possible locations of ambients and mirrors the temporla sequencing of actions in the structure of types....

  8. Adaptive approximation of higher order posterior statistics

    KAUST Repository

    Lee, Wonjung

    2014-02-01

    Filtering is an approach for incorporating observed data into time-evolving systems. Instead of a family of Dirac delta masses that is widely used in Monte Carlo methods, we here use the Wiener chaos expansion for the parametrization of the conditioned probability distribution to solve the nonlinear filtering problem. The Wiener chaos expansion is not the best method for uncertainty propagation without observations. Nevertheless, the projection of the system variables in a fixed polynomial basis spanning the probability space might be a competitive representation in the presence of relatively frequent observations because the Wiener chaos approach not only leads to an accurate and efficient prediction for short time uncertainty quantification, but it also allows to apply several data assimilation methods that can be used to yield a better approximate filtering solution. The aim of the present paper is to investigate this hypothesis. We answer in the affirmative for the (stochastic) Lorenz-63 system based on numerical simulations in which the uncertainty quantification method and the data assimilation method are adaptively selected by whether the dynamics is driven by Brownian motion and the near-Gaussianity of the measure to be updated, respectively. © 2013 Elsevier Inc.

  9. A Modular Rewriting Semantics for CML

    DEFF Research Database (Denmark)

    Chalub, Fabricio; Braga, Christiano de Oliveira

    2004-01-01

    This paper presents a modular rewriting semantics (MRS) specification for Reppy's Concurrent ML (CML), based on Peter Mosses' modular structural operational semantics specification for CML. A modular rewriting semantics specification for a programming language is a rewrite theory in rewriting log...... of rewriting logic, and to verify CML programs using Maude's built-in LTL model checker. It is assumed that the reader is familiar with basic concepts of structural operational semantics and algebraic specifications....

  10. Higher order temporal finite element methods through mixed formalisms.

    Science.gov (United States)

    Kim, Jinkyu

    2014-01-01

    The extended framework of Hamilton's principle and the mixed convolved action principle provide new rigorous weak variational formalism for a broad range of initial boundary value problems in mathematical physics and mechanics. In this paper, their potential when adopting temporally higher order approximations is investigated. The classical single-degree-of-freedom dynamical systems are primarily considered to validate and to investigate the performance of the numerical algorithms developed from both formulations. For the undamped system, all the algorithms are symplectic and unconditionally stable with respect to the time step. For the damped system, they are shown to be accurate with good convergence characteristics.

  11. Higher-order conditioning and the retrosplenial cortex.

    Science.gov (United States)

    Todd, Travis P; Huszár, Roman; DeAngeli, Nicole E; Bucci, David J

    2016-09-01

    The retrosplenial cortex (RSC) is known to contribute to contextual and spatial learning and memory. This is consistent with its well-established connectivity; the RSC is located at the interface of visuo-spatial association areas and the parahippocampal-hippocampal memory system. However, the RSC also contributes to learning and memory for discrete cues. For example, both permanent lesions and temporary inactivation of the RSC have been shown to impair sensory preconditioning, a form of higher-order conditioning. The purpose of the present experiment was to examine the role of the RSC in a closely related higher-order conditioning paradigm: second-order conditioning. Sham and RSC lesioned rats received first-order conditioning in which one visual stimulus (V1) was paired with footshock and one visual stimulus (V2) was not. Following first-order conditioning, one auditory stimulus (A1) was then paired with V1 and a second auditory stimulus (A2) was paired with V2. Although lesions of the RSC impaired the first-order discrimination, they had no impact on the acquisition of second-order conditioning. Thus, the RSC does not appear necessary for acquisition/expression of second-order fear conditioning. The role of the RSC in higher-order conditioning, as well as a possible dissociation from the hippocampus, is discussed.

  12. Compiling CIL Rewriting Language for Multiprocessors

    Institute of Scientific and Technical Information of China (English)

    田新民; 王鼎兴; 等

    1994-01-01

    The high-level Conpiler Intermediate Language CIL is a general-purpose description language of parallel graph rewriting computational model intended for paralled implementation of declarative languages on multiprocessor systems.In this paper,we first outline a new Hybrid Execution Model(HEM) and corresponding parallel abstract machine PAM/TGR based on extended parallel Graph Rewriting Computational Model EGRCM for implementing CIL language on distributed memory multiprocessor systems.Then we focus on the compiling CIL language with various optimizing techniques such as pattern matching,rule indexing,node ordering and compile-time partial scheduling.The experimental results on a 16-node transputer Array demonstrates the effectiveness of our model and strategies.

  13. Strongly typed rewriting for coupled software transformation

    OpenAIRE

    Cunha, Alcino; Visser, J

    2006-01-01

    Coupled transformations occur in software evolution when multiple artifacts must be modified in such a way that they remain consistent with each other. An important example involves the coupled transformation of a data type, its instances, and the programs that consume or produce it. Previously, we have provided a formal treatment of transformation of the first two: data types and instances. The treatment involved the construction of type-safe, type-changing strategic rewrite systems. In this...

  14. Enhanced sensitivity at higher-order exceptional points.

    Science.gov (United States)

    Hodaei, Hossein; Hassan, Absar U; Wittek, Steffen; Garcia-Gracia, Hipolito; El-Ganainy, Ramy; Christodoulides, Demetrios N; Khajavikhan, Mercedeh

    2017-08-09

    Non-Hermitian degeneracies, also known as exceptional points, have recently emerged as a new way to engineer the response of open physical systems, that is, those that interact with the environment. They correspond to points in parameter space at which the eigenvalues of the underlying system and the corresponding eigenvectors simultaneously coalesce. In optics, the abrupt nature of the phase transitions that are encountered around exceptional points has been shown to lead to many intriguing phenomena, such as loss-induced transparency, unidirectional invisibility, band merging, topological chirality and laser mode selectivity. Recently, it has been shown that the bifurcation properties of second-order non-Hermitian degeneracies can provide a means of enhancing the sensitivity (frequency shifts) of resonant optical structures to external perturbations. Of particular interest is the use of even higher-order exceptional points (greater than second order), which in principle could further amplify the effect of perturbations, leading to even greater sensitivity. Although a growing number of theoretical studies have been devoted to such higher-order degeneracies, their experimental demonstration in the optical domain has so far remained elusive. Here we report the observation of higher-order exceptional points in a coupled cavity arrangement-specifically, a ternary, parity-time-symmetric photonic laser molecule-with a carefully tailored gain-loss distribution. We study the system in the spectral domain and find that the frequency response associated with this system follows a cube-root dependence on induced perturbations in the refractive index. Our work paves the way for utilizing non-Hermitian degeneracies in fields including photonics, optomechanics, microwaves and atomic physics.

  15. HIGHER ORDER MULTIVARIABLE NORLUND EULER-BERNOULLI POLYNOMIALS

    Institute of Scientific and Technical Information of China (English)

    刘国栋

    2002-01-01

    The definitions of higher order multivariable Norlund Euler polynomials and Norlund Bernoulli polynomials are presented and some of their important properties are expounded. Some identities involving recurrence sequences and higher order multivariable Norlund Euler-Bernoulli polynomials are established.

  16. Generalizations of Euler Numbers and Euler Numbers of Higher Order

    Institute of Scientific and Technical Information of China (English)

    LUOQiu-ming; QIFeng

    2005-01-01

    The purpose of this paper is to define the generalized Euler numbers and the generalized Euler numbers of higher order, their recursion formula and some properties were established, accordingly Euler numbers and Euler numbers of higher order were extended.

  17. Higher-orders in heavy quark processes within the LTD approach

    CERN Document Server

    Sborlini, German F R

    2016-01-01

    The computation of perturbative corrections to processes involving heavy quarks is crucial for the precision program of the LHC and future colliders. In this article, we describe a powerful approach to calculate higher-orders in QCD skipping the traditional subtraction method. Our proposal is based on the loop-tree duality (LTD) theorem, which allows to rewrite virtual contributions in terms of integrals over the real emission phase-space. Then, we proceed to combine both real and virtual contributions at the integrand level, obtaining regular expressions that can be numerically integrated in four space-time dimensions. In this way, we avoid dealing with complicated massive Feynman integrals and introducing infrared counter-terms. Some reference examples are explained, in order to exhibit the potential of our method.

  18. A Higher Order Godunov Method for Radiation Hydrodynamics: Radiation Subsystem

    CERN Document Server

    Sekora, Michael

    2009-01-01

    A higher order Godunov method for the radiation subsystem of radiation hydrodynamics is presented. A key ingredient of the method is the direct coupling of stiff source term effects to the hyperbolic structure of the system of conservation laws; it is composed of a predictor step that is based on Duhamel's principle and a corrector step that is based on Picard iteration. The method is second order accurate in both time and space, unsplit, asymptotically preserving, and uniformly well behaved from the photon free streaming (hyperbolic) limit through the weak equilibrium diffusion (parabolic) limit and to the strong equilibrium diffusion (hyperbolic) limit. Numerical tests demonstrate second order convergence across various parameter regimes.

  19. Modeling Human Behaviour with Higher Order Logic: Insider Threats

    DEFF Research Database (Denmark)

    Boender, Jaap; Ivanova, Marieta Georgieva; Kammuller, Florian

    2014-01-01

    In this paper, we approach the problem of modeling the human component in technical systems with a view on the difference between the use of model and theory in sociology and computer science. One aim of this essay is to show that building of theories and models for sociology can be compared...... it to the sociological process of logical explanation. As a case study on modeling human behaviour, we present the modeling and analysis of insider threats as a Higher Order Logic theory in Isabelle/HOL. We show how each of the three step process of sociological explanation can be seen in our modeling of insider’s state...

  20. Conceptualizing and Assessing Higher-Order Thinking in Reading

    Science.gov (United States)

    Afflerbach, Peter; Cho, Byeong-Young; Kim, Jong-Yun

    2015-01-01

    Students engage in higher-order thinking as they read complex texts and perform complex reading-related tasks. However, the most consequential assessments, high-stakes tests, are currently limited in providing information about students' higher-order thinking. In this article, we describe higher-order thinking in relation to reading. We provide a…

  1. Higher order statistical moment application for solar PV potential analysis

    Science.gov (United States)

    Basri, Mohd Juhari Mat; Abdullah, Samizee; Azrulhisham, Engku Ahmad; Harun, Khairulezuan

    2016-10-01

    Solar photovoltaic energy could be as alternative energy to fossil fuel, which is depleting and posing a global warming problem. However, this renewable energy is so variable and intermittent to be relied on. Therefore the knowledge of energy potential is very important for any site to build this solar photovoltaic power generation system. Here, the application of higher order statistical moment model is being analyzed using data collected from 5MW grid-connected photovoltaic system. Due to the dynamic changes of skewness and kurtosis of AC power and solar irradiance distributions of the solar farm, Pearson system where the probability distribution is calculated by matching their theoretical moments with that of the empirical moments of a distribution could be suitable for this purpose. On the advantage of the Pearson system in MATLAB, a software programming has been developed to help in data processing for distribution fitting and potential analysis for future projection of amount of AC power and solar irradiance availability.

  2. Higher-Order Spectrum in Understanding Nonlinearity in EEG Rhythms

    Directory of Open Access Journals (Sweden)

    Cauchy Pradhan

    2012-01-01

    Full Text Available The fundamental nature of the brain's electrical activities recorded as electroencephalogram (EEG remains unknown. Linear stochastic models and spectral estimates are the most common methods for the analysis of EEG because of their robustness, simplicity of interpretation, and apparent association with rhythmic behavioral patterns in nature. In this paper, we extend the use of higher-order spectrum in order to indicate the hidden characteristics of EEG signals that simply do not arise from random processes. The higher-order spectrum is an extension Fourier spectrum that uses higher moments for spectral estimates. This essentially nullifies all Gaussian random effects, therefore, can reveal non-Gaussian and nonlinear characteristics in the complex patterns of EEG time series. The paper demonstrates the distinguishing features of bispectral analysis for chaotic systems, filtered noises, and normal background EEG activity. The bispectrum analysis detects nonlinear interactions; however, it does not quantify the coupling strength. The squared bicoherence in the nonredundant region has been estimated to demonstrate nonlinear coupling. The bicoherence values are minimal for white Gaussian noises (WGNs and filtered noises. Higher bicoherence values in chaotic time series and normal background EEG activities are indicative of nonlinear coupling in these systems. The paper shows utility of bispectral methods as an analytical tool in understanding neural process underlying human EEG patterns.

  3. Higher-order techniques for some problems of nonlinear control

    Directory of Open Access Journals (Sweden)

    Sarychev Andrey V.

    2002-01-01

    Full Text Available A natural first step when dealing with a nonlinear problem is an application of some version of linearization principle. This includes the well known linearization principles for controllability, observability and stability and also first-order optimality conditions such as Lagrange multipliers rule or Pontryagin's maximum principle. In many interesting and important problems of nonlinear control the linearization principle fails to provide a solution. In the present paper we provide some examples of how higher-order methods of differential geometric control theory can be used for the study nonlinear control systems in such cases. The presentation includes: nonlinear systems with impulsive and distribution-like inputs; second-order optimality conditions for bang–bang extremals of optimal control problems; methods of high-order averaging for studying stability and stabilization of time-variant control systems.

  4. Higher-Order Cyclostationarity Detection for Spectrum Sensing

    Directory of Open Access Journals (Sweden)

    Julien Renard

    2010-01-01

    Full Text Available Recent years have shown a growing interest in the concept of Cognitive Radios (CRs, able to access portions of the electromagnetic spectrum in an opportunistic operating way. Such systems require efficient detectors able to work in low Signal-to-Noise Ratio (SNR environments, with little or no information about the signals they are trying to detect. Energy detectors are widely used to perform such blind detection tasks, but quickly reach the so-called SNR wall below which detection becomes impossible Tandra (2005. Cyclostationarity detectors are an interesting alternative to energy detectors, as they exploit hidden periodicities present in man-made signals, but absent in noise. Such detectors use quadratic transformations of the signals to extract the hidden sine-waves. While most of the literature focuses on the second-order transformations of the signals, we investigate the potential of higher-order transformations of the signals. Using the theory of Higher-Order Cyclostationarity (HOCS, we derive a fourth-order detector that performs similarly to the second-order ones to detect linearly modulated signals, at SNR around 0 dB, which may be used if the signals of interest do not exhibit second-order cyclostationarity. More generally this paper reviews the relevant aspects of the cyclostationary and HOCS theory, and shows their potential for spectrum sensing.

  5. Rewriting Constraint Models with Metamodels

    CERN Document Server

    Chenouard, Raphael; Soto, Ricardo

    2010-01-01

    An important challenge in constraint programming is to rewrite constraint models into executable programs calculat- ing the solutions. This phase of constraint processing may require translations between constraint programming lan- guages, transformations of constraint representations, model optimizations, and tuning of solving strategies. In this paper, we introduce a pivot metamodel describing the common fea- tures of constraint models including different kinds of con- straints, statements like conditionals and loops, and other first-class elements like object classes and predicates. This metamodel is general enough to cope with the constructions of many languages, from object-oriented modeling languages to logic languages, but it is independent from them. The rewriting operations manipulate metamodel instances apart from languages. As a consequence, the rewriting operations apply whatever languages are selected and they are able to manage model semantic information. A bridge is created between the metamode...

  6. Dependable software through higher-order strategic programming.

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Victor Lono (University of Nebraska at Omaha); Fraij, Fares (University of Texas at El Paso); Roach, Steve (University of Texas at El Paso)

    2004-03-01

    Program transformation is a restricted form of software construction that can be amenable to formal verification. When successful, the nature of the evidence provided by such a verification is considered strong and can constitute a major component of an argument that a high-consequence or safety-critical system meets its dependability requirements. This article explores the application of novel higher-order strategic programming techniques to the development of a portion of a class loader for a restricted implementation of the Java Virtual Machine (JVM). The implementation is called the SSP and is intended for use in high-consequence safety-critical embedded systems. Verification of the strategic program using ACL2 is also discussed.

  7. Higher Order Diffraction Characteristics of Fiber Bragg Grating

    Directory of Open Access Journals (Sweden)

    Sunita P. Ugale

    2013-02-01

    Full Text Available The effect of grating saturation on higher order diffraction characteristic of FBG is investigated by using Coupled mode theory. Grating saturation effects were considered in the index distribution model showing the significant influence on the coupling process and hence on the reflectivity characteristics of FBG. Maximum reflectivity curves for first and higher order diffraction of FBG are plotted for different values of saturation coefficient. The effect of change in length and change in refractive index are studied. The behavior of grating for higher order of diffraction is totally different than first order of diffraction. In saturated gratings, the higher order diffraction can be utilized for multiparameter sensing

  8. Adaptive Integral Method for Higher Order Method of Moments

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Meincke, Peter

    2008-01-01

    The adaptive integral method (AIM) is combined with the higher order method of moments (MoM) to solve integral equations. The technique takes advantage of the low computational complexity and memory requirements of the AIM and the reduced number of unknowns and higher order convergence of higher...... order basis functions. The classical AIM is appropriately modified to allow larger discretization elements and, consequently, higher basis function expansion orders. Numerical examples based on the higher order hierarchical Legendre basis functions show the advantages of the proposed technique over...... the classical AIM based on low-order basis functions in terms of memory and computational time....

  9. PHASE EQUILIBRIA INVESTIGATIONS OF BINARY, TERNARY, AND HIGHER ORDER SYSTEMS. PART 2. EFFECT OF RHENIUM AND ALUMINUM ADDITIONS ON THE METAL-RICH EQUILIBRIA IN THE TITANIUM-MOLYBDENIUM-CARBON AND TITANIUM-NIOBIUM-CARBON SYSTEMS

    Science.gov (United States)

    The solid state phase equilibria of the metal-rich regions of the Titanium-Molybdenum-Carbon and Titanium-Niobium-Carbon systems with up to 12 At...Rhenium and 10 At.% Aluminum additions, respectively, have been determined on hot pressed, heat treated, and in part arc melted alloys. The phase ... equilibria in the metal-rich regions, with these additions, is practically unchanged over that of the ternary Titanium-Molybdenum-Carbon and Titanium

  10. A higher-order theory of emotional consciousness.

    Science.gov (United States)

    LeDoux, Joseph E; Brown, Richard

    2017-03-07

    Emotional states of consciousness, or what are typically called emotional feelings, are traditionally viewed as being innately programmed in subcortical areas of the brain, and are often treated as different from cognitive states of consciousness, such as those related to the perception of external stimuli. We argue that conscious experiences, regardless of their content, arise from one system in the brain. In this view, what differs in emotional and nonemotional states are the kinds of inputs that are processed by a general cortical network of cognition, a network essential for conscious experiences. Although subcortical circuits are not directly responsible for conscious feelings, they provide nonconscious inputs that coalesce with other kinds of neural signals in the cognitive assembly of conscious emotional experiences. In building the case for this proposal, we defend a modified version of what is known as the higher-order theory of consciousness.

  11. A higher-order theory of emotional consciousness

    Science.gov (United States)

    LeDoux, Joseph E.; Brown, Richard

    2017-01-01

    Emotional states of consciousness, or what are typically called emotional feelings, are traditionally viewed as being innately programmed in subcortical areas of the brain, and are often treated as different from cognitive states of consciousness, such as those related to the perception of external stimuli. We argue that conscious experiences, regardless of their content, arise from one system in the brain. In this view, what differs in emotional and nonemotional states are the kinds of inputs that are processed by a general cortical network of cognition, a network essential for conscious experiences. Although subcortical circuits are not directly responsible for conscious feelings, they provide nonconscious inputs that coalesce with other kinds of neural signals in the cognitive assembly of conscious emotional experiences. In building the case for this proposal, we defend a modified version of what is known as the higher-order theory of consciousness. PMID:28202735

  12. Recognition of higher order patterns in proteins: immunologic kernels.

    Directory of Open Access Journals (Sweden)

    Robert D Bremel

    Full Text Available By applying analysis of the principal components of amino acid physical properties we predicted cathepsin cleavage sites, MHC binding affinity, and probability of B-cell epitope binding of peptides in tetanus toxin and in ten diverse additional proteins. Cross-correlation of these metrics, for peptides of all possible amino acid index positions, each evaluated in the context of a ±25 amino acid flanking region, indicated that there is a strongly repetitive pattern of short peptides of approximately thirty amino acids each bounded by cathepsin cleavage sites and each comprising B-cell linear epitopes, MHC-I and MHC-II binding peptides. Such "immunologic kernel" peptides comprise all signals necessary for adaptive immunologic cognition, response and recall. The patterns described indicate a higher order spatial integration that forms a symbolic logic coordinating the adaptive immune system.

  13. Solution of volume-surface integral equations using higher-order hierarchical Legendre basis functions

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav

    2007-01-01

    is applied to transform the VSIE into a system of linear equations. The higher-order MoM provides significant reduction in the number of unknowns in comparison with standard MoM formulations using low-order basis functions, such as RWG functions. Due to the orthogonal nature of the higher-order Legendre......The problem of electromagnetic scattering by composite metallic and dielectric objects is solved using the coupled volume-surface integral equation (VSIE). The method of moments (MoM) based on higher-order hierarchical Legendre basis functions and higher-order curvilinear geometrical elements...

  14. Visualizing Higher Order Finite Elements: FY05 Yearly Report.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David; Pebay, Philippe Pierre

    2005-11-01

    This report contains an algorithm for decomposing higher-order finite elementsinto regions appropriate for isosurfacing and proves the conditions under which thealgorithm will terminate. Finite elements are used to create piecewise polynomialapproximants to the solution of partial differential equations for which no analyticalsolution exists. These polynomials represent fields such as pressure, stress, and mo-mentim. In the past, these polynomials have been linear in each parametric coordinate.Each polynomial coefficient must be uniquely determined by a simulation, and thesecoefficients are called degrees of freedom. When there are not enough degrees of free-dom, simulations will typically fail to produce a valid approximation to the solution.Recent work has shown that increasing the number of degrees of freedom by increas-ing the order of the polynomial approximation (instead of increasing the number offinite elements, each of which has its own set of coefficients) can allow some typesof simulations to produce a valid approximation with many fewer degrees of freedomthan increasing the number of finite elements alone. However, once the simulation hasdetermined the values of all the coefficients in a higher-order approximant, tools donot exist for visual inspection of the solution.This report focuses on a technique for the visual inspection of higher-order finiteelement simulation results based on decomposing each finite element into simplicialregions where existing visualization algorithms such as isosurfacing will work. Therequirements of the isosurfacing algorithm are enumerated and related to the placeswhere the partial derivatives of the polynomial become zero. The original isosurfacingalgorithm is then applied to each of these regions in turn.3 AcknowledgementThe authors would like to thank David Day and Louis Romero for their insight into poly-nomial system solvers and the LDRD Senior Council for the opportunity to pursue thisresearch. The authors were

  15. On the fractional counterpart of the higher-order equations

    CERN Document Server

    D'Ovidio, Mirko

    2011-01-01

    In this work we study the solutions to some fractional higher-order equations. Special cases in which time-fractional derivatives take integer values are also examined and the explicit solutions are presented. Such solutions can be expressed by means of the transition laws of stable subordinators and their inverse processes. In particular we establish connections between fractional and higher-order equations.

  16. Higher Order Thinking: Definition, Meaning and Instructional Approaches.

    Science.gov (United States)

    Thomas, Ruth G., Ed.

    This publication shares current thinking, research, and practice in the area of higher order thinking skills with home economics educators, including teachers, supervisors, and teacher educators. The first three articles provide general discussions of thinking skills. They are "Introduction" (Ruth Pestle); "Can Higher Order Thinking…

  17. Numbers of Subnormal Solutions for Higher Order Periodic Differential Equations

    Institute of Scientific and Technical Information of China (English)

    Zong Xuan CHEN; Kwang Ho SHON

    2011-01-01

    In this paper,we estimate the number of subnormal solutions for higher order linear periodic differential equations,and estimate the growth of subnormal solutions and all other solutions.We also give a representation of subnormal solutions of a class of higher order linear periodic differential equations.

  18. Conservation Laws in Higher-Order Nonlinear Optical Effects

    CERN Document Server

    Kim, J; Shin, H J; Kim, Jongbae

    1999-01-01

    Conservation laws of the nonlinear Schrödinger equation are studied in the presence of higher-order nonlinear optical effects including the third-order dispersion and the self-steepening. In a context of group theory, we derive a general expression for infinitely many conserved currents and charges of the coupled higher-order nonlinear Schrödinger equation. The first few currents and charges are also presented explicitly. Due to the higher-order effects, conservation laws of the nonlinear Schrödinger equation are violated in general. The differences between the types of the conserved currents for the Hirota and the Sasa-Satsuma equations imply that the higher-order terms determine the inherent types of conserved quantities for each integrable cases of the higher-order nonlinear Schrödinger equation.

  19. Higher order factors of personality: do they exist?

    Science.gov (United States)

    Ashton, Michael C; Lee, Kibeom; Goldberg, Lewis R; de Vries, Reinout E

    2009-05-01

    Scales that measure the Big Five personality factors are often substantially intercorrelated. These correlations are sometimes interpreted as implying the existence of two higher order factors of personality. The authors show that correlations between measures of broad personality factors do not necessarily imply the existence of higher order factors and might instead be due to variables that represent same-signed blends of orthogonal factors. Therefore, the hypotheses of higher order factors and blended variables can only be tested with data on lower level personality variables that define the personality factors. The authors compared the higher order factor model and the blended variable model in three participant samples using the Big Five Aspect Scales, and found better fit for the latter model. In other analyses using the HEXACO Personality Inventory, they identified mutually uncorrelated markers of six personality factors. The authors conclude that correlations between personality factor scales can be explained without postulating any higher order dimensions of personality.

  20. Higher-order mode photonic crystal based nanofluidic sensor

    Science.gov (United States)

    Peng, Wang; Chen, Youping; Ai, Wu

    2017-01-01

    A higher-order photonic crystal (PC) based nanofluidic sensor, which worked at 532 nm, was designed and demonstrated. A systematical and detailed method for sculpturing a PC sensor for a given peak wavelength value (PWV) and specified materials was illuminated. It was the first time that the higher order mode was used to design PC based nanofluidic sensor, and the refractive index (RI) sensitivity of this sensor had been verified with FDTD simulation software from Lumerical. The enhanced electrical field of higher order mode structure was mostly confined in the channel area, where the enhance field is wholly interacting with the analytes in the channels. The comparison of RI sensitivity between fundamental mode and higher order mode shows the RI variation of higher order mode is 124.5 nm/RIU which is much larger than the fundamental mode. The proposed PC based nanofluidic structure pioneering a novel style for future optofluidic design.

  1. A Recurrence Relation Approach to Higher Order Quantum Superintegrability

    Directory of Open Access Journals (Sweden)

    Ernie G. Kalnins

    2011-03-01

    Full Text Available We develop our method to prove quantum superintegrability of an integrable 2D system, based on recurrence relations obeyed by the eigenfunctions of the system with respect to separable coordinates. We show that the method provides rigorous proofs of superintegrability and explicit constructions of higher order generators for the symmetry algebra. We apply the method to 5 families of systems, each depending on a parameter k, including most notably the caged anisotropic oscillator, the Tremblay, Turbiner and Winternitz system and a deformed Kepler-Coulomb system, and we give proofs of quantum superintegrability for all rational values of k, new for 4 of these systems. In addition, we show that the explicit information supplied by the special function recurrence relations allows us to prove, for the first time in 4 cases, that the symmetry algebra generated by our lowest order symmetries closes and to determine the associated structure equations of the algebras for each k. We have no proof that our generating symmetries are of lowest possible order, but we have no counterexamples, and we are confident we can can always find any missing generators from our raising and lowering operator recurrences. We also get for free, one variable models of the action of the symmetry algebra in terms of difference operators. We describe how the Stäckel transform acts and show that it preserves the structure equations.

