WorldWideScience

Sample records for algorithmic algebraic model

  1. Performance modeling and prediction for linear algebra algorithms

    OpenAIRE

    Iakymchuk, Roman

    2012-01-01

    This dissertation incorporates two research projects: performance modeling and prediction for dense linear algebra algorithms, and high-performance computing on clouds. The first project is focused on dense matrix computations, which are often used as computational kernels for numerous scientific applications. To solve a particular mathematical operation, linear algebra libraries provide a variety of algorithms. The algorithm of choice depends, obviously, on its performance. Performance of su...

  2. Symplectic algebraic dynamics algorithm

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the algebraic dynamics solution of ordinary differential equations andintegration of  ,the symplectic algebraic dynamics algorithm sn is designed,which preserves the local symplectic geometric structure of a Hamiltonian systemand possesses the same precision of the na ve algebraic dynamics algorithm n.Computer experiments for the 4th order algorithms are made for five test modelsand the numerical results are compared with the conventional symplectic geometric algorithm,indicating that sn has higher precision,the algorithm-inducedphase shift of the conventional symplectic geometric algorithm can be reduced,and the dynamical fidelity can be improved by one order of magnitude.

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  4. Algebraic dynamics algorithm:Numerical comparison with Runge-Kutta algorithm and symplectic geometric algorithm

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the exact analytical solution of ordinary differential equations, a truncation of the Taylor series of the exact solution to the Nth order leads to the Nth order algebraic dynamics algorithm. A detailed numerical comparison is presented with Runge-Kutta algorithm and symplectic geometric algorithm for 12 test models. The results show that the algebraic dynamics algorithm can better preserve both geometrical and dynamical fidelity of a dynamical system at a controllable precision, and it can solve the problem of algorithm-induced dissipation for the Runge-Kutta algorithm and the problem of algorithm-induced phase shift for the symplectic geometric algorithm.

  5. Algebraic dynamics algorithm: Numerical comparison with Runge-Kutta algorithm and symplectic geometric algorithm

    Institute of Scientific and Technical Information of China (English)

    WANG ShunJin; ZHANG Hua

    2007-01-01

    Based on the exact analytical solution of ordinary differential equations,a truncation of the Taylor series of the exact solution to the Nth order leads to the Nth order algebraic dynamics algorithm.A detailed numerical comparison is presented with Runge-Kutta algorithm and symplectic geometric algorithm for 12 test models.The results show that the algebraic dynamics algorithm can better preserve both geometrical and dynamical fidelity of a dynamical system at a controllable precision,and it can solve the problem of algorithm-induced dissipation for the Runge-Kutta algorithm and the problem of algorithm-induced phase shift for the symplectic geometric algorithm.

  6. Parallel algorithms for numerical linear algebra

    CERN Document Server

    van der Vorst, H

    1990-01-01

    This is the first in a new series of books presenting research results and developments concerning the theory and applications of parallel computers, including vector, pipeline, array, fifth/future generation computers, and neural computers.All aspects of high-speed computing fall within the scope of the series, e.g. algorithm design, applications, software engineering, networking, taxonomy, models and architectural trends, performance, peripheral devices.Papers in Volume One cover the main streams of parallel linear algebra: systolic array algorithms, message-passing systems, algorithms for p

  7. Optimal Algorithm for Algebraic Factoring

    Institute of Scientific and Technical Information of China (English)

    支丽红

    1997-01-01

    This paper presents on optimized method for factoring multivariate polynomials over algebraic extension fields defined by an irreducible ascending set. The basic idea is to convert multivariate polynomials to univariate polynomials and algebraic extension fields to algebraic number fields by suitable integer substituteions.Then factorize the univariate polynomials over the algebraic number fields.Finally,construct mulativariate factors of the original polynomial by Hensel lemma and TRUEFACTOR test.Some examples with timing are included.

  8. Linear algebra algorithms for divisors on an algebraic curve

    OpenAIRE

    Khuri-Makdisi, Kamal

    2001-01-01

    We use an embedding of the symmetric $d$th power of any algebraic curve $C$ of genus $g$ into a Grassmannian space to give algorithms for working with divisors on $C$, using only linear algebra in vector spaces of dimension $O(g)$, and matrices of size $O(g^2)\\times O(g)$. When the base field $k$ is finite, or if $C$ has a rational point over $k$, these give algorithms for working on the Jacobian of $C$ that require $O(g^4)$ field operations, arising from the Gaussian elimination. Our point o...

  9. Algebraic Reconstruction Algorithm of Vapor Tomography

    Directory of Open Access Journals (Sweden)

    HE Lin

    2015-01-01

    Full Text Available While applying algebraic reconstruction algorithm in vapor tomography, problems have to be solved with respect to constructing the constraint condition, selecting the initial value, calculating optimal relaxation factor and deciding the iteration termination condition. Golden section search method and NCP termination rule are given to solve the latter two problems, respectively. Eight algebraic reconstruction algorithms, including Kaczmarz, Randkaczmarz, Symkaczmarz, SART, Landweber, Cimmino, CAV and DROP algorithm, are comparatively analyzed and tested by the data from SatRef station in Hong Kong. The results show that all the eight algorithms can satisfy the requirements of vapor tomography and the iteration termination condition is more important than the relaxation condition. While the golden section method and NCP method are used, the CAV algorithm performs best, and then the Cimmino algorithm.

  10. Lie 2-algebra models

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, Patricia [Centro de Estudios Científicos (CECs),Avenida Arturo Prat 514, Valdivia (Chile); Sämann, Christian [Maxwell Institute for Mathematical Sciences,Department of Mathematics, Heriot-Watt University,Colin Maclaurin Building, Riccarton, Edinburgh EH14 4AS (United Kingdom)

    2014-04-09

    In this paper, we begin the study of zero-dimensional field theories with fields taking values in a semistrict Lie 2-algebra. These theories contain the IKKT matrix model and various M-brane related models as special cases. They feature solutions that can be interpreted as quantized 2-plectic manifolds. In particular, we find solutions corresponding to quantizations of ℝ{sup 3}, S{sup 3} and a five-dimensional Hpp-wave. Moreover, by expanding a certain class of Lie 2-algebra models around the solution corresponding to quantized ℝ{sup 3}, we obtain higher BF-theory on this quantized space.

  11. Lie 2-algebra models

    International Nuclear Information System (INIS)

    In this paper, we begin the study of zero-dimensional field theories with fields taking values in a semistrict Lie 2-algebra. These theories contain the IKKT matrix model and various M-brane related models as special cases. They feature solutions that can be interpreted as quantized 2-plectic manifolds. In particular, we find solutions corresponding to quantizations of ℝ3, S3 and a five-dimensional Hpp-wave. Moreover, by expanding a certain class of Lie 2-algebra models around the solution corresponding to quantized ℝ3, we obtain higher BF-theory on this quantized space

  12. An Algebraic Hardware/Software Partitioning Algorithm

    Institute of Scientific and Technical Information of China (English)

    秦胜潮; 何积丰; 裘宗燕; 张乃孝

    2002-01-01

    Hardware and software co-design is a design technique which delivers computer systems comprising hardware and software components. A critical phase of the co-design process is to decompose a program into hardware and software. This paper proposes an algebraic partitioning algorithm whose correctness is verified in program algebra. The authors introduce a program analysis phase before program partitioning and develop a collection of syntax-based splitting rules. The former provides the information for moving operations from software to hardware and reducing the interaction between components, and the latter supports a compositional approach to program partitioning.

  13. Comparison of an algebraic multigrid algorithm to two iterative solvers used for modeling ground water flow and transport.

    Science.gov (United States)

    Detwiler, Russell L; Mehl, Steffen; Rajaram, Harihar; Cheung, Wendy W

    2002-01-01

    Numerical solution of large-scale ground water flow and transport problems is often constrained by the convergence behavior of the iterative solvers used to solve the resulting systems of equations. We demonstrate the ability of an algebraic multigrid algorithm (AMG) to efficiently solve the large, sparse systems of equations that result from computational models of ground water flow and transport in large and complex domains. Unlike geometric multigrid methods, this algorithm is applicable to problems in complex flow geometries, such as those encountered in pore-scale modeling of two-phase flow and transport. We integrated AMG into MODFLOW 2000 to compare two- and three-dimensional flow simulations using AMG to simulations using PCG2, a preconditioned conjugate gradient solver that uses the modified incomplete Cholesky preconditioner and is included with MODFLOW 2000. CPU times required for convergence with AMG were up to 140 times faster than those for PCG2. The cost of this increased speed was up to a nine-fold increase in required random access memory (RAM) for the three-dimensional problems and up to a four-fold increase in required RAM for the two-dimensional problems. We also compared two-dimensional numerical simulations of steady-state transport using AMG and the generalized minimum residual method with an incomplete LU-decomposition preconditioner. For these transport simulations, AMG yielded increased speeds of up to 17 times with only a 20% increase in required RAM. The ability of AMG to solve flow and transport problems in large, complex flow systems and its ready availability make it an ideal solver for use in both field-scale and pore-scale modeling. PMID:12019641

  14. Homogeneous Buchberger algorithms and Sullivant's computational commutative algebra challenge

    DEFF Research Database (Denmark)

    Lauritzen, Niels

    2005-01-01

    We give a variant of the homogeneous Buchberger algorithm for positively graded lattice ideals. Using this algorithm we solve the Sullivant computational commutative algebra challenge.......We give a variant of the homogeneous Buchberger algorithm for positively graded lattice ideals. Using this algorithm we solve the Sullivant computational commutative algebra challenge....

  15. Algebraic dynamics solution to and algebraic dynamics algorithm for nonlinear advection equation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Algebraic dynamics approach and algebraic dynamics algorithm for the solution of nonlinear partial differential equations are applied to the nonlinear advection equa-tion. The results show that the approach is effective for the exact analytical solu-tion and the algorithm has higher precision than other existing algorithms in nu-merical computation for the nonlinear advection equation.

  16. Optical linear algebra processors - Architectures and algorithms

    Science.gov (United States)

    Casasent, David

    1986-01-01

    Attention is given to the component design and optical configuration features of a generic optical linear algebra processor (OLAP) architecture, as well as the large number of OLAP architectures, number representations, algorithms and applications encountered in current literature. Number-representation issues associated with bipolar and complex-valued data representations, high-accuracy (including floating point) performance, and the base or radix to be employed, are discussed, together with case studies on a space-integrating frequency-multiplexed architecture and a hybrid space-integrating and time-integrating multichannel architecture.

  17. Observable Algebra in Field Algebra of G-spin Models

    Institute of Scientific and Technical Information of China (English)

    蒋立宁

    2003-01-01

    Field algebra of G-spin models can provide the simplest examples of lattice field theory exhibiting quantum symmetry. Let D(G) be the double algebra of a finite group G and D(H), a sub-algebra of D(G) determined by subgroup H of G. This paper gives concrete generators and the structure of the observable algebra AH, which is a D(H)-invariant sub-algebra in the field algebra of G-spin models F, and shows that AH is a C*-algebra. The correspondence between H and AH is strictly monotonic. Finally, a duality between D(H) and AH is given via an irreducible vacuum C*-representation of F.

  18. Solving stochastic epidemiological models using computer algebra

    Science.gov (United States)

    Hincapie, Doracelly; Ospina, Juan

    2011-06-01

    Mathematical modeling in Epidemiology is an important tool to understand the ways under which the diseases are transmitted and controlled. The mathematical modeling can be implemented via deterministic or stochastic models. Deterministic models are based on short systems of non-linear ordinary differential equations and the stochastic models are based on very large systems of linear differential equations. Deterministic models admit complete, rigorous and automatic analysis of stability both local and global from which is possible to derive the algebraic expressions for the basic reproductive number and the corresponding epidemic thresholds using computer algebra software. Stochastic models are more difficult to treat and the analysis of their properties requires complicated considerations in statistical mathematics. In this work we propose to use computer algebra software with the aim to solve epidemic stochastic models such as the SIR model and the carrier-borne model. Specifically we use Maple to solve these stochastic models in the case of small groups and we obtain results that do not appear in standard textbooks or in the books updated on stochastic models in epidemiology. From our results we derive expressions which coincide with those obtained in the classical texts using advanced procedures in mathematical statistics. Our algorithms can be extended for other stochastic models in epidemiology and this shows the power of computer algebra software not only for analysis of deterministic models but also for the analysis of stochastic models. We also perform numerical simulations with our algebraic results and we made estimations for the basic parameters as the basic reproductive rate and the stochastic threshold theorem. We claim that our algorithms and results are important tools to control the diseases in a globalized world.

  19. FOUNDATION OF NUCLEAR ALGEBRAIC MODELS

    Institute of Scientific and Technical Information of China (English)

    周孝谦

    1990-01-01

    Based upon Tomonoga-Rowe's many body theory, we find that the algebraic models, including IBM and FDSM are simplest extension of Rowe-Rosensteel's sp(3R).Dynkin-Gruber's subalgebra embedding method is applied to find an appropriate algebra and it's reduction chains conforming to physical requirement. The separated cases sp(6) and so(8) now appear as two branches stemming from the same root D6-O(12). Transitional ease between sp(6) and so(8) is inherently include.

  20. Algebraic dynamics solutions and algebraic dynamics algorithm for nonlinear ordinary differential equations

    Institute of Scientific and Technical Information of China (English)

    WANG; Shunjin; ZHANG; Hua

    2006-01-01

    The problem of preserving fidelity in numerical computation of nonlinear ordinary differential equations is studied in terms of preserving local differential structure and approximating global integration structure of the dynamical system.The ordinary differential equations are lifted to the corresponding partial differential equations in the framework of algebraic dynamics,and a new algorithm-algebraic dynamics algorithm is proposed based on the exact analytical solutions of the ordinary differential equations by the algebraic dynamics method.In the new algorithm,the time evolution of the ordinary differential system is described locally by the time translation operator and globally by the time evolution operator.The exact analytical piece-like solution of the ordinary differential equations is expressd in terms of Taylor series with a local convergent radius,and its finite order truncation leads to the new numerical algorithm with a controllable precision better than Runge Kutta Algorithm and Symplectic Geometric Algorithm.

  1. Efficient computer algebra algorithms for polynomial matrices in control design

    Science.gov (United States)

    Baras, J. S.; Macenany, D. C.; Munach, R.

    1989-01-01

    The theory of polynomial matrices plays a key role in the design and analysis of multi-input multi-output control and communications systems using frequency domain methods. Examples include coprime factorizations of transfer functions, cannonical realizations from matrix fraction descriptions, and the transfer function design of feedback compensators. Typically, such problems abstract in a natural way to the need to solve systems of Diophantine equations or systems of linear equations over polynomials. These and other problems involving polynomial matrices can in turn be reduced to polynomial matrix triangularization procedures, a result which is not surprising given the importance of matrix triangularization techniques in numerical linear algebra. Matrices with entries from a field and Gaussian elimination play a fundamental role in understanding the triangularization process. In the case of polynomial matrices, matrices with entries from a ring for which Gaussian elimination is not defined and triangularization is accomplished by what is quite properly called Euclidean elimination. Unfortunately, the numerical stability and sensitivity issues which accompany floating point approaches to Euclidean elimination are not very well understood. New algorithms are presented which circumvent entirely such numerical issues through the use of exact, symbolic methods in computer algebra. The use of such error-free algorithms guarantees that the results are accurate to within the precision of the model data--the best that can be hoped for. Care must be taken in the design of such algorithms due to the phenomenon of intermediate expressions swell.

  2. Impact of hierarchical memory systems on linear algebra algorithm design

    Energy Technology Data Exchange (ETDEWEB)

    Gallivan, K.; Jalby, W.; Meier, U.; Sameh, A.H.

    1988-01-01

    Linear algebra algorithms based on the BLAS or extended BLAS do not achieve high performance on multivector processors with a hierarchical memory system because of a lack of data locality. For such machines, block linear algebra algorithms must be implemented in terms of matrix-matrix primitives (BLAS3). Designing efficient linear algebra algorithms for these architectures requires analysis of the behavior of the matrix-matrix primitives and the resulting block algorithms as a function of certain system parameters. The analysis must identify the limits of performance improvement possible via blocking and any contradictory trends that require trade-off consideration. The authors propose a methodology that facilitates such an analysis and use it to analyze the performance of the BLAS3 primitives used in block methods. A similar analysis of the block size-performance relationship is also performed at the algorithm level for block versions of the LU decomposition and the Gram-Schmidt orthogonalization procedures.

  3. Algebraic dynamics solutions and algebraic dynamics algorithm for nonlinear partial differential evolution equations of dynamical systems

    Institute of Scientific and Technical Information of China (English)

    WANG Shundin; ZHANG Hua

    2008-01-01

    Using functional derivative technique In quantum field theory,the algebraic dy-namics approach for solution of ordinary differential evolution equations was gen-eralized to treat partial differential evolution equations.The partial differential evo-lution equations were lifted to the corresponding functional partial differential equations in functional space by Introducing the time translation operator.The functional partial differential evolution equations were solved by algebraic dynam-ics.The algebraic dynamics solutions are analytical In Taylor series In terms of both initial functions and time.Based on the exact analytical solutions,a new nu-merical algorithm-algebraic dynamics algorithm was proposed for partial differ-ential evolution equations.The difficulty of and the way out for the algorithm were discussed.The application of the approach to and computer numerical experi-ments on the nonlinear Burgers equation and meteorological advection equation indicate that the algebraic dynamics approach and algebraic dynamics algorithm are effective to the solution of nonlinear partial differential evolution equations both analytically and numerically.

  4. A spatial operator algebra for manipulator modeling and control

    Science.gov (United States)

    Rodriguez, G.; Jain, A.; Kreutz-Delgado, K.

    1991-01-01

    A recently developed spatial operator algebra for manipulator modeling, control, and trajectory design is discussed. The elements of this algebra are linear operators whose domain and range spaces consist of forces, moments, velocities, and accelerations. The effect of these operators is equivalent to a spatial recursion along the span of a manipulator. Inversion of operators can be efficiently obtained via techniques of recursive filtering and smoothing. The operator algebra provides a high-level framework for describing the dynamic and kinematic behavior of a manipulator and for control and trajectory design algorithms. The interpretation of expressions within the algebraic framework leads to enhanced conceptual and physical understanding of manipulator dynamics and kinematics.

  5. Specific optimization of genetic algorithm on special algebras

    Science.gov (United States)

    Habiballa, Hashim; Novak, Vilem; Dyba, Martin; Schenk, Jiri

    2016-06-01

    Searching for complex finite algebras can be succesfully done by the means of genetic algorithm as we showed in former works. This genetic algorithm needs specific optimization of crossover and mutation. We present details about these optimizations which are already implemented in software application for this task - EQCreator.

  6. Applied algebra codes, ciphers and discrete algorithms

    CERN Document Server

    Hardy, Darel W; Walker, Carol L

    2009-01-01

    This book attempts to show the power of algebra in a relatively simple setting.-Mathematical Reviews, 2010… The book supports learning by doing. In each section we can find many examples which clarify the mathematics introduced in the section and each section is followed by a series of exercises of which approximately half are solved in the end of the book. Additional the book comes with a CD-ROM containing an interactive version of the book powered by the computer algebra system Scientific Notebook. … the mathematics in the book are developed as needed and the focus of the book lies clearly o

  7. Algebraic dynamics solutions and algebraic dynamics algorithm for nonlinear partial differential evolution equations of dynamical systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Using functional derivative technique in quantum field theory, the algebraic dy-namics approach for solution of ordinary differential evolution equations was gen-eralized to treat partial differential evolution equations. The partial differential evo-lution equations were lifted to the corresponding functional partial differential equations in functional space by introducing the time translation operator. The functional partial differential evolution equations were solved by algebraic dynam-ics. The algebraic dynamics solutions are analytical in Taylor series in terms of both initial functions and time. Based on the exact analytical solutions, a new nu-merical algorithm—algebraic dynamics algorithm was proposed for partial differ-ential evolution equations. The difficulty of and the way out for the algorithm were discussed. The application of the approach to and computer numerical experi-ments on the nonlinear Burgers equation and meteorological advection equation indicate that the algebraic dynamics approach and algebraic dynamics algorithm are effective to the solution of nonlinear partial differential evolution equations both analytically and numerically.

  8. High performance linear algebra algorithms: An introduction

    DEFF Research Database (Denmark)

    Gustavson, F.G.; Wasniewski, Jerzy

    2006-01-01

    his Mini-Symposium consisted of two back to back sessions, each consisting of five presentations, held on the afternoon of Monday, June 21, 2004. A major theme of both sessions was novel data structures for the matrices of dense linear algebra, DLA. Talks one to four of session one all centered...

  9. An Improved Algorithm for Generating Database Transactions from Relational Algebra Specifications

    Directory of Open Access Journals (Sweden)

    Daniel J. Dougherty

    2010-03-01

    Full Text Available Alloy is a lightweight modeling formalism based on relational algebra. In prior work with Fisler, Giannakopoulos, Krishnamurthi, and Yoo, we have presented a tool, Alchemy, that compiles Alloy specifications into implementations that execute against persistent databases. The foundation of Alchemy is an algorithm for rewriting relational algebra formulas into code for database transactions. In this paper we report on recent progress in improving the robustness and efficiency of this transformation.

  10. An Improved Algorithm for Generating Database Transactions from Relational Algebra Specifications

    OpenAIRE

    Dougherty, Daniel J.

    2010-01-01

    Alloy is a lightweight modeling formalism based on relational algebra. In prior work with Fisler, Giannakopoulos, Krishnamurthi, and Yoo, we have presented a tool, Alchemy, that compiles Alloy specifications into implementations that execute against persistent databases. The foundation of Alchemy is an algorithm for rewriting relational algebra formulas into code for database transactions. In this paper we report on recent progress in improving the robustness and efficiency of this transforma...

  11. An Improved Algorithm for Generating Database Transactions from Relational Algebra Specifications

    CERN Document Server

    Dougherty, Daniel J

    2010-01-01

    Alloy is a lightweight modeling formalism based on relational algebra. In prior work with Fisler, Giannakopoulos, Krishnamurthi, and Yoo, we have presented a tool, Alchemy, that compiles Alloy specifications into implementations that execute against persistent databases. The foundation of Alchemy is an algorithm for rewriting relational algebra formulas into code for database transactions. In this paper we report on recent progress in improving the robustness and efficiency of this transformation.

  12. Computing Small 1-Homological Models for Commutative Differential Graded Algebras

    OpenAIRE

    Alvarez, Victor; Armario, Jose Andres; Frau, Maria Dolores; Gonzalez-Diaz, Rocio; Jimenez, Maria Jose; Real, Pedro; Silva, Beatriz

    2001-01-01

    We use homological perturbation machinery specific for the algebra category [P. Real. Homological Perturbation Theory and Associativity. Homology, Homotopy and Applications vol. 2, n. 5 (2000) 51-88] to give an algorithm for computing the differential structure of a small 1--homological model for commutative differential graded algebras (briefly, CDGAs). The complexity of the procedure is studied and a computer package in Mathematica is described for determining such models.

  13. Overview of parallel algorithms in numerical linear algebra

    Energy Technology Data Exchange (ETDEWEB)

    Sameh, A.

    1983-01-01

    The author gives a brief survey of the development of multiprocessor algorithms for: (i) the direct solution of linear systems, (ii) the algebraic eigenvalue problem, and (iii) the direct and iterative methods for solving the finite-difference or finite-element linear systems of equations arising from the discretization of linear partial differential equations. 66 references.

  14. An Algorithm for the Decomposition of Semisimple Lie Algebras

    NARCIS (Netherlands)

    Graaf, W.A. de

    2001-01-01

    We consider the problem of decomposing a semisimple Lie algebra dened over a eld of characteristic zero as a direct sum of its simple ideals The method is based on the decomposition of the action of a Cartan subalgebra An implementation of the algorithm in the system ELIAS is discussed at the end of

  15. HDL IMPLEMENTATION OF ALGEBRAIC SOFT DECISION ALGORITHM FOR RS CODES

    OpenAIRE

    M. Revathy; Saravanan, R.

    2013-01-01

    Reed Solomon (RS) codes are widely used to detect and correct data errors in transmission andstorage systems. Hence it is used in many digital communication and storage devices. In existing systemReformulated inversion less Burst error correcting (RiBC) algorithm is used. But it lacks in speed,throughput & area. To overcome this Algebraic Soft Decision (ASD) algorithm is proposed. This Proposedalgorithm is based on Unified VLSI architecture for correcting burst errors as well as random errors...

  16. Algorithmic Algebraic Combinatorics and Gröbner Bases

    CERN Document Server

    Klin, Mikhail; Jurisic, Aleksandar

    2009-01-01

    This collection of tutorial and research papers introduces readers to diverse areas of modern pure and applied algebraic combinatorics and finite geometries with a special emphasis on algorithmic aspects and the use of the theory of Grobner bases. Topics covered include coherent configurations, association schemes, permutation groups, Latin squares, the Jacobian conjecture, mathematical chemistry, extremal combinatorics, coding theory, designs, etc. Special attention is paid to the description of innovative practical algorithms and their implementation in software packages such as GAP and MAGM

  17. MODEL IDENTIFICATION AND COMPUTER ALGEBRA.

    Science.gov (United States)

    Bollen, Kenneth A; Bauldry, Shawn

    2010-10-01

    Multiequation models that contain observed or latent variables are common in the social sciences. To determine whether unique parameter values exist for such models, one needs to assess model identification. In practice analysts rely on empirical checks that evaluate the singularity of the information matrix evaluated at sample estimates of parameters. The discrepancy between estimates and population values, the limitations of numerical assessments of ranks, and the difference between local and global identification make this practice less than perfect. In this paper we outline how to use computer algebra systems (CAS) to determine the local and global identification of multiequation models with or without latent variables. We demonstrate a symbolic CAS approach to local identification and develop a CAS approach to obtain explicit algebraic solutions for each of the model parameters. We illustrate the procedures with several examples, including a new proof of the identification of a model for handling missing data using auxiliary variables. We present an identification procedure for Structural Equation Models that makes use of CAS and that is a useful complement to current methods. PMID:21769158

  18. Optimizing algebraic petri net model checking by slicing

    OpenAIRE

    Khan, Yasir Imtiaz; Risoldi, Matteo

    2013-01-01

    High-level Petri nets make models more concise and read- able as compared to low-level Petri nets. However, usual verification techniques such as state space analysis remain an open challenge for both because of state space explosion. The contribution of this paper is to propose an approach for property based reduction of the state space of Algebraic Petri nets (a variant of high-level Petri nets). To achieve the objective, we propose a slicing algorithm for Algebraic Petri ...

  19. Matrix algebra for linear models

    CERN Document Server

    Gruber, Marvin H J

    2013-01-01

    Matrix methods have evolved from a tool for expressing statistical problems to an indispensable part of the development, understanding, and use of various types of complex statistical analyses. This evolution has made matrix methods a vital part of statistical education. Traditionally, matrix methods are taught in courses on everything from regression analysis to stochastic processes, thus creating a fractured view of the topic. Matrix Algebra for Linear Models offers readers a unique, unified view of matrix analysis theory (where and when necessary), methods, and their applications. Written f

  20. Bethe algebra of Gaudin model, Calogero-Moser space and Cherednik algebra

    OpenAIRE

    Mukhin, E.; Tarasov, V.; Varchenko, A.

    2009-01-01

    We identify the Bethe algebra of the Gaudin model associated to gl(N) acting on a suitable representation with the center of the rational Cherednik algebra and with the algebra of regular functions on the Calogero-Moser space.

  1. A Review of Algebraic Link Analysis Algorithms

    Directory of Open Access Journals (Sweden)

    Mini Singh Ahuja

    2012-08-01

    Full Text Available The World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them by using hyperlinks. Navigation is the process through which the users can achieve their purposes in using Web site, such as to find the information that they need or to complete the transactions that they want to do. Web mining is the application of data mining techniques to extract knowledge from Web data, where at least one of structure (hyperlink or usage (Web log data is used in the mining process (with or without other types of Web data. In this paper we have briefly discussed the web mining technique with major stress to the link analysis algorithms.

  2. Algorithm for solving polynomial algebraic Riccati equations and its application

    Czech Academy of Sciences Publication Activity Database

    Augusta, Petr; Augustová, Petra

    2012-01-01

    Roč. 1, č. 4 (2012), s. 237-242. ISSN 2223-7038 R&D Projects: GA ČR GPP103/12/P494 Institutional support: RVO:67985556 Keywords : Numerical algorithms * algebraic Riccati equation * spatially distributed systems * optimal control Subject RIV: BC - Control Systems Theory http://lib.physcon.ru/doc?id=8b4876d6a57d

  3. Effective Algorithms for Parametrizing Linear Control Systems over Ore Algebras

    OpenAIRE

    Chyzak, Frédéric; Quadrat, Alban; Robertz, Daniel

    2004-01-01

    In this paper, we study linear control systems over Ore algebras. Within this mathematical framework, we can simultaneously deal with different classes of linear control systems such as time-varying systems of ordinary differential equations (ODEs), differential time-delay systems, underdetermined systems of partial differential equations (PDEs), multidimensional discrete systems, multidimensional convolutional codes etc. We give effective algorithms which check whether or not a linear contro...

  4. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy

    Science.gov (United States)

    Afsharpour, H.; Landry, G.; D'Amours, M.; Enger, S.; Reniers, B.; Poon, E.; Carrier, J.-F.; Verhaegen, F.; Beaulieu, L.

    2012-06-01

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

  5. An explicit algebraic reduced order algorithm for lithium ion cell voltage prediction

    Science.gov (United States)

    Senthil Kumar, V.; Gambhire, Priya; Hariharan, Krishnan S.; Khandelwal, Ashish; Kolake, Subramanya Mayya; Oh, Dukjin; Doo, Seokgwang

    2014-02-01

    The detailed isothermal electrochemical model for a lithium ion cell has ten coupled partial differential equations to describe the cell behavior. In an earlier publication [Journal of Power Sources, 222, 426 (2013)], a reduced order model (ROM) was developed by reducing the detailed model to a set of five linear ordinary differential equations and nonlinear algebraic expressions, using uniform reaction rate, volume averaging and profile based approximations. An arbitrary current profile, involving charge, rest and discharge, is broken down into constant current and linearly varying current periods. The linearly varying current period results are generic, since it includes the constant current period results as well. Hence, the linear ordinary differential equations in ROM are solved for a linearly varying current period and an explicit algebraic algorithm is developed for lithium ion cell voltage prediction. While the existing battery management system (BMS) algorithms are equivalent circuit based and ordinary differential equations, the proposed algorithm is an explicit algebraic algorithm. These results are useful to develop a BMS algorithm for on-board applications in electric or hybrid vehicles, smart phones etc. This algorithm is simple enough for a spread-sheet implementation and is useful for rapid analysis of laboratory data.

  6. ALGEBRAIC GENERALIZATION OF THE CASH FLOW STATEMENT: REFLECTIONS BY MEANS OF AN ALGEBRAIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    José Roberto Kassai

    2012-09-01

    Full Text Available Starting on January 1, 2008 it became mandatory for all Brazilian public companies and private companies with net worth greater than two million reais (about one million dollars as of this writing to publish a cash flow statement (CFS as part of their financial statements, making this statement another important source of information for investors. This article proposes an algebraic generalization for the CFS. Working papers can help fill in a gap in teaching about cash flow statements and produce an indirect method and a direct method, side by side with their equivalence highlighted, in a single matrix by means of algebraic algorithms. This study is normative in nature and stresses the transversal relationship between accounting and mathematics, showing that accounting reports and their structures can be seen as matrices and be subjected to algebraic deductions about the events recorded by double entries. As a result, we demonstrate a mathematical algorithm with matrices and submatrices and a script in the format of working papers, compatible with the normative orientations of the Federal Accounting Council (CFS and Brazilian legislation, permitting formulation of clear, reliable and effective cash flow statements.

  7. An algebraic model of software evolution

    OpenAIRE

    Keller, Benjamin J.d

    1990-01-01

    A model of the software evolution process, called the Abstraction Refinement Model, is described which builds on the algebraic influence of the Laws of Programming and the transformational Draco Paradigm. The result is an algebraic structure consisting of the states of the software product (system descriptions) ordered by a relation of relative correctness with transformations defined between the system descriptions. This structure is interpreted as the software evolution space, ...

  8. An Algorithm to Solve algebraic Riccati Equations with Polynomials

    Czech Academy of Sciences Publication Activity Database

    Augusta, Petr

    Szczecin: West Pomeranian University of Technology, 2012, s. 409-414. ISBN 978-1-4673-2123-5. [The 17th International Conference on Methods and Models in Automation and Robotics . Międzyzdroje (PL), 27.08.2012-30.08.2012] R&D Projects: GA ČR GPP103/12/P494 Institutional support: RVO:67985556 Keywords : algebraic Riccati equations * spatially distributed systems * Fourier transforms Subject RIV: BC - Control Systems Theory

  9. New Algebraic Soft Decision Decoding Algorithm for Reed-Solomon Code

    OpenAIRE

    Zhu, Yuan; Tang, Siyun

    2014-01-01

    In this paper, a new algebraic soft-decision decoding algorithm for Reed-Solomon code is presented. It is based on rational interpolation and the interpolation points are constructed by Berlekamp-Messay algorithm. Unlike the traditional K{\\"o}tter-Vardy algorithm, new algorithm needs interpolation for two smaller multiplicity matrixes, due to the corresponding factorization algorithm for re-constructing codewords.

  10. Advanced computer algebra algorithms for the expansion of Feynman integrals

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, Jakob; Round, Mark; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2012-10-15

    Two-point Feynman parameter integrals, with at most one mass and containing local operator insertions in 4+{epsilon}-dimensional Minkowski space, can be transformed to multi-integrals or multi-sums over hyperexponential and/or hypergeometric functions depending on a discrete parameter n. Given such a specific representation, we utilize an enhanced version of the multivariate Almkvist-Zeilberger algorithm (for multi-integrals) and a common summation framework of the holonomic and difference field approach (for multi-sums) to calculate recurrence relations in n. Finally, solving the recurrence we can decide efficiently if the first coefficients of the Laurent series expansion of a given Feynman integral can be expressed in terms of indefinite nested sums and products; if yes, the all n solution is returned in compact representations, i.e., no algebraic relations exist among the occurring sums and products.

  11. ADAM: Analysis of Discrete Models of Biological Systems Using Computer Algebra

    CERN Document Server

    Hinkelmann, Franziska; Guang, Bonny; McNeill, Rustin; Blekherman, Grigoriy; Veliz-Cuba, Alan; Laubenbacher, Reinhard

    2010-01-01

    Motivation: Many biological systems are modeled qualitatively with discrete models, such as probabilistic Boolean networks, logical models, bounded Petri nets, and agent-based models. Simulation is a common practice for analyzing discrete models, but many systems are far too large to capture all the relevant dynamical features through simulation alone. Results: We convert discrete models into algebraic models and apply tools from computational algebra to analyze their dynamics. The key feature of biological systems that is exploited by our algorithms is their sparsity: while the number of nodes in a biological network may be quite large, each node is affected only by a small number of other nodes. In our experience with models arising in systems biology and random models, this structure leads to fast computations when using algebraic models, and thus efficient analysis. Availability: All algorithms and methods are available in our package Analysis of Dynamic Algebraic Models (ADAM), a user friendly web-interf...

  12. Quantum corrections of (fuzzy) spacetimes from a supersymmetric reduced model with Filippov 3-algebra

    OpenAIRE

    Tomino, Dan

    2010-01-01

    1-loop vacuum energies of (fuzzy) spacetimes from a supersymmetric reduced model with Filippov 3-algebra are discussed. A_{2,2} algebra, Nambu-Poisson algebra in flat spacetime, and a Lorentzian 3-algebra are examined as 3-algebras.

  13. A process algebra model of QED

    Science.gov (United States)

    Sulis, William

    2016-03-01

    The process algebra approach to quantum mechanics posits a finite, discrete, determinate ontology of primitive events which are generated by processes (in the sense of Whitehead). In this ontology, primitive events serve as elements of an emergent space-time and of emergent fundamental particles and fields. Each process generates a set of primitive elements, using only local information, causally propagated as a discrete wave, forming a causal space termed a causal tapestry. Each causal tapestry forms a discrete and finite sampling of an emergent causal manifold (space-time) M and emergent wave function. Interactions between processes are described by a process algebra which possesses 8 commutative operations (sums and products) together with a non-commutative concatenation operator (transitions). The process algebra possesses a representation via nondeterministic combinatorial games. The process algebra connects to quantum mechanics through the set valued process and configuration space covering maps, which associate each causal tapestry with sets of wave functions over M. Probabilities emerge from interactions between processes. The process algebra model has been shown to reproduce many features of the theory of non-relativistic scalar particles to a high degree of accuracy, without paradox or divergences. This paper extends the approach to a semi-classical form of quantum electrodynamics.

  14. Ideals, varieties, and algorithms an introduction to computational algebraic geometry and commutative algebra

    CERN Document Server

    Cox, David A; O'Shea, Donal

    2015-01-01

    This text covers topics in algebraic geometry and commutative algebra with a strong perspective toward practical and computational aspects. The first four chapters form the core of the book. A comprehensive chart in the preface illustrates a variety of ways to proceed with the material once these chapters are covered. In addition to the fundamentals of algebraic geometry—the elimination theorem, the extension theorem, the closure theorem, and the Nullstellensatz—this new edition incorporates several substantial changes, all of which are listed in the Preface. The largest revision incorporates a new chapter (ten), which presents some of the essentials of progress made over the last decades in computing Gröbner bases. The book also includes current computer algebra material in Appendix C and updated independent projects (Appendix D). The book may serve as a first or second course in undergraduate abstract algebra and, with some supplementation perhaps, for beginning graduate level courses in algebraic geom...

  15. AR quivers,exceptional sequences and algorithms in derived Hall algebras

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Consider the canonical isomorphism between the positive part U+ of the quantum group Uq(g) and the Hall algebra H(Λ),where the semisimple Lie algebra g and the finite-dimensional hereditary algebra Λ share a Dynkin diagram.Chen and Xiao have given two algorithms to decompose the root vectors into linear combinations of monomials of Chevalley generators of U+,respectively induced by the braid group action on the exceptional sequences of Λ-modules and the structure of the Auslander-Reiten quiver of Λ.In this paper,we obtain the corresponding algorithms for the derived Hall algebra DH(Λ),which was introduced by Toen.We show that both algorithms are applicable to the lattice algebra and Heisenberg double in the sense of Kapranov.All the new recursive formulae have the same flavor with the quantum Serre relations.

  16. Sigma-models and Homotopy Algebras

    CERN Document Server

    Zeitlin, Anton M

    2015-01-01

    We review the relation between homotopy algebras of conformal field theory and geometric structures arising in sigma models. In particular we formulate conformal invariance conditions, which in the quasi-classical limit are Einstein equations with extra fields, as generalized Maurer-Cartan equations.

  17. Fusion algebras of logarithmic minimal models

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Joergen; Pearce, Paul A [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)

    2007-11-09

    We present explicit conjectures for the chiral fusion algebras of the logarithmic minimal models LM(p,p') considering Virasoro representations with no enlarged or extended symmetry algebra. The generators of fusion are countably infinite in number but the ensuing fusion rules are quasi-rational in the sense that the fusion of a finite number of representations decomposes into a finite direct sum of representations. The fusion rules are commutative, associative and exhibit an sl(2) structure but require so-called Kac representations which are typically reducible yet indecomposable representations of rank 1. In particular, the identity of the fundamental fusion algebra p {ne} 1 is a reducible yet indecomposable Kac representation of rank 1. We make detailed comparisons of our fusion rules with the results of Gaberdiel and Kausch for p = 1 and with Eberle and Flohr for (p, p') = (2, 5) corresponding to the logarithmic Yang-Lee model. In the latter case, we confirm the appearance of indecomposable representations of rank 3. We also find that closure of a fundamental fusion algebra is achieved without the introduction of indecomposable representations of rank higher than 3. The conjectured fusion rules are supported, within our lattice approach, by extensive numerical studies of the associated integrable lattice models. Details of our lattice findings and numerical results will be presented elsewhere. The agreement of our fusion rules with the previous fusion rules lends considerable support for the identification of the logarithmic minimal models LM(p,p') with the augmented c{sub p,p'} (minimal) models defined algebraically.

  18. An algebraic approach to the Hubbard model

    CERN Document Server

    de Leeuw, Marius

    2015-01-01

    We study the algebraic structure of an integrable Hubbard-Shastry type lattice model associated with the centrally extended su(2|2) superalgebra. This superalgebra underlies Beisert's AdS/CFT worldsheet R-matrix and Shastry's R-matrix. The considered model specializes to the one-dimensional Hubbard model in a certain limit. We demonstrate that Yangian symmetries of the R-matrix specialize to the Yangian symmetry of the Hubbard model found by Korepin and Uglov. Moreover, we show that the Hubbard model Hamiltonian has an algebraic interpretation as the so-called secret symmetry. We also discuss Yangian symmetries of the A and B models introduced by Frolov and Quinn.

  19. Phase transitions in algebraic cluster models

    International Nuclear Information System (INIS)

    We study the phase transitions of two algebraic cluster models, which have similar interactions, but differ from each other in their model spaces. The semimicroscopical model incorporates the Pauli exclusion principle, while the phenomenological one does not. The appearance of the quasidynamical SU(3) symmetry is also investigated in the presence of an explicitly symmetry-breaking interaction. Examples of binary cluster configurations with two, one, or zero closed-shell clusters are studied

  20. Boundary algebras and Kac modules for logarithmic minimal models

    Science.gov (United States)

    Morin-Duchesne, Alexi; Rasmussen, Jørgen; Ridout, David

    2015-10-01

    Virasoro Kac modules were originally introduced indirectly as representations whose characters arise in the continuum scaling limits of certain transfer matrices in logarithmic minimal models, described using Temperley-Lieb algebras. The lattice transfer operators include seams on the boundary that use Wenzl-Jones projectors. If the projectors are singular, the original prescription is to select a subspace of the Temperley-Lieb modules on which the action of the transfer operators is non-singular. However, this prescription does not, in general, yield representations of the Temperley-Lieb algebras and the Virasoro Kac modules have remained largely unidentified. Here, we introduce the appropriate algebraic framework for the lattice analysis as a quotient of the one-boundary Temperley-Lieb algebra. The corresponding standard modules are introduced and examined using invariant bilinear forms and their Gram determinants. The structures of the Virasoro Kac modules are inferred from these results and are found to be given by finitely generated submodules of Feigin-Fuchs modules. Additional evidence for this identification is obtained by comparing the formalism of lattice fusion with the fusion rules of the Virasoro Kac modules. These are obtained, at the character level, in complete generality by applying a Verlinde-like formula and, at the module level, in many explicit examples by applying the Nahm-Gaberdiel-Kausch fusion algorithm.

  1. Algebra

    CERN Document Server

    Tabak, John

    2004-01-01

    Looking closely at algebra, its historical development, and its many useful applications, Algebra examines in detail the question of why this type of math is so important that it arose in different cultures at different times. The book also discusses the relationship between algebra and geometry, shows the progress of thought throughout the centuries, and offers biographical data on the key figures. Concise and comprehensive text accompanied by many illustrations presents the ideas and historical development of algebra, showcasing the relevance and evolution of this branch of mathematics.

  2. Clifford algebra-based spatio-temporal modelling and analysis for complex geo-simulation data

    Science.gov (United States)

    Luo, Wen; Yu, Zhaoyuan; Hu, Yong; Yuan, Linwang

    2013-10-01

    The spatio-temporal data simulating Ice-Land-Ocean interaction of Antarctic are used to demonstrate the Clifford algebra-based data model construction, spatio-temporal query and data analysis. The results suggest that Clifford algebra provides a powerful mathematical tool for the whole modelling and analysis chains for complex geo-simulation data. It can also help implement spatio-temporal analysis algorithms more clearly and simply.

  3. The impact of hierarchical memory systems on linear algebra algorithm design

    Energy Technology Data Exchange (ETDEWEB)

    Gallivan, K.; Jalby, W.; Meier, U.; Sameh, A.

    1987-09-14

    Performing an extremely detailed performance optimization analysis is counterproductive when the concern is performance behavior on a class of architecture, since general trends are obscured by the overwhelming number of machine-specific considerations required. Instead, in this paper, a methodology is used which identifies the effects of a hierarchical memory system on the performance of linear algebra algorithms on multivector processors; provides a means of producing a set of algorithm parameters, i.e., blocksizes, as functions of system parameters which yield near-optimal performance; and provides guidelines for algorithm designers which reduce the influence of the hierarchical memory system on algorithm performance to negligible levels and thereby allow them to concentrate on machine-specific optimizations. The remainder of this paper comprises five major discussions. First, the methodology and the attendant architectural model are discussed. Next, an analysis of the basic BLAS3 matrix-matrix primitive is presented. This is followed by a discussion of three block algorithms: a block LU decomposition, a block LDL/sup T/ decomposition and a block Gram-Schmidt algorithm. 22 refs., 9 figs.