  2. Proceedings International Workshop on Strategies in Rewriting, Proving, and Programming

    CERN Document Server

    Kirchner, Hélène; 10.4204/EPTCS.44

    2010-01-01

    This volume contains selected papers from the proceedings of the First International Workshop on Strategies in Rewriting, Proving, and Programming (IWS 2010), which was held on July 9, 2010, in Edinburgh, UK. Strategies are ubiquitous in programming languages, automated deduction and reasoning systems. In the two communities of Rewriting and Programming on one side, and of Deduction and Proof engines (Provers, Assistants, Solvers) on the other side, workshops have been launched to make progress towards a deeper understanding of the nature of strategies, their descriptions, their properties, and their usage, in all kinds of computing and reasoning systems. Since more recently, strategies are also playing an important role in rewrite-based programming languages, verification tools and techniques like SAT/SMT engines or termination provers. Moreover strategies have come to be viewed more generally as expressing complex designs for control in computing, modeling, proof search, program transformation, and access c...

  3. Higher-order phase transitions on financial markets

    Science.gov (United States)

    Kasprzak, A.; Kutner, R.; Perelló, J.; Masoliver, J.

    2010-08-01

    Statistical and thermodynamic properties of the anomalous multifractal structure of random interevent (or intertransaction) times were thoroughly studied by using the extended continuous-time random walk (CTRW) formalism of Montroll, Weiss, Scher, and Lax. Although this formalism is quite general (and can be applied to any interhuman communication with nontrivial priority), we consider it in the context of a financial market where heterogeneous agent activities can occur within a wide spectrum of time scales. As the main general consequence, we found (by additionally using the Saddle-Point Approximation) the scaling or power-dependent form of the partition function, Z(q'). It diverges for any negative scaling powers q' (which justifies the name anomalous) while for positive ones it shows the scaling with the general exponent τ(q'). This exponent is the nonanalytic (singular) or noninteger power of q', which is one of the pilar of higher-order phase transitions. In definition of the partition function we used the pausing-time distribution (PTD) as the central one, which takes the form of convolution (or superstatistics used, e.g. for describing turbulence as well as the financial market). Its integral kernel is given by the stretched exponential distribution (often used in disordered systems). This kernel extends both the exponential distribution assumed in the original version of the CTRW formalism (for description of the transient photocurrent measured in amorphous glassy material) as well as the Gaussian one sometimes used in this context (e.g. for diffusion of hydrogen in amorphous metals or for aging effects in glasses). Our most important finding is the third- and higher-order phase transitions, which can be roughly interpreted as transitions between the phase where high frequency trading is most visible and the phase defined by low frequency trading. The specific order of the phase transition directly depends upon the shape exponent α defining the stretched

  4. Teaching Higher Order Thinking in the Introductory MIS Course: A Model-Directed Approach

    Science.gov (United States)

    Wang, Shouhong; Wang, Hai

    2011-01-01

    One vision of education evolution is to change the modes of thinking of students. Critical thinking, design thinking, and system thinking are higher order thinking paradigms that are specifically pertinent to business education. A model-directed approach to teaching and learning higher order thinking is proposed. An example of application of the…

  5. Teaching Higher Order Thinking in the Introductory MIS Course: A Model-Directed Approach

    Science.gov (United States)

    Wang, Shouhong; Wang, Hai

    2011-01-01

    One vision of education evolution is to change the modes of thinking of students. Critical thinking, design thinking, and system thinking are higher order thinking paradigms that are specifically pertinent to business education. A model-directed approach to teaching and learning higher order thinking is proposed. An example of application of the…

  6. Higher order statistical frequency domain decomposition for operational modal analysis

    Science.gov (United States)

    Nita, G. M.; Mahgoub, M. A.; Sharyatpanahi, S. G.; Cretu, N. C.; El-Fouly, T. M.

    2017-02-01

    Experimental methods based on modal analysis under ambient vibrational excitation are often employed to detect structural damages of mechanical systems. Many of such frequency domain methods, such as Basic Frequency Domain (BFD), Frequency Domain Decomposition (FFD), or Enhanced Frequency Domain Decomposition (EFFD), use as first step a Fast Fourier Transform (FFT) estimate of the power spectral density (PSD) associated with the response of the system. In this study it is shown that higher order statistical estimators such as Spectral Kurtosis (SK) and Sample to Model Ratio (SMR) may be successfully employed not only to more reliably discriminate the response of the system against the ambient noise fluctuations, but also to better identify and separate contributions from closely spaced individual modes. It is shown that a SMR-based Maximum Likelihood curve fitting algorithm may improve the accuracy of the spectral shape and location of the individual modes and, when combined with the SK analysis, it provides efficient means to categorize such individual spectral components according to their temporal dynamics as coherent or incoherent system responses to unknown ambient excitations.

  7. Higher-order harmonics of general limited diffraction Bessel beams

    Science.gov (United States)

    Ding, De-Sheng; Huang, Jin-Huang

    2016-12-01

    In this paper, we extensively study the higher-order harmonic generation of the general limited diffraction m-th-order Bessel beam. The analysis is based on successive approximations of the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. Asymptotic expansions are presented for higher-order harmonic Bessel beams in near and far fields. The validity of asymptotic approximation is also analyzed. The higher-order harmonic of the Bessel beam with the lowest zero-order is taken as a special example. Project supported by the National Natural Science Foundation of China (Grant Nos. 11074038 and 11374051).

  8. Higher order SVD analysis for dynamic texture synthesis.

    Science.gov (United States)

    Costantini, Roberto; Sbaiz, Luciano; Süsstrunk, Sabine

    2008-01-01

    Videos representing flames, water, smoke, etc., are often defined as dynamic textures: "textures" because they are characterized by the redundant repetition of a pattern and "dynamic" because this repetition is also in time and not only in space. Dynamic textures have been modeled as linear dynamic systems by unfolding the video frames into column vectors and describing their trajectory as time evolves. After the projection of the vectors onto a lower dimensional space by a singular value decomposition (SVD), the trajectory is modeled using system identification techniques. Synthesis is obtained by driving the system with random noise. In this paper, we show that the standard SVD can be replaced by a higher order SVD (HOSVD), originally known as Tucker decomposition. HOSVD decomposes the dynamic texture as a multidimensional signal (tensor) without unfolding the video frames on column vectors. This is a more natural and flexible decomposition, since it permits us to perform dimension reduction in the spatial, temporal, and chromatic domain, while standard SVD allows for temporal reduction only. We show that for a comparable synthesis quality, the HOSVD approach requires, on average, five times less parameters than the standard SVD approach. The analysis part is more expensive, but the synthesis has the same cost as existing algorithms. Our technique is, thus, well suited to dynamic texture synthesis on devices limited by memory and computational power, such as PDAs or mobile phones.

  9. Demand-Driven Higher-Order Fixpoint Iteration

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    Our aim is to show that techniques from higher-order strictness analysis may be used as a general algorithmic principle in a functional programming language. Certain problems may be expressed as the search for the least solution that satisfy certain given properties. This is often done using some...... kind of fixpoint iteration. We will present a fixpoint operation that can be used for second-order functions and extend this to higher-order functions. The technique is based on using partial function graphs to represent higher-order objects. The main problem in finding fixpoints for higher......-order functions is to establish a notion of {\\em neededness} so as to restrict the iteration to those parts of the function that may influence the result. This is here done through a uniform extension of the domain of values with need information. The result is an iteration strategy which will terminate if base...

  10. Unambiguous formalism for higher order Lagrangian field theories

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Cedric M; De Leon, Manuel; De Diego, David MartIn [Instituto de Ciencias Matematicas, CSIC-UAM-UC3M-UCM, Serrano 123, 28006 Madrid (Spain); Vankerschaver, Joris [Control and Dynamical Systems, California Institute of Technology, CA (United States)], E-mail: cedricmc@imaff.cfmac.csic.es, E-mail: mdeleon@imaff.cfmac.csic.es, E-mail: d.martin@imaff.cfmac.csic.es, E-mail: jv@caltech.edu

    2009-11-27

    The aim of this paper is to propose an unambiguous intrinsic formalism for higher order field theories which avoids the arbitrariness in the generalization of the conventional description of field theories, and implies the existence of different Cartan forms and Legendre transformations. We propose a differential-geometric setting for the dynamics of a higher order field theory, based on the Skinner and Rusk formalism for mechanics. This approach incorporates aspects of both the Lagrangian and the Hamiltonian description, since the field equations are formulated using the Lagrangian on a higher order jet bundle and the canonical multisymplectic form on its affine dual. As both of these objects are uniquely defined, the Skinner-Rusk approach has the advantage that it does not suffer from the arbitrariness in conventional descriptions. The result is that we obtain a unique and global intrinsic version of the Euler-Lagrange equations for higher order field theories. Several examples illustrate our construction.

  11. Development of a core confidence-higher order construct.

    Science.gov (United States)

    Stajkovic, Alexander D

    2006-11-01

    The author develops core confidence as a higher order construct and suggests that a core confidence-higher order construct--not addressed by extant work motivation theories--is helpful in better understanding employee motivation in today's rapidly changing organizations. Drawing from psychology (social, clinical, and developmental) and social anthropology, the author develops propositions regarding the relationships between core confidence and performance, attitudes, and subjective well-being. The core confidence-higher order construct is proposed to be manifested by hope, self-efficacy, optimism, and resilience. The author reasons that these four variables share a common confidence core (a higher order construct) and may be considered as its manifestations. Suggestions for future research and implications of the work are discussed.

  12. On Doubly Degenerate Quasilinear Parabolic Equations of Higher Order

    Institute of Scientific and Technical Information of China (English)

    Zhen Hai LIU

    2005-01-01

    We deal with the existence of periodic solutions for doubly degenerate quasilinear parabolic equations of higher order, which can degenerate, on a part of the boundary, on a segment in the interior of the domain and in time.

  13. Feynman rules of higher-order poles in CHY construction

    Science.gov (United States)

    Huang, Rijun; Feng, Bo; Luo, Ming-xing; Zhu, Chuan-Jie

    2016-06-01

    In this paper, we generalize the integration rules for scattering equations to situations where higher-order poles are present. We describe the strategy to deduce the Feynman rules of higher-order poles from known analytic results of simple CHY-integrands, and propose the Feynman rules for single double pole and triple pole as well as duplex-double pole and triplex-double pole structures. We demonstrate the validation and strength of these rules by ample non-trivial examples.

  14. Higher-Order Quantum-Inspired Genetic Algorithms

    OpenAIRE

    Nowotniak, Robert; Kucharski, Jacek

    2014-01-01

    This paper presents a theory and an empirical evaluation of Higher-Order Quantum-Inspired Genetic Algorithms. Fundamental notions of the theory have been introduced, and a novel Order-2 Quantum-Inspired Genetic Algorithm (QIGA2) has been presented. Contrary to all QIGA algorithms which represent quantum genes as independent qubits, in higher-order QIGAs quantum registers are used to represent genes strings which allows modelling of genes relations using quantum phenomena. Performance comparis...

  15. Higher order aberrations of the eye: Part one

    Directory of Open Access Journals (Sweden)

    Marsha Oberholzer

    2016-03-01

    Full Text Available This article is the first in a series of two articles that provide a comprehensive literature review of higher order aberrations (HOAs of the eye. The present article mainly explains the general principles of such HOAs as well as HOAs of importance, and the measuring apparatus used to measure HOAs of the eye. The second article in the series discusses factors contributing to variable results in measurements of HOAs of the eye.Keywords: Higher order aberrations; wavefront aberrations; aberrometer

  16. Linear matrix differential equations of higher-order and applications

    Directory of Open Access Journals (Sweden)

    Mustapha Rachidi

    2008-07-01

    Full Text Available In this article, we study linear differential equations of higher-order whose coefficients are square matrices. The combinatorial method for computing the matrix powers and exponential is adopted. New formulas representing auxiliary results are obtained. This allows us to prove properties of a large class of linear matrix differential equations of higher-order, in particular results of Apostol and Kolodner are recovered. Also illustrative examples and applications are presented.

  17. Slice Energy in Higher Order Gravity Theories and Conformal Transformations

    CERN Document Server

    Cotsakis, S

    2004-01-01

    We show that there is a generic transport of energy between the scalar field generated by the conformal transformation of higher order gravity theories and the matter component. We give precise relations of this exchange and show that, unless we are in a stationary spacetime, slice energy is not generically conserved. These results translate into statements about the relative behaviour of ordinary matter, dark matter and dark energy in the context of higher order gravity.

  18. All-fiber Raman Probe using Higher Order Modes

    DEFF Research Database (Denmark)

    Larsen, Stine Højer Møller; Rishøj, Lars Søgaard; Rottwitt, Karsten

    2013-01-01

    We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes.......We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes....

  19. Dual equivalence in models with higher-order derivatives

    CERN Document Server

    Bazeia, D; Nascimento, J R S; Ribeiro, R F; Wotzasek, C

    2003-01-01

    We introduce a class of higher-order derivative models in (2,1) space-time dimensions. The models are described by a vector field, and contain a Proca-like mass term which prevents gauge invariance. We use the gauge embedding procedure to generate another class of higher-order derivative models, gauge-invariant and dual to the former class. We also show that the gauge embedding approach works appropriately when the vector field couples with fermionic matter.

  20. Higher order acoustoelastic Lamb wave propagation in stressed plates.

    Science.gov (United States)

    Pei, Ning; Bond, Leonard J

    2016-11-01

    Modeling and experiments are used to investigate Lamb wave propagation in the direction perpendicular to an applied stress. Sensitivity, in terms of changes in velocity, for both symmetrical and anti-symmetrical modes was determined. Codes were developed based on analytical expressions for waves in loaded plates and they were used to give wave dispersion curves. The experimental system used a pair of compression wave transducers on variable angle wedges, with set separation, and variable frequency tone burst excitation, on an aluminum plate 0.16 cm thick with uniaxial applied loads. The loads, which were up to 600 με, were measured using strain gages. Model results and experimental data are in good agreement. It was found that the change in Lamb wave velocity, due to the acoustoelastic effect, for the S1 mode exhibits about ten times more sensitive, in terms of velocity change, than the traditional bulk wave measurements, and those performed using the fundamental Lamb modes. The data presented demonstrate the potential for the use of higher order Lamb modes for online industrial stress measurement in plate, and that the higher sensitivity seen offers potential for improved measurement systems.

  1. Certifiable higher order sliding mode control: Practical stability margins approach

    Science.gov (United States)

    Panathula, Chandrasekhara Bharath

    The Higher Order Sliding Mode (HOSM) controllers are well known for their robustness/insensitivity to bounded perturbations and for handling any given arbitrary relative degree system. The HOSM controller is to be certified for robustness to unmodeled dynamics, before deploying the controller for practical applications. Phase Margin (PM) and Gain Margin ( GM) are the classical characteristics used in linear systems to quantify the linear controller robustness to unmodeled dynamics, and certain values of these margins are required to certify the controller. These conventional margins (PM and GM) are extended to Practical Stability Phase Margin (PSPM) and Practical Stability Gain Margin (PSGM) in this dissertation, and are used to quantify the HOSM control robustness to unmodeled dynamics, presiding the tool to close the gap for HOSM control certification. The proposed robustness metrics ( PSPM and PSGM) are identified by developing tools/algorithms based on Describing Function-Harmonic Balance method. In order for the HOSM controller to achieve the prescribed values on robustness metrics ( PSPM and PSGM), the HOSM controller is cascaded with a linear compensator. A case study of the application of the proposed metrics (PSPM and PSGM) for the certification of F-16 aircraft HOSM attitude control robustness to cascade unmodeled dynamics is presented. In addition, several simulation examples are presented to verify and to validate the proposed methodology.

  2. Chaos synchronization of coronary artery system based on higher order sliding mo de adaptive control%冠状动脉系统高阶滑模自适应混沌同步设计∗

    Institute of Scientific and Technical Information of China (English)

    赵占山; 张静; 丁刚; 张大坤

    2015-01-01

    Many biomedical engineering fields are studied by combining with nonlinear science which has major advances in theoretical curing related diseases. The coronary artery system is chosen as a muscular blood vessel model. With the change of vessel diameter, some chaotic behaviors will occur which may cause complex diseases such as myocardial infarction. In order to avoid the undesired chaotic motion, this paper investigates the finite-time chaos synchronization problem for a coronary artery system by utilizting high-order sliding mode adaptive control method. First, the error chaos synchronization system is obtained using the master and slave systems. Second, the error chaos synchronization system can be transformed into an integrator chain system by coordinate transformation, which is equivalent to an error chaos synchronization system. Considering that the sliding mode control has main obstacle (the control high activity and chattering phenomenon), a high-order sliding mode adaptive controller is designed for a coronary artery system with unknown disturbances at geometric homogeneity and integral sliding mode surface. The proposed method shows that the drive and response systems are synchronized and the states of the response system track the states of the drive system in finite-time. This approach does not require any information about the bound of disturbances in advance. Theoretic analysis based on Lyapunov theory proves that the systems with the proposed controller could be stabilized in finite-time. The convergence time of the system states is estimated. In order to alleviate the chattering effect, we use tanh(·) function in place of sign(·) function to design an improved high-order sliding mode adaptive controller. Simulation results show that the proposed adaptive sliding mode controller can achieve better robustness and adaptation against disturbances, which offer the theoretic basis for curing myocardial infarction.

  3. Higher Order Modes Excitation of Micro Cantilever Beams

    KAUST Repository

    Jaber, Nizar

    2014-05-01

    In this study, we present analytical and experimental investigation of electrically actuated micro cantilever based resonators. These devices are fabricated using polyimide and coated with chrome and gold layers from both sides. The cantilevers are highly curled up due to stress gradient, which is a common imperfection in surface micro machining. Using a laser Doppler vibrometer, we applied a noise signal to experimentally find the first four resonance frequencies. Then, using a data acquisition card, we swept the excitation frequency around the first four natural modes of vibrations. Theoretically, we derived a reduced order model using the Galerkin method to simulate the dynamics of the system. Extensive numerical analysis and computations were performed. The numerical analysis was able to provide good matching with experimental values of the resonance frequencies. Also, we proved the ability to excite higher order modes using partial electrodes with shapes that resemble the shape of the mode of interest. Such micro-resonators are shown to be promising for applications in mass and gas sensing.

  4. Near integrability of kink lattice with higher order interactions

    CERN Document Server

    Jiang, Yunguo; He, Song

    2016-01-01

    In the paper, we make use of Manton's analytical method to investigate the force between kink and the anti-kink with large distance in $1+1$ dimensional field theory. The related potential has infinite order corrections of exponential pattern, and coefficients for each order are determined. These coefficients can also be obtained by solving the equation of the fluctuation around the vacuum. At the lowest order, the kink lattice represents the Toda lattice. With higher order correction terms, the kink lattice can represent one kind of the generic Toda lattice. With only two sites, the kink lattice is classically integrable. If the number of sites of the lattice is larger than two, the kink lattice is not integrable but a near integrable system. We take use of the Flaschka's variables to study the Lax pair of the kink lattice. These Flaschka's variables have interesting algebraic relations and the non-integrability can be manifested. We also discussed the higher Hamiltonians for the deformed open Toda lattice, ...

  5. Higher-Order Factors of Personality: Do They Exist?

    Science.gov (United States)

    Ashton, Michael C.; Lee, Kibeom; Goldberg, Lewis R.; de Vries, Reinout E.

    2010-01-01

    Scales that measure the Big Five personality factors are often substantially intercorrelated. These correlations are sometimes interpreted as implying the existence of two higher-order factors of personality. We show that correlations between measures of broad personality factors do not necessarily imply the existence of higher-order factors, and might instead be due to variables that represent same-signed blends of orthogonal factors. Therefore, the hypotheses of higher-order factors and blended variables can only be tested with data on lower-level personality variables that define the personality factors. We compared the higher-order factor model and the blended variable model in three participant samples using the Big Five Aspect Scales, and found better fit for the latter model. In other analyses using the HEXACO Personality Inventory, we identified mutually uncorrelated markers of six personality factors. We conclude that correlations between personality factor scales can be explained without postulating any higher-order dimensions of personality. PMID:19458345

  6. Emotion recognition from EEG using higher order crossings.

    Science.gov (United States)

    Petrantonakis, Panagiotis C; Hadjileontiadis, Leontios J

    2010-03-01

    Electroencephalogram (EEG)-based emotion recognition is a relatively new field in the affective computing area with challenging issues regarding the induction of the emotional states and the extraction of the features in order to achieve optimum classification performance. In this paper, a novel emotion evocation and EEG-based feature extraction technique is presented. In particular, the mirror neuron system concept was adapted to efficiently foster emotion induction by the process of imitation. In addition, higher order crossings (HOC) analysis was employed for the feature extraction scheme and a robust classification method, namely HOC-emotion classifier (HOC-EC), was implemented testing four different classifiers [quadratic discriminant analysis (QDA), k-nearest neighbor, Mahalanobis distance, and support vector machines (SVMs)], in order to accomplish efficient emotion recognition. Through a series of facial expression image projection, EEG data have been collected by 16 healthy subjects using only 3 EEG channels, namely Fp1, Fp2, and a bipolar channel of F3 and F4 positions according to 10-20 system. Two scenarios were examined using EEG data from a single-channel and from combined-channels, respectively. Compared with other feature extraction methods, HOC-EC appears to outperform them, achieving a 62.3% (using QDA) and 83.33% (using SVM) classification accuracy for the single-channel and combined-channel cases, respectively, differentiating among the six basic emotions, i.e., happiness, surprise, anger, fear, disgust, and sadness. As the emotion class-set reduces its dimension, the HOC-EC converges toward maximum classification rate (100% for five or less emotions), justifying the efficiency of the proposed approach. This could facilitate the integration of HOC-EC in human machine interfaces, such as pervasive healthcare systems, enhancing their affective character and providing information about the user's emotional status (e.g., identifying user's emotion

  7. Automatic Parallelization and Optimization of Programs by Proof Rewriting

    NARCIS (Netherlands)

    Hurlin, C.; Palsberg, J.; Su, Z.

    2009-01-01

    We show how, given a program and its separation logic proof, one can parallelize and optimize this program and transform its proof simultaneously to obtain a proven parallelized and optimized program. To achieve this goal, we present new proof rules for generating proof trees and a rewrite system on

  8. Weak Convergence and Uniform Normalization in Infinitary Rewriting

    DEFF Research Database (Denmark)

    Simonsen, Jakob Grue

    2010-01-01

    We study infinitary term rewriting systems containing finitely many rules. For these, we show that if a weakly convergent reduction is not strongly convergent, it contains a term that reduces to itself in one step (but the step itself need not be part of the reduction). Using this result, we prov...

  9. Weak convergence and uniform normalization in infinitary rewriting

    DEFF Research Database (Denmark)

    Simonsen, Jakob Grue

    2010-01-01

    We study infinitary term rewriting systems containing finitely many rules. For these, we show that if a weakly convergent reduction is not strongly convergent, it contains a term that reduces to itself in one step (but the step itself need not be part of the reduction). Using this result, we prov...

  10. Stochastic Models for Phylogenetic Trees on Higher-order Taxa

    CERN Document Server

    Aldous, David; Popovic, Lea

    2007-01-01

    Simple stochastic models for phylogenetic trees on species have been well studied. But much paleontology data concerns time series or trees on higher-order taxa, and any broad picture of relationships between extant groups requires use of higher-order taxa. A coherent model for trees on (say) genera should involve both a species-level model and a model for the classification scheme by which species are assigned to genera. We present a general framework for such models, and describe three alternate classification schemes. Combining with the species-level model of Aldous-Popovic (2005), one gets models for higher-order trees, and we initiate analytic study of such models. In particular we derive formulas for the lifetime of genera, for the distribution of number of species per genus, and for the offspring structure of the tree on genera.

  11. Higher-order theories from the minimal length

    Science.gov (United States)

    Dias, M.; Hoff da Silva, J. M.; Scatena, E.

    2016-06-01

    We show that the introduction of a minimal length in the context of noncommutative space-time gives rise (after some considerations) to higher-order theories. We then explicitly demonstrate how these higher-derivative theories appear as a generalization of the standard electromagnetism and general relativity by applying a consistent procedure that modifies the original Maxwell and Einstein-Hilbert actions. In order to set a bound on the minimal length, we compare the deviations from the inverse-square law with the potentials obtained in the higher-order theories and discuss the validity of the results. The introduction of a quantum bound for the minimal length parameter β in the higher-order QED allows us to lower the actual limits on the parameters of higher-derivative gravity by almost half of their order of magnitude.

  12. Higher-order theories from the minimal length

    CERN Document Server

    Dias, Marco; Scatena, Eslley

    2016-01-01

    We show that the introduction of a minimal length in the context of non-commutative spacetime gives rise (after some considerations) to higher-order theories. We then explicitly demonstrate how these higher-derivative theories appear as a generalization of the standard electromagnetism and general relativity by applying a consistent procedure that modifies the original Maxwell and Einstein-Hilbert actions. In order to set a bound on the minimal length, we compare the deviations from the inverse-square law with the potentials obtained in the higher-order theories and discuss the validity of the results. The introduction of a quantum bound for the minimal length parameter $\\sqrt{\\beta}$ in the higher-order QED allows us to lower the actual limits on the parameters of higher-derivative gravity by almost half of their order of magnitude.

  13. Higher-order Kerr effect and harmonic cascading in gases

    CERN Document Server

    Bache, Morten; Minardi, Stefano

    2012-01-01

    The higher-order Kerr effect (HOKE) has been recently advocated to explain measurements of the saturation of the nonlinear refractive index in gases. Here we show that cascaded third-harmonic generation results in an effective fifth order nonlinearity that is negative and significant. Higher-order harmonic cascading will also occur from the HOKE, and the cascading contributions may significantly modify the observed nonlinear index change. At lower wavelengths cascading increases the HOKE saturation intensity, while for longer wavelengths cascading will decrease the HOKE saturation intensity.

  14. Detection of small target using recursive higher order statistics

    Science.gov (United States)

    Hou, Wang; Sun, Hongyuan; Lei, Zhihui

    2014-02-01

    In this paper, a recursive higher order statistics algorithm is proposed for small target detection in temporal domain. Firstly, the background of image sequence is normalized. Then, the higher order statistics are recursively solved in image sequence to obtain the feature image. Finally, the feature image is segmented with threshold to detect the small target. To validate the algorithm proposed in this paper, five simulated and one semi-simulation image sequences are created. The ROC curves are employed for evaluation of experimental results. Experiment results show that our method is very effective for small target detection.