  4. MODEL IDENTIFICATION AND COMPUTER ALGEBRA

    OpenAIRE

    Bollen, Kenneth A.; Bauldry, Shawn

    2010-01-01

    Multiequation models that contain observed or latent variables are common in the social sciences. To determine whether unique parameter values exist for such models, one needs to assess model identification. In practice analysts rely on empirical checks that evaluate the singularity of the information matrix evaluated at sample estimates of parameters. The discrepancy between estimates and population values, the limitations of numerical assessments of ranks, and the difference between local a...

  5. Algebraic analysis of a model of two-dimensional gravity

    CERN Document Server

    Frolov, A M; Kuzmin, S V

    2009-01-01

    An algebraic analysis of the Hamiltonian formulation of the model two-dimensional gravity is performed. The crucial fact is an exact coincidence of the Poisson brackets algebra of the secondary constraints of this Hamiltonian formulation with the SO(2,1)-algebra. The eigenvectors of the canonical Hamiltonian $H_{c}$ are obtained and explicitly written in closed form.

  6. Graph model of the Heisenberg-Weyl algebra

    OpenAIRE

    Blasiak, P.; Horzela, A.; Duchamp, G. H. E.; Penson, K. A.; Solomon, A. I.

    2007-01-01

    We consider an algebraic formulation of Quantum Theory and develop a combinatorial model of the Heisenberg-Weyl algebra structure. It is shown that by lifting this structure to the richer algebra of graph operator calculus, we gain a simple interpretation involving, for example, the natural composition of graphs. This provides a deeper insight into the algebraic structure of Quantum Theory and sheds light on the intrinsic combinatorial underpinning of its abstract formalism.

  7. Graph model of the Heisenberg-Weyl algebra

    International Nuclear Information System (INIS)

    We consider an algebraic formulation of Quantum Theory and develop a combinatorial model of the Heisenberg-Weyl algebra structure. It is shown that by lifting this structure to the richer algebra of graph operator calculus, we gain a simple interpretation involving, for example, the natural composition of graphs. This provides a deeper insight into the algebraic structure of Quantum Theory and sheds light on the intrinsic combinatorial underpinning of its abstract formalism.

  8. Phase transitions in algebraic cluster models

    International Nuclear Information System (INIS)

    Complete text of publication follows. There has been much interest recently in phase transitions in various nuclear systems. The phases are defined as (local) minima of the potential energy surface (PES) defined in terms of parameters characterizing the nuclear system. Phase transitions occur when some relevant parameter is changed gradually and the system moves from one phase to another one. In the analysis of such systems the key questions are the number of phases and the order of phase transition between them. Algebraic nuclear structure models are especially interesting from the phase transition point of view, because the different phases may be characterized by different symmetries of the system. Much work has been done recently on models based on the interacting boson approximation (IBA). In these studies the potential energy surface is constructed from the algebraic Hamiltonian by its geometric mapping using the coherent state formalism. Inspired by these studies we performed a similar analysis of a family of algebraic cluster models based on the semimicroscopic algebraic cluster model (SACM). This model has two dynamical symmetries: the SU(3) and SO(4) limits are believed to correspond to vibration around a spherical equilibrium shape and static dipole deformation, respectively. The semimicroscopic nature of this model is reflected by the fact that a fully antisymmetrized microscopic model space is combined with a phenomenologic Hamiltonian that describes excitations of the (typically) two-cluster system. The microscopic model space is necessary to take into account the Pauli exclusion principle acting between the nucleons of the closely interacting clusters. In practice this means that the number of excitation quanta in the relative motion of the clusters has to exceed a certain number n0 characterizing the system. This is clearly a novelty with respect to other algebraic models, and it complicates the formalism considerably. We thus introduced as a

  9. Algebra

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Through most of Greek history, mathematicians concentrated on geometry, although Euclid considered the theory of numbers. The Greek mathematician Diophantus (3rd century),however, presented problems that had to be solved by what we would today call algebra. His book is thus the first algebra text.

  10. Algorithmic Differentiation of Linear Algebra Functions with Application in Optimum Experimental Design (Extended Version)

    OpenAIRE

    Walter, S. F.; Lehmann, L

    2010-01-01

    We derive algorithms for higher order derivative computation of the rectangular $QR$ and eigenvalue decomposition of symmetric matrices with distinct eigenvalues in the forward and reverse mode of algorithmic differentiation (AD) using univariate Taylor propagation of matrices (UTPM). Linear algebra functions are regarded as elementary functions and not as algorithms. The presented algorithms are implemented in the BSD licensed AD tool \\texttt{ALGOPY}. Numerical tests show that the UTPM algor...

  11. Quantum spin models and extended conformal algebras

    CERN Document Server

    Honecker, A

    1995-01-01

    First, an algebraic criterion for integrability is discussed -the so-called `superintegrability'- and some results on the classification of superintegrable quantum spin Hamiltonians based on sl(2) are obtained. Next, the massive phases of the Z_n-chiral Potts quantum spin chain (a model that violates parity) are studied in detail. It is shown that the excitation spectrum of the massive high-temperature phase can be explained in terms of n-1 fundamental quasiparticles. We compute correlation functions from a perturbative and numerical evaluation of the groundstate for the Z_3-chain. In addition to an exponential decay we observe an oscillating contribution. The oscillation length seems to be related to the asymmetry of the dispersion relations. We show that this relation is exact at special values of the parameters for general Z_n using a form factor expansion. Finally, we discuss several aspects of extended conformal algebras (W-algebras). We observe an analogy between boundary conditions for Z_n-spin chains ...

  12. Algebra

    CERN Document Server

    Flanders, Harley

    1975-01-01

    Algebra presents the essentials of algebra with some applications. The emphasis is on practical skills, problem solving, and computational techniques. Topics covered range from equations and inequalities to functions and graphs, polynomial and rational functions, and exponentials and logarithms. Trigonometric functions and complex numbers are also considered, together with exponentials and logarithms.Comprised of eight chapters, this book begins with a discussion on the fundamentals of algebra, each topic explained, illustrated, and accompanied by an ample set of exercises. The proper use of a

  13. Algebraic model theory for languages without equality

    OpenAIRE

    Elgueta Montó, Raimon

    1994-01-01

    In our opinion, it is fair to distinguish two separate branches in the origins of model theory. The first one, the model theory of first-order logic, can be traced back to the pioneering work of L. Lowenheim, T. Skolem, K. Gödel, A. Tarski and A.I. MaI 'cev, published before the mid 30's. This branch was put forward during the 40s' and 50s’ by several authors, including A. Tarski, L. Henkin, A. Robinson, J. Los. Their contribution, however, was rather influenced by modern algebra, a disciplin...

  14. A Groebner-bases algorithm for the computation of the cohomology of Lie (super) algebras

    OpenAIRE

    -Alizadeh, Benyamin M.; Merker, Joel; Sabzevari, Masoud

    2011-01-01

    We present an effective algorithm for computing the standard cohomology spaces of finitely generated Lie (super) algebras over a commutative field K of characteristic zero. In order to reach explicit representatives of some generators of the quotient space Z^k/B^k of cocycles Z^k modulo coboundaries B^k, we apply Groebner bases techniques (in the appropriate linear setting) and take advantage of their strength. Moreover, when the considered Lie (super) algebras enjoy a grading -- a case which...

  15. Multi-Matrix Models and Noncommutative Frobenius Algebras Obtained from Symmetric Groups and Brauer Algebras

    Science.gov (United States)

    Kimura, Yusuke

    2015-07-01

    It has been understood that correlation functions of multi-trace operators in SYM can be neatly computed using the group algebra of symmetric groups or walled Brauer algebras. On the other hand, such algebras have been known to construct 2D topological field theories (TFTs). After reviewing the construction of 2D TFTs based on symmetric groups, we construct 2D TFTs based on walled Brauer algebras. In the construction, the introduction of a dual basis manifests a similarity between the two theories. We next construct a class of 2D field theories whose physical operators have the same symmetry as multi-trace operators constructed from some matrices. Such field theories correspond to non-commutative Frobenius algebras. A matrix structure arises as a consequence of the noncommutativity. Correlation functions of the Gaussian complex multi-matrix models can be translated into correlation functions of the two-dimensional field theories.

  16. Matrix Algebra for Quantum Search Algorithm: Non Unitary Symmetries and Entanglement

    Science.gov (United States)

    Ellinas, Demosthenes; Konstandakis, Christos

    2011-10-01

    An algebraic reformulation of the quantum search algorithm associated to a k-valued oracle function, is introduced in terms of the so called oracle matrix algebra, by means of which a Bloch sphere like description of search is obtained. A parametric family of symmetric completely positive trace preserving (CPTP) maps, that formalize the presence of quantum noise but preserves the complexity of the algorithm, is determined. Dimensional reduction of representations of oracle Lie algebra is introduced in order to determine the reduced density matrix of subsets of qubits in database. The L1 vector-induced norm of reduced density matrix is employed to define an index function for the quantum entanglement between database qubits, in the presence of non invariant noise CPTP maps. Analytic investigations provide a causal relation between entanglement and fidelity of the algorithm, which is controlled by quantum noise parameter.

  17. Energy footprint of advanced dense numerical linear algebra using tile algorithms on multicore architectures

    KAUST Repository

    Dongarra, Jack

    2012-11-01

    We propose to study the impact on the energy footprint of two advanced algorithmic strategies in the context of high performance dense linear algebra libraries: (1) mixed precision algorithms with iterative refinement allow to run at the peak performance of single precision floating-point arithmetic while achieving double precision accuracy and (2) tree reduction technique exposes more parallelism when factorizing tall and skinny matrices for solving over determined systems of linear equations or calculating the singular value decomposition. Integrated within the PLASMA library using tile algorithms, which will eventually supersede the block algorithms from LAPACK, both strategies further excel in performance in the presence of a dynamic task scheduler while targeting multicore architecture. Energy consumption measurements are reported along with parallel performance numbers on a dual-socket quad-core Intel Xeon as well as a quad-socket quad-core Intel Sandy Bridge chip, both providing component-based energy monitoring at all levels of the system, through the Power Pack framework and the Running Average Power Limit model, respectively. © 2012 IEEE.

  18. Applications Of Algebraic Image Operators To Model-Based Vision

    Science.gov (United States)

    Lerner, Bao-Ting; Morelli, Michael V.; Thomas, Hans J.

    1989-03-01

    This paper extends our previous research on a highly structured and compact algebraic representation of grey-level images. Addition and multiplication are defined for the set of all grey-level images, which can then be described as polynomials of two variables. Utilizing this new algebraic structure, we have devised an innovative, efficient edge detection scheme.We have developed a robust method for linear feature extraction by combining the techniques of a Hough transform and a line follower with this new edge detection scheme. The major advantage of this feature extractor is its general, object-independent nature. Target attributes, such as line segment lengths, intersections, angles of intersection, and endpoints are derived by the feature extraction algorithm and employed during model matching. The feature extractor and model matcher are being incorporated into a distributed robot control system. Model matching is accomplished using both top-down and bottom-up processing: a priori sensor and world model information are used to constrain the search of the image space for features, while extracted image information is used to update the model.

  19. A new algorithm for differential-algebraic equations based on HIDM

    International Nuclear Information System (INIS)

    A new algorithm is proposed to solve differential-algebraic equations. The algorithm is an extension of the algorithm of general purpose HIDM (higher order implicit difference method). A computer program named HDMTDV and based on the new algorithm is constructed and its high performance is proved numerically through several numerical computations, including index-2 problem of differential-algebraic equations and connected rigid pendulum equations. The new algorithm is also secular error free when applied to dissipationless dynamical systems. This nature is demonstrated numerically by computation of the Kepler motion. The new code can solve the initial value problem O = L { φ(x), [dφ(x)]/dx, [d2φ(x)]/dx2, x }, where L and φ are vectors of length N. The values of first or second derivatives of φ(x) are not always necessary in the equations. (author)

  20. Isovectorial pairing in solvable and algebraic models

    International Nuclear Information System (INIS)

    Schematic interactions are useful to gain some insight in the behavior of very complicated systems such as the atomic nuclei. Prototypical examples are, in this context, the pairing interaction and the quadrupole interaction of the Elliot model. In this contribution the interplay between isovectorial pairing, spin-orbit, and quadrupole terms in a harmonic oscillator shell (the so-called pairing-plus-quadrupole model) is studied by algebraic methods. The ability of this model to provide a realistic description of N = Z even-even nuclei in the fp-shell is illustrated with 44Ti. Our calculations which derive from schematic and simple terms confirm earlier conclusions obtained by using realistic interactions: the SU(3) symmetry of the quadrupole term is broken mainly by the spin-orbit term, but the energies depends strongly on pairing.

  1. Symmetries of faces models and the double triangle algebra

    CERN Document Server

    Trinchero, R

    2005-01-01

    Symmetries of trigonometric integrable two dimensional statistical face models are considered. The corresponding symmetry operators on the Hilbert space of states of the quantum version of these models define a weak *-Hopf algebra isomorphic to the Ocneanu double triangle algebra(DTA).

  2. Preparing Secondary Mathematics Teachers: A Focus on Modeling in Algebra

    Science.gov (United States)

    Jung, Hyunyi; Mintos, Alexia; Newton, Jill

    2015-01-01

    This study addressed the opportunities to learn (OTL) modeling in algebra provided to secondary mathematics pre-service teachers (PSTs). To investigate these OTL, we interviewed five instructors of required mathematics and mathematics education courses that had the potential to include opportunities for PSTs to learn algebra at three universities.…

  3. Real-time dynamics simulation of the Cassini spacecraft using DARTS. Part 1: Functional capabilities and the spatial algebra algorithm

    Science.gov (United States)

    Jain, A.; Man, G. K.

    1993-01-01

    This paper describes the Dynamics Algorithms for Real-Time Simulation (DARTS) real-time hardware-in-the-loop dynamics simulator for the National Aeronautics and Space Administration's Cassini spacecraft. The spacecraft model consists of a central flexible body with a number of articulated rigid-body appendages. The demanding performance requirements from the spacecraft control system require the use of a high fidelity simulator for control system design and testing. The DARTS algorithm provides a new algorithmic and hardware approach to the solution of this hardware-in-the-loop simulation problem. It is based upon the efficient spatial algebra dynamics for flexible multibody systems. A parallel and vectorized version of this algorithm is implemented on a low-cost, multiprocessor computer to meet the simulation timing requirements.

  4. An efficient algorithm for the contig ordering problem under algebraic rearrangement distance.

    Science.gov (United States)

    Lu, Chin Lung

    2015-11-01

    Assembling a genome from short reads currently obtained by next-generation sequencing techniques often results in a collection of contigs, whose relative position and orientation along the genome being sequenced are unknown. Given two sets of contigs, the contig ordering problem is to order and orient the contigs in each set such that the genome rearrangement distance between the resulting sets of ordered and oriented contigs is minimized. In this article, we utilize the permutation groups in algebra to propose a near-linear time algorithm for solving the contig ordering problem under algebraic rearrangement distance, where the algebraic rearrangement distance between two sets of ordered and oriented contigs is the minimum weight of applicable rearrangement operations required to transform one set into the other. PMID:26247343

  5. Action Algebras and Model Algebras in Denotational Semantics

    Science.gov (United States)

    Guedes, Luiz Carlos Castro; Haeusler, Edward Hermann

    This article describes some results concerning the conceptual separation of model dependent and language inherent aspects in a denotational semantics of a programming language. Before going into the technical explanation, the authors wish to relate a story that illustrates how correctly and precisely posed questions can influence the direction of research. By means of his questions, Professor Mosses aided the PhD research of one of the authors of this article and taught the other, who at the time was a novice supervisor, the real meaning of careful PhD supervision. The student’s research had been partially developed towards the implementation of programming languages through denotational semantics specification, and the student had developed a prototype [12] that compared relatively well to some industrial compilers of the PASCAL language. During a visit to the BRICS lab in Aarhus, the student’s supervisor gave Professor Mosses a draft of an article describing the prototype and its implementation experiments. The next day, Professor Mosses asked the supervisor, “Why is the generated code so efficient when compared to that generated by an industrial compiler?” and “You claim that the efficiency is simply a consequence of the Object- Orientation mechanisms used by the prototype programming language (C++); this should be better investigated. Pay more attention to the class of programs that might have this good comparison profile.” As a result of these aptly chosen questions and comments, the student and supervisor made great strides in the subsequent research; the advice provided by Professor Mosses made them perceive that the code generated for certain semantic domains was efficient because it mapped to the “right aspect” of the language semantics. (Certain functional types, used to represent mappings such as Stores and Environments, were pushed to the level of the object language (as in gcc). This had the side-effect of generating code for arrays in

  6. The development of an algebraic multigrid algorithm for symmetric positive definite linear systems

    Energy Technology Data Exchange (ETDEWEB)

    Vanek, P.; Mandel, J.; Brezina, M. [Univ. of Colorado, Denver, CO (United States)

    1996-12-31

    An algebraic multigrid algorithm for symmetric, positive definite linear systems is developed based on the concept of prolongation by smoothed aggregation. Coarse levels are generated automatically. We present a set of requirements motivated heuristically by a convergence theory. The algorithm then attempts to satisfy the requirements. Input to the method are the coefficient matrix and zero energy modes, which are determined from nodal coordinates and knowledge of the differential equation. Efficiency of the resulting algorithm is demonstrated by computational results on real world problems from solid elasticity, plate blending, and shells.

  7. Fermi resonance-algebraic model for molecular vibrational spectra

    Institute of Scientific and Technical Information of China (English)

    侯喜文; 董世海; 谢汨; 马中骐

    1999-01-01

    A Fermi resonance-algebraic model is proposed for molecular vibrations, where a U(2) algebra is used for describing the vibrations of each bond, and Fermi resonances between stretching and bending modes are taken into account. The model for a bent molecule XY2 and a molecule XY3 is successfully applied to fitting the recently observed vibrational spectrum of the water molecule and arsine (AsH3), respectively, and the results are compared with those of other models. Calculations show that algebraic approaches can be used as an effective method to describe molecular vibrations with small standard deviations.

  8. Modelling Software Evolution using Algebraic Graph Rewriting

    OpenAIRE

    Ciraci, Selim; Broek, van den, PR Peter; Avgeriou, P.; Zdun, U.; Borne, I

    2006-01-01

    We show how evolution requests can be formalized using algebraic graph rewriting. In particular, we present a way to convert the UML class diagrams to colored graphs. Since changes in software may effect the relation between the methods of classes, our colored graph representation also employs the relations in UML interaction diagrams. Then, we provide a set of algebraic graph rewrite rules that formalizes the changes that may be caused by an evolution request, using the pushout construction ...

  9. W-algebras and superalgebras from constrained WZW models

    International Nuclear Information System (INIS)

    A classification of W algebras and superalgebras arising in Abelian as well as non Abelian Toda theories is presented. Each model, obtained from a constrained WZW action, is related with an Sl(2) subalgebra (resp. OSp(1/2) superalgebra) of a simple Lie algebra (resp. superalgebra) G. However, the determination of an U(1)Y factor, commuting with Sl(2) (resp. OSp(1/2)), appears, when it exists, particularly useful to characterize the corresponding W algebra. The (super) conformal spin contents of each W (super)algebra is performed. The class of all the superconformal algebras (i.e. with conformal spins s≤2) is easily obtained as a byproduct of our general results. (author) 26 refs.; 21 tabs

  10. Algebra model and security analysis for cryptographic protocols

    Institute of Scientific and Technical Information of China (English)

    HUAI Jinpeng; LI Xianxian

    2004-01-01

    More and more cryptographic protocols have been used to achieve various security requirements of distributed systems in the open network environment. However cryptographic protocols are very difficult to design and analyze due to the complexity of the cryptographic protocol execution, and a large number of problems are unsolved that range from the theory framework to the concrete analysis technique. In this paper, we build a new algebra called cryptographic protocol algebra (CPA) for describing the message operations with many cryptographic primitives, and proposed a new algebra model for cryptographic protocols based on the CPA. In the model, expanding processes of the participant's knowledge on the protocol runs are characterized with some algebraic notions such as subalgebra, free generator and polynomial algebra, and attack processes are modeled with a new notion similar to that of the exact sequence used in homological algebra. Then we develope a mathematical approach to the cryptographic protocol security analysis. By using algebraic techniques, we have shown that for those cryptographic protocols with some symmetric properties, the execution space generated by an arbitrary number of participants may boil down to a smaller space generated by several honest participants and attackers. Furthermore we discuss the composability problem of cryptographic protocols and give a sufficient condition under which the protocol composed of two correct cryptographic protocols is still correct, and we finally offer a counterexample to show that the statement may not be true when the condition is not met.

  11. A note on probabilistic models over strings: the linear algebra approach.

    Science.gov (United States)

    Bouchard-Côté, Alexandre

    2013-12-01

    Probabilistic models over strings have played a key role in developing methods that take into consideration indels as phylogenetically informative events. There is an extensive literature on using automata and transducers on phylogenies to do inference on these probabilistic models, in which an important theoretical question is the complexity of computing the normalization of a class of string-valued graphical models. This question has been investigated using tools from combinatorics, dynamic programming, and graph theory, and has practical applications in Bayesian phylogenetics. In this work, we revisit this theoretical question from a different point of view, based on linear algebra. The main contribution is a set of results based on this linear algebra view that facilitate the analysis and design of inference algorithms on string-valued graphical models. As an illustration, we use this method to give a new elementary proof of a known result on the complexity of inference on the "TKF91" model, a well-known probabilistic model over strings. Compared to previous work, our proving method is easier to extend to other models, since it relies on a novel weak condition, triangular transducers, which is easy to establish in practice. The linear algebra view provides a concise way of describing transducer algorithms and their compositions, opens the possibility of transferring fast linear algebra libraries (for example, based on GPUs), as well as low rank matrix approximation methods, to string-valued inference problems. PMID:24135792

  12. Hyper-lattice algebraic model for data warehousing

    CERN Document Server

    Sen, Soumya; Chaki, Nabendu

    2016-01-01

    This book presents Hyper-lattice, a new algebraic model for partially ordered sets, and an alternative to lattice. The authors analyze some of the shortcomings of conventional lattice structure and propose a novel algebraic structure in the form of Hyper-lattice to overcome problems with lattice. They establish how Hyper-lattice supports dynamic insertion of elements in a partial order set with a partial hierarchy between the set members. The authors present the characteristics and the different properties, showing how propositions and lemmas formalize Hyper-lattice as a new algebraic structure.

  13. Quantum matrix algebra for the SU(n) WZNW model

    CERN Document Server

    Furlan, Paolo; Isaev, A P; Ogievetsky, O V; Pyatov, P N; Todorov, I T

    2003-01-01

    The zero modes of the chiral SU(n) WZNW model give rise to an intertwining quantum matrix algebra A generated by an n x n matrix a=(a^i_\\alpha) (with noncommuting entries) and by rational functions of n commuting elements q^{p_i}. We study a generalization of the Fock space (F) representation of A for generic q (q not a root of unity) and demonstrate that it gives rise to a model of the quantum universal enveloping algebra U_q(sl_n), each irreducible representation entering F with multiplicity 1. For an integer level k the complex parameter q is an even root of unity, q^h=-1 (h=k+n) and the algebra A has an ideal I_h such that the factor algebra A_h = A/I_h is finite dimensional.

  14. Category-theoretic models of algebraic computer systems

    Science.gov (United States)

    Kovalyov, S. P.

    2016-01-01

    A computer system is said to be algebraic if it contains nodes that implement unconventional computation paradigms based on universal algebra. A category-based approach to modeling such systems that provides a theoretical basis for mapping tasks to these systems' architecture is proposed. The construction of algebraic models of general-purpose computations involving conditional statements and overflow control is formally described by a reflector in an appropriate category of algebras. It is proved that this reflector takes the modulo ring whose operations are implemented in the conventional arithmetic processors to the Łukasiewicz logic matrix. Enrichments of the set of ring operations that form bases in the Łukasiewicz logic matrix are found.

  15. Observable algebras for the rational and trigonometric Euler-Calogero-Moser Models

    International Nuclear Information System (INIS)

    We construct polynomial Poisson algebras of observables for the classical Euler-Calogero-Moser (ECM) models. Their structure connects them to flavour-indexed non-linear W∞ algebras, albeit with qualitative differences. The conserved Hamiltonians and symmetry algebras derived in a previous work are subsets of these algebra. We define their linear, N →∞ limits, realizing W∞ type algebras coupled to current algebras. ((orig.))

  16. Model Checking Processes Specified In Join-Calculus Algebra

    Directory of Open Access Journals (Sweden)

    Sławomir Piotr Maludziński

    2014-01-01

    Full Text Available This article presents a model checking tool used to verify concurrent systems specified in join-calculus algebra. The temporal properties of systems under verification are expressed in CTL logic. Join-calculus algebra with its operational semantics defined by the chemical abstract machine serves as the basic method for the specification of concurrent systems and their synchronization mechanisms, and allows the examination of more complex systems.

  17. Model Checking Processes Specified In Join-Calculus Algebra

    OpenAIRE

    Sławomir Piotr Maludziński; Grzegorz Dobrowolski

    2014-01-01

    This article presents a model checking tool used to verify concurrent systems specified in join-calculus algebra. The temporal properties of systems under verification are expressed in CTL logic. Join-calculus algebra with its operational semantics defined by the chemical abstract machine serves as the basic method for the specification of concurrent systems and their synchronization mechanisms, and allows the examination of more complex systems.

  18. A Class of Parallel Tiled Linear Algebra Algorithms for Multicore Architectures

    CERN Document Server

    Buttari, Alfredo; Kurzak, Jakub; Dongarra, Jack

    2007-01-01

    As multicore systems continue to gain ground in the High Performance Computing world, linear algebra algorithms have to be re- formulated or new algorithms have to be developed in order to take ad- vantage of the architectural features on these new processors. Fine grain parallelism becomes a major requirement and introduces the necessity of loose synchronization in the parallel execution of an operation. This paper presents an algorithm for the Cholesky, LU and QR factorization where the operations can be represented as a sequence of small tasks that operate on square blocks of data. These tasks can be dynamically scheduled for execution based on the dependencies among them and on the availability of computational resources. This may result in an out of order execution of the tasks which will completely hide the presence of intrinsically sequential tasks in the factorization. Performance com- parisons are presented with the LAPACK algorithms where parallelism can only be exploited at the level of the BLAS op...

  19. Boundary algebras and Kac modules for logarithmic minimal models

    CERN Document Server

    Morin-Duchesne, Alexi; Ridout, David

    2015-01-01

    Virasoro Kac modules were initially introduced indirectly as representations whose characters arise in the continuum scaling limits of certain transfer matrices in logarithmic minimal models, described using Temperley-Lieb algebras. The lattice transfer operators include seams on the boundary that use Wenzl-Jones projectors. If the projectors are singular, the original prescription is to select a subspace of the Temperley-Lieb modules on which the action of the transfer operators is non-singular. However, this prescription does not, in general, yield representations of the Temperley-Lieb algebras and the Virasoro Kac modules have remained largely unidentified. Here, we introduce the appropriate algebraic framework for the lattice analysis as a quotient of the one-boundary Temperley-Lieb algebra. The corresponding standard modules are introduced and examined using invariant bilinear forms and their Gram determinants. The structures of the Virasoro Kac modules are inferred from these results and are found to be...

  20. A comparison between algebraic models of molecular spectroscopy

    CERN Document Server

    Bijker, R; Lemus, R; Arias, J M; Pérez-Bernal, F

    1998-01-01

    We discuss a symmetry-adapted algebraic (or vibron) model for molecular spectroscopy. The model is formulated in terms of tensor operators under the molecular point group. In this way, we have identified interactions that are absent in previous versions of the vibron model, in which the Hamiltonian is expressed in terms of Casimir operators and their products. The inclusion of these new interactions leads to reliable spectroscopic predictions. As an example we study the vibrational excitations of the methane molecule, and compare our results with those obtained in other algebraic models.

  1. Towards P = NP via k-SAT: A k-SAT Algorithm Using Linear Algebra on Finite Fields

    CERN Document Server

    Groff, Matt

    2011-01-01

    The problem of P vs. NP is very serious, and solutions to the problem can help save lives. This article is an attempt at solving the problem using a computer algorithm. It is presented in a fashion that will hopefully allow for easy understanding for many people and scientists from many diverse fields. In technical terms, a novel method for solving k-SAT is explained. This method is primarily based on linear algebra and finite fields. Evidence is given that this method may require only O(n^7) time and space for deterministic models. It's concluded that signi?cant evidence exists that P=NP. There is a forum devoted to this paper at http://482527.ForumRomanum.com. All are in- vited to correspond here and help with the anal- ysis of the algorithm.

  2. Some experiments investigating a possible L(1/4) algorithm for the discrete logarithm problem in algebraic curves

    OpenAIRE

    Massierer, Maike

    2014-01-01

    The function field sieve, a subexponential algorithm of complexity L(1/3) that computes discrete logarithms in finite fields, has recently been improved to an algorithm of complexity L(1/4) and subsequently to a quasi-polynomial time algorithm. We investigate whether the new ideas also apply to index calculus algorithms for computing discrete logarithms in Jacobians of algebraic curves. While we do not give a final answer to the question, we discuss a number of ideas, experiments, and possibl...

  3. Algebraic Signal Processing Theory: Cooley-Tukey Type Algorithms for Polynomial Transforms Based on Induction

    CERN Document Server

    Sandryhaila, Aliaksei; Pueschel, Markus

    2010-01-01

    A polynomial transform is the multiplication of an input vector $x\\in\\C^n$ by a matrix $\\PT_{b,\\alpha}\\in\\C^{n\\times n},$ whose $(k,\\ell)$-th element is defined as $p_\\ell(\\alpha_k)$ for polynomials $p_\\ell(x)\\in\\C[x]$ from a list $b=\\{p_0(x),\\dots,p_{n-1}(x)\\}$ and sample points $\\alpha_k\\in\\C$ from a list $\\alpha=\\{\\alpha_0,\\dots,\\alpha_{n-1}\\}$. Such transforms find applications in the areas of signal processing, data compression, and function interpolation. Important examples include the discrete Fourier and cosine transforms. In this paper we introduce a novel technique to derive fast algorithms for polynomial transforms. The technique uses the relationship between polynomial transforms and the representation theory of polynomial algebras. Specifically, we derive algorithms by decomposing the regular modules of these algebras as a stepwise induction. As an application, we derive novel $O(n\\log{n})$ general-radix algorithms for the discrete Fourier transform and the discrete cosine transform of type 4.

  4. A new ionospheric tomographic algorithm – constrained multiplicative algebraic reconstruction technique (CMART)

    Indian Academy of Sciences (India)

    Wen Debao; Liu Sanzhi

    2010-08-01

    For the limitation of the conventional multiplicative algebraic reconstruction technique (MART), a constrained MART (CMART) is proposed in this paper. In the new tomographic algorithm, a popular two-dimensional multi-point finite difference approximation of the second order Laplacian operator is used to smooth the electron density field. The feasibility and superiority of the new method are demonstrated by using the numerical simulation experiment. Finally, the CMART is used to reconstruct the regional electron density field by using the actual GNSS data under geomagnetic quiet and disturbed days. The available ionosonde data from Beijing station further validates the superiority of the new method.

  5. Laser modeling a numerical approach with algebra and calculus

    CERN Document Server

    Csele, Mark Steven

    2014-01-01

    Offering a fresh take on laser engineering, Laser Modeling: A Numerical Approach with Algebra and Calculus presents algebraic models and traditional calculus-based methods in tandem to make concepts easier to digest and apply in the real world. Each technique is introduced alongside a practical, solved example based on a commercial laser. Assuming some knowledge of the nature of light, emission of radiation, and basic atomic physics, the text:Explains how to formulate an accurate gain threshold equation as well as determine small-signal gainDiscusses gain saturation and introduces a novel pass

  6. Optical linear algebra processors - Noise and error-source modeling

    Science.gov (United States)

    Casasent, D.; Ghosh, A.

    1985-01-01

    The modeling of system and component noise and error sources in optical linear algebra processors (OLAPs) are considered, with attention to the frequency-multiplexed OLAP. General expressions are obtained for the output produced as a function of various component errors and noise. A digital simulator for this model is discussed.

  7. Logarithmic sℓ-hat (2) CFT models from Nichols algebras: I

    International Nuclear Information System (INIS)

    We construct chiral algebras that centralize rank-2 Nichols algebras with at least one fermionic generator. This gives ‘logarithmic’ W-algebra extensions of a fractional-level sℓ-hat (2) algebra. We discuss crucial aspects of the emerging general relation between Nichols algebras and logarithmic conformal field theory (CFT) models: (i) the extra input, beyond the Nichols algebra proper, needed to uniquely specify a conformal model; (ii) a relation between the CFT counterparts of Nichols algebras connected by Weyl groupoid maps; and (iii) the common double bosonization U(X) of such Nichols algebras. For an extended chiral algebra, candidates for its simple modules that are counterparts of the U(X) simple modules are proposed, as a first step toward a functorial relation between U(X) and W-algebra representation categories. (paper)

  8. An algebraic approach to modeling in software engineering

    International Nuclear Information System (INIS)

    Our work couples the formalism of universal algebras with the engineering techniques of mathematical modeling to develop a new approach to the software engineering process. Our purpose in using this combination is twofold. First, abstract data types and their specification using universal algebras can be considered a common point between the practical requirements of software engineering and the formal specification of software systems. Second, mathematical modeling principles provide us with a means for effectively analyzing real-world systems. We first use modeling techniques to analyze a system and then represent the analysis using universal algebras. The rest of the software engineering process exploits properties of universal algebras that preserve the structure of our original model. This paper describes our software engineering process and our experience using it on both research and commercial systems. We need a new approach because current software engineering practices often deliver software that is difficult to develop and maintain. Formal software engineering approaches use universal algebras to describe ''computer science'' objects like abstract data types, but in practice software errors are often caused because ''real-world'' objects are improperly modeled. There is a large semantic gap between the customer's objects and abstract data types. In contrast, mathematical modeling uses engineering techniques to construct valid models for real-world systems, but these models are often implemented in an ad hoc manner. A combination of the best features of both approaches would enable software engineering to formally specify and develop software systems that better model real systems. Software engineering, like mathematical modeling, should concern itself first and foremost with understanding a real system and its behavior under given circumstances, and then with expressing this knowledge in an executable form

  9. Fully Analyzing an Algebraic Polya Urn Model

    CERN Document Server

    Morcrette, Basile

    2012-01-01

    This paper introduces and analyzes a particular class of Polya urns: balls are of two colors, can only be added (the urns are said to be additive) and at every step the same constant number of balls is added, thus only the color compositions varies (the urns are said to be balanced). These properties make this class of urns ideally suited for analysis from an "analytic combinatorics" point-of-view, following in the footsteps of Flajolet-Dumas-Puyhaubert, 2006. Through an algebraic generating function to which we apply a multiple coalescing saddle-point method, we are able to give precise asymptotic results for the probability distribution of the composition of the urn, as well as local limit law and large deviation bounds.

  10. Profiling high performance dense linear algebra algorithms on multicore architectures for power and energy efficiency

    KAUST Repository

    Ltaief, Hatem

    2011-08-31

    This paper presents the power profile of two high performance dense linear algebra libraries i.e., LAPACK and PLASMA. The former is based on block algorithms that use the fork-join paradigm to achieve parallel performance. The latter uses fine-grained task parallelism that recasts the computation to operate on submatrices called tiles. In this way tile algorithms are formed. We show results from the power profiling of the most common routines, which permits us to clearly identify the different phases of the computations. This allows us to isolate the bottlenecks in terms of energy efficiency. Our results show that PLASMA surpasses LAPACK not only in terms of performance but also in terms of energy efficiency. © 2011 Springer-Verlag.

  11. An algorithm for identifying symmetric variables in the canonical OR-coincidence algebra system

    Institute of Scientific and Technical Information of China (English)

    Xiao-hua LI; Ji-zhong SHEN

    2014-01-01

    To simplify the process for identifying 12 types of symmetric variables in the canonical OR-coincidence (COC) algebra system, we propose a new symmetry detection algorithm based on OR-NXOR expansion. By analyzing the relationships between the coefficient matrices of sub-functions and the order coefficient subset matrices based on OR-NXOR expansion around two arbitrary logical variables, the constraint conditions of the order coefficient subset matrices are revealed for 12 types of symmetric variables. Based on the proposed constraints, the algorithm is realized by judging the order characteristic square value matrices. The proposed method avoids the transformation process from OR-NXOR expansion to AND-OR-NOT expansion, or to AND-XOR expansion, and solves the problem of completeness in the dj-map method. The application results show that, compared with traditional methods, the new algorithm is an optimal detection method in terms of applicability of the number of logical variables, detection type, and complexity of the identification process. The algorithm has been implemented in C language and tested on MCNC91 benchmarks. Experimental results show that the proposed algorithm is convenient and efficient.

  12. ADAM: Analysis of Discrete Models of Biological Systems Using Computer Algebra

    Directory of Open Access Journals (Sweden)

    Blekherman Grigoriy

    2011-07-01

    Full Text Available Abstract Background Many biological systems are modeled qualitatively with discrete models, such as probabilistic Boolean networks, logical models, Petri nets, and agent-based models, to gain a better understanding of them. The computational complexity to analyze the complete dynamics of these models grows exponentially in the number of variables, which impedes working with complex models. There exist software tools to analyze discrete models, but they either lack the algorithmic functionality to analyze complex models deterministically or they are inaccessible to many users as they require understanding the underlying algorithm and implementation, do not have a graphical user interface, or are hard to install. Efficient analysis methods that are accessible to modelers and easy to use are needed. Results We propose a method for efficiently identifying attractors and introduce the web-based tool Analysis of Dynamic Algebraic Models (ADAM, which provides this and other analysis methods for discrete models. ADAM converts several discrete model types automatically into polynomial dynamical systems and analyzes their dynamics using tools from computer algebra. Specifically, we propose a method to identify attractors of a discrete model that is equivalent to solving a system of polynomial equations, a long-studied problem in computer algebra. Based on extensive experimentation with both discrete models arising in systems biology and randomly generated networks, we found that the algebraic algorithms presented in this manuscript are fast for systems with the structure maintained by most biological systems, namely sparseness and robustness. For a large set of published complex discrete models, ADAM identified the attractors in less than one second. Conclusions Discrete modeling techniques are a useful tool for analyzing complex biological systems and there is a need in the biological community for accessible efficient analysis tools. ADAM provides

  13. Weak quasitriangular Quasi-Hopf algebra structure of minimal models

    OpenAIRE

    Teschner, J. A.

    1995-01-01

    The chiral vertex operators for the minimal models are constructed and used to define a fusion product of representations. The existence of commutativity and associativity operations is proved. The matrix elements of the associativity operations are shown to be given in terms of the 6-j symbols of the weak quasitriangular quasi-Hopf algebra obtained by truncating $\\usl$ at roots of unity.

  14. Supersymmetry and DLCQ Limit of Lie 3-algebra Model of M-theory

    OpenAIRE

    Sato, Matsuo

    2011-01-01

    In arXiv:1003.4694, we proposed two models of M-theory, Hermitian 3-algebra model and Lie 3-algebra model. In this paper, we study the Lie 3-algebra model with a Lorentzian Lie 3-algebra. This model is ghost-free despite the Lorentzian 3-algebra. We show that our model satisfies two criteria as a model of M-theory. First, we show that the model possesses N=1 supersymmetry in eleven dimensions. Second, we show the model reduces to BFSS matrix theory with finite size matrices in a DLCQ limit.

  15. How algebraic Bethe ansatz works for integrable model

    CERN Document Server

    Fadeev, L

    1996-01-01

    I study the technique of Algebraic Bethe Ansatz for solving integrable models and show how it works in detail on the simplest example of spin 1/2 XXX magnetic chain. Several other models are treated more superficially, only the specific details are given. Several parameters, appearing in these generalizations: spin s, anisotropy parameter \\ga, shift \\om in the alternating chain, allow to include in our treatment most known examples of soliton theory, including relativistic model of Quantum Field Theory.

  16. Generalization of Richardson-Gaudin models to rank-2 algebras

    Energy Technology Data Exchange (ETDEWEB)

    Errea, B; Lerma, S; Dukelsky, J; Dimitrova, S S; Pittel, S; Van Isacker, P; Gueorguiev, V G

    2006-07-20

    A generalization of Richardson-Gaudin models to the rank-2 SO(5) and SO(3,2) algebras is used to describe systems of two kinds of fermions or bosons interacting through a pairing force. They are applied to the proton-neutron neutron isovector pairing model and to the Interacting Boson Model 2, in the transition from vibration to gamma-soft nuclei, respectively. In both cases, the integrals of motion and their eigenvalues are obtained.

  17. Modelling and Analysis of Network Security - an Algebraic Approach

    OpenAIRE

    Qian ZHANG; Jiang, Ying; Wu, Peng

    2015-01-01

    Game theory has been applied to investigate network security. But different security scenarios were often modeled via different types of games and analyzed in an ad-hoc manner. In this paper, we propose an algebraic approach for modeling and analyzing uniformly several types of network security games. This approach is based on a probabilistic extension of the value-passing Calculus of Communicating Systems (CCS) which is regarded as a Generative model for Probabilistic Value-passing CCS (PVCC...

  18. Algebraic turbulence modeling for unstructured and adaptive meshes

    Science.gov (United States)

    Mavriplis, Dimitri J.

    1990-01-01

    An algebraic turbulence model based on the Baldwin-Lomax model, has been implemented for use on unstructured grids. The implementation is based on the use of local background structured turbulence meshes. At each time-step, flow variables are interpolated from the unstructured mesh onto the background structured meshes, the turbulence model is executed on these meshes, and the resulting eddy viscosity values are interpolated back to the unstructured mesh. Modifications to the algebraic model were required to enable the treatment of more complicated flows, such as confluent boundary layers and wakes. The model is used in conjuction with an efficient unstructured multigrid finite-element Navier-Stokes solver in order to compute compressible turbulent flows on fully unstructured meshes. Solutions about single and multiple element airfoils are obtained and compared with experimental data.

  19. The BC1 quantum elliptic model: algebraic forms, hidden algebra sl(2), polynomial eigenfunctions

    International Nuclear Information System (INIS)

    The potential of the BC1 quantum elliptic model is a superposition of two Weierstrass functions with a doubling of both periods (two coupling constants). The BC1 elliptic model degenerates to an A1 elliptic model characterized by the Lamé Hamiltonian. It is shown that in the space of the BC1 elliptic invariant, the potential becomes a rational function, while the flat space metric becomes a polynomial. The model possesses the hidden sl(2) algebra for arbitrary coupling constants: it is equivalent to the sl(2) quantum top in three different magnetic fields. It is shown that three one-parametric families of coupling constants exist, for which a finite number of polynomial eigenfunctions (up to a factor) occur. (paper)

  20. The Hidden Quantum Group of the 8-vertex Free Fermion Model: q-Clifford Algebras

    OpenAIRE

    Cuerno, Rodolfo; Gómez, César; López Manzanares, Esperanza; Sierra, Germán

    1993-01-01

    We prove in this paper that the elliptic $R$--matrix of the eight vertex free fermion model is the intertwiner $R$--matrix of a quantum deformed Clifford--Hopf algebra. This algebra is constructed by affinization of a quantum Hopf deformation of the Clifford algebra.

  1. Integrability in three dimensions: Algebraic Bethe ansatz for anyonic models

    Science.gov (United States)

    Khachatryan, Sh.; Ferraz, A.; Klümper, A.; Sedrakyan, A.

    2015-10-01

    We extend basic properties of two dimensional integrable models within the Algebraic Bethe Ansatz approach to 2 + 1 dimensions and formulate the sufficient conditions for the commutativity of transfer matrices of different spectral parameters, in analogy with Yang-Baxter or tetrahedron equations. The basic ingredient of our models is the R-matrix, which describes the scattering of a pair of particles over another pair of particles, the quark-anti-quark (meson) scattering on another quark-anti-quark state. We show that the Kitaev model belongs to this class of models and its R-matrix fulfills well-defined equations for integrability.

  2. Integrability in three dimensions: Algebraic Bethe ansatz for anyonic models

    Directory of Open Access Journals (Sweden)

    Sh. Khachatryan

    2015-10-01

    Full Text Available We extend basic properties of two dimensional integrable models within the Algebraic Bethe Ansatz approach to 2+1 dimensions and formulate the sufficient conditions for the commutativity of transfer matrices of different spectral parameters, in analogy with Yang–Baxter or tetrahedron equations. The basic ingredient of our models is the R-matrix, which describes the scattering of a pair of particles over another pair of particles, the quark-anti-quark (meson scattering on another quark-anti-quark state. We show that the Kitaev model belongs to this class of models and its R-matrix fulfills well-defined equations for integrability.

  3. Polynomial Lie algebra methods in solving the second-harmonic generation model: some exact and approximate calculations

    OpenAIRE

    Karassiov, V. P.; A. A. Gusev; Vinitsky, S. I.

    2001-01-01

    We compare exact and SU(2)-cluster approximate calculation schemes to determine dynamics of the second-harmonic generation model using its reformulation in terms of a polynomial Lie algebra $su_{pd}(2)$ and related spectral representations of the model evolution operator realized in algorithmic forms. It enabled us to implement computer experiments exhibiting a satisfactory accuracy of the cluster approximations in a large range of characteristic model parameters.

  4. Algebraic fermion models and nuclear structure physics

    International Nuclear Information System (INIS)

    Recent experimental and theoretical developments are generating renewed interest in the nuclear SU(3) shell model, and this extends to the symplectic model, with its Sp(6,R) symmetry, which is a natural multi-(ℎ/2π)ω extension of the SU(3) theory. First and foremost, an understanding of how the dynamics of a quantum rotor is embedded in the shell model has established it as the model of choice for describing strongly deformed systems. Second, the symplectic model extension of the 0-(ℎ/2π)ω theory can be used to probe additional degrees of freedom, like core polarization and vorticity modes that play a key role in providing a full description of quadrupole collectivity. Third, the discovery and understanding of pseudo-spin has allowed for an extension of the theory from light (A≤40) to heavy (A≥100) nuclei. Fourth, a user-friendly computer code for calculating reduced matrix elements of operators that couple SU(3) representations is now available. And finally, since the theory is designed to cope with deformation in a natural way, microscopic features of deformed systems can be probed; for example, the theory is now being employed to study double beta decay and thereby serves to probe the validity of the standard model of particles and their interactions. A subset of these topics will be considered in this course--examples cited include: a consideration of the origin of pseudo-spin symmetry; a SU(3)-based interpretation of the coupled-rotor model, early results of double beta decay studies; and some recent developments on the pseudo-SU(3) theory. Nothing will be said about other fermion-based theories; students are referred to reviews in the literature for reports on developments in these related areas

  5. Algebraic Turbulence-Chemistry Interaction Model

    Science.gov (United States)

    Norris, Andrew T.

    2012-01-01

    The results of a series of Perfectly Stirred Reactor (PSR) and Partially Stirred Reactor (PaSR) simulations are compared to each other over a wide range of operating conditions. It is found that the PaSR results can be simulated by a PSR solution with just an adjusted chemical reaction rate. A simple expression has been developed that gives the required change in reaction rate for a PSR solution to simulate the PaSR results. This expression is the basis of a simple turbulence-chemistry interaction model. The interaction model that has been developed is intended for use with simple one-step global reaction mechanisms and for steady-state flow simulations. Due to the simplicity of the model there is very little additional computational cost in adding it to existing CFD codes.

  6. Algebraic spin liquid in an exactly solvable spin model

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Hong; Zhang, Shou-Cheng; Kivelson, Steven A.; /Stanford U., Phys. Dept.

    2010-03-25

    We have proposed an exactly solvable quantum spin-3/2 model on a square lattice. Its ground state is a quantum spin liquid with a half integer spin per unit cell. The fermionic excitations are gapless with a linear dispersion, while the topological 'vison' excitations are gapped. Moreover, the massless Dirac fermions are stable. Thus, this model is, to the best of our knowledge, the first exactly solvable model of half-integer spins whose ground state is an 'algebraic spin liquid.'

  7. The supersymmetry extended Weyl algebra and Casalbuoni's G4 model

    International Nuclear Information System (INIS)

    We briefly review the classical version of Casalbuoni's G4 supersymmetric model (i.e. the single particle version of the scalar chiral supermultiplet) with particular emphasis on the role played by the chirality. We show that the off-mass-shell commutators of the quantum model can be derived from the Lie algebra of the Weyl (i.e. Poincare plus dilatations) group extended by supersymmetry. The proper-time wavefunctions of the off-mass-shell states satisfy equations which clarify the role of the auxiliary fields of quantum field theory. (orig.)

  8. A Multiple—Valued Algebra for Modeling MOS VLSI Circuits at Switch—Level

    Institute of Scientific and Technical Information of China (English)

    胡谋

    1992-01-01

    A multiple-valued algebra for modeling MOS VLSI circuits at switch-level is proposed in this paper,Its structure and properties are studied.This algebra can be used to transform a MOS digital circuit to a swith-level algebraic expression so as to generate the truth table for the circuit and to derive a Boolean expression for it.In the paper,methods to construct a switch-level algebraic expression for a circuit and methods to simplify expressions are given.This algebra provides a new tool for MOS VLSI circuit design and analysis.

  9. Clifford algebra and the projective model of Hyperbolic spaces

    OpenAIRE

    Sokolov, Andrey

    2016-01-01

    I apply the algebraic framework developed in [1] to study geometry of hyperbolic spaces in 1, 2, and 3 dimensions. The background material on projectivised Clifford algebras and their application to Cayley-Klein geometries is described in [2].

  10. Software Engineering and Complexity in Effective Algebraic Geometry

    CERN Document Server

    Heintz, Joos; Paredes, Andres Rojas

    2011-01-01

    We introduce the notion of a robust parameterized arithmetic circuit for the evaluation of algebraic families of multivariate polynomials. Based on this notion, we present a computation model, adapted to Scientific Computing, which captures all known branching parsimonious symbolic algorithms in effective Algebraic Geometry. We justify this model by arguments from Software Engineering. Finally we exhibit a class of simple elimination problems of effective Algebraic Geometry which require exponential time to be solved by branching parsimonious algorithms of our computation model.

  11. An Algebraic Graphical Model for Decision with Uncertainties, Feasibilities, and Utilities

    CERN Document Server

    Pralet, C; Verfaillie, G; 10.1613/jair.2151

    2011-01-01

    Numerous formalisms and dedicated algorithms have been designed in the last decades to model and solve decision making problems. Some formalisms, such as constraint networks, can express "simple" decision problems, while others are designed to take into account uncertainties, unfeasible decisions, and utilities. Even in a single formalism, several variants are often proposed to model different types of uncertainty (probability, possibility...) or utility (additive or not). In this article, we introduce an algebraic graphical model that encompasses a large number of such formalisms: (1) we first adapt previous structures from Friedman, Chu and Halpern for representing uncertainty, utility, and expected utility in order to deal with generic forms of sequential decision making; (2) on these structures, we then introduce composite graphical models that express information via variables linked by "local" functions, thanks to conditional independence; (3) on these graphical models, we finally define a simple class ...

  12. Proceedings Second International Workshop on Algebraic Methods in Model-based Software Engineering

    CERN Document Server

    Durán, Francisco

    2011-01-01

    Over the past years there has been quite a lot of activity in the algebraic community about using algebraic methods for providing support to model-driven software engineering. The aim of this workshop is to gather researchers working on the development and application of algebraic methods to provide rigorous support to model-based software engineering. The topics relevant to the workshop are all those related to the use of algebraic methods in software engineering, including but not limited to: formally specifying and verifying model-based software engineering concepts and related ones (MDE, UML, OCL, MOF, DSLs, ...); tool support for the above; integration of formal and informal methods; and theoretical frameworks (algebraic, rewriting-based, category theory-based, ...). The workshop's main goal is to examine, discuss, and relate the existing projects within the algebraic community that address common open-issues in model-driven software engineering.

  13. Topological basis realization for BMW algebra and Heisenberg XXZ spin chain model

    Science.gov (United States)

    Liu, Bo; Xue, Kang; Wang, Gangcheng; Liu, Ying; Sun, Chunfang

    2015-04-01

    In this paper, we study three-dimensional (3D) reduced Birman-Murakami-Wenzl (BMW) algebra based on topological basis theory. Several examples of BMW algebra representations are reviewed. We also discuss a special solution of BMW algebra, which can be used to construct Heisenberg XXZ model. The theory of topological basis provides a useful method to solve quantum spin chain models. It is also shown that the ground state of XXZ spin chain is superposition state of topological basis.

  14. A U(1) Current Algebra Model Coupled to 2D-Gravity

    OpenAIRE

    Stoilov, M.; Zaikov, R.

    1993-01-01

    We consider a simple model of a scalar field with $U(1)$ current algebra gauge symmetry coupled to $2D$-gravity in order to clarify the origin of Stuckelberg symmetry in the $w_{\\infty}$-gravity theory. An analogous symmetry takes place in our model too. The possible central extension of the complete symmetry algebra and the corresponding critical dimension have been found. The analysis of the Hamiltonian and the constraints shows that the generators of the current algebra, the reparametrizat...

  15. A New Algebraic Modelling Approach to Distributed Problem-Solving in MAS

    Institute of Scientific and Technical Information of China (English)

    帅典勋; 邓志东

    2002-01-01

    This paper is devoted to a new algebraic modelling approach to distributed problem-solving in multi-agent systems (MAS), which is featured by a unified framework for describing and treating social behaviors, social dynamics and social intelligence. A conceptual architecture of algebraic modelling is presented. The algebraic modelling of typical social behaviors, social situation and social dynamics is discussed in the context of distributed problemsolving in MAS. The comparison and simulation on distributed task allocations and resource assignments in MAS show more advantages of the algebraic approach than other conventional methods.

  16. Real Algebraic Geometry

    CERN Document Server

    Mahé, Louis; Roy, Marie-Françoise

    1992-01-01

    Ten years after the first Rennes international meeting on real algebraic geometry, the second one looked at the developments in the subject during the intervening decade - see the 6 survey papers listed below. Further contributions from the participants on recent research covered real algebra and geometry, topology of real algebraic varieties and 16thHilbert problem, classical algebraic geometry, techniques in real algebraic geometry, algorithms in real algebraic geometry, semialgebraic geometry, real analytic geometry. CONTENTS: Survey papers: M. Knebusch: Semialgebraic topology in the last ten years.- R. Parimala: Algebraic and topological invariants of real algebraic varieties.- Polotovskii, G.M.: On the classification of decomposing plane algebraic curves.- Scheiderer, C.: Real algebra and its applications to geometry in the last ten years: some major developments and results.- Shustin, E.L.: Topology of real plane algebraic curves.- Silhol, R.: Moduli problems in real algebraic geometry. Further contribu...

  17. Clifford algebras geometric modelling and chain geometries with application in kinematics

    CERN Document Server

    Klawitter, Daniel

    2015-01-01

    After revising known representations of the group of Euclidean displacements Daniel Klawitter gives a comprehensive introduction into Clifford algebras. The Clifford algebra calculus is used to construct new models that allow descriptions of the group of projective transformations and inversions with respect to hyperquadrics. Afterwards, chain geometries over Clifford algebras and their subchain geometries are examined. The author applies this theory and the developed methods to the homogeneous Clifford algebra model corresponding to Euclidean geometry. Moreover, kinematic mappings for special Cayley-Klein geometries are developed. These mappings allow a description of existing kinematic mappings in a unifying framework.  Contents Models and representations of classical groups Clifford algebras, chain geometries over Clifford algebras Kinematic mappings for Pin and Spin groups Cayley-Klein geometries Target Groups Researchers and students in the field of mathematics, physics, and mechanical engineering About...

  18. Algorithms and Methods for High-Performance Model Predictive Control

    DEFF Research Database (Denmark)

    Frison, Gianluca

    The goal of this thesis is to investigate algorithms and methods to reduce the solution time of solvers for Model Predictive Control (MPC). The thesis is accompanied with an open-source toolbox for High-Performance implementation of solvers for MPC (HPMPC), that contains the source code of all...... proposed, aiming at improving the computational performance in case of small matrices. About the algorithms, they are built on top of the proposed linear algebra, and they are tailored to exploit the high-level structure of the MPC problems, with special care on reducing the computational complexity....

  19. Algebraic Traveling Wave Solutions of a Non-local Hydrodynamic-type Model

    International Nuclear Information System (INIS)

    In this paper we consider the algebraic traveling wave solutions of a non-local hydrodynamic-type model. It is shown that algebraic traveling wave solutions exist if and only if an associated first order ordinary differential system has invariant algebraic curve. The dynamical behavior of the associated ordinary differential system is analyzed. Phase portraits of the associated ordinary differential system is provided under various parameter conditions. Moreover, we classify algebraic traveling wave solutions of the model. Some explicit formulas of smooth solitary wave and cuspon solutions are obtained

  20. Algebraic model for single-particle energies of $\\Lambda$ hypernuclei

    CERN Document Server

    Fortunato, L

    2016-01-01

    A model is proposed for the spectrum of $\\Lambda$ hypernuclei based on the $u(3)\\times u(2)$ Lie algebra, in which the internal degrees of freedom of the spin-1/2 $\\Lambda$ particle are treated in the Fermionic $u(2)$ scheme, while the motion of the hyperon inside a nucleus is described in the Bosonic $u(3)$ harmonic oscillator scheme. Within this model, a simple formula for single-particle energies of the $\\Lambda$ particle is obtained from the natural dynamical symmetry. The formula is applied to the experimental data on the reaction spectroscopy for the $^{89}_\\Lambda$Y and $^{51}_\\Lambda$V hypernuclei, providing a clear theoretical interpretation of the observed structures.

  1. 07071 Report on Dagstuhl Seminar -- Web Information Retrieval and Linear Algebra Algorithms

    OpenAIRE

    Frommer, Andreas; Mahoney, Michael W.; Szyld, Daniel B.

    2007-01-01

    A seminar concentrating on the intersection of the fields of information retrieval and other web-related aspects with numerical and applied linear algebra techniques was held with the attendance of scientists from industry and academia.

  2. Algebraic models of deviant modal operators based on de Morgan and Kleene lattices

    OpenAIRE

    Cattaneo, G.; Ciucci, DE; Dubois, D.

    2011-01-01

    An algebraic model of a kind of modal extension of de Morgan logic is described under the name MDS5 algebra. The main properties of this algebra can be summarized as follows: (1) it is based on a de Morgan lattice, rather than a Boolean algebra; (2) a modal necessity operator that satisfies the axioms N, K, T, and 5 (and as a consequence also B and 4) of modal logic is introduced; it allows one to introduce a modal possibility by the usual combination of necessity operation and...

  3. Phases and phase transitions in the algebraic microscopic shell model

    Directory of Open Access Journals (Sweden)

    Georgieva A. I.

    2016-01-01

    Full Text Available We explore the dynamical symmetries of the shell model number conserving algebra, which define three types of pairing and quadrupole phases, with the aim to obtain the prevailing phase or phase transition for the real nuclear systems in a single shell. This is achieved by establishing a correspondence between each of the pairing bases with the Elliott’s SU(3 basis that describes collective rotation of nuclear systems. This allows for a complete classification of the basis states of different number of particles in all the limiting cases. The probability distribution of the SU(3 basis states within theirs corresponding pairing states is also obtained. The relative strengths of dynamically symmetric quadrupole-quadrupole interaction in respect to the isoscalar, isovector and total pairing interactions define a control parameter, which estimates the importance of each term of the Hamiltonian in the correct reproduction of the experimental data for the considered nuclei.

  4. Re"modeling" College Algebra: An Active Learning Approach

    Science.gov (United States)

    Pinzon, D.; Pinzon, K.; Stackpole, M.

    2016-01-01

    In this paper, we discuss active learning in College Algebra at Georgia Gwinnett College. This approach has been used in more than 20 sections of College Algebra taught by the authors in the past four semesters. Students work in small, structured groups on guided inquiry activities after watching 15-20 minutes of videos before class. We discuss a…

  5. Algebraic structures generating reaction-diffusion models: the activator-substrate system

    OpenAIRE

    Palese, Marcella

    2015-01-01

    We shall construct a class of nonlinear reaction-diffusion equations starting from an infinitesimal algebraic skeleton. Our aim is to explore the possibility of an algebraic foundation of integrability properties and of stability of equilibrium states associated with nonlinear models describing patterns formation.

  6. Sigma-model Solutions and Intersecting p-Branes Related to Lie Algebras

    OpenAIRE

    Grebeniuk, M. A.; Ivashchuk, V. D.

    1998-01-01

    A family of Majumdar-Papapetrou type solutions in sigma-model of p-brane origin is obtained for all direct sums of finite-dimensional simple Lie algebras. Several examples of p-brane dyonic configurations in D=10 (IIA) and D=11 supergravities corresponding to the Lie algebra sl(3,C) are considered.

  7. Linear algebra

    CERN Document Server

    Edwards, Harold M

    1995-01-01

    In his new undergraduate textbook, Harold M Edwards proposes a radically new and thoroughly algorithmic approach to linear algebra Originally inspired by the constructive philosophy of mathematics championed in the 19th century by Leopold Kronecker, the approach is well suited to students in the computer-dominated late 20th century Each proof is an algorithm described in English that can be translated into the computer language the class is using and put to work solving problems and generating new examples, making the study of linear algebra a truly interactive experience Designed for a one-semester course, this text adopts an algorithmic approach to linear algebra giving the student many examples to work through and copious exercises to test their skills and extend their knowledge of the subject Students at all levels will find much interactive instruction in this text while teachers will find stimulating examples and methods of approach to the subject

  8. Index-aware model order reduction methods applications to differential-algebraic equations

    CERN Document Server

    Banagaaya, N; Schilders, W H A

    2016-01-01

    The main aim of this book is to discuss model order reduction (MOR) methods for differential-algebraic equations (DAEs) with linear coefficients that make use of splitting techniques before applying model order reduction. The splitting produces a system of ordinary differential equations (ODE) and a system of algebraic equations, which are then reduced separately. For the reduction of the ODE system, conventional MOR methods can be used, whereas for the reduction of the algebraic systems new methods are discussed. The discussion focuses on the index-aware model order reduction method (IMOR) and its variations, methods for which the so-called index of the original model is automatically preserved after reduction.

  9. Algebraic Bethe ansatz for integrable extended Hubbard models arising from supersymmetric group solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bracken, Anthony J.; Ge Xiangyu; Gould, Mark D.; Links, Jon; Zhou Huanqiang [Centre for Mathematical Physics, University of Queensland, Brisbane, QLD (Australia)

    2001-06-01

    Integrable extended Hubbard models arising from symmetric group solutions are examined in the framework of the graded quantum inverse scattering method. The Bethe ansatz equations for all these models are derived by using the algebraic Bethe ansatz method. (author)

  10. Algorithmic Issues in Modeling Motion

    DEFF Research Database (Denmark)

    Agarwal, P. K; Guibas, L. J; Edelsbrunner, H.;

    2003-01-01

    This article is a survey of research areas in which motion plays a pivotal role. The aim of the article is to review current approaches to modeling motion together with related data structures and algorithms, and to summarize the challenges that lie ahead in producing a more unified theory...

  11. Analysis of DIRAC's behavior using model checking with process algebra

    International Nuclear Information System (INIS)

    DIRAC is the grid solution developed to support LHCb production activities as well as user data analysis. It consists of distributed services and agents delivering the workload to the grid resources. Services maintain database back-ends to store dynamic state information of entities such as jobs, queues, staging requests, etc. Agents use polling to check and possibly react to changes in the system state. Each agent's logic is relatively simple; the main complexity lies in their cooperation. Agents run concurrently, and collaborate using the databases as shared memory. The databases can be accessed directly by the agents if running locally or through a DIRAC service interface if necessary. This shared-memory model causes entities to occasionally get into inconsistent states. Tracing and fixing such problems becomes formidable due to the inherent parallelism present. We propose more rigorous methods to cope with this. Model checking is one such technique for analysis of an abstract model of a system. Unlike conventional testing, it allows full control over the parallel processes execution, and supports exhaustive state-space exploration. We used the mCRL2 language and toolset to model the behavior of two related DIRAC subsystems: the workload and storage management system. Based on process algebra, mCRL2 allows defining custom data types as well as functions over these. This makes it suitable for modeling the data manipulations made by DIRAC's agents. By visualizing the state space and replaying scenarios with the toolkit's simulator, we have detected race-conditions and deadlocks in these systems, which, in several cases, were confirmed to occur in the reality. Several properties of interest were formulated and verified with the tool. Our future direction is automating the translation from DIRAC to a formal model.

  12. Analysis of DIRAC's behavior using model checking with process algebra

    Science.gov (United States)

    Remenska, Daniela; Templon, Jeff; Willemse, Tim; Bal, Henri; Verstoep, Kees; Fokkink, Wan; Charpentier, Philippe; Graciani Diaz, Ricardo; Lanciotti, Elisa; Roiser, Stefan; Ciba, Krzysztof

    2012-12-01

    DIRAC is the grid solution developed to support LHCb production activities as well as user data analysis. It consists of distributed services and agents delivering the workload to the grid resources. Services maintain database back-ends to store dynamic state information of entities such as jobs, queues, staging requests, etc. Agents use polling to check and possibly react to changes in the system state. Each agent's logic is relatively simple; the main complexity lies in their cooperation. Agents run concurrently, and collaborate using the databases as shared memory. The databases can be accessed directly by the agents if running locally or through a DIRAC service interface if necessary. This shared-memory model causes entities to occasionally get into inconsistent states. Tracing and fixing such problems becomes formidable due to the inherent parallelism present. We propose more rigorous methods to cope with this. Model checking is one such technique for analysis of an abstract model of a system. Unlike conventional testing, it allows full control over the parallel processes execution, and supports exhaustive state-space exploration. We used the mCRL2 language and toolset to model the behavior of two related DIRAC subsystems: the workload and storage management system. Based on process algebra, mCRL2 allows defining custom data types as well as functions over these. This makes it suitable for modeling the data manipulations made by DIRAC's agents. By visualizing the state space and replaying scenarios with the toolkit's simulator, we have detected race-conditions and deadlocks in these systems, which, in several cases, were confirmed to occur in the reality. Several properties of interest were formulated and verified with the tool. Our future direction is automating the translation from DIRAC to a formal model.

  13. Y(sl(2)) Algebra Application in Extended Hydrogen Atom and Monopole Models

    Institute of Scientific and Technical Information of China (English)

    TIAN Li-Jun; ZHANG Hong-Biao; JIN Shuo; XUE Kang

    2004-01-01

    We present the extended hydrogen atom and monopole-hydrogen atom theory through generalizing the usual hydrogen atom model and with a monopole model respectively, in which Y (sl(2) ) algebras are realized. We derive the Hamiltonians of the two models based on the Y(sl(2) ) and the generalized Pauli equation. The energy spectra of the systems are also given in terms of Yangian algebra and quantum mechanics.

  14. Model Checking Process Algebra of Communicating Resources for Real-time Systems

    DEFF Research Database (Denmark)

    Boudjadar, Jalil; Kim, Jin Hyun; Larsen, Kim Guldstrand;

    2014-01-01

    This paper presents a new process algebra, called PACOR, for real-time systems which deals with resource constrained timed behavior as an improved version of the ACSR algebra. We define PACOR as a Process Algebra of Communicating Resources which allows to express preemptiveness, urgent ness and...... original semantics of PACOR and enables the verification of PACOR systems using symbolic model checking in UPPAAL and statistical model checking UPPAAL SMC. Finally we provide an example to illustrate system specification in PACOR, translation and verification....

  15. Model checking process algebra of communicating resources for real-time systems

    DEFF Research Database (Denmark)

    Boudjadar, Jalil; Kim, Jin Hyun; Larsen, Kim Guldstrand;

    2014-01-01

    This paper presents a new process algebra, called PACoR, for real-time systems which deals with resource- constrained timed behavior as an improved version of the ACSR algebra. We define PACoR as a Process Algebra of Communicating Resources which allows to explicitly express preemptiveness...... preserves the original semantics of PACoR and enables the verification of PACoR systems using symbolic model checking in Uppaal and statistical model checking UppaalSMC. Finally we provide an example to illustrate system specification in PACoR, translation and verification....

  16. Towards scalable algorithms with formal guarantees for Lyapunov analysis of control systems via algebraic optimization

    OpenAIRE

    Ahmadi, Amir Ali; Parrilo, Pablo A.

    2014-01-01

    Exciting recent developments at the interface of optimization and control have shown that several fundamental problems in dynamics and control, such as stability, collision avoidance, robust performance, and controller synthesis can be addressed by a synergy of classical tools from Lyapunov theory and modern computational techniques from algebraic optimization. In this paper, we give a brief overview of our recent research efforts (with various coauthors) to (i) enhance the scalability of the...

  17. A novel hybrid optimization algorithm for diferential-algebraic control problems

    Directory of Open Access Journals (Sweden)

    F. S. Lobato

    2007-09-01

    Full Text Available Dynamic optimization problems can be numerically solved by direct, indirect and Hamilton-Jacobi-Bellman methods. In this paper, the differential-algebraic approach is incorporated into a hybrid method, extending the concepts of structural and differential indexes, consistent initialization analysis, index reduction and dynamic degrees of freedom to the optimal control problem. The resultant differential-algebraic optimal control problem is solved in the following steps: transformation of the original problem into a standard nonlinear programming problem that provides control and state variables, switching time estimates and costate variables profiles with the DIRCOL code; definition of the switching function and the automatically generated sequence of index-1 differential-algebraic boundary value problems from Pontryagin’s minimum principle by using the developed Otima code; and finally, application of the COLDAE code with the results of the direct method as an initial guess. The proposed hybrid method is illustrated with a pressure-constrained batch reactor optimization problem associated with the slack variable method.

  18. Currents algebra for an atom-molecule Bose-Einstein condensate model

    OpenAIRE

    Filho, Gilberto N. Santos

    2016-01-01

    I present an interconversion currents algebra for an atom-molecule Bose-Einstein condensate model and use it to get the quantum dynamics of the currents. For different choices of the Hamiltonian parameters I get different currents dynamics.

  19. Tracking Problem Solving by Multivariate Pattern Analysis and Hidden Markov Model Algorithms

    Science.gov (United States)

    Anderson, John R.

    2012-01-01

    Multivariate pattern analysis can be combined with Hidden Markov Model algorithms to track the second-by-second thinking as people solve complex problems. Two applications of this methodology are illustrated with a data set taken from children as they interacted with an intelligent tutoring system for algebra. The first "mind reading" application…

  20. Marginalization algorithm for compositional models

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Radim; Kratochvíl, Václav

    Paris: Editions EDK, 2006 - (Bouchon-Meunier, B.; Yager, R.), s. 2300-2307 ISBN 2-84254-112-X. [IPMU 2006 /11./. Paris (FR), 02.07.2006-07.07.2006] R&D Projects: GA MŠk 1M0572; GA AV ČR IAA2075302 Institutional research plan: CEZ:AV0Z10750506 Keywords : compositional model * multidimensional distribution * Bayesian network * marginalization * algorithm Subject RIV: BA - General Mathematics

  1. Off-critical W∞ and Virasoro algebras as dynamical symmetries of the integrable models

    International Nuclear Information System (INIS)

    An infinite set of new non commuting conserved charges in a specific class of perturbed CFT's is founded and a criterion for their existence is presented. They appear to be higher momenta of the already known commuting conserved currents. The algebra they close consists of two non commuting W ∞ algebras. Various Virasoro subalgebras of the full symmetry algebra are founded. It is shown on the examples of the perturbed Ising and Potts models that one of them plays an essential role in the computation of the correlation functions of the fields of the theory. (author)

  2. Direct Model Checking Matrix Algorithm

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hong Tao; Hans Kleine Büning; Li-Fu Wang

    2006-01-01

    During the last decade, Model Checking has proven its efficacy and power in circuit design, network protocol analysis and bug hunting. Recent research on automatic verification has shown that no single model-checking technique has the edge over all others in all application areas. So, it is very difficult to determine which technique is the most suitable for a given model. It is thus sensible to apply different techniques to the same model. However, this is a very tedious and time-consuming task, for each algorithm uses its own description language. Applying Model Checking in software design and verification has been proved very difficult. Software architectures (SA) are engineering artifacts that provide high-level and abstract descriptions of complex software systems. In this paper a Direct Model Checking (DMC) method based on Kripke Structure and Matrix Algorithm is provided. Combined and integrated with domain specific software architecture description languages (ADLs), DMC can be used for computing consistency and other critical properties.

  3. Algebraic multigrid preconditioner for the cardiac bidomain model.

    Science.gov (United States)

    Plank, Gernot; Liebmann, Manfred; Weber dos Santos, Rodrigo; Vigmond, Edward J; Haase, Gundolf

    2007-04-01

    The bidomain equations are considered to be one of the most complete descriptions of the electrical activity in cardiac tissue, but large scale simulations, as resulting from discretization of an entire heart, remain a computational challenge due to the elliptic portion of the problem, the part associated with solving the extracellular potential. In such cases, the use of iterative solvers and parallel computing environments are mandatory to make parameter studies feasible. The preconditioned conjugate gradient (PCG) method is a standard choice for this problem. Although robust, its efficiency greatly depends on the choice of preconditioner. On structured grids, it has been demonstrated that a geometric multigrid preconditioner performs significantly better than an incomplete LU (ILU) preconditioner. However, unstructured grids are often preferred to better represent organ boundaries and allow for coarser discretization in the bath far from cardiac surfaces. Under these circumstances, algebraic multigrid (AMG) methods are advantageous since they compute coarser levels directly from the system matrix itself, thus avoiding the complexity of explicitly generating coarser, geometric grids. In this paper, the performance of an AMG preconditioner (BoomerAMG) is compared with that of the standard ILU preconditioner and a direct solver. BoomerAMG is used in two different ways, as a preconditioner and as a standalone solver. Two 3-D simulation examples modeling the induction of arrhythmias in rabbit ventricles were used to measure performance in both sequential and parallel simulations. It is shown that the AMG preconditioner is very well suited for the solution of the bidomain equation, being clearly superior to ILU preconditioning in all regards, with speedups by factors in the range 5.9-7.7. PMID:17405366

  4. Excel Spreadsheets for Algebra: Improving Mental Modeling for Problem Solving

    Science.gov (United States)

    Engerman, Jason; Rusek, Matthew; Clariana, Roy

    2014-01-01

    This experiment investigates the effectiveness of Excel spreadsheets in a high school algebra class. Students in the experiment group convincingly outperformed the control group on a post lesson assessment. The student responses, teacher observations involving Excel spreadsheet revealed that it operated as a mindtool, which formed the users'…

  5. Equivalent construction of the infinitesimal time translation operator in algebraic dynamics algorithm for partial differential evolution equation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We give an equivalent construction of the infinitesimal time translation operator for partial differential evolution equation in the algebraic dynamics algorithm proposed by Shun-Jin Wang and his students. Our construction involves only simple partial differentials and avoids the derivative terms of δ function which appear in the course of computation by means of Wang-Zhang operator. We prove Wang’s equivalent theorem which says that our construction and Wang-Zhang’s are equivalent. We use our construction to deal with several typical equations such as nonlinear advection equation, Burgers equation, nonlinear Schrodinger equation, KdV equation and sine-Gordon equation, and obtain at least second order approximate solutions to them. These equations include the cases of real and complex field variables and the cases of the first and the second order time derivatives.

  6. Supersymmetric extension of the reflection equation algebra and integrable boundary conditions in doped spin-1 model

    International Nuclear Information System (INIS)

    The reflection equation algebra of Sklyanin is extended to the supersymmetric case. A graded reflection equation algebra is proposed and the corresponding graded (supersymmetric) boundary quantum inverse scattering method (QISM) is formulated. As an application, integrable open-boundary conditions for the doped spin-1 chain of the supersymmetric t-J model are studied in the framework of the boundary QISM. Diagonal boundary K-matrices are found and four classes of integrable boundary terms are determined. (author)

  7. The classical origin of quantum affine algebra in squashed sigma models

    OpenAIRE

    Kawaguchi, Io; Matsumoto, Takuya; Yoshida, Kentaroh

    2012-01-01

    We consider a quantum affine algebra realized in two-dimensional non-linear sigma models with target space three-dimensional squashed sphere. Its affine generators are explicitly constructed and the Poisson brackets are computed. The defining relations of quantum affine algebra in the sense of the Drinfeld first realization are satisfied at classical level. The relation to the Drinfeld second realization is also discussed including higher conserved charges. Finally we comment on a semiclassic...

  8. On Derivations Of Genetic Algebras

    International Nuclear Information System (INIS)

    A genetic algebra is a (possibly non-associative) algebra used to model inheritance in genetics. In application of genetics this algebra often has a basis corresponding to genetically different gametes, and the structure constant of the algebra encode the probabilities of producing offspring of various types. In this paper, we find the connection between the genetic algebras and evolution algebras. Moreover, we prove the existence of nontrivial derivations of genetic algebras in dimension two

  9. Symmetric structure of field algebra of G-spin models determined by a normal subgroup

    International Nuclear Information System (INIS)

    Let G be a finite group and H a normal subgroup. D(H; G) is the crossed product of C(H) and CG which is only a subalgebra of D(G), the double algebra of G. One can construct a C*-subalgebra FH of the field algebra F of G-spin models, so that FH is a D(H; G)-module algebra, whereas F is not. Then the observable algebra A(H,G) is obtained as the D(H; G)-invariant subalgebra of FH, and there exists a unique C*-representation of D(H; G) such that D(H; G) and A(H,G) are commutants with each other

  10. An algebraic self-training algorithm for multi-channel system identification

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Z. [Auburn Univ., AL (United States); Kennedy, R.A. [Australian National Univ., Canberra (Australia)

    1994-12-31

    In this paper we study the problem of identifying single input-multiple output (SIMO) linear systems that are common in digital communication and control systems. We present an adaptive algorithm for the identification of single input-multiple output linear system. The algorithm is based on a mild co-prime condition and can be implemented as a recursive least square algorithm that has shown quick convergence in simulations. This system identification method can find important applications in digital communications, wideband antenna array processing, and noise control systems.

  11. An algebraic stress model analysis of fully developed turbulent flow in a square duct

    International Nuclear Information System (INIS)

    A numerical experiment has been carried out on a fully developed turbulent flow in a square duct. Special attention is given to clarify the effectiveness of the algebraic stress models treated by Launder-Reece-Rodi (LRR) and Gibson-Launder (GL) in explaining the secondary flow of the second kind. The results favor the LRR model over the GL model in comparison with the experiment. The computational time for an algebraic stress model is not much greater than that of the kε model. (author)

  12. Investigating modularity in the analysis of process algebra models of biochemical systems

    CERN Document Server

    Ciocchetta, Federica; Hillston, Jane; 10.4204/EPTCS.19.4

    2010-01-01

    Compositionality is a key feature of process algebras which is often cited as one of their advantages as a modelling technique. It is certainly true that in biochemical systems, as in many other systems, model construction is made easier in a formalism which allows the problem to be tackled compositionally. In this paper we consider the extent to which the compositional structure which is inherent in process algebra models of biochemical systems can be exploited during model solution. In essence this means using the compositional structure to guide decomposed solution and analysis. Unfortunately the dynamic behaviour of biochemical systems exhibits strong interdependencies between the components of the model making decomposed solution a difficult task. Nevertheless we believe that if such decomposition based on process algebras could be established it would demonstrate substantial benefits for systems biology modelling. In this paper we present our preliminary investigations based on a case study of the phero...

  13. Galois Correspondence in Field Algebra of G-spin Model

    Institute of Scientific and Technical Information of China (English)

    蒋立宁; 郭懋正

    2003-01-01

    @@ A C*-system is a pair (B, G) consisting of a unital C*-algebra B and a continuous group homomorphism α: G → Aut(B) where G is a compact group and Aut(B) the group of automor-phisms of B. If K is a normal subgroup of G and BK = {B∈ B: k(B) = B, k ∈ K}, then BK is a G-invariant C*-subalgebra of B. On the other hand, if A is a G-invariant C*-algebra with BG A B, set G (A) = {g ∈ G: g(A) = A, A ∈ A}, G (A) is a normal subgroup of G. Clearly K G(BK) and we call K Galois closed ifK = G(BK). Similarly, A BG(A) and we call A Galois closed if A = BG(A).

  14. Dual algebraic structures for the two-level pairing model

    International Nuclear Information System (INIS)

    Duality relations are explicitly established relating the Hamiltonians and basis classification schemes associated with the number-conserving unitary and number-nonconserving quasispin algebras for the two-level system with pairing interactions. These relations are obtained in a unified formulation for both bosonic and fermionic systems, with arbitrary and, in general, unequal degeneracies for the two levels. Illustrative calculations are carried out comparing the bosonic and fermionic quantum phase transitions.

  15. Computer algebra and operators

    Science.gov (United States)

    Fateman, Richard; Grossman, Robert

    1989-01-01

    The symbolic computation of operator expansions is discussed. Some of the capabilities that prove useful when performing computer algebra computations involving operators are considered. These capabilities may be broadly divided into three areas: the algebraic manipulation of expressions from the algebra generated by operators; the algebraic manipulation of the actions of the operators upon other mathematical objects; and the development of appropriate normal forms and simplification algorithms for operators and their actions. Brief descriptions are given of the computer algebra computations that arise when working with various operators and their actions.

  16. Performance analysis of a decoding algorithm for algebraic-geometry codes

    DEFF Research Database (Denmark)

    Høholdt, Tom; Jensen, Helge Elbrønd; Nielsen, Rasmus Refslund

    1999-01-01

    that in the typical case, where the error points are "independent," one can prove that the algorithm always fails, that is gives a wrong or no answer, except for high rates where it does much better than expected. This explains the simulation results presented by O'Sullivan at the 1997 ISIT, We also...

  17. Universal Algebras of Hurwitz Numbers

    OpenAIRE

    A. Mironov; Morozov, A; Natanzon, S.

    2009-01-01

    Infinite-dimensional universal Cardy-Frobenius algebra is constructed, which unifies all particular algebras of closed and open Hurwitz numbers and is closely related to the algebra of differential operators, familiar from the theory of Generalized Kontsevich Model.

  18. AN ADA LINEAR ALGEBRA PACKAGE MODELED AFTER HAL/S

    Science.gov (United States)

    Klumpp, A. R.

    1994-01-01

    This package extends the Ada programming language to include linear algebra capabilities similar to those of the HAL/S programming language. The package is designed for avionics applications such as Space Station flight software. In addition to the HAL/S built-in functions, the package incorporates the quaternion functions used in the Shuttle and Galileo projects, and routines from LINPAK that solve systems of equations involving general square matrices. Language conventions in this package follow those of HAL/S to the maximum extent practical and minimize the effort required for writing new avionics software and translating existent software into Ada. Valid numeric types in this package include scalar, vector, matrix, and quaternion declarations. (Quaternions are fourcomponent vectors used in representing motion between two coordinate frames). Single precision and double precision floating point arithmetic is available in addition to the standard double precision integer manipulation. Infix operators are used instead of function calls to define dot products, cross products, quaternion products, and mixed scalar-vector, scalar-matrix, and vector-matrix products. The package contains two generic programs: one for floating point, and one for integer. The actual component type is passed as a formal parameter to the generic linear algebra package. The procedures for solving systems of linear equations defined by general matrices include GEFA, GECO, GESL, and GIDI. The HAL/S functions include ABVAL, UNIT, TRACE, DET, INVERSE, TRANSPOSE, GET, PUT, FETCH, PLACE, and IDENTITY. This package is written in Ada (Version 1.2) for batch execution and is machine independent. The linear algebra software depends on nothing outside the Ada language except for a call to a square root function for floating point scalars (such as SQRT in the DEC VAX MATHLIB library). This program was developed in 1989, and is a copyrighted work with all copyright vested in NASA.

  19. Max-plus algebra models of queueing networks

    OpenAIRE

    Krivulin, Nikolai K.

    2012-01-01

    A class of queueing networks which may have an arbitrary topology, and consist of single-server fork-join nodes with both infinite and finite buffers is examined to derive a representation of the network dynamics in terms of max-plus algebra. For the networks, we present a common dynamic state equation which relates the departure epochs of customers from the network nodes in an explicit vector form determined by a state transition matrix. It is shown how the matrices inherent in particular ne...

  20. The Algebraic Cluster Model: Structure of 16O

    CERN Document Server

    Bijker, R

    2016-01-01

    We discuss an algebraic treatment of four-body clusters which includes both continuous and discrete symmetries. In particular, tetrahedral configurations with T(d) symmetry are analyzed with respect to the energy spectrum, transition form factors and B(EL) values. It is concluded that the low-lying spectrum of 16O can be described by four alpha-particles at the vertices of a regular tetrahedron, not as a rigid structure but rather a more floppy structure with relatively large rotation-vibration interactions and Coriolis forces.

  1. Mathematical modelling in engineering: A proposal to introduce linear algebra concepts

    Directory of Open Access Journals (Sweden)

    Andrea Dorila Cárcamo

    2016-03-01

    Full Text Available The modern dynamic world requires that basic science courses for engineering, including linear algebra, emphasize the development of mathematical abilities primarily associated with modelling and interpreting, which aren´t limited only to calculus abilities. Considering this, an instructional design was elaborated based on mathematic modelling and emerging heuristic models for the construction of specific linear algebra concepts:  span and spanning set. This was applied to first year engineering students. Results suggest that this type of instructional design contributes to the construction of these mathematical concepts and can also favour first year engineering students understanding of key linear algebra concepts and potentiate the development of higher order skills.

  2. Hopf Algebra Structure of a Model Quantum Field Theory

    CERN Document Server

    Solomon, A I; Blasiak, P; Horzela, A; Penson, K A

    2006-01-01

    Recent elegant work on the structure of Perturbative Quantum Field Theory (PQFT) has revealed an astonishing interplay between analysis(Riemann Zeta functions), topology (Knot theory), combinatorial graph theory (Feynman Diagrams) and algebra (Hopf structure). The difficulty inherent in the complexities of a fully-fledged field theory such as PQFT means that the essential beauty of the relationships between these areas can be somewhat obscured. Our intention is to display some, although not all, of these structures in the context of a simple zero-dimensional field theory; i.e. a quantum theory of non-commuting operators which do not depend on spacetime. The combinatorial properties of these boson creation and annihilation operators, which is our chosen example, may be described by graphs, analogous to the Feynman diagrams of PQFT, which we show possess a Hopf algebra structure. Our approach is based on the partition function for a boson gas. In a subsequent note in these Proceedings we sketch the relationship...

  3. On the 2D zero modes' algebra of the SU(n) WZNW model

    CERN Document Server

    Hadjiivanov, Ludmil

    2014-01-01

    A quantum group covariant extension of the chiral parts of the Wess-Zumino-Novikov-Witten model on a compact Lie group G gives rise to two matrix algebras with non-commutative entries. These are generated by "chiral zero modes" which combine in the 2D model into "Q-operators" which encode information about the internal symmetry and the fusion ring. We review earlier results about the SU(n) WZNW Q-algebra and its Fock representation for n=2 and display the first steps towards their generalization to higher n.

  4. U(2) algebraic model applied to stretching vibrational spectra of tetrahedral molecules

    CERN Document Server

    Hou, X W; Hou, Xi-Wen; Ma, Zhong-Qi

    1998-01-01

    The highly excited stretching vibrational energy levels and the intensities of infrared transitions in tetrahedral molecules are studied in a U(2) algebraic model. Its applications to silane and silicon tetrafluoride are presented with smaller standard deviations than those of other models.

  5. The Model Method: Singapore Children's Tool for Representing and Solving Algebraic Word Problems

    Science.gov (United States)

    Ng, Swee Fong; Lee, Kerry

    2009-01-01

    Solving arithmetic and algebraic word problems is a key component of the Singapore elementary mathematics curriculum. One heuristic taught, the model method, involves drawing a diagram to represent key information in the problem. We describe the model method and a three-phase theoretical framework supporting its use. We conducted 2 studies to…

  6. Construction of the Model of the Lambda Calculus System with Algebraic Operators

    Institute of Scientific and Technical Information of China (English)

    陆汝占; 张政; 等

    1991-01-01

    A lambda system with algebraic operators,Lambda-plus system,is introduced.After giving the definitions of the system,we present a sufficient condition for formulating a model of the system.Finally,a model of such system is constructed.

  7. Permutation invariant algebras, a Fock space realization and the Calogero model

    International Nuclear Information System (INIS)

    We study permutation invariant oscillator algebras and their Fock space representations using three equivalent techniques, i.e. (i) a normally ordered expansion in creation and annihilation operators, (ii) the action of annihilation operators on monomial states in Fock space and (iii) Gram matrices of inner products in Fock space. We separately discuss permutation invariant algebras which possess hermitean number operators and permutation invariant algebras which possess non-hermitean number operators. The results of a general analysis are applied to the SM-extended Heisenberg algebra, underlying the M-body Calogero model. Particular attention is devoted to the analysis of Gram matrices for the Calogero model. We discuss their structure, eigenvalues and eigenstates. We obtain a general condition for positivity of eigenvalues, meaning that all norms of states in Fock space are positive if this condition is satisfied. We find a universal critical point at which the reduction of the physical degrees of freedom occurs. We construct dual operators, leading to the ordinary Heisenberg algebra of free Bose oscillators. From the Fock-space point of view, we briefly discuss the existence of a mapping from the Calogero oscillators to the free Bose oscillators and vice versa. (orig.)

  8. Algebraic formulation of duality

    International Nuclear Information System (INIS)

    Two dimensional lattice spin (chiral) models over (possibly non-abelian) compact groups are formulated in terms of a generalized Pauli algebra. Such models over cyclic groups are written in terms of the generalized Clifford algebra. An automorphism of this algebra is shown to exist and to lead to the duality transformation

  9. Non-freely generated W-algebras and construction of N=2 super W-algebras

    International Nuclear Information System (INIS)

    Firstly, we investigate the origin of the bosonic W-algebras W(2, 3, 4, 5), W(2, 4, 6) and W(2, 4, 6) found earlier by direct construction. We present a coset construction for all three examples leading to a new type of finitely, non-freely generated quantum W-algebras, which we call unifying W-algebras. Secondly, we develop a manifest covariant formalism to construct N = 2 super W-algebras explicitly on a computer. Applying this algorithm enables us to construct the first four examples of N = 2 super W-algebras with two generators and the N = 2 super W4 algebra involving three generators. The representation theory of the former ones shows that all examples could be divided into four classes, the largest one containing the N = 2 special type of spectral flow algebras. Besides the W-algebra of the CP(3) Kazama-Suzuki coset model, the latter example with three generators discloses a second solution which could also be explained as a unifying W-algebra for the CP(n) models. (orig.)