  15. Summation of Higher Order Effects using the Renormalization Group Equation

    CERN Document Server

    Elias, V; Sherry, T N

    2004-01-01

    The renormalization group (RG) is known to provide information about radiative corrections beyond the order in perturbation theory to which one has calculated explicitly. We first demonstrate the effect of the renormalization scheme used on these higher order effects determined by the RG. Particular attention is payed to the relationship between bare and renormalized quantities. Application of the method of characteristics to the RG equation to determine higher order effects is discussed, and is used to examine the free energy in thermal field theory, the relationship between the bare and renormalized coupling and the effective potential in massless scalar electrodynamics.

  16. Higher-order Laplace equations and hyper-Cauchy distributions

    CERN Document Server

    Orsingher, Enzo

    2012-01-01

    In this paper we introduce new distributions which are solutions of higher-order Laplace equations. It is proved that their densities can be obtained by folding and symmetrizing Cauchy distributions. Another class of probability laws related to higher-order Laplace equations is obtained by composing pseudo-processes with positively-skewed Cauchy distributions which produce asymmetric Cauchy densities in the odd-order case. A special attention is devoted to the third-order Laplace equation where the connection between the Cauchy distribution and the Airy functions is obtained and analyzed.

  17. Interference of selective higher-order modes in optical fibers

    Institute of Scientific and Technical Information of China (English)

    Li Enbang; Peng Gangding

    2007-01-01

    The interference of selective higher-order modes in optical fibers is investigated both theoretically and experimentally.It has been demonstrated that by coupling the LP01 mode in a step-index single-mode fiber(SMF)to the LPom modes in step-index muhimode fibers(MMFs)with different parameters,one can selectively generate higher-order modes and construct all-fiber interferometers.The research presented in this paper forms a basis of a new type of fiber devices with potential applications in fiber sensing,optical fiber communications,and optical signal processing.

  18. Higher order nonlinearity and synchronization of quantum cascade lasers

    Institute of Scientific and Technical Information of China (English)

    Taraprasad Chattopadhyay; Prosenjit Bhattacharyya

    2011-01-01

    This paper presents a closed-form analysis of the synchronization phenomenon of the quantum cascade laser (QCL). The analysis has been made with considering higher order nonlinearity of the modal gain of the QCL. The frequency response characteristics of the synchronized QCL along with the stability of the locked state, the effect of nonlinearity on the lockband of the QCL and the amplitude limiting action of the locked QCL have been calculated. The analysis demonstrates the effect of higher order nonlinearity on the properties of the synchronized QCL.

  19. The Cauchy problem for higher order abstract differential equations

    CERN Document Server

    Xiao, Ti-Jun

    1998-01-01

    This monograph is the first systematic exposition of the theory of the Cauchy problem for higher order abstract linear differential equations, which covers all the main aspects of the developed theory. The main results are complete with detailed proofs and established recently, containing the corresponding theorems for first and incomplete second order cases and therefore for operator semigroups and cosine functions. They will find applications in many fields. The special power of treating the higher order problems directly is demonstrated, as well as that of the vector-valued Laplace transforms in dealing with operator differential equations and operator families. The reader is expected to have a knowledge of complex and functional analysis.

  20. Higher-order spectra for identification of nonlinear modal coupling

    Science.gov (United States)

    Hickey, Daryl; Worden, Keith; Platten, Michael F.; Wright, Jan R.; Cooper, Jonathan E.

    2009-05-01

    Over the past four decades considerable work has been done in the area of power spectrum estimation. The information contained within the power spectrum relates to a signal's autocorrelation or 'second-order statistics'. The power spectrum provides a complete statistical description of a Gaussian process; however, a problem with this information is that it is phase blind. This problem is addressed if one turns to a system's frequency response function (FRF). The FRF graphs the magnitude and phase of the frequency response of a system; in order to do this it requires information regarding the frequency content of the input and output signals. Situations arise in science and engineering whereby signal analysts are required to look beyond second-order statistics and analyse a signal's higher-order statistics (HOS). HOS or spectra give information on a signal's deviation from Gaussianity and consequently are a good indicator function for the presence of nonlinearity within a system. One of the main problems in nonlinear system identification is that of high modal density. Many modelling schemes involve making some expansion of the nonlinear restoring force in terms of polynomial or other basis terms. If more than one degree-of-freedom is involved this becomes a multivariate problem and the number of candidate terms in the expansion grows explosively with the order of nonlinearity and the number of degrees-of-freedom. This paper attempts to use HOS to detect and qualify nonlinear behaviour for a number of symmetrical and asymmetrical systems over a range of degrees-of-freedom. In doing so the paper also attempts to show that HOS are a more sensitive tool than the FRF in detecting nonlinearity. Furthermore, the object of this paper is to try and identify which modes couple in a nonlinear manner in order to reduce the number of candidate coupling terms, for a model, as much as possible. The bispectrum method has previously been applied to simple low-DOF systems with high

  1. Solving Nonstiff Higher Order Odes Using Variable Order Step Size Backward Difference Directly

    Directory of Open Access Journals (Sweden)

    Ahmad Fadly Nurullah Rasedee

    2014-01-01

    Full Text Available The current numerical techniques for solving a system of higher order ordinary differential equations (ODEs directly calculate the integration coefficients at every step. Here, we propose a method to solve higher order ODEs directly by calculating the integration coefficients only once at the beginning of the integration and if required once more at the end. The formulae will be derived in terms of backward difference in a constant step size formulation. The method developed will be validated by solving some higher order ODEs directly using variable order step size. To simplify the evaluations of the integration coefficients, we find the relationship between various orders. The results presented confirmed our hypothesis.

  2. Higher order variability properties of accreting black holes

    Science.gov (United States)

    Maccarone, Thomas J.; Coppi, Paolo S.

    2002-11-01

    To better constrain the emission mechanism underlying the hard state of galactic black hole candidates, we use high-time resolution RXTE light curves for Cyg X-1 and GX 339-4 to compute two higher order variability statistics for these objects, the skewness and the Fourier bispectrum. Similar analyses, in particular using the skewness measure, have been attempted previously, but the photon collection area of RXTE allows us to present results of much greater statistical significance. The results for the two objects are qualitatively similar, reinforcing the idea that the same basic mechanisms are at work in both. We find a significantly positive skewness for variability time-scales less than ~1 s, and a negative skewness for time-scales from 1 to 5 s. Such a skewness pattern cannot be reproduced by the simplest shot variability models where individual shots have a fixed profile and intensity and are uncorrelated in time. Further evidence against simple-shot models comes from the significant detection of a non-zero bicoherence for Fourier periods ~0.1-10 s, implying that significant coupling does exist between variations on these time-scales. We discuss how current popular models for variability in black hole systems can be modified to match these observations. Using simulated light curves, we suggest that the most likely way to reproduce this observed behaviour is to have the variability come in groups of many shots, with the number of shots per unit time fitting an envelope function that has a rapid rise and a slow decay, while the individual shots have a slow rise and a rapid decay. Invoking a finite-energy reservoir that is depleted by each shot is a natural way of producing the required shot correlations.

  3. Differences in response to serotonergic activation between first and higher order thalamic nuclei.

    Science.gov (United States)

    Varela, C; Sherman, S Murray

    2009-08-01

    Two types of thalamic nuclei have been recognized: first order, which relay information from subcortical sources, and higher order, which may relay information from one cortical area to another. We have recently shown that muscarinic agonists depolarize all first order and most higher order relay cells but hyperpolarize a significant proportion of higher order relay cells. We now extend this result to serotonergic agonists, using rat thalamic brain slices and whole-cell, current- and voltage-clamp recordings from relay cells in various first order (the lateral geniculate nucleus, the ventral posterior nucleus, and the ventral portion of the medial geniculate body) and higher order nuclei (the lateral posterior, the posterior medial nucleus, and the dorsal portion of the medial geniculate body). Similar to the effects of muscarinic agonists, we found that first and most higher order relay cells were depolarized by serotonergic agonists, but 15% of higher order relay cells responded with hyperpolarization. Thus different subsets of higher order relay cells are hyperpolarized by these modulatory systems, which could have implications for the transfer of information between cortical areas.

  4. Extracting the jet azimuthal anisotropy from higher order cumulants

    CERN Document Server

    Lokhtin, Igor P; Snigirev, A M

    2003-01-01

    We analyze the method for calculation of a coefficient of jet azimuthal anisotropy without reconstruction of the nuclear reaction plane considering the higher order correlators between the azimuthal position of jet axis and the angles of particles not incorporated in the jet. The reliability of this technique in the real physical situation under LHC conditions is illustrated.

  5. Decidable Fragments of a Higher Order Calculus with Locations

    DEFF Research Database (Denmark)

    Hüttel, Hans; Godskesen, Jens Christian; Haagensen, Bjørn

    2009-01-01

    Homer is a higher order process calculus with locations. In this paper we study Homer in the setting of the semantic finite control property, which is a finite reachability criterion that implies decidability of barbed bisimilarity. We show that strong and weak barbed bisimilarity are undecidable...... control π-calculus in Homer....

  6. Higher Order Risk Attitudes, Demographics, and Financial Decisions

    NARCIS (Netherlands)

    Noussair, C.N.; Trautmann, S.T.; van de Kuilen, G.

    2011-01-01

    We conduct an experiment to study the prevalence of the higher order risk attitudes of prudence and temperance, in a large demographically representative sample, as well as in a sample of undergraduate students. Participants make pairwise choices between lotteries of the form proposed by Eeckhoudt a

  7. Higher-Order Hierarchical Legendre Basis Functions in Applications

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter;

    2007-01-01

    degree of orthogonality. The basis functions are well-suited for solution of complex electromagnetic problems involving multiple homogeneous or inhomogeneous dielectric regions, metallic surfaces, layered media, etc. This paper presents real-life complex antenna radiation problems modeled...... with electromagnetic simulation tools based on the higher-order hierarchical Legendre basis functions....

  8. Enhancing Higher Order Thinking Skills through Clinical Simulation

    Science.gov (United States)

    Varutharaju, Elengovan; Ratnavadivel, Nagendralingan

    2014-01-01

    Purpose: The study aimed to explore, describe and analyse the design and implementation of clinical simulation as a pedagogical tool in bridging the deficiency of higher order thinking skills among para-medical students, and to make recommendations on incorporating clinical simulation as a pedagogical tool to enhance thinking skills and align the…

  9. Heat polynomial analogs for higher order evolution equations

    Directory of Open Access Journals (Sweden)

    G. N. Hile

    2001-05-01

    Full Text Available Polynomial solutions analogous to the heat polynomials are demonstrated for higher order linear homogeneous evolution equations with coefficients depending on the time variable. Further parallels with the heat polynomials are established when the equation is parabolic with constant coefficients and only highest order terms.

  10. Multilevel Fast Multipole Method for Higher Order Discretizations

    DEFF Research Database (Denmark)

    Borries, Oscar Peter; Meincke, Peter; Jorgensen, Erik;

    2014-01-01

    The multi-level fast multipole method (MLFMM) for a higher order (HO) discretization is demonstrated on high-frequency (HF) problems, illustrating for the first time how an efficient MLFMM for HO can be achieved even for very large groups. Applying several novel ideas, beneficial to both lower or...

  11. Higher Order Language Competence and Adolescent Mental Health

    Science.gov (United States)

    Cohen, Nancy J.; Farnia, Fataneh; Im-Bolter, Nancie

    2013-01-01

    Background: Clinic and community-based epidemiological studies have shown an association between child psychopathology and language impairment. The demands on language for social and academic adjustment shift dramatically during adolescence and the ability to understand the nonliteral meaning in language represented by higher order language…

  12. Meta-Logical Reasoning in Higher-Order Logic

    DEFF Research Database (Denmark)

    Villadsen, Jørgen; Schlichtkrull, Anders; Hess, Andreas Viktor

    The semantics of first-order logic (FOL) can be described in the meta-language of higher-order logic (HOL). Using HOL one can prove key properties of FOL such as soundness and completeness. Furthermore, one can prove sentences in FOL valid using the formalized FOL semantics. To aid in the constru...

  13. RECURSIVE CLASSIFICATION OF MQAM SIGNALS BASED ON HIGHER ORDER CUMULANTS

    Institute of Scientific and Technical Information of China (English)

    Chen Weidong; Yang Shaoquan

    2002-01-01

    A new feature based on higher order cumulants is proposed for classification of MQAM signals. Theoretical analysis justify that the new feature is invariant with respect to translation (shift), scale and rotation transform of signal constellations, and can suppress color or white additive Gaussian noise. Computer simulation shows that the proposed recursive orderreduction based classification algorithm can classify MQAM signals with any order.

  14. Higher order Fano graphene metamaterials for nanoscale optical sensing.

    Science.gov (United States)

    Guo, Xiangdong; Hu, Hai; Zhu, Xing; Yang, Xiaoxia; Dai, Qing

    2017-09-28

    Plasmonic Fano metamaterials provide a unique platform for optical sensing applications due to their sharp spectral response and the ability to confine light to nanoscale regions that make them a strong prospect for refractive-index sensing. Higher order Fano resonance modes in noble metal plasmonic structures can further improve the sensitivity, but their applications are heavily limited by crosstalk between different modes due to the large damping rates and broadband spectral responses of the metal plasmon modes. Here, we create pure higher order Fano modes by designing asymmetric metamaterials comprised of a split-ring resonator and disk with a low-loss graphene plasmon. These higher order modes are highly sensitive to the nanoscale analyte (8 nm thick) both in refractive-index and in infrared vibrational fingerprint sensing, as demonstrated by the numerical calculation. The frequency sensitivity and figure-of-merit of the hexacontatetrapolar mode can reach 289 cm(-1) per RIU and 29, respectively, and it can probe the weak infrared vibrational modes of the analyte with more than 400 times enhancement. The enhanced sensitivity and tunability of higher order Fano graphene metamaterials promise a high-performance nanoscale optical sensor.

  15. The Role of Formative Feedback in Promoting Higher Order ...

    African Journals Online (AJOL)

    DrNneka

    can promote higher order thinking skills in the classroom. The proposed theoretical ... known predictable, well-known approach or pathway explicitly suggested by the task, ... problems, and enhancing open-ended group work and class discussions, there is a high ..... Journal of Research in Mathematics Education, 28(5),.

  16. Higher-Order Item Response Models for Hierarchical Latent Traits

    Science.gov (United States)

    Huang, Hung-Yu; Wang, Wen-Chung; Chen, Po-Hsi; Su, Chi-Ming

    2013-01-01

    Many latent traits in the human sciences have a hierarchical structure. This study aimed to develop a new class of higher order item response theory models for hierarchical latent traits that are flexible in accommodating both dichotomous and polytomous items, to estimate both item and person parameters jointly, to allow users to specify…

  17. Higher-order structure of rRNA

    Science.gov (United States)

    Gutell, R. R.; Woese, C. R.

    1986-01-01

    A comparative search for phylogenetically covarying basepair replacements within potential helices has been the only reliable method to determine the correct secondary structure of the 3 rRNAs, 5S, 16S, and 23S. The analysis of 16S from a wide phylogenetic spectrum, that includes various branches of the eubacteria, archaebacteria, eucaryotes, in addition to the mitochondria and chloroplast, is beginning to reveal the constraints on the secondary structures of these rRNAs. Based on the success of this analysis, and the assumption that higher order structure will also be phylogenetically conserved, a comparative search was initiated for positions that show co-variation not involved in secondary structure helices. From a list of potential higher order interactions within 16S rRNA, two higher-order interactions are presented. The first of these interactions involves positions 570 and 866. Based on the extent of phylogenetic covariation between these positions while maintaining Watson-Crick pairing, this higher-order interaction is considered proven. The other interaction involves a minimum of six positions between the 1400 and 1500 regions of the 16S rRNA. Although these patterns of covariation are not as striking as the 570/866 interaction, the fact that they all exist in an anti-parallel fashion and that experimental methods previously implicated these two regions of the molecule in tRNA function suggests that these interactions be given serious consideration.

  18. Generating superpositions of higher order bessel beams [Conference paper

    CSIR Research Space (South Africa)

    Vasilyeu, R

    2009-10-01

    Full Text Available of Higher Order Bessel Beams R. Vasilyeu1, A. Dudley2,3, N. Khilo1, and A. Forbes2,3 1 B.I. Stepanov Institute of Physics of NAS of Belarus, Nezalezhnasti Ave., 68, 220072 Minsk, Belarus r.vasilyev@dragon.bas-net.by and n.khilo@dragon.bas-net.by 2...

  19. Building Higher-Order Markov Chain Models with EXCEL

    Science.gov (United States)

    Ching, Wai-Ki; Fung, Eric S.; Ng, Michael K.

    2004-01-01

    Categorical data sequences occur in many applications such as forecasting, data mining and bioinformatics. In this note, we present higher-order Markov chain models for modelling categorical data sequences with an efficient algorithm for solving the model parameters. The algorithm can be implemented easily in a Microsoft EXCEL worksheet. We give a…

  20. Higher-Order Coloured Unification and Natural Language Semantics

    CERN Document Server

    Gardent, C; Gardent, Claire; Kohlhase, Michael

    1996-01-01

    In this paper, we show that Higher-Order Coloured Unification - a form of unification developed for automated theorem proving - provides a general theory for modeling the interface between the interpretation process and other sources of linguistic, non semantic information. In particular, it provides the general theory for the Primary Occurrence Restriction which (Dalrymple, Shieber and Pereira, 1991)'s analysis called for.

  1. First Measurements of Higher Order Optics Parameters in the LHC

    CERN Document Server

    Vanbavinckhove, G; Bartolini, R; Calaga, R; Giovannozzi, M; Maclean, E H; Miyamoto, R; Schmidt, F; Tomas, R

    2011-01-01

    Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these pa- rameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed sim- ulations are compared to the measurements together with discussions on the measurement limitations.

  2. Higher-order momentum distributions and locally affine LDDMM registration

    DEFF Research Database (Denmark)

    Sommer, Stefan Horst; Nielsen, Mads; Darkner, Sune;

    2013-01-01

    higher-order momentum distributions in the large deformation diffeomorphic metric mapping (LDDMM) registration framework. While the zeroth-order moments previously used in LDDMM only describe local displacement, the first-order momenta that are proposed here represent a basis that allows local...

  3. Abstract Operators and Higher-order Linear Partial Differential Equation

    Institute of Scientific and Technical Information of China (English)

    BI Guang-qing; BI Yue-kai

    2011-01-01

    We summarize several relevant principles for the application of abstract operators in partial differential equations,and combine abstract operators with the Laplace transform.Thus we have developed the theory of partial differential equations of abstract operators and obtained the explicit solutions of initial value problems for a class of higher-order linear partial differential equations.

  4. Numerical modeling of higher order magnetic moments in UXO discrimination

    Science.gov (United States)

    Sanchez, V.; Yaoguo, L.; Nabighian, M.N.; Wright, D.L.

    2008-01-01

    The surface magnetic anomaly observed in unexploded ordnance (UXO) clearance is mainly dipolar, and consequently, the dipole is the only magnetic moment regularly recovered in UXO discrimination. The dipole moment contains information about the intensity of magnetization but lacks information about the shape of the target. In contrast, higher order moments, such as quadrupole and octupole, encode asymmetry properties of the magnetization distribution within the buried targets. In order to improve our understanding of magnetization distribution within UXO and non-UXO objects and to show its potential utility in UXO clearance, we present a numerical modeling study of UXO and related metallic objects. The tool for the modeling is a nonlinear integral equation describing magnetization within isolated compact objects of high susceptibility. A solution for magnetization distribution then allows us to compute the magnetic multipole moments of the object, analyze their relationships, and provide a depiction of the anomaly produced by different moments within the object. Our modeling results show the presence of significant higher order moments for more asymmetric objects, and the fields of these higher order moments are well above the noise level of magnetic gradient data. The contribution from higher order moments may provide a practical tool for improved UXO discrimination. ?? 2008 IEEE.

  5. Higher-Order Integral Equation Methods in Computational Electromagnetics

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Meincke, Peter

    Higher-order integral equation methods have been investigated. The study has focused on improving the accuracy and efficiency of the Method of Moments (MoM) applied to electromagnetic problems. A new set of hierarchical Legendre basis functions of arbitrary order is developed. The new basis...

  6. Improved Multilevel Fast Multipole Method for Higher-Order discretizations

    DEFF Research Database (Denmark)

    Borries, Oscar Peter; Meincke, Peter; Jorgensen, Erik

    2014-01-01

    The Multilevel Fast Multipole Method (MLFMM) allows for a reduced computational complexity when solving electromagnetic scattering problems. Combining this with the reduced number of unknowns provided by Higher-Order discretizations has proven to be a difficult task, with the general conclusion b...

  7. Higher order QCD corrections in small x physics

    Energy Technology Data Exchange (ETDEWEB)

    Chachamis, G.

    2006-11-15

    We study higher order QCD corrections in small x Physics. The numerical implementation of the full NLO photon impact factor is the remaining necessary piece for the testing of the NLO BFKL resummation against data from physical processes, such as {gamma}{sup *}{gamma}{sup *} collisions. We perform the numerical integration over phase space for the virtual corrections to the NLO photon impact factor. This, along with the previously calculated real corrections, makes feasible in the near future first estimates for the {gamma}*{gamma}* total cross section, since the convolution of the full impact factor with the NLO BFKL gluon Green's function is now straightforward. The NLO corrections for the photon impact factor are sizeable and negative. In the second part of this thesis, we estimate higher order correction to the BK equation. We are mainly interested in whether partonic saturation delays or not in rapidity when going beyond the leading order. In our investigation, we use the so called 'rapidity veto' which forbid two emissions to be very close in rapidity, to 'switch on' higher order corrections to the BK equation. From analytic and numerical analysis, we conclude that indeed saturation does delay in rapidity when higher order corrections are taken into account. In the last part, we investigate higher order QCD corrections as additional corrections to the Electroweak (EW) sector. The question of whether BFKL corrections are of any importance in the Regge limit for the EW sector seems natural; although they arise in higher loop level, the accumulation of logarithms in energy s at high energies, cannot be dismissed without an investigation. We focus on the process {gamma}{gamma}{yields}ZZ. We calculate the pQCD corrections in the forward region at leading logarithmic (LL) BFKL accuracy, which are of the order of few percent at the TeV energy scale. (orig.)

  8. Higher-order terms in sensitivity analysis through a differential approach

    Energy Technology Data Exchange (ETDEWEB)

    Dubi, A.; Dudziak, D.J.

    1981-06-01

    A differential approach to sensitivity analysis has been developed that eliminates some difficulties existing in previous work. The new development leads to simple explicit expressions for the first-order perturbation as well as any higher-order terms. The higher-order terms are dependent only on differentials of the transport operator, the unperturbed flux, the adjoint flux, and the unperturbed Green's function of the system.

  9. [The Pharaohs: slave merchants or organizers of an efficient welfare system? Re-writing history through new documentation and research].

    Science.gov (United States)

    Melino, C; Del Vecchio, R; Druda, L

    2003-01-01

    The Authors have studied documents dating from the era of the Pharaohs, that is to say: the papyruses of Ebers and Smith, and have come to the conclusion that the recent claims by some archaeologists that the Egyptian workmen who built the Pyramids, were protected by health regulations and not treated as slaves, is true. This is a new interpretation of Egyptian history, because up to now, it has always been thought that the workmen were slaves. The construction of the Pharaoh's tomb was a team work including members of the upper classes (architects, physicians) and the lower classes (masons, workmen) and was the demonstration of a contribution and a symbol of recognition from all members of the team to the head of the society (the Pharaoh), who was their employer and took their interests into consideration e.g. health regulations. The Authors have also deduced from other sources of information that a public health system and welfare organization, comparable to our present day Legislative Decree 626/94, did in fact exist in the ancient world.

  10. The Application of Rewriting in Cultural Transfer

    Institute of Scientific and Technical Information of China (English)

    赵敏洁

    2016-01-01

    In the context of globalization, cultural exchange is frequently conducted between countries in translating activities. Comparing with linguistic transfer, cultural transfer is frequented applied as to achieve communicative equivalence. Studies of rewriting applied as a method of cultural translation from Chinese to English are still relatively weak in the field of translation in China. Exclusive research on the methods for cultural translation is still uncompleted. In the last decade, when comes to cultural elements in translation, methods as restoring sounds, adding extra explanation, or detecting equivalent concepts have been most-ly discussed, but rewriting is rarely involved in it. This thesis reviews previous definitions for rewriting or adaptation;analyses the difference between linguistic transfer and cultural transfer, and why rewriting is adopted as an effective method for cultural translation;the application of rewriting will break up the dominance of occidental culture in the world while make oriental cul-ture become influential in the western world.

  11. A new approach for global controllability of higher order Boolean control network.

    Science.gov (United States)

    Chen, Hao; Sun, Jitao

    2013-03-01

    Using the semi-tensor product, the global control problem of the higher order Boolean control network with avoiding set is considered. First, the number of different control sequences that drive the higher order Boolean control network from the initial state to the destination state while avoiding undesirable set is provided. Then, the definition of global controllability of higher order Boolean control network is given. Third, by using the classical theory of nonnegative matrices, the necessary and sufficient condition for the global controllability of higher order Boolean control network with avoiding set is presented. Furthermore, a sufficient condition for k fixed-time global controllability of the system is also obtained. At last, an example is given to illustrate the main results.

  12. Higher Order Kernels and Locally Affine LDDMM Registration

    CERN Document Server

    Sommer, Stefan; Darkner, Sune; Pennec, Xavier

    2011-01-01

    To achieve sparse description that allows intuitive analysis, we aim to represent deformation with a basis containing interpretable elements, and we wish to use elements that have the description capacity to represent the deformation compactly. We accomplish this by introducing higher order kernels in the LDDMM registration framework. The kernels allow local description of affine transformations and subsequent compact description of non-translational movement and of the entire non-rigid deformation. This is obtained with a representation that contains directly interpretable information from both mathematical and modeling perspectives. We develop the mathematical construction behind the higher order kernels, we show the implications for sparse image registration and deformation description, and we provide examples of how the capacity of the kernels enables registration with a very low number of parameters. The capacity and interpretability of the kernels lead to natural modeling of articulated movement, and th...

  13. Higher order theories and their relationship with noncommutativity

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Santos, Oscar, E-mail: oscarsanbuzz@yahoo.com.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, C.P. 09340, México D.F., México (Mexico); Vergara, José David, E-mail: vergara@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, C.P. 04510, México D.F., México (Mexico)

    2014-06-13

    We present a relationship between noncommutativity and higher order time derivative theories using a perturbation method. We make a generalization of the Chern–Simons quantum mechanics for higher order time derivatives. This model presents noncommutativity in a natural way when we project to low-energy physical states without the necessity of taking the strong field limit. We quantize the theory using a Bopp's shift of the noncommutative variables and we obtain a spectrum without negative energies, under the perturbation limits. In addition, we extent the model to high order time derivatives and noncommutativity with variable dependent parameter. - Highlights: • We show a relationship between high order derivative theories and noncommutativity. • The noncommutativity appears when we project to low-energy physical states. • We extend the model to high order time derivatives. • We include cases with variable dependent noncommutative parameter.