  10. Graded Poisson-Sigma models and dilaton-deformed 2D supergravity algebra

    International Nuclear Information System (INIS)

    Supergravity extensions of generic 2d gravity theories obtained from the graded Poisson-Sigma model (gPSM) approach show a large degree of ambiguity. On the other hand, obstructions may reduce the allowed range of fields as given by the bosonic theory, or even prohibit any extension in certain cases. In our present work we relate the finite W-algebras inherent in the gPSM algebra of constraints to supergravity algebras (Neuveu-Schwarz or Ramond algebras resp.), deformed by the presence of the dilaton field. With very straightforward and natural assumptions on them - like the one linking the anti-commutator of certain fermionic charges to the Hamiltonian constraint without deformation - we are able not only to remove the ambiguities but, at the same time, the singularities referred to above. Thus all especially interesting bosonic models (spherically reduced gravity, the Jackiw-Teitelboim model etc.) under these conditions possess a unique fermionic extension and are free from new singularities. The superspace supergravity model of Howe is found as a special case of this supergravity action. For this class of models the relation between bosonic potential and prepotential does not introduce obstructions as well. (author)

  11. A stochastic extension of the explicit algebraic subgrid-scale models

    International Nuclear Information System (INIS)

    The explicit algebraic subgrid-scale (SGS) stress model (EASM) of Marstorp et al. [“Explicit algebraic subgrid stress models with application to rotating channel flow,” J. Fluid Mech. 639, 403–432 (2009)] and explicit algebraic SGS scalar flux model (EASFM) of Rasam et al. [“An explicit algebraic model for the subgrid-scale passive scalar flux,” J. Fluid Mech. 721, 541–577 (2013)] are extended with stochastic terms based on the Langevin equation formalism for the subgrid-scales by Marstorp et al. [“A stochastic subgrid model with application to turbulent flow and scalar mixing,” Phys. Fluids 19, 035107 (2007)]. The EASM and EASFM are nonlinear mixed and tensor eddy-diffusivity models, which improve large eddy simulation (LES) predictions of the mean flow, Reynolds stresses, and scalar fluxes of wall-bounded flows compared to isotropic eddy-viscosity and eddy-diffusivity SGS models, especially at coarse resolutions. The purpose of the stochastic extension of the explicit algebraic SGS models is to further improve the characteristics of the kinetic energy and scalar variance SGS dissipation, which are key quantities that govern the small-scale mixing and dispersion dynamics. LES of turbulent channel flow with passive scalar transport shows that the stochastic terms enhance SGS dissipation statistics such as length scale, variance, and probability density functions and introduce a significant amount of backscatter of energy from the subgrid to the resolved scales without causing numerical stability problems. The improvements in the SGS dissipation predictions in turn enhances the predicted resolved statistics such as the mean scalar, scalar fluxes, Reynolds stresses, and correlation lengths. Moreover, the nonalignment between the SGS stress and resolved strain-rate tensors predicted by the EASM with stochastic extension is in much closer agreement with direct numerical simulation data

  12. Application of non-commutative algebra to a soluble fermionic model

    International Nuclear Information System (INIS)

    We explore the properties of the non-commutative Grassmann algebra to obtain the high-temperature expansion of the grand canonical partition function for self-interacting fermionic systems. As an application, we consider the anharmonic fermionic oscillator, the simplest model in Quantum Mechanics with self-interacting fermions that is exactly soluble. The knowledge of the exact expression for its grand canonical partition function enables us to check the β-expansion obtained using our Grassmann-algebra-based technique. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  13. Left Artinian Algebraic Algebras

    Institute of Scientific and Technical Information of China (English)

    S. Akbari; M. Arian-Nejad

    2001-01-01

    Let R be a left artinian central F-algebra, T(R) = J(R) + [R, R],and U(R) the group of units of R. As one of our results, we show that, if R is algebraic and char F = 0, then the number of simple components of -R = R/J(R)is greater than or equal to dimF R/T(R). We show that, when char F = 0 or F is uncountable, R is algebraic over F if and only if [R, R] is algebraic over F. As another approach, we prove that R is algebraic over F if and only if the derived subgroup of U(R) is algebraic over F. Also, we present an elementary proof for a special case of an old question due to Jacobson.

  14. Algebraic Bethe ansatz for the gl(1|2) generalized model: II. the three gradings

    International Nuclear Information System (INIS)

    The algebraic Bethe ansatz can be performed rather abstractly for whole classes of models sharing the same R-matrix, the only prerequisite being the existence of an appropriate pseudo vacuum state. Here we perform the algebraic Bethe ansatz for all models with 9 x 9, rational, gl(1|2) invariant R-matrix and all three possibilities of choosing the grading. Our Bethe ansatz solution applies, for instance, to the supersymmetric t-J model, the supersymmetric U model and a number of interesting impurity models. It may be extended to obtain the quantum transfer matrix spectrum for this class of models. The properties of a specific model enter the Bethe ansatz solution (i.e. the expression for the transfer matrix eigenvalue and the Bethe ansatz equations) through the three pseudo vacuum eigenvalues of the diagonal elements of the monodromy matrix which in this context are called the parameters of the model

  15. CSOS models descending from chiral Potts models: degeneracy of the eigenspace and loop algebra

    Science.gov (United States)

    Au-Yang, Helen; Perk, Jacques H. H.

    2016-04-01

    Monodromy matrices of the {{\\boldsymbol{τ }}}2\\phantom{^{\\prime }} model are known to satisfy a Yang-Baxter equation with a six-vertex R-matrix as the intertwiner. The commutation relations of the elements of the monodromy matrices are completely determined by this R-matrix. We show the reason why in the superintegrable case the eigenspace is degenerate, but not in the general case. We then show that the eigenspaces of special CSOS models descending from the chiral Potts model are also degenerate. The existence of an L({{sl}}2) quantum loop algebra (or subalgebra) in these models is established by showing that the Serre relations hold for the generators. The highest weight polynomial (or the Drinfeld polynomial) of the representation is obtained by using the method of Baxter for the superintegrable case. As a byproduct, the eigenvalues of all such CSOS models are given explicitly.

  16. Construction of linear models: A framework based on commutative Jordan algebras

    Science.gov (United States)

    Covas, R.; Carvalho, F.

    2016-06-01

    We show how to obtain the necessary structures for statistical analysis of the folllowing orthogonal models Y˜(1 μ +∑i Xiβi ,∑j σj2Mj+σ2I ) . These structures rely on the existence of Jordan algebras, in the sequence of [24], [8], [12], [9], [5] and [10].

  17. Shape Optimization for Navier-Stokes Equations with Algebraic Turbulence Model: Existence Analysis

    Czech Academy of Sciences Publication Activity Database

    Bulíček, M.; Haslinger, J.; Málek, J.; Stebel, Jan

    2009-01-01

    Roč. 60, č. 2 (2009), s. 185-212. ISSN 0095-4616 R&D Projects: GA MŠk LC06052 Institutional research plan: CEZ:AV0Z10190503 Keywords : optimal shape design * paper machine headbox * incompressible non-Newtonian fluid * algebraic turbulence model * outflow boundary condition Subject RIV: BA - General Mathematics Impact factor: 0.757, year: 2009

  18. Algebraic Bethe ansatz for 19-vertex models with upper triangular K-matrices

    International Nuclear Information System (INIS)

    By means of an algebraic Bethe ansatz approach, we study the Zamolodchikov–Fateev and Izergin–Korepin vertex models with non-diagonal boundaries, characterized by reflection matrices with an upper triangular form. Generalized Bethe vectors are used to diagonalize the associated transfer matrix. The eigenvalues as well as the Bethe equations are presented. (paper)

  19. Algebraic Bethe ansatz for scalar products in SU(3)-invariant integrable models

    CERN Document Server

    Belliard, S; Ragoucy, E; Slavnov, N A

    2012-01-01

    We study SU(3)-invariant integrable models solvable by nested algebraic Bethe ansatz. We obtain a determinant representation for particular case of scalar products of Bethe vectors. This representation can be used for the calculation of form factors and correlation functions of XXX SU(3)-invariant Heisenberg chain.

  20. Algebraic Bethe Ansatz for O(2N) sigma models with integrable diagonal boundaries

    CERN Document Server

    Gombor, Tamas

    2015-01-01

    The finite volume problem of O(2N) sigma models with integrable diagonal boundaries on a finite interval is investigated. The double row transfer matrix is diagonalized by Algebraic Bethe Ansatz. The boundary Bethe Yang equations for the particle rapidities and the accompanying Bethe Ansatz equations are derived.

  1. Mathematical Modelling in Engineering: An Alternative Way to Teach Linear Algebra

    Science.gov (United States)

    Domínguez-García, S.; García-Planas, M. I.; Taberna, J.

    2016-01-01

    Technological advances require that basic science courses for engineering, including Linear Algebra, emphasize the development of mathematical strengths associated with modelling and interpretation of results, which are not limited only to calculus abilities. Based on this consideration, we have proposed a project-based learning, giving a dynamic…

  2. Priority in Process Algebras

    Science.gov (United States)

    Cleaveland, Rance; Luettgen, Gerald; Natarajan, V.

    1999-01-01

    This paper surveys the semantic ramifications of extending traditional process algebras with notions of priority that allow for some transitions to be given precedence over others. These enriched formalisms allow one to model system features such as interrupts, prioritized choice, or real-time behavior. Approaches to priority in process algebras can be classified according to whether the induced notion of preemption on transitions is global or local and whether priorities are static or dynamic. Early work in the area concentrated on global pre-emption and static priorities and led to formalisms for modeling interrupts and aspects of real-time, such as maximal progress, in centralized computing environments. More recent research has investigated localized notions of pre-emption in which the distribution of systems is taken into account, as well as dynamic priority approaches, i.e., those where priority values may change as systems evolve. The latter allows one to model behavioral phenomena such as scheduling algorithms and also enables the efficient encoding of real-time semantics. Technically, this paper studies the different models of priorities by presenting extensions of Milner's Calculus of Communicating Systems (CCS) with static and dynamic priority as well as with notions of global and local pre- emption. In each case the operational semantics of CCS is modified appropriately, behavioral theories based on strong and weak bisimulation are given, and related approaches for different process-algebraic settings are discussed.

  3. Forward error correction based on algebraic-geometric theory

    CERN Document Server

    A Alzubi, Jafar; M Chen, Thomas

    2014-01-01

    This book covers the design, construction, and implementation of algebraic-geometric codes from Hermitian curves. Matlab simulations of algebraic-geometric codes and Reed-Solomon codes compare their bit error rate using different modulation schemes over additive white Gaussian noise channel model. Simulation results of Algebraic-geometric codes bit error rate performance using quadrature amplitude modulation (16QAM and 64QAM) are presented for the first time and shown to outperform Reed-Solomon codes at various code rates and channel models. The book proposes algebraic-geometric block turbo codes. It also presents simulation results that show an improved bit error rate performance at the cost of high system complexity due to using algebraic-geometric codes and Chase-Pyndiah’s algorithm simultaneously. The book proposes algebraic-geometric irregular block turbo codes (AG-IBTC) to reduce system complexity. Simulation results for AG-IBTCs are presented for the first time.

  4. Reduced Chern-Simons Quiver Theories and Cohomological 3-Algebra Models

    CERN Document Server

    DeBellis, Joshua

    2013-01-01

    We study the BPS spectrum and vacuum moduli spaces in dimensional reductions of Chern-Simons-matter theories with N>=2 supersymmetry to zero dimensions. Our main example is a matrix model version of the ABJM theory which we relate explicitly to certain reduced 3-algebra models. We find the explicit maps from Chern-Simons quiver matrix models to dual IKKT matrix models. We address the problem of topologically twisting the ABJM matrix model, and along the way construct a new twist of the IKKT model. We construct a cohomological matrix model whose partition function localizes onto a moduli space specified by 3-algebra relations which live in the double of the conifold quiver. It computes an equivariant index enumerating framed BPS states with specified R-charges which can be expressed as a combinatorial sum over certain filtered pyramid partitions.

  5. Kink states in P(φ)2-models. (An algebraic approach)

    International Nuclear Information System (INIS)

    Several two-dimensional quantum field theory models have more than one vacuum state. Familiar examples are the Sine-Gordon and the φ24-model. It is known that in these models there are also states, called kink states, which interpolate different vacua. A general construction scheme for kink states in the framework of algebraic quantum field theory is developed in a previous paper. However, for the application of this method, the crucial condition is the split property for wedge algebras in the vacuum representations of the considered models. It is believed that the vacuum representations of P(φ)2-models fulfill this condition, but a rigorous proof is only known for the massive free scalar field. Therefore, we investigate in a construction of kink states which can directly be applied to P(φ)2-model, by making use of the properties of the dynamic of a P(φ)2-model. (orig.)

  6. Evaluation of global synchronization for iterative algebra algorithms on many-core

    KAUST Repository

    ul Hasan Khan, Ayaz

    2015-06-01

    © 2015 IEEE. Massively parallel computing is applied extensively in various scientific and engineering domains. With the growing interest in many-core architectures and due to the lack of explicit support for inter-block synchronization specifically in GPUs, synchronization becomes necessary to minimize inter-block communication time. In this paper, we have proposed two new inter-block synchronization techniques: 1) Relaxed Synchronization, and 2) Block-Query Synchronization. These schemes are used in implementing numerical iterative solvers where computation/communication overlapping is one used optimization to enhance application performance. We have evaluated and analyzed the performance of the proposed synchronization techniques using Jacobi Iterative Solver in comparison to the state of the art inter-block lock-free synchronization techniques. We have achieved about 1-8% performance improvement in terms of execution time over lock-free synchronization depending on the problem size and the number of thread blocks. We have also evaluated the proposed algorithm on GPU and MIC architectures and obtained about 8-26% performance improvement over the barrier synchronization available in OpenMP programming environment depending on the problem size and number of cores used.

  7. Modeling and Engineering Algorithms for Mobile Data

    DEFF Research Database (Denmark)

    Blunck, Henrik; Hinrichs, Klaus; Sondern, Joëlle; Vahrenhold, Jan

    In this paper, we present an object-oriented approach to modeling mobile data and algorithms operating on such data. Our model is general enough to capture any kind of continuous motion while at the same time allowing for encompassing algorithms optimized for specific types of motion. Such motion...

  8. Quantum Lie algebra solitons

    International Nuclear Information System (INIS)

    We construct a special type of quantum soliton solutions for quantized affine Toda models. The elements of the principal Heisenberg subalgebra in the affinised quantum Lie algebra are found. Their eigenoperators inside the quantized universal enveloping algebra for an affine Lie algebra are constructed to generate quantum soliton solutions

  9. Clifford Algebras and Graphs

    OpenAIRE

    Khovanova, Tanya

    2008-01-01

    I show how to associate a Clifford algebra to a graph. I describe the structure of these Clifford graph algebras and provide many examples and pictures. I describe which graphs correspond to isomorphic Clifford algebras and also discuss other related sets of graphs. This construction can be used to build models of representations of simply-laced compact Lie groups.

  10. Combinatorics of solvable lattice models, and modular representations of Hecke algebras

    CERN Document Server

    Foda, O E; Okado, M; Thibon, J Y; Welsh, Trevor A; Foda, Omar; Leclerc, Bernard; Okado, Masato; Thibon, Jean-Yves; Welsh, Trevor A.

    1997-01-01

    We review and motivate recently-observed relationships between exactly solvable lattice models and modular representations of Hecke algebras. Firstly, we describe how the set of $n$-regular partitions label both of the following classes of objects: 1. The spectrum of unrestricted solid-on-solid lattice models based on level-1 representations of the affine algebras $\\sl_n$, 2. The irreducible representations of type-A Hecke algebras at roots of unity: $H_m(\\sqrt[n]{1})$. Secondly, we show that a certain subset of the $n$-regular partitions label both of the following classes of objects: 1. The spectrum of restricted solid-on-solid lattice models based on cosets of affine algebras $(sl(n)^_1 \\times sl(n)^_1)/ sl(n)^_2$. 2. Jantzen-Seitz (JS) representations of $H_m(\\sqrt[n]{1})$: irreducible representations that remain irreducible under restriction to $H_{m-1}(\\sqrt[n]{1})$. Using the above relationships, we characterise the JS representations of $H_m(\\sqrt[n]{1})$ and show that the generating series that count...

  11. Abstract algebra

    CERN Document Server

    Deskins, W E

    1996-01-01

    This excellent textbook provides undergraduates with an accessible introduction to the basic concepts of abstract algebra and to the analysis of abstract algebraic systems. These systems, which consist of sets of elements, operations, and relations among the elements, and prescriptive axioms, are abstractions and generalizations of various models which evolved from efforts to explain or discuss physical phenomena.In Chapter 1, the author discusses the essential ingredients of a mathematical system, and in the next four chapters covers the basic number systems, decompositions of integers, diop

  12. Development of an explicit algebraic turbulence model for buoyant flows – Part 1: DNS analysis

    International Nuclear Information System (INIS)

    Highlights: • DNS analysis of channel flow for forced, mixed and natural convection regime. • Examination of algebraic turbulenc model main features with buoyancy. • Investigation of the weak equilibrium assumption for buoyant flows. • Assessment of the redistribution term model for EARSM with buoyancy effect. • Assessment of the pressure scrambling term model for EAHFM. -- Abstract: An analysis of DNS databases of vertical plane channel flow for forced, mixed and natural convection is proposed. This analysis aims to assess the main features needed to develop an algebraic model for buoyant flows. First, the weak equilibrium assumption, at the root of algebraic models, is investigated. This hypothesis is shown to fail near the velocity maximum and close to the walls but remains valid otherwise, whatever the convection regime. The models for the redistribution term and the pressure scrambling term are then analyzed on the same configurations. A linear form of the Speziale et al. (1991) model is retained for the redistribution term. No model for the pressure scrambling term is fully satisfactory; nevertheless some models are recommended. The buoyant contributions to the pressure term are investigated. Finally, the generalized gradient diffusion hypothesis, which could be used to model the turbulent heat fluxes in order to avoid the coupling with the Reynolds stresses, is shown to be inaccurate

  13. A new class of Matrix Models arising from the W-infinity Algebra

    OpenAIRE

    Herce, Henry D.; Zemba, Guillermo R.

    2002-01-01

    We present a new class of hermitian one-matrix models originated in the W-infinity algebra: more precisely, the polynomials defining the W-infinity generators in their fermionic bilinear form are shown to expand the orthogonal basis of a class of random hermitian matrix models. The corresponding potentials are given, and the thermodynamic limit interpreted in terms of a simple plasma picture. The new matrix models can be successfully applied to the full bosonization of interesting one-dimensi...

  14. Optical systolic solutions of linear algebraic equations

    Science.gov (United States)

    Neuman, C. P.; Casasent, D.

    1984-01-01

    The philosophy and data encoding possible in systolic array optical processor (SAOP) were reviewed. The multitude of linear algebraic operations achievable on this architecture is examined. These operations include such linear algebraic algorithms as: matrix-decomposition, direct and indirect solutions, implicit and explicit methods for partial differential equations, eigenvalue and eigenvector calculations, and singular value decomposition. This architecture can be utilized to realize general techniques for solving matrix linear and nonlinear algebraic equations, least mean square error solutions, FIR filters, and nested-loop algorithms for control engineering applications. The data flow and pipelining of operations, design of parallel algorithms and flexible architectures, application of these architectures to computationally intensive physical problems, error source modeling of optical processors, and matching of the computational needs of practical engineering problems to the capabilities of optical processors are emphasized.

  15. Matlab linear algebra

    CERN Document Server

    Lopez, Cesar

    2014-01-01

    MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Linear Algebra introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. In addition to giving an introduction to

  16. Position Automata for Kleene Algebra with Tests

    Directory of Open Access Journals (Sweden)

    A. Silva

    2012-01-01

    Full Text Available Kleene algebra with tests (KAT is an equational system that combines Kleene and Boolean algebras. One can model basic programming constructs and assertions in KAT, which allowed for its application in compiler optimization, program transformation and dataflow analysis. To provide semantics for KAT expressions, Kozen first introduced emph{automata on guarded strings}, showing that the regular sets of guarded strings plays the same role in KAT as regular languages play in Kleene algebra. Recently, Kozen described an elegant algorithm, based on ``derivatives'', to construct a deterministic automaton that accepts the guarded strings denoted by a KAT expression. This algorithm generalizes Brzozowski's algorithm for regular expressions and inherits its inefficiency arising from the explicit computation of derivatives. In the context of classical regular expressions, many efficient algorithms to compile expressions to automata have been proposed. One of those algorithms was devised by Berry and Sethi in the 80's (we shall refer to it as Berry-Sethi construction/algorithm, but in the literature it is also referred to as position or Glushkov automata algorithm. In this paper, we show how the Berry-Sethi algorithm can be used to compile a $KAT$ expression to an automaton on guarded strings. Moreover, we propose a new automata model for KAT expressions and adapt the construction of Berry and Sethi to this new model.

  17. Algebraic approach to electro-optic modulation of light: Exactly solvable multimode quantum model

    CERN Document Server

    Miroshnichenko, George P; Trifanov, Alexander I; Gleim, Artur V

    2016-01-01

    We theoretically study electro-optic light modulation based on the quantum model where the linear electro-optic effect and the externally applied microwave field result in the interaction between optical cavity modes. The model assumes that the number of interacting modes is finite and effects of the mode overlapping coefficient on the strength of the intermode interaction can be taken into account through dependence of the coupling coefficient on the mode characteristics. We show that, under certain conditions, the model is exactly solvable and, in the semiclassical approximation where the microwave field is treated as a classical mode, can be analyzed using the technique of the Jordan mappings for the su(2) Lie algebra. Analytical results are applied to study effects of light modulation on the frequency dependence of the photon counting rate. We also establish the conditions of validity of the semiclassical approximation by applying the methods of polynomially deformed Lie algebras for analysis of the model...

  18. A Generalized Moebius Transform of Games on MV-algebras and Its Application to a Cimmino-type Algorithm for the Core

    Czech Academy of Sciences Publication Activity Database

    Kroupa, Tomáš

    Providence, Rhode Island : American Mathematical Society, 2012 - (Reich, S.; Zaslavski, A.), s. 139-158 ISBN 978-0-8218-6908-6. - (Contemporary Mathematics. 568) R&D Projects: GA MŠk 1M0572; GA ČR GA201/09/1957; GA ČR GA201/09/1891 Institutional research plan: CEZ:AV0Z10750506 Institutional support: RVO:67985556 Keywords : coalition game * MV-algebra * Moebius transform Subject RIV: BA - General Mathematics http://library.utia.cas.cz/separaty/2012/MTR/kroupa - a generalized moebius transform of game s on mv-algebras and its application to a cimmino-type algorithm for the core.pdf

  19. Composing Scalable Nonlinear Algebraic Solvers

    OpenAIRE

    Brune, Peter R.; Knepley, Matthew G.; Smith, Barry F.; Tu, Xuemin

    2016-01-01

    Most efficient linear solvers use composable algorithmic components, with the most common model being the combination of a Krylov accelerator and one or more preconditioners. A similar set of concepts may be used for nonlinear algebraic systems, where nonlinear composition of different nonlinear solvers may significantly improve the time to solution. We describe the basic concepts of nonlinear composition and preconditioning and present a number of solvers applicable to nonlinear partial diff...

  20. An algebraic stress/flux model for two-phase turbulent flow

    International Nuclear Information System (INIS)

    An algebraic stress model (ASM) for turbulent Reynolds stress and a flux model for turbulent heat flux are proposed for two-phase bubbly and slug flows. These mathematical models are derived from the two-phase transport equations for Reynolds stress and turbulent heat flux, and provide Cμ, a turbulent constant which defines the level of eddy viscosity, as a function of the interfacial terms. These models also include the effect of heat transfer. When the interfacial drag terms and the interfacial momentum transfer terms are absent, the model reduces to a single-phase model used in the literature

  1. Lectures on algebraic statistics

    CERN Document Server

    Drton, Mathias; Sullivant, Seth

    2009-01-01

    How does an algebraic geometer studying secant varieties further the understanding of hypothesis tests in statistics? Why would a statistician working on factor analysis raise open problems about determinantal varieties? Connections of this type are at the heart of the new field of "algebraic statistics". In this field, mathematicians and statisticians come together to solve statistical inference problems using concepts from algebraic geometry as well as related computational and combinatorial techniques. The goal of these lectures is to introduce newcomers from the different camps to algebraic statistics. The introduction will be centered around the following three observations: many important statistical models correspond to algebraic or semi-algebraic sets of parameters; the geometry of these parameter spaces determines the behaviour of widely used statistical inference procedures; computational algebraic geometry can be used to study parameter spaces and other features of statistical models.

  2. Algebraic geometry

    CERN Document Server

    Lefschetz, Solomon

    2012-01-01

    An introduction to algebraic geometry and a bridge between its analytical-topological and algebraical aspects, this text for advanced undergraduate students is particularly relevant to those more familiar with analysis than algebra. 1953 edition.

  3. Surfaces immersed in su(N+1) Lie algebras obtained from the CPN sigma models

    International Nuclear Information System (INIS)

    We study some geometrical aspects of two-dimensional orientable surfaces arising from the study of CPN sigma models. To this aim we employ an identification of RN(N+2) with the Lie algebra su(N+1) by means of which we construct a generalized Weierstrass formula for immersion of such surfaces. The structural elements of the surface like its moving frame, the Gauss-Weingarten and the Gauss-Codazzi-Ricci equations are expressed in terms of the solution of the CPN model defining it. Further, the first and second fundamental forms, the Gaussian curvature, the mean curvature vector, the Willmore functional and the topological charge of surfaces are expressed in terms of this solution. We present detailed implementation of these results for surfaces immersed in su(2) and su(3) Lie algebras

  4. The relationship between the interacting boson model and the algebraic version of Bohr's collective model in its triaxial limit

    International Nuclear Information System (INIS)

    Recent developments and applications of an algebraic version of Bohr's collective model, known as the algebraic collective model (ACM), have shown that fully converged calculations can be performed for a large range of Hamiltonians. Examining the algebraic structure underlying the Bohr model (BM) has also clarified its relationship with the interacting boson model (IBM), with which it has related solvable limits and corresponding dynamical symmetries. In particular, the algebraic structure of the IBM is obtained as a compactification of the BM and conversely the BM is regained in various contraction limits of the IBM. In a previous paper, corresponding contractions were identified and confirmed numerically for axially-symmetric states of relatively small deformation. In this paper, we extend the comparisons to realistic deformations and compare results of the two models in the rotor-vibrator limit. These models describe rotations and vibrations about an axially symmetric prolate or oblate rotor, and rotations and vibrations of a triaxial rotor. It is determined that most of the standard results of the BM can be obtained as contraction limits of the IBM in its U(5)-SO(6) dynamical symmetries.

  5. Shape optimization for Navier-Stokes equations with algebraic turbulence model : numerical analysis and computation

    Czech Academy of Sciences Publication Activity Database

    Haslinger, J.; Stebel, Jan

    2011-01-01

    Roč. 63, č. 2 (2011), s. 277-308. ISSN 0095-4616 R&D Projects: GA MŠk LC06052 Institutional research plan: CEZ:AV0Z10190503 Keywords : optimal shape design * paper machine headbox * incompressible non-Newtonian fluid * algebraic turbulence model Subject RIV: BA - General Mathematics Impact factor: 0.952, year: 2011 http://link.springer.com/article/10.1007%2Fs00245-010-9121-x

  6. Another algebraic variational principle for the spectral curve of matrix models

    CERN Document Server

    Eynard, B

    2014-01-01

    We propose an alternative variational principle whose critical point is the algebraic plane curve associated to a matrix model (the spectral curve, i.e. the large $N$ limit of the resolvent). More generally, we consider a variational principle that is equivalent to the problem of finding a plane curve with given asymptotics and given cycle integrals. This variational principle is not given by extremization of the energy, but by the extremization of an "entropy".

  7. Chaos Control in Three Dimensional Cancer Model by State Space Exact Linearization Based on Lie Algebra

    OpenAIRE

    Mohammad Shahzad

    2016-01-01

    This study deals with the control of chaotic dynamics of tumor cells, healthy host cells, and effector immune cells in a chaotic Three Dimensional Cancer Model (TDCM) by State Space Exact Linearization (SSEL) technique based on Lie algebra. A non-linear feedback control law is designed which induces a coordinate transformation thereby changing the original chaotic TDCM system into a controlled one linear system. Numerical simulation has been carried using Mathematica that witness the robustne...

  8. RSOS models and Jantzen-Seitz representations of Hecke algebras at roots of unity

    OpenAIRE

    Foda, Omar; Leclerc, Bernard; Okado, Masato; Thibon, Jean-Yves; Welsh, Trevor A.

    1997-01-01

    A special family of partitions occurs in two apparently unrelated contexts: the evaluation of 1-dimensional configuration sums of certain RSOS models, and the modular representation theory of symmetric groups or their Hecke algebras $H_m$. We provide an explanation of this coincidence by showing how the irreducible $H_m$-modules which remain irreducible under restriction to $H_{m-1}$ (Jantzen-Seitz modules) can be determined from the decomposition of a tensor product of representations of aff...

  9. Algebraic and relational models for a system based on a poset of two elements

    OpenAIRE

    Iturrioz, Luisa

    2014-01-01

    The aim of this paper is to present a very simple set of conditions, necessary for the management of knowledge of a poset $T$ of two agents, which are partially ordered by the capabilities available in the system. We build up a formal system and we elaborate suitable semantic models in order to derive information from the poset. The system is related to three-valued Heyting algebras with Boolean operators.

  10. On the algebraic structure of self-dual gauge fields and sigma models

    International Nuclear Information System (INIS)

    An extensive and detailed analysis of self-dual Gauge Fields, in particular with axial symmetry, is presented, culminating in a purely algebraic procedure to generate solutions. The method which is particularly suited for the construction of multimonopole solutions for a theory with arbitrary G, is also applicable to a wide class of nonlinear sigma models. The relevant symmetries as well as the associated linear problems which underly the exact solubility of the problem, are constructed and discussed in detail. (author)

  11. Lie algebras and applications

    CERN Document Server

    Iachello, Francesco

    2015-01-01

    This course-based primer provides an introduction to Lie algebras and some of their applications to the spectroscopy of molecules, atoms, nuclei and hadrons. In the first part, it concisely presents the basic concepts of Lie algebras, their representations and their invariants. The second part includes a description of how Lie algebras are used in practice in the treatment of bosonic and fermionic systems. Physical applications considered include rotations and vibrations of molecules (vibron model), collective modes in nuclei (interacting boson model), the atomic shell model, the nuclear shell model, and the quark model of hadrons. One of the key concepts in the application of Lie algebraic methods in physics, that of spectrum generating algebras and their associated dynamic symmetries, is also discussed. The book highlights a number of examples that help to illustrate the abstract algebraic definitions and includes a summary of many formulas of practical interest, such as the eigenvalues of Casimir operators...

  12. On the Use of Computer Algebra Systems and Enclosure Methods in the Modelling and Optimization of Biotechnological Processes

    OpenAIRE

    Svetoslav Markov

    2005-01-01

    This survey paper aims to promote certain novel mathematical tools, such as computer algebra systems, enclosure methods and interval analysis, to the mathematical modelling and optimization of biotechnological processes.

  13. Vibrational spectrum of CF4 isotopes in an algebraic model

    Indian Academy of Sciences (India)

    Joydeep Choudhury; Srinivasa Rao Karumuri; Nirmal Kumar Sarkar; Ramendu Bhattacharjee

    2009-11-01

    n this paper the stretching vibrational modes of CF4 isotopes are calculated up to first overtone using the one-dimensional vibron model for the first time. The model Hamiltonian so constructed seems to describe the C–F stretching modes accurately using a relatively small set of well-defined parameters.

  14. Meadow enriched ACP process algebras

    OpenAIRE

    J.A. Bergstra; Middelburg, C.A.

    2009-01-01

    We introduce the notion of an ACP process algebra. The models of the axiom system ACP are the origin of this notion. ACP process algebras have to do with processes in which no data are involved. We also introduce the notion of a meadow enriched ACP process algebra, which is a simple generalization of the notion of an ACP process algebra to processes in which data are involved. In meadow enriched ACP process algebras, the mathematical structure for data is a meadow.

  15. Bus Network Modeling Using Ant Algorithms

    Directory of Open Access Journals (Sweden)

    Sepideh Eshragh

    2010-02-01

    Full Text Available Bus transit network modeling is a complex and combinatorial problem. The main purpose of this paper is to apply a contemporary method for designing a bus transit network with the objective of achieving optimum results. The method is called Ant Algorithms, a Meta Heuristic method, which has been applied to optimization problems in transportation with noticeable success. The description of the algorithm, as well as the main methodology and computations, is presented in this paper. Furthermore, a case study using Ant Algorithms applied to the city of Ghazvin, one of the most important suburbs of Tehran, Iran, is presented.

  16. Adaptive Genetic Algorithm Model for Intrusion Detection

    Directory of Open Access Journals (Sweden)

    K. S. Anil Kumar

    2012-09-01

    Full Text Available Intrusion detection systems are intelligent systems designed to identify and prevent the misuse of computer networks and systems. Various approaches to Intrusion Detection are currently being used, but they are relatively ineffective. Thus the emerging network security systems need be part of the life system and this ispossible only by embedding knowledge into the network. The Adaptive Genetic Algorithm Model - IDS comprising of K-Means clustering Algorithm, Genetic Algorithm and Neural Network techniques. Thetechnique is tested using multitude of background knowledge sets in DARPA network traffic datasets.

  17. A deformation of quantum affine algebra in squashed Wess-Zumino-Novikov-Witten models

    International Nuclear Information System (INIS)

    We proceed to study infinite-dimensional symmetries in two-dimensional squashed Wess-Zumino-Novikov-Witten models at the classical level. The target space is given by squashed S3 and the isometry is SU(2)L × U(1)R. It is known that SU(2)L is enhanced to a couple of Yangians. We reveal here that an infinite-dimensional extension of U(1)R is a deformation of quantum affine algebra, where a new deformation parameter is provided with the coefficient of the Wess-Zumino term. Then we consider the relation between the deformed quantum affine algebra and the pair of Yangians from the viewpoint of the left-right duality of monodromy matrices. The integrable structure is also discussed by computing the r/s-matrices that satisfy the extended classical Yang-Baxter equation. Finally, two degenerate limits are discussed

  18. From Clifford Algebra of Nonrelativistic Phase Space to Quarks and Leptons of the Standard Model

    CERN Document Server

    Żenczykowski, Piotr

    2015-01-01

    We review a recently proposed Clifford-algebra approach to elementary particles. We start with: (1) a philosophical background that motivates a maximally symmetric treatment of position and momentum variables, and: (2) an analysis of the minimal conceptual assumptions needed in quark mass extraction procedures. With these points in mind, a variation on Born's reciprocity argument provides us with an unorthodox view on the problem of mass. The idea of space quantization suggests then the linearization of the nonrelativistic quadratic form ${\\bf p}^2 +{\\bf x}^2$ with position and momentum satisfying standard commutation relations. This leads to the 64-dimensional Clifford algebra ${Cl}_{6,0}$ of nonrelativistic phase space within which one identifies the internal quantum numbers of a single Standard Model generation of elementary particles (i.e. weak isospin, hypercharge, and color). The relevant quantum numbers are naturally linked to the symmetries of macroscopic phase space. It is shown that the obtained pha...

  19. Conformal Field Theory, Vertex Operator Algebra and Stochastic Loewner Evolution in Ising Model

    CERN Document Server

    Zahabi, Ali

    2015-01-01

    We review the algebraic and analytic aspects of the conformal field theory (CFT) and its relation to the stochastic Loewner evolution (SLE) in an example of the Ising model. We obtain the scaling limit of the correlation functions of Ising free fermions on an arbitrary simply connected two-dimensional domain $D$. Then, we study the analytic and algebraic aspects of the fermionic CFT on $D$, using the Fock space formalism of fields, and the Clifford vertex operator algebra (VOA). These constructions lead to the conformal field theory of the Fock space fields and the fermionic Fock space of states and their relations in case of the Ising free fermions. Furthermore, we investigate the conformal structure of the fermionic Fock space fields and the Clifford VOA, namely the operator product expansions, correlation functions and differential equations. Finally, by using the Clifford VOA and the fermionic CFT, we investigate a rigorous realization of the CFT/SLE correspondence in the Ising model. First, by studying t...

  20. A new algebraic structure in the standard model of particle physics

    CERN Document Server

    Boyle, Latham

    2016-01-01

    We introduce a new formulation of non-commutative geometry (NCG): we explain its mathematical advantages and its success in capturing the structure of the standard model of particle physics. The idea, in brief, is to represent $A$ (the algebra of differential forms on some possibly-noncommutative space) on $H$ (the Hilbert space of spinors on that space); and to reinterpret this representation as a simple super-algebra $B=A\\oplus H$ with even part $A$ and odd part $H$. $B$ is the fundamental object in our approach: we show that (nearly) all of the basic axioms and assumptions of the traditional ("spectral triple") formulation of NCG are elegantly recovered from the simple requirement that $B$ should be a differential graded $\\ast$-algebra (or "$\\ast$-DGA"). But this requirement also yields other, new, geometrical constraints. When we apply our formalism to the NCG traditionally used to describe the standard model of particle physics, we find that these new constraints are physically meaningful and phenomenolo...

  1. Analysis of DIRAC's behavior using model checking with process algebra

    CERN Document Server

    Remenska, Daniela; Willemse, Tim; Bal, Henri; Verstoep, Kees; Fokkink, Wan; Charpentier, Philippe; Diaz, Ricardo Graciani; Lanciotti, Elisa; Roiser, Stefan; Ciba, Krzysztof

    2012-01-01

    DIRAC is the grid solution developed to support LHCb production activities as well as user data analysis. It consists of distributed services and agents delivering the workload to the grid resources. Services maintain database back-ends to store dynamic state information of entities such as jobs, queues, staging requests, etc. Agents use polling to check and possibly react to changes in the system state. Each agent's logic is relatively simple, the main complexity lies in their cooperation. Agents run concurrently, and collaborate using the databases as shared memory. The databases can be accessed directly by the agents if running locally or through a DIRAC service interface if necessary. This shared-memory model causes entities to occasionally get into inconsistent states. Tracing and fixing such problems becomes formidable due to the inherent parallelism present. We propose more rigorous methods to cope with this. Model checking is one such technique for analysis of an abstract model of a system. Unlike con...

  2. Enlarged symmetry algebras of spin chains, loop models, and S-matrices

    International Nuclear Information System (INIS)

    The symmetry algebras of certain families of quantum spin chains are considered in detail. The simplest examples possess m states per site (m>=2), with nearest-neighbor interactions with U(m) symmetry, under which the sites transform alternately along the chain in the fundamental m and its conjugate representation m-bar. We find that these spin chains, even with arbitrary coefficients of these interactions, have a symmetry algebra Am much larger than U(m), which implies that the energy eigenstates fall into sectors that for open chains (i.e., free boundary conditions) can be labeled by j=0,1,...,L, for the 2L-site chain such that the degeneracies of all eigenvalues in the jth sector are generically the same and increase rapidly with j. For large j, these degeneracies are much larger than those that would be expected from the U(m) symmetry alone. The enlarged symmetry algebra Am(2L) consists of operators that commute in this space of states with the Temperley-Lieb algebra that is generated by the set of nearest-neighbor interaction terms; Am(2L) is not a Yangian. There are similar results for supersymmetric chains with gl(m+n|n) symmetry of nearest-neighbor interactions, and a richer representation structure for closed chains (i.e., periodic boundary conditions). The symmetries also apply to the loop models that can be obtained from the spin chains in a spacetime or transfer matrix picture. In the loop language, the symmetries arise because the loops cannot cross. We further define tensor products of representations (for the open chains) by joining chains end to end. The fusion rules for decomposing the tensor product of representations labeled j1 and j2 take the same form as the Clebsch-Gordan series for SU(2). This and other structures turn the symmetry algebra Am into a ribbon Hopf algebra, and we show that this is 'Morita equivalent' to the quantum group Uq(sl2) for m=q+q-1. The open-chain results are extended to the cases vertical bar m vertical barm or Uq(sl2

  3. Bus Network Modeling Using Ant Algorithms

    OpenAIRE

    Sepideh Eshragh; Shahriar Afandizadeh Zargari; Ardeshir Faghri; Earl Rusty Lee

    2010-01-01

    Bus transit network modeling is a complex and combinatorial problem. The main purpose of this paper is to apply a contemporary method for designing a bus transit network with the objective of achieving optimum results. The method is called Ant Algorithms, a Meta Heuristic method, which has been applied to optimization problems in transportation with noticeable success. The description of the algorithm, as well as the main methodology and computations, is presented in this paper. Furthermore, ...

  4. Max plus at work modeling and analysis of synchronized systems a course on max-plus algebra and its applications

    CERN Document Server

    Heidergott, Bernd; van der Woude, Jacob

    2014-01-01

    Trains pull into a railroad station and must wait for each other before leaving again in order to let passengers change trains. How do mathematicians then calculate a railroad timetable that accurately reflects their comings and goings? One approach is to use max-plus algebra, a framework used to model Discrete Event Systems, which are well suited to describe the ordering and timing of events. This is the first textbook on max-plus algebra, providing a concise and self-contained introduction to the topic. Applications of max-plus algebra abound in the world around us. Traffic systems, compu

  5. Teaching Algebra and Geometry Concepts by Modeling Telescope Optics

    Science.gov (United States)

    Siegel, Lauren M.; Dickinson, Gail; Hooper, Eric J.; Daniels, Mark

    2008-01-01

    This article describes preparation and delivery of high school mathematics lessons that integrate mathematics and astronomy through The Geometer's Sketchpad models, traditional proof, and inquiry-based activities. The lessons were created by a University of Texas UTeach preservice teacher as part of a project-based field experience in which high…

  6. Moments, Model Reduction and Nonlinearity in Solving linear Algebraic Problems

    Czech Academy of Sciences Publication Activity Database

    Strakoš, Z.; Hnětynková, I.; O'Leary, D.P.; Plešinger, M.; Tichý, Petr

    Prague : ICS AS CR, 2012. [Joint French-Czech Workshop on Krylov Methods for Inverse Problem s. 19.07.2012-20.07.2012, Prague] Institutional support: RVO:67985807 Keywords : problem of moments * model reduction * Krylov subspace Subject RIV: BA - General Mathematics

  7. Algebraic nonlinear collective motion

    OpenAIRE

    Troupe, J.; Rosensteel, G.

    1999-01-01

    Finite-dimensional Lie algebras of vector fields determine geometrical collective models in quantum and classical physics. Every set of vector fields on Euclidean space that generates the Lie algebra sl(3, R) and contains the angular momentum algebra so(3) is determined. The subset of divergence-free sl(3, R) vector fields is proven to be indexed by a real number $\\Lambda$. The $\\Lambda=0$ solution is the linear representation that corresponds to the Riemann ellipsoidal model. The nonlinear g...

  8. Lighthouse: A User-Centered Web Service for Linear Algebra Software

    OpenAIRE

    Norris, Boyana; Bernstein, Sa-Lin; Nair, Ramya; Jessup, Elizabeth

    2014-01-01

    Various fields of science and engineering rely on linear algebra for large scale data analysis, modeling and simulation, machine learning, and other applied problems. Linear algebra computations often dominate the execution time of such applications. Meanwhile, experts in these domains typically lack the training or time required to develop efficient, high-performance implementations of linear algebra algorithms. In the Lighthouse project, we enable developers with varied backgrounds to readi...

  9. Model Checking Algorithms for CTMDPs

    DEFF Research Database (Denmark)

    Buchholz, Peter; Hahn, Ernst Moritz; Hermanns, Holger;

    2011-01-01

    Continuous Stochastic Logic (CSL) can be interpreted over continuoustime Markov decision processes (CTMDPs) to specify quantitative properties of stochastic systems that allow some external control. Model checking CSL formulae over CTMDPs requires then the computation of optimal control strategie...

  10. Graphical model construction based on evolutionary algorithms

    Institute of Scientific and Technical Information of China (English)

    Youlong YANG; Yan WU; Sanyang LIU

    2006-01-01

    Using Bayesian networks to model promising solutions from the current population of the evolutionary algorithms can ensure efficiency and intelligence search for the optimum. However, to construct a Bayesian network that fits a given dataset is a NP-hard problem, and it also needs consuming mass computational resources. This paper develops a methodology for constructing a graphical model based on Bayesian Dirichlet metric. Our approach is derived from a set of propositions and theorems by researching the local metric relationship of networks matching dataset. This paper presents the algorithm to construct a tree model from a set of potential solutions using above approach. This method is important not only for evolutionary algorithms based on graphical models, but also for machine learning and data mining.The experimental results show that the exact theoretical results and the approximations match very well.

  11. Algebraic statistics computational commutative algebra in statistics

    CERN Document Server

    Pistone, Giovanni; Wynn, Henry P

    2000-01-01

    Written by pioneers in this exciting new field, Algebraic Statistics introduces the application of polynomial algebra to experimental design, discrete probability, and statistics. It begins with an introduction to Gröbner bases and a thorough description of their applications to experimental design. A special chapter covers the binary case with new application to coherent systems in reliability and two level factorial designs. The work paves the way, in the last two chapters, for the application of computer algebra to discrete probability and statistical modelling through the important concept of an algebraic statistical model.As the first book on the subject, Algebraic Statistics presents many opportunities for spin-off research and applications and should become a landmark work welcomed by both the statistical community and its relatives in mathematics and computer science.

  12. A branch-and-bound methodology within algebraic modelling systems

    OpenAIRE

    Bisschop, J.J.; Heerink, J.B.J.; Kloosterman, G.

    1998-01-01

    Through the use of application-specific branch-and-bound directives it is possible to find solutions to combinatorial models that would otherwise be difficult or impossible to find by just using generic branch-and-bound techniques within the framework of mathematical programming. {\\sc Minto} is an example of a system which offers the possibility to incorporate user-provided directives (written in {\\sc C}) to guide the branch-and-bound search. Its main focus, however, remains on mathematical p...

  13. The standard model of quantum physics in Clifford algebra

    CERN Document Server

    Daviau, Claude

    2016-01-01

    We extend to gravitation our previous study of a quantum wave for all particles and antiparticles of each generation (electron + neutrino + u and d quarks for instance). This wave equation is form invariant under Cl3*, then relativistic invariant. It is gauge invariant under the gauge group of the standard model, with a mass term: this was impossible before, and the consequence was an impossibility to link gauge interactions and gravitation.

  14. A Clifford algebra associated to generalized Fibonacci quaternions

    OpenAIRE

    Flaut, Cristina

    2014-01-01

    In this paper we find a Clifford algebra associated to generalized Fibonacci quaternions. In this way, we provide a nice algorithm to obtain a division quaternion algebra starting from a quaternion non-division algebra and vice-versa.

  15. Safety properties test data selection from an algebraic model of Lustre programs

    International Nuclear Information System (INIS)

    In the context to validate an industrial software, which is a set of reactive programs, we are confronted with the safety properties verification problem. This thesis reports an experience in which our goal is to generate the test data satisfying a safety property. The software to be validated is designed with the SAGA tool, in which a view can be regarded as a program of a programming language called LUSTRE. We adapt a test data generation tool called LOFT to this kind of programs. In this way, we consider the functional testing method on which the LOFT tool is based. Given any LUSTRE program, we try to give it an algebraic model because LOFT treats algebraic specifications. So, our task consists In defining a formal framework in which any LUSTRE program can be translated into a LOFT module: based on an operational semantics of the LUSTRE language, the flow types 'T-flow' are specified with the constructive algebraic formalism, then implemented in a LOFT modules base. Next, in a test selection process assisted by LOFT, a safety property Is expressed by an equation to join other control hypotheses, and to guide the test data selection. Some concrete test data set are generated in this way on some significant examples. This experience confirm the feasibility of formal method on test data selection for the reactive programs. (author)

  16. Jaynes-Cummings model and the deformed-oscillator algebra

    International Nuclear Information System (INIS)

    We study the time evolution of the deformed Jaynes-Cummings model (DJCM). It is shown that the standard JCM and its recent non-linear generalizations involving the intensity-dependent coupling and/or the multiphoton coupling are only particular cases of the DJCM. The time evolution of the mean phonon number and the population inversion are evaluated. A special case of the q-deformed JCM is analyzed explicitly. The long time quasi-periodic revival effects of the q-deformed JCM are observed for q∼1 and an initially large mean photon number. For other values of the deformation parameter q we observe chaotic-like behaviour of the population inversion. Photons are assumed to be initially in the deformed coherent state. ((orig.))

  17. Monomial algebras

    CERN Document Server

    Villarreal, Rafael

    2015-01-01

    The book stresses the interplay between several areas of pure and applied mathematics, emphasizing the central role of monomial algebras. It unifies the classical results of commutative algebra with central results and notions from graph theory, combinatorics, linear algebra, integer programming, and combinatorial optimization. The book introduces various methods to study monomial algebras and their presentation ideals, including Stanley-Reisner rings, subrings and blowup algebra-emphasizing square free quadratics, hypergraph clutters, and effective computational methods.

  18. Algebraic equations for the exceptional eigenspectrum of the generalized Rabi model

    International Nuclear Information System (INIS)

    We obtain the exceptional part of the eigenspectrum of the generalized Rabi model, also known as the driven Rabi model, in terms of the roots of a set of algebraic equations. This approach provides a product form for the wavefunction components and allows an explicit connection with recent results obtained for the wavefunction in terms of truncated confluent Heun functions. Other approaches are also compared. For particular parameter values the exceptional part of the eigenspectrum consists of doubly degenerate crossing points. We give a proof for the number of roots of the constraint polynomials and discuss the number of crossing points. (paper)

  19. From the topological development of matrix models to the topological string theory: arrangement of surfaces through algebraic geometry

    International Nuclear Information System (INIS)

    The 2-matrix model has been introduced to study Ising model on random surfaces. Since then, the link between matrix models and arrangement of discrete surfaces has strongly tightened. This manuscript aims to investigate these deep links and extend them beyond the matrix models, following my work's evolution. First, I take care to define properly the hermitian 2 matrix model which gives rise to generating functions of discrete surfaces equipped with a spin structure. Then, I show how to compute all the terms in the topological expansion of any observable by using algebraic geometry tools. They are obtained as differential forms on an algebraic curve associated to the model: the spectral curve. In a second part, I show how to define such differentials on any algebraic curve even if it does not come from a matrix model. I then study their numerous symmetry properties under deformations of the algebraic curve. In particular, I show that these objects coincide with the topological expansion of the observable of a matrix model if the algebraic curve is the spectral curve of this model. Finally, I show that the fine tuning of the parameters ensures that these objects can be promoted to modular invariants and satisfy the holomorphic anomaly equation of the Kodaira-Spencer theory. This gives a new hint that the Dijkgraaf-Vafa conjecture is correct. (author)

  20. Genetic Algorithms for a Parameter Estimation of a Fermentation Process Model: A Comparison

    Directory of Open Access Journals (Sweden)

    Olympia Roeva

    2005-12-01

    Full Text Available In this paper the problem of a parameter estimation using genetic algorithms is examined. A case study considering the estimation of 6 parameters of a nonlinear dynamic model of E. coli fermentation is presented as a test problem. The parameter estimation problem is stated as a nonlinear programming problem subject to nonlinear differential-algebraic constraints. This problem is known to be frequently ill-conditioned and multimodal. Thus, traditional (gradient-based local optimization methods fail to arrive satisfied solutions. To overcome their limitations, the use of different genetic algorithms as stochastic global optimization methods is explored. These algorithms are proved to be very suitable for the optimization of highly non-linear problems with many variables. Genetic algorithms can guarantee global optimality and robustness. These facts make them advantageous in use for parameter identification of fermentation models. A comparison between simple, modified and multi-population genetic algorithms is presented. The best result is obtained using the modified genetic algorithm. The considered algorithms converged very closely to the cost value but the modified algorithm is in times faster than other two.

  1. THE ALGEBRAIC METHOD OF RATIONAL INTERPOLATION

    Institute of Scientific and Technical Information of China (English)

    Cai Shoufeng; Zhang Shugong

    2005-01-01

    This paper deals with rational interpolation. From algebraic viewpoint, we present an algebraic formulation of rational interpolation and discuss the existence of the interpolation function. Finally an algorithm for univariate case and an example are presented.

  2. Enlarged symmetry algebras of spin chains, loop models, and S-matrices

    Energy Technology Data Exchange (ETDEWEB)

    Read, N. [Department of Physics, Yale University, PO Box 208120, New Haven, CT 06520-8120 (United States)]. E-mail: nicholas.read@yale.edu; Saleur, H. [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France) and Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089 (United States)]. E-mail: hubert.saleur@cea.fr

    2007-08-20

    The symmetry algebras of certain families of quantum spin chains are considered in detail. The simplest examples possess m states per site (m>=2), with nearest-neighbor interactions with U(m) symmetry, under which the sites transform alternately along the chain in the fundamental m and its conjugate representation m-bar. We find that these spin chains, even with arbitrary coefficients of these interactions, have a symmetry algebra A{sub m} much larger than U(m), which implies that the energy eigenstates fall into sectors that for open chains (i.e., free boundary conditions) can be labeled by j=0,1,...,L, for the 2L-site chain such that the degeneracies of all eigenvalues in the jth sector are generically the same and increase rapidly with j. For large j, these degeneracies are much larger than those that would be expected from the U(m) symmetry alone. The enlarged symmetry algebra A{sub m}(2L) consists of operators that commute in this space of states with the Temperley-Lieb algebra that is generated by the set of nearest-neighbor interaction terms; A{sub m}(2L) is not a Yangian. There are similar results for supersymmetric chains with gl(m+n|n) symmetry of nearest-neighbor interactions, and a richer representation structure for closed chains (i.e., periodic boundary conditions). The symmetries also apply to the loop models that can be obtained from the spin chains in a spacetime or transfer matrix picture. In the loop language, the symmetries arise because the loops cannot cross. We further define tensor products of representations (for the open chains) by joining chains end to end. The fusion rules for decomposing the tensor product of representations labeled j{sub 1} and j{sub 2} take the same form as the Clebsch-Gordan series for SU(2). This and other structures turn the symmetry algebra A{sub m} into a ribbon Hopf algebra, and we show that this is 'Morita equivalent' to the quantum group U{sub q}(sl{sub 2}) for m=q+q{sup -1}. The open-chain results

  3. New explicit algebraic stress and flux model for active scalar and simulation of shear stratified cylinder wake flow

    Institute of Scientific and Technical Information of China (English)

    HUA ZuLin; GU Li; XING LingHang; DAI WenHong

    2009-01-01

    On the numerical simulation of active scalar, a new explicit algebraic expression on active scalar flux was derived based on Wikstrom, Wallin and Johansson model (aWWJ model). Reynolds stress algebraic expressions were added by a term to account for the buoyancy effect. The new explicit Reynolds stress and active scalar flux model was then established. Governing equations of this model were solved by finite volume method with unstructured grids. The thermal shear stratified cylinder wake flow was computed by this new model. The computational results are in good agreement with Laboratorial measurements. This work is the development on modeling of explicit algebraic Reynolds stress and scalar flux, and is also a further modification of the aWWJ model for complex situations such as a shear stratified flow.

  4. A Feedback Control in Max-Algebra

    OpenAIRE

    Menguy, Eric; Boimond, Jean-Louis; Hardouin, Laurent

    1997-01-01

    International audience For timed event graphs, linear models were obtained using Max-Algebra. This paper presents a method to control such systems. After describing the optimal solution of a model tracking problem, we propose a feedback control structure in order to take into account a possible modeling error. We present its construction, its main properties and an algorithm for its practical implementation. An illustrative example is provided.

  5. Basic notions of algebra

    CERN Document Server

    Shafarevich, Igor Rostislavovich

    2005-01-01

    This book is wholeheartedly recommended to every student or user of mathematics. Although the author modestly describes his book as 'merely an attempt to talk about' algebra, he succeeds in writing an extremely original and highly informative essay on algebra and its place in modern mathematics and science. From the fields, commutative rings and groups studied in every university math course, through Lie groups and algebras to cohomology and category theory, the author shows how the origins of each algebraic concept can be related to attempts to model phenomena in physics or in other branches

  6. Phantom energy from graded algebras

    OpenAIRE

    Chaves, Max; Singleton, Douglas

    2006-01-01

    We construct a model of phantom energy using the graded Lie algebra SU(2/1). The negative kinetic energy of the phantom field emerges naturally from the graded Lie algebra, resulting in an equation of state with w

  7. Algebraic Bethe ansatz for the six vertex model with upper triangular K-matrices

    International Nuclear Information System (INIS)

    We consider a formulation of the algebraic Bethe ansatz for the six vertex model with non-diagonal open boundaries. Specifically, we study the case where both left and right K-matrices have an upper triangular form. We show that the main difficulty entailed by those forms of the K-matrices is the construction of the excited states. However, it is possible to treat this problem with the aid of an auxiliary transfer matrix and by means of a generalized creation operator. (paper)

  8. Thermodiffusion in Multicomponent Mixtures Thermodynamic, Algebraic, and Neuro-Computing Models

    CERN Document Server

    Srinivasan, Seshasai

    2013-01-01

    Thermodiffusion in Multicomponent Mixtures presents the computational approaches that are employed in the study of thermodiffusion in various types of mixtures, namely, hydrocarbons, polymers, water-alcohol, molten metals, and so forth. We present a detailed formalism of these methods that are based on non-equilibrium thermodynamics or algebraic correlations or principles of the artificial neural network. The book will serve as single complete reference to understand the theoretical derivations of thermodiffusion models and its application to different types of multi-component mixtures. An exhaustive discussion of these is used to give a complete perspective of the principles and the key factors that govern the thermodiffusion process.

  9. RSOS models and Jantzen-Seitz representations of Hecke algebras at roots of unity

    CERN Document Server

    Foda, O E; Okado, M; Thibon, J Y; Welsh, Trevor A; Foda, Omar; Leclerc, Bernard; Okado, Masato; Thibon, Jean-Yves; Welsh, Trevor A.

    1997-01-01

    A special family of partitions occurs in two apparently unrelated contexts: the evaluation of 1-dimensional configuration sums of certain RSOS models, and the modular representation theory of symmetric groups or their Hecke algebras $H_m$. We provide an explanation of this coincidence by showing how the irreducible $H_m$-modules which remain irreducible under restriction to $H_{m-1}$ (Jantzen-Seitz modules) can be determined from the decomposition of a tensor product of representations of affine $\\sl_n$.

  10. Modeling boyciana-fish-human interaction with partial differential algebraic equations.

    Science.gov (United States)

    Jiang, Yushan; Zhang, Qingling; Wang, Haiyan

    2016-07-01

    Under the influence of human population distribution, the boyciana-fish ecological system is considered. First, the system can be described as a nonlinear partial differential algebraic equations system (PDAEs) with Neumann boundary conditions and ratio-dependent functional response. Second, we examine the system's persistence properties: the loacl stabilities of positive steady states, the absorbtion region and the global stability. And the proposed approach is illustrated by numerical simulation. Finally, by using the realistic data collected in the past fourteen years, the PDAEs parameter optimization model is built to predict the boyciana population. PMID:27155570

  11. Algebraic Bethe ansatz for the XXX chain with triangular boundaries and Gaudin model

    Science.gov (United States)

    Cirilo António, N.; Manojlović, N.; Salom, I.

    2014-12-01

    We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model.

  12. Algebraic Bethe ansatz for the XXX chain with triangular boundaries and Gaudin model

    Energy Technology Data Exchange (ETDEWEB)

    Cirilo António, N., E-mail: nantonio@math.ist.utl.pt [Centro de Análise Funcional e Aplicações, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Manojlović, N., E-mail: nmanoj@ualg.pt [Grupo de Física Matemática da Universidade de Lisboa, Av. Prof. Gama Pinto 2, PT-1649-003 Lisboa (Portugal); Departamento de Matemática, F.C.T., Universidade do Algarve, Campus de Gambelas, PT-8005-139 Faro (Portugal); Salom, I., E-mail: isalom@ipb.ac.rs [Institute of Physics, University of Belgrade, P.O. Box 57, 11080 Belgrade (Serbia)

    2014-12-15

    We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model.

  13. Algebraic Bethe ansatz for the XXX chain with triangular boundaries and Gaudin model

    International Nuclear Information System (INIS)

    We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model

  14. Weekly Fleet Assignment Model and Algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHU Xing-hui; ZHU Jin-fu; GONG Zai-wu

    2007-01-01

    A 0-1 integer programming model for weekly fleet assignment was put forward based on linear network and weekly flight scheduling in China. In this model, the objective function is to maximize the total profit of fleet assignment, subject to the constraints of coverage, aircraft flow balance, fleet size, aircraft availability, aircraft usage, flight restriction, aircraft seat capacity,and stopover. Then the branch-and-bound algorithm based on special ordered set was applied to solve the model. At last, a realworld case study on an airline with 5 fleets, 48 aircrafts and 1 786 flight legs indicated that the profit increase was $1591276 one week and the running time was no more than 4 min, which shows that the model and algorithm are fairly good for domestic airline.

  15. Models and Algorithms for Crowdsourcing Discovery

    OpenAIRE

    Faridani, Siamak

    2012-01-01

    The internet enables us to collect and store unprecedented amounts of data. We need better models for processing, analyzing, and making conclusions from the data. In this work, crowdsourcing is presented as a viable option for collecting data, extracting patterns and insights from big data. Humans in collaboration, when provided with appropriate tools, can collectively see patterns, extract insights and draw conclusions from data. We study different models and algorithms for crowdsourcing dis...

  16. Stream Processing Algorithms that model behavior changes

    OpenAIRE

    Capponi, Agostino; Chandy, Mani

    2005-01-01

    This paper presents algorithms that fuse information in multiple event streams to update models that represent system behavior. System behaviors vary over time; for example, an information network varies from heavily loaded to lightly loaded conditions; patterns of incidence of disease change at the onset of pandemics; file access patterns change from proper usage to improper use that may signify insider threat. The models that represent behavior must be updated frequently to adapt to chan...

  17. Nonnegative Matrix Factorization: Model, Algorithms and Applications

    OpenAIRE

    Zhang, Xiang-Sun; Zhang, Zhong-Yuan

    2013-01-01

    Nonnegative Matrix Factorization (NMF) is becoming one of the most popular models in data mining society recently. NMF can extract hidden patterns from a series of high-dimensional vectors automatically, and has been applied for dimensional reduction, unsupervised learning (image processing, clustering and co-clustering, etc.) and prediction successfully. This paper surveys NMF in terms of the research history, model formulation, algorithms and applications. In summary, NMF has good interpret...

  18. Efficient Algorithms for Parsing the DOP Model

    CERN Document Server

    Goodman, J

    1996-01-01

    Excellent results have been reported for Data-Oriented Parsing (DOP) of natural language texts (Bod, 1993). Unfortunately, existing algorithms are both computationally intensive and difficult to implement. Previous algorithms are expensive due to two factors: the exponential number of rules that must be generated and the use of a Monte Carlo parsing algorithm. In this paper we solve the first problem by a novel reduction of the DOP model to a small, equivalent probabilistic context-free grammar. We solve the second problem by a novel deterministic parsing strategy that maximizes the expected number of correct constituents, rather than the probability of a correct parse tree. Using the optimizations, experiments yield a 97% crossing brackets rate and 88% zero crossing brackets rate. This differs significantly from the results reported by Bod, and is comparable to results from a duplication of Pereira and Schabes's (1992) experiment on the same data. We show that Bod's results are at least partially due to an e...

  19. Hidden Q-structure and Lie 3-algebra for non-abelian superconformal models in six dimensions

    CERN Document Server

    Lavau, Sylvain; Strobl, Thomas

    2014-01-01

    We disclose the mathematical structure underlying the gauge field sector of the recently constructed non-abelian superconformal models in six spacetime dimensions. This is a coupled system of 1-form, 2-form, and 3-form gauge fields. We show that the algebraic consistency constraints governing this system permit to define a Lie 3-algebra, generalizing the structural Lie algebra of a standard Yang-Mills theory to the setting of a higher bundle. Reformulating the Lie 3-algebra in terms of a nilpotent degree 1 BRST-type operator Q, this higher bundle can be compactly described by means of a Q-bundle; its fiber is the shifted tangent of the Q-manifold corresponding to the Lie 3-algebra and its base the odd tangent bundle of spacetime equipped with the de Rham differential. The generalized Bianchi identities can then be retrieved concisely from Q^2=0, which encode all the essence of the structural identities. Gauge transformations are identified as vertical inner automorphisms of such a bundle, their algebra being ...

  20. The quantum Rabi model and Lie algebra representations of sl2

    International Nuclear Information System (INIS)

    The aim of the present paper is to understand the spectral problem of the quantum Rabi model in terms of Lie algebra representations of sl2(R). We define a second order element of the universal enveloping algebra U(sl2) of sl2(R), which, through the image of a principal series representation of sl2(R), provides a picture equivalent to the quantum Rabi model drawn by confluent Heun differential equations. By this description, in particular, we give a representation theoretic interpretation of the degenerate part of the spectrum (i.e., Judd's eigenstates) of the Rabi Hamiltonian due to Kuś in 1985, which is a part of the exceptional spectrum parameterized by integers. We also discuss the non-degenerate part of the exceptional spectrum of the model, in addition to the Judd eigenstates, from a viewpoint of infinite dimensional irreducible submodules (or subquotients) of the non-unitary principal series such as holomorphic discrete series representations of sl2(R). (paper)

  1. An evolutionary algorithm for model selection

    International Nuclear Information System (INIS)

    When performing partial-wave analyses of multi-body final states, the choice of the fit model, i.e. the set of waves to be used in the fit, can significantly alter the results of the partial wave fit. Traditionally, the models were chosen based on physical arguments and by observing the changes in log-likelihood of the fits. To reduce possible bias in the model selection process, an evolutionary algorithm was developed based on a Bayesian goodness-of-fit criterion which takes into account the model complexity. Starting from systematically constructed pools of waves which contain significantly more waves than the typical fit model, the algorithm yields a model with an optimal log-likelihood and with a number of partial waves which is appropriate for the number of events in the data. Partial waves with small contributions to the total intensity are penalized and likely to be dropped during the selection process, as are models were excessive correlations between single waves occur. Due to the automated nature of the model selection, a much larger part of the model space can be explored than would be possible in a manual selection. In addition the method allows to assess the dependence of the fit result on the fit model which is an important contribution to the systematic uncertainty.

  2. Entanglement in a model for Hawking radiation: An Application of Quadratic Algebras

    CERN Document Server

    Bambah, Bindu A; Shreecharan, T; Prasad, K Siva

    2012-01-01

    Quadratic polynomially deformed $su(1,1)$ and $su(2)$ algebras are utilised in model Hamiltonians to show how the gravitational system consisting of a black hole, infalling radiation and outgoing (Hawking) radiation can be solved exactly. The models allow us to study the long-time behaviour of the black hole and its outgoing modes. In particular, we calculate the bipartite entanglement entropies of subsystems consisting of a) infalling plus outgoing modes and b) black hole modes plus the infalling modes,using the Janus-faced nature of the model.The long-time behaviour also gives us glimpses of modifications in the character of Hawking radiation. Lastly, we study the phenomenon of superradiance in our model in analogy with atomic Dicke superradiance.

  3. Supertropical algebra

    OpenAIRE

    Izhakian, Zur; Rowen, Louis

    2008-01-01

    We develop the algebraic polynomial theory for "supertropical algebra," as initiated earlier over the real numbers by the first author. The main innovation there was the introduction of "ghost elements," which also play the key role in our structure theory. Here, we work somewhat more generally over an ordered monoid, and develop a theory which contains the analogs of several basic theorems of classical commutative algebra. This structure enables one to develop a Zariski-type algebraic geomet...

  4. Lorentz invariant noncommutative algebra for cosmological models coupled to a perfect fluid

    International Nuclear Information System (INIS)

    Full text: In current theoretical physics there is a relevant number of theoretical investigations that lead to believe that at the first moments of our Universe, the geometry was not commutative and the dominating physics at that time was ruled by the laws of noncommutative (NC) geometry. Therefore, the idea is that the physics of the early moments can be constructed based on these concepts. The first published work using the idea of a NC spacetime were carried out by Snyder who believed that NC principles could make the quantum field theory infinities disappear. However, it did not occur and Snyder's ideas were put to sleep for a long time. The main modern motivations that rekindle the investigation about NC field theories came from string theory and quantum gravity. In the context of quantum mechanics for example, R. Banerjee discussed how NC structures appear in planar quantum mechanics providing a useful way for obtaining them. The analysis was based on the NC algebra used in planar quantum mechanics that was originated from 't Hooft's analysis on dissipation and quantization. In this work we carry out a NC algebra analysis of the Friedmann-Robert-Walker model, coupled to a perfect fluid and in the presence of a cosmological constant. The classical field equations are modified, by the introduction of a shift operator, in order to introduce noncommutativity in these models. (author)

  5. Lorentz invariant noncommutative algebra for cosmological models coupled to a perfect fluid

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Everton M.C.; Marcial, Mateus V.; Mendes, Albert C.R.; Oliveira, Wilson [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil); Universidade Federal de Juiz de Fora, MG (Brazil)

    2013-07-01

    Full text: In current theoretical physics there is a relevant number of theoretical investigations that lead to believe that at the first moments of our Universe, the geometry was not commutative and the dominating physics at that time was ruled by the laws of noncommutative (NC) geometry. Therefore, the idea is that the physics of the early moments can be constructed based on these concepts. The first published work using the idea of a NC spacetime were carried out by Snyder who believed that NC principles could make the quantum field theory infinities disappear. However, it did not occur and Snyder's ideas were put to sleep for a long time. The main modern motivations that rekindle the investigation about NC field theories came from string theory and quantum gravity. In the context of quantum mechanics for example, R. Banerjee discussed how NC structures appear in planar quantum mechanics providing a useful way for obtaining them. The analysis was based on the NC algebra used in planar quantum mechanics that was originated from 't Hooft's analysis on dissipation and quantization. In this work we carry out a NC algebra analysis of the Friedmann-Robert-Walker model, coupled to a perfect fluid and in the presence of a cosmological constant. The classical field equations are modified, by the introduction of a shift operator, in order to introduce noncommutativity in these models. (author)

  6. Reachability for Finite-state Process Algebras Using Horn Clauses

    DEFF Research Database (Denmark)

    Skrypnyuk, Nataliya; Nielson, Flemming

    2013-01-01

    In this work we present an algorithm for solving the reachability problem in finite systems that are modelled with process algebras. Our method is based on Static Analysis, in particular, Data Flow Analysis, of the syntax of a process algebraic system with multi-way synchronisation. The results of...... encountered or it is not in the least model for all constructed states and thus is definitely unreachable. The advantages of the algorithm are that in many cases only a part of the Labelled Transition System will be built which leads to lower time and memory consumption. Also, it is not necessary to save all...

  7. Markov chains models, algorithms and applications

    CERN Document Server

    Ching, Wai-Ki; Ng, Michael K; Siu, Tak-Kuen

    2013-01-01

    This new edition of Markov Chains: Models, Algorithms and Applications has been completely reformatted as a text, complete with end-of-chapter exercises, a new focus on management science, new applications of the models, and new examples with applications in financial risk management and modeling of financial data.This book consists of eight chapters.  Chapter 1 gives a brief introduction to the classical theory on both discrete and continuous time Markov chains. The relationship between Markov chains of finite states and matrix theory will also be highlighted. Some classical iterative methods

  8. New solutions from algebraic equations for the Skyrme model coupled to a scalar meson

    Energy Technology Data Exchange (ETDEWEB)

    Braghin, Fabio L. [Universidade Federal do Rio Grande do Norte (IIF/UFRN), Natal, RN (Brazil). Inst. Internacional de Fisica

    2010-07-01

    Full text: In this work a modified Skyrme model is considered such as to incorporate the interaction of the hedgehog with a scalar field, based on a previous work. The Skyrme model is a model of the nucleon in which the baryon emerges as a topological soliton and its coupling to a scalar field can either correspond to the coupling to the lightest scalar isoscalar meson sigma and also to implement the spontaneous breakdown of chiral symmetry in a consistent way. Therefore it can be related to modifications of a dense interacting medium and it becomes suitable for investigating the role of the symmetry breaking and its restoration. A transcendental algebraic equation is found to be enough to extract a new class of profile solutions of the skyrmion in a constant background. The mass of the corresponding topological soliton was found to decrease considerably in the case small masses are associated to the scalar field. (author)

  9. Algebraic turbulent heat flux model for prediction of thermal stratification in piping system

    International Nuclear Information System (INIS)

    The effect of stratification on the flow in bounded geometries is studied through computational fluid dynamics (CFD) and two different modeling of the turbulent heat flux, namely constant turbulent Prandtl number and Algebraic Heat Flux Model (AHFM). The main feature of the work is the evaluation of the effect of buoyancy on the thermal quantities, velocity field and related pressure drop. It has been stated the superiority of the AHFM for the evaluation of turbulent heat flux and temperature field together with a correct evaluation of the thickness of the thermal layer (i.e stratification persistence), in comparison with the simple eddy diffusivity approach. However the adopted model shows over-prediction of the momentum transport in the vertical direction in comparison with the experimental data introducing higher uncertainties for the obtained pressure drop and related Fanning friction factor. (author)

  10. A new class of Matrix Models arising from the W-infinity Algebra

    CERN Document Server

    Herce, H D; Herce, Henry D.; Zemba, Guillermo R.

    2002-01-01

    We present a new class of hermitian one-matrix models originated in the W-infinity algebra: more precisely, the polynomials defining the W-infinity generators in their fermionic bilinear form are shown to expand the orthogonal basis of a class of random hermitian matrix models. The corresponding potentials are given, and the thermodynamic limit interpreted in terms of a simple plasma picture. The new matrix models can be successfully applied to the full bosonization of interesting one-dimensional systems, including all the perturbative orders in the inverse size of the system. As a simple application, we present the all-order bosonization of the free fermionic field on the one-dimensional lattice.

  11. Algorithms and Models For Combinatorial Optimization Problems

    OpenAIRE

    Fernandes Muritiba, Albert Einstein

    2010-01-01

    In this thesis we present some combinatorial optimization problems, suggest models and algorithms for their effective solution. For each problem,we give its description, followed by a short literature review, provide methods to solve it and, finally, present computational results and comparisons with previous works to show the effectiveness of the proposed approaches. The considered problems are: the Generalized Traveling Salesman Problem (GTSP), the Bin Packing Problem with Conflicts(BPPC) a...

  12. MATLAB matrix algebra

    CERN Document Server

    Pérez López, César

    2014-01-01

    MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Matrix Algebra introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. Starting with a look at symbolic and numeric variables, with an emphasis on vector and matrix variables, you will go on to examine functions and operations that support vectors and matrices as arguments, including those based on analytic parent functions. Computational methods for finding eigenvalues and eigenvectors of matrices are detailed, leading to various matrix decompositions. Applications such as change of bases, the classification of quadratic forms and ...

  13. A note on the "logarithmic-W_3" octuplet algebra and its Nichols algebra

    OpenAIRE

    Semikhatov, A M

    2013-01-01

    We describe a Nichols-algebra-motivated construction of an octuplet chiral algebra that is a "W_3-counterpart" of the triplet algebra of (p,1) logarithmic models of two-dimensional conformal field theory.

  14. Meadow enriched ACP process algebras

    NARCIS (Netherlands)

    J.A. Bergstra; C.A. Middelburg

    2009-01-01

    We introduce the notion of an ACP process algebra. The models of the axiom system ACP are the origin of this notion. ACP process algebras have to do with processes in which no data are involved. We also introduce the notion of a meadow enriched ACP process algebra, which is a simple generalization o

  15. Arrangement Computation for Planar Algebraic Curves

    OpenAIRE

    Berberich, Eric; Emeliyanenko, Pavel; Kobel, Alexander; Sagraloff, Michael

    2011-01-01

    We present a new certified and complete algorithm to compute arrangements of real planar algebraic curves. Our algorithm provides a geometric-topological analysis of the decomposition of the plane induced by a finite number of algebraic curves in terms of a cylindrical algebraic decomposition of the plane. Compared to previous approaches, we improve in two main aspects: Firstly, we significantly reduce the amount of exact operations, that is, our algorithms only uses resultant and gcd as pure...

  16. Comparing Cognitive Models of Domain Mastery and Task Performance in Algebra: Validity Evidence for a State Assessment

    Science.gov (United States)

    Warner, Zachary B.

    2013-01-01

    This study compared an expert-based cognitive model of domain mastery with student-based cognitive models of task performance for Integrated Algebra. Interpretations of student test results are limited by experts' hypotheses of how students interact with the items. In reality, the cognitive processes that students use to solve each item may be…

  17. Performance of a parallel algebraic multilevel preconditioner for stabilized finite element semiconductor device modeling

    International Nuclear Information System (INIS)

    In this study results are presented for the large-scale parallel performance of an algebraic multilevel preconditioner for solution of the drift-diffusion model for semiconductor devices. The preconditioner is the key numerical procedure determining the robustness, efficiency and scalability of the fully-coupled Newton-Krylov based, nonlinear solution method that is employed for this system of equations. The coupled system is comprised of a source term dominated Poisson equation for the electric potential, and two convection-diffusion-reaction type equations for the electron and hole concentration. The governing PDEs are discretized in space by a stabilized finite element method. Solution of the discrete system is obtained through a fully-implicit time integrator, a fully-coupled Newton-based nonlinear solver, and a restarted GMRES Krylov linear system solver. The algebraic multilevel preconditioner is based on an aggressive coarsening graph partitioning of the nonzero block structure of the Jacobian matrix. Representative performance results are presented for various choices of multigrid V-cycles and W-cycles and parameter variations for smoothers based on incomplete factorizations. Parallel scalability results are presented for solution of up to 108 unknowns on 4096 processors of a Cray XT3/4 and an IBM POWER eServer system.

  18. On various avatars of the Pasquier algebra

    International Nuclear Information System (INIS)

    A Pasquier algebra is a commutative associative algebra of normal matrices attached to a graph. I review various appearances of such algebras in different contexts: operator product algebras and structure constants in conformal theories and lattice models, integrable N = 2 supersymmetric models and their topological partners. (author)

  19. Sparse modeling theory, algorithms, and applications

    CERN Document Server

    Rish, Irina

    2014-01-01

    ""A comprehensive, clear, and well-articulated book on sparse modeling. This book will stand as a prime reference to the research community for many years to come.""-Ricardo Vilalta, Department of Computer Science, University of Houston""This book provides a modern introduction to sparse methods for machine learning and signal processing, with a comprehensive treatment of both theory and algorithms. Sparse Modeling is an ideal book for a first-year graduate course.""-Francis Bach, INRIA - École Normale Supřieure, Paris

  20. Conceptual Explanation for the Algebra in the Noncommutative Approach to the Standard Model

    Science.gov (United States)

    Chamseddine, Ali H.; Connes, Alain

    2007-11-01

    The purpose of this Letter is to remove the arbitrariness of the ad hoc choice of the algebra and its representation in the noncommutative approach to the standard model, which was begging for a conceptual explanation. We assume as before that space-time is the product of a four-dimensional manifold by a finite noncommmutative space F. The spectral action is the pure gravitational action for the product space. To remove the above arbitrariness, we classify the irreducible geometries F consistent with imposing reality and chiral conditions on spinors, to avoid the fermion doubling problem, which amounts to have total dimension 10 (in the K-theoretic sense). It gives, almost uniquely, the standard model with all its details, predicting the number of fermions per generation to be 16, their representations and the Higgs breaking mechanism, with very little input.

  1. Two types of loop algebras and their expanding Lax integrable models

    Institute of Scientific and Technical Information of China (English)

    Yue Chao; Zhang Yu-Feng; Wei Yuan

    2007-01-01

    Though various integrable hierarchies of evolution equations were obtained by choosing proper U in zero-curvature equation Ut-Vx+[U,V]=0,but in this paper,a new integrable hierarchy possessing bi-Hamiltonian structure is worked out by selecting V with spectral potentials.Then its expanding Lax integrable model of the hierarchy possessing a simple Hamiltonian operator (J) is presented by constructing a subalgebra (G) of the loop algebra (A)2.As linear expansions of the above-mentioned integrable hierarchy and its expanding Lax integrable model with respect to their dimensional numbers,their (2+1)-dimensional forms are derived from a (2+1)-dimensional zero-curvature equation.

  2. Structure of $^{23}$Al from a multi-channel algebraic scattering model based on mirror symmetry

    CERN Document Server

    Fraser, P R; Massen-Hane, K; Amos, K; Canton, L; Karataglidis, S; van der Knijff, D; Bray, I

    2016-01-01

    The proton-rich nucleus $^{23}$Al has a ground state just 123 keV below the proton drip-line, and as a result comparatively little is known experimentally about its properties, as with many such nuclei. Theoretical investigations have tended to model exclusively the ground and first one to three excited states known. In this paper, we theoretically model most of the known spectrum, and predict what states may as yet be unobserved. We use the multichannel algebraic scattering (MCAS) method to describe states as resonances of a valence proton coupled to a $^{22}$Mg rotor core. Six states with low-excitation energies and defined $J^\\pi$ are matched, and we make the first prediction of the properties of four others and propound the possible existence of several more.

  3. Sensitivity analysis of groundwater flow model using the differential algebra method

    International Nuclear Information System (INIS)

    The techniques of sensitivity and uncertainty analyses are necessary for the performance assessment of the waste repositories and validations of mathematical and numerical models to determine key parameters in the models. An automated procedure is developed for performing large-scale sensitivity studies based on the use of computer tools. The procedure is composed of a FORTRAN precompiler called SANA and a preprocessor called PRESANA. The computer code SANA translates a FORTRAN code into its sensitivity analysis code using the Differential Algebra method, and the PRESANA is the computer tool to help the translation of the FORTRAN code. In this presentation, the automated procedure of sensitivity analysis and its application to the 3D-SEEP code which simulates 3-dimensional groundwater flow in the porous media are described. The sensitivity calculations for a sample problem are performed, and the applicability of SANA and PRESANA codes is discussed. 7 figs., 7 refs

  4. Structure of 23Al from a multi-channel algebraic scattering model based on mirror symmetry

    Science.gov (United States)

    Fraser, P. R.; Kadyrov, A. S.; Massen-Hane, K.; Amos, K.; Canton, L.; Karataglidis, S.; van der Knijff, D.; Bray, I.

    2016-09-01

    The proton-rich nucleus 23Al has a ground state just 123 keV below the one-proton emission threshold, and as a result comparatively little is known experimentally about its properties, as with many such nuclei. Theoretical investigations have tended to model exclusively the ground and first one to three excited states known. In this paper, we theoretically model most of the known spectrum, and predict what states may as yet be unobserved. We use the multichannel algebraic scattering method to describe states as resonances of a valence proton coupled to a 22Mg rotor core. Six states with low-excitation energies and defined {J}π are matched, and we make the first prediction of the properties of four others and propound the possible existence of several more.

  5. Multiscale modeling for classification of SAR imagery using hybrid EM algorithm and genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    Xianbin Wen; Hua Zhang; Jianguang Zhang; Xu Jiao; Lei Wang

    2009-01-01

    A novel method that hybridizes genetic algorithm (GA) and expectation maximization (EM) algorithm for the classification of syn-thetic aperture radar (SAR) imagery is proposed by the finite Gaussian mixtures model (GMM) and multiscale autoregressive (MAR)model. This algorithm is capable of improving the global optimality and consistency of the classification performance. The experiments on the SAR images show that the proposed algorithm outperforms the standard EM method significantly in classification accuracy.

  6. On Generalized Clifford Algebras and Spin Lattice Systems

    International Nuclear Information System (INIS)

    The incessantly growing area of applications of Clifford algebras and naturalness of their use in formulating problems for direct calculation entitles one to call them Clifford numbers. The generalized ''universal'' Clifford numbers are here introduced via k-ubic form Qk replacing quadratic one in familiar construction of an appropriate ideal of tensor algebra. One of the epimorphic images of universal algebras k - Cn = T(V)/I(Qk) is the algebra Cln(k) with n generators and these are the algebras to be used here. Because generalized Clifford algebras Cln(k) possess inherent Zk x Zk x Λ XZk grading - this makes them an efficient apparatus to deal with spin lattice systems. This efficiency is illustrated here by derivation of two major observations. Namely - partition functions for vector and planar Potts models and other model with Zn invariant Hamiltonian are polynomials in generalized hyperbolic functions of the n-th order. Secondly, the problem of algorithmic calculation of the partition function for any vector Potts model as treated here is reduced to the calculation of Tr(γi1..γis ), where γ's are the generators of the generalized Clifford algebra. Finally the expression for Tr(γi1..γis), for arbitrary collection of such y matrices is derived. (author)

  7. Form factors in sinh- and sine-Gordon models, deformed Virasoro algebra, Macdonald polynomials and resonance identities

    International Nuclear Information System (INIS)

    We continue the study of form factors of descendant operators in the sinh- and sine-Gordon models in the framework of the algebraic construction proposed in [1]. We find the algebraic construction to be related to a particular limit of the tensor product of the deformed Virasoro algebra and a suitably chosen Heisenberg algebra. To analyze the space of local operators in the framework of the form factor formalism we introduce screening operators and construct singular and cosingular vectors in the Fock spaces related to the free field realization of the obtained algebra. We show that the singular vectors are expressed in terms of the degenerate Macdonald polynomials with rectangular partitions. We study the matrix elements that contain a singular vector in one chirality and a cosingular vector in the other chirality and find them to lead to the resonance identities already known in the conformal perturbation theory. Besides, we give a new derivation of the equation of motion in the sinh-Gordon theory, and a new representation for conserved currents

  8. W-algebras, new rational models and completeness of the c=1 classification

    International Nuclear Information System (INIS)

    Two series of W-algebras with two generators are constructed from chiral vertex operators of a free field representation. If c=1-24k, there exists a W(2,3k) algebra for k element of Z+/2 and a W(2,8k) algebra for k element of Z+/4. All possible lowest-weight representations, their characters and fusion rules are calculated proving that these theories are rational. It is shown, that these non-unitary theories complete the classification of all rational theories with effective central charge ceff=1. The results are generalized to the case of extended supersymmetric conformal algebras. (orig.)

  9. W-algebras, new rational models and completeness of the c=1 classification

    International Nuclear Information System (INIS)

    Two series of W-algebras with two generators are constructed from chiral vertex operators of a free field representation. If c = 1 - 24 k, there exists a W(2,3k) algebra for kelement of Z+/2 and a W (2,8k) algebra for k element of Z+/4. All possible lowest-weight representations, their characters and fusion rules are calculated proving that these therories are rational. It is shown, that these non-unitary theories complete the classification of all rational therories with effective central charge ceff = 1. The results are generalized to the case of extended supersymmetric conformal algebras. (orig.)

  10. Operators and representation theory canonical models for algebras of operators arising in quantum mechanics

    CERN Document Server

    Jorgensen, PET

    1987-01-01

    Historically, operator theory and representation theory both originated with the advent of quantum mechanics. The interplay between the subjects has been and still is active in a variety of areas.This volume focuses on representations of the universal enveloping algebra, covariant representations in general, and infinite-dimensional Lie algebras in particular. It also provides new applications of recent results on integrability of finite-dimensional Lie algebras. As a central theme, it is shown that a number of recent developments in operator algebras may be handled in a particularly e

  11. On the algebraic theory of kink sectors: Application to quantum field theory models and collision theory

    International Nuclear Information System (INIS)

    Several two dimensional quantum field theory models have more than one vacuum state. An investigation of super selection sectors in two dimensions from an axiomatic point of view suggests that there should be also states, called soliton or kink states, which interpolate different vacua. Familiar quantum field theory models, for which the existence of kink states have been proven, are the Sine-Gordon and the φ42-model. In order to establish the existence of kink states for a larger class of models, we investigate the following question: Which are sufficient conditions a pair of vacuum states has to fulfill, such that an interpolating kink state can be constructed? We discuss the problem in the framework of algebraic quantum field theory which includes, for example, the P(φ)2-models. We identify a large class of vacuum states, including the vacua of the P(φ)2-models, the Yukawa2-like models and special types of Wess-Zumino models, for which there is a natural way to construct an interpolating kink state. In two space-time dimensions, massive particle states are kink states. We apply the Haag-Ruelle collision theory to kink sectors in order to analyze the asymptotic scattering states. We show that for special configurations of n kinks the scattering states describe n freely moving non interacting particles. (orig.)

  12. Poisson bracket algebra for chiral group elements in the WZNW model

    CERN Document Server

    Bimonte, G; Simoni, A; Stern, A

    1992-01-01

    We examine the Wess-Zumino-Novikov-Witten (WZNW) model on a circle and compute the Poisson bracket algebra for left and right moving chiral group elements. Our computations apply for arbitrary groups and boundary conditions, the latter being characterized by the monodromy matrix. Unlike in previous treatments, they do not require specifying a particular parametrization of the group valued fields in terms of angles spanning the group. We do however find it necessary to make a gauge choice, as the chiral group elements are not gauge invariant observables. (On the other hand, the quadratic form of the Poisson brackets may be defined independent of a gauge fixing.) Gauge invariant observables can be formed from the monodromy matrix and these observables are seen to commute in the quantum theory.

  13. Approach method of the solutions of algebraic models of the N body problem

    International Nuclear Information System (INIS)

    We have studied a class of algebraic eigenvalue problems that generate tridiagonal matrices. The Lipkin Hamiltonian was chosen as representative. Three methods have been implemented, whose extension to more general many body problems seems possible i) Degenerate Linked Cluster Theory (LCT), which disregards special symmetries of the interaction and defines a hierarchy of approximation based on model spaces at fixed number of particle-hole excitation of the unperturbed Hamiltonian. The method works for small perturbations but does not yield a complete description. ii) A new linearization method that replaces the matrix to be diagonalized by local (tangent) approximations by harmonic matrices. This method generalizes LCT and is a posteriori reminiscent of semi-classical ones. However of is simpler, more precise and yields a complete description of spectra. iii) A global way to characterize spectra based on Gershgorine-Hadamard disks

  14. Algebraic geometry methods associated to the one-dimensional Hubbard model

    Science.gov (United States)

    Martins, M. J.