  14. Higher order gravity theories and their black hole solutions

    CERN Document Server

    Charmousis, Christos

    2008-01-01

    We discuss a particular higher order gravity theory, Lovelock theory, that generalises in higher dimensions, general relativity. After briefly motivating modifications of gravity, we will introduce the theory in question and we will argue that it is a unique, mathematically sensible, and physically interesting extension of general relativity. We will see, by using the formalism of differential forms, the relation of Lovelock gravity to differential geometry and topology of even dimensional manifolds. We will then discuss a generic staticity theorem, which will give us the charged static black hole solutions. We will examine their asymptotic behavior, analyse their horizon structure and briefly their thermodynamics. We will then examine the distributional matching conditions for Lovelock theory. We will see how induced 4 dimensional Einstein-Hilbert terms result on the brane geometry from the higher order Lovelock terms. With the junction conditions at hand, we will go back to the black hole solutions and give...

  15. Comparison Criteria for Nonlinear Functional Dynamic Equations of Higher Order

    Directory of Open Access Journals (Sweden)

    Taher S. Hassan

    2016-01-01

    Full Text Available We will consider the higher order functional dynamic equations with mixed nonlinearities of the form xnt+∑j=0Npjtϕγjxφjt=0, on an above-unbounded time scale T, where n≥2, xi(t≔ri(tϕαixi-1Δ(t,  i=1,…,n-1,   with  x0=x,  ϕβ(u≔uβsgn⁡u, and α[i,j]≔αi⋯αj. The function φi:T→T is a rd-continuous function such that limt→∞φi(t=∞ for j=0,1,…,N. The results extend and improve some known results in the literature on higher order nonlinear dynamic equations.

  16. Statistics of predictions with missing higher order corrections

    CERN Document Server

    Berthier, Laure

    2016-01-01

    Effective operators have been used extensively to understand small deviations from the Standard Model in the search for new physics. So far there has been no general method to fit for small parameters when higher order corrections in these parameters are present but unknown. We present a new technique that solves this problem, allowing for an exact p-value calculation under the assumption that higher order theoretical contributions can be treated as gaussian distributed random variables. The method we propose is general, and may be used in the analysis of any perturbative theoretical prediction, ie.~truncated power series. We illustrate this new method by performing a fit of the Standard Model Effective Field Theory parameters, which include eg.~anomalous gauge and four-fermion couplings.

  17. Higher order moments of lensing convergence - I. Estimate from simulations

    CERN Document Server

    Vicinanza, M; Maoli, R; Scaramella, R; Er, X

    2016-01-01

    Large area lensing surveys are expected to make it possible to use cosmic shear tomography as a tool to severely constrain cosmological parameters. To this end, one typically relies on second order statistics such as the two - point correlation fucntion and its Fourier counterpart, the power spectrum. Moving a step forward, we wonder whether and to which extent higher order stastistics can improve the lensing Figure of Merit (FoM). In this first paper of a series, we investigate how second, third and fourth order lensing convergence moments can be measured and use as probe of the underlying cosmological model. We use simulated data and investigate the impact on moments estimate of the map reconstruction procedure, the cosmic variance, and the intrinsic ellipticity noise. We demonstrate that, under realistic assumptions, it is indeed possible to use higher order moments as a further lensing probe.

  18. Toddlers infer higher-order relational principles in causal learning.

    Science.gov (United States)

    Walker, Caren M; Gopnik, Alison

    2014-01-01

    Children make inductive inferences about the causal properties of individual objects from a very young age. When can they infer higher-order relational properties? In three experiments, we examined 18- to 30-month-olds' relational inferences in a causal task. Results suggest that at this age, children are able to infer a higher-order relational causal principle from just a few observations and use this inference to guide their own subsequent actions and bring about a novel causal outcome. Moreover, the children passed a revised version of the relational match-to-sample task that has proven very difficult for nonhuman primates. The findings are considered in light of their implications for understanding the nature of relational and causal reasoning, and their evolutionary origins.

  19. Promoting higher order thinking skills using inquiry-based learning

    Science.gov (United States)

    Madhuri, G. V.; S. S. N Kantamreddi, V.; Goteti, L. N. S. Prakash

    2012-05-01

    Active learning pedagogies play an important role in enhancing higher order cognitive skills among the student community. In this work, a laboratory course for first year engineering chemistry is designed and executed using an inquiry-based learning pedagogical approach. The goal of this module is to promote higher order thinking skills in chemistry. Laboratory exercises are designed based on Bloom's taxonomy and a just-in-time facilitation approach is used. A pre-laboratory discussion outlining the theory of the experiment and its relevance is carried out to enable the students to analyse real-life problems. The performance of the students is assessed based on their ability to perform the experiment, design new experiments and correlate practical utility of the course module with real life. The novelty of the present approach lies in the fact that the learning outcomes of the existing experiments are achieved through establishing a relationship with real-world problems.

  20. Higher order relativistic galaxy number counts: dominating terms

    CERN Document Server

    Nielsen, Jeppe Trøst

    2016-01-01

    We review the number counts to second order concentrating on the terms which dominate on sub horizon scales. We re-derive the result for these terms and compare it with the different versions found in the literature. We generalize our derivation to higher order terms, especially the third order number counts which are needed to compute the 1-loop contribution to the power spectrum.

  1. 1957-2007: 50 Years of Higher Order Programming Languages

    OpenAIRE

    Alen Lovrenčić; Mario Konecki; Tihomir Orehovački

    2009-01-01

    Fifty years ago one of the greatest breakthroughs in computer programming and in the history of computers happened -- the appearance of FORTRAN, the first higher-order programming language. From that time until now hundreds of programming languages were invented, different programming paradigms were defined, all with the main goal to make computer programming easier and closer to as many people as possible. Many battles were fought among scientists as well as among developers around concepts ...

  2. Graph rewriting with polarized cloning

    CERN Document Server

    Duval, Dominique; Prost, Frédéric

    2009-01-01

    We tackle the problem of graph transformation with a particular focus on node cloning. We propose a graph rewriting framework where nodes can be cloned zero, one or more times. A node can be cloned together with all its incident edges, with only the outgoing edges, with only the incoming edges or without any of the incident edges. We thus subsume previous works such as the sesqui-pushout, the heterogeneous pushout and the adaptive star grammars approaches. A rule is defined as a span $\\spa{\\grpol{L}}{l}{\\grpol{K}}{r}{R}$ where the right-hand side $R$ is a multigraph, the left-hand side $\\grpol{L}$ and the interface $\\grpol{K}$ are polarized multigraphs. A polarized multigraph is a multigraph endowed with some cloning annotations on nodes and edges. We introduce the notion of polarized multigraphs and define a rewriting step as pushback followed by a pushout in the same way as in the sesqui-pushout approach.

  3. Wave Transformation Modeling with Effective Higher-Order Finite Elements

    Directory of Open Access Journals (Sweden)

    Tae-Hwa Jung

    2016-01-01

    Full Text Available This study introduces a finite element method using a higher-order interpolation function for effective simulations of wave transformation. Finite element methods with a higher-order interpolation function usually employ a Lagrangian interpolation function that gives accurate solutions with a lesser number of elements compared to lower order interpolation function. At the same time, it takes a lot of time to get a solution because the size of the local matrix increases resulting in the increase of band width of a global matrix as the order of the interpolation function increases. Mass lumping can reduce computation time by making the local matrix a diagonal form. However, the efficiency is not satisfactory because it requires more elements to get results. In this study, the Legendre cardinal interpolation function, a modified Lagrangian interpolation function, is used for efficient calculation. Diagonal matrix generation by applying direct numerical integration to the Legendre cardinal interpolation function like conducting mass lumping can reduce calculation time with favorable accuracy. Numerical simulations of regular, irregular and solitary waves using the Boussinesq equations through applying the interpolation approaches are carried out to compare the higher-order finite element models on wave transformation and examine the efficiency of calculation.

  4. Transversely isotropic higher-order averaged structure tensors

    Science.gov (United States)

    Hashlamoun, Kotaybah; Federico, Salvatore

    2017-08-01

    For composites or biological tissues reinforced by statistically oriented fibres, a probability distribution function is often used to describe the orientation of the fibres. The overall effect of the fibres on the material response is accounted for by evaluating averaging integrals over all possible directions in space. The directional average of the structure tensor (tensor product of the unit vector describing the fibre direction by itself) is of high significance. Higher-order averaged structure tensors feature in several models and carry similarly important information. However, their evaluation has a quite high computational cost. This work proposes to introduce mathematical techniques to minimise the computational cost associated with the evaluation of higher-order averaged structure tensors, for the case of a transversely isotropic probability distribution of orientation. A component expression is first introduced, using which a general tensor expression is obtained, in terms of an orthonormal basis in which one of the vectors coincides with the axis of symmetry of transverse isotropy. Then, a higher-order transversely isotropic averaged structure tensor is written in an appropriate basis, constructed starting from the basis of the space of second-order transversely isotropic tensors, which is constituted by the structure tensor and its complement to the identity.

  5. Higher Order Mode Coupler Heating in Continuous Wave Operation

    Science.gov (United States)

    Solyak, N.; Awida, M.; Hocker, A.; Khabibobulline, T.; Lunin, A.

    Electromagnetic heating due to higher order modes (HOM) propagation is particularly a concern for continuous wave (CW) particle accelerator machines. Power on the order of several watts could flow out of the cavity's HOM ports in CW operations. The upgrade of the Linac Coherent Light Source (LCLS-II) at SLAC requires a major modification of the design of the higher order mode (HOM) antenna and feed through of the conventional ILC elliptical 9-cell cavity in order to utilize it for LCLS-II. The HOM antenna is required to bear higher RF losses, while relatively maintaining the coupling level of the higher order modes. In this paper, we present a detailed analysis of the heating expected in the HOM coupler with a thorough thermal quench study in comparison with the conventional ILC design. We discuss also how the heat will be removed from the cavity through RF cables with specially designed cooling straps. Finally, we report on the latest experimental results of cavity testing in vertical and horizontal cryostats.

  6. Mapping Modular SOS to Rewriting Logic

    DEFF Research Database (Denmark)

    Braga, Christiano de Oliveira; Haeusler, Erik Hermann; Meseguer, José;

    Modular SOS (MSOS) is a framework created to improve the modularity of structural operational semantics specifications, a formalism frequently used in the fields of programming languages semantics and process algebras. With the objective of defining formal tools to support the execution and verif......-performance implementation of RWL. In this paper we characterize the mapping and the MSOS-SL Interpreter. The reader is assumed to have some basic knowledge of structural operational semantics and object-oriented concepts....... and verification of MSOS specifications, we have defined a mapping, named , from MSOS to rewriting logic (RWL), a logic which has been proposed as a logical and semantic framework. We have proven the correctness of and implemented it as a prototype, the MSOS-SL Interpreter, in the Maude system, a high...

  7. Elementary Particle Spectroscopy in Regular Solid Rewrite

    Science.gov (United States)

    Trell, Erik

    2008-10-01

    The Nilpotent Universal Computer Rewrite System (NUCRS) has operationalized the radical ontological dilemma of Nothing at All versus Anything at All down to the ground recursive syntax and principal mathematical realisation of this categorical dichotomy as such and so governing all its sui generis modalities, leading to fulfilment of their individual terms and compass when the respective choice sequence operations are brought to closure. Focussing on the general grammar, NUCRS by pure logic and its algebraic notations hence bootstraps Quantum Mechanics, aware that it "is the likely keystone of a fundamental computational foundation" also for e.g. physics, molecular biology and neuroscience. The present work deals with classical geometry where morphology is the modality, and ventures that the ancient regular solids are its specific rewrite system, in effect extensively anticipating the detailed elementary particle spectroscopy, and further on to essential structures at large both over the inorganic and organic realms. The geodetic antipode to Nothing is extension, with natural eigenvector the endless straight line which when deployed according to the NUCRS as well as Plotelemeian topographic prescriptions forms a real three-dimensional eigenspace with cubical eigenelements where observed quark-skewed quantum-chromodynamical particle events self-generate as an Aristotelean phase transition between the straight and round extremes of absolute endlessness under the symmetry- and gauge-preserving, canonical coset decomposition SO(3)×O(5) of Lie algebra SU(3). The cubical eigen-space and eigen-elements are the parental state and frame, and the other solids are a range of transition matrix elements and portions adapting to the spherical root vector symmetries and so reproducibly reproducing the elementary particle spectroscopy, including a modular, truncated octahedron nano-composition of the Electron which piecemeal enter into molecular structures or compressed to each

  8. Proper orthogonal decomposition-based spectral higher-order stochastic estimation

    Energy Technology Data Exchange (ETDEWEB)

    Baars, Woutijn J., E-mail: wbaars@unimelb.edu.au [Department of Mechanical Engineering, The University of Melbourne, Melbourne, Victoria 3010 (Australia); Tinney, Charles E. [Center for Aeromechanics Research, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2014-05-15

    A unique routine, capable of identifying both linear and higher-order coherence in multiple-input/output systems, is presented. The technique combines two well-established methods: Proper Orthogonal Decomposition (POD) and Higher-Order Spectra Analysis. The latter of these is based on known methods for characterizing nonlinear systems by way of Volterra series. In that, both linear and higher-order kernels are formed to quantify the spectral (nonlinear) transfer of energy between the system's input and output. This reduces essentially to spectral Linear Stochastic Estimation when only first-order terms are considered, and is therefore presented in the context of stochastic estimation as spectral Higher-Order Stochastic Estimation (HOSE). The trade-off to seeking higher-order transfer kernels is that the increased complexity restricts the analysis to single-input/output systems. Low-dimensional (POD-based) analysis techniques are inserted to alleviate this void as POD coefficients represent the dynamics of the spatial structures (modes) of a multi-degree-of-freedom system. The mathematical framework behind this POD-based HOSE method is first described. The method is then tested in the context of jet aeroacoustics by modeling acoustically efficient large-scale instabilities as combinations of wave packets. The growth, saturation, and decay of these spatially convecting wave packets are shown to couple both linearly and nonlinearly in the near-field to produce waveforms that propagate acoustically to the far-field for different frequency combinations.

  9. Exponential Lower Bounds and Separation for Query Rewriting

    CERN Document Server

    Kikot, Stanislav; Podolskii, Vladimir; Zakharyaschev, Michael

    2012-01-01

    We establish connections between the size of circuits and formulas computing monotone Boolean functions and the size of first-order and nonrecursive Datalog rewritings for conjunctive queries over OWL 2 QL ontologies. We use known lower bounds and separation results from circuit complexity to prove similar results for the size of rewritings that do not use non-signature constants. For example, we show that, in the worst case, positive existential and nonrecursive Datalog rewritings are exponentially longer than the original queries; nonrecursive Datalog rewritings are in general exponentially more succinct than positive existential rewritings; while first-order rewritings can be superpolynomially more succinct than positive existential rewritings.

  10. Stability and convergence of a higher order rational difference Equation

    CERN Document Server

    Gazor, Hamid

    2011-01-01

    In this paper the asymptotic stability of equilibria and periodic points of the following higher order rational difference Equation x_{n+1} =(alpha x_{n-k})/(1+x_{n}...x_{n-k}), k>=1, n=0,1,... is studied where the parameters ?alpha, betta, and gamma are positive real numbers, and the initial conditions x_{-k}, ..., x_{0} are given arbitrary real numbers. The forbidden set of this equation is found and then, the order reduction method is used to facilitate the analysis of its asymptotic dynamics

  11. Radiation by solitons due to higher-order dispersion

    DEFF Research Database (Denmark)

    Karpman, V.I.

    1993-01-01

    We consider the Korteweg-de Vries (KdV) and nonlinear Schrodinger (NS) equations with higher-order derivative terms describing dispersive corrections. Conditions of existence of stationary and radiating solitons of the fifth-order KdV equation are obtained. An asymptotic time-dependent solution...... to the latter equation, describing the soliton radiation, is found. The radiation train may be in front as well as behind the soliton, depending on the sign of dispersion. The change rate of the soliton due to the radiation is calculated. A modification of the WKB method, that permits one to describe...

  12. Higher-order photon correlations in pulsed photonic crystal nanolasers

    CERN Document Server

    Elvira, David; Verma, V; Braive, Remy; Beaudoin, Gregoire; Robert-Philip, Isabelle; Sagnes, Isabelle; Baek, Burm; Nam, Sae Woo; Dauler, Eric A; Abram, Izo; Stevens, Martin J; Beveratos, Alexios

    2011-01-01

    We report on the higher-order photon correlations of a high-$\\beta$ nanolaser under pulsed excitation at room temperature. Using a multiplexed four-element superconducting single photon detector we measured g$^{(n)}(\\vec{0})$ with $n$=2,3,4. All orders of correlation display partially chaotic statistics, even at four times the threshold excitation power. We show that this departure from coherence and Poisson statistics is due to the quantum fluctuations associated with the small number of dipoles and photons involved in the lasing process.

  13. A higher-order duration calculus and its completeness

    Institute of Scientific and Technical Information of China (English)

    詹乃军

    2000-01-01

    This paper studies how to describe the real-time behaviour of programs using duration calculus. Since program variables are interpreted as functions over time in real-time programming, and it is inevitable to introduce quantifications over program variables in order to describe local variable declaration and declare local channel and so on. Therefore to establish a higher-order duration calculus (HDC) is necessary. We first establish HDC, then show some real-time properties of programs in terms of HDC, and then, prove that HDC is complete on abstract domains under the assumption that all program variables vary finitely.

  14. Higher-Order Separation Logic in Isabelle/HOLCF

    DEFF Research Database (Denmark)

    Varming, Carsten; Birkedal, Lars

    2008-01-01

    language. This follows the definitional approach common in HOL theorem provers, i.e., the soundness of our model only relies on the soundness of Isabelle/HOL [6]. We use our formalization to give a formally verified proof of Cheney's copying garbage collector [4] using a tagged representation of objects....... The proof generalizes the results in [2]. The proof uses an encoding of the separation logic formula this(h) to capture the heap from before the garbage collection and thus shows another novel use of higher-order separation logic....

  15. Femtosecond filamentation in air and higher-order nonlinearities

    CERN Document Server

    Kolesik, M; Moloney, J V

    2010-01-01

    According to a recent experiment, the instantaneous electronic Kerr effect in air exhibits a strong intensity dependence, the nonlinear refractive index switching sign and crossing over from a self-focusing to a de-focusing nonlinearity. A subsequent theoretical work has demonstrated that this has paradigm-changing consequences for the understanding of filamentation in air, so it is important to subject the idea of higher-order nonlinearities to stringent tests. Here we use numerical modeling to propose an experiment capable of discriminating between the standard and the new intensity-dependent Kerr-effect models.

  16. Contingentism about Individuals and Higher-Order Necessitism

    Directory of Open Access Journals (Sweden)

    Manuel Pérez Otero

    2013-09-01

    Full Text Available Necessitism about individuals claims that necessarily every individual necessarily exists. An analogous necessitist thesis attributes necessary existence to properties and relations. Both theses have been defended by Williamson. Furthermore, Williamson specifically argues against the hybrid conjunction of first-order contingentism (the negation of necessitism about individuals and higher-order necessitism; a combination that would bring about additional drawbacks. I work out a defence of the hybrid combination, including some replies to Williamson’s additional objections. Considerations of ontological parsimony and pre-theoretical intuitions favour the hybrid view over necessitism at all orders (which Williamson mainly defends by invoking considerations of simplicity.

  17. Isotropic Stars in Higher-Order Torsion Scalar Theories

    Directory of Open Access Journals (Sweden)

    Gamal G. L. Nashed

    2016-01-01

    Full Text Available Two different nondiagonal tetrad spaces reproducing spherically symmetric spacetime are applied to the field equations of higher-order torsion scalar theories. Assuming the existence of conformal Killing vector, two isotropic solutions are derived. We show that the first solution is not stable while the second one confirms a stable behavior. We also discuss the construction of the stellar model and show that one of our solutions is capable of such construction while the other is not. Finally, we discuss the generalized Tolman-Oppenheimer-Volkoff and show that one of our models has a tendency to equilibrium.

  18. Isotropic stars in higher-order torsion scalar theories

    CERN Document Server

    Nashed, Gamal G L

    2016-01-01

    Two tetrad spaces reproducing spherically symmetric spacetime are applied to the equations of motion of higher-order torsion theories. Assuming the existence of conformal Killing vector, two isotropic solutions are derived. We show that the first solution is not stable while the second one confirms a stable behavior. We also discuss the construction of the stellar model and show that one of our solution capable of such construction while the other cannot. Finally, we discuss the generalized Tolman-Oppenheimer-Volkoff and show that one of our models has a tendency to equilibrium.

  19. Squeezing of higher order Hermite-Gauss modes

    DEFF Research Database (Denmark)

    Lassen, Mikael Østergaard

    2008-01-01

    The present paper gives an overview of the experimental generation of squeezing in higher order Hermite-Gaussian modes with an optical parametric ampli¯er (OPA). This work was awarded with The European Optical Society (EOS) price 2007. The purpose of the prize is to encourage a European dimension...... in research in pure and applied optics. The EOS prize is awarded based on the selection criteria of high professionalism, academic and technical quality. Following the EOS Prize rules, the conditions for eligibility are that the work was performed in Europe and that it is published under the auspices...

  20. Higher-order polarization singularitites in tailored vector beams

    Science.gov (United States)

    Otte, E.; Alpmann, C.; Denz, C.

    2016-07-01

    Higher-order polarization singularities embedded in tailored vector beams are introduced and experimentally realized. As holographic modulation allows to define order and location of any vectorial singularity, the surrounding vector field can be dynamically shaped. We demonstrate light fields associated with flowers or spider webs due to regular and even irregular patterns of the orientation of polarization ellipses. Beyond that, not yet investigated hybrid structures are introduced that allow generating networks of flowers and webs in very close vicinity. Our results pave the way to applications of singular optics in spatially extended, optimized optical tweezing and high-resolution imaging.

  1. Higher-order-mode fiber optimized for energetic soliton propagation.

    Science.gov (United States)

    Pedersen, Martin E V; Cheng, Ji; Charan, Kriti; Wang, Ke; Xu, Chris; Grüner-Nielsen, Lars; Jakobsen, Dan

    2012-08-15

    We describe the design optimization of a higher-order-mode (HOM) fiber for energetic soliton propagation at wavelengths below 1300 nm. A new HOM fiber is fabricated according to our design criteria. The HOM fiber is pumped at 1045 nm by an energetic femtosecond fiber laser. The soliton self-frequency shift process shifts the center wavelength of the soliton to 1085 nm. The soliton has a temporal duration of 216 fs and a pulse energy of 6.3 nJ. The demonstrated pulse energy is approximately six times higher than the previous record in a solid core fiber at wavelengths below 1300 nm.

  2. Higher Order Mode Properties of Superconducting Two-Spoke Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Hopper, C. S.; Delayen, J. R.; Olave, R. G.

    2011-07-01

    Multi-Spoke cavities lack the cylindrical symmetry that many other cavity types have, which leads to a more complex Higher Order Mode (HOM) spectrum. In addition, spoke cavities offer a large velocity acceptance which means we must perform a detailed analysis of the particle velocity dependence for each mode's R/Q. We present here a study of the HOM properties of two-spoke cavities designed for high-velocity applications. Frequencies, R/Q and field profiles of HOMs have been calculated and are reported.

  3. Higher-order chaotic oscillator using active bessel filter

    DEFF Research Database (Denmark)

    Lindberg, Erik; Mykolaitis, Gytis; Bumelien, Skaidra;

    2010-01-01

    A higher-order oscillator, including a nonlinear unit and an 8th-order low-pass active Bessel filter is described. The Bessel unit plays the role of "three-in-one": a delay line, an amplifier and a filter. Results of hardware experiments and numerical simulation are presented. Depending on the pa...... on the parameters of the nonlinear unit the oscillator operates either in a one-scroll or two-scroll mode. Two positive Lyapunov exponents, found at larger values of the negative slopes of the nonlinear function, characterize the oscillations as hyperchaotic....

  4. Chaotic Time Series Forecasting Using Higher Order Neural Networks

    Directory of Open Access Journals (Sweden)

    Waddah Waheeb

    2016-10-01

    Full Text Available This study presents a novel application and comparison of higher order neural networks (HONNs to forecast benchmark chaotic time series. Two models of HONNs were implemented, namely functional link neural network (FLNN and pi-sigma neural network (PSNN. These models were tested on two benchmark time series; the monthly smoothed sunspot numbers and the Mackey-Glass time-delay differential equation time series. The forecasting performance of the HONNs is compared against the performance of different models previously used in the literature such as fuzzy and neural networks models. Simulation results showed that FLNN and PSNN offer good performance compared to many previously used hybrid models.

  5. Time-Discrete Higher-Order ALE Formulations: Stability

    KAUST Repository

    Bonito, Andrea

    2013-01-01

    Arbitrary Lagrangian Eulerian (ALE) formulations deal with PDEs on deformable domains upon extending the domain velocity from the boundary into the bulk with the purpose of keeping mesh regularity. This arbitrary extension has no effect on the stability of the PDE but may influence that of a discrete scheme. We examine this critical issue for higher-order time stepping without space discretization. We propose time-discrete discontinuous Galerkin (dG) numerical schemes of any order for a time-dependent advection-diffusion-model problem in moving domains, and study their stability properties. The analysis hinges on the validity of the Reynold\\'s identity for dG. Exploiting the variational structure and assuming exact integration, we prove that our conservative and nonconservative dG schemes are equivalent and unconditionally stable. The same results remain true for piecewise polynomial ALE maps of any degree and suitable quadrature that guarantees the validity of the Reynold\\'s identity. This approach generalizes the so-called geometric conservation law to higher-order methods. We also prove that simpler Runge-Kutta-Radau methods of any order are conditionally stable, that is, subject to a mild ALE constraint on the time steps. Numerical experiments corroborate and complement our theoretical results. © 2013 Society for Industrial and Applied Mathematics.

  6. Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes

    Energy Technology Data Exchange (ETDEWEB)

    Geddes, C.G.R.; Cormier-Michel, E.; Esarey, E.; Schroeder, C.B.; Mullowney, P.; Paul, K.; Cary, J.R.; Leemans, W.P.

    2010-06-01

    Laser-plasma collider designs point to staging of multiple accelerator stages at the 10 GeV level, which are to be developed on the upcoming BELLA laser, while Thomson Gamma source designs use GeV stages, both requiring efficiency and low emittance. Design and scaling of stages operating in the quasi-linear regime to address these needs are presented using simulations in the VORPAL framework. In addition to allowing symmetric acceleration of electrons and positrons, which is important for colliders, this regime has the property that the plasma wakefield is proportional to the transverse gradient of the laser intensity profile. We demonstrate use of higher order laser modes to tailor the laser pulse and hence the transverse focusing forces in the plasma. In particular, we show that by using higher order laser modes, we can reduce the focusing fields and hence increase the matched electron beam radius, which is important to increased charge and efficiency, while keeping the low bunch emittance required for applications.

  7. Ontological Queries: Rewriting and Optimization (Extended Version)

    CERN Document Server

    Gottlob, Georg; Pieris, Andreas

    2011-01-01

    Ontological queries are evaluated against an ontology rather than directly on a database. The evaluation and optimization of such queries is an intriguing new problem for database research. In this paper we discuss two important aspects of this problem: query rewriting and query optimization. Query rewriting consists of the compilation of an ontological query into an equivalent query against the underlying relational database. The focus here is on soundness and completeness. We review previous results and present a new rewriting algorithm for rather general types of ontological constraints. In particular, we show how a conjunctive query against an ontology can be compiled into a union of conjunctive queries against the underlying database. Ontological query optimization, in this context, attempts to improve this process so to produce possibly small and cost-effective UCQ rewritings for an input query. We review existing optimization methods, and propose an effective new method that works for linear Datalog+/-...