    2016-06-01

    In this paper we study the covering vertex model of the one-dimensional Hubbard Hamiltonian constructed by Shastry in the realm of algebraic geometry. We show that the Lax operator sits in a genus one curve which is not isomorphic but only isogenous to the curve suitable for the AdS/CFT context. We provide an uniformization of the Lax operator in terms of ratios of theta functions allowing us to establish relativistic like properties such as crossing and unitarity. We show that the respective R-matrix weights lie on an Abelian surface being birational to the product of two elliptic curves with distinct J-invariants. One of the curves is isomorphic to that of the Lax operator but the other is solely fourfold isogenous. These results clarify the reason the R-matrix can not be written using only difference of spectral parameters of the Lax operator.

  15. Poisson bracket algebra for chiral group elements in the WZNW model

    International Nuclear Information System (INIS)

    In this paper, the authors examine the Wess-Zumino-Novikov-Witten (WZNW) model on a circle and compute the Poisson bracket algebra for left- and right-moving chiral group elements. The authors' computations apply for arbitrary groups and arbitrary boundary conditions, the latter being characterized by the monodromy matrix. Unlike previous treatments, the Poisson brackets do not require specifying a particular parametrization of the group valued fields in terms of angles spanning the group. The authors do however find it necessary to make a gauge choice, as the chiral group elements are not gauge invariant observables. (On the other hand, the quadratic form of the Poisson brackets may be defined independently of a gauge fixing.) Gauge invariant observables can be formed from the monodromy matrix and these observbles are seen to commute in the quantum theory

  16. Particle-hole symmetry in algebraic Bethe Ansatz for the XXX model

    International Nuclear Information System (INIS)

    It is well known that the space of all quantum states of the XXX model for a magnetic ring of N nodes, each with the spin 1/2, decomposes into sectors with r spin deviations, r = 0,1, 2,..., N [1, 2, 3, 4]. The sectors r and N - r are related mutually by the particle-hole transformation which exchanges the signs + and - on each node. We discuss here effects of this transformation on the formalism of algebraic Bethe Ansatz, in particular on the form of the monodromy matrix, the main tool of this formalism. We derive explicitly appropriate transformation rules for CN- orbits of magnetic configurations and the corresponding Fourier transformations within the bases of wavelets. In particular, we point out some important phase relations between orbits on both sides of the equator.

  17. New insights in the standard model of quantum physics in Clifford algebra

    CERN Document Server

    Daviau, Claude

    2013-01-01

    Why Clifford algebra is the true mathematical frame of the standard model of quantum physics. Why the time is everywhere oriented and why the left side shall never become the right side. Why positrons have also a positive proper energy. Why there is a Planck constant. Why a mass is not a charge. Why a system of particles implies the existence of the inverse of the individual wave function. Why a fourth neutrino should be a good candidate for black matter. Why concepts as “parity” and “reverse” are essential. Why the electron of a H atom is in only one bound state. Plus 2 very remarkable identities, and the invariant wave equations that they imply. Plus 3 generations and 4 neutrinos. Plus 5 dimensions in the space and 6 dimensions in space-time…

  18. Algebraic Signal Processing Theory

    OpenAIRE

    Pueschel, Markus; Moura, Jose M. F.

    2006-01-01

    This paper presents an algebraic theory of linear signal processing. At the core of algebraic signal processing is the concept of a linear signal model defined as a triple (A, M, phi), where familiar concepts like the filter space and the signal space are cast as an algebra A and a module M, respectively, and phi generalizes the concept of the z-transform to bijective linear mappings from a vector space of, e.g., signal samples, into the module M. A signal model provides the structure for a p...

  19. Study of Transitions in the Atmospheric Boundary Layer Using Explicit Algebraic Turbulence Models

    Science.gov (United States)

    Lazeroms, W. M. J.; Svensson, G.; Bazile, E.; Brethouwer, G.; Wallin, S.; Johansson, A. V.

    2016-08-01

    We test a recently developed engineering turbulence model, a so-called explicit algebraic Reynolds-stress (EARS) model, in the context of the atmospheric boundary layer. First of all, we consider a stable boundary layer used as the well-known first test case from the Global Energy and Water Cycle Experiment Atmospheric Boundary Layer Study (GABLS1). The model is shown to agree well with data from large-eddy simulations (LES), and this agreement is significantly better than for a standard operational scheme with a prognostic equation for turbulent kinetic energy. Furthermore, we apply the model to a case with a (idealized) diurnal cycle and make a qualitative comparison with a simpler first-order model. Some interesting features of the model are highlighted, pertaining to its stronger foundation on physical principles. In particular, the use of more prognostic equations in the model is shown to give a more realistic dynamical behaviour. This qualitative study is the first step towards a more detailed comparison, for which additional LES data are needed.

  20. An algebraic pairing model with Sp(4) symmetry and its deformation

    International Nuclear Information System (INIS)

    A fermion realization of the compact symplectic sp(4) algebra provides a natural framework for studying isovector-pairing correlations in nuclei. While these correlations manifest themselves most clearly in the binding energies of 0+ ground states, they also have a large effect on the energies of excited states, including especially excited 0+ states. In this paper, we consider non-deformed as well as deformed algebraic descriptions of pairing through the reductions of sp(q)(4) to different realizations of u(q)(2) for single-j and multi-j orbitals. The model yields a classification scheme for completely paired 0+ states of even-even and odd-odd nuclei in the 1d3/2, 1f7/2 and 1f5/2 2p1/2 2p3/2 1g9/2 shells. Phenomenological non-deformed and deformed isospin-breaking Hamiltonians are expressed in terms of the generators of the dynamical symmetry groups Sp(4) and Spq(4). These Hamiltonians are related to the most general microscopic pairing problem, including isovector pairing and isoscalar proton-neutron interaction along with nonlinear interaction in the deformed extension. In both the non-deformed and deformed cases the eigenvalues of the Hamiltonian are fit to the relevant Coulomb corrected experimental 0+ energies and this, in turn, allows us to estimate the interaction strength parameters, to investigate isovector-pairing properties and symmetries breaking and to predict the corresponding energies. While the non-deformed theory yields results that are comparable to other theories for light nuclei, the deformed extension, which takes into account higher order interactions between the particles, gives a better fit to the data. The multi-shell applications of the model provide for reasonable predictions of energies of exotic nuclei

  1. Link mining models, algorithms, and applications

    CERN Document Server

    Yu, Philip S; Faloutsos, Christos

    2010-01-01

    This book presents in-depth surveys and systematic discussions on models, algorithms and applications for link mining. Link mining is an important field of data mining. Traditional data mining focuses on 'flat' data in which each data object is represented as a fixed-length attribute vector. However, many real-world data sets are much richer in structure, involving objects of multiple types that are related to each other. Hence, recently link mining has become an emerging field of data mining, which has a high impact in various important applications such as text mining, social network analysi

  2. Genetic Algorithms Principles Towards Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    Nabil M. Hewahi

    2011-10-01

    Full Text Available In this paper we propose a general approach based on Genetic Algorithms (GAs to evolve Hidden Markov Models (HMM. The problem appears when experts assign probability values for HMM, they use only some limited inputs. The assigned probability values might not be accurate to serve in other cases related to the same domain. We introduce an approach based on GAs to find
    out the suitable probability values for the HMM to be mostly correct in more cases than what have been used to assign the probability values.

  3. Killing scalar of non-linear σ-model on G/H realizing the classical exchange algebra

    International Nuclear Information System (INIS)

    The Poisson brackets for non-linear σ-models on G/H are set up on the light-like plane. A quantity which transforms irreducibly by the Killing vectors, called Killing scalar, is constructed in an arbitrary representation of G. It is shown to satisfy the classical exchange algebra

  4. Algebraic cohomology versus topological cohomology in constructing the Wess-Zumino term of the σ-model

    International Nuclear Information System (INIS)

    The construction of an invariant action of the σ-model based on relative Lie algebra cohomology is discussed and compared with the conventional topological interpretation. An example of the Wess-Zumino term for a topologically trivial target space is given. (orig.)

  5. Algebraic multigrid preconditioning within parallel finite-element solvers for 3-D electromagnetic modelling problems in geophysics

    Science.gov (United States)

    Koldan, Jelena; Puzyrev, Vladimir; de la Puente, Josep; Houzeaux, Guillaume; Cela, José María

    2014-06-01

    We present an elaborate preconditioning scheme for Krylov subspace methods which has been developed to improve the performance and reduce the execution time of parallel node-based finite-element (FE) solvers for 3-D electromagnetic (EM) numerical modelling in exploration geophysics. This new preconditioner is based on algebraic multigrid (AMG) that uses different basic relaxation methods, such as Jacobi, symmetric successive over-relaxation (SSOR) and Gauss-Seidel, as smoothers and the wave front algorithm to create groups, which are used for a coarse-level generation. We have implemented and tested this new preconditioner within our parallel nodal FE solver for 3-D forward problems in EM induction geophysics. We have performed series of experiments for several models with different conductivity structures and characteristics to test the performance of our AMG preconditioning technique when combined with biconjugate gradient stabilized method. The results have shown that, the more challenging the problem is in terms of conductivity contrasts, ratio between the sizes of grid elements and/or frequency, the more benefit is obtained by using this preconditioner. Compared to other preconditioning schemes, such as diagonal, SSOR and truncated approximate inverse, the AMG preconditioner greatly improves the convergence of the iterative solver for all tested models. Also, when it comes to cases in which other preconditioners succeed to converge to a desired precision, AMG is able to considerably reduce the total execution time of the forward-problem code-up to an order of magnitude. Furthermore, the tests have confirmed that our AMG scheme ensures grid-independent rate of convergence, as well as improvement in convergence regardless of how big local mesh refinements are. In addition, AMG is designed to be a black-box preconditioner, which makes it easy to use and combine with different iterative methods. Finally, it has proved to be very practical and efficient in the

  6. Motion Model Employment using interacting Motion Model Algorithm

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar

    2006-01-01

    The paper presents a simulation study to track a maneuvering target using a selective approach in choosing Interacting Multiple Models (IMM) algorithm to provide a wider coverage to track such targets.  Initially, there are two motion models in the system to track a target.  Probability of each m...

  7. Computational algebraic geometry for statistical modeling FY09Q2 progress.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David C.; Rojas, Joseph Maurice; Pebay, Philippe Pierre

    2009-03-01

    This is a progress report on polynomial system solving for statistical modeling. This is a progress report on polynomial system solving for statistical modeling. This quarter we have developed our first model of shock response data and an algorithm for identifying the chamber cone containing a polynomial system in n variables with n+k terms within polynomial time - a significant improvement over previous algorithms, all having exponential worst-case complexity. We have implemented and verified the chamber cone algorithm for n+3 and are working to extend the implementation to handle arbitrary k. Later sections of this report explain chamber cones in more detail; the next section provides an overview of the project and how the current progress fits into it.

  8. Models and Algorithms for Tracking Target with Coordinated Turn Motion

    Directory of Open Access Journals (Sweden)

    Xianghui Yuan

    2014-01-01

    Full Text Available Tracking target with coordinated turn (CT motion is highly dependent on the models and algorithms. First, the widely used models are compared in this paper—coordinated turn (CT model with known turn rate, augmented coordinated turn (ACT model with Cartesian velocity, ACT model with polar velocity, CT model using a kinematic constraint, and maneuver centered circular motion model. Then, in the single model tracking framework, the tracking algorithms for the last four models are compared and the suggestions on the choice of models for different practical target tracking problems are given. Finally, in the multiple models (MM framework, the algorithm based on expectation maximization (EM algorithm is derived, including both the batch form and the recursive form. Compared with the widely used interacting multiple model (IMM algorithm, the EM algorithm shows its effectiveness.

  9. Multiple model updating using the finite element method over a polynomial algebra

    International Nuclear Information System (INIS)

    Vibration control is an important issue when it comes to preserving the structural integrity of mechanical structures, particularly in the case of lightweight structures found aboard flying vehicles, such as printed circuit boards. In order for a simulation to be effective, a suitable numerical model of the structure must be used. Such a model can be obtained using a model updating method, such as that which is presented in this work, based on the modified constitutive relation error principle. However, like many other model updating strategies, this method can be very expensive. When the structural parameters change over time, it would be too time consuming to perform another full calculation. In order to circumvent this problem, we introduce a new technique called the 'finite element method over a polynomial algebra', which involves modules defined over a ring of truncated polynomials in multiple variables. In this paper, we illustrate the method with the updating and reduction of a model of a beam instrumented with piezoelectric sensors and actuators, which are all taken into account in the numerical model. This is a simple problem, yet it is representative of the updating of printed circuit boards

  10. Algebraic Groups

    DEFF Research Database (Denmark)

    2007-01-01

    The workshop continued a series of Oberwolfach meetings on algebraic groups, started in 1971 by Tonny Springer and Jacques Tits who both attended the present conference. This time, the organizers were Michel Brion, Jens Carsten Jantzen, and Raphaël Rouquier. During the last years, the subject of...... algebraic groups (in a broad sense) has seen important developments in several directions, also related to representation theory and algebraic geometry. The workshop aimed at presenting some of these developments in order to make them accessible to a "general audience" of algebraic group-theorists, and to...

  11. A Multiple Model Approach to Modeling Based on LPF Algorithm

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Input-output data fitting methods are often used for unknown-structure nonlinear system modeling. Based on model-on-demand tactics, a multiple model approach to modeling for nonlinear systems is presented. The basic idea is to find out, from vast historical system input-output data sets, some data sets matching with the current working point, then to develop a local model using Local Polynomial Fitting (LPF) algorithm. With the change of working points, multiple local models are built, which realize the exact modeling for the global system. By comparing to other methods, the simulation results show good performance for its simple, effective and reliable estimation.``

  12. Warehouse Optimization Model Based on Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Guofeng Qin

    2013-01-01

    Full Text Available This paper takes Bao Steel logistics automated warehouse system as an example. The premise is to maintain the focus of the shelf below half of the height of the shelf. As a result, the cost time of getting or putting goods on the shelf is reduced, and the distance of the same kind of goods is also reduced. Construct a multiobjective optimization model, using genetic algorithm to optimize problem. At last, we get a local optimal solution. Before optimization, the average cost time of getting or putting goods is 4.52996 s, and the average distance of the same kinds of goods is 2.35318 m. After optimization, the average cost time is 4.28859 s, and the average distance is 1.97366 m. After analysis, we can draw the conclusion that this model can improve the efficiency of cargo storage.

  13. Adaptive numerical algorithms in space weather modeling

    Science.gov (United States)

    Tóth, Gábor; van der Holst, Bart; Sokolov, Igor V.; De Zeeuw, Darren L.; Gombosi, Tamas I.; Fang, Fang; Manchester, Ward B.; Meng, Xing; Najib, Dalal; Powell, Kenneth G.; Stout, Quentin F.; Glocer, Alex; Ma, Ying-Juan; Opher, Merav

    2012-02-01

    Space weather describes the various processes in the Sun-Earth system that present danger to human health and technology. The goal of space weather forecasting is to provide an opportunity to mitigate these negative effects. Physics-based space weather modeling is characterized by disparate temporal and spatial scales as well as by different relevant physics in different domains. A multi-physics system can be modeled by a software framework comprising several components. Each component corresponds to a physics domain, and each component is represented by one or more numerical models. The publicly available Space Weather Modeling Framework (SWMF) can execute and couple together several components distributed over a parallel machine in a flexible and efficient manner. The framework also allows resolving disparate spatial and temporal scales with independent spatial and temporal discretizations in the various models. Several of the computationally most expensive domains of the framework are modeled by the Block-Adaptive Tree Solarwind Roe-type Upwind Scheme (BATS-R-US) code that can solve various forms of the magnetohydrodynamic (MHD) equations, including Hall, semi-relativistic, multi-species and multi-fluid MHD, anisotropic pressure, radiative transport and heat conduction. Modeling disparate scales within BATS-R-US is achieved by a block-adaptive mesh both in Cartesian and generalized coordinates. Most recently we have created a new core for BATS-R-US: the Block-Adaptive Tree Library (BATL) that provides a general toolkit for creating, load balancing and message passing in a 1, 2 or 3 dimensional block-adaptive grid. We describe the algorithms of BATL and demonstrate its efficiency and scaling properties for various problems. BATS-R-US uses several time-integration schemes to address multiple time-scales: explicit time stepping with fixed or local time steps, partially steady-state evolution, point-implicit, semi-implicit, explicit/implicit, and fully implicit

  14. Adaptive numerical algorithms in space weather modeling

    International Nuclear Information System (INIS)

    Space weather describes the various processes in the Sun–Earth system that present danger to human health and technology. The goal of space weather forecasting is to provide an opportunity to mitigate these negative effects. Physics-based space weather modeling is characterized by disparate temporal and spatial scales as well as by different relevant physics in different domains. A multi-physics system can be modeled by a software framework comprising several components. Each component corresponds to a physics domain, and each component is represented by one or more numerical models. The publicly available Space Weather Modeling Framework (SWMF) can execute and couple together several components distributed over a parallel machine in a flexible and efficient manner. The framework also allows resolving disparate spatial and temporal scales with independent spatial and temporal discretizations in the various models. Several of the computationally most expensive domains of the framework are modeled by the Block-Adaptive Tree Solarwind Roe-type Upwind Scheme (BATS-R-US) code that can solve various forms of the magnetohydrodynamic (MHD) equations, including Hall, semi-relativistic, multi-species and multi-fluid MHD, anisotropic pressure, radiative transport and heat conduction. Modeling disparate scales within BATS-R-US is achieved by a block-adaptive mesh both in Cartesian and generalized coordinates. Most recently we have created a new core for BATS-R-US: the Block-Adaptive Tree Library (BATL) that provides a general toolkit for creating, load balancing and message passing in a 1, 2 or 3 dimensional block-adaptive grid. We describe the algorithms of BATL and demonstrate its efficiency and scaling properties for various problems. BATS-R-US uses several time-integration schemes to address multiple time-scales: explicit time stepping with fixed or local time steps, partially steady-state evolution, point-implicit, semi-implicit, explicit/implicit, and fully implicit

  15. G/G gauged WZW-matter model, Bethe Ansatz for q-boson model and Commutative Frobenius algebra

    International Nuclear Information System (INIS)

    We investigate the correspondence between two dimensional topological gauge theories and quantum integrable systems discovered by Moore, Nekrasov, Shatashvili. This correspondence means that the hidden quantum integrable structure exists in the topological gauge theories. We showed the correspondence between the G/G gauged WZW model and the phase model in JHEP 11 (2012) 146 (arXiv:1209.3800). In this paper, we study a one-parameter deformation for this correspondence and show that the G/G gauged WZW model coupled to additional matters corresponds to the q-boson model. Furthermore, we investigate this correspondence from the viewpoint of the commutative Frobenius algebra, the axiom of the two dimensional topological quantum field theory

  16. G/G gauged WZW-matter model, Bethe Ansatz for q-boson model and Commutative Frobenius algebra

    Energy Technology Data Exchange (ETDEWEB)

    Okuda, Satoshi [Department of Physics, Rikkyo University,Toshima, Tokyo 171-8501 (Japan); Yoshida, Yutaka [High Energy Accelerator Research Organization (KEK),Tsukuba, Ibaraki 305-0801 (Japan)

    2014-03-03

    We investigate the correspondence between two dimensional topological gauge theories and quantum integrable systems discovered by Moore, Nekrasov, Shatashvili. This correspondence means that the hidden quantum integrable structure exists in the topological gauge theories. We showed the correspondence between the G/G gauged WZW model and the phase model in JHEP 11 (2012) 146 (arXiv:1209.3800). In this paper, we study a one-parameter deformation for this correspondence and show that the G/G gauged WZW model coupled to additional matters corresponds to the q-boson model. Furthermore, we investigate this correspondence from the viewpoint of the commutative Frobenius algebra, the axiom of the two dimensional topological quantum field theory.

  17. G/G gauged WZW-matter model, Bethe Ansatz for q-boson model and Commutative Frobenius algebra

    CERN Document Server

    Okuda, Satoshi

    2013-01-01

    We investigate the correspondence between two dimensional topological gauge theories and quantum integrable systems discovered by Moore, Nekrasov, Shatashvili. This correspondence means that the hidden quantum integrable structure exists in the topological gauge theories. We showed the correspondence between the G/G gauged WZW model and the phase model in JHEP 11 (2012) 146 (arXiv:1209.3800). In this paper, we study a one-parameter deformation for this correspondence and show that the G/G gauged WZW model coupled to additional matters corresponds to the q-boson model. Furthermore, we investigate this correspondence from a viewpoint of the commutative Frobenius algebra, the axiom of the two dimensional topological quantum field theory.

  18. Comparison of algebraic and analytical approaches to the formulation of the statistical model-based reconstruction problem for X-ray computed tomography.

    Science.gov (United States)

    Cierniak, Robert; Lorent, Anna

    2016-09-01

    The main aim of this paper is to investigate properties of our originally formulated statistical model-based iterative approach applied to the image reconstruction from projections problem which are related to its conditioning, and, in this manner, to prove a superiority of this approach over ones recently used by other authors. The reconstruction algorithm based on this conception uses a maximum likelihood estimation with an objective adjusted to the probability distribution of measured signals obtained from an X-ray computed tomography system with parallel beam geometry. The analysis and experimental results presented here show that our analytical approach outperforms the referential algebraic methodology which is explored widely in the literature and exploited in various commercial implementations. PMID:27289536

  19. Linear Algebra and Smarandache Linear Algebra

    OpenAIRE

    Vasantha, Kandasamy

    2003-01-01

    The present book, on Smarandache linear algebra, not only studies the Smarandache analogues of linear algebra and its applications, it also aims to bridge the need for new research topics pertaining to linear algebra, purely in the algebraic sense. We have introduced Smarandache semilinear algebra, Smarandache bilinear algebra and Smarandache anti-linear algebra and their fuzzy equivalents. Moreover, in this book, we have brought out the study of linear algebra and ve...

  20. Use of genetic algorithm for fitting Sovova's mass transfer model:

    OpenAIRE

    Hrnčič, Dejan; Mernik, Marjan; Knez Hrnčič, Maša

    2010-01-01

    A genetic algorithm with resizable population has been applied to the estimation of parameters for Sovovaćs mass transfer model. The comparison of results between a genetic algorithm and a global optimizer from the literatureshows that a genetic algorithm performs as good as or better than a global optimizer on a given set of problems. Other benefits of the genetic algorithm, for mass transfer modeling, are simplicity, robustness and efficiency.

  1. Sensitivity analysis of radionuclide transport model using the Differential Algebra method

    International Nuclear Information System (INIS)

    The technique of sensitivity analysis is necessary for the performance assessment of the waste repositories and validation of models to determine key parameters in the models. Because, the parameters of the models describe physical and chemical processes in geologic conditions are generally not well known. An automated procedure is developed for performing large-scale sensitivity studies based on the use of computer tools. The procedure is composed of a FORTRAN precompilar called SANA and a preprocessor called PRESANA. The SANA code translates a FORTRAN code into its sensitivity analysis code using the Differential Algebra method, and the PRESANA is the computer tool to help the translation of FORTRAN code. In this presentation, we describe the automated procedure of sensitivity analysis and its application to the radionuclide transport codes, and discuss the applicability of SANA and PRESANA codes. The UCB-NE-10.3 and Finite Element codes developed to simulate the migration of radionuclides in groundwater were chosen as the targets of this procedure. (author)

  2. Algebraic stress model for axial flow in a bare rod-bundle

    International Nuclear Information System (INIS)

    The problem of predicting transport properties for momentum and heat across the boundaries of interconnected channels has been the subject of many investigations. In the particular case of axial flow through rod-bundles, transport coefficients for channel faces aligned with rod centers are known to be considerably higher than those calculated by simple isotropic theories. And yet, it was been found that secondary flows play only a minor role in this overall transport, being turbulence highly enhanced across that hypothetical surface. In order to numerically predict the correct amount of the quantity being transported, the approach taken by many investigators was then to artificially increase the diffusion coefficient obtained via a simple isopropic theory (usually the standard k-ε model) and numerically match the correct experimentally observed mixing rates. The present paper reports an attempt to describe the turbulent stresses by means of an Algebraic Stress Model for turbulence. Relative turbulent kinetic energy distribution in all three directions are presented and compared with experiments in a square lattice. The strong directional dependence of transport terms are then obtained via a model for the Reynolds stresses. The results identify a need for a better representation of the mean-flow field part of the pressure-strain correlation term

  3. Segal algebras in commutative Banach algebras

    OpenAIRE

    INOUE, Jyunji; TAKAHASI, Sin-Ei

    2014-01-01

    The notion of Reiter's Segal algebra in commutative group algebras is generalized to a notion of Segal algebra in more general classes of commutative Banach algebras. Then we introduce a family of Segal algebras in commutative Banach algebras under considerations and study some properties of them.

  4. Algebra-Geometry of Piecewise Algebraic Varieties

    Institute of Scientific and Technical Information of China (English)

    Chun Gang ZHU; Ren Hong WANG

    2012-01-01

    Algebraic variety is the most important subject in classical algebraic geometry.As the zero set of multivariate splines,the piecewise algebraic variety is a kind generalization of the classical algebraic variety.This paper studies the correspondence between spline ideals and piecewise algebraic varieties based on the knowledge of algebraic geometry and multivariate splines.

  5. The algebraic structure of the Onsager algebra

    OpenAIRE

    DATE, ETSURO; Roan, Shi-shyr

    2000-01-01

    We study the Lie algebra structure of the Onsager algebra from the ideal theoretic point of view. A structure theorem of ideals in the Onsager algebra is obtained with the connection to the finite-dimensional representations. We also discuss the solvable algebra aspect of the Onsager algebra through the formal Lie algebra theory.

  6. Genetic Algorithm Approaches to Prebiobiotic Chemistry Modeling

    Science.gov (United States)

    Lohn, Jason; Colombano, Silvano

    1997-01-01

    We model an artificial chemistry comprised of interacting polymers by specifying two initial conditions: a distribution of polymers and a fixed set of reversible catalytic reactions. A genetic algorithm is used to find a set of reactions that exhibit a desired dynamical behavior. Such a technique is useful because it allows an investigator to determine whether a specific pattern of dynamics can be produced, and if it can, the reaction network found can be then analyzed. We present our results in the context of studying simplified chemical dynamics in theorized protocells - hypothesized precursors of the first living organisms. Our results show that given a small sample of plausible protocell reaction dynamics, catalytic reaction sets can be found. We present cases where this is not possible and also analyze the evolved reaction sets.

  7. Intertwining relations, asymmetric face model, and algebraic Bethe ansatz for SU{sub p,q}(2) invariant spin chain

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, A.G.; Chowdhury, A.R. [Jadavpur Univ., Calcutta (India)

    1996-08-01

    Intertwining relations for the quantum R-matrix of the SU{sub p,q}(2) invariant spin chain are obtained and the corresponding face model is deduced. An important difference is seen to arise due to the asymmetry generated by the parameters p and q, which leads to a asymmetric face model. An algebraic Bethe ansatz is set up and solved with the help of these intertwining vectors.

  8. A new, efficient algorithm for the Forest Fire Model

    OpenAIRE

    Pruessner, Gunnar; Jensen, Henrik Jeldtoft

    2003-01-01

    The Drossel-Schwabl Forest Fire Model is one of the best studied models of non-conservative self-organised criticality. However, using a new algorithm, which allows us to study the model on large statistical and spatial scales, it has been shown to lack simple scaling. We thereby show that the considered model is not critical. This paper presents the algorithm and its parallel implementation in detail, together with large scale numerical results for several observables. The algorithm can easi...

  9. Robot Control Based On Spatial-Operator Algebra

    Science.gov (United States)

    Rodriguez, Guillermo; Kreutz, Kenneth K.; Jain, Abhinandan

    1992-01-01

    Method for mathematical modeling and control of robotic manipulators based on spatial-operator algebra providing concise representation and simple, high-level theoretical frame-work for solution of kinematical and dynamical problems involving complicated temporal and spatial relationships. Recursive algorithms derived immediately from abstract spatial-operator expressions by inspection. Transition from abstract formulation through abstract solution to detailed implementation of specific algorithms to compute solution greatly simplified. Complicated dynamical problems like two cooperating robot arms solved more easily.

  10. W-algebras in conformal field theory

    International Nuclear Information System (INIS)

    Quantum W-algebras are defined and their relevance for conformal field theories is outlined. We describe direct constructions of W-algebras using associativity requirements. With this approach one explicitly obtains the first members of series of W-algebras, including in particular 'Casimir algebras' (related to simple Lie algebras) and extended symmetry algebras corresponding to special Virasoro-minimal models. We also describe methods for the study of highest weight representations of W-algebras. In some cases consistency of the corresponding quantum field theory already imposes severe restrictions on the admitted representations, i.e. allows to determine the field content. We conclude by reviewing known results on W-algebras and RCFTs and show that most known rational conformal fields theories can be described in terms of Casimir algebras although on the level of W-algebras exotic phenomena occur. (author). 40 refs

  11. A Clifford Algebra approach to the Discretizable Molecular Distance Geometry Problem

    OpenAIRE

    Andrioni, Alessandro

    2013-01-01

    The Discretizable Molecular Distance Geometry Problem (DMDGP) consists in a subclass of the Molecular Distance Geometry Problem for which an embedding in ${\\mathbb{R}^3}$ can be found using a Branch & Prune (BP) algorithm in a discrete search space. We propose a Clifford Algebra model of the DMDGP with an accompanying version of the BP algorithm.

  12. Coherent States and Schwinger Models for Pseudo Generalization of the Heisenberg Algebra

    Science.gov (United States)

    Fakhri, H.; Mojaveri, B.; Dehghani, A.

    We show that the non-Hermitian Hamiltonians of the simple harmonic oscillator with {PT} and {C} symmetries involve a pseudo generalization of the Heisenberg algebra via two pairs of creation and annihilation operators which are {T}-pseudo-Hermiticity and {P}-anti-pseudo-Hermiticity of each other. The non-unitary Heisenberg algebra is represented by each of the pair of the operators in two different ways. Consequently, the coherent and the squeezed coherent states are calculated in two different approaches. Moreover, it is shown that the approach of Schwinger to construct the su(2), su(1, 1) and sp(4, ℝ) unitary algebras is promoted so that unitary algebras with more linearly dependent number of generators are made.

  13. C*-index of observable algebras in G-spin model

    Institute of Scientific and Technical Information of China (English)

    JIANG; Lining

    2005-01-01

    In two-dimensional lattice spin systems in which the spins take values in a finite group G,one can define a field algebra F which carries an action of a Hopf algebra D(G),the double algebra of G and moreover,an action of D(G; H),which is a subalgebra of D(G) determined by a subgroup H of G,so that F becomes a modular algebra.The concrete construction of D(G; H)-invariant subspace AH in F is given.By constructing the quasi-basis of conditional expectation γG of AH onto AG,the C*-index of γG is exactly the index of H in G.

  14. An algebraic geometric model of an action of the face monoid associated to a Kac-Moody group on its building

    CERN Document Server

    Mokler, Claus

    2009-01-01

    The face monoid described in [M1] acts on the integrable highest weight modules of a symmetrizable Kac-Moody algebra. It has similar structural properties as a reductive algebraic monoid whose unit group is a Kac-Moody group. We found in [M5] two natural extensions of the action of the Kac-Moody group on its building to actions of the face monoid on the building. Now we give an algebraic geometric model of one of these actions of the face monoid. The building is obtained as a part of the spectrum of homogeneous prime ideals of the Cartan algebra of the Kac-Moody group. We describe the full spectrum of homogeneous prime ideals of the Cartan algebra.

  15. Bouc–Wen hysteresis model identification using Modified Firefly Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Zaman, Mohammad Asif, E-mail: zaman@stanford.edu [Department of Electrical Engineering, Stanford University (United States); Sikder, Urmita [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley (United States)

    2015-12-01

    The parameters of Bouc–Wen hysteresis model are identified using a Modified Firefly Algorithm. The proposed algorithm uses dynamic process control parameters to improve its performance. The algorithm is used to find the model parameter values that results in the least amount of error between a set of given data points and points obtained from the Bouc–Wen model. The performance of the algorithm is compared with the performance of conventional Firefly Algorithm, Genetic Algorithm and Differential Evolution algorithm in terms of convergence rate and accuracy. Compared to the other three optimization algorithms, the proposed algorithm is found to have good convergence rate with high degree of accuracy in identifying Bouc–Wen model parameters. Finally, the proposed method is used to find the Bouc–Wen model parameters from experimental data. The obtained model is found to be in good agreement with measured data. - Highlights: • We describe a new method to find the Bouc–Wen hysteresis model parameters. • We propose a Modified Firefly Algorithm. • We compare our method with existing methods to find that the proposed method performs better. • We use our model to fit experimental results. Good agreement is found.

  16. Bouc–Wen hysteresis model identification using Modified Firefly Algorithm

    International Nuclear Information System (INIS)

    The parameters of Bouc–Wen hysteresis model are identified using a Modified Firefly Algorithm. The proposed algorithm uses dynamic process control parameters to improve its performance. The algorithm is used to find the model parameter values that results in the least amount of error between a set of given data points and points obtained from the Bouc–Wen model. The performance of the algorithm is compared with the performance of conventional Firefly Algorithm, Genetic Algorithm and Differential Evolution algorithm in terms of convergence rate and accuracy. Compared to the other three optimization algorithms, the proposed algorithm is found to have good convergence rate with high degree of accuracy in identifying Bouc–Wen model parameters. Finally, the proposed method is used to find the Bouc–Wen model parameters from experimental data. The obtained model is found to be in good agreement with measured data. - Highlights: • We describe a new method to find the Bouc–Wen hysteresis model parameters. • We propose a Modified Firefly Algorithm. • We compare our method with existing methods to find that the proposed method performs better. • We use our model to fit experimental results. Good agreement is found

  17. College algebra

    CERN Document Server

    Kolman, Bernard

    1985-01-01

    College Algebra, Second Edition is a comprehensive presentation of the fundamental concepts and techniques of algebra. The book incorporates some improvements from the previous edition to provide a better learning experience. It provides sufficient materials for use in the study of college algebra. It contains chapters that are devoted to various mathematical concepts, such as the real number system, the theory of polynomial equations, exponential and logarithmic functions, and the geometric definition of each conic section. Progress checks, warnings, and features are inserted. Every chapter c

  18. Zonotopal algebra

    OpenAIRE

    Holtz, Olga; Ron, Amos

    2007-01-01

    A wealth of geometric and combinatorial properties of a given linear endomorphism $X$ of $\\R^N$ is captured in the study of its associated zonotope $Z(X)$, and, by duality, its associated hyperplane arrangement ${\\cal H}(X)$. This well-known line of study is particularly interesting in case $n\\eqbd\\rank X \\ll N$. We enhance this study to an algebraic level, and associate $X$ with three algebraic structures, referred herein as {\\it external, central, and internal.} Each algebraic structure is ...

  19. Hom-Akivis algebras

    OpenAIRE

    Issa, A. Nourou

    2010-01-01

    Hom-Akivis algebras are introduced. The commutator-Hom-associator algebra of a non-Hom-associative algebra (i.e. a Hom-nonassociative algebra) is a Hom-Akivis algebra. It is shown that non-Hom-associative algebras can be obtained from nonassociative algebras by twisting along algebra automorphisms while Hom-Akivis algebras can be obtained from Akivis algebras by twisting along algebra endomorphisms. It is pointed out that a Hom-Akivis algebra associated to a Hom-alternative algebra is a Hom-M...

  20. Algorithm for Realistic Modeling of Graphitic Systems

    Directory of Open Access Journals (Sweden)

    A.V. Khomenko

    2011-01-01

    Full Text Available An algorithm for molecular dynamics simulations of graphitic systems using realistic semiempirical interaction potentials of carbon atoms taking into account both short-range and long-range contributions is proposed. Results of the use of the algorithm for a graphite sample are presented. The scalability of the algorithm depending on the system size and the number of processor cores involved in the calculations is analyzed.

  1. Dimensionally Distributed Learning: Models and Algorithm

    OpenAIRE

    Zheng, Haipeng; Kulkarni, Sanjeev R.; Poor, H. Vincent

    2008-01-01

    This paper introduces a framework for regression with dimensionally distributed data with a fusion center. A cooperative learning algorithm, the iterative conditional expectation algorithm (ICEA), is designed within this framework. The algorithm can effectively discover linear combinations of individual estimators trained by each agent without transferring and storing large amount of data amongst the agents and the fusion center. The convergence of ICEA is explored. Specifically, for a two ag...

  2. The bees algorithm: Modelling nature to solve complex optimisation problems

    OpenAIRE

    Pham, Duc; Le-Thi, Hoai; Castellani, Marco

    2013-01-01

    The Bees Algorithm models the foraging behaviour of honey bees in order to solve optimisation problems. The algorithm performs a kind of exploitative neighbourhood search combined with random explorative search. This paper describes the Bees Algorithm and presents two application examples: the training of neural networks to predict the energy efficiency of buildings, and the solution of the protein folding problem. The Bees Algorithm proved its effectiveness and speed, and obtained very compe...

  3. Super Lie n-algebra extensions, higher WZW models, and super p-branes with tensor multiplet fields

    CERN Document Server

    Fiorenza, Domenico; Schreiber, Urs

    2013-01-01

    We formalize higher dimensional and higher gauge WZW-type sigma-model local prequantum field theory, and discuss its rationalized/perturbative description in (super-)Lie n-algebra homotopy theory (the true home of the "FDA"-language used in the supergravity literature). We show generally how the intersection laws for such higher WZW-type sigma-model branes (open brane ending on background brane) are encoded precisely in (super-) L-infinity-extension theory and how the resulting "extended (super-)spacetimes" formalize spacetimes containing sigma model brane condensates. As an application we prove in Lie n-algebra homotopy theory that the complete super p-brane spectrum of superstring/M-theory is realized this way, including the pure sigma-model branes (the "old brane scan") but also the branes with tensor multiplet worldvolume fields, notably the D-branes and the M5-brane. For instance the degree-0 piece of the higher symmetry algebra of 11-dimensional spacetime with an M2-brane condensate turns out to be the ...

  4. Mathematical Models of the Simplest Fuzzy Two-Term (PI/PD Controllers Using Algebraic Product Inference

    Directory of Open Access Journals (Sweden)

    Murali Bosukonda

    2011-01-01

    Full Text Available This paper reveals mathematical models of the simplest Mamdani PI/PD controllers which employ two fuzzy sets (N: negative and P: positive on the universe of discourse (UoD of each of two input variables (displacement and velocity and three fuzzy sets (N: negative, Z: zero, and P: positive on the UoD of output variable (control output in the case of PD, and incremental control output in the case of PI. The basic constituents of these models are algebraic product/minimum AND, bounded sum/algebraic sum/maximum OR, algebraic product inference, three linear fuzzy control rules, and Center of Sums (CoS defuzzification. Properties of all these models are investigated. It is shown that all these controllers are different nonlinear PI/PD controllers with their proportional and derivative gains changing with the inputs. The proposed models are significant and useful to control community as they are completely new and qualitatively different from those reported in the literature.

  5. Comparison of the PIC model and the Lie algebraic metnod in the simulation of intense continuous beam transport

    Institute of Scientific and Technical Information of China (English)

    ZHAO xiao-Song; L(U) Jian-Qin

    2009-01-01

    Both the PIC(Particle-In-Cell) model and the Lie algebraic method can be used to simulate the transport of intense continuous beams.The PIC model is to calculate the space charge field,which is blended into the external field,and then simulate the trajectories of particles in the total field;the Lie algebraic method is to simulate the intense continuous beam transport with transport matrixes.Two simulation codes based on the two methods are developed respectively,and the simulated results of transport in a set of electrostatic lenses are compared.It is found that the results from the two codes are in agreement with each other.and both approaches have their own merits.

  6. Surfaces immersed in su(N+1) Lie algebras obtained from the CP{sup N} sigma models

    Energy Technology Data Exchange (ETDEWEB)

    Grundland, A M [Centre de Recherches Mathematiques, Universite de Montreal, CP 6128, Succ. Centre-ville, Montreal (Ciheam) H3C 3J7 (Canada) Universite du Quebec, Trois-Rivieres CP500 (QC) G9A 5H7 (Canada); Strasburger, A [Department of Mathematical Economics, Warsaw Agricultural University, ul. Nowoursynowska 166, 02-787 Warsaw (Poland); Zakrzewski, W J [Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom)

    2006-07-21

    We study some geometrical aspects of two-dimensional orientable surfaces arising from the study of CP{sup N} sigma models. To this aim we employ an identification of R{sup N(N+2)} with the Lie algebra su(N+1) by means of which we construct a generalized Weierstrass formula for immersion of such surfaces. The structural elements of the surface like its moving frame, the Gauss-Weingarten and the Gauss-Codazzi-Ricci equations are expressed in terms of the solution of the CP{sup N} model defining it. Further, the first and second fundamental forms, the Gaussian curvature, the mean curvature vector, the Willmore functional and the topological charge of surfaces are expressed in terms of this solution. We present detailed implementation of these results for surfaces immersed in su(2) and su(3) Lie algebras.

  7. BCS Ground State and XXZ Antiferromagnetic Model as SU(2),SU(1,1) Coherent States:AN Algebraic Diagonalization Method

    Institute of Scientific and Technical Information of China (English)

    XIEBing_Hao; ZHANGHong-Biao; 等

    2002-01-01

    An algebraic diagonalization method is proposed.As two examples,the Hamiltonians of BCS ground state under mean-field approximation and XXZ antiferromagnetic model in linear spin-wave frame have been diagonalized by using SU(2),SU(1,1) Lie algebraic method,respectively.Meanwhile,the eignenstates of the above two models are revealed to be SU(2),SU(1,1) coherent states,respectively,The relation between the usual Bogoliubov-Valatin transformation and the algebraic method in a special case is also discussed.

  8. $\\eta_{c}$ Elastic and Transition Form Factors: Contact Interaction and Algebraic Model

    CERN Document Server

    Bedolla, Marco A; Cobos-Martínez, J J; Bashir, Adnan

    2016-01-01

    For the flavor-singlet heavy quark system of charmonia in the pseudoscalar ($\\eta_c(1S)$) channel, we calculate the elastic (EFF) and transition form factors (TFF) ($\\eta_c(1S) \\rightarrow \\gamma \\gamma^*$) for a wide range of photon momentum transfer squared ($Q^2$). The framework for this analysis is provided by a symmetry-preserving Schwinger-Dyson equation (SDE) and Bethe-Salpeter equation (BSE) treatment of a vector$\\times$vector contact interaction (CI). We also employ an algebraic model (AM), developed earlier to describe the light quark systems. It correctly correlates infrared and ultraviolet dynamics of quantum chromodynamics (QCD). The CI results agree with the lattice data for low $Q^2$. For $Q^2 \\geqslant Q_0^2$, the results start deviating from the lattice results by more than $20 \\%$. $Q_0^2 \\thickapprox 2.5 {\\rm GeV}^2$ for the EFF and $\\thickapprox 25 {\\rm GeV}^2$ for the TFF. We also present the results for the EFF, TFF as well as $\\eta_c(1S)$ parton distribution amplitude for the AM. Wherev...

  9. An Algorithmic Structuration of a Type System for an Orthogonal Object/Relational Model

    CERN Document Server

    Benabbou, Amel; Amghar, Youssef

    2010-01-01

    Date and Darwen have proposed a theory of types, the latter forms the basis of a detailed presentation of a panoply of simple and complex types. However, this proposal has not been structured in a formal system. Specifically, Date and Darwen haven't indicated the formalism of the type system that corresponds to the type theory established. In this paper, we propose a pseudo-algorithmic and grammatical description of a system of types for Date and Darwen's model. Our type system is supposed take into account null values; for such intention, we introduce a particular type noted #, which expresses one or more occurrences of incomplete information in a database. Our algebraic grammar describes in detail the complete specification of an inheritance model and the subryping relation induced, thus the different definitions of related concepts.

  10. The Key Solution Algorithm of Linear Programming Model

    OpenAIRE

    Liu Jun; Zhao Chuan Cheng; Ren Zhi Guo; Feng Zhong Yi; Zhu Zheng Ping

    2016-01-01

    Linear programming problem is a common problem, and to solve the linear model is more plagued. The paper generating algorithm is based on mathematical theory and composition. The design of feasible solution algorithm illustrates key linear programming model, then we can find a better way to solve the linear programming model solutions.

  11. Algebraic multigrid preconditioning within parallel finite-element solvers for 3-D electromagnetic modelling problems in geophysics

    OpenAIRE

    Koldan, Jelena; Puzyrev, Vladimir; de la Puente, Josep; Houzeaux, Guillaume; José M. Cela

    2014-01-01

    We present an elaborate preconditioning scheme for Krylov subspace methods which has been developed to improve the performance and reduce the execution time of parallel node-based finite-element solvers for three-dimensional electromagnetic numerical modelling in exploration geophysics. This new preconditioner is based on algebraic multigrid that uses different basic relaxation methods, such as Jacobi, symmetric successive over-relaxation and Gauss-Seidel, as smoothers and the wav...