  8. Chemical Freeze-Out and Higher Order Multiplicity Moments

    CERN Document Server

    Tawfik, A

    2013-01-01

    We calculate the non-normalized moments of the particle multiplicity within the framework of the hadron resonance gas (HRG) model. At finite chemical potential $\\mu$, a non-monotonic behavior is observed in the thermal evolution of third order moment (skewness $S$) and the higher order ones as well. Among others, this observation likely reflects dynamical fluctuations and strong correlations. The signatures of non-monotonicity in the normalized fourth order moment (kurtosis $\\kappa$) and its products get very clear. Based on these findings, we introduce a novel condition characterizing the universal freeze-out curve. The chemical freeze-out parameters $T$ and $\\mu$ are described by vanishing $\\kappa\\, \\sigma^2$ or equivalently $m_4=3\\,\\chi^2$, where $\\sigma$, $\\chi$ and $m_4$ are the standard deviation, susceptibility and fourth order moment, respectively. The fact that the HRG model is not able to release information about criticality related to the confinement and chiral dynamics should not veil the observa...

  9. Higher Order Variability Properties of Accreting Black Holes

    CERN Document Server

    Maccarone, T J; Maccarone, Thomas J.; Coppi, Paolo S.

    2002-01-01

    To better constrain the emission mechanism underlying the hard state of galactic black hole candidates, we use high-time resolution RXTE lightcurves for Cyg X-1 and GX 399-4 to compute two higher order variability statistics for these objects, the skewness and the Fourier bispectrum. Similar analyses, in particular using the skewness measure, have been attempted before, but the photon collection area of RXTE allows us to present results of much greater statistical significance. The results for the two objects are qualitatively similar, reinforcing the idea that the same basic mechanisms are at work in both. We find a significantly positive skewness for variability timescales less than $\\sim 1 $ second, and a {\\it negative} skewness for timescale $1- 5 $ sec. Such a skewness pattern cannot be reproduced by the simplest shot variability models where individual shots have a fixed profile and intensity and are uncorrelated in time. Further evidence against simple shot models comes from the significant detection o...

  10. SU(2) Higher-order effective quark interactions from polarization

    Science.gov (United States)

    Braghin, Fábio L.

    2016-10-01

    Higher order quark effective interactions are found for SU(2) flavor by departing from a non-local quark-quark interaction. By integrating out a component of the quark field, the determinant is expanded in chirally symmetric and symmetry breaking effective interactions up to the fifth order in the quark bilinears. The resulting coupling constants are resolved in the leading order of the longwavelength limit and exact numerical ratios between several of these coupling constants are obtained in the large quark mass limit. In this level, chiral invariant interactions only show up in even powers of the quark bilinears, i.e. O(ψ bar ψ) 2 n (n = 1 , 2 , 3 , . .), whereas (explicit) chiral symmetry breaking terms emerge as O(ψ bar ψ) n being always proportional to some power of the Lagrangian quark mass.

  11. Higher-order nonlinear effects in a Josephson parametric amplifier

    Science.gov (United States)

    Kochetov, Bogdan A.; Fedorov, Arkady

    2015-12-01

    Nonlinearity of the current-phase relationship of a Josephson junction is the key resource for a Josephson parametric amplifier (JPA) as well as for a Josephson traveling-wave parametric amplifier, the only devices in which the quantum limit for added noise has so far been approached at microwave frequencies. A standard approach to describe JPA takes into account only the lowest order (cubic) nonlinearity resulting in a Duffing-like oscillator equation of motion or in a Kerr-type nonlinearity term in the Hamiltonian. In this paper we derive the quantum expression for the gain of JPA including all orders of the Josephson junction nonlinearity in the linear response regime. We then analyze gain saturation effect for stronger signals within a semiclassical approach. Our results reveal nonlinear effects of higher orders and their implications for operation of a JPA.

  12. Podolsky`s higher-order electromagnetism from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Accioly, A. [Sao Paulo, Univ. Estadual Paulista (Brazil). Instituto de Fisica Teorica; Mukai, H. [Maringa, Fundacao Universidade Estadual de Maringa (Brazil). Dept. de Fisica

    1997-07-01

    Podolsky`s higher-order field equations are obtained by generalizing the laws of Podolsky`s electrostatics, which follow from Coulomb`s generalized law and superposition, to be consistent with special relativity. In addition, it is necessary to take into account the independence of the observed charge of a particle on tis speed. It is also shown that the gauge-independent term concerning the Feynman propagator for Podolsky`s generalized electrodynamics has a good ultraviolet behaviour at the expense of a negative metric massive ghost which, contrary to what is currently assumed in the literature, is non-tachyonic. A brief discussion on Podolsky`s characteristic length is presented as well.

  13. Polymer quantization, stability and higher-order time derivative terms

    CERN Document Server

    Cumsille, Patricio; Ossandon, Sebastian; Reyes, Camilo

    2015-01-01

    The stability of higher-order time derivative theories using the polymer extension of quantum mechanics is studied. First, we focus on the well-known Pais-Uhlenbeck model and by casting the theory into the sum of two decoupled harmonic oscillators we show that the energy spectrum is composed with positive and negative energy parts. The Schrodinger quantization of the model with creation and annihilations operators leads to a theory with unbounded Hamiltonian that can be interpreted in terms of normal particles and Lee-Wick-like particles responsible for the instability. We investigate whether the fundamental discreetness implicit in the polymer quantization can regularize the effects of the negative energies introduced by the Lee-Wick-like particles which are associated to a high-energy scale. Precisely, we show that the polymer quantization leads to a positive defined Hamiltonian whose stability is improved as the number of Lee-Wick-like particles grows.

  14. Neutron scattering studies on chromatin higher-order structure

    Energy Technology Data Exchange (ETDEWEB)

    Graziano, V.; Gerchman, S.E.; Schneider, D.K.; Ramakrishnan, V. [Brookhaven National Laboratory, Upton, NY (United States)

    1994-12-31

    We have been engaged in studies of the structure and condensation of chromatin into the 30nm filament using small-angle neutron scattering. We have also used deuterated histone H1 to determine its location in the chromatin 30nm filament. Our studies indicate that chromatin condenses with increasing ionic strength to a limiting structure that has a mass per unit length of 6-7 nucleosomes/11 nm. They also show that the linker histone H1/H5 is located in the interior of the chromatin filament, in a position compatible with its binding to the inner face of the nucleosome. Analysis of the mass per unit length as a function of H5 stoichiometry suggests that 5-7 contiguous nucleosomes need to have H5 bound before a stable higher order structure can exist.

  15. Higher order mode propagation in nonuniform circular ducts

    Science.gov (United States)

    Cho, Y. C.; Ingard, K. U.

    1980-01-01

    This paper presents an analytical investigation of higher order mode propagation in a nonuniform circular duct without mean flow. An approximate wave equation is derived on the assumptions that the duct cross section varies slowly and that mode conversion is negligible. Exact closed form solutions are obtained for a particular class of converging-diverging circular duct which is here referred to as 'circular cosh duct'. Numerical results are presentd in terms of the transmission loss for the various duct shapes and frequencies. The results are applicable to studies of multimodal propagation as well as single mode propagation. The results are also applicable to studies of sound radiation from certain types of contoured inlet ducts, or of sound propagation in a converging-diverging duct of somewhat different shape from a cosh duct.

  16. Higher order branching of periodic orbits from polynomial isochrones

    Directory of Open Access Journals (Sweden)

    B. Toni

    1999-09-01

    Full Text Available We discuss the higher order local bifurcations of limit cycles from polynomial isochrones (linearizable centers when the linearizing transformation is explicitly known and yields a polynomial perturbation one-form. Using a method based on the relative cohomology decomposition of polynomial one-forms complemented with a step reduction process, we give an explicit formula for the overall upper bound of branch points of limit cycles in an arbitrary $n$ degree polynomial perturbation of the linear isochrone, and provide an algorithmic procedure to compute the upper bound at successive orders. We derive a complete analysis of the nonlinear cubic Hamiltonian isochrone and show that at most nine branch points of limit cycles can bifurcate in a cubic polynomial perturbation. Moreover, perturbations with exactly two, three, four, six, and nine local families of limit cycles may be constructed.

  17. Higher order numerical differentiation on the Infinity Computer

    CERN Document Server

    Sergeyev, Yaroslav D

    2012-01-01

    There exist many applications where it is necessary to approximate numerically derivatives of a function which is given by a computer procedure. In particular, all the fields of optimization have a special interest in such a kind of information. In this paper, a new way to do this is presented for a new kind of a computer -- the Infinity Computer -- able to work numerically with finite, infinite, and infinitesimal numbers. It is proved that the Infinity Computer is able to calculate values of derivatives of a higher order for a wide class of functions represented by computer procedures. It is shown that the ability to compute derivatives of arbitrary order automatically and accurate to working precision is an intrinsic property of the Infinity Computer related to its way of functioning. Numerical examples illustrating the new concepts and numerical tools are given.

  18. Higher Order Reentrant Post Modes in Cylindrical Cavities

    CERN Document Server

    McAllister, Ben T; Parker, Stephen R; Tobar, Michael E

    2016-01-01

    Reentrant cavities are microwave resonant devices employed in a number of different areas of physics. They are appealing due to their simple frequency tuning mechanism, which offers large tuning ranges. Reentrant cavities are, in essence, 3D lumped LC circuits consisting of a conducting central post embedded in a resonant cavity. The lowest order reentrant mode (which transforms from the TM010 mode) has been extensively studied in past publications. In this work we show the existence of higher order reentrant post modes (which transform from the TM01n mode family). We characterize these new modes in terms of their frequency tuning, filling factors and quality factors, as well as discuss some possible applications of these modes in fundamental physics tests.

  19. Mixed Higher Order Variational Model for Image Recovery

    Directory of Open Access Journals (Sweden)

    Pengfei Liu

    2014-01-01

    Full Text Available A novel mixed higher order regularizer involving the first and second degree image derivatives is proposed in this paper. Using spectral decomposition, we reformulate the new regularizer as a weighted L1-L2 mixed norm of image derivatives. Due to the equivalent formulation of the proposed regularizer, an efficient fast projected gradient algorithm combined with monotone fast iterative shrinkage thresholding, called, FPG-MFISTA, is designed to solve the resulting variational image recovery problems under majorization-minimization framework. Finally, we demonstrate the effectiveness of the proposed regularization scheme by the experimental comparisons with total variation (TV scheme, nonlocal TV scheme, and current second degree methods. Specifically, the proposed approach achieves better results than related state-of-the-art methods in terms of peak signal to ratio (PSNR and restoration quality.

  20. Evidence for several higher order structural elements in ribosomal RNA.

    Science.gov (United States)

    Woese, C R; Gutell, R R

    1989-05-01

    Comparative analysis of small subunit ribosomal RNA sequences suggests the existence of two new higher order interactions: (i) a double-helical structure involving positions 505-507 and 524-526 (Escherichia coli numbering) and (ii) an interaction between the region of position 130 and the helix located approximately between positions 180 and 195. In the first of these, one of the strands of the helix exists in the bulge loop, and the other strand exists in the terminal loop of a previously recognized compound helix involving positions 500-545. Therefore, the new structure formally represents a pseudoknot. In the second, the insertion/deletion of a nucleotide in the vicinity of position 130 correlates with the length of the helix in the 180-195 region, the latter having a 3-base-pair stalk when the base in question is deleted and a stalk of approximately 10 pairs when it is inserted.

  1. Inflationary scenarios in Starobinsky model with higher order corrections

    Energy Technology Data Exchange (ETDEWEB)

    Artymowski, Michał [Institute of Physics, Jagiellonian University,Łojasiewicza 11, 30-348 Kraków (Poland); Lalak, Zygmunt [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Lewicki, Marek [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Michigan Center for Theoretical Physics, University of Michigan,450 Church Street, Ann Arbor MI 48109 (United States)

    2015-06-17

    We consider the Starobinsky inflation with a set of higher order corrections parametrised by two real coefficients λ{sub 1} ,λ{sub 2}. In the Einstein frame we have found a potential with the Starobinsky plateau, steep slope and possibly with an additional minimum, local maximum or a saddle point. We have identified three types of inflationary behaviour that may be generated in this model: i) inflation on the plateau, ii) at the local maximum (topological inflation), iii) at the saddle point. We have found limits on parameters λ{sub i} and initial conditions at the Planck scale which enable successful inflation and disable eternal inflation at the plateau. We have checked that the local minimum away from the GR vacuum is stable and that the field cannot leave it neither via quantum tunnelling nor via thermal corrections.

  2. Research on Life Signals Detection Based on Higher Order Statistics

    Directory of Open Access Journals (Sweden)

    Jian-Jun Li

    2012-10-01

    Full Text Available The life signals are built on harmonic mode for their low frequency, quasi-periodicity, low SNR, and the easy submerged in strong clutter noise. The method for detecting life signal based on adaptive filter and high order statistics is presented, in which neither the Gaussian supposition of the observed signal, nor a prior information about the waveform and arrival time of the observed signal is necessary. The principle of method is to  separate the spectrum of input signal into many narrow frequency bands, whose Sub-band signal  is followed by a short-time estimation of higher-order statistics so as to suppress Gaussian noises. Simulated results show that the method can effectively detect life signals from noise with good convergence speed and stability, and greatly improve the signal quality with respect to LMS method.

  3. Higher order mode analysis of the SPL cavities

    CERN Document Server

    Schuh, M; Tuckmantel, J; Welsch, CP

    2010-01-01

    Higher Order Modes (HOMs) can severely limit the operation of superconducting cavities in a linac with high beam current, high duty factor and complex pulse structure. The full HOM spectrum has to be analyzed in order to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam simulation code focused on beam-HOMinteraction was developed, taking into account important effects like the HOMfrequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. Here, the code is used to investigate in detail the HOM properties of the cavities foreseen in the Superconducting Proton Linac (SPL) at CERN and their potential to drive beam instabilities. Special attention is given to HOM excitation by chopped pulses with high repetition rate.

  4. Higher-order structure and epidemic dynamics in clustered networks

    CERN Document Server

    Ritchie, Martin; House, Thomas; Kiss, Istvan Z

    2013-01-01

    Clustering is typically measured by the ratio of triangles to all triples, open or closed. Generating clustered networks, and how clustering affects dynamics on networks, is reasonably well understood for certain classes of networks \\cite{vmclust, karrerclust2010}, e.g., networks composed of lines and non-overlapping triangles. In this paper we show that it is possible to generate networks which, despite having the same degree distribution and equal clustering, exhibit different higher-order structure, specifically, overlapping triangles and other order-four (a closed network motif composed of four nodes) structures. To distinguish and quantify these additional structural features, we develop a new network metric capable of measuring order-four structure which, when used alongside traditional network metrics, allows us to more accurately describe a network's topology. Three network generation algorithms are considered: a modified configuration model and two rewiring algorithms. By generating homogeneous netwo...

  5. Rewriting and suppressing UMLS terms for improved biomedical term identification

    Directory of Open Access Journals (Sweden)

    Hettne Kristina M

    2010-03-01

    Full Text Available Abstract Background Identification of terms is essential for biomedical text mining.. We concentrate here on the use of vocabularies for term identification, specifically the Unified Medical Language System (UMLS. To make the UMLS more suitable for biomedical text mining we implemented and evaluated nine term rewrite and eight term suppression rules. The rules rely on UMLS properties that have been identified in previous work by others, together with an additional set of new properties discovered by our group during our work with the UMLS. Our work complements the earlier work in that we measure the impact on the number of terms identified by the different rules on a MEDLINE corpus. The number of uniquely identified terms and their frequency in MEDLINE were computed before and after applying the rules. The 50 most frequently found terms together with a sample of 100 randomly selected terms were evaluated for every rule. Results Five of the nine rewrite rules were found to generate additional synonyms and spelling variants that correctly corresponded to the meaning of the original terms and seven out of the eight suppression rules were found to suppress only undesired terms. Using the five rewrite rules that passed our evaluation, we were able to identify 1,117,772 new occurrences of 14,784 rewritten terms in MEDLINE. Without the rewriting, we recognized 651,268 terms belonging to 397,414 concepts; with rewriting, we recognized 666,053 terms belonging to 410,823 concepts, which is an increase of 2.8% in the number of terms and an increase of 3.4% in the number of concepts recognized. Using the seven suppression rules, a total of 257,118 undesired terms were suppressed in the UMLS, notably decreasing its size. 7,397 terms were suppressed in the corpus. Conclusions We recommend applying the five rewrite rules and seven suppression rules that passed our evaluation when the UMLS is to be used for biomedical term identification in MEDLINE. A software

  6. Performance of Higher Order Campbell methods, Part II: calibration and experimental application

    Science.gov (United States)

    Elter, Zs.; de Izarra, G.; Filliatre, P.; Jammes, C.; Pázsit, I.

    2016-11-01

    Applying Higher Order Campbelling methods in neutron flux monitoring with fission chambers is advantageous due to their capabilities to suppress the impact of unwanted noises and signal contributions (such as gamma radiation). This work aims to verify through experimental results that the basic assumptions behind the Higher Order Campelling methods are valid in critical reactors. The experiments, reported in this work, were performed at the MINERVE reactor in Cadarache. It is shown that the calibration of a fission chamber and the associated electronic system is possible in higher order mode. With the use of unbiased cumulant estimators and with digital processing, it is shown that over a wide count rate range, accurate count rate estimation can be achieved based on signal samples of a few ms, which is a significant progress compared to similar experimental results in the literature. The difference between the count rate estimated by pulse counting and by the Higher Order Campelling is less than 4%. The work also investigates the possibility of monitoring transient events. For this purpose, a control rod drop event was followed in Higher Order Campbelling mode.

  7. Higher-order-statistics-based radial basis function networks for signal enhancement.

    Science.gov (United States)

    Lin, Bor-Shyh; Lin, Bor-Shing; Chong, Fok-Ching; Lai, Feipei

    2007-05-01

    In this paper, a higher-order-statistics (HOS)-based radial basis function (RBF) network for signal enhancement is introduced. In the proposed scheme, higher order cumulants of the reference signal were used as the input of HOS-based RBF. An HOS-based supervised learning algorithm, with mean square error obtained from higher order cumulants of the desired input and the system output as the learning criterion, was used to adapt weights. The motivation is that the HOS can effectively suppress Gaussian and symmetrically distributed non-Gaussian noise. The influence of a Gaussian noise on the input of HOS-based RBF and the HOS-based learning algorithm can be mitigated. Simulated results indicate that HOS-based RBF can provide better performance for signal enhancement under different noise levels, and its performance is insensitive to the selection of learning rates. Moreover, the efficiency of HOS-based RBF under the nonstationary Gaussian noise is stable.

  8. On the selection of tuning methodology of FOPID controllers for the control of higher order processes.

    Science.gov (United States)

    Das, Saptarshi; Saha, Suman; Das, Shantanu; Gupta, Amitava

    2011-07-01

    In this paper, a comparative study is done on the time and frequency domain tuning strategies for fractional order (FO) PID controllers to handle higher order processes. A new fractional order template for reduced parameter modelling of stable minimum/non-minimum phase higher order processes is introduced and its advantage in frequency domain tuning of FOPID controllers is also presented. The time domain optimal tuning of FOPID controllers have also been carried out to handle these higher order processes by performing optimization with various integral performance indices. The paper highlights on the practical control system implementation issues like flexibility of online autotuning, reduced control signal and actuator size, capability of measurement noise filtration, load disturbance suppression, robustness against parameter uncertainties etc. in light of the above tuning methodologies.

  9. Higher-order adaptive finite-element methods for Kohn-Sham density functional theory

    CERN Document Server

    Motamarri, Phani; Leiter, Kenneth; Knap, Jaroslaw; Gavini, Vikram

    2012-01-01

    We present an efficient computational approach to perform real-space electronic structure calculations using an adaptive higher-order finite-element discretization of Kohn-Sham density-functional theory (DFT).To this end, we develop an \\emph{a priori} mesh adaption technique to construct a close to optimal finite-element discretization of the problem. We further propose an efficient solution strategy for solving the discrete eigenvalue problem by using spectral finite-elements in conjunction with Gauss-Lobatto quadrature, and a Chebyshev acceleration technique for computing the occupied eigenspace. Using the proposed solution procedure, we investigate the computational efficiency afforded by higher-order finite-element discretizations of the Kohn-Sham DFT problem. Our studies suggest that staggering computational savings---of the order of $1000-$fold---can be realized, for both all-electron and pseudopotential calculations, by using higher-order finite-element discretizations. On all the benchmark systems stu...

  10. Technical Decision Making With Higher Order Structure Data: Perspectives on Higher Order Structure Characterization From the Biopharmaceutical Industry.

    Science.gov (United States)

    Weiss, William F; Gabrielson, John P; Al-Azzam, Wasfi; Chen, Guodong; Davis, Darryl L; Das, Tapan K; Hayes, David B; Houde, Damian; Singh, Satish K

    2016-12-01

    Characterization of the higher order structure (HOS) of protein-based biopharmaceutical products is an important aspect of their development. Opinions vary about how best to apply biophysical methods, in which contexts to use these methods, and how to use the resulting data to make technical decisions as drug candidates are commercialized [Gabrielson JP, Weiss WF IV. J Pharm Sci. 2015;104(4):1240-1245]. The aim of this commentary is to provide guidance for the development and implementation of a robust and comprehensive HOS characterization strategy. We first consider important concepts involved in developing a strategy that is appropriately suited to a particular biologic, and then discuss ways industry can partner with academia, technology companies, government laboratories, and regulatory agencies to improve the consistency with which HOS characterization is applied across the biopharmaceutical industry. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  11. Exact Solutions for a Higher-Order Nonlinear Schr(o)dinger Equation in Atmospheric Dynamics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    By giving prior assumptions on the form of the solutions, we succeed to find several exact solutions for a higher-order nonlinear Schrodinger equation derived from one important model in the study of atmospheric and ocean dynamical systems. Our analytical solutions include bright and dark solitary waves, and periodical solutions, which can be used to explain atmospheric phenomena.

  12. Chemical freeze-out and higher order multiplicity moments

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, A., E-mail: a.tawfik@eng.mti.edu.eg

    2014-02-15

    We calculate the non-normalized moments of the particle multiplicity within the framework of the hadron resonance gas (HRG) model. At finite chemical potential μ, a non-monotonic behavior is observed in the thermal evolution of third order moment (skewness S) and the higher order ones as well. The signatures of non-monotonicity in the normalized fourth order moment (kurtosis κ) and its products get very clear. Among others, this observation likely reflects dynamical fluctuations and strong correlations. Based on these findings, we introduce the physics of the universal freeze-out curve. It is found that the chemical freeze-out parameters T and μ are described by vanishing κσ{sup 2} or equivalently m{sub 4}=3χ{sup 2}, where σ, χ and m{sub 4} are the standard deviation, susceptibility and fourth order moment, respectively. The fact that the HRG model is not able to release information about criticality related to the confinement and chiral dynamics should not veil the observations related to the chemical freeze-out. Recent lattice QCD studies strongly advocate the main conclusion of the present paper.

  13. Analytical Higher-Order Model for Flexible and Stretchable Sensors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongfang; ZHU Hongbin; LIU Cheng; LIU Xu; LIU Fuxi; L Yanjun

    2015-01-01

    The stretchable sensor wrapped around a foldable airfoil or embedded inside of it has great potential for use in the monitoring of the structural status of the foldable airfoil. The design methodology is important to the development of the stretchable sensor for status monitoring on the foldable airfoil. According to the requirement of mechanical flexibility of the sensor, the combined use of a layered flexible structural formation and a strain isolation layer is implemented. An analytical higher-order model is proposed to predict the stresses of the strain-isolation layer based on the shear-lag model for the safe design of the flexible and stretchable sensors. The normal stress and shear stress equations in the constructed structure of the sensors are obtained by the proposed model. The stress distribution in the structure is investigated when bending load is applied to the structures. The numerical results show that the proposed model can predict the variation of normal stress and shear stress along the thickness of the strain-isolation (polydimethylsiloxane) layer accurately. The results by the proposed model are in good agreement with the finite element method, in which the normal stress is variable while the shear stress is invariable along the thickness direction of strain-isolation layer. The high-order model is proposed to predict the stresses of the layered structure of the flexible and stretchable sensor for monitoring the status of the foldable airfoil.

  14. Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia.

    Science.gov (United States)

    Choi, Seung Kwon; Chang, Ji Woong

    2016-02-01

    To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia.

  15. Analysis of higher order harmonics with holographic reflection gratings

    Science.gov (United States)

    Mas-Abellan, P.; Madrigal, R.; Fimia, A.

    2017-05-01

    Silver halide emulsions have been considered one of the most energetic sensitive materials for holographic applications. Nonlinear recording effects on holographic reflection gratings recorded on silver halide emulsions have been studied by different authors obtaining excellent experimental results. In this communication specifically we focused our investigation on the effects of refractive index modulation, trying to get high levels of overmodulation that will produce high order harmonics. We studied the influence of the overmodulation and its effects on the transmission spectra for a wide exposure range by use of 9 μm thickness films of ultrafine grain emulsion BB640, exposed to single collimated beams using a red He-Ne laser (wavelength 632.8 nm) with Denisyuk configuration obtaining a spatial frequency of 4990 l/mm recorded on the emulsion. The experimental results show that high overmodulation levels of refractive index produce second order harmonics with high diffraction efficiency (higher than 75%) and a narrow grating bandwidth (12.5 nm). Results also show that overmodulation produce diffraction spectra deformation of the second order harmonic, transforming the spectrum from sinusoidal to approximation of square shape due to very high overmodulation. Increasing the levels of overmodulation of refractive index, we have obtained higher order harmonics, obtaining third order harmonic with diffraction efficiency (up to 23%) and narrowing grating bandwidth (5 nm). This study is the first step to develop a new easy technique to obtain narrow spectral filters based on the use of high index modulation reflection gratings.

  16. A Simplified Algorithm for Inverting Higher Order Diffusion Tensors

    Directory of Open Access Journals (Sweden)

    Laura Astola

    2014-11-01

    Full Text Available In Riemannian geometry, a distance function is determined by an inner product on the tangent space. In Riemann–Finsler geometry, this distance function can be determined by a norm. This gives more freedom on the form of the so-called indicatrix or the set of unit vectors. This has some interesting applications, e.g., in medical image analysis, especially in diffusion weighted imaging (DWI. An important application of DWI is in the inference of the local architecture of the tissue, typically consisting of thin elongated structures, such as axons or muscle fibers, by measuring the constrained diffusion of water within the tissue. From high angular resolution diffusion imaging (HARDI data, one can estimate the diffusion orientation distribution function (dODF, which indicates the relative diffusivity in all directions and can be represented by a spherical polynomial. We express this dODF as an equivalent spherical monomial (higher order tensor to directly generalize the (second order diffusion tensor approach. To enable efficient computation of Riemann–Finslerian quantities on diffusion weighted (DW-images, such as the metric/norm tensor, we present a simple and efficient algorithm to invert even order spherical monomials, which extends the familiar inversion of diffusion tensors, i.e., symmetric matrices.