  12. Enveloping algebras

    International Nuclear Information System (INIS)

    Since the works of Gelfand, Harish-Chandra, Kostant and Duflo, a new theory has earned its place in the field of mathematics, due to the abundance of its results and the coherence of its methods: the theory of enveloping algebras. This study is the first to present the whole subject in textbook form. The most recent results are included, as well as complete proofs, starting from the elementary theory of Lie algebras. (Auth.)

  13. Characteristic Algebras of Fully Discrete Hyperbolic Type Equations

    OpenAIRE

    Habibullin, Ismagil T.

    2005-01-01

    The notion of the characteristic Lie algebra of the discrete hyperbolic type equation is introduced. An effective algorithm to compute the algebra for the equation given is suggested. Examples and further applications are discussed.

  14. Face Recognition Algorithm Based on Doubly Truncated Gaussian Mixture Model Using Hierarchical Clustering Algorithm

    OpenAIRE

    D. Haritha; K. Srinivasa Rao; Ch.Satyanarayana

    2012-01-01

    A robust and efficient face recognition system was developed and evaluated. The each individual face is characterized by 2D-DCT coefficients which follows a finite mixture of doubly truncated Gaussian distribution. In modelling the features vector of the face the number of components (in the mixture model) are determined by hierarchical clustering. The model parameters are estimated using EM algorithm. The face recognition algorithm is developed by maximum likelihood under Baysian frame. The ...

  15. Introduction to Clifford's Geometric Algebra

    OpenAIRE

    Hitzer, Eckhard

    2013-01-01

    Geometric algebra was initiated by W.K. Clifford over 130 years ago. It unifies all branches of physics, and has found rich applications in robotics, signal processing, ray tracing, virtual reality, computer vision, vector field processing, tracking, geographic information systems and neural computing. This tutorial explains the basics of geometric algebra, with concrete examples of the plane, of 3D space, of spacetime, and the popular conformal model. Geometric algebras are ideal to represen...

  16. A new model for algebraic Rossby solitary waves in rotation fluid and its solution

    Science.gov (United States)

    Chen, Yao-Deng; Yang, Hong-Wei; Gao, Yu-Fang; Yin, Bao-Shu; Feng, Xing-Ru

    2015-09-01

    A generalized Boussinesq equation that includes the dissipation effect is derived to describe a kind of algebraic Rossby solitary waves in a rotating fluid by employing perturbation expansions and stretching transformations of time and space. Using this equation, the conservation laws of algebraic Rossby solitary waves are discussed. It is found that the mass, the momentum, the energy, and the velocity of center of gravity of the algebraic solitary waves are conserved in the propagation process. Finally, the analytical solution of the equation is generated. Based on the analytical solution, the properties of the algebraic solitary waves and the dissipation effect are discussed. The results point out that, similar to classic solitary waves, the dissipation can cause the amplitude and the speed of solitary waves to decrease; however, unlike classic solitary waves, the algebraic solitary waves can split during propagation and the decrease of the detuning parameter can accelerate the occurrence of the solitary waves fission phenomenon. Project supported by the Shandong Provincial Key Laboratory of Marine Ecology and Environment and Disaster Prevention and Mitigation Project, China (Grant No. 2012010), the National Natural Science Foundation of China (Grant Nos. 41205082 and 41476019), the Special Funds for Theoretical Physics of the National Natural Science Foundation of China (Grant No. 11447205), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), China.

  17. Fast algorithms for transport models. Final report

    International Nuclear Information System (INIS)

    This project has developed a multigrid in space algorithm for the solution of the SN equations with isotropic scattering in slab geometry. The algorithm was developed for the Modified Linear Discontinuous (MLD) discretization in space which is accurate in the thick diffusion limit. It uses a red/black two-cell μ-line relaxation. This relaxation solves for all angles on two adjacent spatial cells simultaneously. It takes advantage of the rank-one property of the coupling between angles and can perform this inversion in O(N) operations. A version of the multigrid in space algorithm was programmed on the Thinking Machines Inc. CM-200 located at LANL. It was discovered that on the CM-200 a block Jacobi type iteration was more efficient than the block red/black iteration. Given sufficient processors all two-cell block inversions can be carried out simultaneously with a small number of parallel steps. The bottleneck is the need for sums of N values, where N is the number of discrete angles, each from a different processor. These are carried out by machine intrinsic functions and are well optimized. The overall algorithm has computational complexity O(log(M)), where M is the number of spatial cells. The algorithm is very efficient and represents the state-of-the-art for isotropic problems in slab geometry. For anisotropic scattering in slab geometry, a multilevel in angle algorithm was developed. A parallel version of the multilevel in angle algorithm has also been developed. Upon first glance, the shifted transport sweep has limited parallelism. Once the right-hand-side has been computed, the sweep is completely parallel in angle, becoming N uncoupled initial value ODE's. The author has developed a cyclic reduction algorithm that renders it parallel with complexity O(log(M)). The multilevel in angle algorithm visits log(N) levels, where shifted transport sweeps are performed. The overall complexity is O(log(N)log(M))

  18. Which multiplier algebras are $W^*$-algebras?

    OpenAIRE

    Akemann, Charles A.; Amini, Massoud; Asadi, Mohammad B.

    2013-01-01

    We consider the question of when the multiplier algebra $M(\\mathcal{A})$ of a $C^*$-algebra $\\mathcal{A}$ is a $ W^*$-algebra, and show that it holds for a stable $C^*$-algebra exactly when it is a $C^*$-algebra of compact operators. This implies that if for every Hilbert $C^*$-module $E$ over a $C^*$-algebra $\\mathcal{A}$, the algebra $B(E)$ of adjointable operators on $E$ is a $ W^*$-algebra, then $\\mathcal{A}$ is a $C^*$-algebra of compact operators. Also we show that a unital $C^*$-algebr...

  19. Mathematical Modeling and Algebraic Technique for Resolving a Single-Producer Multi-Retailer Integrated Inventory System with Scrap

    Directory of Open Access Journals (Sweden)

    Yuan-Shyi Peter Chiu

    2013-02-01

    Full Text Available This study uses mathematical modeling along with an algebraic technique to resolve the production-distribution policy for a single-producer multi-retailer integrated inventory system with scrap in production. We assume that a product is manufactured through an imperfect production process where all nonconforming items will be picked up and scrapped in each production cycle. After the entire lot is quality assured, multiple shipments will be delivered synchronously to m different retailers in each cycle. The objective is to determine the optimal replenishment lot size and optimal number of shipments that minimizes total expected costs for such a specific supply chains system. Conventional method is by the use of differential calculus on system cost function to derive the optimal policy (Chiu et al al., 2012c, whereas the proposed algebraic approach is a straightforward method that enables practitioners who may not have sufficient knowledge of calculus to understand and manage more effectively the real-life systems.

  20. Algebraic entropy for algebraic maps

    International Nuclear Information System (INIS)

    We propose an extension of the concept of algebraic entropy, as introduced by Bellon and Viallet for rational maps, to algebraic maps (or correspondences) of a certain kind. The corresponding entropy is an index of the complexity of the map. The definition inherits the basic properties from the definition of entropy for rational maps. We give an example with positive entropy, as well as two examples taken from the theory of Bäcklund transformations. (letter)

  1. Homotopy DG algebras induce homotopy BV algebras

    OpenAIRE

    Terilla, John; Tradler, Thomas; Wilson, Scott O.

    2011-01-01

    Let TA denote the space underlying the tensor algebra of a vector space A. In this short note, we show that if A is a differential graded algebra, then TA is a differential Batalin-Vilkovisky algebra. Moreover, if A is an A-infinity algebra, then TA is a commutative BV-infinity algebra.

  2. RSA算法中Z*(φ)(n)的代数结构研究%Study on Algebraic Structure of Z*(φ)(n) in RSA Algorithm

    Institute of Scientific and Technical Information of China (English)

    裴东林; 胡建军; 李旭

    2013-01-01

    [Abstract] Based on the theory of quadratic residues, this paper considers the algebraic structure of Z*φ(n) in the two order strong RSA algorithm. It is proved that the element α of Z*φ(n) gets maximal order if and only if gcd(α±l,n1) = 1, and the numbers of quadratic residues in the group Z*φ(n) is φ(φ(n))/8 .Z*φ(n) is divided up by the group which is composed of all quadratic residues, and all cosets form a Klein eight-group. It proves that the group Z*φ(n) can be generated by seven elements of quadratic non-residues.%应用二次剩余理论,对二阶强RSA算法中Z*(φ)(n)的代数结构进行研究,证明Z*(φ)(n)中元素a取最大阶的充要条件为gcd(a±1,n1)=1,以及任意元素的阶Z*(φ)(n)中模(φ)(n)的二次剩余个数为(φ)(φ)(n))/8,以所有二次剩余构成的群对Z*(φ)(n)进行分割,利用所有陪集构成一个Klein八元群,在此基础上证明Z*(φ)(n)可由7个二次非剩余元素生成.

  3. Enlarged symmetry algebras of spin chains, loop models, and S-matrices

    OpenAIRE

    Read, N.; Saleur, H.

    2007-01-01

    The symmetry algebras of certain families of quantum spin chains are considered in detail. The simplest examples possess m states per site (m\\geq2), with nearest-neighbor interactions with U(m) symmetry, under which the sites transform alternately along the chain in the fundamental m and its conjugate representation \\bar{m}. We find that these spin chains, even with {\\em arbitrary} coefficients of these interactions, have a symmetry algebra A_m much larger than U(m), which implies that the en...

  4. A Comparison of Explicit Algebraic Turbulence Models and the Energy-Flux Budget (EFB) Closure in Gabls

    Science.gov (United States)

    Lazeroms, W. M.; Bazile, E.; Brethouwer, G.; Wallin, S.; Johansson, A. V.; Svensson, G.

    2014-12-01

    Turbulent flows with buoyancy effects occur in many situations, both in industry and in the atmosphere. It is challenging to correctly model such flows, especially in the case of stably stratified turbulence, where vertical motions are damped by buoyancy forces. For this purpose, we have derived a so-called explicit algebraic model for the Reynolds stresses and turbulent heat flux that gives accurate predictions in flows with buoyancy effects. Although inspired by turbulence models from engineering, the main aim of our work is to improve the parametrization of turbulence in the atmospheric boundary layer (ABL). Explicit algebraic turbulence models are a class of parametrizations that, on the one hand, are more advanced than standard eddy-diffusivity relations. On the other hand, they are signficantly easier to handle numerically than models that require the solution of the full flux-budget equations. To derive the algebraic model, we apply the assumption that transport terms of dimensionless fluxes can be neglected. Careful considerations of the algebra lead to a consistent formulation of the Reynolds stresses and turbulent heat flux, which is more general and robust than previous models of a similar kind. The model is shown to give good results compared to direct numerical simulations of engineering test cases, such as turbulent channel flow. Recent work has been aimed at testing the model in an atmospheric context. The first of these tests makes use of the GABLS1 case, in which a stable atmospheric boundary layer develops through a constant surface cooling rate. The model is able to give good predictions of this case compared to LES (see attached figure). Interestingly, the results are very close to the outcome of the recently developed Energy-Flux-Budget (EFB) closure by Zilitinkevich et al. (2013). A detailed discussion of the similarities and differences between these models will be given, which can give insight in the more general gap between engineering and

  5. Solving multi-customer FPR model with quality assurance and discontinuous deliveries using a two-phase algebraic approach.

    Science.gov (United States)

    Chiu, Yuan-Shyi Peter; Chou, Chung-Li; Chang, Huei-Hsin; Chiu, Singa Wang

    2016-01-01

    A multi-customer finite production rate (FPR) model with quality assurance and discontinuous delivery policy was investigated in a recent paper (Chiu et al. in J Appl Res Technol 12(1):5-13, 2014) using differential calculus approach. This study employs mathematical modeling along with a two-phase algebraic method to resolve such a specific multi-customer FPR model. As a result, the optimal replenishment lot size and number of shipments can be derived without using the differential calculus. Such a straightforward method may assist practitioners who with insufficient knowledge of calculus in learning and managing the real multi-customer FPR systems more effectively. PMID:27186457

  6. Hybrid learning algorithm integrating genetic algorithms with neural networks for saccade generation model; Saccade gankyu undo model ni okeru identeki algorithm to kobaiho no togogata gakushu algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Arai, K. [Mitsubishi Chemical Corp., Tokyo (Japan); Aiyoshi, E. [Keio University, Tokyo (Japan)

    1997-01-20

    Saccade eve movements are among the most rapid vet precise of all movements produced by higher mammals. Recently we have proposed a spatio-temporal neural network model of the superior colliculus which uses lateral excitatory and inhibitory interconnections to help control both the dynamic and static behavior of saccadic eve movements. In this paper a new learning algorithm integrating genetic algorithms with neural networks for the lateral inhibitory and excitatory interconnections in the saccade generation model is presented. Data base for the training were obtained from neurophysiological experiments, and the training converged well even if random connections were chosen as initial conditions. The resulting network model succeeded in making accurate saccadic eve movements of a variety of sizes while producing realistic spatio-temporal patterns of collicular discharge. 18 refs., 8 figs., 1 tab.

  7. Algebras, dialgebras, and polynomial identities

    CERN Document Server

    Bremner, Murray R

    2012-01-01

    This is a survey of some recent developments in the theory of associative and nonassociative dialgebras, with an emphasis on polynomial identities and multilinear operations. We discuss associative, Lie, Jordan, and alternative algebras, and the corresponding dialgebras; the KP algorithm for converting identities for algebras into identities for dialgebras; the BSO algorithm for converting operations in algebras into operations in dialgebras; Lie and Jordan triple systems, and the corresponding disystems; and a noncommutative version of Lie triple systems based on the trilinear operation abc-bca. The paper concludes with a conjecture relating the KP and BSO algorithms, and some suggestions for further research. Most of the original results are joint work with Raul Felipe, Luiz A. Peresi, and Juana Sanchez-Ortega.

  8. The Lipkin Model in the su(M+1)-Algebra for Many-Fermion System and its Counterpart in the Schwinger Boson Representation

    CERN Document Server

    Providência, C; Tsue, Y; Yamamura, M

    2005-01-01

    Following the Schwinger boson representation for the su(M+1)- and the su(N,1)-algebra presented by two of the present authors (J. da P. and M. Y.) and Kuriyama, a possible counterpart of the Lipkin model in the su(M+1)-algebra formulated in the fermion space is presented. The free vacuum, which plays a fundamental role in the conventional treatment of the Lipkin model, is generalized in a quite natural way, and further, the excited state generating operators such as the particle-hole pairs are also given in a natural scheme. As concrete examples, the cases of the su(2)-, su(3)- and the su(4)-algebra are discussed. Especially, the case of the su(4)-algebra is investigated in detail in relation to the nucleon pairing correlations and the high temperature superconductivity.

  9. Piecewise algebraic varieties

    Institute of Scientific and Technical Information of China (English)

    WANG Renhong; ZHU Chungang

    2004-01-01

    The piecewise algebraic variety is a generalization of the classical algebraic variety. This paper discusses some properties of piecewise algebraic varieties and their coordinate rings based on the knowledge of algebraic geometry.

  10. Flipping an Algebra Classroom: Analyzing, Modeling, and Solving Systems of Linear Equations

    Science.gov (United States)

    Kirvan, Rebecca; Rakes, Christopher R.; Zamora, Regie

    2015-01-01

    The present study investigated whether flipping an algebra classroom led to a stronger focus on conceptual understanding and improved learning of systems of linear equations for 54 seventh- and eighth-grade students using teacher journal data and district-mandated unit exam items. Multivariate analysis of covariance was used to compare scores on…

  11. Prospective Mathematics Teachers' Sense Making of Polynomial Multiplication and Factorization Modeled with Algebra Tiles

    Science.gov (United States)

    Caglayan, Günhan

    2013-01-01

    This study is about prospective secondary mathematics teachers' understanding and sense making of representational quantities generated by algebra tiles, the quantitative units (linear vs. areal) inherent in the nature of these quantities, and the quantitative addition and multiplication operations--referent preserving versus referent…

  12. Algebraic modelling and performance evaluation of acyclic fork-join queueing networks

    OpenAIRE

    Krivulin, Nikolai K.

    2012-01-01

    Simple lower and upper bounds on mean cycle time in stochastic acyclic fork-join queueing networks are derived using a (max,+)-algebra based representation of network dynamics. The behaviour of the bounds under various assumptions concerning the service times in the networks is discussed, and related numerical examples are presented.

  13. Constructing a Coherent Problem Model to Facilitate Algebra Problem Solving in a Chemistry Context

    Science.gov (United States)

    Ngu, Bing Hiong; Yeung, Alexander Seeshing; Phan, Huy P.

    2015-01-01

    An experiment using a sample of 11th graders compared text editing and worked examples approaches in learning to solve dilution and molarity algebra word problems in a chemistry context. Text editing requires students to assess the structure of a word problem by specifying whether the problem text contains sufficient, missing, or irrelevant…

  14. Algebraic Bethe Ansatz for Open XXX Model with Triangular Boundary Matrices

    Science.gov (United States)

    Belliard, Samuel; Crampé, Nicolas; Ragoucy, Eric

    2013-05-01

    We consider an open XXX spin chain with two general boundary matrices whose entries obey a relation, which is equivalent to the possibility to put simultaneously the two matrices in a upper-triangular form. We construct Bethe vectors by means of a generalized algebraic Bethe ansatz. As usual, the method uses Bethe equations and provides transfer matrix eigenvalues.

  15. Proposing and Testing a Model to Explain Traits of Algebra Preparedness

    Science.gov (United States)

    Venenciano, Linda; Heck, Ronald

    2016-01-01

    Early experiences with theoretical thinking and generalization in measurement are hypothesized to develop constructs we name here as logical reasoning and preparedness for algebra. Based on work of V. V. Davydov (1975), the Measure Up (MU) elementary grades experimental mathematics curriculum uses quantities of area, length, volume, and mass to…

  16. Linear algebra

    CERN Document Server

    Liesen, Jörg

    2015-01-01

    This self-contained textbook takes a matrix-oriented approach to linear algebra and presents a complete theory, including all details and proofs, culminating in the Jordan canonical form and its proof. Throughout the development, the applicability of the results is highlighted. Additionally, the book presents special topics from applied linear algebra including matrix functions, the singular value decomposition, the Kronecker product and linear matrix equations. The matrix-oriented approach to linear algebra leads to a better intuition and a deeper understanding of the abstract concepts, and therefore simplifies their use in real world applications. Some of these applications are presented in detailed examples. In several ‘MATLAB-Minutes’ students can comprehend the concepts and results using computational experiments. Necessary basics for the use of MATLAB are presented in a short introduction. Students can also actively work with the material and practice their mathematical skills in more than 300 exerc...

  17. Clifford algebra, geometric algebra, and applications

    OpenAIRE

    Lundholm, Douglas; Svensson, Lars

    2009-01-01

    These are lecture notes for a course on the theory of Clifford algebras, with special emphasis on their wide range of applications in mathematics and physics. Clifford algebra is introduced both through a conventional tensor algebra construction (then called geometric algebra) with geometric applications in mind, as well as in an algebraically more general form which is well suited for combinatorics, and for defining and understanding the numerous products and operations of the algebra. The v...

  18. Cofree Hopf algebras on Hopf bimodule algebras

    OpenAIRE

    Fang, Xin; Jian, Run-Qiang

    2013-01-01

    We investigate a Hopf algebra structure on the cotensor coalgebra associated to a Hopf bimodule algebra which contains universal version of Clifford algebras and quantum groups as examples. It is shown to be the bosonization of the quantum quasi-shuffle algebra built on the space of its right coinvariants. The universal property and a Rota-Baxter algebra structure are established on this new algebra.

  19. A numerical study of scalar dispersion downstream of a wall-mounted cube using direct simulations and algebraic flux models

    International Nuclear Information System (INIS)

    Research highlights: → The computed DNS statistics indicate that a gradient-transport scheme can be applied to the vertical and spanwise scalar flux components. → The streamwise scalar flux is characterized by a counter-gradient transport mechanism in the wake region close to the obstacle. → The wake profiles of scalar fluctuations and the shape of probability density functions do not suggest a significant flapping movement of the scalar plume. → The evaluation of scalar dispersion models must include a careful assessment of the computed mean velocity field and Reynolds stress tensor. → Algebraic models provide an improved prediction of the mean concentration field as compared to the standard eddy-diffusivity model. -- Abstract: The dispersion of a passive scalar downstream of a wall-mounted cube is examined using direct numerical simulations and turbulence models applied to the Reynolds equations. The scalar is released from a circular source located on top of the obstacle, which is immersed in a developing boundary-layer flow. Direct simulations are performed to give insight into the mixing process and to provide a reference database for turbulence closures. Algebraic flux models are evaluated against the standard eddy-diffusivity representation. Coherent structures periodically released from the cube top are responsible for a counter-diffusion mechanism appearing in the streamwise scalar flux. Alternating vortex pairs form from the lateral edges of the cube, but the intensity profiles and probability density functions of scalar fluctuations suggest that they do not cause a significant flapping movement of the scalar plume. The gradient-transport scheme is consistent with the vertical and spanwise scalar flux components. From the comparative study with our direct simulations, we further stress that Reynolds stress predictions must be carefully evaluated along with scalar flux closures in order to establish the reliability of Reynolds

  20. A numerical study of scalar dispersion downstream of a wall-mounted cube using direct simulations and algebraic flux models

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, R., E-mail: riccardo.rossi12@unibo.i [Laboratorio di Termofluidodinamica Computazionale Seconda Facolta di Ingegneria di Forli, Universita di Bologna Via Fontanelle 40, 47100 Forli (Italy); Center for Turbulence Research Department of Mechanical Engineering Stanford University, CA 94305 (United States); Philips, D.A.; Iaccarino, G. [Center for Turbulence Research Department of Mechanical Engineering Stanford University, CA 94305 (United States)

    2010-10-15

    Research highlights: {yields} The computed DNS statistics indicate that a gradient-transport scheme can be applied to the vertical and spanwise scalar flux components. {yields} The streamwise scalar flux is characterized by a counter-gradient transport mechanism in the wake region close to the obstacle. {yields} The wake profiles of scalar fluctuations and the shape of probability density functions do not suggest a significant flapping movement of the scalar plume. {yields} The evaluation of scalar dispersion models must include a careful assessment of the computed mean velocity field and Reynolds stress tensor. {yields} Algebraic models provide an improved prediction of the mean concentration field as compared to the standard eddy-diffusivity model. -- Abstract: The dispersion of a passive scalar downstream of a wall-mounted cube is examined using direct numerical simulations and turbulence models applied to the Reynolds equations. The scalar is released from a circular source located on top of the obstacle, which is immersed in a developing boundary-layer flow. Direct simulations are performed to give insight into the mixing process and to provide a reference database for turbulence closures. Algebraic flux models are evaluated against the standard eddy-diffusivity representation. Coherent structures periodically released from the cube top are responsible for a counter-diffusion mechanism appearing in the streamwise scalar flux. Alternating vortex pairs form from the lateral edges of the cube, but the intensity profiles and probability density functions of scalar fluctuations suggest that they do not cause a significant flapping movement of the scalar plume. The gradient-transport scheme is consistent with the vertical and spanwise scalar flux components. From the comparative study with our direct simulations, we further stress that Reynolds stress predictions must be carefully evaluated along with scalar flux closures in order to establish the reliability of

  1. On uniform topological algebras

    OpenAIRE

    Azhari, M. El

    2013-01-01

    The uniform norm on a uniform normed Q-algebra is the only uniform Q-algebra norm on it. The uniform norm on a regular uniform normed Q-algebra with unit is the only uniform norm on it. Let A be a uniform topological algebra whose spectrum M (A) is equicontinuous, then A is a uniform normed algebra. Let A be a regular semisimple commutative Banach algebra, then every algebra norm on A is a Q-algebra norm on A.

  2. Generalized exterior algebras

    OpenAIRE

    Marchuk, Nikolay

    2011-01-01

    Exterior algebras and differential forms are widely used in many fields of modern mathematics and theoretical physics. In this paper we define a notion of $N$-metric exterior algebra, which depends on $N$ matrices of structure constants. The usual exterior algebra (Grassmann algebra) can be considered as 0-metric exterior algebra. Clifford algebra can be considered as 1-metric exterior algebra. $N$-metric exterior algebras for $N\\geq2$ can be considered as generalizations of the Grassmann alg...

  3. Word Hopf algebras

    OpenAIRE

    Hazewinkel, Michiel

    2004-01-01

    Two important generalizations of the Hopf algebra of symmetric functions are the Hopf algebra of noncommutative symmetric functions and its graded dual the Hopf algebra of quasisymmetric functions. A common generalization of the latter is the selfdual Hopf algebra of permutations (MPR Hopf algebra). This latter Hopf algebra can be seen as a Hopf algebra of endomorphisms of a Hopf algebra. That turns out to be a fruitful way of looking at things and gives rise to wide ranging further generaliz...

  4. Linear algebra

    CERN Document Server

    Allenby, Reg

    1995-01-01

    As the basis of equations (and therefore problem-solving), linear algebra is the most widely taught sub-division of pure mathematics. Dr Allenby has used his experience of teaching linear algebra to write a lively book on the subject that includes historical information about the founders of the subject as well as giving a basic introduction to the mathematics undergraduate. The whole text has been written in a connected way with ideas introduced as they occur naturally. As with the other books in the series, there are many worked examples.Solutions to the exercises are available onlin

  5. Lie algebras

    CERN Document Server

    Jacobson, Nathan

    1979-01-01

    Lie group theory, developed by M. Sophus Lie in the 19th century, ranks among the more important developments in modern mathematics. Lie algebras comprise a significant part of Lie group theory and are being actively studied today. This book, by Professor Nathan Jacobson of Yale, is the definitive treatment of the subject and can be used as a textbook for graduate courses.Chapter I introduces basic concepts that are necessary for an understanding of structure theory, while the following three chapters present the theory itself: solvable and nilpotent Lie algebras, Carlan's criterion and its

  6. Linear algebra

    CERN Document Server

    Stoll, R R

    1968-01-01

    Linear Algebra is intended to be used as a text for a one-semester course in linear algebra at the undergraduate level. The treatment of the subject will be both useful to students of mathematics and those interested primarily in applications of the theory. The major prerequisite for mastering the material is the readiness of the student to reason abstractly. Specifically, this calls for an understanding of the fact that axioms are assumptions and that theorems are logical consequences of one or more axioms. Familiarity with calculus and linear differential equations is required for understand

  7. A Deductive Approach towards Reasoning about Algebraic Transition Systems

    OpenAIRE

    Jun Fu; Jinzhao Wu; Hongyan Tan

    2015-01-01

    Algebraic transition systems are extended from labeled transition systems by allowing transitions labeled by algebraic equations for modeling more complex systems in detail. We present a deductive approach for specifying and verifying algebraic transition systems. We modify the standard dynamic logic by introducing algebraic equations into modalities. Algebraic transition systems are embedded in modalities of logic formulas which specify properties of algebraic transition systems. The semanti...

  8. Sparse Representations of Clifford and Tensor algebras in Maxima

    OpenAIRE

    Prodanov, Dimiter; Toth, Viktor T.

    2016-01-01

    Clifford algebras have broad applications in science and engineering. The use of Clifford algebras can be further promoted in these fields by availability of computational tools that automate tedious routine calculations. We offer an extensive demonstration of the applications of Clifford algebras in electromagnetism using the geometric algebra G3 = Cl(3,0) as a computational model in the Maxima computer algebra system. We compare the geometric algebra-based approach with conventional symboli...

  9. Grapham: Graphical Models with Adaptive Random Walk Metropolis Algorithms

    OpenAIRE

    Vihola, Matti

    2008-01-01

    Recently developed adaptive Markov chain Monte Carlo (MCMC) methods have been applied successfully to many problems in Bayesian statistics. Grapham is a new open source implementation covering several such methods, with emphasis on graphical models for directed acyclic graphs. The implemented algorithms include the seminal Adaptive Metropolis algorithm adjusting the proposal covariance according to the history of the chain and a Metropolis algorithm adjusting the proposal scale based on the o...

  10. GOLDMAN ALGEBRA, OPERS AND THE SWAPPING ALGEBRA

    OpenAIRE

    Labourie, François

    2012-01-01

    We define a Poisson Algebra called the {\\em swapping algebra} using the intersection of curves in the disk. We interpret a subalgebra of the fraction algebra of the swapping algebra -- called the {\\em algebra of multifractions} -- as an algebra of functions on the space of cross ratios and thus as an algebra of functions on the Hitchin component as well as on the space of $\\mathsf{SL}_n(\\mathbb R)$-opers with trivial holonomy. We relate this Poisson algebra to the Atiyah--Bott--Goldman symple...

  11. Algebraic Squares: Complete and Incomplete.

    Science.gov (United States)

    Gardella, Francis J.

    2000-01-01

    Illustrates ways of using algebra tiles to give students a visual model of competing squares that appear in algebra as well as in higher mathematics. Such visual representations give substance to the symbolic manipulation and give students who do not learn symbolically a way of understanding the underlying concepts of completing the square. (KHR)

  12. Algebraic Thinking in Adult Education

    Science.gov (United States)

    Manly, Myrna; Ginsburg, Lynda

    2010-01-01

    In adult education, algebraic thinking can be a sense-making tool that introduces coherence among mathematical concepts for those who previously have had trouble learning math. Further, a modeling approach to algebra connects mathematics and the real world, demonstrating the usefulness of math to those who have seen it as just an academic…

  13. Smarandache Jordan Algebras - abstract

    OpenAIRE

    Vasantha Kandasamy, W. B.; Christopher, S.; A. Victor Devadoss

    2004-01-01

    We prove a S-commutative Jordan Algebra is a S-weakly commutative Jordan algebra. We define a S-Jordan algebra to be S-simple Jordan algebras if the S-Jordan algebra has no S-Jordan ideals. We obtain several other interesting notions and results on S-Jordan algebras.

  14. DEVELOPMENT OF 2D HUMAN BODY MODELING USING THINNING ALGORITHM

    Directory of Open Access Journals (Sweden)

    K. Srinivasan

    2010-11-01

    Full Text Available Monitoring the behavior and activities of people in Video surveillance has gained more applications in Computer vision. This paper proposes a new approach to model the human body in 2D view for the activity analysis using Thinning algorithm. The first step of this work is Background subtraction which is achieved by the frame differencing algorithm. Thinning algorithm has been used to find the skeleton of the human body. After thinning, the thirteen feature points like terminating points, intersecting points, shoulder, elbow, and knee points have been extracted. Here, this research work attempts to represent the body model in three different ways such as Stick figure model, Patch model and Rectangle body model. The activities of humans have been analyzed with the help of 2D model for the pre-defined poses from the monocular video data. Finally, the time consumption and efficiency of our proposed algorithm have been evaluated.

  15. Methodology and basic algorithms of the Livermore Economic Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    Bell, R.B.

    1981-03-17

    The methodology and the basic pricing algorithms used in the Livermore Economic Modeling System (EMS) are described. The report explains the derivations of the EMS equations in detail; however, it could also serve as a general introduction to the modeling system. A brief but comprehensive explanation of what EMS is and does, and how it does it is presented. The second part examines the basic pricing algorithms currently implemented in EMS. Each algorithm's function is analyzed and a detailed derivation of the actual mathematical expressions used to implement the algorithm is presented. EMS is an evolving modeling system; improvements in existing algorithms are constantly under development and new submodels are being introduced. A snapshot of the standard version of EMS is provided and areas currently under study and development are considered briefly.

  16. Algebraic Stacks

    Indian Academy of Sciences (India)

    Tomás L Gómez

    2001-02-01

    This is an expository article on the theory of algebraic stacks. After introducing the general theory, we concentrate in the example of the moduli stack of vector bundles, giving a detailed comparison with the moduli scheme obtained via geometric invariant theory.

  17. Algebraic Topology

    CERN Document Server

    Oliver, Bob; Pawałowski, Krzystof

    1991-01-01

    As part of the scientific activity in connection with the 70th birthday of the Adam Mickiewicz University in Poznan, an international conference on algebraic topology was held. In the resulting proceedings volume, the emphasis is on substantial survey papers, some presented at the conference, some written subsequently.

  18. Models and algorithms for biomolecules and molecular networks

    CERN Document Server

    DasGupta, Bhaskar

    2016-01-01

    By providing expositions to modeling principles, theories, computational solutions, and open problems, this reference presents a full scope on relevant biological phenomena, modeling frameworks, technical challenges, and algorithms. * Up-to-date developments of structures of biomolecules, systems biology, advanced models, and algorithms * Sampling techniques for estimating evolutionary rates and generating molecular structures * Accurate computation of probability landscape of stochastic networks, solving discrete chemical master equations * End-of-chapter exercises

  19. Sequential Markov coalescent algorithms for population models with demographic structure

    OpenAIRE

    A. Eriksson; Mahjani, B.; Mehlig, B.

    2009-01-01

    We analyse sequential Markov coalescent algorithms for populations with demographic structure: for a bottleneck model, a population-divergence model, and for a two-island model with migration. The sequential Markov coalescent method is an approximation to the coalescent suggested by McVean and Cardin, and Marjoram and Wall. Within this algorithm we compute, for two individuals randomly sampled from the population, the correlation between times to the most recent common ancestor and the linkag...

  20. Model-Free Adaptive Control Algorithm with Data Dropout Compensation

    Directory of Open Access Journals (Sweden)

    Xuhui Bu

    2012-01-01

    Full Text Available The convergence of model-free adaptive control (MFAC algorithm can be guaranteed when the system is subject to measurement data dropout. The system output convergent speed gets slower as dropout rate increases. This paper proposes a MFAC algorithm with data compensation. The missing data is first estimated using the dynamical linearization method, and then the estimated value is introduced to update control input. The convergence analysis of the proposed MFAC algorithm is given, and the effectiveness is also validated by simulations. It is shown that the proposed algorithm can compensate the effect of the data dropout, and the better output performance can be obtained.

  1. Algebraic Bethe ansätze and eigenvalue-based determinants for Dicke–Jaynes–Cummings–Gaudin quantum integrable models

    International Nuclear Information System (INIS)

    In this work, we construct an alternative formulation to the traditional algebraic Bethe ansätze for quantum integrable models derived from a generalized rational Gaudin algebra realized in terms of a collection of spins 1/2 coupled to a single bosonic mode. The ensemble of resulting models which we call Dicke–Jaynes–Cummings–Gaudin models are particularly relevant for the description of light–matter interaction in the context of quantum optics. Having two distinct ways to write any eigenstate of these models we then combine them in order to write overlaps and form factors of local operators in terms of partition functions with domain wall boundary conditions. We also demonstrate that they can all be written in terms of determinants of matrices whose entries only depend on the eigenvalues of the conserved charges. Since these eigenvalues obey a much simpler set of quadratic Bethe equations, the resulting expressions could then offer important simplifications for the numerical treatment of these models. (paper)

  2. A motion retargeting algorithm based on model simplification

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new motion retargeting algorithm is presented, which adapts the motion capture data to a new character. To make the resulting motion realistic, the physically-based optimization method is adopted. However, the optimization process is difficult to converge to the optimal value because of high complexity of the physical human model. In order to address this problem, an appropriate simplified model automatically determined by a motion analysis technique is utilized, and then motion retargeting with this simplified model as an intermediate agent is implemented. The entire motion retargeting algorithm involves three steps of nonlinearly constrained optimization: forward retargeting, motion scaling and inverse retargeting. Experimental results show the validity of this algorithm.

  3. Quantum Monte Carlo methods algorithms for lattice models

    CERN Document Server

    Gubernatis, James; Werner, Philipp

    2016-01-01

    Featuring detailed explanations of the major algorithms used in quantum Monte Carlo simulations, this is the first textbook of its kind to provide a pedagogical overview of the field and its applications. The book provides a comprehensive introduction to the Monte Carlo method, its use, and its foundations, and examines algorithms for the simulation of quantum many-body lattice problems at finite and zero temperature. These algorithms include continuous-time loop and cluster algorithms for quantum spins, determinant methods for simulating fermions, power methods for computing ground and excited states, and the variational Monte Carlo method. Also discussed are continuous-time algorithms for quantum impurity models and their use within dynamical mean-field theory, along with algorithms for analytically continuing imaginary-time quantum Monte Carlo data. The parallelization of Monte Carlo simulations is also addressed. This is an essential resource for graduate students, teachers, and researchers interested in ...

  4. Poincare duality and commutative differential graded algebras

    OpenAIRE

    Lambrechts, Pascal; Stanley, Don

    2007-01-01

    We prove that every commutative differential graded algebra whose cohomology is a simply-connected Poincare duality algebra is quasi-isomorphic to one whose underlying algebra is simply-connected and satisfies Poincare duality in the same dimension. This has application in particular to the study of CDGA models of configuration spaces on a closed manifold.

  5. An Algebraic Approach to the Scattering Equations

    OpenAIRE

    Huang, Rijun; Rao, Junjie; Feng, Bo; He, Yang-Hui

    2015-01-01

    We employ the so-called companion matrix method from computational algebraic geometry, tailored for zero-dimensional ideals, to study the scattering equations. The method renders the CHY-integrand of scattering amplitudes computable using simple linear algebra and is amenable to an algorithmic approach. Certain identities in the amplitudes as well as rationality of the final integrand become immediate in this formalism.

  6. Exact Symbolic-Numeric Computation of Planar Algebraic Curves

    OpenAIRE

    Berberich, Eric; Emeliyanenko, Pavel; Kobel, Alexander; Sagraloff, Michael

    2012-01-01

    We present a novel certified and complete algorithm to compute arrangements of real planar algebraic curves. It provides a geometric-topological analysis of the decomposition of the plane induced by a finite number of algebraic curves in terms of a cylindrical algebraic decomposition. From a high-level perspective, the overall method splits into two main subroutines, namely an algorithm denoted Bisolve to isolate the real solutions of a zero-dimensional bivariate system, and an algorithm deno...

  7. Spatial-Operator Algebra For Robotic Manipulators

    Science.gov (United States)

    Rodriguez, Guillermo; Kreutz, Kenneth K.; Milman, Mark H.

    1991-01-01

    Report discusses spatial-operator algebra developed in recent studies of mathematical modeling, control, and design of trajectories of robotic manipulators. Provides succinct representation of mathematically complicated interactions among multiple joints and links of manipulator, thereby relieving analyst of most of tedium of detailed algebraic manipulations. Presents analytical formulation of spatial-operator algebra, describes some specific applications, summarizes current research, and discusses implementation of spatial-operator algebra in the Ada programming language.

  8. An Automatic Registration Algorithm for 3D Maxillofacial Model

    Science.gov (United States)

    Qiu, Luwen; Zhou, Zhongwei; Guo, Jixiang; Lv, Jiancheng

    2016-09-01

    3D image registration aims at aligning two 3D data sets in a common coordinate system, which has been widely used in computer vision, pattern recognition and computer assisted surgery. One challenging problem in 3D registration is that point-wise correspondences between two point sets are often unknown apriori. In this work, we develop an automatic algorithm for 3D maxillofacial models registration including facial surface model and skull model. Our proposed registration algorithm can achieve a good alignment result between partial and whole maxillofacial model in spite of ambiguous matching, which has a potential application in the oral and maxillofacial reparative and reconstructive surgery. The proposed algorithm includes three steps: (1) 3D-SIFT features extraction and FPFH descriptors construction; (2) feature matching using SAC-IA; (3) coarse rigid alignment and refinement by ICP. Experiments on facial surfaces and mandible skull models demonstrate the efficiency and robustness of our algorithm.

  9. Testing algebraic geometric codes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Property testing was initially studied from various motivations in 1990’s. A code C  GF (r)n is locally testable if there is a randomized algorithm which can distinguish with high possibility the codewords from a vector essentially far from the code by only accessing a very small (typically constant) number of the vector’s coordinates. The problem of testing codes was firstly studied by Blum, Luby and Rubinfeld and closely related to probabilistically checkable proofs (PCPs). How to characterize locally testable codes is a complex and challenge problem. The local tests have been studied for Reed-Solomon (RS), Reed-Muller (RM), cyclic, dual of BCH and the trace subcode of algebraicgeometric codes. In this paper we give testers for algebraic geometric codes with linear parameters (as functions of dimensions). We also give a moderate condition under which the family of algebraic geometric codes cannot be locally testable.

  10. Helmholtz algebraic solitons

    International Nuclear Information System (INIS)

    We report, to the best of our knowledge, the first exact analytical algebraic solitons of a generalized cubic-quintic Helmholtz equation. This class of governing equation plays a key role in photonics modelling, allowing a full description of the propagation and interaction of broad scalar beams. New conservation laws are presented, and the recovery of paraxial results is discussed in detail. The stability properties of the new solitons are investigated by combining semi-analytical methods and computer simulations. In particular, new general stability regimes are reported for algebraic bright solitons.

  11. Helmholtz algebraic solitons

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J M; McDonald, G S [Joule Physics Laboratory, School of Computing, Science and Engineering, Materials and Physics Research Centre, University of Salford, Salford M5 4WT (United Kingdom); Chamorro-Posada, P, E-mail: j.christian@salford.ac.u [Departamento de Teoria de la Senal y Comunicaciones e Ingenieria Telematica, Universidad de Valladolid, ETSI Telecomunicacion, Campus Miguel Delibes s/n, 47011 Valladolid (Spain)

    2010-02-26

    We report, to the best of our knowledge, the first exact analytical algebraic solitons of a generalized cubic-quintic Helmholtz equation. This class of governing equation plays a key role in photonics modelling, allowing a full description of the propagation and interaction of broad scalar beams. New conservation laws are presented, and the recovery of paraxial results is discussed in detail. The stability properties of the new solitons are investigated by combining semi-analytical methods and computer simulations. In particular, new general stability regimes are reported for algebraic bright solitons.

  12. A differential algebraic approach for the modeling of polycrystalline ferromagnetic hysteresis with minor loops and frequency dependence

    Science.gov (United States)

    Wang, Dan; Wang, Linxiang; Melnik, Roderick

    2016-07-01

    In the current paper, a nonlinear differential algebraic approach is proposed for the modeling of hysteretic dynamics of polycrystalline ferromagnetic materials. The model is constructed by employing a phenomenological theory to the magnetization orientation switching. For the modeling of hysteresis in polycrystalline ferromagnetic materials, the single crystal model is applied to each magnetic domain along its own principal axis. The overall dynamics of the polycrystalline materials is obtained by taking a weighted combination of the dynamics of all magnetic domains. The weight function for the combination is taken as the distribution function of the principal axes. Numerical simulations are performed and comparisons with its experimental counterparts are presented. The hysteretic dynamics caused by orientation switching processes is accurately captured by the proposed model. Minor hysteresis loops associated with partial-amplitude loadings are also captured. Rate dependence of the hysteresis loops are inherently incorporated into the model due to its differential nature.

  13. A non-symmetric Yang–Baxter algebra for the quantum nonlinear Schrödinger model

    International Nuclear Information System (INIS)

    We study certain non-symmetric wavefunctions associated with the quantum nonlinear Schrödinger model, introduced by Komori and Hikami using Gutkin’s propagation operator, which involves representations of the degenerate affine Hecke algebra. We highlight how these functions can be generated using a vertex-type operator formalism similar to the recursion defining the symmetric (Bethe) wavefunction in the quantum inverse scattering method. Furthermore, some of the commutation relations encoded in the Yang–Baxter equation for the relevant monodromy matrix are generalized to the non-symmetric case. (paper)

  14. Classical Exchange Algebra of the Nonlinear Sigma Model on a Supercoset Target with Z2n Grading

    International Nuclear Information System (INIS)

    The classical exchange algebra satisfied by the monodromy matrix of the nonlinear sigma model on a supercoset target with Z2n grading is derived using a first-order Hamiltonian formulation and by adding to the Lax connection terms proportional to constraints. This enables us to show that the conserved charges of the theory are in involution. When n = 2, our results coincide with the results given by Magro for the pure spinor description of AdS5 × S5 string theory (when the ghost terms are omitted). (the physics of elementary particles and fields)

  15. Calculation of Vertical Mixing in Plane TUrbulent Buoyant Jets on the Basis of the Algebraic Model of Turbulence

    Institute of Scientific and Technical Information of China (English)

    O.G.Martynenko; V.N.Korovkin

    1992-01-01

    An algebraic model of turbulence,involving buyancy forces,is used for calculating velocity and temperature fields in plane turbulent vertical jets in a non-homogeneous stagnant medium,A new approach to the solution of the governing system of partial differential differental equations (Continuity ,Conservation of momentum,heat (buoyancy),turbulent kinetic energy,dissipation rate and mean quadratic temperature fluctuation)is suggested which is based on the intrduction of mathematical variables.Comparison is made between the results of the present calculations with experimental and numerical data of ther authors.