  17. Higher-order web link analysis using multilinear algebra.

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Joseph P.; Bader, Brett William (Sandia National Laboratories, Albuquerque, NM); Kolda, Tamara Gibson

    2005-07-01

    Linear algebra is a powerful and proven tool in web search. Techniques, such as the PageRank algorithm of Brin and Page and the HITS algorithm of Kleinberg, score web pages based on the principal eigenvector (or singular vector) of a particular non-negative matrix that captures the hyperlink structure of the web graph. We propose and test a new methodology that uses multilinear algebra to elicit more information from a higher-order representation of the hyperlink graph. We start by labeling the edges in our graph with the anchor text of the hyperlinks so that the associated linear algebra representation is a sparse, three-way tensor. The first two dimensions of the tensor represent the web pages while the third dimension adds the anchor text. We then use the rank-1 factors of a multilinear PARAFAC tensor decomposition, which are akin to singular vectors of the SVD, to automatically identify topics in the collection along with the associated authoritative web pages.

  18. Higher-order graph wavelets and sparsity on circulant graphs

    Science.gov (United States)

    Kotzagiannidis, Madeleine S.; Dragotti, Pier Luigi

    2015-08-01

    The notion of a graph wavelet gives rise to more advanced processing of data on graphs due to its ability to operate in a localized manner, across newly arising data-dependency structures, with respect to the graph signal and underlying graph structure, thereby taking into consideration the inherent geometry of the data. In this work, we tackle the problem of creating graph wavelet filterbanks on circulant graphs for a sparse representation of certain classes of graph signals. The underlying graph can hereby be data-driven as well as fixed, for applications including image processing and social network theory, whereby clusters can be modelled as circulant graphs, respectively. We present a set of novel graph wavelet filter-bank constructions, which annihilate higher-order polynomial graph signals (up to a border effect) defined on the vertices of undirected, circulant graphs, and are localised in the vertex domain. We give preliminary results on their performance for non-linear graph signal approximation and denoising. Furthermore, we provide extensions to our previously developed segmentation-inspired graph wavelet framework for non-linear image approximation, by incorporating notions of smoothness and vanishing moments, which further improve performance compared to traditional methods.

  19. The Weak Field Limit of Higher Order Gravity

    CERN Document Server

    Stabile, Arturo

    2008-01-01

    The Higher Order Theories of Gravity - $f(R, R_{\\alpha\\beta}R^{\\alpha\\beta})$ - theory, where $R$ is the Ricci scalar, $R_{\\alpha\\beta}$ is the Ricci tensor and $f$ is any analytic function - have recently attracted a lot of interest as alternative candidates to explain the observed cosmic acceleration, the flatness of the rotation curves of spiral galaxies and other relevant astrophysical phenomena. It is a crucial point testing these alternative theories in the so called weak field and newtonian limit of a $f(R, R_{\\alpha\\beta}R^{\\alpha\\beta})$ - theory. With this "perturbation technique" it is possible to find spherically symmetric solutions and compare them with the ones of General Relativity. On both approaches we found a modification of General Relativity: the behaviour of gravitational potential presents a modification Yukawa - like in the newtonian case and a massive propagation in the weak field case. When the modification of the theory is removed (i.e. $f(R, R_{\\alpha\\beta}R^{\\alpha\\beta}) = R$, Hil...

  20. Effective description of higher-order scalar-tensor theories

    Science.gov (United States)

    Langlois, David; Mancarella, Michele; Noui, Karim; Vernizzi, Filippo

    2017-05-01

    Most existing theories of dark energy and/or modified gravity, involving a scalar degree of freedom, can be conveniently described within the framework of the Effective Theory of Dark Energy, based on the unitary gauge where the scalar field is uniform. We extend this effective approach by allowing the Lagrangian in unitary gauge to depend on the time derivative of the lapse function. Although this dependence generically signals the presence of an extra scalar degree of freedom, theories that contain only one propagating scalar degree of freedom, in addition to the usual tensor modes, can be constructed by requiring the initial Lagrangian to be degenerate. Starting from a general quadratic action, we derive the dispersion relations for the linear perturbations around Minkowski and a cosmological background. Our analysis directly applies to the recently introduced Degenerate Higher-Order Scalar-Tensor (DHOST) theories. For these theories, we find that one cannot recover a Poisson-like equation in the static linear regime except for the subclass that includes the Horndeski and so-called "beyond Horndeski" theories. We also discuss Lorentz-breaking models inspired by Horava gravity.

  1. Predicting perceptual learning from higher-order cortical processing.

    Science.gov (United States)

    Wang, Fang; Huang, Jing; Lv, Yaping; Ma, Xiaoli; Yang, Bin; Wang, Encong; Du, Boqi; Li, Wu; Song, Yan

    2016-01-01

    Visual perceptual learning has been shown to be highly specific to the retinotopic location and attributes of the trained stimulus. Recent psychophysical studies suggest that these specificities, which have been associated with early retinotopic visual cortex, may in fact not be inherent in perceptual learning and could be related to higher-order brain functions. Here we provide direct electrophysiological evidence in support of this proposition. In a series of event-related potential (ERP) experiments, we recorded high-density electroencephalography (EEG) from human adults over the course of learning in a texture discrimination task (TDT). The results consistently showed that the earliest C1 component (68-84ms), known to reflect V1 activity driven by feedforward inputs, was not modulated by learning regardless of whether the behavioral improvement is location specific or not. In contrast, two later posterior ERP components (posterior P1 and P160-350) over the occipital cortex and one anterior ERP component (anterior P160-350) over the prefrontal cortex were progressively modified day by day. Moreover, the change of the anterior component was closely correlated with improved behavioral performance on a daily basis. Consistent with recent psychophysical and imaging observations, our results indicate that perceptual learning can mainly involve changes in higher-level visual cortex as well as in the neural networks responsible for cognitive functions such as attention and decision making.

  2. Degree of musical expertise modulates higher order brain functioning.

    Science.gov (United States)

    Oechslin, Mathias S; Van De Ville, Dimitri; Lazeyras, François; Hauert, Claude-Alain; James, Clara E

    2013-09-01

    Using functional magnetic resonance imaging, we show for the first time that levels of musical expertise stepwise modulate higher order brain functioning. This suggests that degree of training intensity drives such cerebral plasticity. Participants (non-musicians, amateurs, and expert musicians) listened to a comprehensive set of specifically composed string quartets with hierarchically manipulated endings. In particular, we implemented 2 irregularities at musical closure that differed in salience but were both within the tonality of the piece (in-key). Behavioral sensitivity scores (d') of both transgressions perfectly separated participants according to their level of musical expertise. By contrasting brain responses to harmonic transgressions against regular endings, functional brain imaging data showed compelling evidence for stepwise modulation of brain responses by both violation strength and expertise level in a fronto-temporal network hosting universal functions of working memory and attention. Additional independent testing evidenced an advantage in visual working memory for the professionals, which could be predicted by musical training intensity. The here introduced findings of brain plasticity demonstrate the progressive impact of musical training on cognitive brain functions that may manifest well beyond the field of music processing.

  3. A general higher-order remap algorithm for ALE calculations

    Energy Technology Data Exchange (ETDEWEB)

    Chiravalle, Vincent P [Los Alamos National Laboratory

    2011-01-05

    A numerical technique for solving the equations of fluid dynamics with arbitrary mesh motion is presented. The three phases of the Arbitrary Lagrangian Eulerian (ALE) methodology are outlined: the Lagrangian phase, grid relaxation phase and remap phase. The Lagrangian phase follows a well known approach from the HEMP code; in addition the strain rate andflow divergence are calculated in a consistent manner according to Margolin. A donor cell method from the SALE code forms the basis of the remap step, but unlike SALE a higher order correction based on monotone gradients is also added to the remap. Four test problems were explored to evaluate the fidelity of these numerical techniques, as implemented in a simple test code, written in the C programming language, called Cercion. Novel cell-centered data structures are used in Cercion to reduce the complexity of the programming and maximize the efficiency of memory usage. The locations of the shock and contact discontinuity in the Riemann shock tube problem are well captured. Cercion demonstrates a high degree of symmetry when calculating the Sedov blast wave solution, with a peak density at the shock front that is similar to the value determined by the RAGE code. For a flyer plate test problem both Cercion and FLAG give virtually the same velocity temporal profile at the target-vacuum interface. When calculating a cylindrical implosion of a steel shell, Cercion and FLAG agree well and the Cercion results are insensitive to the use of ALE.

  4. Non-rigid registration using higher-order mutual information

    Science.gov (United States)

    Rueckert, D.; Clarkson, M. J.; Hill, D. L. G.; Hawkes, D. J.

    2000-03-01

    Non-rigid registration of multi-modality images is an important tool for assessing temporal and structural changesbetween images. For rigid registration, voxel similarity measures like mutual information have been shown to alignimages from different modalities accurately and robustly. For non-rigid registration, mutual information can besensitive to local variations of intensity which in MR images may be caused by RF inhomogeneity. The reasonfor the sensitivity of mutual information towards intensity variations stems from the fact that mutual informationignores any spatial information. In this paper we propose an extension of the mutual information framework whichincorporates spatial information about higher-order image structure into the registration process and has the potentialto improve the accuracy and robustness of non-rigid registration in the presence of intensity variations. We haveapplied the non-rigid registration algorithm to a number of simulated MR brain images of a digital phantom whichhave been degraded by a simulated intensity shading and a known deformation. In addition, we have applied thealgorithm for the non-rigid registration of eight pre- and post-operative brain MR images which were acquired withan interventional MR scanner and therefore have substantial intensity shading due to RF field inhomogeneities. Inall cases the second-order estimate of mutual information leads to robust and accurate registration.

  5. A higher-order nonlocal elasticity and strain gradient theory and its applications in wave propagation

    Science.gov (United States)

    Lim, C. W.; Zhang, G.; Reddy, J. N.

    2015-05-01

    In recent years there have been many papers that considered the effects of material length scales in the study of mechanics of solids at micro- and/or nano-scales. There are a number of approaches and, among them, one set of papers deals with Eringen's differential nonlocal model and another deals with the strain gradient theories. The modified couple stress theory, which also accounts for a material length scale, is a form of a strain gradient theory. The large body of literature that has come into existence in the last several years has created significant confusion among researchers about the length scales that these various theories contain. The present paper has the objective of establishing the fact that the length scales present in nonlocal elasticity and strain gradient theory describe two entirely different physical characteristics of materials and structures at nanoscale. By using two principle kernel functions, the paper further presents a theory with application examples which relates the classical nonlocal elasticity and strain gradient theory and it results in a higher-order nonlocal strain gradient theory. In this theory, a higher-order nonlocal strain gradient elasticity system which considers higher-order stress gradients and strain gradient nonlocality is proposed. It is based on the nonlocal effects of the strain field and first gradient strain field. This theory intends to generalize the classical nonlocal elasticity theory by introducing a higher-order strain tensor with nonlocality into the stored energy function. The theory is distinctive because the classical nonlocal stress theory does not include nonlocality of higher-order stresses while the common strain gradient theory only considers local higher-order strain gradients without nonlocal effects in a global sense. By establishing the constitutive relation within the thermodynamic framework, the governing equations of equilibrium and all boundary conditions are derived via the variational

  6. Electrospun Photochromic Hybrid Membranes for Flexible Rewritable Media.

    Science.gov (United States)

    Wei, Jing; Jiao, Xiuling; Wang, Ting; Chen, Dairong

    2016-11-02

    Ink-free rewritable media has attracted great attention as a potential alternative to current paper prints, owing to its benefits to reducing paper production and consumption for environmental protection. It is desirable to develop rewritable media based on cheap, robust, and fast-response photochromic systems. Herein, we report the design and fabrication of flexible and photorewritable PVP/a-WO3 hybrid membranes through electrospinning, on which images with high resolution can be photoprinted and heat-erased for over 40 cycles. The well conjugated organic-inorganic hybrid structure endows a fast "electron-proton double injection" from PVP to a-WO3 in the coloration process and greatly improves the photochromic responses. The coloration times can be as short as tens of seconds and the erasure times can be as long as 10 days in ambient conditions. As-formed photochromic membranes are low-cost, environmental benign and easy for large-scale production, indicate their great potential as flexible rewritable media for practical usage.

  7. Threshold resummation and higher order effects in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Ringer, Felix Maximilian

    2015-06-26

    Quantum chromodynamics (QCD) is a quantum field theory that describes the strong interactions between quarks and gluons, the building blocks of all hadrons. Thanks to the experimental progress over the past decades, there has been an ever-growing need for QCD precision calculations for scattering processes involving hadrons. For processes at large momentum transfer, perturbative QCD offers a systematic approach for obtaining precise predictions. This approach relies on two key concepts: the asymptotic freedom of QCD and factorization. In a perturbative calculation at higher orders, the infrared cancellation between virtual and real emission diagrams generally leaves behind logarithmic contributions. In many observables relevant for hadronic scattering these logarithms are associated with a kinematic threshold and are hence known as ''threshold logarithms''. They become large when the available phase space for real gluon emission shrinks. In order to obtain a reliable prediction from QCD, the threshold logarithms need to be taken into account to all orders in the strong coupling constant, a procedure known as ''threshold resummation''. The main focus of my PhD thesis is on studies of QCD threshold resummation effects beyond the next-to-leading logarithmic order. Here we primarily consider the production of hadron pairs in hadronic collisions as an example. In addition, we also consider hadronic jet production, which is particularly interesting for the phenomenology at the LHC. For both processes, we fully take into account the non-trivial QCD color structure of the underlying partonic hard- scattering cross sections. We find that threshold resummation leads to sizable numerical effects in the kinematic regimes relevant for comparisons to experimental data.

  8. 1957-2007: 50 Years of Higher Order Programming Languages

    Directory of Open Access Journals (Sweden)

    Alen Lovrenčić

    2009-06-01

    Full Text Available Fifty years ago one of the greatest breakthroughs in computer programming and in the history of computers happened -- the appearance of FORTRAN, the first higher-order programming language. From that time until now hundreds of programming languages were invented, different programming paradigms were defined, all with the main goal to make computer programming easier and closer to as many people as possible. Many battles were fought among scientists as well as among developers around concepts of programming, programming languages and paradigms. It can be said that programming paradigms and programming languages were very often a trigger for many changes and improvements in computer science as well as in computer industry. Definitely, computer programming is one of the cornerstones of computer science.Today there are many tools that give a help in the process of programming, but there is still a programming tasks that can be solved only manually. Therefore, programming is still one of the most creative parts of interaction with computers.Programmers should chose programming language in accordance to task they have to solve, but very often, they chose it in accordance to their personal preferences, their beliefs and many other subjective reasons.Nevertheless, the market of programming languages can be merciless to languages as history was merciless to some people, even whole nations. Programming languages and developers get born, live and die leaving more or less tracks and successors, and not always the best survives. The history of programming languages is closely connected to the history of computers and computer science itself. Every single thing from one of them has its reflexions onto the other. This paper gives a short overview of last fifty years of computer programming and computer programming languages, but also gives many ideas that influenced other aspects of computer science. Particularly, programming paradigms are described, their

  9. Analysis of Higher Order Channel Dropping Tunneling Processes in Photonic Crystals

    Institute of Scientific and Technical Information of China (English)

    FU Jian; HE Sai-Ling

    2000-01-01

    A theoretical analysis is given for a higher order channel drop tunneling structure composed of two horizontal channels and a resonator system with two vertical multi-mode cavities in a two- or three-dimensional photonic crystal. Criteria for a complete transfer are derived for the application of wavelength division multiplexing. Compared to the resonator system with two single-mode cavities or a single multi-mode cavity, the present resonator system improves the transport properties.

  10. Initial Semantics for higher-order typed syntax in Coq

    Directory of Open Access Journals (Sweden)

    Benedikt Ahrens

    2011-01-01

    Full Text Available Initial Semantics aims at characterizing the syntax associated to a signature as the initial object of some category. We present an initial semantics result for typed higher-order syntax together with its formalization in the Coq proof assistant. The main theorem was first proved on paper in the second author’s PhD thesis in 2010, and verified formally shortly afterwards.To a simply–typed binding signature S over a fixed set T of object types we associate a category called the category of representations of S. We show that this category has an initial object Sigma(S, i.e. an object Sigma(S from which there is precisely one morphism i_R : Sigma(S -> R to any object R of this category. From its construction it will be clear that the object Sigma(S merits the name abstract syntax associated to S: it is given by an inductive set – parametrized by a set of free variables and dependent on object types – the type of whose constructors are each given by the arities of the signature S.Our theorem is implemented and proved correct in the proof assistant Coq through heavy use of dependent types. The approach through monads gives rise to an implementation of syntax where both terms and variables are intrinsically typed, i.e. where the object types are rejected in the meta–level types. Terms are implemented as a Coq data type – which play the role of sets – dependent on an object type as well as on a type family of free variables.This article is to be seen as a research article rather than about the formalization of a classical mathematical result. The nature of our theorem – involving lengthy, technical proofs and complicated algebraic structures – makes it particularly interesting for formal verification. Our goal is to promote the use of computer theorem provers as research tools, and, accordingly, a new way of publishing mathematical results: a parallel description of a theorem and its formalization should allow the verification of

  11. Analysis of wheezes using wavelet higher order spectral features.

    Science.gov (United States)

    Taplidou, Styliani A; Hadjileontiadis, Leontios J

    2010-07-01

    . This paves the way for the use of the wavelet higher order spectral features as an input vector to an efficient classifier. Apparently, this would integrate the intrinsic characteristics of wheezes within computerized diagnostic tools toward their more efficient evaluation.

  12. Signal Processing and Sampling Method for Obtaining Time Series Corresponding to Higher Order Derivatives

    Directory of Open Access Journals (Sweden)

    Andreea Sterian

    2010-01-01

    accuracy some significant quantities corresponding to the dynamic system. For fast phenomena, such significant quantities are represented by the derivatives of the received signals. In case of advanced computer modeling, the received signal should be filtered and converted into a time series corresponding to the estimated values for the dynamic system through a sampling procedure. This paper will show that present-day methods for computing in a robust manner the first derivative of a received signal (using an oscillating system working on a limited time interval and a supplementary differentiation method can be extended to the robust computation of higher order derivatives of the received signal by using a specific set of second-order oscillating systems (working also on limited time intervals so as estimative values for higher-order derivatives are to be directly generated (avoiding the necessity of additional differentiation or amplifying procedures, which represent a source of supplementary errors in present-day methods.

  13. Impedance Eduction in Large Ducts Containing Higher-Order Modes and Grazing Flow

    Science.gov (United States)

    Watson, Willie R.; Jones, Michael G.

    2017-01-01

    Impedance eduction test data are acquired in ducts with small and large cross-sectional areas at the NASA Langley Research Center. An improved data acquisition system in the large duct has resulted in increased control of the acoustic energy in source modes and more accurate resolution of higher-order duct modes compared to previous tests. Two impedance eduction methods that take advantage of the improved data acquisition to educe the liner impedance in grazing flow are presented. One method measures the axial propagation constant of a dominant mode in the liner test section (by implementing the Kumarsean and Tufts algorithm) and educes the impedance from an exact analytical expression. The second method solves numerically the convected Helmholtz equation and minimizes an objective function to obtain the liner impedance. The two methods are tested first on data synthesized from an exact mode solution and then on measured data. Results show that when the methods are applied to data acquired in the larger duct with a dominant higher-order mode, the same impedance spectra are educed as that obtained in the small duct where only the plane wave mode propagates. This result holds for each higher-order mode in the large duct provided that the higher-order mode is sufficiently attenuated by the liner.

  14. Numerical solving for nonlinear using higher order homotopy Taylor-perturbation

    Directory of Open Access Journals (Sweden)

    Nor Hanim Abd Rahman

    2013-03-01

    Full Text Available Rootfinding is a classical problem that still remains an interest to many researchers. A series of hybrid methods called Higher Order Homotopy Taylor-perturbation method via start-system functions (HTTPss are implemented to give approximate solutions for nonlinear equations, . The techniques serve as alternative methods for obtaining approximate solutions for different types of nonlinear equations. Thus, this paper presents an analysis on numerical comparison between the classical Newton Raphson (CNR, Homotopy Perturbation method (HTPss and Higher Order Homotopy Taylor-perturbation via start-system (HHTPss. A computational system Maple14 is used for this paper. Numerical and Illustrative results reveal that HHTPss methods are acceptably accurate and applicable.

  15. Values Education through Aggadic Stories: The Didactic Rewriter as Interpreter

    Science.gov (United States)

    Weinstein, Sara

    2016-01-01

    Didactic rewrites of aggadic stories are an important resource in values education. This study, geared primarily toward teachers involved in choosing curricular materials, investigates how the didactic rewriter actually becomes an interpreter, rather than a mere transmitter, of the original text. The personal values of the rewriters can influence…

  16. Values Education through Aggadic Stories: The Didactic Rewriter as Interpreter

    Science.gov (United States)

    Weinstein, Sara

    2016-01-01

    Didactic rewrites of aggadic stories are an important resource in values education. This study, geared primarily toward teachers involved in choosing curricular materials, investigates how the didactic rewriter actually becomes an interpreter, rather than a mere transmitter, of the original text. The personal values of the rewriters can influence…

  17. The period functionsʼ higher order derivatives

    Science.gov (United States)

    Sabatini, M.

    We prove a formula for the n-th derivative of the period function T in a period annulus of a planar differential system. For n=1, we obtain Freire, Gasull and Guillamon formula for the period's first derivative (Chicone and Dumortier, 1993) [17]. We apply such a result to Hamiltonian systems with separable variables and other systems. We give some sufficient conditions for the period function of conservative second order ODE's to be convex.

  18. Flipping & Clicking Your Way to Higher-Order Learning

    Science.gov (United States)

    Garver, Michael S.; Roberts, Brian A.

    2013-01-01

    This innovative system of teaching and learning includes the implementation of two effective learning technologies: podcasting ("flipping") and classroom response systems ("clicking"). Students watch lectures in podcast format before coming to class, which allows the "entire" class period to be devoted to active…

  19. Practical Programming with Higher-Order Encodings and Dependent Types

    DEFF Research Database (Denmark)

    Poswolsky, Adam; Schürmann, Carsten

    2008-01-01

    utilizing HOAS free the programmer from concerns of handling explicit contexts and substitutions, our system permits programming over such encodings without making these constructs explicit, leading to concise and elegant programs. To this end our system distinguishes bindings of variables intended...

  20. Analytical On-shell Calculation of Higher Order Scattering: Massive Particles

    CERN Document Server

    Holstein, Barry R

    2016-01-01

    We demonstrate that the use of on-shell methods, involving calculation of the discontinuity across the t-channel cut associated with the exchange of a pair of massless particles, can be used to evaluate loop contributions to both the electromagnetic and gravitational scattering of massive systems. In the gravitational case, the use of factorization permits a straightforward and algebraic calculation of higher order scattering results, which were obtained previously by much more arduous Feynman diagram techniques.

  1. Multiple Iterative Splitting method for Higher order and Integro-differental equations

    CERN Document Server

    Geiser, Juergen

    2012-01-01

    In this paper we present an extension of standard iterative splitting schemes to multiple splitting schemes for solving higher order differential equations. We are motivated by dynamical systems, which occur in dynamics of the electrons in the plasma using a simplified Boltzmann equation. Oscillation problems in spectroscopy problems using wave-equations. The motivation arose to simulate active plasma resonance spectroscopy which is used for plasma diagnostic techniques.

  2. Parallel Execution of Multi Set Constraint Rewrite Rules

    DEFF Research Database (Denmark)

    Sulzmann, Martin; Lam, Edmund Soon Lee

    2008-01-01

    that the underlying constraint rewrite implementation executes rewrite steps in parallel on increasingly popular becoming multi-core architectures. We design and implement efficient algorithms which allow for the parallel execution of multi-set constraint rewrite rules. Our experiments show that we obtain some......Multi-set constraint rewriting allows for a highly parallel computational model and has been used in a multitude of application domains such as constraint solving, agent specification etc. Rewriting steps can be applied simultaneously as long as they do not interfere with each other.We wish...

  3. Mark formation model for optical rewritable recording

    NARCIS (Netherlands)

    Brusche, J.H.

    2007-01-01

    Optically rewritable discs contain one or more so-called recording stacks. These stacks consist of various grooved layers. At least one of these layers contains a so-called phase-change material. In the recording layer, amorphous regions are formed on a crystalline background by means of high power

  4. On Comparison of Rewriting and skopostheory

    Institute of Scientific and Technical Information of China (English)

    雷鸣

    2015-01-01

    Andrew Lefevere and Hans Vermeer’ are outstanding figures in the history of translation studies.Their theory Rewriting and Skopostheory can be considered as milestone in their study history.This paper makes comparison between two theories with regard to their main features and makes persons-in-the-translation further get a deeper understanding of two theories.

  5. Mark formation modeling in optical rewritable recording

    NARCIS (Netherlands)

    Brusche, J.H.; Segal, A.; Vuik, C.; Urbach, H.P.

    2006-01-01

    In optical rewritable recording media, such as the Blu-ray Disc, amorphous marks are formed on a crystalline background of a phase-change layer, by means of short, high power laser pulses. In order to improve this data storage concept, it is of great importance to understand the mark formation

  6. Mark formation modeling in optical rewritable recording

    NARCIS (Netherlands)

    Brusche, J.H.; Segal, A.; Vuik, C.; Urbach, H.P.

    2006-01-01

    In optical rewritable recording media, such as the Blu-ray Disc, amorphous marks are formed on a crystalline background of a phase-change layer, by means of short, high power laser pulses. In order to improve this data storage concept, it is of great importance to understand the mark formation proce

  7. Generalized quantum kinetic expansion: Higher-order corrections to multichromophoric Förster theory.

    Science.gov (United States)

    Wu, Jianlan; Gong, Zhihao; Tang, Zhoufei

    2015-08-21

    For a general two-cluster energy transfer network, a new methodology of the generalized quantum kinetic expansion (GQKE) method is developed, which predicts an exact time-convolution equation for the cluster population evolution under the initial condition of the local cluster equilibrium state. The cluster-to-cluster rate kernel is expanded over the inter-cluster couplings. The lowest second-order GQKE rate recovers the multichromophoric Förster theory (MCFT) rate. The higher-order corrections to the MCFT rate are systematically included using the continued fraction resummation form, resulting in the resummed GQKE method. The reliability of the GQKE methodology is verified in two model systems, revealing the relevance of higher-order corrections.

  8. Higher-order numerical methods derived from three-point polynomial interpolation

    Science.gov (United States)

    Rubin, S. G.; Khosla, P. K.

    1976-01-01

    Higher-order collocation procedures resulting in tridiagonal matrix systems are derived from polynomial spline interpolation and Hermitian finite-difference discretization. The equations generally apply for both uniform and variable meshes. Hybrid schemes resulting from different polynomial approximations for first and second derivatives lead to the nonuniform mesh extension of the so-called compact or Pade difference techniques. A variety of fourth-order methods are described and this concept is extended to sixth-order. Solutions with these procedures are presented for the similar and non-similar boundary layer equations with and without mass transfer, the Burgers equation, and the incompressible viscous flow in a driven cavity. Finally, the interpolation procedure is used to derive higher-order temporal integration schemes and results are shown for the diffusion equation.

  9. Space-demultiplexing based on higher-order Poincaré spheres.

    Science.gov (United States)

    Fernandes, Gil M; Muga, Nelson J; Pinto, Armando N

    2017-02-20

    We propose a space-demultiplexing algorithm based on signal analysis in higher-order Poincaré spheres for optical transmission systems supported by space-division multiplexing. This algorithm is modulation format agnostic and does not require training sequences. We show that any arbitrary pair of tributaries signals can be represented in a higher-order Poincaré sphere. In such sphere, the crosstalk between any two tributary signals can be reversed by computing and realigning the best fit plane. Using this procedure for all possible combinations of tributaries the transmitted signal is successfully recovered, with negligible signal-to-noise ratio (SNR) penalties for quadrature phase-shift keying (QPSK) and 16-quadrature amplitude modulation (QAM) constellations, and with a SNR penalty as lower as 0.5 dB for the 64-QAM.

  10. Benchmark experiments for higher-order and full-Stokes ice sheet models (ISMIP–HOM

    Directory of Open Access Journals (Sweden)

    F. Pattyn

    2008-08-01

    Full Text Available We present the results of the first ice sheet model intercomparison project for higher-order and full-Stokes ice sheet models. These models are compared and verified in a series of six experiments of which one has an analytical solution obtained from a perturbation analysis. The experiments are applied to both 2-D and 3-D geometries; five experiments are steady-state diagnostic, and one has a time-dependent prognostic solution. All participating models give results that are in close agreement. A clear distinction can be made between higher-order models and those that solve the full system of equations. The full-Stokes models show a much smaller spread, hence are in better agreement with one another and with the analytical solution.

  11. Benchmark experiments for higher-order and full Stokes ice sheet models (ISMIP-HOM

    Directory of Open Access Journals (Sweden)

    F. Pattyn

    2008-02-01

    Full Text Available We present the results of the first ice sheet model intercomparison project for higher-order and full Stokes ice sheet models. These models are validated in a series of six benchmark experiments of which one has an analytical solution under simplifying assumptions. Five of the tests are diagnostic and one experiment is prognostic or time dependent, for both 2-D and 3-D geometries. The results show a good convergence of the different models even for high aspect ratios. A clear distinction can be made between higher-order models and those that solve the full system of equations. The latter show a significantly better agreement with each other as well as with analytical solutions, which demonstrates that they are hardly influenced by the used numerics.

  12. Higher-Order Structure in Bacterial VapBC Toxin-Antitoxin Complexes

    DEFF Research Database (Denmark)

    Bendtsen, Kirstine L; Brodersen, Ditlev E

    2017-01-01

    Toxin-antitoxin systems are widespread in the bacterial kingdom, including in pathogenic species, where they allow rapid adaptation to changing environmental conditions through selective inhibition of key cellular processes, such as DNA replication or protein translation. Under normal growth...... conditions, type II toxins are inhibited through tight protein-protein interaction with a cognate antitoxin protein. This toxin-antitoxin complex associates into a higher-order macromolecular structure, typically heterotetrameric or heterooctameric, exposing two DNA binding domains on the antitoxin...... that allow auto-regulation of transcription by direct binding to promoter DNA. In this chapter, we review our current understanding of the structural characteristics of type II toxin-antitoxin complexes in bacterial cells, with a special emphasis on the staggering variety of higher-order architecture...

  13. Response spectrum method for extreme wave loading with higher order components of drag force

    Science.gov (United States)

    Reza, Tabeshpour Mohammad; Mani, Fatemi Dezfouli; Mohammad Ali, Dastan Diznab; Saied, Mohajernasab; Saied, Seif Mohammad

    2017-01-01

    Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass attached to a light cantilever cylinder and their corresponding deformation response spectra are estimated by utilizing a generalized single degree of freedom system. Based on the wave data recorded in the Persian Gulf region, extreme wave loading conditions corresponding to different return periods are exerted on the offshore structures. Accordingly, the effect of the higher order components of the drag force is considered and compared to the linearized state for different sea surface levels. When the fundamental period of the offshore structure is about one third of the main period of wave loading, the results indicate the linearized drag term is not capable of achieving a reliable deformation response spectrum.

  14. Recurrent activity in higher order, modality non-specific brain regions

    DEFF Research Database (Denmark)

    Lou, Hans Olav Christensen; Joensson, Morten; Biermann-Ruben, Katja

    2011-01-01

    in the visual system as a response to visual stimulation. In contrast recurrent activity has never been demonstrated before in higher order modality non-specific regions. Using magneto-encephalography and Granger causality analysis, we tested in a paralimbic network the hypothesis that stimulation may enhance...... causal recurrent interaction between higher-order, modality non-specific regions. The network includes anterior cingulate/medial prefrontal and posterior cingulate/medial parietal cortices together with pulvinar thalami, a network known to be effective in autobiographic memory retrieval and self......-awareness. Autobiographic memory retrieval of previous personal judgments of visually presented words was used as stimuli. It is demonstrated that the prestimulus condition is characterized by causal, recurrent oscillations which are maximal in the lower gamma range. When retrieving previous judgments of visually presented...

  15. Higher-order transformation and the distributed data problem.

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Victor Lono (University of Nebraska at Omaha, Omaha, NE); Subramaniam, Mahadevan (University of Nebraska at Omaha, Omaha, NE)

    2003-12-01

    The distributed data problem, is characterized by the desire to bring together semantically related data from syntactically unrelated portions of a term. Two strategic combinators, dynamic and transient, are introduced in the context of a classical strategic programming framework. The impact of the resulting system on instances of the distributed data problem is then explored.

  16. Modeling Human Behaviour with Higher Order Logic: Insider Threats

    NARCIS (Netherlands)

    Boender, Jaap; Ivanova, Marieta Georgieva; Kammüller, Florian; Primierio, Giuseppe

    2014-01-01

    In this paper, we approach the problem of modeling the human component in technical systems with a view on the difference between the use of model and theory in sociology and computer science. One aim of this essay is to show that building of theories and models for sociology can be compared and imp

  17. Higher-Order and Symbolic Computation. LISP and Symbolic Computationditorial

    DEFF Research Database (Denmark)

    Danvy, Olivier; Dybvig, R. Kent; Lawall, Julia

    2008-01-01

    system for these static checks and a corresponding type-inference algorithm. In "An Investigation of Jones Optimality and BTI-Universal Specializers," Robert Glueck establishes a connection between Jones optimal-program specializers and binding-time improvers. This article completes a study started...

  18. Quantum Noether identities for non-local transformations in higher-order derivatives theories

    CERN Document Server

    Li, Z P

    2003-01-01

    Based on the phase-space generating functional of the Green function for a system with a regular/singular higher-order Lagrangian, the quantum canonical Noether identities (NIs) under a local and non-local transformation in phase space have been deduced, respectively. For a singular higher-order Lagrangian, one must use an effective canonical action I sub e sub f sub f sup P in quantum canonical NIs instead of the classical I sup P in classical canonical NIs. The quantum NIs under a local and non-local transformation in configuration space for a gauge-invariant system with a higher-order Lagrangian have also been derived. The above results hold true whether or not the Jacobian of the transformation is equal to unity or not. It has been pointed out that in certain cases the quantum NIs may be converted to conservation laws at the quantum level. This algorithm to derive the quantum conservation laws is significantly different from the quantum first Noether theorem. The applications of our formulation to the Yan...

  19. Higher-order neural network software for distortion invariant object recognition

    Science.gov (United States)

    Reid, Max B.; Spirkovska, Lilly

    1991-01-01

    The state-of-the-art in pattern recognition for such applications as automatic target recognition and industrial robotic vision relies on digital image processing. We present a higher-order neural network model and software which performs the complete feature extraction-pattern classification paradigm required for automatic pattern recognition. Using a third-order neural network, we demonstrate complete, 100 percent accurate invariance to distortions of scale, position, and in-plate rotation. In a higher-order neural network, feature extraction is built into the network, and does not have to be learned. Only the relatively simple classification step must be learned. This is key to achieving very rapid training. The training set is much smaller than with standard neural network software because the higher-order network only has to be shown one view of each object to be learned, not every possible view. The software and graphical user interface run on any Sun workstation. Results of the use of the neural software in autonomous robotic vision systems are presented. Such a system could have extensive application in robotic manufacturing.

  20. Higher-order adaptive finite-element methods for Kohn–Sham density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Motamarri, P. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Nowak, M.R. [Department of Electrical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Leiter, K.; Knap, J. [U.S. Army Research Labs, Aberdeen Proving Ground, Aberdeen, MD 21001 (United States); Gavini, V., E-mail: vikramg@umich.edu [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

    2013-11-15

    We present an efficient computational approach to perform real-space electronic structure calculations using an adaptive higher-order finite-element discretization of Kohn–Sham density-functional theory (DFT). To this end, we develop an a priori mesh-adaption technique to construct a close to optimal finite-element discretization of the problem. We further propose an efficient solution strategy for solving the discrete eigenvalue problem by using spectral finite-elements in conjunction with Gauss–Lobatto quadrature, and a Chebyshev acceleration technique for computing the occupied eigenspace. The proposed approach has been observed to provide a staggering 100–200-fold computational advantage over the solution of a generalized eigenvalue problem. Using the proposed solution procedure, we investigate the computational efficiency afforded by higher-order finite-element discretizations of the Kohn–Sham DFT problem. Our studies suggest that staggering computational savings—of the order of 1000-fold—relative to linear finite-elements can be realized, for both all-electron and local pseudopotential calculations, by using higher-order finite-element discretizations. On all the benchmark systems studied, we observe diminishing returns in computational savings beyond the sixth-order for accuracies commensurate with chemical accuracy, suggesting that the hexic spectral-element may be an optimal choice for the finite-element discretization of the Kohn–Sham DFT problem. A comparative study of the computational efficiency of the proposed higher-order finite-element discretizations suggests that the performance of finite-element basis is competing with the plane-wave discretization for non-periodic local pseudopotential calculations, and compares to the Gaussian basis for all-electron calculations to within an order of magnitude. Further, we demonstrate the capability of the proposed approach to compute the electronic structure of a metallic system containing 1688

  1. Passivity analysis of higher order evolutionary dynamics and population games

    KAUST Repository

    Mabrok, Mohamed

    2017-01-05

    Evolutionary dynamics describe how the population composition changes in response to the fitness levels, resulting in a closed-loop feedback system. Recent work established a connection between passivity theory and certain classes of population games, namely so-called “stable games”. In particular, it was shown that a combination of stable games and (an analogue of) passive evolutionary dynamics results in stable convergence to Nash equilibrium. This paper considers the converse question of necessary conditions for evolutionary dynamics to exhibit stable behaviors for all generalized stable games. Using methods from robust control analysis, we show that if an evolutionary dynamic does not satisfy a passivity property, then it is possible to construct a generalized stable game that results in instability. The results are illustrated on selected evolutionary dynamics with particular attention to replicator dynamics, which are also shown to be lossless, a special class of passive systems.

  2. Higher-order perturbative relativistic corrections to energies and properties

    OpenAIRE

    Stopkowicz, Stella

    2011-01-01

    Relativistic effects need to be considered in quantum-chemical calculations on systems including heavy elements or when aiming at high accuracy for molecules containing only lighter elements. In the latter case, consideration of relativistic effects via perturbation theory is an attractive option. Among the available techniques, Direct Perturbation Theory (DPT) in its lowest order (DPT2) has become a standard tool for the calculation of relativistic corrections to energies and properties.In t...

  3. A family of solutions of a higher order PVI equation near a regular singularity

    Science.gov (United States)

    Shimomura, Shun

    2006-09-01

    Restriction of the N-dimensional Garnier system to a complex line yields a system of second-order nonlinear differential equations, which may be regarded as a higher order version of the sixth Painlevé equation. Near a regular singularity of the system, we present a 2N-parameter family of solutions expanded into convergent series. These solutions are constructed by iteration, and their convergence is proved by using a kind of majorant series. For simplicity, we describe the proof in the case N = 2.

  4. The role of short answer questions in developing higher-order thinking

    Directory of Open Access Journals (Sweden)

    Stella Grenville

    2011-08-01

    Full Text Available The  Humanities Faculty at the University of the Witwatersrand has introduced a number of one-year foundation courses to provide support to students and to enable those from a disadvantaged educational system to enter the academic environment.  The focus in this paper is on the role of short answer questions in the assessment of higher order thinking.  Short answer questions have traditionally been thought to assess factual recall and lower levels of response. We argue that short answer questions have the potential to assess a range of competencies including higher order thinking.  We argue that short answer questions help to support student learning of disciplinary concepts and skills by breaking down and sequencing final summative assessment tasks into smaller manageable tasks.  We examine the relationship between higher order thinking and modes of assessment, and develop a taxonomy to show the relationship between task words and levels of intellectual performance. This may be used to align course assessment with learning outcomes and teaching practices.

  5. Transition, coexistence, and interaction of vector localized waves arising from higher-order effects

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chong [School of Physics, Northwest University, Xi’an 710069 (China); Yang, Zhan-Ying, E-mail: zyyang@nwu.edu.cn [School of Physics, Northwest University, Xi’an 710069 (China); Zhao, Li-Chen, E-mail: zhaolichen3@163.com [School of Physics, Northwest University, Xi’an 710069 (China); Yang, Wen-Li [Institute of Modern Physics, Northwest University, Xi’an 710069 (China)

    2015-11-15

    We study vector localized waves on continuous wave background with higher-order effects in a two-mode optical fiber. The striking properties of transition, coexistence, and interaction of these localized waves arising from higher-order effects are revealed in combination with corresponding modulation instability (MI) characteristics. It shows that these vector localized wave properties have no analogues in the case without higher-order effects. Specifically, compared to the scalar case, an intriguing transition between bright–dark rogue waves and w-shaped–anti-w-shaped solitons, which occurs as a result of the attenuation of MI growth rate to vanishing in the zero-frequency perturbation region, is exhibited with the relative background frequency. In particular, our results show that the w-shaped–anti-w-shaped solitons can coexist with breathers, coinciding with the MI analysis where the coexistence condition is a mixture of a modulation stability and MI region. It is interesting that their interaction is inelastic and describes a fusion process. In addition, we demonstrate an annihilation phenomenon for the interaction of two w-shaped solitons which is identified essentially as an inelastic collision in this system. -- Highlights: •Vector rogue wave properties induced by higher-order effects are studied. •A transition between vector rogue waves and solitons is obtained. •The link between the transition and modulation instability (MI) is demonstrated. •The coexistence of vector solitons and breathers coincides with the MI features. •An annihilation phenomenon for the vector two w-shaped solitons is presented.

  6. Higher-order auditory areas in congenital deafness: Top-down interactions and corticocortical decoupling.

    Science.gov (United States)

    Kral, Andrej; Yusuf, Prasandhya A; Land, Rüdiger

    2017-01-01

    The theory of predictive coding assumes that higher-order representations influence lower-order representations by generating predictions about sensory input. In congenital deafness, one identified dysfunction is a reduced activation of deep layers in the auditory cortex. Since these layers play a central role for processing top-down influences, congenital deafness might interfere with the integration of top-down and bottom-up information flow. Studies in humans suggest more deficits in higher-order than in primary cortical areas in congenital deafness. That opens up the question how well neurons in higher-order areas can be activated by the input through the deprived auditory pathway after restoration of hearing with cochlear implants. Further it is unclear whether their interconnections to lower order areas are impaired by absence of hearing. Corticocortical anatomical fiber tracts and general auditory responsiveness in both primary and higher-order areas are generally preserved in absence of auditory experience. However, the existing data suggest a dichotomy between preservation of anatomical cortical connectivity in congenital deafness and functional deficits in corticocortical coupling. Further, cross-modal reorganization observed in congenital deafness in specific cortical areas appears to be established by functional synaptic changes and rests on anatomically preserved, genetically-predetermined and molecularly patterned circuitry connecting the sensory systems. Current data indicate a reduced corticocortical functional coupling between cortical auditory areas in congenital deafness, both in bottom-up and top-down information stream. Consequently, congenital deafness is likely to result in a deficit in predictive coding that affects learning ability after late cochlear implantation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Simulations of higher order modes simulations of higher order modes in the ACC39 module of FLASH

    CERN Document Server

    Shinton, I R R; Li, Z; Zhang, P

    2012-01-01

    This study is focused on the development of a HOM-based BPM system for the ACC39 module currently installed and in operation at FLASH. A similar system is anticipated to be installed at XFEL. Coupled inter-cavity modes are simulated together with a limited band of trapped modes. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities with a view to providing guidance on their use as a cavity beam diagnostic.

  8. Lazy AC-Pattern Matching for Rewriting

    OpenAIRE

    Walid Belkhir; Alain Giorgetti

    2012-01-01

    We define a lazy pattern-matching mechanism modulo associativity and commutativity. The solutions of a pattern-matching problem are stored in a lazy list composed of a first substitution at the head and a non-evaluated object that encodes the remaining computations. We integrate the lazy AC-matching in a strategy language: rewriting rule and strategy application produce a lazy list of terms.

  9. Lazy AC-Pattern Matching for Rewriting

    Directory of Open Access Journals (Sweden)

    Walid Belkhir

    2012-04-01

    Full Text Available We define a lazy pattern-matching mechanism modulo associativity and commutativity. The solutions of a pattern-matching problem are stored in a lazy list composed of a first substitution at the head and a non-evaluated object that encodes the remaining computations. We integrate the lazy AC-matching in a strategy language: rewriting rule and strategy application produce a lazy list of terms.

  10. On the Identities of Symmetry for the -Euler Polynomials of Higher Order

    Directory of Open Access Journals (Sweden)

    Park KyoungHo

    2009-01-01

    Full Text Available The main purpose of this paper is to investigate several further interesting properties of symmetry for the multivariate -adic fermionic integral on . From these symmetries, we can derive some recurrence identities for the -Euler polynomials of higher order, which are closely related to the Frobenius-Euler polynomials of higher order. By using our identities of symmetry for the -Euler polynomials of higher order, we can obtain many identities related to the Frobenius-Euler polynomials of higher order.

  11. Generation of higher order Gauss-Laguerre modes in single-pass 2nd harmonic generation

    DEFF Research Database (Denmark)

    Buchhave, Preben; Tidemand-Lichtenberg, Peter

    2008-01-01

    We present a realistic method for dynamic simulation of the development of higher order modes in second harmonic generation. The deformation of the wave fronts due to the nonlinear interaction is expressed by expansion in higher order Gauss-Laguerre modes.......We present a realistic method for dynamic simulation of the development of higher order modes in second harmonic generation. The deformation of the wave fronts due to the nonlinear interaction is expressed by expansion in higher order Gauss-Laguerre modes....

  12. Modular specification and verification for higher-order languages with state

    DEFF Research Database (Denmark)

    Svendsen, Kasper

    dependent type theory with effects. The motivation is to take advantage of an existing implementation of a pure dependent type theory to obtain an implementation of a formal proof system based on higher-order separation logic. In particular, we extend the Calculus of Inductive Constructions with monadically...... encapsulated stateful and potentially non-terminating computations. The monadic computation types are indexed with pre- and postconditions and act as partial correctness specifications. The type theory supports local reasoning about state through a notion of disjointness strongly inspired by separation logic....

  13. Higher-order schemes for the Laplace transformation method for parabolic problems

    KAUST Repository

    Douglas, C.

    2011-01-01

    In this paper we solve linear parabolic problems using the three stage noble algorithms. First, the time discretization is approximated using the Laplace transformation method, which is both parallel in time (and can be in space, too) and extremely high order convergent. Second, higher-order compact schemes of order four and six are used for the the spatial discretization. Finally, the discretized linear algebraic systems are solved using multigrid to show the actual convergence rate for numerical examples, which are compared to other numerical solution methods. © 2011 Springer-Verlag.

  14. Algebraic Specifications, Higher-order Types and Set-theoretic Models

    DEFF Research Database (Denmark)

    Kirchner, Hélène; Mosses, Peter David

    2001-01-01

    In most algebraic  specification frameworks, the type system is restricted to sorts, subsorts, and first-order function types. This is in marked contrast to the so-called model-oriented frameworks, which provide higer-order types, interpreted set-theoretically as Cartesian products, function spaces......, and power-sets. This paper presents a simple framework for algebraic specifications with higher-order types and set-theoretic models. It may be regarded as the basis for a Horn-clause approximation to the Z framework, and has the advantage of being amenable to prototyping and automated reasoning. Standard...

  15. Travelling wave solutions for higher-order wave equations of kdv type (iii).

    Science.gov (United States)

    Li, Jibin; Rui, Weigou; Long, Yao; He, Bin

    2006-01-01

    By using the theory of planar dynamical systems to the travelling wave equation of a higher order nonlinear wave equations of KdV type, the existence of smooth solitary wave, kink wave and anti-kink wave solutions and uncountably infinite many smooth and non-smooth periodic wave solutions are proved. In different regions of the parametric space, the sufficient conditions to guarantee the existence of the above solutions are given. In some conditions, exact explicit parametric representations of these waves are obtain.

  16. Higher order modes HOMs in coupled cavities of the FLASH module ACC39

    CERN Document Server

    Shinton, I R R; Li, Z; Zhang, P

    2011-01-01

    We analyse the higher order modes (HOM’s) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.

  17. Dynamic bifurcation of a modified Kuramoto-Sivashinsky equation with higher-order nonlinearity

    Institute of Scientific and Technical Information of China (English)

    Huang Qiong-Wei; Tang Jia-Shi

    2011-01-01

    Under the periodic boundary condition,dynamic bifurcation and stability in the modified Kuramoto-Sivashinsky equation with a higher-order nonlinearity p(ux)Puxx are investigated by using the centre manifold reduction procedure.The result shows that as the control parameter crosses a critical value,the system undergoes a bifurcation from the trivial solution to produce a cycle consisting of locally asymptotically stable equilibrium points. Furthermore,for cases in which the distances to the bifurcation points are small enough,one-order approximations to the bifurcation solutions are obtained.

  18. Higher Order Modes in Coupled Cavities of the Flash Module ACC39

    CERN Document Server

    Shinton, I R R; Li, Z; Zhang, P

    2011-01-01

    We analyse the higher order modes (HOM's) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.

  19. Quantum Effects in Higher-Order Correlators of a Quantum-Dot Spin Qubit

    Science.gov (United States)

    Bechtold, A.; Li, F.; Müller, K.; Simmet, T.; Ardelt, P.-L.; Finley, J. J.; Sinitsyn, N. A.

    2016-07-01

    We measure time correlators of a spin qubit in an optically active quantum dot beyond the second order. Such higher-order correlators are shown to be directly sensitive to pure quantum effects that cannot be explained within the classical framework. They allow direct determination of ensemble and quantum dephasing times, T2* and T2, using only repeated projective measurements and without the need for coherent spin control. Our method enables studies of purely quantum behavior in solid state systems, including tests of the Leggett-Garg type of inequalities that rule out local hidden variable interpretation of the quantum-dot spin dynamics.

  20. Higher-order multi-resolution topology optimization using the finite cell method

    DEFF Research Database (Denmark)

    Groen, Jeroen Peter; Langelaar, Matthijs; Sigmund, Ole

    2017-01-01

    This article presents a detailed study on the potential and limitations of performing higher-order multi-resolution topology optimization with the finite cell method. To circumvent stiffness overestimation in high-contrast topologies, a length-scale is applied on the solution using filter methods....... The relations between stiffness overestimation, the analysis system, and the applied length-scale are examined, while a high-resolution topology is maintained. The computational cost associated with nested topology optimization is reduced significantly compared with the use of first-order finite elements...

  1. A Higher Order Analysis of the Factor Structure of the Myers-Briggs Type Indicator.

    Science.gov (United States)

    Johnson, William L.; Mauzey, Edward; Johnson, Annabel M.; Murphy, Stanley D.; Zimmerman, Kurt J.

    2001-01-01

    Examines the higher order structure of Form G of the Myers Briggs Type Indicator. A third order component analysis of a sample (N=926) found two higher order components. This higher order analysis contributes to the research literature pertaining to the generalized structure of the personality measure. (Contains 44 references and 1 table.) (GCP)

  2. On the expressiveness and decidability of higher-order process calculi

    NARCIS (Netherlands)

    Lanese, Ivan; Perez, Jorge A.; Sangiorgi, Davide; Schmitt, Alan

    2011-01-01

    In higher-order process calculi, the values exchanged in communications may contain processes. A core calculus of higher-order concurrency is studied; it has only the operators necessary to express higher-order communications: input prefix, process output, and parallel composition. By exhibiting a d

  3. Higher order hierarchical discretization scheme for surface integral equations for layered media

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Kim, Oleksiy S.; Meincke, Peter;

    2004-01-01

    equation. This higher order MoM solution comprises higher order curved patches for the geometry modeling and higher order hierarchical basis functions for expansion of the electric surface current density. Due to the hierarchical property of the basis functions, the order of the expansion can be selected...

  4. A Higher Order Analysis of the Factor Structure of the Myers-Briggs Type Indicator.

    Science.gov (United States)

    Johnson, William L.; Mauzey, Edward; Johnson, Annabel M.; Murphy, Stanley D.; Zimmerman, Kurt J.

    2001-01-01

    Examines the higher order structure of Form G of the Myers Briggs Type Indicator. A third order component analysis of a sample (N=926) found two higher order components. This higher order analysis contributes to the research literature pertaining to the generalized structure of the personality measure. (Contains 44 references and 1 table.) (GCP)

  5. Rewritable 3D bit optical data storage in a PMMA-based photorefractive polymer

    Energy Technology Data Exchange (ETDEWEB)

    Day, D.; Gu, M. [Swinburne Univ. of Tech., Hawthorn, Vic. (Australia). Centre for Micro-Photonics; Smallridge, A. [Victoria Univ., Melbourne (Australia). School of Life Sciences and Technology

    2001-07-04

    A cheap, compact, and rewritable high-density optical data storage system for CD and DVD applications is presented by the authors. Continuous-wave illumination under two-photon excitation in a new poly(methylmethacrylate) (PMMA) based photorefractive polymer allows 3D bit storage of sub-Tbyte data. (orig.)

  6. Improvements to local projective noise reduction through higher order and multiscale refinements

    Science.gov (United States)

    Moore, Jack Murdoch; Small, Michael; Karrech, Ali

    2015-06-01

    The broad spectrum characteristic of signals from nonlinear systems obstructs noise reduction techniques developed for linear systems. Local projection was developed to reduce noise while preserving nonlinear deterministic structures, and a second order refinement to local projection which was proposed ten years ago does so particularly effectively. It involves adjusting the origin of the projection subspace to better accommodate the geometry of the attractor. This paper describes an analytic motivation for the enhancement from which follows further higher order and multiple scale refinements. However, the established enhancement is frequently as or more effective than the new filters arising from solely geometric considerations. Investigation of the way that measurement errors reinforce or cancel throughout the refined local projection procedure explains the special efficacy of the existing enhancement, and leads to a new second order refinement offering widespread gains. Different local projective filters are found to be best suited to different noise levels. At low noise levels, the optimal order increases as noise increases. At intermediate levels second order tends to be optimal, while at high noise levels prototypical local projection is most effective. The new higher order filters perform better relative to established filters for longer signals or signals corresponding to higher dimensional attractors.