  16. Concurrence of Quantum States: Algebraic Dynamical Method Study XXX Models in a Time-Depending Random External Field

    International Nuclear Information System (INIS)

    Based on algebraic dynamics and the concept of the concurrence of the entanglement, we investigate the evolutive properties of the two-qubit entanglement that formed by Heisenberg XXX models under a time-depending external held. For this system, the property of the concurrence that is only dependent on the coupling constant J and total values of the external field is proved. Furthermore, we found that the thermal concurrence of the system under a static random external field is a function of the coupling constant J, temperature T, and the magnitude of external held. (general)

  17. Algebraic modeling and thermodynamic design of fan-supplied tube-fin evaporators running under frosting conditions

    International Nuclear Information System (INIS)

    In this study, the method of entropy generation minimization (i.e., design aimed at facilitating both heat, mass and fluid flows) is used to assess the evaporator design (aspect ratio and fin density) considering the thermodynamic losses due to heat and mass transfer, and viscous flow processes. A fully algebraic model was put forward to simulate the thermal-hydraulic behavior of tube-fin evaporator coils running under frosting conditions. The model predictions were validated against experimental data, showing a good agreement between calculated and measured counterparts. The optimization exercise has pointed out that high aspect ratio heat exchanger designs lead to lower entropy generation in cases of fixed cooling capacity and air flow rate constrained by the characteristic curve of the fan. - Highlights: • An algebraic model for frost accumulation on tube-fin heat exchangers was advanced. • Model predictions for cooling capacity and air flow rate were compared with experimental data, with errors within ±5% band. • Minimum entropy generation criterion was used to optimize the evaporator geometry. • Thermodynamic analysis led to slender designs for fixed cooling capacity and fan characteristics

  18. New Model and Algorithm for Hardware/Software Partitioning

    Institute of Scientific and Technical Information of China (English)

    Ji-Gang Wu; Thambipillai Srikanthan; Guang-Wei Zou

    2008-01-01

    This paper focuses on the algorithmic aspects for the hardware/software (HW/SW) partitioning which searches a reasonable composition of hardware and software components which not only satisfies the constraint of hardware area but also optimizes the execution time. The computational model is extended so that all possible types of communications can be taken into account for the HW/SW partitioning. Also, a new dynamic programming algorithm is proposed on the basis of the computational model, in which source data, rather than speedup in previous work, of basic scheduling blocks are directly utilized to calculate the optimal solution. The proposed algorithm runs in O(n. A) for n code fragments and the available hardware area A. Simulation results show that the proposed algorithm solves the HW/SW partitioning without increase in running time, compared with the algorithm cited in the literature.

  19. Finitary Algebraic Superspace

    CERN Document Server

    Zapatrin, R R

    1998-01-01

    An algebraic scheme is suggested in which discretized spacetime turns out to be a quantum observable. As an example, a toy model producing spacetimes of four points with different topologies is presented. The possibility of incorporating this scheme into the framework of non-commutative differential geometry is discussed.

  20. Thinking Visually about Algebra

    Science.gov (United States)

    Baroudi, Ziad

    2015-01-01

    Many introductions to algebra in high school begin with teaching students to generalise linear numerical patterns. This article argues that this approach needs to be changed so that students encounter variables in the context of modelling visual patterns so that the variables have a meaning. The article presents sample classroom activities,…

  1. The Effect of Scheduling Models for Introductory Algebra on 9th-Grade Students, Test Scores and Grades

    Science.gov (United States)

    O'Hanlon, Angela L.

    2011-01-01

    The purpose of the study was to determine the effect of pacing and scheduling of algebra coursework on assigned 9th-grade students who traditionally would qualify for pre-algebra instruction and same course 9th-grade students who traditionally would qualify for standard algebra instruction. Students were selected based on completion of first-year…

  2. Improved Based on "Self-Adaptive Turning Rate" Model Algorithm

    Directory of Open Access Journals (Sweden)

    Xiuling He

    2013-06-01

    Full Text Available For tracking the object with tracking nonlinear, high maneuvering target,traditional interactive multiple model self-adaptive filter algorithm was usually adopted.The turning rate estimate was very important. However,the performance of turning rate algorithm was not so satisfactory in the  model.Thus,a new the average value turning rate algorithm based on self-adaptive turning model was proposed.Aiming at additional device for turning rate estimation turning model, the parameters α and β were introduced to adjust the roughness of turning rate.Aiming at target constant turning movement and orthogonal turning rate unequal, estimates, turning rate was used the average value model to reduce the noise and error influence. Simulation results showed that the proposed algorithm was more suitable for the objects with Nonlinear, high maneuvering target tracking and could remarkably reduce the sample,and thus achieve much better tracking performance.

  3. Comparison of parameter estimation algorithms in hydrological modelling

    DEFF Research Database (Denmark)

    Blasone, Roberta-Serena; Madsen, Henrik; Rosbjerg, Dan

    Local search methods have been applied successfully in calibration of simple groundwater models, but might fail in locating the optimum for models of increased complexity, due to the more complex shape of the response surface. Global search algorithms have been demonstrated to perform well for...... these types of models, although at a more expensive computational cost. The main purpose of this study is to investigate the performance of a global and a local parameter optimization algorithm, respectively, the Shuffled Complex Evolution (SCE) algorithm and the gradient-based Gauss......-Marquardt-Levenberg algorithm (implemented in the PEST software), when applied to a steady-state and a transient groundwater model. The results show that PEST can have severe problems in locating the global optimum and in being trapped in local regions of attractions. The global SCE procedure is, in general, more effective and...

  4. Classical Exchange Algebra of the Nonlinear Sigma Model on a Supercoset Target with Z2n Grading

    Institute of Scientific and Technical Information of China (English)

    KE San-Min; LI Xin-Ying; WANG Chun; YUE Rui-Hong

    2011-01-01

    The classical exchange algebra satisfied by the monodromy matrix of the nonlinear sigma model on a supercoset target with Z2n grading is derived using a first-order Hamiltonian formulation and by adding to the Lax connection terms proportional to constraints. This enables us to show that the conserved charges of the theory are in involution. When n = 2, our results coincide with the results given by Magro for the pure spinor description of AdS5 × S5 string theory (when the ghost terms are omitted).%The classical exchange algebra satisfied by the monodromy matrix of the nonlinear sigma model on a supercoset target with Z2n grading is derived using a first-order Hamiltonian formulation and by adding to the Lax connection terms proportional to constraints.This enables us to show that the conserved charges of the theory are in involution.When n =2,our results coincide with the results given by Magro for the pure spinor description of AdS5 × S5 string theory (when the ghost terms are omitted).Bena,Polchinski and Roiban[1] found an infinite number of non-local classically conserved charges for the Grecn-Schwarz superstring in AdS5 × S5 background.[2] Similar results were obtained for some other strings[3-9] that propagate in AdS space-time,as discussed in Refs.[7 9].Vallilo[10] showed that such charges also exist in the pure-spinor formalism of the superstring in AdS5 × S5.Bianchi and Klǔson[11] gave the current algebra of the pure-spinor superstring.Berkovits[12] proved that the nonlocal charges in the string theory are BRST-invariant and physical.

  5. Computers in nonassociative rings and algebras

    CERN Document Server

    Beck, Robert E

    1977-01-01

    Computers in Nonassociative Rings and Algebras provides information pertinent to the computational aspects of nonassociative rings and algebras. This book describes the algorithmic approaches for solving problems using a computer.Organized into 10 chapters, this book begins with an overview of the concept of a symmetrized power of a group representation. This text then presents data structures and other computational methods that may be useful in the field of computational algebra. Other chapters consider several mathematical ideas, including identity processing in nonassociative algebras, str

  6. Petri net model for analysis of concurrently processed complex algorithms

    Science.gov (United States)

    Stoughton, John W.; Mielke, Roland R.

    1986-01-01

    This paper presents a Petri-net model suitable for analyzing the concurrent processing of computationally complex algorithms. The decomposed operations are to be processed in a multiple processor, data driven architecture. Of particular interest is the application of the model to both the description of the data/control flow of a particular algorithm, and to the general specification of the data driven architecture. A candidate architecture is also presented.

  7. An algorithm for model reduction in large electric power systems

    Directory of Open Access Journals (Sweden)

    Ze?evi? A. I.

    1998-01-01

    Full Text Available Model reduction has become an important issue in the analysis of electric power systems, due to their constantly increasing size and complexity. In this paper we present a decomposition algorithm which is capable of reducing the number of equations in the model, while preserving the potential for parallel computation. A variety of experimental results are provided to illustrate the performance of the algorithm.

  8. Malware propagation modeling by the means of genetic algorithms

    OpenAIRE

    Goranin, N.; Čenys, A.

    2008-01-01

    Existing malware propagation models mainly concentrate to forecasting the number of infected computers in the initial propagation phase. In this article we propose a genetic algorithm based model for estimating the propagation rates of known and perspective Internet worms after their propagation reaches the satiation phase. Estimation algorithm is based on the known worms’ propagation strategies with correlated propagation rates analysis and is presented as a decision tree, generated by GAtre...

  9. Ising models and topological codes: classical algorithms and quantum simulation

    CERN Document Server

    Nest, M Van den

    2014-01-01

    We present an algorithm to approximate partition functions of 3-body classical Ising models on two-dimensional lattices of arbitrary genus, in the real-temperature regime. Even though our algorithm is purely classical, it is designed by exploiting a connection to topological quantum systems, namely the color codes. The algorithm performance is exponentially better than other approaches which employ mappings between partition functions and quantum state overlaps. In addition, our approach gives rise to a protocol for quantum simulation of such Ising models by simply measuring local observables on color codes.

  10. A Mining Algorithm for Extracting Decision Process Data Models

    Directory of Open Access Journals (Sweden)

    Cristina-Claudia DOLEAN

    2011-01-01

    Full Text Available The paper introduces an algorithm that mines logs of user interaction with simulation software. It outputs a model that explicitly shows the data perspective of the decision process, namely the Decision Data Model (DDM. In the first part of the paper we focus on how the DDM is extracted by our mining algorithm. We introduce it as pseudo-code and, then, provide explanations and examples of how it actually works. In the second part of the paper, we use a series of small case studies to prove the robustness of the mining algorithm and how it deals with the most common patterns we found in real logs.

  11. Seismotectonic models and CN algorithm: The case of Italy

    International Nuclear Information System (INIS)

    The CN algorithm is here utilized both for the intermediate term earthquake prediction and to validate the seismotectonic model of the Italian territory. Using the results of the analysis, made through the CN algorithm and taking into account the seismotectonic model, three areas, one for Northern Italy, one for Central Italy and one for Southern Italy, are defined. Two transition areas, between the three main areas are delineated. The earthquakes which occurred in these two areas contribute to the precursor phenomena identified by the CN algorithm in each main area. (author). 26 refs, 6 figs, 2 tabs

  12. Wavelets and quantum algebras

    International Nuclear Information System (INIS)

    A non-linear associative algebra is realized in terms of translation and dilation operators, and a wavelet structure generating algebra is obtained. We show that this algebra is a q-deformation of the Fourier series generating algebra, and reduces to this for certain value of the deformation parameter. This algebra is also homeomorphic with the q-deformed suq(2) algebra and some of its extensions. Through this algebraic approach new methods for obtaining the wavelets are introduced. (author). 20 refs

  13. Central simple Poisson algebras

    Institute of Scientific and Technical Information of China (English)

    SU; Yucai; XU; Xiaoping

    2004-01-01

    Poisson algebras are fundamental algebraic structures in physics and symplectic geometry. However, the structure theory of Poisson algebras has not been well developed. In this paper, we determine the structure of the central simple Poisson algebras related to locally finite derivations, over an algebraically closed field of characteristic zero.The Lie algebra structures of these Poisson algebras are in general not finitely-graded.

  14. The Onsager Algebra

    OpenAIRE

    El-Chaar, Caroline

    2012-01-01

    In this thesis, four realizations of the Onsager algebra are explored. We begin with its original definition as introduced by Lars Onsager. We then examine how the Onsager algebra can be presented as a Lie algebra with two generators and two relations. The third realization of the Onsager algebra consists of viewing it as an equivariant map algebra which then gives us the tools to classify its closed ideals. Finally, we examine the Onsager algebra as a subalgebra of the tetrahedron algebra. U...

  15. Asymptotic-group analysis of algebraic equations

    OpenAIRE

    Shamrovskii, A. D.; I. V. Andrianov; J. Awrejcewicz

    2004-01-01

    Both the method of asymptotic analysis and the theory of extension group are applied to study the Descates equation. The proposed algorithm allows to obtain various variants of simplification and can be easily generalized to their algebraic and differential equations.

  16. Decomposition of semigroup algebras

    CERN Document Server

    Boehm, Janko; Nitsche, Max Joachim

    2011-01-01

    Let A \\subseteq B be cancellative abelian semigroups, and let R be an integral domain. We show that the semigroup ring R[B] can be decomposed, as an R[A]-module, into a direct sum of R[A]-submodules of the quotient ring of R[A]. In the case of a finite extension of positive affine semigroup rings we obtain an algorithm computing the decomposition. When R[A] is a polynomial ring over a field we explain how to compute many ring-theoretic properties of R[B] in terms of this decomposition. In particular we obtain a fast algorithm to compute the Castelnuovo-Mumford regularity of homogeneous semigroup rings. As an application we confirm the Eisenbud-Goto conjecture in a range of new cases. Our algorithms are implemented in the Macaulay2 package MonomialAlgebras.

  17. Algebraic Reasoning in the Middle Grades: A View of Student Strategies in Pictorial and Algebraic System of Equations

    Science.gov (United States)

    Falcon, Raymond

    2009-01-01

    Teachers use action research in order to improve their teaching and student learning. This action research will analyze students' algebraic reasoning in finding values of variables in systems of equations pictorially and algebraically. This research will look at students solving linear systems of equations without knowing the algebraic algorithms.…

  18. Model theory and algebraic geometry an introduction to E. Hrushovski’s proof of the geometric Mordell-Lang conjecture

    CERN Document Server

    1998-01-01

    This introduction to the recent exciting developments in the applications of model theory to algebraic geometry, illustrated by E. Hrushovski's model-theoretic proof of the geometric Mordell-Lang Conjecture starts from very basic background and works up to the detailed exposition of Hrushovski's proof, explaining the necessary tools and results from stability theory on the way. The first chapter is an informal introduction to model theory itself, making the book accessible (with a little effort) to readers with no previous knowledge of model theory. The authors have collaborated closely to achieve a coherent and self- contained presentation, whereby the completeness of exposition of the chapters varies according to the existence of other good references, but comments and examples are always provided to give the reader some intuitive understanding of the subject.

  19. An Algorithm of Speaker Clustering Based on Model Distance

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-03-01

    Full Text Available An algorithm based on Model Distance (MD for spectral speaker clustering is proposed to deal with the shortcoming of general spectral clustering algorithm in describing the distribution of signal source. First, an Universal Background Model (UBM is created with a large quantity of independent speakers; Then, Gaussian Mixture Model (GMM is trained from the UBM for every speech segment; At last, the probability distance between the GMM of every speech segment is used to build affinity matrix, and speaker spectral clustering is done on the affinity matrix. Experimental results based on news and conference data sets show that an average of 6.38% improvements in F measure is obtained in comparison with algorithm based on the feature vector distance. In addition, the proposed algorithm is 11.72 times faster

  20. Quantitative Methods in Supply Chain Management Models and Algorithms

    CERN Document Server

    Christou, Ioannis T

    2012-01-01

    Quantitative Methods in Supply Chain Management presents some of the most important methods and tools available for modeling and solving problems arising in the context of supply chain management. In the context of this book, “solving problems” usually means designing efficient algorithms for obtaining high-quality solutions. The first chapter is an extensive optimization review covering continuous unconstrained and constrained linear and nonlinear optimization algorithms, as well as dynamic programming and discrete optimization exact methods and heuristics. The second chapter presents time-series forecasting methods together with prediction market techniques for demand forecasting of new products and services. The third chapter details models and algorithms for planning and scheduling with an emphasis on production planning and personnel scheduling. The fourth chapter presents deterministic and stochastic models for inventory control with a detailed analysis on periodic review systems and algorithmic dev...

  1. Constructing semisimple subalgebras of semisimple Lie algebras

    CERN Document Server

    de Graaf, Willem A

    2010-01-01

    Algorithms are described that help with obtaining a classification of the semisimple subalgebras of a given semisimple Lie algebra, up to linear equivalence. The algorithms have been used to obtain classifications of the semisimple subalgebras of the simple Lie algebras of ranks <= 8. These have been made available as a database inside the SLA package of GAP4. The subalgebras in this database are explicitly given, as well as the inclusion relations among them.

  2. Three-Dimensional Algebraic Models of the tRNA Code and 12 Graphs for Representing the Amino Acids

    Directory of Open Access Journals (Sweden)

    Marco V. José

    2014-08-01

    Full Text Available Three-dimensional algebraic models, also called Genetic Hotels, are developed to represent the Standard Genetic Code, the Standard tRNA Code (S-tRNA-C, and the Human tRNA code (H-tRNA-C. New algebraic concepts are introduced to be able to describe these models, to wit, the generalization of the 2n-Klein Group and the concept of a subgroup coset with a tail. We found that the H-tRNA-C displayed broken symmetries in regard to the S-tRNA-C, which is highly symmetric. We also show that there are only 12 ways to represent each of the corresponding phenotypic graphs of amino acids. The averages of statistical centrality measures of the 12 graphs for each of the three codes are carried out and they are statistically compared. The phenotypic graphs of the S-tRNA-C display a common triangular prism of amino acids in 10 out of the 12 graphs, whilst the corresponding graphs for the H-tRNA-C display only two triangular prisms. The graphs exhibit disjoint clusters of amino acids when their polar requirement values are used. We contend that the S-tRNA-C is in a frozen-like state, whereas the H-tRNA-C may be in an evolving state.

  3. Analyzing the nonlinear vibrational wave differential equation for the simplified model of Tower Cranes by Algebraic Method

    Science.gov (United States)

    Akbari, M. R.; Ganji, D. D.; Ahmadi, A. R.; Kachapi, Sayyid H. Hashemi

    2014-03-01

    In the current paper, a simplified model of Tower Cranes has been presented in order to investigate and analyze the nonlinear differential equation governing on the presented system in three different cases by Algebraic Method (AGM). Comparisons have been made between AGM and Numerical Solution, and these results have been indicated that this approach is very efficient and easy so it can be applied for other nonlinear equations. It is citable that there are some valuable advantages in this way of solving differential equations and also the answer of various sets of complicated differential equations can be achieved in this manner which in the other methods, so far, they have not had acceptable solutions. The simplification of the solution procedure in Algebraic Method and its application for solving a wide variety of differential equations not only in Vibrations but also in different fields of study such as fluid mechanics, chemical engineering, etc. make AGM be a powerful and useful role model for researchers in order to solve complicated nonlinear differential equations.

  4. Models and algorithms for stochastic online scheduling

    NARCIS (Netherlands)

    Megow, N.; Uetz, M.J.; Vredeveld, T.

    2006-01-01

    We consider a model for scheduling under uncertainty. In this model, we combine the main characteristics of online and stochastic scheduling in a simple and natural way. Job processing times are assumed to be stochastic, but in contrast to traditional stochastic scheduling models, we assume that job

  5. Exotic Elliptic Algebras

    OpenAIRE

    Chirvasitu, Alex; Smith, S. Paul

    2015-01-01

    This paper examines a general method for producing twists of a comodule algebra by tensoring it with a torsor then taking co-invariants. We examine the properties that pass from the original algebra to the twisted algebra and vice versa. We then examine the special case where the algebra is a 4-dimensional Sklyanin algebra viewed as a comodule algebra over the Hopf algebra of functions on the non-cyclic group of order 4 with the torsor being the 2x2 matrix algebra. The twisted algebra is an "...

  6. Real Hamiltonian Forms of Affine Toda Models Related to Exceptional Lie Algebras

    Directory of Open Access Journals (Sweden)

    Vladimir S. Gerdjikov

    2006-02-01

    Full Text Available The construction of a family of real Hamiltonian forms (RHF for the special class of affine 1+1-dimensional Toda field theories (ATFT is reported. Thus the method, proposed in [1] for systems with finite number of degrees of freedom is generalized to infinite-dimensional Hamiltonian systems. The construction method is illustrated on the explicit nontrivial example of RHF of ATFT related to the exceptional algebras E_6 and E_7. The involutions of the local integrals of motion are proved by means of the classical R-matrix approach.

  7. An Ada Linear-Algebra Software Package Modeled After HAL/S

    Science.gov (United States)

    Klumpp, Allan R.; Lawson, Charles L.

    1990-01-01

    New avionics software written more easily. Software package extends Ada programming language to include linear-algebra capabilities similar to those of HAL/S programming language. Designed for such avionics applications as Space Station flight software. In addition to built-in functions of HAL/S, package incorporates quaternion functions used in Space Shuttle and Galileo projects and routines from LINPAK solving systems of equations involving general square matrices. Contains two generic programs: one for floating-point computations and one for integer computations. Written on IBM/AT personal computer running under PC DOS, v.3.1.

  8. The max-plus algebra approach in modelling of queueing networks

    OpenAIRE

    Krivulin, Nikolai K.

    2012-01-01

    A class of queueing networks which consist of single-server fork-join nodes with infinite buffers is examined to derive a representation of the network dynamics in terms of max-plus algebra. For the networks, we present a common dynamic state equation which relates the departure epochs of customers from the network nodes in an explicit vector form determined by a state transition matrix. We show how the matrix may be calculated from the service time of customers in the general case, and give ...

  9. Heisenberg XXX Model with General Boundaries: Eigenvectors from Algebraic Bethe Ansatz

    Directory of Open Access Journals (Sweden)

    Samuel Belliard

    2013-11-01

    Full Text Available We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations formally similar to the ones obtained in the periodic case or with diagonal boundaries.

  10. Algebraic Bethe ansatz for the sl(2) Gaudin model with boundary

    CERN Document Server

    António, N Cirilo; Ragoucy, E; Salom, I

    2015-01-01

    Following Sklyanin's proposal in the periodic case, we derive the generating function of the Gaudin Hamiltonians with boundary terms. Our derivation is based on the quasi-classical expansion of the linear combination of the transfer matrix of the XXX Heisenberg spin chain and the central element, the so-called Sklyanin determinant. The corresponding Gaudin Hamiltonians with boundary terms are obtained as the residues of the generating function. By defining the appropriate Bethe vectors which yield strikingly simple off shell action of the generating function, we fully implement the algebraic Bethe ansatz, obtaining the spectrum of the generating function and the corresponding Bethe equations.

  11. Algebraic Bethe ansatz for the XXX chain with triangular boundaries and Gaudin model

    CERN Document Server

    António, N Cirilo; Salom, I

    2014-01-01

    We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the corresponding Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the Bethe vectors through the so-called quasi-classical limit.

  12. Heisenberg XXX Model with General Boundaries: Eigenvectors from Algebraic Bethe Ansatz

    Science.gov (United States)

    Belliard, Samuel; Crampé, Nicolas

    2013-11-01

    We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations) formally similar to the ones obtained in the periodic case or with diagonal boundaries.

  13. Heisenberg XXX model with general boundaries: Eigenvectors from Algebraic Bethe ansatz

    CERN Document Server

    Belliard, S

    2013-01-01

    We propose a generalization of the algebraic Bethe ansatz to obtain the eigenvectors of the Heisenberg spin chain with general boundaries associated to the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz takes the usual form of a product of operators acting on a particular vector except that the number of operators is equal to the length of the chain. We prove this result for the chains with small length. We obtain also an off-shell equation (i.e. satisfied without the Bethe equations) formally similar to the ones obtained in the periodic case or with diagonal boundaries.

  14. Invariants of Lie algebras with fixed structure of nilradicals

    International Nuclear Information System (INIS)

    An algebraic algorithm is developed for computation of invariants ('generalized Casimir operators') of general Lie algebras over the real or complex number field. Its main tools are the Cartan's method of moving frames and the knowledge of the group of inner automorphisms of each Lie algebra. Unlike the first application of the algorithm in Boyko et al (2006 J. Phys. A: Math. Gen. 39 5749 (Preprint math-ph/0602046)), which deals with low-dimensional Lie algebras, here the effectiveness of the algorithm is demonstrated by its application to computation of invariants of solvable Lie algebras of general dimension n < ∞ restricted only by a required structure of the nilradical. Specifically, invariants are calculated here for families of real/complex solvable Lie algebras. These families contain, with only a few exceptions, all the solvable Lie algebras of specific dimensions, for whom the invariants are found in the literature

  15. DiamondTorre Algorithm for High-Performance Wave Modeling

    Directory of Open Access Journals (Sweden)

    Vadim Levchenko

    2016-08-01

    Full Text Available Effective algorithms of physical media numerical modeling problems’ solution are discussed. The computation rate of such problems is limited by memory bandwidth if implemented with traditional algorithms. The numerical solution of the wave equation is considered. A finite difference scheme with a cross stencil and a high order of approximation is used. The DiamondTorre algorithm is constructed, with regard to the specifics of the GPGPU’s (general purpose graphical processing unit memory hierarchy and parallelism. The advantages of these algorithms are a high level of data localization, as well as the property of asynchrony, which allows one to effectively utilize all levels of GPGPU parallelism. The computational intensity of the algorithm is greater than the one for the best traditional algorithms with stepwise synchronization. As a consequence, it becomes possible to overcome the above-mentioned limitation. The algorithm is implemented with CUDA. For the scheme with the second order of approximation, the calculation performance of 50 billion cells per second is achieved. This exceeds the result of the best traditional algorithm by a factor of five.

  16. Nonmonotonic logics and algebras

    Institute of Scientific and Technical Information of China (English)

    CHAKRABORTY Mihir Kr; GHOSH Sujata

    2008-01-01

    Several nonmonotonie logic systems together with their algebraic semantics are discussed. NM-algebra is defined.An elegant construction of an NM-algebra starting from a Boolean algebra is described which gives rise to a few interesting algebraic issues.

  17. Fibered F-Algebra

    OpenAIRE

    Kleyn, Aleks

    2007-01-01

    The concept of F-algebra and its representation can be extended to an arbitrary bundle. We define operations of fibered F-algebra in fiber. The paper presents the representation theory of of fibered F-algebra as well as a comparison of representation of F-algebra and of representation of fibered F-algebra.

  18. Geometric Algebra Computing

    CERN Document Server

    Corrochano, Eduardo Bayro

    2010-01-01

    This book presents contributions from a global selection of experts in the field. This useful text offers new insights and solutions for the development of theorems, algorithms and advanced methods for real-time applications across a range of disciplines. Written in an accessible style, the discussion of all applications is enhanced by the inclusion of numerous examples, figures and experimental analysis. Features: provides a thorough discussion of several tasks for image processing, pattern recognition, computer vision, robotics and computer graphics using the geometric algebra framework; int

  19. Combinatorial frameworks for cluster algebras

    CERN Document Server

    Reading, Nathan

    2011-01-01

    We develop a general approach to finding combinatorial models for cluster algebras. The approach is to construct a labeled graph called a framework. When a framework is constructed with certain properties, the result is a model incorporating information about exchange matrices, principal coefficients, g-vectors, g-vector fans, and (conjecturally) denominator vectors. The idea behind frameworks arises from Cambrian combinatorics and sortable elements, and in this paper, we use sortable elements to construct a framework for any cluster algebra with an acyclic initial exchange matrix. This Cambrian framework yields a model of the entire (principal coefficients) exchange graph when the cluster algebra is of finite type. Outside of finite type, the Cambrian framework models only part of the exchange graph. In a forthcoming paper, we extend the Cambrian construction to produce a complete framework for a cluster algebra whose associated Cartan matrix is of affine type.

  20. Asymptotic algebra of quantum electrodynamics

    OpenAIRE

    Herdegen, Andrzej

    2004-01-01

    The Staruszkiewicz quantum model of the long-range structure in electrodynamics is reviewed in the form of a Weyl algebra. This is followed by a personal view on the asymptotic structure of quantum electrodynamics.

  1. A NEW GENETIC SIMULATED ANNEALING ALGORITHM FOR FLOOD ROUTING MODEL

    Institute of Scientific and Technical Information of China (English)

    KANG Ling; WANG Cheng; JIANG Tie-bing

    2004-01-01

    In this paper, a new approach, the Genetic Simulated Annealing (GSA), was proposed for optimizing the parameters in the Muskingum routing model. By integrating the simulated annealing method into the genetic algorithm, the hybrid method could avoid some troubles of traditional methods, such as arduous trial-and-error procedure, premature convergence in genetic algorithm and search blindness in simulated annealing. The principle and implementing procedure of this algorithm were described. Numerical experiments show that the GSA can adjust the optimization population, prevent premature convergence and seek the global optimal result.Applications to the Nanyunhe River and Qingjiang River show that the proposed approach is of higher forecast accuracy and practicability.

  2. Grid Dependent Tasks Security Scheduling Model and DPSO Algorithm

    Directory of Open Access Journals (Sweden)

    Hai Zhu

    2011-06-01

    Full Text Available Due to the security threat to task scheduling problems in the grid environment, by considering both the inherent security and behavior safety of grid resource nodes, security benefit functions and credibility assessment strategies of grid resource nodes are constructed respectively. At the same time, the corresponding membership function is established in order to establish the membership between task security requirements and resource security attributes. Based on these, a new grid dependent tasks security scheduling model is set up. In order to solve this model, the particle evolution equation is re-designed by combining the specific characteristics of the dependent task scheduling problem. Meanwhile, in order to prevent the algorithm falling into local optimum, a uniform speed of disturbance is adopted and a new discrete Particle Swarm Optimization algorithm is proposed. Simulation results show that this algorithm has better scheduling length and higher safety performance than the genetic algorithm.

  3. Research on the active cloud computing algorithm model

    Science.gov (United States)

    Wang, Denghui; Huang, Hao; Xie, Changsheng

    The efficiency of Service composition optimal solution algorithm depends on the structure of the user requirement model. MLQEM (Multi-level Hybrid QoS Extended Model) provides a multi-level hybrid QoS structure. This structure allows users to actively give the specific constraint conditions about the professional field of web service. The number of user constraint conditions increase that increase the calculation of the current global optimization algorithm. In this paper we propose a new kind of algorithm MLHSA based on MLQEM. We integrate local optimal strategy and global optimal strategy in different levels of QoS. At last our experimental result indicate that MLHSA algorithm are improved obviously in efficiency and accuracy.

  4. Implementing Modifed Burg Algorithms in Multivariate Subset Autoregressive Modeling

    Directory of Open Access Journals (Sweden)

    A. Alexandre Trindade

    2003-02-01

    Full Text Available The large number of parameters in subset vector autoregressive models often leads one to procure fast, simple, and efficient alternatives or precursors to maximum likelihood estimation. We present the solution of the multivariate subset Yule-Walker equations as one such alternative. In recent work, Brockwell, Dahlhaus, and Trindade (2002, show that the Yule-Walker estimators can actually be obtained as a special case of a general recursive Burg-type algorithm. We illustrate the structure of this Algorithm, and discuss its implementation in a high-level programming language. Applications of the Algorithm in univariate and bivariate modeling are showcased in examples. Univariate and bivariate versions of the Algorithm written in Fortran 90 are included in the appendix, and their use illustrated.

  5. Multiple QoS modeling and algorithm in computational grid

    Institute of Scientific and Technical Information of China (English)

    Li Chunlin; Feng Meilai; Li Layuan

    2007-01-01

    Multiple QoS modeling and algorithm in grid system is considered.Grid QoS requirements can be formulated as a utility function for each task as a weighted sum of its each dimensional QoS utility functions.Multiple QoS constraint resource scheduling optimization in computational grid is distributed to two subproblems: optimization of grid user and grid resource provider.Grid QoS scheduling can be achieved by solving sub problems via an iterative algorithm.

  6. Algebraic structures in quantum gravity

    CERN Document Server

    Tanasa, Adrian

    2009-01-01

    Starting from a recently-introduced algebraic structure on spin foam models, we define a Hopf algebra by dividing with an appropriate quotient. The structure, thus defined, naturally allows for a mirror analysis of spin foam models with quantum field theory, from a combinatorial point of view. A grafting operator is introduced allowing for the equivalent of a Dyson-Schwinger equation to be written. Non-trivial examples are explicitly worked out. Finally, the physical significance of the results is discussed.

  7. Quantum solvable models with gl(2, c) Lie algebra symmetry embedded into the extension of unitary parasupersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, H [Department of Theoretical Physics and Astrophysics, Physics Faculty, University of Tabriz, PO Box 51666-16471, Tabriz (Iran, Islamic Republic of); Chenaghlou, A [Research Institute for Fundamental Sciences, Tabriz (Iran, Islamic Republic of)

    2007-05-25

    Introducing p - 1 new parameters into the multilinear relations, we extend the standard unitary parasupersymmetry algebra of order p so that by embedding the quantum solvable models possessing gl(2, c) Lie algebra symmetry into it, the partitions of integer numbers p - 1 and 1/2 p(p-1) are established. These two partitions are performed by the new parameters and the product of new parameters with their labels, respectively. The former partition is just necessary for the real form h{sub 4}; however, both of them are essential for the real forms u(2) and u(1, 1). By occupying these parameters with arbitrary values, the energy spectra are determined by the mean value of proposed parameters for the real form h{sub 4} with their label weight function as well as for the real forms u(2) and u(1, 1) with the weight function of their squared label. So for the given energies, the multilinear behaviour of parasupercharges is not specified uniquely by varying the new parameters continuously.

  8. Quantum solvable models with gl(2, c) Lie algebra symmetry embedded into the extension of unitary parasupersymmetry

    Science.gov (United States)

    Fakhri, H.; Chenaghlou, A.

    2007-05-01

    Introducing p - 1 new parameters into the multilinear relations, we extend the standard unitary parasupersymmetry algebra of order p so that by embedding the quantum solvable models possessing gl(2, c) Lie algebra symmetry into it, the partitions of integer numbers p - 1 and \\frac{1}{2}p(p-1) are established. These two partitions are performed by the new parameters and the product of new parameters with their labels, respectively. The former partition is just necessary for the real form h4; however, both of them are essential for the real forms u(2) and u(1, 1). By occupying these parameters with arbitrary values, the energy spectra are determined by the mean value of proposed parameters for the real form h4 with their label weight function as well as for the real forms u(2) and u(1, 1) with the weight function of their squared label. So for the given energies, the multilinear behaviour of parasupercharges is not specified uniquely by varying the new parameters continuously.

  9. Quantum solvable models with gl(2, c) Lie algebra symmetry embedded into the extension of unitary parasupersymmetry

    International Nuclear Information System (INIS)

    Introducing p - 1 new parameters into the multilinear relations, we extend the standard unitary parasupersymmetry algebra of order p so that by embedding the quantum solvable models possessing gl(2, c) Lie algebra symmetry into it, the partitions of integer numbers p - 1 and 1/2 p(p-1) are established. These two partitions are performed by the new parameters and the product of new parameters with their labels, respectively. The former partition is just necessary for the real form h4; however, both of them are essential for the real forms u(2) and u(1, 1). By occupying these parameters with arbitrary values, the energy spectra are determined by the mean value of proposed parameters for the real form h4 with their label weight function as well as for the real forms u(2) and u(1, 1) with the weight function of their squared label. So for the given energies, the multilinear behaviour of parasupercharges is not specified uniquely by varying the new parameters continuously

  10. Algebraic Reynolds stress modeling of turbulence subject to rapid homogeneous and non-homogeneous compression or expansion

    Science.gov (United States)

    Grigoriev, I. A.; Wallin, S.; Brethouwer, G.; Grundestam, O.; Johansson, A. V.

    2016-02-01

    A recently developed explicit algebraic Reynolds stress model (EARSM) by Grigoriev et al. ["A realizable explicit algebraic Reynolds stress model for compressible turbulent flow with significant mean dilatation," Phys. Fluids 25(10), 105112 (2013)] and the related differential Reynolds stress model (DRSM) are used to investigate the influence of homogeneous shear and compression on the evolution of turbulence in the limit of rapid distortion theory (RDT). The DRSM predictions of the turbulence kinetic energy evolution are in reasonable agreement with RDT while the evolution of diagonal components of anisotropy correctly captures the essential features, which is not the case for standard compressible extensions of DRSMs. The EARSM is shown to give a realizable anisotropy tensor and a correct trend of the growth of turbulence kinetic energy K, which saturates at a power law growth versus compression ratio, as well as retaining a normalized strain in the RDT regime. In contrast, an eddy-viscosity model results in a rapid exponential growth of K and excludes both realizability and high magnitude of the strain rate. We illustrate the importance of using a proper algebraic treatment of EARSM in systems with high values of dilatation and vorticity but low shear. A homogeneously compressed and rotating gas cloud with cylindrical symmetry, related to astrophysical flows and swirling supercritical flows, was investigated too. We also outline the extension of DRSM and EARSM to include the effect of non-homogeneous density coupled with "local mean acceleration" which can be important for, e.g., stratified flows or flows with heat release. A fixed-point analysis of direct numerical simulation data of combustion in a wall-jet flow demonstrates that our model gives quantitatively correct predictions of both streamwise and cross-stream components of turbulent density flux as well as their influence on the anisotropies. In summary, we believe that our approach, based on a proper

  11. A LOAD BALANCING MODEL USING FIREFLY ALGORITHM IN CLOUD COMPUTING

    Directory of Open Access Journals (Sweden)

    A. Paulin Florence

    2014-01-01

    Full Text Available Cloud computing is a model that points at streamlining the on-demand provisioning of software, hardware and data as services and providing end-users with flexible and scalable services accessible through the Internet. The main objective of the proposed approach is to maximize the resource utilization and provide a good balanced load among all the resources in cloud servers. Initially, a load model of every resource will be derived based on several factors such as, memory usage, processing time and access rate. Based on the newly derived load index, the current load will be computed for all the resources shared in virtual machine of cloud servers. Once the load index is computed for all the resources, load balancing operation will be initiated to effectively use the resources dynamically with the process of assigning resources to the corresponding node to reduce the load value. So, assigning of resources to proper nodes is an optimal distribution problem so that many optimization algorithms such as genetic algorithm and modified genetic algorithm are utilized for load balancing. These algorithms are not much effective in providing the neighbour solutions since it does not overcome exploration and exploration problem. So, utilizing the effective optimization procedure instead of genetic algorithm can lead to better load balancing since it is a traditional and old algorithm. Accordingly, I have planned to utilize a recent optimization algorithm, called firefly algorithm to do the load balancing operation in our proposed work. At first, the index table will be maintained by considering the availability of virtual servers and sequence of request. Then, load index will be computed based on the newly derived formulae. Based on load index, load balancing operation will be carried out using firefly algorithm. The performance analysis produced expected results and thus proved the proposed approach is efficient in optimizing schedules by balancing the

  12. Algorithms and technologies for photonic crystal modelling

    OpenAIRE

    Hart, Elizabeth E.

    2009-01-01

    In this thesis an investigation into the behaviour of light when passing through photonic crystals was carried out using numerical methods. Photonic crystals are expensive and difficult to fabricate so there is a requirement for computer simulations that can quickly and accurately model how the crystal structure will affect the behaviour of light. A finite difference method was written to model two-dimensional photonic crystals. The results from the finite difference method mod...

  13. Algorithm for Model Validation: Theory and Implementation

    CERN Document Server

    Sornette, D; Ide, K; Kamm, J R; Pisarenko, V; Vixie, K R

    2005-01-01

    Validation is often defined as the process of determining the degree to which a model is an accurate representation of the real world from the perspective of its intended uses. Validation is crucial as industries and governments depend increasingly on predictions by computer models to justify their decisions. We propose to formulate the validation of a given model/code as an iterative construction process that mimics the often implicit process occurring in the minds of scientists. We offer a formal representation of the progressive build-up of trust in the model. We thus replace static claims on the impossibility of validating a given model/code by a dynamic process of constructive approximation. This approach is better adapted to the fuzzy, coarse-grained nature of validation. Our procedure factors in the degree of redundancy versus novelty of the experiments used for validation as well as the degree to which the model predicts the observations. We illustrate the new methodology first with the maturation of ...

  14. Algorithmic tools for simulations of vertex models on random graphs

    International Nuclear Information System (INIS)

    We consider the coupling of ice-type vertex models to random, planar phi4 quantum-gravity graphs. The well-established techniques for the simulation of dynamical triangulations and their dual phi3 graphs are suitably adapted to the case of four-valent graphs. These methods are combined with a formulation of the loop algorithm for the simulation of the vertex model matter part. We present a preliminary analysis of the dynamical scaling behaviour of the combined algorithm for the case of the 6-vertex model coupled to quantum gravity

  15. How to incorporate generic refraction models into multistatic tracking algorithms

    Science.gov (United States)

    Crouse, D. F.

    The vast majority of literature published on target tracking ignores the effects of atmospheric refraction. When refraction is considered, the solutions are generally tailored to a simple exponential atmospheric refraction model. This paper discusses how arbitrary refraction models can be incorporated into tracking algorithms. Attention is paid to multistatic tracking problems, where uncorrected refractive effects can worsen track accuracy and consistency in centralized tracking algorithms, and can lead to difficulties in track-to-track association in distributed tracking filters. Monostatic and bistatic track initialization using refraction-corrupted measurements is discussed. The results are demonstrated using an exponential refractive model, though an arbitrary refraction profile can be substituted.

  16. On Models of Nonlinear Evolution Paths in Adiabatic Quantum Algorithms

    International Nuclear Information System (INIS)

    In this paper, we study two different nonlinear interpolating paths in adiabatic evolution algorithms for solving a particular class of quantum search problems where both the initial and final Hamiltonian are one-dimensional projector Hamiltonians on the corresponding ground state. If the overlap between the initial state and final state of the quantum system is not equal to zero, both of these models can provide a constant time speedup over the usual adiabatic algorithms by increasing some another corresponding “complexity. But when the initial state has a zero overlap with the solution state in the problem, the second model leads to an infinite time complexity of the algorithm for whatever interpolating functions being applied while the first one can still provide a constant running time. However, inspired by a related reference, a variant of the first model can be constructed which also fails for the problem when the overlap is exactly equal to zero if we want to make up the 'intrinsic' fault of the second model — an increase in energy. Two concrete theorems are given to serve as explanations why neither of these two models can improve the usual adiabatic evolution algorithms for the phenomenon above. These just tell us what should be noted when using certain nonlinear evolution paths in adiabatic quantum algorithms for some special kind of problems. (general)

  17. A wave equation including leptons and quarks for the standard model of quantum physics in Clifford Algebra

    CERN Document Server

    Daviau, Claude

    2014-01-01

    A wave equation with mass term is studied for all particles and antiparticles of the first generation: electron and its neutrino, positron and antineutrino, quarks $u$ and $d$ with three states of color and antiquarks $\\overline{u}$ and $\\overline{d}$. This wave equation is form invariant under the $Cl_3^*$ group generalizing the relativistic invariance. It is gauge invariant under the $U(1)\\times SU(2) \\times SU(3)$ group of the standard model of quantum physics. The wave is a function of space and time with value in the Clifford algebra $Cl_{1,5}$. All features of the standard model, charge conjugation, color, left waves, Lagrangian formalism, are linked to the geometry of this extended space-time.

  18. A Wave Equation including Leptons and Quarks for the Standard Model of Quantum Physics in Clifford Algebra

    Science.gov (United States)

    Daviau, Claude; Bertrand, Jacques

    A wave equation with mass term is studied for all particles and antiparticles of the first generation: electron and its neutrino, positron and antineutrino, quarks $u$ and $d$ with three states of color and antiquarks $\\overline{u}$ and $\\overline{d}$. This wave equation is form invariant under the $Cl_3^*$ group generalizing the relativistic invariance. It is gauge invariant under the $U(1)\\times SU(2) \\times SU(3)$ group of the standard model of quantum physics. The wave is a function of space and time with value in the Clifford algebra $Cl_{1,5}$. All features of the standard model, charge conjugation, color, left waves, Lagrangian formalism, are linked to the geometry of this extended space-time.

  19. Hospital Case Cost Estimates Modelling - Algorithm Comparison

    CERN Document Server

    Andru, Peter

    2008-01-01

    Ontario (Canada) Health System stakeholders support the idea and necessity of the integrated source of data that would include both clinical (e.g. diagnosis, intervention, length of stay, case mix group) and financial (e.g. cost per weighted case, cost per diem) characteristics of the Ontario healthcare system activities at the patient-specific level. At present, the actual patient-level case costs in the explicit form are not available in the financial databases for all hospitals. The goal of this research effort is to develop financial models that will assign each clinical case in the patient-specific data warehouse a dollar value, representing the cost incurred by the Ontario health care facility which treated the patient. Five mathematical models have been developed and verified using real dataset. All models can be classified into two groups based on their underlying method: 1. Models based on using relative intensity weights of the cases, and 2. Models based on using cost per diem.

  20. Model Specification Searches Using Ant Colony Optimization Algorithms

    Science.gov (United States)

    Marcoulides, George A.; Drezner, Zvi

    2003-01-01

    Ant colony optimization is a recently proposed heuristic procedure inspired by the behavior of real ants. This article applies the procedure to model specification searches in structural equation modeling and reports the results. The results demonstrate the capabilities of ant colony optimization algorithms for conducting automated searches.