  7. Higher-order generalized hydrodynamics: Foundations within a nonequilibrium statistical ensemble formalism.

    Science.gov (United States)

    Silva, Carlos A B; Rodrigues, Clóves G; Ramos, J Galvão; Luzzi, Roberto

    2015-06-01

    Construction, in the framework of a nonequilibrium statistical ensemble formalism, of a higher-order generalized hydrodynamics, also referred to as mesoscopic hydrothermodynamics, that is, covering phenomena involving motion of fluids displaying variations short in space and fast in time-unrestricted values of Knudsen numbers, is presented. In that way, an approach is provided enabling the coupling and simultaneous treatment of the kinetics and hydrodynamic levels of descriptions. It is based on a complete thermostatistical approach in terms of the densities of matter and energy and their fluxes of all orders covering systems arbitrarily driven away from equilibrium. The set of coupled nonlinear integrodifferential hydrodynamic equations is derived. They are the evolution equations of the Gradlike moments of all orders, derived from a generalized kinetic equation built in the framework of the nonequilibrium statistical ensemble formalism. For illustration, the case of a system of particles embedded in a fluid acting as a thermal bath is fully described. The resulting enormous set of coupled evolution equations is of unmanageable proportions, thus requiring in practice to introduce an appropriate description using the smallest possible number of variables. We have obtained a hierarchy of Maxwell times, associated to the set of all the higher-order fluxes, which have a particular relevance in the process of providing criteria for establishing the contraction of description.

  8. 高阶布尔网络的结构%Structure of higher order Boolean networks*

    Institute of Scientific and Technical Information of China (English)

    李志强; 赵寅; 程代展

    2011-01-01

    The higher order Boolean (control) network is introduced and its topological structure is studied.Using semi-tensor product of matrices,its dynamics is converted into two algebraic forms,which are standard discrete-time dynamic systems.The one-to-one correspondence of the network dynamics and its first algebraic form is proved,and certain topological structures,including fixed points,cycles,and transient time,of higher order Boolean (control) networks are revealed.The relationship between the original system and its second algebraic form is also studied.%介绍高阶布尔(控制)网络,并研究了其拓扑结构.以矩阵的半张量积作为工具,把高阶布尔网络的动态过程转化为2种标准离散事件动态系统的代数形式.证明了高阶布尔网络和第1代数形式的一一对应关系,并由此得到其拓扑结构(不动点、极限圈以及暂态期等).还研究了高阶布尔网络系统与它第2代数形式的关系.

  9. Orbital period changes and the higher-order multiplicity fraction amongst SuperWASP eclipsing binaries

    CERN Document Server

    Lohr, M E; Payne, S G; West, R G; Wheatley, P J

    2015-01-01

    Orbital period changes of binary stars may be caused by the presence of a third massive body in the system. Here we have searched the archive of the Wide Angle Search for Planets (SuperWASP) project for evidence of period variations in 13927 eclipsing binary candidates. Sinusoidal period changes, strongly suggestive of third bodies, were detected in 2% of cases; however, linear period changes were observed in a further 22% of systems. We argue on distributional grounds that the majority of these apparently linear changes are likely to reflect longer-term sinusoidal period variations caused by third bodies, and thus estimate a higher-order multiplicity fraction of 24% for SuperWASP binaries, in good agreement with other recent figures for the fraction of triple systems amongst binary stars in general.

  10. Hotspot detection using image pattern recognition based on higher-order local auto-correlation

    Science.gov (United States)

    Maeda, Shimon; Matsunawa, Tetsuaki; Ogawa, Ryuji; Ichikawa, Hirotaka; Takahata, Kazuhiro; Miyairi, Masahiro; Kotani, Toshiya; Nojima, Shigeki; Tanaka, Satoshi; Nakagawa, Kei; Saito, Tamaki; Mimotogi, Shoji; Inoue, Soichi; Nosato, Hirokazu; Sakanashi, Hidenori; Kobayashi, Takumi; Murakawa, Masahiro; Higuchi, Tetsuya; Takahashi, Eiichi; Otsu, Nobuyuki

    2011-04-01

    Below 40nm design node, systematic variation due to lithography must be taken into consideration during the early stage of design. So far, litho-aware design using lithography simulation models has been widely applied to assure that designs are printed on silicon without any error. However, the lithography simulation approach is very time consuming, and under time-to-market pressure, repetitive redesign by this approach may result in the missing of the market window. This paper proposes a fast hotspot detection support method by flexible and intelligent vision system image pattern recognition based on Higher-Order Local Autocorrelation. Our method learns the geometrical properties of the given design data without any defects as normal patterns, and automatically detects the design patterns with hotspots from the test data as abnormal patterns. The Higher-Order Local Autocorrelation method can extract features from the graphic image of design pattern, and computational cost of the extraction is constant regardless of the number of design pattern polygons. This approach can reduce turnaround time (TAT) dramatically only on 1CPU, compared with the conventional simulation-based approach, and by distributed processing, this has proven to deliver linear scalability with each additional CPU.

  11. Higher-Order Structure in Bacterial VapBC Toxin-Antitoxin Complexes.

    Science.gov (United States)

    Bendtsen, Kirstine L; Brodersen, Ditlev E

    2017-01-01

    Toxin-antitoxin systems are widespread in the bacterial kingdom, including in pathogenic species, where they allow rapid adaptation to changing environmental conditions through selective inhibition of key cellular processes, such as DNA replication or protein translation. Under normal growth conditions, type II toxins are inhibited through tight protein-protein interaction with a cognate antitoxin protein. This toxin-antitoxin complex associates into a higher-order macromolecular structure, typically heterotetrameric or heterooctameric, exposing two DNA binding domains on the antitoxin that allow auto-regulation of transcription by direct binding to promoter DNA. In this chapter, we review our current understanding of the structural characteristics of type II toxin-antitoxin complexes in bacterial cells, with a special emphasis on the staggering variety of higher-order architecture observed among members of the VapBC family. This structural variety is a result of poor conservation at the primary sequence level and likely to have significant and functional implications on the way toxin-antitoxin expression is regulated.

  12. Higher-order interaction between molluscs and sheep affecting seedling numbers in grassland

    Science.gov (United States)

    Clear Hill, B. H.; Silvertown, J.

    Vertebrate and invertebrate herbivores are both important in mesotrophic grasslands and these two different classes of herbivore potentially interact in their effect upon plant populations. We used two field experiments to test for higher order interactions (HOIs) among sheep, slugs and seedlings, using the mechanistic definition that an HOI occurs when the presence of one species modifies the interaction between two others. In each experiment slug addition and slug-removal treatments were nested inside treatments that altered sheep grazing intensity and timing, and the emergence, of seedlings from experimentally sown seeds was monitored. In Experiment 1, seedling numbers of Cerastium fontanum were increased by intense summer grazing by sheep in both slug-addition and slugremoval treatment, but winter grazing by sheep only increased seedling emergence if slugs were removed. In Experiment 2, winter grazing by sheep significantly reduced total seedling emergence of four species sown ( Lotus corniculatus, Plantago lanceolata, Leucanthemum vulgare, Achillea millefolium), but the effect was only seen where slugs were removed. Though the experimental system is a relatively simple one with only four components (sheep, slugs, seedlings and the matrix vegetation), higher order interactions, a combination of direct and indirect effects and possible switching behaviour by slugs are all suggested by our results.

  13. Higher-order Multivariable Polynomial Regression to Estimate Human Affective States

    Science.gov (United States)

    Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

    2016-03-01

    From direct observations, facial, vocal, gestural, physiological, and central nervous signals, estimating human affective states through computational models such as multivariate linear-regression analysis, support vector regression, and artificial neural network, have been proposed in the past decade. In these models, linear models are generally lack of precision because of ignoring intrinsic nonlinearities of complex psychophysiological processes; and nonlinear models commonly adopt complicated algorithms. To improve accuracy and simplify model, we introduce a new computational modeling method named as higher-order multivariable polynomial regression to estimate human affective states. The study employs standardized pictures in the International Affective Picture System to induce thirty subjects’ affective states, and obtains pure affective patterns of skin conductance as input variables to the higher-order multivariable polynomial model for predicting affective valence and arousal. Experimental results show that our method is able to obtain efficient correlation coefficients of 0.98 and 0.96 for estimation of affective valence and arousal, respectively. Moreover, the method may provide certain indirect evidences that valence and arousal have their brain’s motivational circuit origins. Thus, the proposed method can serve as a novel one for efficiently estimating human affective states.

  14. Higher-order Multivariable Polynomial Regression to Estimate Human Affective States.

    Science.gov (United States)

    Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

    2016-03-21

    From direct observations, facial, vocal, gestural, physiological, and central nervous signals, estimating human affective states through computational models such as multivariate linear-regression analysis, support vector regression, and artificial neural network, have been proposed in the past decade. In these models, linear models are generally lack of precision because of ignoring intrinsic nonlinearities of complex psychophysiological processes; and nonlinear models commonly adopt complicated algorithms. To improve accuracy and simplify model, we introduce a new computational modeling method named as higher-order multivariable polynomial regression to estimate human affective states. The study employs standardized pictures in the International Affective Picture System to induce thirty subjects' affective states, and obtains pure affective patterns of skin conductance as input variables to the higher-order multivariable polynomial model for predicting affective valence and arousal. Experimental results show that our method is able to obtain efficient correlation coefficients of 0.98 and 0.96 for estimation of affective valence and arousal, respectively. Moreover, the method may provide certain indirect evidences that valence and arousal have their brain's motivational circuit origins. Thus, the proposed method can serve as a novel one for efficiently estimating human affective states.

  15. A geometric approach to higher-order Riccati chain: Darboux polynomials and constants of the motion

    Energy Technology Data Exchange (ETDEWEB)

    Carinena, Jose F; Ranada, Manuel F [Departamento de Fisica Teorica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Guha, Partha, E-mail: jfc@unizar.e, E-mail: partha@bose.res.i, E-mail: mfran@unizar.e [Max Planck Institute for Mathematics in the Sciences Inselstrasse 22, D-04103 Leipzig (Germany)

    2009-06-01

    The properties of higher-order Riccati equations are investigated. The second-order equation is a Lagrangian system and can be studied by using the symplectic formalism. The second-, third- and fourth-order cases are studied by proving the existence of Darboux functions. The corresponding cofactors are obtained and some related properties are discussed. The existence of generators of t-dependent constants of motion is also proved and then the expressions of the associated time-dependent first integrals are explicitly obtained. The connection of these time-dependent first integrals with the so-called master symmetries, characterizing some particular Hamiltonian systems, is also discussed. Finally the general n-th-order case is analyzed.

  16. Delaying or advancing higher-order sideband signals with active optomechanics

    CERN Document Server

    Jiao, Yafeng; Qian, Jun; Li, Yong; Jing, H

    2016-01-01

    We study the gain-assisted light transmissions in optomechanical systems, especially the nonlinear higher-order sideband process. We find that: (i) in a single active cavity, the efficiency of the second-order process is considerably enhanced, and the accompanying group delay can surpass that of the probe field, which is unattainable for a lossy cavity (i.e. without any gain); (ii) in an active-passive compound system, the second-order process can be further enhanced by approaching to the gain-loss balance, and hundreds of microsecond of relative delay or advance are achievable between the probe and the second-order signal, indicating an active optomechanical modulator both in frequency and time domains.

  17. Closed nominal rewriting and efficiently computable nominal algebra equality

    CERN Document Server

    Fernández, Maribel; 10.4204/EPTCS.34.5

    2010-01-01

    We analyse the relationship between nominal algebra and nominal rewriting, giving a new and concise presentation of equational deduction in nominal theories. With some new results, we characterise a subclass of equational theories for which nominal rewriting provides a complete procedure to check nominal algebra equality. This subclass includes specifications of the lambda-calculus and first-order logic.

  18. Infinitary Term Graph Rewriting is Simple, Sound and Complete

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Based on a simple metric and a simple partial order on term graphs, we develop two infinitary calculi of term graph rewriting. We show that, similarly to infinitary term rewriting, the partial order formalisation yields a conservative extension of the metric formalisation of the calculus. By show...

  19. Closed nominal rewriting and efficiently computable nominal algebra equality

    Directory of Open Access Journals (Sweden)

    Maribel Fernández

    2010-09-01

    Full Text Available We analyse the relationship between nominal algebra and nominal rewriting, giving a new and concise presentation of equational deduction in nominal theories. With some new results, we characterise a subclass of equational theories for which nominal rewriting provides a complete procedure to check nominal algebra equality. This subclass includes specifications of the lambda-calculus and first-order logic.

  20. Mathematics Teachers’ Interpretation of Higher-Order Thinking in Bloom’s Taxonomy

    OpenAIRE

    Tony Thompson

    2008-01-01

    This study investigated mathematics teachers’ interpretation of higher-order thinking in Bloom’s Taxonomy. Thirty-two high school mathematics teachers from the southeast U.S. were asked to (a) define lower- and higher-order thinking, (b) identify which thinking skills in Bloom’s Taxonomy represented lower- and higher-order thinking, and (c) create an Algebra I final exam item representative of each thinking skill. Results indicate that mathematics teachers have difficulty interpreting the thi...

  1. Adaptive Integral Method for Higher-Order Hierarchical Method of Moments

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Meincke, Peter

    2006-01-01

    The Adaptive Integral Method (AIM) is applied to solve the volume integral equation in conjunction with the higher-order Method of Moments (MoM). The classical AIM is modified for larger discretization cells to take advantage of higher-order MoM. The technique combines the low computational...... complexity and memory requirements of AIM with the reduced number of unknowns and higher-order convergence of higher-order hierarchical Legendre basis functions. Numerical examples given show the advantages of the proposed technique over AIM based on low-order basis functions in terms of memory...

  2. Probing higher order correlations of the photon field with photon number resolving avalanche photodiodes.

    Science.gov (United States)

    Dynes, J F; Yuan, Z L; Sharpe, A W; Thomas, O; Shields, A J

    2011-07-04

    We demonstrate the use of two high speed avalanche photodiodes in exploring higher order photon correlations. By employing the photon number resolving capability of the photodiodes the response to higher order photon coincidences can be measured. As an example we show experimentally the sensitivity to higher order correlations for three types of photon sources with distinct photon statistics. This higher order correlation technique could be used as a low cost and compact tool for quantifying the degree of correlation of photon sources employed in quantum information science.

  3. Non-relativistic particle higher-order harmonic radiation based short-wavelength laser and the operation stability

    Institute of Scientific and Technical Information of China (English)

    LUO Xiao-hua; WU Mu-ying; HE Wei; SHAO Ming-zhu; LUO Shi-yu

    2011-01-01

    Under classical mechanics, the general equation of particle motion in the periodic field is derived. In the dampless case, the existence possibility of the higher-order harmonic radiation is explored by using Bessel function expansion of a generalized trigonometrical function and the multi-scale method. In the damping case, the critical properties and a chaotic behavior are discussed by the Melnikov method. The results show that the use of a higher-order harmonic radiation of non-relativistic particles as a short-wavelength laser source is perfectly possible, and the system's critical condition is related to its parameters. Only by adjusting parameters suitablely, the stable higher-order harmonic radiation with bigger intensity can be obtained.

  4. Higher-order rational solitons and rogue-like wave solutions of the (2 + 1)-dimensional nonlinear fluid mechanics equations

    Science.gov (United States)

    Wen, Xiao-Yong; Yan, Zhenya

    2017-02-01

    The novel generalized perturbation (n, M)-fold Darboux transformations (DTs) are reported for the (2 + 1)-dimensional Kadomtsev-Petviashvili (KP) equation and its extension by using the Taylor expansion of the Darboux matrix. The generalized perturbation (1 , N - 1) -fold DTs are used to find their higher-order rational solitons and rogue wave solutions in terms of determinants. The dynamics behaviors of these rogue waves are discussed in detail for different parameters and time, which display the interesting RW and soliton structures including the triangle, pentagon, heptagon profiles, etc. Moreover, we find that a new phenomenon that the parameter (a) can control the wave structures of the KP equation from the higher-order rogue waves (a ≠ 0) into higher-order rational solitons (a = 0) in (x, t)-space with y = const . These results may predict the corresponding dynamical phenomena in the models of fluid mechanics and other physically relevant systems.

  5. Design and construction of higher-order structure and function in proteinosome-based protocells.

    Science.gov (United States)

    Huang, Xin; Patil, Avinash J; Li, Mei; Mann, Stephen

    2014-06-25

    The design and construction of higher-order structure and function in proteinosome microcompartments enclosed by a cross-linked membrane of amphiphilic bovine serum albumin/poly(N-isopropylacrylamide) (BSA-NH2/PNIPAAm) nanoconjugates is described. Three structure/function relationships are investigated: (i) differential chemical cross-linking for the control of membrane disassembly and regulated release of encapsulated genetic polymers; (ii) enzyme-mediated hydrogel structuring of the internal microenvironment to increase mechanical robustness and generate a molecularly crowded reaction environment; and (iii) self-production of a membrane-enclosing outer hydrogel wall for generating protease-resistant forms of the protein-polymer protocells. Our results highlight the potential of integrating aspects of supramolecular and polymer chemistry into the design and construction of novel bioinspired microcompartments as a step toward small-scale materials systems based on synthetic cellularity.

  6. Higher-order analogues of the unitarity condition for quantum R-matrices

    Science.gov (United States)

    Zotov, A. V.

    2016-11-01

    We derive a family of nth-order identities for quantum R-matrices of the Baxter-Belavin type in the fundamental representation. The set of identities includes the unitarity condition as the simplest case (n = 2). Our study is inspired by the fact that the third-order identity provides commutativity of the Knizhnik-Zamolodchikov-Bernard connections. On the other hand, the same identity yields the R-matrix-valued Lax pairs for classical integrable systems of Calogero type, whose construction uses the interpretation of the quantum R-matrix as a matrix generalization of the Kronecker function. We present a proof of the higher-order scalar identities for the Kronecker functions, which is then naturally generalized to R-matrix identities.

  7. Higher order analogues of unitarity condition for quantum R-matrices

    CERN Document Server

    Zotov, A

    2015-01-01

    We prove a family of $n$-th order identities for quantum $R$-matrices of Baxter-Belavin type in fundamental representation. The set of identities includes the unitarity condition as the simplest one ($n=2$). Our study is inspired by the fact that the third order identity provides commutativity of the Knizhnik-Zamolodchikov-Bernard connections. On the other hand the same identity gives rise to $R$-matrix valued Lax pairs for the classical integrable systems of Calogero type. The latter construction uses interpretation of quantum $R$-matrix as matrix generalization of the Kronecker function. We present a proof of the higher order scalar identities for the Kronecker functions which is then naturally generalized to the $R$-matrix identities.

  8. Azimuthal correlations and mixed higher order flow harmonics from CMS at the LHC

    CERN Document Server

    Stojanovic, Milan

    2017-01-01

    Two-particle correlations measurements of $v_{n}$ (n=2-4) in 8.16 TeV pPb collisions, and event-by-event correlations of different $v_{n}$ measured using symmetric cumulants in 13 TeV pp, 5.02 and 8.16TeV pPb and 5.02 TeV PbPb collisions at the LHC. These new results give important insights to the origin of collectivity observed in small collision systems. Additionally, using the scalar product method and the method of two-particle correlations, the mixed higher order flow harmonics and extracted nonlinear response coefficients of charged particles are measured for the first time as a function of $p_{T}$ and centrality in 2.76 and 5.02 TeV PbPb collisions. The obtained results are compared with different theoretical predictions.

  9. Measurement of electrodynamics characteristics of higher order modes for harmonic cavity at 2400 MHz

    Science.gov (United States)

    Shashkov, Ya V.; Sobenin, N. P.; Gusarova, M. A.; Lalayan, M. V.; Bazyl, D. S.; Donetskiy, R. V.; Orlov, A. I.; Zobov, M. M.; Zavadtsev, A. A.

    2016-09-01

    In the frameworks of the High Luminosity Large Hadron Collider (HL-LHC) upgrade program an application of additional superconducting harmonic cavities operating at 800 MHz is currently under discussion. As a possible candidate, an assembly of two cavities with grooved beam pipes connected by a drift tube and housed in a common cryomodule, was proposed. In this article we discuss measurements of loaded Q-factors of higher order modes (HOM) performed on a scaled aluminium single cell cavity prototype with the fundamental frequency of 2400 MHz and on an array of two such cavities connected by a narrow beam pipe. The measurements were performed for the system with and without the matching load in the drift tube..

  10. Higher-order Solution of Stochastic Diffusion equation with Nonlinear Losses Using WHEP technique

    KAUST Repository

    El-Beltagy, Mohamed A.

    2014-01-06

    Using Wiener-Hermite expansion with perturbation (WHEP) technique in the solution of the stochastic partial differential equations (SPDEs) has the advantage of converting the problem to a system of deterministic equations that can be solved efficiently using the standard deterministic numerical methods [1]. The Wiener-Hermite expansion is the only known expansion that handles the white/colored noise exactly. The main statistics, such as the mean, covariance, and higher order statistical moments, can be calculated by simple formulae involving only the deterministic Wiener-Hermite coefficients. In this poster, the WHEP technique is used to solve the 2D diffusion equation with nonlinear losses and excited with white noise. The solution will be obtained numerically and will be validated and compared with the analytical solution that can be obtained from any symbolic mathematics package such as Mathematica.

  11. Expression QTL modules as functional components underlying higher-order phenotypes.

    Directory of Open Access Journals (Sweden)

    Lei Bao

    Full Text Available Systems genetics studies often involve the mapping of numerous regulatory relations between genetic loci and expression traits. These regulatory relations form a bipartite network consisting of genetic loci and expression phenotypes. Modular network organizations may arise from the pleiotropic and polygenic regulation of gene expression. Here we analyzed the expression QTL (eQTL networks derived from expression genetic data of yeast and mouse liver and found 65 and 98 modules respectively. Computer simulation result showed that such modules rarely occurred in randomized networks with the same number of nodes and edges and same degree distribution. We also found significant within-module functional coherence. The analysis of genetic overlaps and the evidences from biomedical literature have linked some eQTL modules to physiological phenotypes. Functional coherence within the eQTL modules and genetic overlaps between the modules and physiological phenotypes suggests that eQTL modules may act as functional units underlying the higher-order phenotypes.

  12. Higher order structure of short immunostimulatory oligonucleotides studied by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Dionne C.G., E-mail: dionne.c.g.klein@ntnu.no [Department of Physics, Norwegian University of Science and Technology, N-7491, Trondheim (Norway); Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Latz, Eicke [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605 (United States); Institute of Innate Immunity, University Hospitals, University of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn (Germany); Espevik, Terje [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489, Trondheim (Norway); Stokke, Bjorn T. [Department of Physics, Norwegian University of Science and Technology, N-7491, Trondheim (Norway)

    2010-05-15

    Immunostimulatory CpG-DNA activates the innate immune system by binding to Toll-like receptor 9. Structurally different CpG-containing oligonucleotides trigger a different type of immune response while activating the same receptor. We therefore investigated the higher order structure of two different classes of immunostimulatory CpG-DNA. Class A, which contains a partly self-complementary sequence and poly-G ends, forms duplexes and nanoparticles in salt solution, while class B, which does not contain these features and is purely linear, does not form a duplex or nanoparticles. Results obtained here by high-resolution atomic force microscopy of classes A and B CpG-DNA, reflect these differences in secondary structure. Detailed structural analysis of the atomic force microscopy topographs is presented for two different sample preparation methods.

  13. A HIGHER-ORDER NON-HYDROSTATIC MODEL FOR SIMULATING WAVE PROPAGATION OVER IRREGULAR BOTTOMS

    Institute of Scientific and Technical Information of China (English)

    AI Cong-fang; XING Yah; JIN Sheng

    2011-01-01

    A higher-order non-hydrostatic model is developed to simulate the wave propagation over irregular bottoms based on a vertical boundary-fitted coordinate system.In the model,an explicit projection method is adopted to solve the unsteady Euler equations.Advection terms are integrated explicitly with the MacCormack's scheme,with a second-order accuracy in both space and time.Two classical examples of surface wave propagation are used to demonstrate the capability of the model.It is found that the model with only two vertical layers could accurately simulate the motion of waves,including wave shoaling,nonlinearity,dispersion,refraction,and diffraction phenomena.

  14. Abstract Certification of Global Non-Interference in Rewriting Logic

    CERN Document Server

    Alba-Castro, Mauricio; Escobar, Santiago

    2010-01-01

    Non-interference is a semantic program property that assigns confidentiality levels to data objects and prevents illicit information flows from occurring from high to low security levels. In this paper, we present a novel security model for global non-interference which approximates non-interference as a safety property. We also propose a certification technique for global non-interference of complete Java classes based on rewriting logic, a very general logical and semantic framework that is efficiently implemented in the high-level programming language Maude. Starting from an existing Java semantics specification written in Maude, we develop an extended, information-flow Java semantics that allows us to correctly observe global non-interference policies. In order to achieve a finite state transition system, we develop an abstract Java semantics that we use for secure and effective non-interference Java analysis. The analysis produces certificates that are independently checkable and are small enough to be u...

  15. Higher-Order Beta Matching with Solutions in Long Beta-Eta Normal Form

    DEFF Research Database (Denmark)

    Støvring, Kristian

    2006-01-01

    up to beta-eta equivalence is a long-standing open problem.We show that higher-order matching up to beta-eta equivalence is decidable if and only if a restricted form of higher-order matching up to beta equivalence is decidable: the restriction is that solutions must be in long beta-eta normal form....

  16. On the Higher Power Sums of Reciprocal Higher-Order Sequences

    Directory of Open Access Journals (Sweden)

    Zhengang Wu

    2014-01-01

    Full Text Available Let {un} be a higher-order linear recursive sequence. In this paper, we use the properties of error estimation and the analytic method to study the reciprocal sums of higher power of higher-order sequences. Then we establish several new and interesting identities relating to the infinite and finite sums.

  17. Analysis of Scattering by Inhomogeneous Dielectric Objects Using Higher-Order Hierarchical MoM

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter;

    2003-01-01

    developed higher-order hierarchical Legendre basis functions for expansion of the electric flux density and higher-order geometry modeling. An unstructured mesh composed by trilinear (8-node) and/or curved (27-node) hexahedral elements is used to represent the dielectric object accurately. It is shown...

  18. Generalized q-Euler Numbers and Polynomials of Higher Order and Some Theoretic Identities

    Directory of Open Access Journals (Sweden)

    T. Kim

    2010-01-01

    Full Text Available We give a new construction of the q-Euler numbers and polynomials of higher order attached to Dirichlet's character χ. We derive some theoretic identities involving the generalized q-Euler numbers and polynomials of higher order.

  19. Assessing School Work Culture: A Higher-Order Analysis and Strategy.

    Science.gov (United States)

    Johnson, William L.; Johnson, Annabel M.; Zimmerman, Kurt J.

    This paper reviews a work culture productivity model and reports the development of a work culture instrument based on the culture productivity model. Higher order principal components analysis was used to assess work culture, and a third-order factor analysis shows how the first-order factors group into higher-order factors. The school work…

  20. Higher Order Thinking Skills among Secondary School Students in Science Learning

    Science.gov (United States)

    Saido, Gulistan Mohammed; Siraj, Saedah; Bin Nordin, Abu Bakar; Al Amedy, Omed Saadallah

    2015-01-01

    A central goal of science education is to help students to develop their higher order thinking skills to enable them to face the challenges of daily life. Enhancing students' higher order thinking skills is the main goal of the Kurdish Science Curriculum in the Iraqi-Kurdistan region. This study aimed at assessing 7th grade students' higher order…